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31.
Hydrogasification of a coal/polyethylene mixture was carried out using a low concentration of polyethylene in the samples with the aim of industrial application. Coal/polyethylene mixtures in the ratio of 90:10 and 75:25 were used in this study. A hydrogasification experiment was conducted using a unique batch reactor at 1073 K under a 7.1 MPa hydrogen atmosphere. The reaction time varied from 1 to 80 s. The results revealed a methane yield from the mixtures that was noticeably greater than the values calculated from experimental results obtained from coal and polyethylene respectively, assuming no mutual influences. A significant synergistic effect was observed even when the polyethylene content was as low as 10 %. It is suggested that there might be an advantage in hydrogasification processes if waste plastics are mixed with coal, such content being practically assumed.  相似文献   
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33.
Nakao T  Aozasa O  Ohta S  Miyata H 《Chemosphere》2006,62(3):459-468
We investigated combustion in a small home waste incinerator and analyzed both flue gas and residual ash for formation of the dioxin-related compounds polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, and coplanar polychlorinated biphenyls and their precursors polychlorinated benzenes, polychlorinated phenols, polychlorinated diphenyl ethers, and polychlorinated biphenyls. Particularly, we investigated the effect of the incinerated material's composition on both the congener ratios of released compounds and the total concentration of all congeners of each compound. Eight different samples were prepared for incineration with four samples consist entirely paper, dead leaves, natural wood, or building materials. The remaining four samples contained mostly paper, but also other components such as fiber, non-chlorine-containing plastics, chlorine-containing plastics, and copper electric wire. The presence of non-chlorine-containing plastic in combustion samples did not increase overall dioxin or dioxin-precursor emissions. In contrast, chlorine-containing plastic resulted in a several-fold increase in total polychlorinated dioxins released, in both flue gas and residual ash. Copper wire resulted in a further several-fold increase in total polychlorinated dioxins and dioxin precursors released, with one exception: the addition of chlorine-containing plastic resulted in a many-fold increase in polychlorinated biphenyls, but only a modest further increase ( approximately 52%) with the further addition of copper. Homologue ratios tended toward higher-chlorine compounds as chlorine-containing plastic and Cu were added, but the results were far from uniform. Our results show that toxic dioxin release from small home waste incinerators must be considered significant, especially if even small amounts of chlorine-containing plastics or copper are burned.  相似文献   
34.
The integrated model is composed of two basic parts: one is a reaction rate model of biodegradation in combination with bioenergetics and the other is a thermal engineering model of energy flow and balance in the bioreactor. Integrating these models provides possibility to estimate microbial activity using time course of physicochemical parameters such as bed temperature, bed weight, and/or C02 concentration during decomposition.  相似文献   
35.
Norovirus GII.3, GII.4, and GII.17 were detected using pyrosequencing in sewage and oysters in January and February 2015, in Japan. The strains in sewage and oyster samples were genetically identical or similar, predominant strains belonging to GII.17 Kawasaki 2014 lineage. This is the first report of GII.17 Kawasaki 2014 in oysters.  相似文献   
36.
GIS支持下的滑坡空间预测与危险等级划分   总被引:5,自引:0,他引:5  
以日本早池峰山地域为研究对象,借助航片、TM影像、数字化地图以及各种统计资料和现有专题图等主要数据,利用美国MicroImage公司开发的TNTmips地理信息系统,将数量化理论与地理信息系统紧密结合,对区域滑坡进行了空间预测和危险等级划分.提取并计算了滑坡以及包括坡度、坡向、海拔、坡面倾斜类型、降雨、植被、土壤和地质等8个滑坡影响因子,得到了滑坡及其影响因子的空间分布图.在此基础上,抽取372个样本,应用数量化理论对这些样本进行了分析,建立了区域滑坡预测模型.该模型经研究区域共1296384个样本检验,模型预测精度达80.49%.最后,以滑坡发生概率为基准,对滑坡危险等级进行了划分.  相似文献   
37.
The desert environmental changes in the source areas of dust storms occurring in Xinjiang are discussed based on the climate changes and the impacts of human activities in Xinjiang during the past 50 years. The results show that the climate in Xinjiang is changing from a warm-dry type to a warm-wet one. The warm-wet climate has been obvious since the mid-1970's, and especially the sensitivity of the regional climate change in this arid area is obviously revealed by many factors, such as the characteristics of the local climate change in south Xinjiang and north Xinjiang, the difference of climate change in the alpine zones and the basins, and the change of areas of the waters bodies. Furthermore, these factors also reveal the difference in the regional climate change between Xinjiang and central and eastern areas of China. The occurrence and development of dust storms are directly affected by the precipitation, air humidity, status of underlying surface, etc. in the arid areas. The frequency and intensity of dust storms are closely related to the natural conditions, changes of climate and desert environment, as well as the dynamic conditions (i.e., weather systems) in the source areas of dust storms. Therefore, global warming is one of the main causes resulting in the degradation of the ecological environment and the frequent occurrence of natural disasters, especially the disasters of sand drift and dust storms in the arid areas since the late-1980's, which reveals that the inland arid areas are sensitive regions to climate changes.  相似文献   
38.
First, this paper evaluates the current building material stock and future demolition waste for urban residential buildings in the cities of Jakarta and Bandung using a material-flow analysis. The actual on-site building measurements were conducted in Jakarta (2012) and Bandung (2011), focusing particularly on unplanned houses, to obtain building material inventory data. A total of 297 houses were investigated in Jakarta, whereas 247 houses were measured in Bandung. Second, this paper analyses the embodied energy and CO2 emissions of building materials through an input–output analysis. The results show that, overall, the total material input intensity for the houses is 2.67 ton/m2 in Jakarta and 2.54 ton/m2 in Bandung. Two scenarios with zero and maximum reuse/recycling rates were designed to predict future demolition waste and the embodied energy/CO2 emissions of building materials in Jakarta. Closed- and open-loop material flows were applied. If the maximum reuse/recycling rates are applied to the closed- and open-loop material flows in Jakarta, then it would become possible to not only decrease the final disposal waste (from 123.9 to 2.1 million ton) but also reduce the corresponding embodied energy (from 247.8 to 192.1 PJ) and CO2 emissions (from 24.3 to 19.2 million ton CO2-eq) compared with the zero reuse/recycling scenario from 2012 to 2020.  相似文献   
39.
In sustainability science (SS), it is difficult to identify what needs to be solved, and it is also not clear how to solve the problems that are identified. There has been no consensus on the underlying question of “What is structuring knowledge in SS?” This paper focuses on knowledge structuring accompanied by supporting of thinking. It addresses the key challenges associated with knowledge structuring in SS, identifies the requirements for the structuring of knowledge, proposes a reference model, and develops an ontology-based mapping tool as a solution to one layer of the reference model. First, we identify the important requirements for SS knowledge structuring. Second, we develop a reference model composed of five layers based on three of the requirements. Third, we develop an ontology-based mapping tool at Layer 2 of the reference model for meeting the two major challenges for SS, namely, identifying what problems should be addressed in SS itself and proposing solutions for those problems. The tool is designed to store and retrieve information regarding SS, to provide access to a prototype ontology for SS, and to create multiple maps of conceptual chains depending on a user’s interests and perspectives. Finally, we assess whether the developed tool successfully realizes the targeted part of the reference model for SS by examining the tool’s conformity to the reference model, as well as its usability, effectiveness, and constraints. Although several issues were identified in the prototype ontology and the mapping tool, the study concluded that the mapping tool is useful enough to facilitate the function of Layer 2. In particular, the mapping tool can support thinking about SS from the viewpoint of: (a) finding new potentials and risks of technological countermeasures studied in SS; (b) helping users to get a more comprehensive picture of problems and their potential solutions; and (c) providing an effective opportunity to come up with new ideas that might not be thought of without such a tool.  相似文献   
40.
Phylogenetic relationships among vestimentiferans in the family Lamellibrachiidae collected from ten sites in the western Pacific were analyzed on the basis of the nucleotide sequence of part of a mitochondrial gene for cytochrome oxidase I. The 103 individuals analyzed were tentatively classified into five species: namely, Lamellibrachia satsuma, three tentative species inhabiting Japanese waters and one tentative species from the Manus Basin. Phylogenetic analysis of the four tentative species, L. satsuma, and two lamellibrachiids, whose sequences had been reported previously, namely L. columna from the Lau Basin and L. barhami from the Oregon Margin and the Middle Valley, revealed that the lamellibrachiids from Japanese waters were not monophyletic. While two tentative species from Japanese waters and L. columna formed a monophyletic group, the other tentative species from Japanese waters was closely related to the tentative species from the Manus Basin. L. satsuma was shown to be phylogenetically distinct from other lamellibrachiids of the western Pacific. A lamellibrachiid that had been collected from the Nikko Seamount was also demonstrated to be L. sastuma.  相似文献   
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