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61.
At various levels of environmental policy making there is a demand to translate polluting emissions into monetary units. In the so-called reduction cost approach, based upon policy targets, polluting emissions are expressed in monetary terms by determination of the marginal unit reduction cost at the emission target level. This approach provides shadow prices for emissions by which it can be established whether a certain measure or technology belongs to the most efficient set of measures by which the policy targets can be reached. This article argues that, if clear (generic) government targets such as national emission reduction targets exist for an emission, shadow prices derived by this method are to be preferred to shadow prices derived by other methods for decisions at the project (implementation) level. By application of the reduction cost approach, implementation decisions can be made that are both cost-effective and consistent with government policy. 相似文献
62.
Assessment of the Automobile Assembly Paint Process for Energy, Environmental, and Economic Improvement 总被引:1,自引:0,他引:1
《Journal of Industrial Ecology》2004,8(1-2):173-191
A coat of paint adds considerable value to an automobile. In addition to consuming up to 60% of the energy needed by automobile assembly plants, however, the painting process also creates both economic and environmental impacts. This study investigated the degree of cost and environmental impact improvement that can be expected when modifications are considered for existing paint processes through heat integration. In order to accomplish this goal, a mathematical model was created to describe the energy use, costs, and environmental impacts from energy consumption in an automobile assembly painting facility. The model agrees with measured energy consumption data for process heating and electricity demand to within about 15% for one Michigan truck facility from which model input parameters were obtained. Thermal pinch analysis determined an energy conservation target of 58% of paint process energy demand. A heat exchanger network optimization study was conducted in order to determine how closely the network design could achieve this target. The resulting heat exchanger network design was profitable based on a discounted cash flow analysis and may achieve reductions in total corporate energy consumption of up to 16% if implemented corporatewide at a major automobile manufacturer. 相似文献
63.
Biology incorporated into other disciplines is often distorted, alarmingly so in some areas of medicine. Together with other forms of bias, this may have detrimental effects for patients depending on medical research for their health. A case study concerning omeprazole (Losec), one of the acid-suppressive drugs against gastric ulcers, and NSAIDs, non-steroid anti-inflammatory drugs, confirms that distorted biology together with biased health care policies foster disasters in current biomedicine and medical practice. In our country, The Netherlands, omeprazole is presumably the most commonly used medication. NSAIDs are also used in large quantities, increasingly since they have become available as analgesic over-the-counter drugs. Unofficial and official sources tend to inform the general public that the drugs promote human health. We argue that their being used on a massive scale is actually a medical disaster. The health of many patients would be served better if the drugs they take were replaced by proper forms of diet, but the pharmaceutical industry, the most potent force affecting medication policies, appears to prevent a shift in the balance from over-medicalization towards healthy life styles. The shift should come from government agencies responsible for regulation in the medication market. Policies of these agencies are now a dismal failure. 相似文献
64.
65.
作为名贵传统药材,冬虫夏草的研究方兴未艾。无性型的确定、学名的变更和"一种真菌一个名称"确定了冬虫夏草菌为Ophiocordyceps sinensis;独特的分布、悠久的历史、公众的认可及地方经济的重要作用等被推荐为"国菌";"虫草产业发展金湖宣言"从产、学、研倡议"尊重科学、利好产业"的发展思路。随着科学研究深入和产业技术发展,冬虫夏草培植获得成功。本专刊对冬虫夏草培植相关基础研究和关键技术进行了总结,对寄主昆虫选育及规模化饲养关键技术到冬虫夏草菌菌种筛选、侵染途径和培植以及培植产品与野生冬虫夏草化学成分和蛋白质谱比较等进行了论述。冬虫夏草培植的成功,不论从科学还是产业的角度,都具有里程碑式的意义。 相似文献
66.
新兴遗址第1地点位于吉林省汪清县嘎呀河支流前河北岸的二级阶地,2018年调查发现,2019年对该地点进行了复查和试掘,试掘面积14 m2。采集和试掘发现标本131件,以石制品为主,包括石核、石片、石叶、细石叶、刮削器、砍砸器、尖状器、手斧和磨制石器,此外还发现有少量夹砂陶片。总体来看该遗址包含旧石器和新石器两期文化遗存,其中旧石器时代遗存以石叶和细石叶为主要技术特征,石制品原料以硅质页岩和黑曜岩为主,根据石制品技术特征和地层堆积情况判断,年代与临近的黑龙江穆棱市康乐遗址年代相近,为距今10000年前后;新石器时代文化遗存属图们江流域金谷文化范畴。 相似文献
67.
《Chronobiology international》2013,30(4):521-537
A recent worldwide trend in chemical and petrochemical industries is to extend the duration of shifts. Optimization of the labor force to reduce costs is one reason to increase the length of working time in a shift. Implementation of 12h shifts is a controversial decision for managers and scientists. Literature reviews show alertness is lower during the nighttime hours, and sleep duration is reduced and worse during the daytime. The main objective of this study was to evaluate the impacts of 12h shifts on alertness and sleep. To evaluate the duration and quality of sleep and alertness during work, 22 male shift workers on a continuous rotating schedule at a petrochemical plant completed activity logs and estimated alertness using analog 10-cm scales for 30 consecutive days, three times (at 2h, 6h, and 10h of the shift) every work shift. Statistical tests (analysis of variance [ANOVA] and Tukey) were performed to detect differences between workdays and off days. The shift schedule was 2 days/3 nights/4 off days, followed by 3 days/2 nights/5 off days, followed by 2 days/2 nights/5 off days. Sleep duration varied significantly (p <. 001) among the work shifts and off days. Comparing work nights, the shortest mean sleep occurred after the second night (mean = 311.4 minutes, SD = 101.7 minutes), followed by the third night (mean = 335.3 minutes, SD = 151.2 minutes). All but one shift (sleep after the first work night) were significantly different from sleep after the first 2 workdays (p <. 002). Tukey tests showed no significant differences in sleep quality between workdays and nights, with the exception of sleep after the third day compared to sleep after night shifts. However, significant differences were detected between off days and work nights (p <. 01). ANOVA analysis showed borderline differences among perceived alertness during day shifts (p =. 073) and significant differences among the hours of theshifts(p =. 0005), especially when comparing the 2nd hour of the first day with the 10th hour of all the day shifts. There were no significant differences in perceived alertness during night work among the first, second, and third nights (p =. 573), but there were significant differences comparing the times (2nd, 6th, 10th hour) of the night shifts (p ≤. 001). The evaluation of sleep (duration and quality) and level of alertness have been extensively used in the literature as indicators of possible performance decrements at work. The results of this study show poorer sleep after and significantly decreased alertness during night work. Shifts of 12h are usually implemented for technical and economic reasons. These results point out the necessity of a careful trade-off between the financial and technical gains longer shifts might bring and the possible losses due to incidents or accidents from performance decrements during work. (Chronobiology International, 17(4), 521–537, 2000) 相似文献
68.
Lignin genetic engineering 总被引:5,自引:0,他引:5
Alain M. Boudet Jacqueline Grima-Pettenati 《Molecular breeding : new strategies in plant improvement》1996,2(1):25-39
Although lignins play important roles in plants, they often represent an obstacle to the utilization of plant biomass in different areas: pulp industry, forage digestibility. The recent characterization of different lignification genes has stimulated research programmes aimed at modifying the lignin profiles of plants through genetic engineering (antisense and sense suppression of gene expression). The first transgenic plants with a modification of monomeric composition of lignins and lignin content have been recently obtained. Down regulation of the OMT gene induces dramatic reduction of syringyl units. CAD down regulated plants exhibit a unusual red phenotype associated with the developing xylem and several chemical modifications of their lignins including an increase in cinnamaldehydes in the polymer structure. Interestingly this novel lignin is removed more easily during the pulping process. In both OMT and CAD down regulated plants no changes in phenotypic characteristics such as growth architecture and morphology were observed. More recent experiments have shown that a reduction of CCR activity determines specific changes in the coloration of the xylem area suggesting significant chemical modifications which are currently being studied.These different results show that it is possible to manipulate lignins through targeted genetic transformation of plants and that lignins exhibit a relative flexibility of their chemical structure. Future developments should probe the impact of down regulating the expression of other recently characterized lignification genes such as F5H and CCoAOMT and also of a combination of genes in order to tailor lignins more adapted to specific purposes. In addition to biotechnological applications which should provide important economical benefits for utilization of wood in the pulp industry, genetic engineering of lignins offer very promising perspectives for the understanding of lignin synthesis, structure and properties. 相似文献
69.
王府井东方广场遗址出土石制品共计1098件,主要来自下文化层。除石锤、石砧和人工石块外,其他石制品的原料几乎全部为黑色燧石。石制品普遍较小,主要为小型和微型。石核数量很少,但石片占石制品总数的一半还多。碎屑在探方中的几个区域密集分布。石器加工精致,刃缘大部分都比较平齐且其上的修疤排列均匀、整齐,尤其表现在端刮器上。原料、类型与技术特点表明,东方广场遗址石制品组合属于中国旧石器时代晚期的以石片为主要特征的文化系列。这一文化系列与周口店北京猿人遗址、周口店第15地点、许家窑遗址等有较多的相似性,推测东方广场石制品组合是由中国旧石器时代早期和中期石器工业演变而来。 相似文献
70.
Floyd Green 《Biotechnic & histochemistry》2000,75(4):167-175
The synthetic dye industry is traced from its inception in England in 1856 to the European Continent and finally to the United States. The primitive state of this industry in America prior to World War I is described as is the desperate effort to develop the neglected technology once imports were difficult to obtain. Topics include biological stains, formation of the Biological Stain Commission (BSC), pioneers in the industry, dye shortages after World War II, formation of the Environmental Protection Agency (EPA), the decline of the domestic dye industry after the EPA was instituted, and the present state of the domestic dye industry. 相似文献