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Rising fuel prices and concern over emissions are prompting automakers and legislators to introduce and evaluate "clean vehicles" throughout the United States. Hybrid electric vehicles (HEVs) are now on the roads, electric vehicles (EVs) have been test marketed, and niche vehicles such as high-fuel-economy microcars are being considered for introduction. As these vehicles proliferate and mature, they will eventually reach their end of life (EOL). In the United States, an extensive recycling infrastructure exists for conventional, internal combustion engine (ICE) vehicles. Its primary constituents are the disassembler and the shredder. These industries, as well as battery recyclers, are expected to play integral roles in the EOL processing of clean vehicles.
A model of the automobile-recycling infrastructure and goal programming techniques are used to assess the materials streams and process profitabilities for several different clean vehicles. Two-seat EVs with lead-acid or NiMH batteries are compared with two- and four-seat HEVs and microcars. Changes to the nonferrous content in the vehicle bodies are explored and compared for the effect on processing profit-ability. Despite limitations associated with the linearity of goal programming techniques, application of this tool can still provide informative first-order results. Results indicate that although these clean vehicles may not garner the same profit levels as conventional ICE vehicles, they are profitable to process if there are markets for parts and if there are sufficient quantities of nonferrous materials. 相似文献
A model of the automobile-recycling infrastructure and goal programming techniques are used to assess the materials streams and process profitabilities for several different clean vehicles. Two-seat EVs with lead-acid or NiMH batteries are compared with two- and four-seat HEVs and microcars. Changes to the nonferrous content in the vehicle bodies are explored and compared for the effect on processing profit-ability. Despite limitations associated with the linearity of goal programming techniques, application of this tool can still provide informative first-order results. Results indicate that although these clean vehicles may not garner the same profit levels as conventional ICE vehicles, they are profitable to process if there are markets for parts and if there are sufficient quantities of nonferrous materials. 相似文献
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Mariana Angoa-Pérez Michael J. Kane Denise I. Briggs Dina M. Francescutti Donald M. Kuhn 《Journal of visualized experiments : JoVE》2013,(82)
Obsessive-compulsive disorder (OCD) and autism spectrum disorders (ASD) are serious and debilitating psychiatric conditions and each constitutes a significant public health concern, particularly in children. Both of these conditions are highlighted by the repeated expression of meaningless behaviors. Individuals with OCD often show checking, frequent hand washing, and counting. Children with ASDs also engage in repetitive tapping, arm or hand flapping, and rocking. These behaviors can vary widely in intensity and frequency of expression. More intense forms of repetitive behaviors can even result in injury (e.g. excessive grooming, hand washing, and self-stimulation). These behaviors are therefore very disruptive and make normal social discourse difficult. Treatment options for repetitive behaviors in OCD and ASDs are somewhat limited and there is great interest in developing more effective therapies for each condition. Numerous animal models for evaluating compulsive-like behaviors have been developed over the past three decades. Perhaps the animal models with the greatest validity and ease of use are the marble burying test and the nestlet shredding test. Both tests take advantage of the fact that the target behaviors occur spontaneously in mice. In the marble burying test, 20 marbles are arrayed on the surface of clean bedding. The number of marbles buried in a 30 min session is scored by investigators blind to the treatment or status of the subjects. In the nestlet shredding test, a nestlet comprised of pulped cotton fiber is preweighed and placed on top of cage bedding and the amount of the nestlet remaining intact after a 30 min test session is determined. Presently, we describe protocols for and show movie documentation of marble burying and nestlet shredding. Both tests are easily and accurately scored and each is sensitive to small changes in the expression of compulsive-like behaviors that result from genetic manipulations, disease, or head injury. 相似文献
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Collection and treatment of waste from electrical and electronic equipment (WEEE) is regulated in the European Union by the WEEE Directive. Producers are responsible for take‐back and recycling of discarded equipment. Valuable materials are, however, at risk of “getting lost” in current processes. Thus, strategies to minimize losses are sought after. The material hygiene (MH) concept was introduced to address this issue. Structural features, which are important for the outcome of reuse, recovery, and recycling, were investigated in an earlier field study of discarded dishwashers. It was proposed that a prestep, manual removal of copper prior to shredding could increase the purity of recovered material fractions. This article builds on the field study and theoretical reasoning underlying the MH concept. Dishwashers are assumed to be designed for disassembly when the prestep is introduced. A limited life cycle assessment was performed to determine whether the proposed prestep may be environmentally beneficial in a life cycle perspective. Two alternatives were analyzed: Case 1: the current shredding process. Case 2: prestep removal of copper before shredding. Targeted disassembly prior to shredding may reduce the abiotic depletion and global warming potential in a life cycle perspective. The prestep results in increased copper recovery, but, more important, copper contamination of the recovered steel fractions is reduced. The results also highlight the importance of minimizing energy consumption in all process stages. 相似文献
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Methods for detection of anxiolytic-like behavioral effects of serotonin uptake inhibitors are limited. The present study introduces a new quantitative method that permits dose-effect analysis of these compounds. Male NIH Swiss mice were given 60-min access to a piece of cotton gauze and the amount of material not torn into nesting material was weighed. Other groups of mice were individually placed in containers with 20 marbles resting on top of sawdust bedding. The number of marbles buried (2/3) by sawdust after 30 min was counted. Mice were first placed on a 6-rpm rotorod and the number of mice falling off twice in 2 min was measured. Serotonin uptake inhibitors (clomipramine, citalopram, fluoxetine, and venlafaxine) dose-dependently suppressed nestlet shredding and marble burying at doses that were generally without effect on rotorod performance. The amine-based antidepressant agents imipramine and desipramine as well as the selective norepinephrine transport inhibitor nisoxetine produced similar qualitative effects on these behaviors. Anxiolytics (chlordiazepoxide, bretazenil, buspirone, and pentobarbital) produced effects in the nestlet assay that were similar to those reported using another anxiolytic assay in mice (punished responding), whereas these compounds were not active at non-motor-impairing doses in the marble burying assay. The antipsychotic agents chlorpromazine and risperidone generally demonstrated suppression of nestlet shredding and marble burying at doses that impaired rotorod performance. Although d-amphetamine suppressed nestlet shredding and marble burying at doses without effect on the rotorod, d-amphetamine but not fluoxetine stimulated locomotor activity. Both nestlet shredding and marble burying behaviors were generally consistent across five consecutive experimental sessions and fluoxetine did not produce any systematic trends over repeated testing. The methods should have utility in defining pharmacological effects of these compounds in vivo. Moreover, these data may be useful in the context of other behavioral effects when assessing the relevance of a compound for its potential therapeutic potential as an anxiolytic (nestlet shredding) or as an anti-obsessive-compulsive disorder agent (marble burying). 相似文献
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The freshwater snail Melanopsis praemorsa is veryabundant inoases of the Judean Desert. To determine its role as littershredder, experiments were carried out in Nahal Arugot. Boxeswereplaced in the stream (29 °C), each containing 1 g ofdrywillow leaves together with one snail; or six snails.With one snail per box, dry leaf weight after two daysdeclined to72% of the initial dry weight, after twelve days to 58% andaftereighteen days to only 40%. During this period thesnails in the experiment increased by 12% in shell-height, by20%in snail weight (including the shell), by 33% in live freshbiomass. Each snail consumed about 10 mg litter per day.With six snails per box, dry leaf weight after two daysdeclined to62% of the initial dry weight and after twenty days to only15%.In natural populations where density was 44 snails per quadrat(of25×25 cm), 1 g of dry leaves was reduced to 25%theinitial weight within three days. Overall plant cover along a600×10 m stretch of the stream was found to be45%, ofwhich 65% was willow. During one year about 1 kg litter wasshedper m2 willow; by extrapolation, this would be about1800 kglitter throughout the stretch. Much of this vast amount oflitteris consumed by the snails, who thereby reduce summer dammingof theoasis. Our study suggests that M. praemorsa, a generalistfeeder, may be a major litter shredder in certain desert oasisecosystems. 相似文献
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