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261.
Ivan Jovanović Marija Savić Živan Živković Bojan S. Boyanov Alexander Peltekov 《Environmental Modeling and Assessment》2016,21(4):455-465
This paper presents a mathematical model for solving the blending composition problem used in the zinc smelting process. The model proposes an objective function maximizing profit in terms of the total income from the sale of zinc on the market and the cost of producing zinc. In addition to the constraints contained in the basic mathematical model, the constraints, which are in accordance with the specific production process of zinc and environmental requirements, are developed. This paper proposes a model that can align three contradictory demands (technological, economic, and environmental) present in zinc production. The results, obtained by numerical experiments, confirm the assumption that it is possible to assemble such an optimal batch that will “reconcile” all contradictory demands. This model can be applied to other similar processes of production with minor changes. 相似文献
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Alexander C. Wagenaar 《Journal of Safety Research》1985,16(1):9-21
Research has indicated that laws requiring use of restraint devices for young children traveling in automobiles have had significant effects in increasing restraint use and reducing crash-related childhood injuries. This study examined dimensions along which the effectiveness of Michigan's April 1982 mandatory child restraint law varied. All children involved in motor vehicle crashes in Michigan from January 1978 through December 1982 were analyzed using multivariate intervention analysis methods. Research revealed that the effectiveness of the law in reducing childhood injuries was primarily due to reductions in less severe injuries occurring in crashed vehicles experiencing low to moderate levels of damage. Furthermore, the mechanism for the law's effects was not simply an increase in restraint use. In addition, the number of children riding in the more dangerous front-seat and cargo-area positions apparently decreased following implementation of the law, with children increasingly riding in the safer rear-seat position. 相似文献
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流域的可持续管理:国际多个流域的案例研究 总被引:3,自引:0,他引:3
Walter Wagner James Gawel Hiroaki Furumai Marcelo Pereira de Souza Denilson Teixeira Leonardo Rios Shinichiro Ohgaki Alexander J.B.Zehnder Harold F. Hemond 《Ambio-人类环境杂志》2002,31(1):2-13
全球淡水资源正在不断受到污染和亏耗,威胁着可持续发展及人类和生态系统的健康.本文通过美国、日本、瑞士和巴西四个不同流域的案例研究,阐述了与淡水资源密切相关的可持续发展中的缺陷,指明了水资源可持续管理的总体方向.由于近几十年来人口的增长和经济的发展,每个流域的水质、流量和生物资源量都在下降.但是对于不同的流域来说,与水有关的这些问题的严重程度和文化观念大不相同,因而形成各自独特的水资源管理政策.在工业化国家,例如美国、瑞士和日本,这类政策允许采用资金密集型和能源密集型技术,使得这些国家在满足其水资源需求的同时还能尽量降低人类健康风险.然而,从可持续发展的观点看,以有限的自然资源为基础制定的这类政策,并非长久之计.对于新兴工业化国家(如巴西)来说,昂贵的水资源管理技术在经济上常常行不通,因而限制了新兴工业化国家和发展中国家对发达国家提供的技术的利用程度.要实现水资源的可持续管理,发达国家、新兴工业化国家和发展中国家都需要经历一个学习的过程,同时还需要遵循本文介绍的可持续发展的通用原则. 相似文献
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Dr. Michael Hirsch Zev Josefsberg Alexander Schoenfeld Athaliah Pertzelan Paul Merlob Sara Leiba Gertrude Kohn Jardena Ovadia Ernesto Lubin Zvi Laron 《黑龙江环境通报》1990,10(8):491-496
Intrauterine diagnosis of congenital hypothyroidism was established on the basis of TSH concentration in amniotic fluid in the 22nd week of gestation for the offspring of a couple both known to have an iodide organification defect. Prenatal treatment consisted of intramniotic injections of 500 meg Na-1-thyroxine, which was administered from the first amniocentesis until one week before delivery. Following delivery, the diagnosis was confirmed by the elevated level of TSH, 60-5 uU/ml, and a gradual decrease of fT4 to 0·8 ng/ml. Regular substitution therapy was commenced on the third day of life. The normal shape and location of the thyroid gland was demonstrated by Technetium scintiscan. At 18 months the infant revealed no significant deviation from normalcy in growth or mental capacity. This experience indicates that testing of amniotic fluid for TSH in the 22nd week of gestation can be diagnostic for congenital primary hypothyroidism. Furthermore, it is suggested that the treatment approach described is warranted in all cases in which there is a high risk of congenital primary hypothyroidism. 相似文献
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Dimethyl trisulphide has been found in samples of potable water in concentrations ranging from 5 to 250 ng liter ?1. The presence of dimethyl trisulphide in concentrations greater than 10ng liter?1 was associated with an objectionable odour in water samples. The odour intensity and dimethyl trisulphide concentrations increased in distribution mains with increasing distance from a holding reservoir. The mechanism of formation of dimethyl trisulphide in the water supply is not yet known. 相似文献