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1.
Phosphorus-containing moieties can be added to the ninth and/or tenth positions of a fatty chain of a methyl ester utilising an epoxide route. In this route, methyl oleate is epoxidised, and then ring opened using dibutyl phosphate to yield – among others – a dioxaphospholane-containing derivative of methyl octadecanoate. Progress of the reaction was determined by gas chromatography-mass spectrometry and compounds were identified by nuclear magnetic resonance spectroscopy. Addition of a titanium and zirconium oxide catalyst increased the yield of dioxaphospholane from 27%, observed without catalyst, to 37%. A similar reaction using bis-2-ethylhexyl phosphate gave 22% and 29% yield. However, an aryl phosphate, diphenyl phosphate, was not active in these reactions. The aliphatic compounds obtained are likely to be useful sulphur and metal-free extreme pressure lubricant additives which are highly compatible with vegetable oil-based lubricants.  相似文献   

2.
In the context of assessing potential risks of engineered nanoparticles (ENPs), life cycle thinking can represent a holistic view on the impacts of ENPs through the entire value chain of nano-enhanced products from production, through use, and finally to disposal. Exposure to ENPs in consumer or environmental settings may either be to the original, pristine ENPs, or more likely, to ENPs that have been incorporated into products, released, aged and transformed. Here, key product-use related aging and transformation processes affecting ENPs are reviewed. The focus is on processes resulting in ENP release and on the transformation(s) the released particles undergo in the use and disposal phases of its product life cycle for several nanomaterials (Ag, ZnO, TiO2, carbon nanotubes, CeO2, SiO2 etc.). These include photochemical transformations, oxidation and reduction, dissolution, precipitation, adsorption and desorption, combustion, abrasion and biotransformation, among other biogeochemical processes. To date, few studies have tried to establish what changes the ENPs undergo when they are incorporated into, and released from, products. As a result there is major uncertainty as to the state of many ENPs following their release because much of current testing on pristine ENPs may not be fully relevant for risk assessment purposes. The goal of this present review is therefore to use knowledge on the life cycle of nano-products to derive possible transformations common ENPs in nano-products may undergo based on how these products will be used by the consumer and eventually discarded. By determining specific gaps in knowledge of the ENP transformation process, this approach should prove useful in narrowing the number of physical experiments that need to be conducted and illuminate where more focused effort can be placed.  相似文献   

3.
In recent years there has been an increasing awareness of the radiological impact of non-nuclear industries that extract and/or process ores and minerals containing naturally occurring radioactive material (NORM). These industrial activities may result in significant radioactive contamination of (by-) products, wastes and plant installations. In this study, scale samples were collected from a decommissioned phosphoric acid processing plant. To determine the nature and concentration of NORM retained in pipe-work and associated process plant, four main areas of the site were investigated: (1) the 'Green Acid Plant', where crude acid was concentrated; (2) the green acid storage tanks; (3) the Purified White Acid (PWA) plant, where inorganic impurities were removed; and (4) the solid waste, disposed of on-site as landfill. The scale samples predominantly comprise the following: fluorides (e.g. ralstonite); calcium sulphate (e.g. gypsum); and an assemblage of mixed fluorides and phosphates (e.g. iron fluoride hydrate, calcium phosphate), respectively. The radioactive inventory is dominated by 238U and its decay chain products, and significant fractionation along the series occurs. Compared to the feedstock ore, elevated concentrations (< or =8.8 Bq/g) of 238U were found to be retained in installations where the process stream was rich in fluorides and phosphates. In addition, enriched levels (< or =11 Bq/g) of 226Ra were found in association with precipitates of calcium sulphate. Water extraction tests indicate that many of the scales and waste contain significantly soluble materials and readily release radioactivity into solution.  相似文献   

4.
The expected widespread use of carbon nanotube (CNT)-composites in consumer products calls for an assessment of the possible release and exposure to workers, consumers and the environment. Release of CNTs may occur at all steps in the life cycle of products, but to date only limited information is available about release of CNTs from actual products and articles. As a starting point for exposure assessment, exploring sources and pathways of release helps to identify relevant applications and situations where the environment and especially humans may encounter releases of CNTs. It is the aim of this review to identify various potential release scenarios for CNTs used in polymers and identify the greatest likelihood of release at the various stages throughout the life-cycle of the product. The available information on release of CNTs from products and articles is reviewed in a first part. In a second part nine relevant release scenarios are described in detail: injection molding, manufacturing, sports equipment, electronics, windmill blades, fuel system components, tires, textiles, incineration, and landfills. Release from products can potentially occur by two pathways; (a) where free CNTs are released directly, or more frequently (b) where the initial release is a particle with CNTs embedded in the matrix, potentially followed by the subsequent release of CNTs from the matrix.The potential for release during manufacturing exists for all scenarios, however, this is also the situation when exposure can be best controlled. For most of the other life cycle stages and their corresponding release scenarios, potential release of CNTs can be considered to be low, but it cannot be excluded totally. Direct release to the environment is also considered to be very low for most scenarios except for the use of CNTs in tires where significant abrasion during use and release into the environment would occur. Also the possible future use of CNTs in textiles could result in consumer exposure. A possibility for significant release also exists during recycling operations when the polymers containing CNTs are handled together with other polymers and mainly occupational users would be exposed.It can be concluded that in general, significant release of CNTs from products and articles is unlikely except in manufacturing and subsequent processing, tires, recycling, and potentially in textiles. However except for high energy machining processes, most likely the resulting exposure for these scenarios will be low and to a non-pristine form of CNTs. Actual exposure studies, which quantify the amount of material released should be conducted to provide further evidence for this conclusion.  相似文献   

5.
A major diesel emissions research program has been initiated by the U.S. Environmental Protection Agency to assess the human health risk associated with increased use of diesel automobiles. This program is intended to establish the mutagenic and carcinogenic potency of complex organics associated with diesel particles as well as comparative particle-bound organics from other environmental emissions for which human epidemiological data are available. The mobile source samples selected for this study were collected from a heavy-duty diesel engine, a series of light-duty diesel passenger cars, and a gasoline catalyst automobile. The comparative source samples incorporated into the study were cigarette smoke condensate, coke oven emissions, roofing tar emissions, and benzo(a)pyrene. The samples were tested using three mutagenic assays and four carcinogenic assays as prescribed by a test matrix. This report describes the study design, particle generation, and sample collection and preparation. A brief summary of the bioassays is also included.  相似文献   

6.
A Framework for Assessing Carbon Flow in Indian Wood Products   总被引:4,自引:0,他引:4  
This paper uses a lifecycle analysis to trace the fate of carbon bound in wood products until most of the carbon is released back into the atmosphere. A sensitivity analysis has been carried out to find the effect of change in terminal use (recycling, land filling and burning of discarded products), half-life of wood products and decay rate of carbon in landfills. Of the total carbon harvested from forests in India, about 90% is released into the atmosphere in the first year, due to burning of fuelwood; at the end of 100 years, about 0.8% still remains in the wood products. The sensitivity analysis shows that the length of the lifespan of wood products has only a marginal effect on the amount of carbon sequestered but has significant effect on the amount of carbon in products in use. Thus an important conclusion from this scenario is that by increasing the durability of the wood products, carbon can be locked over a period equal to the time needed to grow the timber for these products. Further, the carbon storage is affected more significantly by the decay rate of carbon in landfills than the proportion of products recycled. The study also shows that wood products can be important stores of carbon, but only if they can substitute for a unit of carbon emitted by burning fossil fuels. Such a lifecycle analysis has the potential to account completely for carbon stock changes in the wood products, where and when they are occurring, and explain how they are occurring.  相似文献   

7.
Nanotechnology-infused products have begun to enter the market in spite of the fact that many sectors of society are still debating whether or not exposure to such products will result in detrimental side effects. Due to a lack of regulation of nanoproducts, it is difficult to track these products to assess how they interact with humans and the environment. Acknowledging this limitation, several studies are starting to investigate situations where individuals are exposed to nanoparticles in the workplace; it is to be noted that manufacturing of materials is the first stage in the product life cycle where exposure may occur. This paper reviews and discusses the potential societal implications associated with the manufacturing of nanoparticles: health concerns, workers’ perceptions, rights, ethics, and the role of policy and regulation. Scenarios are presented, possible implications are discussed, and recommendations are given for appropriate action. Finding the right solution to the identified implications represents a critical challenge. In summary, it is imperative that all stakeholders including industry, academia, government entities, and the public adopt a proactive attitude to ensure that nanotechnology matures in a sustainable manner.  相似文献   

8.
Abstract

The increasing awareness of climate change has led organizations to demand a standard procedure to measure and communicate greenhouse gas (GHG) emissions linked to their products or services. The publicly available specification PAS 2050 has been developed in response to broad community and industry desire for a consistent method-carbon footprint for assessing the life cycle GHG emissions of goods and services. Specifically, this paper illustrates the implementation of carbon footprint for a baby stroller in accordance with PAS 2050. A fial value of 321 kg per one stroller including package was calculated. Moreover, the study led to identify raw materials production of the stroller as the main source of GHS emissions where efforts need to focus for emission reduction opportunities. This case study is hoped to be a starting point for organizations to benefit from the increasing application of carbon footprint assessment.  相似文献   

9.
The demand for petroleum products in India has been increasing at a rate higher than the increase of domestic availability. At the same time, there is continuous pressure on emission control through periodically tightened regulations particularly in metropolitan cities. In the wake of this situation, there is an urgent need to promote the use of alternative fuels as substitutes for high-speed diesel. Dual-fuel mode of operation employing compressed natural gas (CNG) and plant oils such as Honge and Jatropha oils and their esters is an attractive option as our country has a large agriculture base that can be a feedstock to this fuel technology which can ease the burden on the economy by curtailing fuel imports. This paper presents the results of investigations carried out in studying the behaviour of Honge and Jatropha oil methyl esters and their blends with 15% ethanol and subsequent testing of these oils in a four-stroke, single-cylinder, water-cooled, direct-injection compression ignition engine in dual-fuel mode with CNG induction.  相似文献   

10.
Our previous paper entitled "Paradoxical ozone associations could be due to methyl nitrite from combustion of methyl ethers or esters in engine fuels" (Env. Int.. 2007;33;1090) reviewed 11 studies of the impact of ozone on human health that, paradoxically, found a negative coefficient for ozone-morbidity associations. We argued that the most likely explanation for this effect would be methyl nitrite (MN) as an unsuspected exhaust component of engines with methyl ether in the fuel. The basis of the argument was the fact that MN is rapidly destroyed by sunlight, so that MN would be negatively correlated with ozone. All (but one) of the reviewed studies concluded that criterion pollutants could not explain the negative slope. The argument was strengthened by the observation that such paradoxical ozone associations have not been found in regions without significant methyl ether in gasoline. Left unaddressed in the previous paper was the possibility that fine particulate matter (FPM) might explain the POA. If this were true, then it would be necessary that the FPM be negatively correlated with ozone in those regions that found a POA. The current paper reviews data on FPM-ozone correlations in those regions where a POA was identified. The results show that FPM was, in most cases, positively correlated with ozone and so could not explain the POA.  相似文献   

11.
Skin tumors can be induced by the sequential application of a subthreshold dose of a carcinogen (initiation phase), followed by repetitive treatment with a noncarcinogenic tumor promoter. There is a very good dose-response relationship between the induction of the number of papillomas per mouse at early times (10 to 20 weeks) by either tumor initiators and promoters and the final carcinoma incidence after a longer latency (20 to 50 weeks) in SENCAR mice. This system not only can be used to determine the tumor initiating and promoting activities of a compound but if the agent is given repeatedly by itself one can also determine if it is a complete carcinogen, i.e., if it has both tumor initiating and promoting activity. In addition, if the agent is given concurrently with a known complete carcinogen or a tumor initiator one can also determine if the agent has cocarcinogenic or cotumor initiating activity or even possibly anticarcinogenic activity. Likewise, if the agent is given concurrently with a known tumor promoter one can determine if the agent has copromoting or antipromoting activity. Using the SENCAR skin carcinogenesis system we have undertaken the determination of the skin carcinogenic, cocarcinogenic, tumor initiating and promoting activities of various diesel emission particle extracts as well as for comparative purposes, standards such as benzo(a)pyrene and 12-0-tetradecanoylphorbol-13-acetate and extracts of emissions from a gasoline engine, roofing tar, coke oven and cigarette smoke condensate. Most of the studies are still in progress but some preliminary data is available on the comparative tumor initiating activities of the various samples at 14 weeks. Caterpillar diesel and cigarette smoke condensate were essentially without activity, whereas the Mustang gasoline catalyst and Olds diesel gave extremely low values although they were slightly above background. Roofing tar, coke oven and Nissan Diesel all gave moderate activity at high doses (1 to 10 mg) but when compared to benzo(a)pyrene were relatively low values.  相似文献   

12.
Most retail and on-line outlets allow customers to easily return defective or even non-defective products. Due to increasing environmental and sustainable concerns, disposal of returned products is often costly and undesirable. Furthermore, these products contain parts and materials of value that can contribute to the companies' profit. One way to take advantage of these returns is by utilising good returned parts in production of after-market products. Recycling of parts from products at the end of their useful lives has been studied for a long time. Many of these studies, however, are focused on repairs and refurbishing of such products for reuse.

This paper addresses recycling of rather new parts recovered from returned products. In this process parts are assembled with other parts recovered from other products to make a complete unit. The main objective of this study is to provide quantitative decision rules for justification of recycling of returned parts. The proposed method consists of a computer-based simulation decision model that, given a set of production system parameters, determines the breakeven point for the primary production rate at which recycling is justified. The application of the system to several scenarios is demonstrated through a numerical example.  相似文献   

13.
Non-invasive matrices in human biomonitoring: a review   总被引:1,自引:0,他引:1  
Humans and other living organisms are exposed to a variety of chemical pollutants that are released into the environment as a consequence of anthropogenic activities. Environmental pollutants are incorporated into the organism by different routes and can then be stored and distributed in different tissues, which leads to an internal concentration that can induce different alterations, adverse effects and/or diseases. Control measures should be taken to avoid these effects and human biomonitoring is a very useful tool that can contribute to this aim. Human biomonitoring uses different matrices to measure the target chemicals depending on the chemical, the amount of matrix necessary for the analysis and the detection limit (LOD) of the analytical technique. Blood is the ideal matrix for most chemicals due to its contact with the whole organism and its equilibrium with organs and tissues where chemicals are stored. However, it has an important disadvantage of being an invasive matrix. The development of new methodology and modern analytical techniques has allowed the use of other matrices that are less or non-invasive, such as saliva, urine, meconium, nails, hair, and semen or breast milk. The presence of a chemical in these matrices reflects an exposure, but correlations between levels in non-invasive matrices and blood must be established to ensure that these levels are related to the total body burden. The development of new biomarkers that are measurable in these matrices will improve non-invasive biomonitoring. This paper reviews studies that measure Cd, Pb, Hg, polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), polycyclic aromatic hydrocarbons (PAHs), polybrominated diphenyl ethers (PBDEs), organochlorine pesticides and phthalates in non-invasive matrices, the most used techniques for measurements and what alternative techniques are available.  相似文献   

14.
The concept of participation in rural development has been evolutionary for the past two decades with those involved, such as development agencies and governments, particularly in rural water supply, re-evaluating their active role. The move towards effective community participation has encouraged a shift from the traditional top-down to a bottom-up approach whereby there is a decentralisation of unevenly distributed resources and power to empower a community and allow mobility of ‘people participation’. The Molinos water project is the first large-scale development project of its kind introduced into the village of Molinos in an under-developed area of Chile, where there has been no tradition of people participation. The project objective was to implement a low technology, low budget water treatment plant to the village of Molinos. Various aspects have hindered the continued development of the project including both technical and financial. In terms of people participation, the initial approach used was the top-down approach. There was a failure to fully integrate the community or inform the community in a formal manner about the project and consult them regarding key project issues. This case study illustrates that the lack of comprehensive consultation and the low level of participation of the community on the participatory scale does not achieve much in terms of people-centred benefits. For governance at the local level to be effective, participation should be inclusive and communicative so as to enhance transparency throughout the project lifetime. Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue.  相似文献   

15.
The World Summit on Sustainable Development (WSSD), held in Johannesburg during 26 August and 4 September 2002, was a truly remarkable event, not least because it identified and committed the world community to what has to be done to realise Agenda 21 objectives. Discussion begins with the "means of implementation" of the Johannesburg Plan of Implementation (JPI). Education for, and raising awareness of, sustainable development are the key commitments in the "means of implementation". The issues central to these commitments are discussed. The crucial role of moral philosophy in education for sustainable development is then discussed. Defining the "problem" as lack of progress (in fact negative progress between Rio and Johannesburg) towards global sustainable development, a cause–effect relationship of the "problem" is developed based on a systematic and logical analysis. It shows that the "cause" is West's profoundly materialistic, environment-degrading and exploitative attitude and activities to satisfy grossly unsustainable, hedonistic and insatiably avaricious Western life-styles – life-styles that are held up by the West as "ideal" fruits of economic "development" to be aspired by all. The "effects" are pollution of air, water and soil; mounting loss of biodiversity, ecosystems and species; relentlessly widening north–south divide, etc. It is argued that while science and technology can address some of the "effects", they cannot address the "cause". Only moral philosophy can by fundamentally re-orienting moral values genuinely to respect nature and the environment. Based on sound and tested principles of Educational Psychology, a proposal is then made for including moral philosophy in the formal curricula (content and pedagogy) of primary, secondary and higher education for instilling in children and young people genuinely environment-respecting moral values. To this end a generic syllabus for the secondary level is proposed. Finally, it is argued that if the scientific community really believes that science or technology alone can radically change the pervasive environment-degrading moral values to those that genuinely respect the environment, thus paving the way to real global sustainability, then it must demonstrate how this could be done and explain why, despite their abundant science and technology, the developed nations are the biggest polluters and consumers with grossly unsustainable life-styles. Certainly, examples would be much more convincing than rhetoric or tired old clichés about how science and technology alone could deliver global sustainable development.  相似文献   

16.
This paper presents a feasibility study of Marotti oil biodiesel as an alternative to diesel fuel for a compression ignition engine. Marotti oil is inedible and available mainly in the state of Kerala. The oil is extracted from Marotti seeds. However, the high viscosity, poor volatility and cold flow characteristics of many vegetable oils in general, and Marotti oil in particular, can cause problems such as injector coking, severe engine deposits, filter gumming, piston ring sticking and thickening of lubrication from long-term use in diesel engines. These problems can be eliminated or minimised by transesterification of the vegetable oils to form monoesters. Although transesterification improves the fuel properties of vegetable oil, the viscosity and volatility of biodiesel are still worse than for petroleum diesel fuel. Subsequently, Marotti oil was converted into its methyl ester by the process of transesterification. The methyl ester was blended with diesel in various proportions to obtain different blends of Marotti oil with diesel. The performance, emission and combustion characteristics of Marotti methyl ester and its blends with diesel were studied and the results were compared with the base line data generated for diesel operation. Experiments were conducted using an injection timing of 23° before top dead centre (BTDC) and an injection pressure of 205 bar at various power outputs and at a constant rated speed of 1500 rpm. The engine manufacturer specifies an injection timing of 23° BTDC and injection pressure of 205 bar for the standard diesel fuel operation. The heat release rates, maximum rate of pressure rise, ignition delay and combustion duration for these fuel combinations were obtained.

From the results obtained, it was observed that the biodiesel produced from Marotti oil and its blends with diesel have slightly reduced brake thermal efficiency and increased smoke, hydrocarbon, carbon monoxide and reduced NO x emissions compared with diesel-only operation. The investigation showed that the B20 biodiesel blend of Marotti oil with diesel produced better performance in terms of higher brake thermal efficiency, lower specific fuel consumption and comparatively lower emissions compared to the other blend ratios considered.  相似文献   

17.
Contributing to extant discourses about corporate environmental advocacy, this paper argues that corporations can embed discursive rhetorical strategies in material places and spaces. This argument contributes to environmental communication by bridging divisions between discursive and materialist approaches to corporate rhetoric. Corporate materiality is realized in the study of Rio Tinto Kennecott (RTK) at places of corporate community where RTK enunciates a dominant environmental discourse about the necessity of the Bingham Canyon Mine through strategies such as the technological shell game, the hypocrite's trap, and corporate heterotopia, which are made manifest materially alongside cultural values such as epistemic trust, technological progress, community, and home. Using participatory critical rhetoric as a methodology, I analyse RTK's material rhetoric at the Natural History Museum of Utah, the Rio Tinto Soccer Stadium, and the Daybreak suburban community. This case study reveals that corporations are assemblages that assert many different, and sometimes competing, arguments that can deflect environmental criticism, materially.  相似文献   

18.
应用平衡分配法建立长江水系沉积物金属相对质量基准   总被引:9,自引:0,他引:9  
在不同的条件下,沉积物可成为环境中污染物的“源”或“汇”,而受污染的沉积物会对水生生物带来危害。因此,需要制定沉积物质量基准(SQC),以此作为评价沉积物污染及其生态效应的基础。在过去的几年中,对利用平衡分配法来建立SQC的方法进行了广泛的研究,并被认为是最有效的方法之一。采用平衡分配法,初步建立了长江水系8种重金属及类金属(Cu, Zn, Cd, Pb, Ni, Fe, Hg,As)的沉积物相对质量基准。结果表明,上述重金属及类金属的SQC在从长江上游到下游,总体趋势上呈降低的分布特征,并由于地域环境条件的不同,存在着高SQC值单元及低SQC值单元。得出的SQC与国内已有的SQC具有可比性,但高于美国国家环保局提出的SQC,主要是由于采用平衡分配法建立的SQC是一种数值型的基准值,缺乏生物效应的校正。因此,在将其应用到沉积物污染状况评价之前,还需要进行深入的研究工作,特别是毒理学试验。  相似文献   

19.
A sward will often have significant amounts of soil adhered to the vegetation surfaces which will be ingested by grazing animals. If the soil is contaminated by radioactive fallout then it can serve as a dietary source of radionuclides, in addition to any root uptake by the plants. This study is an attempt to quantitatively assess the importance of soil adhesion as a source of radiocaesium to sheep using the RUINS model which simulates radiocaesium transfer in grazing systems.The method of simulating the contamination of vegetation surfaces used by the RUINS model is described, and the importance of the availability of radiocaesium associated with adhered soil relative to plant incorporated radiocaesium discussed. Two sets of simulations are presented: one in which the soil is treated as a medium providing a uniform availability of radiocaesium, and the second in which account is taken of the partitioning of radiocaesium in the soil between ‘fixed’ and ‘labile’ phases.The results demonstrate that, because of the reduced absorption in the gut of radiocaesium associated with soil, animals grazing pastures with significant amounts of radiocaesium associated with adhered soil will not be as contaminated as radiocaesium activity concentrations measured in bulk vegetation samples would suggest. Therefore, the extent of soil adhesion needs to be considered if predictions of radiocaesium contamination of animal products are to be made on the basis of measured activities of sampled vegetation. However, soil adhesion is unlikely to be a significant dietary source of available radiocaesium, unless the soil concerned exhibits an unusually high bioavailability of radiocaesium. Moreover the simulation results indicate that differences in availability between soil types observed experimentally are consistent with the partitioning between fixed and labile soil compartments made by the RUINS model.  相似文献   

20.
We can enhance our quality of life and reduce environmental impacts by making improvements in textile product design. By thinking about the environment when we design, choose and use technology, we can play an important part in building a better world for the future. If we are going to live in a sustainable way, the technology that we use has to be sustainable.

This paper provides an insight into how the design of textile products could provide for a more sustainable future. It describes a design concept for an ecological relaxing textile that uses photovoltaic cells to collect and store solar energy and to power an electronic relaxing system. This design may help improve our quality of life now and in the future.

The raw materials and processes, the electronic devices and the dimensions of solar energy for this application are analysed from an environmental perspective. The solar relaxing textile can facilitate our daily life by providing increased comfort and well being, and also acts as an indirect message to use renewable energy within textile support, in order to preserve our ecology.  相似文献   

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