prudentmind

Efficiency enhancement of stationary solar energy based power conversion systems in Canada

2009-05-11T00:07:00.004-07:00

Abstract
This paper presents the optimum energy conversion conditions of stationary photovoltaic panels used for electrical power generation. The results are arrived at after performing calculations for 180 days in a given year at the latitude of St. John’s, Newfoundland. The latitude of this city is close to other Canadian major population centers. Various angular orientations of sun’s rays on the earth are considered. On a given day, the incident energy flux of sun is resolved into three components, and the conversion efficiency is based on the flux normal to the panels. The efficiency of conversion of the incident energy is measured with respect to a solar tracking process. The numbers of days in a given year are divided into two groups – one between the winter solstice and the spring equinox, and another between the spring equinox and the summer solstice.
The results show the existence of two maxima, one for each of the two periods. By setting the panels at each of these maxima, very significant improvement in energy conversion can be achieved.

Article Outline
Nomenclature
1. Introduction
2. Theoretical considerations
3. Results and discussions
4. Conclusions
References

Solar-powered cooling systems: Technical and economic analysis on industrial refrigeration and air-conditioning applications

2009-05-11T00:07:00.003-07:00

Abstract
In the last years, the growing demand for air conditioning has caused a significant increase in demand for primary energy resources. Solar-powered cooling is one of the technologies which allows to obtain, by using the renewable solar source, an important energy saving compared to traditional air conditioning plants. The paper describes different technical installations for solar cooling, their way of operation, advantages and limits. The objective of the present study has been to analyze the technical and economic feasibility of solar absorption cooling systems, designed for two different application fields: industrial refrigeration and air conditioning. The possibility to replace or integrate the existing plants is studied, by considering the refrigeration requirements of a company, which works in meat manufacturing, and the heating and cooling demands of a hotel located in a tourist town in Italy. In the first case, the system comprises an absorption chiller coupled to solar flat plate collectors, whereas the second application is about a hybrid trigeneration plant, known as thermo-solar trigeneration; this option allows having greater operational flexibility at sites with demand for energy in the form of heating as well as cooling, for example in a hotel. In this way the authors could compare different results obtained by a technical and economic experimental analysis based on existing users and evaluate the advantages and disadvantages in order to suggest the best solution for the two studied cases.
Article Outline
Nomenclature
1. Introduction
2. Technologies
2.1. Solar cooling
2.2. Thermo-solar trigeneration
2.3. State of the art
2.4. Financial aspects
3. First case study: industrial refrigeration
3.1. Installations
3.2. Plant design solutions
3.3. Technical and economic feasibility
4. Second case study: hotel users
4.1. Installed plants and recorded consumptions
4.2. Plant solution, technical and economic feasibility
5. Conclusions
Acknowledgements
References

Applications of porous media combustion technology – A review

2009-05-11T00:07:00.001-07:00

Abstract
The rapid advances in technology and improved living standard of the society necessitate abundant use of fossil fuels which poses two major challenges to any nation. One is fast depletion of fossil fuel resources; the other is environmental pollution. The porous medium combustion (PMC) has proved to be one of the feasible options to tackle the aforesaid problems to a remarkable extent. PMC has interesting advantages compared with free flame combustion due to the higher burning rates, the increased power dynamic range, the extension of the lean flammability limits, and the low emissions of pollutants. This article provides a comprehensive picture of the global scenario of applications of PMC so as to enable the researchers to decide the direction of further investigation. The works published so far in this area are reviewed, classified according to their objectives and presented in an organized manner with general conclusions.
Article Outline
1. Introduction
2. Conceptual background
2.1. Filtration combustion and excess enthalpy
2.2. Premixed and non-premixed combustion
3. Development of PM burners
3.1. Infrared heating
3.2. Patented burners
3.3. Attempts for innovative burners
4. Applications of PMC technology
4.1. IC engines
4.2. Gas turbines and propulsion
4.3. Heat exchangers
4.4. Oil and gas recovery
4.5. Lighting
4.6. Hydrogen production
4.7. Thermoelectric conversion and CHP
4.8. Combustion of low CV fuels
4.9. Solid fuel or powder combustion
4.10. HCl synthesis
4.11. VOC oxidation
4.12. Micro and meso-scale applications
4.13. Liquid fuel combustion (LFC)
4.14. Miscellaneous applications
5. Conclusions
Acknowledgements
References

Characterization of trace metals in vegetables by graphite furnace atomic absorption spectrometry after closed vessel microwave digestion

2009-05-11T00:06:00.004-07:00

Abstract
A simple and expeditious method for the determination of trace metals (cadmium, chromium, copper, manganese and lead) is proposed. The metals are extracted from their matrix by using nitric acid and hydrogen peroxide in a closed-vessel microwave digestion system for their subsequent detection by graphite furnace atomic absorption spectrometry (GFAAS). The sample preparation procedure facilitates the overall analytical process and enables the construction of calibration curves from inorganic standards. The ensuing method provides good linearity and sensitivity for the five metals, with limits of detection and quantization spanning the ranges 0.05–2.20 and 0.15–7.34 μg/kg, respectively. This sensitivity level is quite appropriate for the intended application. Accuracy was assessed by using a certified reference material (NCS ZC85006 Tomato), for which the proposed method provided amounts of metals consistent with their certified values. The proposed method was applied to tomato, pepper and onion, which are widely consumed in Mediterranean countries.
Article Outline
1. Introduction
2. Experimental
2.1. Instrumentation
2.2. Reagents and chemical standard
2.3. Sample treatment
2.4. Determination procedure
3. Results and discussion
3.1. Effect of experimental variables
3.2. Analytical performance
3.3. Analysis of vegetable samples
4. Conclusions
Acknowledgements
References

Assessing the performance of biogas plants with multi-criteria and data envelopment analysis

2009-05-11T00:06:00.003-07:00

Abstract
This paper performs an assessment of 41 agricultural biogas plants located in Austria to determine their relative performance in terms of economic, environmental, and social criteria and corresponding indicators. The comparison of these renewable energy conversion plants is based on two complementary analyses. Data envelopment analysis (DEA) was conducted to provide measures of radial efficiency relative to the observed frontier of production possibilities. Multi-criteria decision analysis (MCDA), using the IRIS/ELECTRE TRI methodology, was conducted to obtain a different perspective on the results, and as a tool that would enable to incorporate managerial preferences easily. To be able to use IRIS while keeping the spirit behind DEA, the evaluation criteria were defined as different output/input efficiency ratios, and no information about criteria weights was introduced at the outset. The results suggest that MCDA, and the use of IRIS in particular, constitutes a useful approach that can be applied in a complementary way to DEA.
Article Outline
1. Introduction
2. Comparison of analytical frameworks
2.1. DEA
2.2. MCDA
3. Case study
4. Results
4.1. Description of the data and parameters used
4.2. DEA
4.3. MCDA
4.4. Comparing the results
4.5. Further analyses with IRIS
5. Discussion and conclusions
Acknowledgements
References

Periodic solutions in a delayed predator–prey model with nonmonotonic functional response

2009-05-11T00:06:00.001-07:00

Abstract
By using the continuation theorem of coincidence degree theory and some functional analysis techniques, several existence criteria are established for positive periodic solutions of a delayed predator–prey model with nonmonotonic functional response of the form where a(t),b(t),μ(t) and d(t) are all positive periodic continuous functions with period ω>0, τ is a nonnegative constant and g is a nonmonotonic functional response function. And an example is given to illustrate our main result.
Article Outline
1. Introduction
2. Main result
3. An Example
References

A single stage-structured population model with mature individuals in a polluted environment and pulse input of environmental toxin

2009-05-11T00:05:00.006-07:00

Abstract
In this paper, we concentrates on the study of a single stage-structured population model with mature individuals in a polluted environment and pulse input of environmental toxin. A globally attractive condition for the population-extinction boundary periodic solution of the investigated system is obtained. Sufficient criteria on the permanence of the population are derived.
Article Outline
1. Introduction
2. Some important lemmas
3. Global attractivity and permanence
4. Discussion
References

Oscillatory behavior in microbial continuous culture with discrete time delay

2009-05-11T00:05:00.005-07:00

Abstract
By introducing discrete time delay into the model for producing 1,3-propanediol by microbial continuous fermentation, we consider the stability and Hopf bifurcation of the delay differential system. Through numerical simulations, we get the rule of branch value changing with parameter and draw the pictures of periodic solutions and phase diagrams with specified parameters. The effect of time delay suggests that the system can qualitatively describe oscillatory phenomena occurring in the experiment.
Article Outline
1. Introduction
2. Model of delay differential system in continuous culture
3. Stability of delay differential system
4. Existence of Hopf bifurcation
5. Numerical simulations
6. Conclusions
References

Policy directions for agricultural land use in Australia and other post-industrial economies

2009-05-11T00:05:00.003-07:00

Abstract
Farming has been the basis to work, culture and social forces for millennia. It still dominates the lives of most of the world's poorer people, but in post-industrial western countries agriculture's contribution to national economies is now minor. Nevertheless, most OECD countries’ agricultural policies are aimed at maintaining the size of this sector even where this conflicts with its economic significance or adversely affects the environment. Australia has a first world economy, but a third world export profile, with 20% of its export value derived from agriculture. Although it is efficient in agricultural man-power, this sector consumes 70% of the water and 60% of the land resources of the continent to produce food for an estimated 55 million people. Agricultural policies maintain the productivity of the sector, but are ineffective in stemming the associated environmental degradation, biodiversity loss and rural population decline. As in other post-industrial societies, Australia needs to re-define what its agriculture sector represents, environmentally and socially. This will require greater reappraisal of property rights, public and private benefits and legal structures supporting both. More effective alternative policies are needed for large tracts of unproductive farmland where environmental and social decline are endemic. This paper explores alternative options that offer more balanced prospects in the face of current paradoxes, including paying farmers directly for stewardship services, providing better incentives for retiring non-productive areas from agricultural land use, and retiring watersheds, streamlines and other areas of essential environmental function from agricultural production for better biodiversity conservation.
Article Outline
1. Introduction: the current paradox
1.1. The underlying value system
1.2. Australia's contradictory position
1.3. From pioneer to post-industrial in one step
1.4. Current land uses reflect past values
2. Land tenure, use and value
2.1. The plight of irrigation
2.2. The outback, out of sight
2.3. Non-agricultural land uses in rural regions
3. The look of future landscapes
3.1. Relevance of a European viewpoint
3.2. Unprofitable farms, imperilled biota and conservation reserves
3.3. The search for sustainable systems
3.4. Producing more from less
4. Shifting the perspective
4.1. Facing complex reality in the future
4.2. Sustainability needs sensible science and common sense
References

The use of ex-ante modelling tools in European Impact Assessment: What role does land use play?

2009-05-11T00:05:00.001-07:00

Abstract
Impact Assessment was introduced by the European Commission in 2002 in order to make policy development more transparent and improve the ‘quality’ of European policies. Cross-sectoral consultation, broad participation and the quantitative assessment of the impacts of policies are significant elements of this process. This article specifically addresses the role of tools modelling the impact of policies on land use in Impact Assessment. The choice of a specific modelling tool is conceptualised as an action situation interlinked with other action arenas. The article aims to uncover the institutions structuring the action situation. The outcome of the empirical work suggests that two types of Impact Assessments can be distinguished. Impact Assessments either substantively contribute to the specific policy that the Commission proposes or they legitimise policy choices ex post that have already been adopted. The legislative procedure that applies to a specific policy sector, the policy making culture in the DG and the stakes that are at issue seem to influence whether Impact Assessments contribute to policy development, or legitimise it. Furthermore, the article describes the situation in which desk officers choose a modelling tool throughout Impact Assessment. To advance their careers desk officers aim to produce policy proposals which respond to the issues raised by the actors involved in Impact Assessment and specifically in policy development and, later on, adoption. Therefore, desk officers’ preferences are shaped by the community that is involved in policy development and Impact Assessment. The article describes what role modelling tools play in European Impact Assessment procedures and it names the heuristic of criteria which desk officers use to choose a modelling tool. Besides several technical and data problems of modelling land use impact, it seems to be unlikely that land use will become a significant dimension of Impact Assessment and modelling as it is confronted with an unfavourable institutional environment at the European level.
Article Outline
1. Introduction
2. Conceptual approach and methodology
3. Context-action arena
4. Action situation
4.1. Participants and participation
4.2. Impact Assessment community
4.3. Selection criteria for quantitative ex-ante policy assessment tools
4.4. The relevance of land use for Impact Assessment in the European Union
5. Conclusions
Appendix A. Open questions for semi-structured interviews as part of Institutional Analysis of quantitative assessment tool use throughout Impact Assessment
References

Tobacco growers at the crossroads: Towards a comparison of diversification and ecosystem impacts

2009-05-11T00:04:00.005-07:00

Abstract
An international Framework Convention on Tobacco Control has been in force since 2005, also aimed at regulating tobacco farming: FCTC article 17 on diversification, and FCTC article 18 on socio-ecological issues. Relating to the FCTC, information was gained and evaluated from tobacco farmers of growing areas sampled from major world regions (Rio Grande do Sul/Brazil, Tabora/Tanzania, Meinung/Taiwan, and Germany/Europe). A local farming survey was carried out in 2007, using a common data protocol, which covered, among others, questions on area and production development, energy used in curing, workforce, economic livelihood situation, and diversification opportunities. In addition to the survey, secondary (national-scale) statistics, public testimonies and other published data were explored. We analyzed these data using a portfolio approach, which combined statistical analysis, meta-analytical study and descriptive narratives. The projected trend of a global shift of tobacco cultivation into the developing world is confirmed, but also refined. Wood is used in Brazil and Tanzania for curing Virginia green leaf, thus contradicting the projected continuous reduction of this energy source. Child labour remains a major component of family farm tobacco operations in Brazil and Tanzania, while the cost and availability of seasonal labour turns into a bottleneck of production in Germany. More diversification opportunities exist than generally claimed, but no efforts are seen to address poor and vulnerable growers, in particular. German and Taiwanese tobacco growers can reasonably be predicted to discontinue farming in the near future, while tobacco cultivation in Brazil and Tanzania is seen to expand, mainly due to the political economy of low-cost production. Conclusions are drawn with respect to the work of the UN Study Group on Economically Sustainable Alternatives to Tobacco Growing (ESATG), effective since 2007.
Article Outline
Introduction
Material and methods
Description of the databases
Description of the study areas
Brazil
Tanzania
Taiwan
Germany
Results
Area and production development, including varieties
Energy used in curing, including ecosystem effects
Workforce and economic livelihood
Diversification: other crop cultivation, and beyond
Brazil
Tanzania
Taiwan
Germany
Discussion
Area and production development
Environmental implications
Barriers and opportunities for diversification
Theoretical considerations
Conclusions
Acknowledgements
References

An integrated approach for ex-ante evaluation of public policies for sustainable agriculture at landscape level

2009-05-11T00:04:00.003-07:00

Abstract
An integrated methodological framework for ex-ante evaluation and planning of public policies for sustainable agriculture at agro-landscape level is proposed. The components of the framework are to: (1) determine the private, i.e. farmers’, and public benefits associated to agro-landscapes, consisting of an agricultural land-use system, according to its performance for several market and non-market functions. Market forces determine the market benefits and preferences of society the non-market benefits; (2) explore and select potential sustainable agro-landscapes based on the private and public benefits associated with possible land-use alternatives; (3) define efficient public policy mechanisms for improving social net benefit of agro-landscapes.
The framework is illustrated with a case study in a small dairy farming dominated agro-landscape in The Netherlands, with gross margin, landscape quality, nature value and environmental health as the analysed ecosystem functions. Alternative landscapes consisting of hedgerow configurations and grassland management practices were explored, yielding a set of alternatives representing the solution space in terms of change in private and public benefits. Policy mechanisms were defined to move from the current to a desired landscape based on changes in social net benefits. Moreover, the necessity of a modification in the current agri-environmental support was analysed for each landscape. The analysis considered all farmers in the agro-landscape jointly. The results for the case study showed potential prototypes of landscapes and their performance compared to the current landscape. Extension was the most efficient policy mechanism to promote the change to the socially optimum landscape alternative.

Article Outline
Introduction
Methodological framework
Assessment of societal preferences for agricultural non-market functions
Model-based generation and evaluation of land-use alternatives
Generation and multi-criteria evaluation of landscapes: market and non-market net benefits
Calculation of private and public net benefits
Identification of efficient policy instruments for sustainability
Case study
Results
Private and public benefits of alternative landscapes
Land-use alternatives and policies at landscape level
Discussion
Acknowledgements
References

To populate or preserve? Evolving political-demographic and environmental paradigms in Israeli land-use policy

2009-05-11T00:04:00.001-07:00

Abstract
There has been a recent proliferation of national land-use policies that emphasize protecting open space and ecosystem integrity. However, countries grappling with internal political conflict, or that are engaged in military conflicts with neighboring countries, have priorities that focus on control of land in areas where state sovereignty is perceived to be threatened. These two concerns, political-demographic control and environmental protection, create very different paradigms for how to think about open space policy. The objective of this paper is to consider the impact of competing paradigms in land-use policy formulation and implementation—one that encourages sprawl and the other that encourages compact development and the preservation of open space. We use Israel as a case study where both political demography and environmental land-use paradigms are currently influencing policy and planning. We explore the historical evolution of both land-use paradigms and consider how they are currently competing in the formulation and execution of land-use policy decisions. We consider how these distinct priorities are playing out in current discourse and policy implementation, and characterize the past, current and prospective future physical outcomes of policies on the landscape. Our goal is to alert policy makers and land-use scholars of the subtle and contradictory influence of political-demographic land-use priorities with regard to their potential impact on the successful implementation of environmental policies. The Israeli case study is indicative of a diversity of countries that have a history of political-demographic land-use policies, but have also begun to adopt environmentally motivated policies.
Article Outline
Introduction
Case study: Israel
Spatial planning and demographic realities in Palestine/Israel
Political-demographic land-use policy
Environmental land-use policy
Parallel development of political-demographic and environmental land-use policies—a conceptual model
Political-demographic and environmental planning in the Galilee
Political-demographic and environmental planning in the Negev
1948 to 2001
The Negev today—an incomplete paradigm shift?
Discussion
Acknowledgements
References

The effectiveness of the protection of riparian landscapes in Israel

2009-05-11T00:03:00.004-07:00

Abstract
Riparian landscapes are natural habitats of unique ecological, environmental and scenic values, which are highly sensitive to human intervention and impact. Yet, due to their qualities, and especially the presence of water, they are also usually attractive for recreation purposes. This is more so in arid and semi-arid zones like Israel. Nevertheless, in the past, the importance of riparian landscapes in Israel did not receive adequate attention in policy and planning. As a result, over the years they were exposed to various negative impacts, including pollution by industrial and agricultural effluents, diversion of water for agricultural and other purposes, and land use conflicts. Although in recent years, with the growing awareness of their ecological and recreational potential, considerable efforts are being invested in the rehabilitation of deteriorated riparian landscapes, their protection is still deficient.
This article reviews and examines policy tools used for the protection of riparian landscapes in Israel, focusing on legislation, institutional structure and physical planning as they emerge from relevant laws, reports and literature. It reveals, among others, gaps and deficiencies in legislation, institutional dualities along with split authorities both expressing a particularistic approach, and, until recently, lack of relevant designated planning. The article concludes by offering some suggestions for improving the protection of riparian landscapes in Israel, including: integration of existing laws based on a whole watershed approach; reorganization of institutional structure to facilitate a national vision of riparian landscapes rather than the existing particularistic approach; formulation of structured planning procedures to ensure the realization of designated national plans; and promotion of awareness to riparian values at various levels.

Article Outline
Introduction
The importance of riparian landscapes
The rivers in Israel
Protection of riparian landscapes in Israeli legislation
The Water Law
The Drainage Law
The Rivers Authorities Law
Institutional structure
Drainage Authorities
Rivers Authorities
The River Restoration Administration
Physical planning as a protection tool
National planning
The Sharon Plan
National outline plan (NOP) 31
NOP 35
Sectorial NOPs and NOP 34/b/3
Regional planning
Local planning
Discussion
Conclusion
References

Sick building syndrome and perceived indoor environmental quality: A survey of apartment buildings in Hong Kong

2009-05-11T00:03:00.003-07:00

Abstract
The outbreak of a highly communicable disease, SARS, in Asia in 2003 has revealed the health risk of living in a high-density environment. To show the important connection between human health and environmental quality, this study surveys the prevalence of sick building syndrome (SBS) among apartment residents and their evaluation of indoor environmental quality (IEQ). Based on a sample of 748 households living in Hong Kong, two interesting findings are revealed: (1) nasal discomfort was the commonest home-related SBS symptom despite the absence of any central ventilation system in apartment buildings; (2) noise, rather than ventilation, was the major IEQ problem perceived by residents. Our statistical analysis further showed that residents with SBS symptoms were less satisfied with their IEQ than those without. That is, despite a positive evaluation of specific IEQ criteria with respect to the building residents lived in, if they reported feeling SBS related symptoms, the overall IEQ evaluation of their building could still be negative. This perception bias gives rise to a sample selection problem in measuring perceived IEQ, which has implications on housing management practices and the formulation of a healthy housing policy.
Article Outline
Introduction
Literature review
Questionnaire and sample
Analysis and results
Self-reported SBS symptoms
Perceived IEQ
Statistical analysis
Model 1
Model 2
Conclusion
Summary of results
Policy implications
Limitations and further research
Acknowledgements
Appendix. Sample questionnaire (translated from Chinese)
References

Differentiation of rural development driven by industrialization and urbanization in eastern coastal China

2009-05-11T00:03:00.001-07:00

Abstract
With the socio-economic transformation, regional development factors recombination and followed industrial restructuring have changed the rural areas in eastern coastal China deeply. The interaction between the material and non-material elements affecting rural production and lifestyles shaped different rural development types depending on a carrier, which is composed of different industries. Accordingly, this paper makes the definitions of four rural development types, i.e., farming industry dominated rural development type (FIT), industry dominated rural development type (IDT), rural development type focusing on business, tourism and services industries (BTT), and balanced rural development type (BDT), and classifies the rural development types in eastern coastal China. Then, taking the social representation approach and basing on the major factors affecting the long-term rural development and the exertion of the functions of the countryside with regard to society, the assessment indicator system of rurality degree index (RDI) was established to distinguish the rurality degree of different types. The results indicated that, to some extent, the RDI may accurately reflect the status quo of rural development and the exertion of the functions of the countryside with regard to society, and can also reflect the different stage in what the same rural development type in different region stays. The authors argue that the study on the interaction of rural development factors in the process of economic and social transformation and the subsequent rural development model is very important to deeply understand the rural development and to smoothly achieve coordinated and balanced rural–urban development in developing countries, which are experiencing rapid industrialization and urbanization.
Article Outline
Introduction
Rural–urban relationships in China
Definition of China's rural development types
Study area
Materials and methods
Data source and processing
Methods
Results
Discussion and conclusions
Acknowledgements
References

A general equilibrium approach to tourism and welfare: The case of Macao

2009-05-11T00:02:00.006-07:00

Abstract
Macao has been witnessing spectacular economic growth in recent years. The ongoing boom is mainly driven by rapid tourism growth reflected in massive tourist arrivals and foreign capital inflow. Although Macao is praised as an ‘economic wonder’, serious externalities have emerged, raising concerns about the sustainability of the city's long-term development. Using a modified simple general equilibrium model, this paper shows how economic, social, environmental and political externalities accompanying rapid tourism growth may possibly reduce the net welfare of host communities. The paper concludes that comprehensive tourism policies leading to a sustainable development should be developed in a broader social framework.
Article Outline
Introduction
The model
The case of Macao
Data collection and analysis
Findings and discussion
Social–political externalities
Concluding remarks
References

Constructing collaborative processes through experiential learning: Participatory planning in Kaymaklı, Turkey

2009-05-11T00:02:00.005-07:00

Abstract
Prevalent discussions in urban planning focus on collaboration. However, they do not explain the underlying processes that allow collaborative work. This paper argues that experiential learning processes can help construct and maintain collaborative platforms in urban planning. To show this, the paper uses the participatory planning of Kaymaklı, a small agricultural and touristic town in the internationally well-known cultural landscape, the Cappadoccia region. This entails the second stage of a two-year long Participatory Action Research project initiated by a local civil association in collaboration with the Municipality of Kaymaklı. The paper presents how the local capacity for collaboration is built through the development of local knowledge in a practice-based training programme. The attention is particularly directed to the pedagogic design of the training programme, the shared knowledge that came out of it, the affects of the programme on the collaborative capacity of participants, and their future collaborative action.
Article Outline
Introduction
What constitutes learning in order to collaborate?
Growing need for collaboration in Kaymaklı
Being a woman in Kaymaklı
Civil efforts to empower women in Kaymaklı
Organizational structure of the project
Learning model for collaboration
Procedural principles
Content-wise principles
New local knowledge and action revealed
Preparation of the participatory training programme
The realized stakeholder map
The imagined future of the city
Follow-up on the implementation activities
Concluding remarks
References

Determinants of domestic waste input use in urban agriculture lowland systems in Africa: The case of Yaoundé in Cameroon

2009-05-11T00:02:00.003-07:00

Abstract
This paper suggests policy actions for safe urban and peri-urban agriculture and domestic waste recycling in urban lowland areas of Africa, in particular, in lowland areas of the capital of Cameroon, Yaoundé. We identify the explanatory variables of recycling domestic waste and their use in three selected lowland areas. Data were collected between August and September 2005 among 126 farmers. Results show that the factors contributing to the adoption of recycled fresh and decomposed kitchen waste are: vegetable production, the distance between the house and its crop field and the use of livestock waste. The factors contributing to the adoption of recycled livestock wastes are the age of the farmers, the distance between the house and its crop field, the educational level of farmers and land size. Young farmers are more likely to adopt recycled livestock wastes, and short distances between houses and crop fields are more likely to contribute to the adoption of both recycled kitchen waste and recycled livestock wastes. In this context, the implementation of transfer stations for domestic waste, inside or next to lowland areas, appears to be an adequate solution of transport and sanitary constraints faced both by farmers and municipalities in Africa.
Article Outline
Introduction
Data sources
The dichotomic logit model
Variables and descriptive statistics
Empirical model
Results
Conclusions and recommendations
Acknowledgements
References

The continuity and change in mega-urbanization in Indonesia: A survey of Jakarta–Bandung Region (JBR) development

2009-05-11T00:02:00.001-07:00

Abstract
The physical development of the Jakarta Metropolitan Area (JMA) and the Bandung Metropolitan Area (BMA) is characterized by the formation of an urban belt from Jakarta to Bandung of about 200 km, reflecting a growing mega-urban region marked by a mixture of rural and urban activities and blurred rural-urban distinction. This process is continuing at an even with faster rate than in the period from the 1980s to the mid-1990s. In fact, the JMA and the BMA are both experiencing transformation from single-core to multi-core cities. In the past three decades the development of socioeconomic activities has resulted in several environmental problems. The JBR also faces problems of uncontrolled land conversion. New town developments have reinforced spatial segregation by life style and income status while industrial estates are also growing in the region. There is a tendency of local governments in the JBR to try to exploit local resources excessively. The JBR is a functional region that should be managed as an inseparable region through an integrated spatial development plan. Institutional development is now critical to ensure the sustainability of the JBR.
Article Outline
Introduction
Mega-urbanization in Asia
Economic crises
Recent socioeconomic and physical development
Urban population
Land conversion
New town, industrial estate and road development
Early reform and decentralization era
Concluding remarks
Acknowledgements
References

Factors affecting compliance with residential standards in the city of Old Salt, Jordan

2009-05-11T00:01:00.003-07:00

Abstract
The aim of this paper is to examine the factors which impact on the extent to which urban housing complies with residential standards in the city of Old Salt based in Jordan. The research found that the level of compliance with residential standards is quite low and can vary from one standard to another and from one house to another due to differences in the socio-economic characteristics among people. The findings of multiple regression analysis reveal that there is a good level of public awareness of residential standards, but this does not result in complete compliance with residential standards. Factors, such as household income per month, household size, finance facilities, municipal administration culture, monitoring, enforcement and the uncertainty of residential standards have a significant impact on the extent of compliance with planning standards. Suggestions for improved urban planning practices which address these issues are summarised in the paper and include reassessed current residential standards through comprehensive legal frameworks, linking residential standards with urban design approaches, changing planning practices, developing information systems to produce effective monitoring systems of construction processes and enforcement mechanisms, the development of local staff including planners, designers and environmental engineers, supported partnerships between private and public sectors, and the use of participatory planning and citizen involvement.
Article Outline
Introduction
Residential building standards in Old Salt
Residential zones
Land subdivisions
Setbacks
Plot frontage
Research framework
Compliance with residential standards
Socio-economic factors
Administrative practices
The uncertainty of residential standards
Methodology
Results and discussion
The degree of compliance with residential standards
Findings from testing the overall hypotheses and interviews
Implications
References

Prevalence of intestinal helminth eggs on vegetables grown in wastewater-irrigated areas of Titagarh, West Bengal, India

2009-05-11T00:01:00.001-07:00

Abstract
A total of 46 wastewater samples (untreated: 24 and treated: 22), 35 soil samples and 172 vegetable samples were collected from the wastewater-irrigated area of Titagarh to assess its contamination level with intestinal helminth. 83.3% of raw wastewater, 68.2% of treated wastewater, 68.6% of soil and 44.2% of vegetables in the study area were found to be positive for helminth ova. Vegetables grown in this area were found positive for Ascaris lumbricoides (36%), Trichuris trichiura (1.7%) and hookworms (6.4%). A. lumbricoides was the most predominant species observed in all the samples. Of all the vegetables examined, Pudina was most commonly contaminated followed by Lettuce, Spinach, Coriander, Celery and Parsley. High percentage of viable-stage intestinal helminth egg positive vegetable samples grown in the wastewater-irrigated study area may pose serious public health hazards.
Article Outline
1. Introduction
2. Materials and methods
2.1. Study area
2.2. Detection of helminth eggs in vegetables
2.3. Detection of helminth eggs in irrigation water and soil
2.4. Analysis of data
3. Results
4. Discussions
Acknowledgements
References

Bacterial quality of raw milk investigated by Escherichia coli and isolates analysis for specific virulence-gene markers

2009-05-10T23:59:00.001-07:00

Abstract
The bacterial quality and safety of raw milk sources in Taif region (Western Saudi Arabia) were analyzed for the natural contamination of fecal coliform and Escherichia coli by standard most probable number method. The E. coli isolates were identified to species identity using API 20E and screened for markers of STEC (Stx1, Stx2), ETEC (ST, LT), (EaeA) and ExPEC (CNF1, CNF2, SfaS, PapA, CdtB, IutA, FyuA, TraT) using PCR assays. Thirty-three E. coli strains were recovered from raw milk sample sources, which were contaminated by fecal coliform. None of the investigated isolates reacted positively with the PapA, SfaS and CdtB, ST and LT-specific primers. Markers of STEC and EPEC were each detected in three strains. NTEC was detected in four strains. The most frequent virulence markers were TraT (17 strains), IutA (11 strains) and FyuA (8 strains). Results suggested a possibility of potential public health threat of E. coli originating from raw milk sources.
Article Outline
1. Introduction
2. Materials and methods
2.1. Sample collection
2.2. Isolation and identification of coliforms
2.3. DNA isolation
3. Polymerase chain reaction (PCR)
4. Results
4.1. Fecal coliform contamination
4.2. Polymerase chain reaction
5. Discussion
References

Hygienic quality of head lettuce: Effects of organic and mineral fertilizers

2009-05-10T23:58:00.006-07:00

Abstract
The hygienic quality of head lettuce (Lactuca sativa L.) was investigated after different fertilizer treatments (fresh farmyard manure, composted farmyard manure, stinging nettle extract and calcium ammonium nitrate) in a 2-year field experiment with two trials per year, respectively. For assessment of the hygienic quality the total aerobic bacterial counts, Enterobacteriaceae, coliform bacteria, Escherichia coli and Salmonella were investigated in soil, fertilizer and lettuce samples. Plants were washed with running tap water before analysis. The total aerobic bacterial count, as well as the levels of Enterobacteriaceae and coliform bacteria tended to be slightly higher (not significant) after organic compared to mineral fertilization. No Salmonella was detected in any soil, fertilizer or lettuce sample, while E. coli was randomly detected in low concentrations independent from fertilizer treatment. No higher risk of bacterial contamination due to the use of organic fertilizers was indicated.
Article Outline
1. Introduction
2. Material and methods
2.1. Experimental site
2.2. Field experiments
2.3. Fertilization
2.4. Sampling and analysis
2.5. Statistical analysis
3. Results
3.1. Enteric bacteria in fertilizers
3.2. Enteric bacteria in fertilized soil
3.3. Hygienic quality of lettuce
4. Discussion
Acknowledgements
References

Local air pollutant emission reduction and ancillary carbon benefits of SO2 control policies: Application of AIM/CGE model to China

2009-05-10T23:58:00.005-07:00

Abstract
While a great deal of literature has been published in recent years on the ancillary benefits of greenhouse gas mitigation (e.g., reductions in local air pollution), less attention has been focused on the climate benefits of local air pollution strategies themselves. Local air pollution is, however, a more immediate issue now faced by developing countries. This study assesses the impacts on local air pollutant emission reduction and ancillary CO2 emission reduction of SO2 control policies in China, such as a sulphur tax, SO2 total emissions control (TEC), and improvement of energy efficiency, based on the Asia-Pacific Integrated Model (AIM)/Computable General Equilibrium (CGE) country model. The simulation period is from 1997 to 2020. Major conclusions include the following: an SO2 emission cap will help to control SO2 emissions, but will result in a large GDP loss; the role of a SO2 emission tax at the present level is very limited; and an ancillary carbon reduction benefit can be achieved through the introduction of SO2 control policies in China.
Article Outline
1. Introduction
1.1. Acid rain and SO2 emission status in China
1.2. Main air pollution control policies in China
1.3. Objectives of this study
2. Model descriptions
2.1. Within-period specification
2.1.1. Production
2.1.2. Consumption
2.1.3. Government
2.1.4. Investment (fixed capital formation)
2.1.5. International trade
2.1.6. Environment
2.2. Between-period specification
3. Base year data
3.1. Input and output data for economic activity
3.2. Investment data
3.3. Energy data
3.4. Summary of base year data
4. Scenario description
4.1. Basic scenario dataset
4.2. Policy simulation
5. Results
5.1. SO2 emissions
5.2. GDP change
5.3. Energy consumption
5.4. NOx emissions and CO2 emissions
5.5. Output of production sectors
5.6. Sensitivity analysis
6. Main findings and conclusions
Acknowledgements
References

Revising the OWA operator for multi criteria decision making problems under uncertainty

2009-05-10T23:58:00.003-07:00

Abstract
Multi criteria decision making (MCDM) problems are usually under uncertainty. One of these uncertain parameters is the decision maker (DM)’s degree of optimism, which has an important effect on the results. Fuzzy linguistic quantifiers are used to obtain the assessments of this parameter from DM and then, because of its uncertainty it is assumed to have stochastic nature. A new approach, entitled FSROWA, is introduced to combine the Fuzzy and Stochastic features into a Revised OWA operator.
If the DM is not aware of the risk in decision, then the decision objective is to maximize the expected combined goodness measure. If the DM cares only about the risk, then minimizing the variance of the combined goodness measure is his/her objective. The results of the FSROWA provide the expected value and the variance of the combined goodness measure for each alternative. In order to combine these two attributes a composite goodness measure is introduced. This measure gives more robust decision outcomes. The theoretical results are illustrated in a watershed management problem.

Article Outline
1. Introduction
1.1. Stochastic nature
1.2. Fuzzy nature
1.3. Fuzzy-stochastic nature
2. The OWA operator
3. New method: FSROWA
3.1. Revised OWA by using fuzzy linguistic quantifiers
3.2. Stochastic simulation for the degree of optimism
3.3. Composite goodness measure
4. Case study
4.1. Special assumptions
5. Conclusion
References

A decomposition approach for the probabilistic maximal covering location-allocation problem

2009-05-10T23:58:00.001-07:00

Abstract
The maximal covering location problem (MCLP) maximizes the population that has a facility within a maximum travel distance or time. Numerous extensions have been proposed to enhance its applicability, like the probabilistic model for the maximum covering location-allocation with a constraint in waiting time or queue length for congested systems, with one or more servers per service center. This paper presents a solution procedure for that probabilistic model, considering one server per center, using a column generation and covering graph approaches. The computational tests report interesting results for network instances up to 818 vertices. The column generation results are competitive solving the instances in reasonable computational times, reaching optimality for some and providing good bounds for the difficult instances.
Article Outline
1. Introduction
2. QM-CLAM
3. The decomposition approach to the QM-CLAM
3.1. The covering graph
3.2. QM-CLAM decomposition
4. DW decomposition and column generation approach for the QM-CLAM
5. Computational results
6. Conclusions
Acknowledgements
References

Sensory pollution from bag-type fiberglass ventilation filters: Conventional filter compared with filters containing various amounts of activated carb

2009-05-10T23:57:00.005-07:00

Abstract
As ventilation filters accumulate particles removed from the airstream, they become emitters of sensory pollutants that degrade indoor air quality. Previously we demonstrated that an F7 bag-type filter that incorporates activated carbon (a “combination filter”) reduces this adverse effect compared to an equivalent filter without carbon. The aim of the present study was to examine how the amount of activated carbon (AC) used in combination filters affects their ability to remove both sensory offending pollutants and ozone. A panel evaluated the air downstream of four different filters after each had continuously filtered outdoor suburban air over a period of 6 months. Interim assessments (mid-term evaluation) were performed after 3 months. During both assessments, four unused filters, identical in type to the loaded filters, were also evaluated. The evaluated filters included a conventional F7 fiberglass filter and three modifications of a bag-type fiberglass combination filter: the “Heavy” corresponded to a commercially available filter containing 400 g of carbon per square meter of filter area, the “Medium” contained half as much carbon (200 g/m2), and the “Light” contained a quarter as much carbon (100 g/m2). Each filter was weighed at the beginning of the soiling period and after 3 and 6 months of service. Additionally, up- and down-stream ozone concentrations and filter pressure drops were measured monthly. Following 6 months of service, the air downstream of each of the combination filters was judged to be significantly better than the air downstream of the 6-month-old F7 filter, and was comparable to that from an unused F7 filter. Additionally, the combination filters removed more ozone from the air than the F7 filter, with their respective fractional removal efficiencies roughly scaling with their carbon content.
Article Outline
1. Introduction
2. Methods
3. Results and discussion
3.1. Statistical analyses
3.2. Sensory pollution
3.3. Ozone removal
3.4. Weight change and pressure drop
3.5. Limitations of the study
4. Conclusions and implications
Acknowledgements
References

Investigation of indoor chemical pollutants and perceived odor in an area with complaints of unpleasant odors

2009-05-10T23:57:00.003-07:00

Abstract
An uncomfortable smell was reported by employees of an IT office (information technological office) in a medical center. This problem started two years ago when the office was refurbished. The objectives of this study are to characterize the indoor air quality of this complaint area in terms of chemical pollutants and odor characteristics, and identify possible sources of this foul smell. Carbonyl chemicals and volatile organic compounds (VOCs) were investigated in this study, since these two groups are associated with odors and health effects. Additionally, the odor was evaluated by odor assessors (non-smokers) who recorded odor characters that appeared in offices. By comparing chemical measurements between complaint and non-complaint areas, calculating odor indices, and correlating odor and chemical measurements, we got results showing that a higher correlation coefficient is found between odor presence frequencies and VOC concentrations. Further investigating found nonanal and decanal are possible chemicals for malodors. The concentration levels of these two chemicals in the complaint area are higher than those in the non-complaint areas and exceeding odor thresholds. Possible sources of these long-chain aldehydes are formed during the oxidation degradations of fatty acids like linoleic acid, linolenic acid and oleic acid which are ingredients for many building products like linoleum and surface coating. In order to mitigate this malodor problem, extra and effective ventilation flow rate should be provided to reduce the concentrations of odorous chemicals and the precursors for these odorous chemicals.
Article Outline
1. Introduction
2. Materials and methods
2.1. Office description
2.2. Sampling strategy
2.3. Sample analysis
2.4. Statistical analysis
3. Results
3.1. Characteristics of temperature, humidity, and CO2
3.2. Characteristics of carbonyl measurements
3.3. Characteristics of VOC measurements
3.4. Odor investigation
3.5. Correlation and comparison between odor and chemical measurements
4. Discussion
4.1. Carbonyl and VOC measurement comparison between this study and other indoor studies
4.2. Limitations, applications, and suggestions
5. Conclusions
Acknowledgements
References

Deposition of aerosol particles on rough surfaces inside a test chamber

2009-05-10T23:57:00.001-07:00

Abstract
We investigated the deposition rate of aerosol particles (diameter between 0.03 and 5 μm) on rough surfaces of wallpapers, wall-plasters, and two types of carpets inside a test chamber. Compared to a smooth aluminum surface, the deposition rate of aerosol particles on the tested surfaces was up to 20 times depending on the surface roughness, mixing intensity, and particle size. A rough surface with a dimensionless surface roughness height k+ < 0.06 can be treated as a hydraulically smooth. The estimated deposition rates in this study and those predicted by a deposition model, which incorporates surface roughness, were in good agreement for coarse mode particles (diameter > 1 μm) when k+ < 1.04 and for ultrafine particles (diameter < 0.1 μm) when k+ < 0.48. The agreement between the model prediction and our estimation was better for coarse mode particles than for ultrafine particles. Deposition of aerosol particles, especially fine particles, needs more empirical investigations aiming at improving the existing models.
Article Outline
1. Introduction
2. Experimental setup and measurement
2.1. Wall materials and surface roughness
2.2. Aerosol particle generation and measurement
2.3. Estimation and prediction of the deposition rate
2.3.1. Semi-empirical estimation
2.3.2. Prediction with a deposition model
3. Results and discussion
3.1. Deposition on wallpapers
3.2. Deposition on wall-plasters
3.3. Deposition on carpets
4. Summary and conclusions
Acknowledgements
References

Indoor/outdoor relationship of fine particles less than 2.5 μm (PM2.5) in residential homes locations in central Indian region

2009-05-10T23:56:00.005-07:00

Abstract
The high levels in developing countries and the apparent scale of its impact on the global burden of disease underline the importance of particulate as an environmental health risk and the consequence need for monitoring them particularly in indoor microenvironment. PM2.5 μm, 1.0 μm, 0.5 μm and 0.25 μm were measured inside and outside 14 residential homes located in different microenvironment during a six-month period (October 2007–March 2008) in Agra located in the central region of India. Particulate mass concentrations were measured using Grimm aerosol spectrometer for 24 h inside and outside the homes located in roadside, rural and urban area, along with the field survey study done in the same region. The indoor average concentrations recorded for PM2.5, PM1.0, PM0.5 and PM0.25 were maximum for the rural homes (173.03 μgm−3, 133.26 μgm−3, 96.02 μgm−3, 8.56 μgm−3) followed by roadside homes (137.93 μgm−3, 117.09 μgm−3, 68.17 μgm−3, 8.55 μgm−3) and then by urban homes (135.55 μgm−3, 102.92 μgm−3, 38.38 μgm−3, 6.35 μgm−3). The average I/O ratios for PM2.5, PM1.0, PM0.5 and PM0.25 in roadside and rural areas were close to or above 1.00 and less than 1.00 for urban areas. The I/O ratios obtained were linked to the indoor activities using occupant's diary entries. The positive values of correlation coefficient (r) also indicated the indoor concentrations of particulate matter were correlated with the corresponding outdoor concentrations.
Article Outline
1. Introduction
2. Methods
2.1. Site description
2.2. Indoor and outdoor particulate mass concentration measurements
2.3. Questionnaire survey
3. Result and discussion
3.1. Indoor/outdoor particulate concentration
3.2. Indoor/outdoor ratios, correlations and source implications
3.3. Questionnaire survey
3.3.1. Health effects
3.3.2. The distribution of risk factors and awareness
4. Conclusion
Acknowledgements
References

Thermal perception, adaptation and attendance in a public square in hot and humid regions

2009-05-10T23:56:00.003-07:00

Abstract
Highly relevant to an individual's thermal perception, the thermal environment in outdoor public spaces impacts the use of such spaces. Thermal adaptation, which involves physiological, psychological and behavioral factors, also plays an important role in assessment of thermal environments by users. Given that these issues have rarely been addressed for outdoor environments in hot and humid regions, this study examines user thermal comfort in a public square in Taiwan. Physical measurements were taken and a questionnaire survey was used to assess the thermal comfort of subjects. The number of people visiting the square was also counted. Analytical results indicate that the thermal comfort range and neutral temperature of subjects was higher than those of people in a temperate region. Additionally, local subjects preferred a cool temperature and weak sunlight, and adapted to thermal environments by seeking shelter outdoors. Analytical results confirm the existence of thermal adaptation and illustrate the characteristics of, and variances in, thermal adaptation. During the cool season, the number of people visiting the square increased as the thermal index value increased. However, the number of people frequenting the square decreased as the thermal index increased during the hot season. These experimental results were compared with those for temperate regions, indicating that the human energy balance model cannot fully explain the influence of climate on use of public spaces; that is, psychological and behavioral factors also play important roles in outdoor thermal comfort. Study findings also elucidate design of outdoor public spaces in hot and humid regions.
Article Outline
1. Introduction
2. Method
2.1. Study area
2.2. Physical measurements
2.3. Thermal comfort indices
2.4. Questionnaire survey
2.5. Observations of attendance in the square
3. Preliminary results of subject thermal comfort
3.1. Thermal sensation
3.2. Thermal acceptable range
4. Evidence of thermal adaptation
4.1. Experience factor for psychological adaptation
4.2. Expectation factor for psychological adaptation
4.2.1. Expectations for thermal environmental factors
4.2.2. Preferred temperature
4.3. Perceived control factors for psychological adaptation
4.4. Behavioral adaptation
5. Thermal environment and square use
5.1. Selection of observations
5.2. Correlation between thermal environment and number of people
6. Discussion
6.1. Thermal adaptation in hot and humid regions
6.2. Thermal environment and use of public spaces in different countries
6.3. Design strategy for outdoor public spaces in hot and humid regions
7. Conclusions
Acknowledgements
References

Performance of Euro III common rail heavy duty diesel engine fueled with Gas to Liquid

2009-05-10T23:56:00.001-07:00

Abstract
The effect of synthetic diesel fuel made from natural gas (Gas to Liquid, GTL) on the engine performances (such as power, efficiency and emission) was carried out on one Euro III common rail (CR) heavy duty (HD) diesel engine without any modification. The results showed that the engine fueled with GTL had some variations compared with the one fueled with petroleum-based low sulfur diesel fuel (sulfur content less 50 ppm). The maximum torque and power were decreased by 1.3% and 1.9%, respectively. The specific fuel consumption increased in volume but had no change in mass. Under the load characteristics, the NOx, CO and THC were reduced by 13%, 55% and 55%, respectively. During the ESC cycle test, the NOx, CO, THC and PM were reduced by 5.2%, 19.3%, 19.8% and 33%, respectively.
Article Outline
1. Introduction
2. Fuel and experimental apparatus
2.1. Fuel
2.2. Experimental apparatus
2.2.1. Engine
2.2.2. Dynamometer and emissions equipments
2.3. Study process
3. Engine performance
3.1. Engine power output
3.2. Fuel economy
3.3. Emission characteristics
3.3.1. NOx
3.3.2. CO
3.3.3. THC
4. ESC emission results
4.1. Selection of ESC operating points
4.2. Emission results
5. Conclusions
Acknowledgements
References

Study of the effect of contraction of cross-sectional area on flow energy merger in hybrid pneumatic power system

2009-05-10T23:55:00.001-07:00

Abstract
This paper presents simulation study on the effects of the cross-sectional area at the merging region and high pressure compressed airflow rate on the flow energy merger, and their optimum adjustments for the change in the compressed air pressure (Pair) in the hybrid pneumatic power system (HPPS). The simulation of energy mixing and merging processes was performed for an innovative energy merger pipe in which the open angle (A) of the air storage tank’s throttle valve and the contraction of the cross-sectional area (CSA) at the merging region of the energy merger pipe can be adjusted for changes in Pair. The simulations were carried out using computational fluid dynamics (CFD). The results showed that the exhaust-gas recycling efficiency and the merger flow energy are significantly dependent on the optimal adjustments of A and CSA for the change in Pair. The optimal conditions for higher exhaust-gas recycling efficiency and the best energy merging process can be achieved at A of around 25–100% and a CSA of around 5–40% for a full range of Pair. Under these conditions, the exhaust-gas recycling efficiency reached approximately 80–88%. Therefore, a vehicle equipped with an HPPS can achieve a level of efficiency that is approximately 40% higher than that of conventional vehicles.
Article Outline
1. Introduction
2. Study methodology
3. Numerical model
3.1. Physical and mathematical model
3.2. Validation study of model
3.2.1. Experimental description
3.2.2. Simulation
3.2.2.1. Model design
3.2.2.2. Boundary conditions
3.2.3. Validation of model
3.2.3.1. Static pressure
3.2.3.2. Temperature
4. Results and discussion
4.1. Effect of high pressure compressed airflow rate on merging process
4.2. Effect of CSA on merger flow energy
5. Conclusions
References

Thermoeconomic impact on combined cycle performance of advanced blade cooling systems

2009-05-10T23:53:00.004-07:00

Abstract
In this work the thermoeconomic features of two different combined cycles using air “open loop” and steam “closed loop” cooled gas turbines are presented and compared in depth. In order to properly estimate both thermodynamic and thermoeconomic performance of the different combined cycles an analytical model of the blade cooling system has been developed in details and outlined in the paper. Internal Thermoeconomic functional analysis is not performed here, as only economic results are shown and discussed. The blade cooling detailed model, originally developed by TPG researchers, has been integrated into the web based modular code WTEMP, already validated for GT based cycles, developed in the last ten years by TPG. It is shown that the closed loop blade cooling configuration has the greatest potential in terms of thermodynamic efficiency and economic competitivity in the mid-term.
Article Outline
Nomenclature
1. Introduction
2. Method of calculation
3. The internal Stanton number
4. The external Stanton number
5. Development of open loop and closed loop combined cycles
6. WTEMP tool
7. Exergy analysis
8. Thermoeconomic and investment analysis
9. Conclusions
Acknowledgements
References

Biodiesel production from inedible animal tallow and an experimental investigation of its use as alternative fuel in a direct injection diesel engine

2009-05-10T23:53:00.003-07:00

Abstract
In this study, a substitute fuel for diesel engines was produced from inedible animal tallow and its usability was investigated as pure biodiesel and its blends with petroleum diesel fuel in a diesel engine. Tallow methyl ester as biodiesel fuel was prepared by base-catalyzed transesterification of the fat with methanol in the presence of NaOH as catalyst. Fuel properties of methyl ester, diesel fuel and blends of them (5%, 20% and 50% by volume) were determined. Viscosity and density of fatty acid methyl ester have been found to meet ASTM D6751 and EN 14214 specifications. Viscosity and density of tallow methyl esters are found to be very close to that of diesel. The calorific value of biodiesel is found to be slightly lower than that of diesel. An experimental study was carried out in order to investigate of its usability as alternative fuel of tallow methyl ester in a direct injection diesel engine. It was observed that the addition of biodiesel to the diesel fuel decreases the effective efficiency of engine and increases the specific fuel consumption. This is due to the lower heating value of biodiesel compared to diesel fuel. However, the effective engine power was comparable by biodiesel compared with diesel fuel. Emissions of carbon monoxide (CO), oxides of nitrogen (NOx), sulphur dioxide (SO2) and smoke opacity were reduced around 15%, 38.5%, 72.7% and 56.8%, respectively, in case of tallow methyl esters (B100) compared to diesel fuel. Besides, the lowest CO, NOx emissions and the highest exhaust temperature were obtained for B20 among all other fuels. The reductions in exhaust emissions made tallow methyl esters and its blends, especially B20 a suitable alternative fuel for diesel and thus could help in controlling air pollution. Based on this study, animal tallow methyl esters and its blends with petroleum diesel fuel can be used a substitute for diesel in direct injection diesel engines without any engine modification.
Article Outline
1. Introduction
2. Material and experimental procedure
2.1. Transesterification of animal tallow and the properties of the fuels
2.2. Tests of engine performance and emissions
3. Results and discussion
3.1. Engine performance
3.2. Exhaust emissions
4. Conclusions
Acknowledgements
References

Global and local emission impact assessment of distributed cogeneration systems with partial-load models

2009-05-10T23:53:00.001-07:00

Abstract
Small-scale distributed cogeneration technologies represent a key resource to increase generation efficiency and reduce greenhouse gas emissions with respect to conventional separate production means. However, the diffusion of distributed cogeneration within urban areas, where air quality standards are quite stringent, brings about environmental concerns on a local level. In addition, partial-load emission worsening is often overlooked, which could lead to biased evaluations of the energy system environmental performance.
In this paper, a comprehensive emission assessment framework suitable for addressing distributed cogeneration systems is formulated. Local and global emission impact models are presented to identify upper and lower boundary values of the environmental pressure from pollutants that would be emitted from reference technologies, to be compared to the actual emissions from distributed cogeneration. This provides synthetic information on the relative environmental impact from small-scale CHP sources, useful for general indicative and non-site-specific studies. The emission models are formulated according to an electrical output-based emission factor approach, through which off-design operation and relevant performance are easily accounted for. In particular, in order to address the issues that could arise under off-design operation, an equivalent load model is incorporated within the proposed framework, by exploiting the duration curve of the cogenerator loading and the emissions associated to each loading level. In this way, it is possible to quantify the contribution to the emissions from cogeneration systems that might operate at partial loads for a significant portion of their operation time, as for instance in load-tracking applications.

Suitability of the proposed methodology is discussed with respect to hazardous air pollutants such as NOx and CO, as well as to greenhouse gases such as CO2. Two case study applications based on the emission data of real microturbines are illustrated in order to highlight the effectiveness of the proposed assessment techniques. The numerical results exemplify the emission impact of distributed cogeneration systems operating under general and realistic loading conditions with respect to average and state-of-the-art conventional technologies.

Article Outline
Nomenclature
1. Introduction
2. Cogeneration energy efficiency performance and emission characterization
2.1. Cogeneration energy efficiency performance
2.2. Cogeneration emission factor models
3. Cogeneration emission assessment models
3.1. Global and local emissions
3.2. Models for global emission assessment
3.2.1. The CO2 emission reduction (CO2ER) indicator
3.3. Models for local emission assessment
3.4. Discussion on the emission assessment models
3.5. Reference models for the conventional separate production of heat and electricity
4. The equivalent load approach
4.1. Generalities on off-design emissions
4.2. Formulation of the equivalent load approach
4.3. Utilization of the equivalent load approach
5. Case study applications
5.1. Case 1: 30-kWe MT
5.1.1. Description of the equipment
5.1.2. Partial-load characteristics and CO2 emission assessment
5.1.3. Partial-load NOx and CO emission assessment
5.1.4. Determination of the equivalent load
5.1.5. Results of the integrated emission assessment for different partial-load operational scenarios
5.2. Case 2: 60-kWe MT
5.2.1. Equipment characteristics and CO2 emission assessment
5.2.2. Partial-load NOx and CO emission assessment
5.2.3. Results of the integrated emission assessment through the equivalent load approach
5.3. Comments on the numerical results
6. Conclusion
Acknowledgements
References

Conceptual design and system analysis of a poly-generation system for power and olefin production from natural gas

2009-05-10T23:52:00.002-07:00

Abstract
In this paper, a novel poly-generation system for olefin and power production from natural gas is proposed, which integrates hydrocarbon production and the combined cycle power generation. Economic and technological evaluation based on the internal rate of return (IRR) and exergy efficiency is performed. The energy integration results in the proposed poly-generation system for simultaneous production of chemical products (ethylene and propylene) and electricity being more thermodynamically efficient and economically viable than single purpose power generation and chemical products production plants. IRR and exergy efficiency of the proposed poly-generation system are higher than that of natural gas methanol to olefin (NGMTO) system, 18.9% and 49.9%, respectively. The biggest exergy destruction segments, their causes, and possible measures for improvement are investigated simulation and thermodynamic analysis. To analyze the effect of unreacted syngas recycle on the exergy efficiency and economic gains from the proposed poly-generation system, its thermoeconomic optimization model is built by combining economic with thermodynamic analysis. Optimization analysis shows that when 78% of the unreacted syngas is recycled back to the reactor in the methanol synthesization process, the thermoeconomic performance of the poly-generation system is at its optimum.
Article Outline
Nomenclature
1. Introduction
2. The system – a combined olefin with power generation
3. Flowsheet simulation and exergy calculation in the poly-generation system
3.1. Flowsheet simulation
3.2. Exergy calculation
4. Evaluation of the poly-generation system
4.1. Economic analysis of the proposed poly-generation system
4.2. Exergy analysis of the proposed poly-generation system
5. Thermoeconomic optimization of poly-generation system
6. Conclusions
Acknowledgements
References

The analysis of security cost for different energy sources

2009-05-10T23:52:00.001-07:00

Abstract
Global concerns for the security of energy have steadily been on the increase and are expected to become a major issue over the next few decades. Urgent policy response is thus essential. However, little attempt has been made at defining both energy security and energy metrics. In this study, we provide such metrics and apply them to four major energy sources in the Korean electricity market: coal, oil, liquefied natural gas, and nuclear. In our approach, we measure the cost of energy security in terms of supply disruption and price volatility, and we consider the degree of concentration in energy supply and demand using the Hirschman–Herfindahl index (HHI). Due to its balanced fuel supply and demand, relatively stable price, and high abundance, we find nuclear energy to be the most competitive energy source in terms of energy security in the Korean electricity market. LNG, on the other hand, was found to have the highest cost in term of energy security due to its high concentration in supply and demand, and its high price volatility. In addition, in terms of cost, we find that economic security dominates supply security, and as such, it is the main factor in the total security cost. Within the confines of concern for global energy security, our study both broadens our understanding of energy security and enables a strategic approach in the portfolio management of energy consumption.
Article Outline
1. Introduction
2. Energy policy in Korea
3. Cost of energy security
3.1. Definition of energy security
3.2. Climate change mitigation effect
3.3. Cost of supply security
3.4. Cost of economic security
4. Results and discussion
4.1. Cost of supply security
4.2. Cost of economic security
4.3. Security cost of energy
5. Conclusions
References

Are global warming and economic growth compatible? Evidence from five OPEC countries?

2009-05-10T23:51:00.004-07:00

Abstract
In this paper, we investigate the relationship between carbon emissions, income, energy and total employment in selected OPEC countries for the period of 1971–2002. We mainly focus on the link between energy use and income. Employing the autoregressive distributed lag (ARDL) approach, we find that there is a cointegrating relationship between the variables in Saudi Arabia only. The long run forcing variables for income are determined to be employment and energy for Saudi Arabia. In Indonesia, Algeria, Nigeria, and Venezuela, there is no cointegration between income and energy. Secondly we question the long run Granger causality between carbon emissions, energy use, and income. Our results suggest that none of the countries need to sacrifice economic growth to decrease their emission levels. Indonesia and Nigeria may contribute to emissions reduction via energy conservation without negative long run effects on economic growth.
Article Outline
1. Introduction
2. Trends in OPEC countries
3. Data
4. The relationship between income and energy
5. The relationship between CO2, energy use, and income
6. Conclusions and policy implications
References

Safety of vegetables and the use of pesticides by farmers in China: Evidence from Zhejiang province

2009-05-10T23:51:00.003-07:00

Abstract
In China there are great challenges to ensure the safety of vegetables, as highly toxic pesticides, which are more than likely to cause high pesticide residues in vegetables [Zhang, Y., Ma, J., Kong, X., & Zhu, Y. (2004). Factors that affect farmers’ adoption of non-pollution and green pesticides: Empirical analysis based on data from 15 countries (cities) in Shanxi, Shaanxi and Shandong province. Chinese Rural Economy, 1, 41–49], are still used in the production of vegetables by vegetable farmers. Based on a survey of 507 vegetable farmers from Zhejiang Province, this study attempted to identify and control the vegetable farmers who were at risk of spraying highly toxic pesticides onto vegetables in China. We found that farmers who were older and less educated and unspecialized vegetable farmers were more likely to use highly toxic pesticides. Our statistical results also indicated that vegetable farmers who received less training and selected handlers as their marketing channel had a tendency to apply highly toxic pesticides, whereas cooperative members were less likely to use these pesticides. Finally, vegetable farmers who had a poor understanding of vegetable safety issues were more likely to use highly toxic pesticides. Policy implications to control the use of highly toxic pesticides and ensure the safety of vegetables in China are discussed.
Article Outline
1. Introduction
2. Method
3. Results and discussion
3.1. Demographic analysis
3.1.1. Age
3.1.2. Education level
3.1.3. Planting area
3.1.4. Household size
3.1.5. Professional years
3.1.6. Cooperative membership
3.1.7. Training received
3.2. Pesticides used
3.3. Perceptions on vegetable safety issues
3.4. Identification of farmers at risk of using highly toxic pesticides
4. Conclusion and implications
Acknowledgements
References

Sensitivity analysis of the combined travel demand model with applications

2009-05-10T23:51:00.001-07:00

Abstract
The conventional sequential four-step procedure of travel demand forecasting has been widely adopted by practitioners. However, it suffers from inconsistent consideration of travel times and congestion effects in various steps of the procedure. A combined travel demand model overcomes the problems associated with the sequential four-step procedure by integrating travel-destination-mode-route choice together. In this paper, a standard sensitivity analysis for non-linear programming is employed for conducting the sensitivity analysis of the combined travel demand model. Explicit expressions of the derivatives of model variables with respect to perturbations of input variables and parameters of the combined travel demand model are developed. These derivatives could be used to assess changes in solution variables and various system performance measures when the network characteristics are changed slightly. To gain insight into the usefulness of the sensitivity expressions, five applications, such as identification of critical parameters, paradox analysis, access control, destination choice, and error and uncertainty analysis, are presented with numerical results.
Article Outline
1. Introduction
2. Combined travel demand model
2.1. Notation
2.2. Structure of traveler choice process
2.3. Formulation
3. Sensitivity analysis
3.1. Non-linear programming sensitivity analysis
3.2. Sensitivity analysis of CTDM
4. Numerical examples
4.1. Network and sensitivity analysis
4.2. Applications of sensitivity analysis
4.2.1. Critical Parameters
4.2.2. Paradox analysis
4.2.3. Access control
4.2.4. Destination choice analysis
4.2.5. Error and uncertainty analysis
5. Conclusions
Acknowledgements
References

Capacitated dynamic lot sizing problems in closed-loop supply chain

2009-05-10T23:50:00.005-07:00

Abstract
In this paper, we address the capacitated dynamic lot sizing problem arising in closed-loop supply chain where returned products are collected from customers. These returned products can either be disposed or be remanufactured to be sold as new ones again; hence the market demands can be satisfied by either newly produced products or remanufactured ones. The capacities of production, disposal and remanufacturing are limited, and backlogging is not allowed. A general model of this problem is formulated, and several useful properties of the problem are characterized when cost functions are concave. Moreover, this problem is analyzed and solved to optimality using dynamic programming algorithms under different scenarios. It is shown that the problem with only disposal or remanufacturing can be converted into a traditional capacitated lot sizing problem and be solved by a polynomial algorithm if the capacities are constant. A pseudo-polynomial algorithm is proposed for the problem with both capacitated disposal and remanufacturing. The problem with capacitated production and remanufacturing and the problem with uncapacitated production and capacitated remanufacturing are also analyzed and solved. Through numerical experiments we show that the proposed algorithms perform well when solving problems of practical sizes. From the experimental results also indicates that it is worthwhile to expand the remanufacturing capacity only when returned products exist in a relatively long planning horizon, and production capacities have little effect on the remanufacturing plan when the demand is mainly satisfied by the production.
Article Outline
1. Introduction
2. A mathematical model of capacitated dynamic lot sizing problem with production, disposal and remanufacturing
3. Several useful properties of the problem with concave cost functions
4. Several special cases of the general model
4.1. Capacitated dynamic lot sizing problem with only disposal
4.2. Capacitated dynamic lot sizing problem with only remanufacturing
4.3. Capacitated dynamic lot sizing problem with remanufacturing and disposal
4.4. Dynamic lot sizing problem with capacitated production and remanufacturing
4.5. Dynamic lot sizing problem with capacitated production and uncapacitated remanufacturing
5. Numerical experiments
6. Conclusion
Acknowledgements
References

Temporal and spatial variations of energy consumption in rural China

2009-05-10T23:50:00.003-07:00

Abstract
Presented in this paper is an overview of energy consumption in rural China in view of temporal and spatial variations. Characterized by steadily decreased proportion of biomass use and increased percentage of coal and electricity use, coal and biomass are still the major energy sources in rural areas, accounting for nearly 80% of the total rural energy consumption. Moreover, the energy consumption varies significantly across provinces both in total sum and by fuel types due to diversities of geographic features, economic development levels and local energy source availability. Three statistical groups are clustered associated with quantitative change and structural change, exhibiting evident transition from noncommercial energy pattern to commercial energy pattern. Much more work need to be done to cope with the forthcoming dramatic changes associated with booming rural economy and newly released policy from the points of both energy security and environmental pressure in China.
Article Outline
1. Introduction
2. Rural energy data
3. Overall trends of China’s rural energy consumption
3.1. General trends
3.2. Structural changes
4. Regional characteristics of China’s rural energy consumption
4.1. Quantitative differences
4.2. Structural variance
4.3. Cluster analysis
5. Conclusions
Acknowledgements
References

Homotopy analysis solution of free convection flow on a horizontal impermeable surface embedded in a saturated porous medium

2009-05-10T23:50:00.001-07:00

Abstract
In this paper, the analytic solution of the buoyancy-driven flow over a horizontal impermeable flat plate embedded in a saturated porous medium is derived using the newly developed analytic method, namely the homotopy analysis method (HAM). The HAM results show great agreement comparing with numerical results. HAM contains an auxiliary parameter that provides a simple way of controlling and adjusting the convergence region. The resultant analytic solution is valid for all acceptable values of the temperature exponent parameter λ.
Article Outline
Nomenclature
1. Introduction
2. Mathematical formulation
3. Basic idea of HAM
4. Application
5. Results
6. Conclusion
References

Modelling complex ethical decision problems with operations research

2009-05-10T23:49:00.003-07:00

Abstract
This paper discusses the practical contribution of operations research (OR) techniques to modelling decision-making problems with ethical dimensions. Such problems are frequent in the global world: they frequently appear today in sustainability issues, e.g., in conflicts in the triangle of society, economy and environment. We show that the prerequisites for ethical problem-modelling are: the definition of moral principles, the evaluation of the decision context, the participation of stakeholders, the multidisciplinary collection of data, and the understanding of systemic interconnections. Classical OR instruments, mainly used in logistics and optimisation problems, are not entirely satisfactory for coping with the new ethical dimensions of sustainability. It is recommended to use and to develop more advanced, or combined instruments from the multi-criteria/multi-stakeholder and systemic streams of OR. It is argued that an important added value of using OR techniques for modelling today ethical issues lies at least as much in the discovery of open questions as in finding closed-form solutions.
Article Outline
1. Introduction
2. Prerequisites for modelling ethical decision problems
2.1. Defining moral principles
2.2. Evaluating the decision context
2.3. Associating stakeholders
2.4. Collecting inter-disciplinary knowledge
2.5. Understanding the systemic interconnections
3. Modelling ethical problems with OR techniques
4. Conclusions
References

Why good practice of OR is not enough—Ethical challenges for the OR practitioner

2009-05-10T23:49:00.001-07:00

Abstract
This paper develops the idea that following rules of good OR practice is necessary, but not sufficient for ethical OR. Several challenges of introducing ethical aspects into OR are discussed, evidencing difficulties and ambiguities in the relationship to be established between the OR practitioner and his/her clients, decision-makers or stakeholders. It shows that neither analysis nor modelling work nor the choice of analytical tools is entirely ethically neutral; incomparability, incommensurability and incertitude must be dealt with. The purpose of this article is to detail several difficulties or dilemmas an OR practitioner may be confronted with in the course of his or her assignment. In such situations, following rules of good practice may not be sufficient to indicate how to act in a morally good way. This paper aims at stimulating reflection by structuring the debate; it may leave the reader unsettled—unsettlement being a result and even aim of many discussions in moral philosophy.
Article Outline
1. Introduction and scope
2. Good OR practice
3. Difficulties in establishing adequate real-world models
3.1. A typology of incertitude in the decision process
3.2. Narrowing boundaries in dynamic real-world modelling
4. Difficulties in establishing ethical decision-support tools
4.1. The choice of OR tools and technical parameters is not neutral
4.2. Decision criteria are frequently incommensurable
5. Difficulties in the social relationships
5.1. The existence of present or future conflicts
5.2. Change of value systems over time and cultures
5.3. The role dilemma in the relationship between OR practitioners and decision makers
5.4. The limited competence of actors
6. Conclusions
References

Does the best practice of rational-style model-based policy analysis already include ethical considerations?,

2009-05-10T22:41:00.000-07:00

Abstract
This paper deals with ethics in the context of the real-world practice of operations research (OR), once an analyst has taken on the responsibility of carrying out a rational-style model-based policy study for a client. OR models are often used by policy analysts to assist decisionmakers in choosing a good course of action based on multiple (and competing) criteria from among a variety of alternatives under uncertain conditions as part of the policy analysis process. The paper suggests that if applied operations researchers (acting as rational-style model-based policy analysts, and not as policy analysts playing a different role or as policy advocates) use the scientific method and apply the generally accepted best practices of their profession, they will be acting in an ethical manner. It, therefore, describes the steps of a typical rational-style model-based policy analysis study, and specifies the tenets of good practice in each step. It also provides a list of questions and statements that the analyst and those evaluating an analyst's work (both internally and externally) can use to help make sure that the study adheres to the tenets of good practice for rational-style model-based policy analysis and remains within ethical bounds.
Article Outline
1. Introduction
2. The context: rational-style model-based policy analysis
3. The scientific method
4. The practice of rational-style model-based policy analysis
4.1. Step 1. Formulating the problem
4.2. Step 2. Specifying objectives and deciding upon criteria
4.3. Step 3. Identifying the alternatives
4.4. Step 4. Designing scenarios to deal with uncertainty about the future
4.5. Step 5. Building the models
4.6. Step 6. Collecting the data
4.7. Step 7. Analyzing the alternatives and drawing conclusions
4.8. Step 8. Documenting the work and communicating the results
5. Internal and external evaluation
5.1. Questions related to internal processes
5.2. Questions related to interactions with the client and other stakeholders
6. Conclusions
References

How low can oil go? A lot lower, but it'll recover

2009-05-10T21:19:00.003-07:00

World oil prices could easily fall below $50 a barrel and might even slip toward $40 or perhaps $35, but they will recover and could do so fairly quickly, analysts and economists say.

Benchmark U.S. crude futures dropped to a 22-month low under $55 on Thursday as evidence mounted that the deepening recession would have a severe impact on demand, reducing the use of oil by industries and individuals alike.

Oil has now fallen more than 60 percent from July's record $147.27 a barrel and is moving close to what is widely considered to be the average operating cost, or "cash cost," for the world's oil major oil companies around $50 a barrel.

Many analysts think the market is likely to fall further, breaching the psychological $50 barrier before recovering.

"How low prices go is rather random: $50, $40, $35? It could be any of those numbers," said Kevin Norrish, analyst at Barclays Capital in London. "All we would say is that the lower it goes, the further out of equilibrium the market is headed."

The oil price collapse over the last four months has reflected several factors hitting the market at the same time.

As the gravity of the global recession has become clear, economists have recalibrated their views of oil demand.

The International Energy Agency (IEA), which advises 28 industrialized countries, on Thursday slashed its global oil demand growth forecasts.

It says demand has grown this year at the slowest rate in a generation and next year it is expected to expand by only 350,000 barrels per day (bpd).

CONSERVATIVE

World oil demand is now expected to average 86.2 million bpd in 2008, rising to just 86.5 million bpd in 2009.

Some analysts say the IEA's assumptions are too conservative and that a dramatic contraction in demand in the major developed economies will offset growth in oil demand elsewhere and produce a rare absolute fall in global demand.

Falling demand forecasts have led to widespread assumptions by oil traders that oil markets will be oversupplied.

The organization of the Petroleum Exporting Countries agreed last month to cut its oil production by 1.5 million bpd from November 1 and many analysts think it will trim its output further.

An Iranian oil official said on Thursday OPEC members would meet in Cairo on November 29 for "consultation" on the market, a move which temporarily helped push up oil prices off their lows.

Rob Laughlin, senior oil analyst at brokers MF Global, says the market could begin to turn if OPEC, responsible for pumping around 40 percent of the world's oil, trims production.

"Already some OPEC members are struggling to make money at these prices getting oil out of the ground," he said. "Look at Iran and Venezuela where the costs are relatively high. These countries are seriously feeling the pain."

Prices are already well below the average cost for the most expensive new projects -- known as the marginal cost of production -- at about $75-$80 a barrel, according to London-based analysts Bernstein Research.

David Dugdale, London-based energy analyst at MFC Global investment management, says future oil production could be curbed if oil prices fall much below $50 as many oilfields, particularly in sub-sea developments such as the North Sea, are more costly to develop.

OVER-REACTION

"If it goes to $50 or below you are going to see some supply reaction ... some cut in discretionary spending," he said.

But the impact on supply will take time to be felt: "For example, the cuts by OPEC last month could take two or three months to work into the market," he said.

In the meantime, the momentum appears to be downwards.

Driven short-term as much by sentiment in futures markets as rational calculations over fundamental costs for production, many analysts say the oil price is likely to go well beyond the level justified even by a dramatic fall in demand.

IEA chief Nobuo Tanaka said on Wednesday the price of oil was already "overshooting" to the downside: "The market is over-reacting," he told Reuters.

Analysts liken oil price moves to a weight on a piece of elastic: most of the time it swings within fairly narrow ranges, reacting to signals on supply and demand and other news but occasionally a big shock makes it swing to wild extremes.

"Just as on the upside we went too far, so on the downside, we are going too far as well," said Dugdale.

Most analysts see prices recovering fairly quickly in the next few months, according to a Reuters poll of 34 analysts last week, which produced an average forecast for WTI next year of $81.30 and almost $90 in 2010.

Barclays Capital sees the price for U.S. crude recovering to average almost $78 a barrel in the fourth quarter of this year and bouncing back to more than $105 for 2009.

"Whatever the low is, the price won't stay there for very long," Norrish said.

Study Says Violent Games Affect Boys' Heart Rates

2009-05-10T21:19:00.001-07:00

science Daily is reporting on the results of a new study on violent video games, which found that boys aged 12 to 15 experienced a greater variation in Heart Rate Variability when playing games with violent content, than they did on tamer games. The difference remained persistent during sleep, though the boys reported that they'd slept just fine.

The American Heart Association defines Heart Rate Variability (HRV) as "the oscillation in the interval between consecutive heartbeats." In layman's terms, that means a measure of minute changes in our heart rate. The researchers, who are based in Sweden, concluded that violent video games can surreptitiously affect autonomous systems within our bodies, without our ever noticing it.

While what HRV actually measures is arguably still up for debate -- some studies suggest that a suddenly lowered HRV could be linked to death in patients who've suffered a serious heart attack -- the researches hope to use their findings to study the link (should one exist) between violent video games and aggression, as well as the effects of "so-called game addiction."

I'm no scientist, but it would've been interesting to see if there were correlations between variations in a particular person's HRV and other activities that might stimulate us in the same way an action-oriented video game would -- watching sports on TV or reading a scary book, for example.

Can Good Posture Leave a Better First Impression?

2009-04-26T02:21:00.001-07:00

It takes less than six seconds to leave a first impression. It is said that we ought not judge a book by its cover, but come on, isn’t it the color, the design, the layout, and title that draws us to pick up a book we’ve never heard of before? Notice what your assumptions are about a person when you are first introduced to her or him. Spend some time people-watching and notice the assumptions you make. Is most of what you hear yourself saying negative or positive?

Something that most of us don’t take notice is how we stand or walk. The military requires soldiers to have the best postures. Why do you suppose the military trains its soldiers to march straight and tall? What possible difference can standing tall make?

Let’s say you are going for a job interview or you are networking at an event to build your business. Within seconds you have already said a lot about yourself by the way you walk. The unseen that surrounds you is the energy you are radiating which comes from your attitude and self-esteem. The seen part is your body language. How you stand and walk says volumes about you before you even say a word. The majority of us walk around everyday without paying any attention to what we are saying even though we are not uttering a word. There is a lot that can be said about body language from the clothes you wear to the gestures you make.

I took notice of this topic recently as I recalled something about changing my posture to improve my level of confidence. I was about to venture on a new project, which would take me out of my comfort zone. My gremlins were having a field day with me uttering all kinds of reasons why I couldn’t do a good job with this new opportunity. I tucked in my tummy, put my shoulders back, held my head high, and took a walk. Soon thereafter, I felt so much better. I approached the project with new zest and possibility. Wow, what a difference! Try it!

Practice standing with tummy tucked in, shoulder blades reaching to touch each other, chin up, and looking straight ahead. This exercise is quite effective regardless of body size. For those of you looking to lose weight, standing more erect gives the impression you have lost five to 15 pounds, depending on your current weight. Since pulling in my tummy and walking straighter, my friends are asking me if I lost weight. It’s so simple! It is also healthier. Walking tall may even give you the momentum to start exercising and eating more moderately if you so wish.

The ability to capture your audience when you walk into a room is sure to start you off on the right foot when going on an interview or making a presentation to prospective clients. Non-verbal signals have five times the impact of verbal signals. So you can count on losing your audience when you walk in with head down dragging your feet regardless how much you try to change it. This is a small step in making a big impression in your non-verbal communication.

Questions have the answers:

* What can be improved in the way you stand and walk?

* When you stand and walk erect what do you notice?

* When you slouch what does it feel like compared to standing erect?

* What is your assessment of someone who slouches?

* What is the posture of the leaders you admire?

* What benefits would “standing tall” have when going on an interview?

Tips:

* Here’s a Web site with great content and demonstrations on “Correct Posture”

* Correct posture can actually help you be calmer and more relaxed, which is the way you want to be on an interview or making a presentation. This can actually be put to the test. Check out the above website to see how.

* Listen to your body and feel the power as you individualize your “standing tall”

* Do you know that it is impossible to be depressed with correct posture and chin up? Try it!

* Remember to stand tall and anything is possible

Social Proof: The Worst Enemy That Lives in Your Head

2009-04-26T02:20:00.001-07:00

The concept of “social proof” (or informational social influence, if you’re a sadist for typing) tells us that, often subconsciously, individuals will look to the other people around them in ambiguous social situations to determine the appropriate way to behave. It’s a result of the subconscious mind assuming that those around us are better informed on what is acceptable and appropriate.

Unfortunately social proof became a bit of a buzzword for marketers a few years ago. Pesky buzzword or not, I think it’s a concept worth looking at from a personal development point of view. The bottom line is that the concept of social proof as described is something that is built in to the human mind and something we should be trying to build out through intellectual exercise as quickly as we can.

When your decisions are informed by the assumption that those around you are better informed than you on what the appropriate action to take is, you are destined towards several places, and none of them are good. When you make your decisions according to what other people think or do you end up quite unspectacular and rarely achieving anything of note, nor any of your dreams and goals in life.

The right attitude to assume is that you know what you want and you need to do whatever you can to get there. Obviously, acting too far outside of social norms will just have you ostracized and prevented from reaching your goals by others, so those who would argue that trying to evolve out of our in-built “social proof” mechanism causes anti-social and even criminal behavior will be pleased to know that working towards one’s goals (usually) has checks and balances like these in place. You can’t get far alone — as much as you don’t want to follow others, you do need them.

When my wife and I made the decision to move across the country to a better location, one of our considerations was the people we were living behind. Our families — our children’s grandparents, aunts and uncles — and friends live here and we felt bad about the prospect of leaving them (well, most of them!). But in the end your life is your life, and you need to take control of it and bring about the results you want to see.

That isn’t precisely social proof by the book because we weren’t taking cues from anybody but ourselves, but in the context of decision-making processes it’s the same principle at work.

If you know the results you want to create in your life and you do nothing to go about obtaining them, you are weak. There is no way of pussyfooting around that truth. To have strength of character you must always be moving towards your optimal way of life.

Maybe you’re in a situation where you can’t bring about those desired results just now, but you can at least start to plan for a time when that situation changes, or preferably, has been changed by you.

Staying because others want you to? Not going to help you achieve results. Not giving your dreams a shot because nobody else is giving theirs a shot? Definitely not going to get you anywhere. Social proof is bad. This process is probably a remnant of a time when social proof helped you decide which food was good to eat and which was poisonous; I don’t know, I’m not a scientist. All I know is that it doesn’t serve much of a purpose now. It gets in the way.

And while I know that, in a neutral state I’m as prone to it as anyone. The difference is that I do my best to catch myself and take measures — drastic if they have to be — to get out of that rut and leave the cattle behind.

To improve yourself you need to define your goals and optimal situation and work towards that regardless of whether others are doing the same. That doesn’t mean disregard and disrespect others — it means don’t make your decisions based on what others are doing, thinking, or desiring. You should still formulate decisions that mitigate the negative effects on others, and preferably have positive effects for them — but if the negative effect is an acceptable one and the rewards for your goals are worthwhile, you know what you need to do.

Five Hundred Times

2009-04-19T23:17:00.000-07:00

In the traffic court of a large mid-western city, a young lady was brought before the judge to answer a ticket given her for driving through a red light. She explained to his honor that she was a school teacher and requested an immediate disposal of her case in order that she might hasten on to her classes. A wild gleam came into the judge's eye. "You are a school teacher, eh?" said he. "Madam, I shall realize my lifelong ambition. Sit down at that table and write 'I went through a red light' five hundred times."

Stopping smoking

2009-04-13T20:31:00.000-07:00

SIR–Thank you for giving Allen Carr,the famous stop-smoking guru who founded the Easyway method,the honour of a generally excellent obituary(December 9th).

The article,however,contained a veryimportant error.You say“Since he[Allen Carr]had never submitted Easyway to independent trials orevaluation,it was impossible to tell how effective it was.”In fact Easyway has been submitted toindependent trials and evaluation and the Allen Carr organisation is currently pursuing legal action against Action on Smoking and Health(ASH)for publishing claims similar to yours.I draw your attention to two such studies conducted by eminent scientists expert in the field andpublished in peer-reviewed journals.The first is“Long-term success of short smoking-cessation seminars supported by occupational health care”by H.Moshammer and M.Neuberger,which appeared in Addictive Behaviors in 2006.The second is“Smoking cessation at the workplace:1 year success of short seminars”by H.P.Hutter et al,which was published by International Archives of Occupational Environmental Health in 2005.These wholly independent studies—the authors have never received any remuneration of any kind fromAllen Carr or his organisation—support the view that the success rate for the Allen Carr method is far superior to that of any other method,in particular to that claimed for so-called Nicotine Replacement Therapy,ie,nicotine gums,patches,etc,and to that claimed for QUIT and the National Health Service's stop-smoking clinics,which use NRT.That the government continues to ignore the Allen Carr method and pump hundreds of millions of pounds of taxpayers'money into the pockets of the pharmaceutical industry on the absurd ground that giving nicotine to nicotine addicts can help cure them of nicotine addiction is a national scandal.Allen Carr exposed this in his final work,SCANDAL,which is available as a free download from our website.

When reporting the Litvinenko affair you summed up the politics of Russia as“cynical and self-interested”and suggested that most Russians would not believe the contrasting situation that exists in Britain,where the courts and not the government decides what is law(“Murder most opaque”,December 16th).Soon after,however,you reported Tony Blair's decision to drop an investigation into bribery allegations involving BAE and Saudi officials because it would have led to ill feelings between Britain and Saudi Arabia,a key ally(“Bribe Britannia”,December 23rd).Perhaps the Russians should be forgiven their cynicism,if nothing else.

You argue that the coup in Chile led by Augusto Pinochet in 1973 was not justified because theMarxist government of Salvador Allende would“probably have imploded”(“The passing of a tyrant”,December 16th).Really?Fidel Castro's experiment hasn't imploded after 47 years.Interestingly,youropinion at the time of the coup was strikingly different.You described the chaos,the danger of civil war and how the Allende government had ridden“roughshod over congress and the courts”and youconcluded the army“had to move in the end because all constitutional means had failed to restrain agovernment that was behaving unconstitutionally”(“The end of Allende”,September 15th 1973).Ofcourse,human-rights abuses should be condemned,but wouldn't it be more honest to admit a largeproportion of the 3,000 deaths occurred inevitably during and around the coup you supported?May I add a footnote to your leader(which was a model of balanced analysis)on General Pinochet.Several obituaries(not yours)have credited him with having voluntarily relinquished power when he lost the October 1988 referendum.The truth—now well established—is that a few days before thereferendum,when it became clear he was going to lose,Pinochet tried to stage a coup to prevent it from taking place.America's State Department learnt about this,all but denounced it publicly and summoned the Chilean ambassador in Washington,DC,to express its concern.Apparently this strong intervention was instrumental in frustrating Pinochet's designs to perpetuate himself in power.Your report on Sudan mentioned that the national government“still feels no obligation to share itswealth with poorer peripheral provinces”(“Glittering towers in a war zone”,December 9th).However,the IMF has noted both that Sudan has doubled its spending on the poor recently and that the national budget has slipped into deficit because of transfers to the south and other underdeveloped regions.

Moreover,rising non-oil exports and strong private investment in agriculture and other non-oil tradable sectors contradict your observation that Sudan has the“classic symptoms of an overheating petrodollar economy”.Yes,mishaps occurred when Sudanese oilfields were developed:it is a messy,unpredictable business after all.Nevertheless,the mishaps will be rectified,and future incidents avoided,by the reinvigorated National Petroleum Commission,which places sustainable,equitable and transparent oil development at its core.Contrary to your report,experts from the Sudan People's Liberation Movement also meet the ministries of finance and energy monthly to study oil production and revenue-sharing data.Meanwhile,the World Food Programme reports that the crude mortality rate fell for the third year inDarfur during 2006,and the International Committee of the Red Cross recently stopped distributing food aid in Darfur because people are harvesting much more than previously.

These developments show the plain truth:around 70%of Darfur is secure,with bustling local markets,streets and farms and people generally getting on with their lives.We Sudanese,sadly,have grown used to prophets of doom focusing just on what divides us rather than unites us and we will continue to confound predictions of looming disaster.With regard to your leader lamenting the willingness of the British to learn Johnny Foreigner'snative tongue,perhaps you could turn your attention to persuading Britons to master their own language first(“God's worst linguists”,December 16th).I recently received a marketing leaflet advising me:“Dont wait for new year sales when there in stock now”.