Showing papers in "International Journal of Environmental Technology and Management in 2009"
TL;DR: The authors provides an analysis of the key uncertainties underlying the mathematical modelling used to construct composite indicators within the broader context of sustainability measurement, and a case study of the Environmental Sustainability Index illustrates how these uncertainties can be modelled and estimated.
Abstract: Composite indicators are very common in economic and business statistics for benchmarking the relative progress of countries in a variety of policy domains such as industrial competitiveness, sustainable development, globalisation and innovation. This article provides an analysis of the key uncertainties underlying the mathematical modelling used to construct composite indicators within the broader context of sustainability measurement. A case study of the Environmental Sustainability Index illustrates how these uncertainties can be modelled and estimated.
38 citations
TL;DR: In this paper, a questionnaire survey conducted in 11 European cities in order to explore positions and perceptions with regard to urban green space is presented, including an evaluation of the demand for urban green and its importance for economic development.
Abstract: Urban green space constitutes a crucial element of all cities. It affects the overall physical and built environment of the city, making cities attractive places not only to their own citizens, but also to external visitors and investment. In this respect, urban green space may have a role to play for economic development in terms of improving the quality of urban life, building a desirable 'city image' and advancing the position of the city in respect to its competitiveness. This article draws on a questionnaire survey conducted in 11 European cities in order to explore positions and perceptions with regard to urban green space. Emphasis is given to issues related to the economic aspects of urban green, including an evaluation of the demand for urban green and its importance for economic development. The survey explores attitudes towards alternative uses of urban green space and addresses the – critical for land use policy – issue of financing its provision, maintenance and expansion.
31 citations
TL;DR: In this paper, the suitability and effectiveness of water-hyacinth in treating domestic sewage was studied under a controlled environment of a screen-house subjected to natural conditions, and several parameters were measured and analyzed, including the Biochemical Oxygen Demand (BOD), Chemical Oxygen demand (COD), faecal coliform count, nitrate and phosphate contents, pH value, heavy metals, turbidity, odour and colour at intervals of seven days.
Abstract: Sewage management is posing serious techno-economic problems in cities, particularly in developing countries. A new technology, sewage purification by water-hyacinth (Eichhornia crassipes), is a possible solution. This paper studied the suitability and effectiveness of water-hyacinth in treating domestic sewage. A 28-day experiment was performed under a controlled environment of a screen-house subjected to natural conditions. Several parameters were measured and analysed, including the Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), faecal coliform count, nitrate and phosphate contents, pH value, heavy metals, turbidity, odour and colour at intervals of seven days. Laboratory analyses indicated that the water-hyacinth culture drastically reduced the faecal coliforms by about 80%. BOD dropped from 900 to 460 mg litre−1. COD was reduced from 1,424 to 766 mg litre−1 while the nitrogen content increased by about 77.5% and the phosphorus content rose by 63.3%. The pH value fell slightly from 8.58 to 7.81. The initial pungent odour of the raw sewage gradually disappeared during the purification period while the deep yellowish colour turned almost colourless in the final effluent sample. The sludge from the culture was rich and applicable as a bio-fertiliser. After comparison with the World Health Organisation Stream Standards, it was determined that the final effluent from water-hyacinth could be used for irrigation and fishing activities, or recycled to a flowing stream for other uses except for drinking purposes.
26 citations
TL;DR: In this article, a case study was employed to study the feasibility of using residual industrial heat for sustainable district heating system, and the results of the multi-actor analysis revealed that the municipality will have far greater success if it includes the perspectives of all the different stakeholders and encourage their participation from the early phases of project design and development.
Abstract: Addressing the climate change and energy scarcity problems are two of the most complex sustainability challenges facing not only scientists, but also policy makers. Attempts at tackling these issues should be approached from two fronts: by increasing the energy efficiency (demand side) and by promoting the usage of renewables and non-Greenhouse Gases emitting energy sources (supply side). Usually, there is an agreement among stakeholders about sustainability in general, but there is a notable disagreement about how to achieve it. Thus, this paper proposes a multi-actor modelling and analysis approach as a way forward in systematically studying the system and actors dynamics - this is necessary in order to garner cooperation that will not only get such sustainability projects started, but that will also keep them going. A case study was employed to study the feasibility of using residual industrial heat for sustainable District Heating System. The result of the multi-actor analysis reveals that the Municipality (the initiator of the project) will have far greater success if it includes the perspectives of all the different stakeholders and encourage their participation from the early phases of project design and development.
24 citations
TL;DR: In this paper, the authors introduce an approach applicable to analysing different factors influencing elements relevant in sustainable development like environmental impacts, which is built on the idea of IPAT identity and applies a chained two-factor decomposition technique for calculating numerical estimates for a larger set of contributing factors than traditionally done in applying decomposition analysis.
Abstract: This article introduces an approach applicable to analysing different factors influencing elements relevant in sustainable development like environmental impacts. The approach is built on the idea of IPAT identity and it applies a chained two-factor decomposition technique for calculating numerical estimates for a larger set of contributing factors than traditionally done in applying decomposition analysis. The empirical example identifies six different meaningful contributing factors or 'driving forces' behind change in carbon dioxide emissions from fuel combustion. The factors include changes in (1) carbon intensity of energy supply, (2) efficiency of the energy transformation system, (3) energy intensity of the national economy, (4) economic growth in terms of labour productivity, (5) share of economically active population and (6) amount of population. The empirical analysis for the years 1990-2003 is carried out for the USA, Japan, China, India, Brazil and the European Union (EU-25) as a whole and for each Member State.
22 citations
TL;DR: In this article, the authors assess how companies incorporate their environmental performance as an emerging competitive priority in manufacturing strategy, and the relationship between environmental issues and production function was analysed. But the focus was not on the environmental performance, but on the business process.
Abstract: The aim of our research was to assess how companies incorporate their environmental performance as an emerging competitive priority in manufacturing strategy. The relationship between environmental issues and production function was analysed, and reasons for considering environmental issues as a novel competitive precedence of manufacturing strategy were presented. The restrictions of this relationship were presented and courses of action for future research and managerial practices were suggested.
21 citations
TL;DR: In this article, the textural, chemical, physical and adsorptive properties of ACs prepared from each source are assessed, and the results show that ACs obtained from agricultural wastes have better adsorption properties than those obtained from commercially available ACs.
Abstract: Activated Carbon (AC) adsorbents are commonly used to remove pollutants from water because of their excellent sorption ability. However, commercially available ACs are expensive. In developing countries where economy plays a very big role, it is better to find low-cost locally available precursors, which are renewable resources for the preparation of ACs. This review focuses on ACs prepared from agricultural wastes. The textural, chemical, physical and adsorptive properties of ACs prepared from each source are assessed.
19 citations
TL;DR: In this paper, a new technique "Phytocapping" is being trialled at Rockhampton's Lakes Creek Landfill and results from this study show that Phytocaps can reduce surface methane emission 4 to 5 times more than the adjacent un-vegetated site and the thick cap (1400 mm) reduces surface methane emissions 45% more than thin cap (700 mm) while the root zone effects of 19 tree species on methane emission are also examined.
Abstract: Landfill gases, predominantly methane and carbon dioxide, are produced by the biodegradation of organic wastes. Biodegradation occur, if the water comes in contact with the buried waste. Techniques such as clay capping are used to minimise percolation of water into the landfill, or gas collection system installed to reduce methane emission into the atmosphere. The use of clay cap has proven not effective in avoiding percolation of water and the gas extraction technique is found expensive for many landfills in Australia. Thus a new technique 'Phytocapping' is being trialled at Rockhampton's Lakes Creek Landfill. Results from this study show that Phytocaps can reduce surface methane emission 4 to 5 times more than the adjacent un-vegetated site and the thick cap (1400 mm) reduces surface methane emission 45% more than the thin cap (700 mm). The root zone effects of 19 tree species on methane emission are also examined.
17 citations
TL;DR: In this paper, the authors investigate the regional impacts of demographic change on the German grid-bound infrastructure and demonstrate these effects for three scenarios in their wastewater infrastructure model for the next few decades.
Abstract: The coincidence and dynamics of population decline and aging and a new regional distribution of the population pose a new challenge for a sustainable development for which there is no historical precedent. The regional distribution of population reduction will vary considerably. Shaping the future politically means facing up to the challenges of the demographic change and thus trying to answer the question: what consequences will this change have for the infrastructure of Germany and, in particular, the grid-bound infrastructure? This question is important, since infrastructure is crucial for generating economic growth and increasing the international competitiveness of any nation. Those with political responsibility have to deal with these issues, because the way they are handled will decide on the ability of society to meet the needs of its current and future citizens in a constantly changing environment. To investigate the regional impacts of demographic change on the German grid-bound infrastructure, we selected the wastewater infrastructure for our analysis. This infrastructure is very suitable for illustrating the challenge for the water industry over the next few decades. We will demonstrate these effects for three scenarios in our wastewater infrastructure model.
17 citations
TL;DR: In this article, the surface chemistry of P1300, Picazine HP and Hydrodarco C was modified via reduction, oxidation and nitridation to improve and better understand the triclosan adsorption process.
Abstract: We report adsorption of triclosan by using activated carbons as a potential method to improve the discharge water purification process. Commercially available activated carbons, P1300, Picazine HP and Hydrodarco C, display different levels of affinity for triclosan from aqueous solution. Surface chemistry of these adsorbents were modified via reduction, oxidation and nitridation, to improve and better understand the adsorption process. The adsorption capacity was greatly influenced by surface group changes, with a decrease in relative affinity on oxidation. Nitridation enhanced the amounts adsorbed over the thermally reduced samples. Surface analysis via X-ray Photoelectron Spectroscopy (XPS) helped us identify the introduced surface functional group changes. Overall, nitridation resulted in an increased basic character of the surface exploiting the Lewis acidic nature of triclosan when it is dissolved in solution. The surface chemistry modified adsorbents suggest that adsorption from solution is a viable methodology for triclosan control during wastewater treatment.
16 citations
TL;DR: In this paper, a non-traditional approach for improving both sub-national environmental analysis capacity and engaging in low-technology and low-cost mitigation of vulnerability to waterborne disease at the village-scale is proposed.
Abstract: Western Pacific small island rural communities suffer from waterborne diseases and are among the least wealthy, most remote and resource-poor across the globe. Small landmasses, geologic composition, geographic isolation, a colonial history, and weak educational, technological and financial resources constitute significant barriers to strengthening capacity to access safe drinking water. High-technology, high-cost and complex Northern (Western) models for mitigating water access problems often prove inappropriate and unsustainable. The aim of this paper is to offer a non-traditional approach for improving both sub-national environmental analysis capacity and engaging in low-technology and low-cost mitigation of vulnerability to waterborne disease at the village-scale. The approach involves a combination of techniques, including Geographic Information Systems (GIS) training, basin management, environmental health education at the grassroots scale and working with civil society to support appropriate technologies. The findings improve understanding of remote, rural and least-wealthy small island conditions, offer guidance regarding environmental management in the Western Pacific, and provide insight for developing outreach programmes with the aim of improving conditions on similar islands globally.
TL;DR: In this article, the authors identify and reduce/eliminate the processes and activities which cause the inefficient use of resources in manufacturing processes and provide suggestions for improvements to improve the manufacturing procedures.
Abstract: Manufacturing Lead-Time (MLT) is the total time required to process a given product through a plant. Long MLT is the major cause of inefficient manufacturing, since it generates large amount of wastes and creates considerable environmental burden. In the past, a large amount of environmental pollution has been generated by manufacturing industries, most of which come from inefficient practices trough generating various types of wastes. The easiest and probably the least expensive way to cut manufacturing wastes and minimise their consequent environmental impacts is to improve the manufacturing procedures of the companies. A novel approach to do this is to identify and reduce/eliminate the processes and activities which cause the inefficient use of resources. This paper presents the MLT reduction process via identifying the value-adding and non-value adding activities. It also analyses four crucial sources of wastes which generate the greatest environmental pollution and suggestions for improvements are provided.
TL;DR: In this paper, the authors compared EIA practices and effectiveness in the Portuguese islands of the Azores and Madeira and found that most EIA project practitioners and consultants in the islands are associated with the regional government agencies.
Abstract: This paper compares Environmental Impact Assessment (EIA) practices and effectiveness in the Portuguese islands of the Azores and Madeira. This was accomplished by qualitative appraisal and evaluation of the contents of EIA statements and the characterisation of the EIA practices. Data was collected from the islands' regional environmental agencies and from the Environmental Portuguese Agency internet database. The findings reveal that most EIA project practitioners and consultants in the islands are associated with the regional government agencies. Proposals were generally approved with 'conditions' and the diversity of project types were lower in the islands than in the mainland. There was limited follow-up on the EIA process so that evaluation of conditions compliance was scanty. Key areas identified for consideration in the development of good impact assessment practice in the islands included, the Islands' unique geographical and ecological characteristics, scale effects, intra-insular regional dimension, impact significance evaluation approaches, and training, education and development skills in EIA processes.
TL;DR: In this article, the authors address the evolution of environmental policies in Japan and China and propose viable measures towards a sustainable Asia and take into account the experience of Japan in addressing its environmental issues and is based on the reduce, reuse, recycle (3R) initiative.
Abstract: One of the biggest challenges Asian nations face is how to increase their economic growth while minimising the impact on the environment and reducing their dependence on imported resources. Japan paid great attention to its condition as a resource-dependent country after the oil crisis in the mid 1970's and now has one of the most eco-efficient economies in the world. The rapid economic growth of China in the last two decades has also pushed the government to focus on improving efficiency as it is shown in its 11th five year plan. This article addresses the evolution of environmental policies in Japan and China and proposes viable measures towards a sustainable Asia. These measures take into account the experience of Japan in addressing its environmental issues and is based on the reduce, reuse, recycle (3R) initiative.
TL;DR: A social survey carried out for more than 300 farmers in the Gaza Strip showed that the scarcity of organic fertilisers and their high prices could encourage farmers to use treated sludge instead of importing organic fertilizers as mentioned in this paper.
Abstract: The local production of organic fertiliser in the Gaza Strip is 66,800 m 3 /year, which represents only 8.5% of the required quantities. This means that farmers have to import 728,000 m 3 of organic fertiliser per year, which costs around 10.2 Mio US$. The social survey carried out for more than 300 farmers in the Gaza Strip shows that the scarcity of organic fertilisers and their high prices could encourage farmers to use treated sludge instead of importing organic fertilisers. The farmers who have not used sludge before are willing to use it if it is well treated and shows good results after application. Also sludge can be used as soil conditioner if it is composted as imported compost materials used in the Gaza Strip.
TL;DR: In this article, the authors provide a very clear analysis and quantification of all the parameters of the process that make a major contribution to environmental impact, including raw material acquisition, industrial production, packaging and transportation.
Abstract: The basic targets of the modern cement and concrete production industry are the reduction of energy costs and minimisation of environmental effects. Life Cycle Assessment (LCA) is a useful tool for the evaluation of the environmental performance of a production system. The objective of this work is to provide a very clear analysis and quantification of all the parameters of the process that make a major contribution to environmental impact. The system investigated includes raw material acquisition, industrial production, packaging and transportation, use of the product, demolition and its final disposal. The cement production stage contributes the most to the environmental pollution.
TL;DR: In this article, a case study of the Dutch residential building industry is used to evaluate the performance of a national system of sustainable innovation using case studies of Dutch residential buildings over a 16-year period.
Abstract: This paper provides an assessment of the performance of a national system of sustainable innovation using a case study of the Dutch residential building industry. This project covered a 16-year period. Normally, a nation's population of commercial firms and research institutions should have the lead in the development of a sustainable innovation organisation, with the government in a supporting role. However, our study showed that the government took a central role with just a few specialised firms in a supporting role, and with a majority of the firms in industry acting passively. Despite this contradiction, the innovation system functioned very well, and showed significant results.
TL;DR: In this paper, a simulation/evaluation model that reflects material balance and evaluates the regional environmental policies with utilising biomass resources was proposed to evaluate the regional water pollution and global warming.
Abstract: Due to the principles of mass balance, there is a trade-off between regional water pollution and global warming. However, local governments in charge of water pollution control usually try to reduce water pollution loads without thinking of the influences on global warming. This study aims to formulate a simulation/evaluation model that reflects material balance and evaluates the regional environmental policies with utilising biomass resources. In the simulation, introduction of biomass utilisation plants was chosen as an effective tool to reduce environmental pollutants and substitution occurs between nitrogen monoxide and Total Nitrogen during the emission of nitrogen into the environment. These results implies that promotion of biomass resource utilisation can improve both the environment and economy and policy making for water quality improvement should also take into account the effects on global warming of policy measures. Eliminating vertically divided administrative functions becomes essential for resolution of global environmental problems.
TL;DR: In this article, the authors analyse the intensity of the adoption of Information and Communication Technologies (ICTs) in Small and Medium-SMEs in Mauritius and Jamaica and identify enabling factors and impediments that are specific to small islands in the diffusion of ICTs.
Abstract: The aim of this study was to analyse the intensity of the adoption of Information and Communication Technologies (ICTs) in Small- and Medium-sized Enterprises (SMEs) in Mauritius and Jamaica. It particularly focused on the identification of enabling factors and impediments that are specific to small islands in the diffusion of ICTs. Discriminant analysis was used to analyse the data collected from small firms in both islands. The results show that, despite the liberalisation and privatisation of the communication sectors in these island economies, cost of communication remained one of the major impediments to the adoption of e-business technologies. This could be attributed to the lack of minimum economies of scale in communication sectors. Enterprise-specific factors such as education and knowledge base of owners and firm size emerged as significant discriminants for advanced users of ICTs. Country-specific factors such as openness of economy and human resource development infrastructure emerged as important factors in discriminating varying levels of ICT-using firms.
TL;DR: In this paper, a linearised Langmuir isotherm was used to represent the equilibrium uptake for the range of operating conditions studied for batch equilibrium experiments for the sorption of Bismarck brown onto rubber wood saw dust particles.
Abstract: Batch equilibrium experiments were carried out for the sorption of Bismarck brown onto rubber wood saw dust particles. The operating variables studied were the initial dye concentration, particle diameter and solution temperature. A linearised Langmuir isotherm was found to well represent the equilibrium uptake for the range of operating conditions studied. The monolayer sorption capacity of rubber wood saw dust for the sorption of Bismarck brown was estimated to be 35 mg g−1. The sorption capacity was found to increase with decreasing particle size. The negative value of ΔG and ΔH suggests the spontaneity and exothermic nature of the process.
TL;DR: Wang et al. as discussed by the authors proposed that circular economy development in China should be based on new mechanism of five cardinal points, namely "enterprise actors, industry-level self-regulation, public participation, policy underpinnings and technical underbinnings", and that recycling system for recycling resources should include individual (and/or company) and demonstration recycling zone.
Abstract: According to data on recycling waste in the Zhejiang province, P. R. China, rapid and active growth of regional featuring economy in the Zhejiang province that is lack of resource is due to four new cardinal points, namely recycling waste, industrial agglomeration, central wholesale market and privatising system. Especially, that Zhejiang leads in regional featuring economy in China is mainly based on circular economy (CE). Through field studies on regional development in the Zhejiang province, circular economy in the Zhejiang province experienced two development stages, named 'resources utilised briefly' and 'resources utilised high-efficiently' that solved two issues of resource and environment effectively. Further, circular economy development in China should be based on new mechanism of five cardinal points, namely 'enterprise actors, industry-level self-regulation, public participation, policy underpinnings and technical underpinnings'. In addition, that recycling system for recycling resources should include individual (and/or company) and demonstration recycling zone was discussed.
TL;DR: In this paper, an air quality modelling assessment of trans-boundary air pollutants from the Asian continent by applying an advanced modelling system (CMAQ) developed by the US Environmental Protection Agency (USEPA) is conducted.
Abstract: The purpose of this study is to conduct an air quality modelling assessment of trans-boundary air pollutants from the Asian continent by applying an advanced modelling system – the Community Multi-scale Air Quality (CMAQ) – developed by the US Environmental Protection Agency (USEPA). The focus of the study is trans-boundary ozone, Particulate Matter (PM), and acid deposition, using selected episodes of both non-trans-boundary and trans-boundary scenarios in order to provide an understanding of the characteristics of air pollutants for decision- and policy-makers in Taiwan and its islands. The study demonstrates that the Models-3/CMAQ system is capable of simulating key criteria pollutants reasonably well during a typical day, and within an acceptable run time. The CMAQ system has been designed to simulate air quality, as a whole, by including state-of-the-science capabilities for tropospheric ozone, fine particles, toxics, acid deposition and visibility degradation. It provides additional profiles for decision- and policy-makers, and assists the Taiwan Environmental Protection Administration (TEPA) in developing control strategies to improve air quality in the Taiwan Islands. We conclude that the methods used in this paper are readily transferable to most air quality data sets, and that the CMAQ system can be applied to other small islands around the world.
TL;DR: In this article, the interrelationships of sustainability, growth and the improvement in quality of life are discussed through a stakeholder approach where 'green' yardsticks are explored and related to productivity.
Abstract: Every organisation must ensure that its responsibilities are encompassed within its legal, social and economic domains. Environmental and productivity issues thus need to be entwined to form the foundation of such an effective corporate strategy. The inter-relationships of sustainability, growth and the improvement in quality of life are discussed through a stakeholder approach where 'green' yardsticks are explored and related to productivity. A framework for analysis is constructed, illustrating the flow from inputs, through processes, to outputs and, ultimately, to outcomes, highlighting impacts on society. Such a perspective can be perceived as the contemporary sustainability vision through sensible resource utilisation.
TL;DR: In this paper, the authors investigate the level of social consensus on and support of the development of an energy plant based on the use of vegetal biomass in Central Sardinia, Italy.
Abstract: Warming-up of the planet and scarcity of conventional energy resources has led to aim of reducing the consumption of fossil fuels and the development of innovative renewable technologies for energy production. However, innovations and investments in renewable energy can encounter resistance of local communities. This makes planning for the development of Renewable Energy Source-based power plants often very difficult. Against this background, we investigate the level of social consensus on and support of the development of an energy plant based on the use of vegetal biomass in Central Sardinia, Italy. The method adopted is Contingent Valuation. Estimates of ex-ante household Willingness To Pay are implemented, as they are important indicators of the social endorsement for the project development. Implications concerning consensus/disagreement on innovative technologies for sustainable energy production are discussed as perspectives of future research.
TL;DR: In this paper, the authors analyse technical performance under different environmental regimes in a sample of small and medium sized enterprises in Dutch horticulture and find that new, environmentally friendly technology improves technical efficiency.
Abstract: An important strategy for a firm to improve its environmental performance is adoption of environmentally friendly technology. However, technology switching is often hampered by high investments costs. If the environmental friendly technology would also lead to an increase in technical efficiency firms might more easily decide to switch technology. However, the empirical evidence for improved technical efficiency is still very scarce. In this article, we analyse technical performance under different environmental regimes in a sample of small and medium sized enterprises in Dutch horticulture. Some firms use traditional technology while others use modern technology. The latter is more environmentally friendly than the former in terms of use of energy and water. We apply a stochastic production frontier framework to analyse the impacts of environmental technologies on technical efficiency. The data is obtained from a stratified sample of Dutch greenhouse firms included in the so-called Farm Accountancy Data Network and the LEI Innovation monitor. The main result is that new, environmentally friendly technology improves technical efficiency.
TL;DR: In this paper, the authors assess the effects of environmental factors and equipment configuration on the recovery of soil water using a solar collector and find that the amount of water collected depended largely upon the air temperature and soil water content.
Abstract: The aim of this paper is to assess the effects of environmental factors and equipment configuration on the recovery of soil water using a solar collector The recovery of water from soil is difficult, since the energy requirements are very high Solar energy provides a solution to this problem, especially in countries with high solar radiation In the current study, it was found that the amount of water collected depended largely upon the air temperature and soil water content In winter, 0465 L m−2 day−1 were collected compared to 1163 L m−2 day−1 in summer The initial soil water content was equally important; dry soil tended to yield less condensate than wet soil Saturated soils yielded 0814 L m−2 day−1 in winter compared to 1395 L m−2 day−1 in summer The type of soil (ie gravel, silt and loamy sand) affected the release of water from the surface, as a result of differences in soil water release characteristics The air space between the soil surface and the condensate collecting surface also had an effect on condensate collection; the larger this distance, the greater the amount of condensate that was collected The configuration of the condensate collecting surface also had an effect on the amount of condensate obtained; the shallower the slope of the surface, the greater the amount of condensate that was collected The collector was most effective in summer, on cloudless days, with wet poorly-drained silt soils
TL;DR: In this paper, a stochastic dynamic optimisation model is set up that derives the path and combination of control options that maximise the expected net present value of returns from a pasture.
Abstract: Invasive plants can cause significant problems in natural and agricultural ecosystems. It is recognised that biological agents may assist in controlling invasions, but due to stochastic effects of biological control, the biological agent may not be effective. In this article, we analyse to what extent the stochastic effects of a biological control agent affect the optimal choice of control strategies to deal with the invasion of the Californian thistle in New Zealand. A stochastic dynamic optimisation model is set up that derives the path and combination of control options that maximise the expected net present value of returns from a pasture. The analysis focuses on two situations: a deterministic case and a second case in which the effect of introducing the insect Apion onopordi to reduce thistle density is stochastic. Although one would expect that the stochastic specification would lead to different results, we show that the stochasticity of the efficacy of the insect in this specific setting does not affect the optimal control measure adopted compared to the deterministic case. It is also shown that chemicals can be replaced as a control option by more environmentally friendly control options at relatively low costs.
TL;DR: In this paper, the authors proposed a cost-profit analysis model for multilateral recycling system considering the differentials of economic factors between developed and developing countries at first, based on this model, they conducted cost profit analysis of multi-ilateral recycling of four electronic products, namely, refrigerator, television, air conditioner and personal computer.
Abstract: The objective of this study is to clarify quantitatively the driving force of multilateral recycling system in Asia, especially focusing on economic factors. To this end, we proposed a cost-profit analysis model for multilateral recycling system considering the differentials of economic factors between developed and developing countries at first. Based on this model, we conducted cost-profit analysis of multilateral recycling of four electronic products, namely, refrigerator, television, air conditioner and personal computer, to identify dominant economic drivers of multilateral recycling system in Asia. The result of analysis showed that high profitability and recycling ratio can be achieved by multilateral recycling system in spite of its extra transportation cost, mainly due to low labour cost in developing countries.
TL;DR: In this paper, the authors used Geographic Information Systems (GIS) to identify airborne fungi that can contribute to asthma incidence in the central eastern region of the island of Puerto Rico.
Abstract: Asthma is a growing worldwide chronic disease increasing in both prevalence and exacerbations throughout the late 20th century. The US. Centre for Disease Control reports showed that Puerto Rico had a higher overall prevalence of lifetime (19.6%) and current (11.6%) asthma. The central eastern region of the island has the highest prevalence in the age range of 0-17. The goal of this study was to isolate and identify airborne fungi that can contribute to asthma incidence in this part of the island. Air was sampled from 11 communities in the municipality of Caguas. A total of 514 isolates were identified to genus and spatial distribution of the identified fungi was completed using Geographic Information Systems to address potential geomorphologic and anthropogenic contributors for their presence. Four of the top six locations sampled with the highest number of colonies were classified as urban. These sites are developed areas and have moderate to high vehicular traffic. This work revealed the presence of fungal allergens that can be potential asthma triggers and establishes a rationale for future research in this area.
TL;DR: In this paper, the authors investigated how environmental information can be collected and brought back to the mainland from the Great Barrier Reef (GBR) by using the evaporation duct above the ocean surface to tunnel radio signals beyond the horizon.
Abstract: The Great Barrier Reef (GBR) is the largest natural feature on earth, stretching more than 2300 km along the northeast coast of Australia. It contains a diverse array of species and habitats that are threatened by environmental and human impacts. Monitoring environmental changes would give a better understanding of the health of this ecological system. It would also help shape decision-making to ensure this important natural asset is protected into the future. This paper investigates how environmental information can be collected and brought back to the mainland from the GBR. A novel method of using the evaporation duct above the ocean surface to tunnel radio signals beyond the horizon is proposed for the link to the mainland, and the design of a hybrid power supply is also outlined. A monitoring network for use on Davies Reef, approximately 80 km off the coast of northern Queensland, is used as a case study in this paper.