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1.
Ryu C Phan AN Yang YB Sharifi VN Swithenbank J 《Waste management (New York, N.Y.)》2007,27(6):802-810
Recent developments in national recycling and re-use programmes for municipal waste have led to segregation of an increasing proportion of waste to enhance material recovery. Several of the segregated streams contain materials that can not viably be re-used or recycled but can be used for energy recovery. In this study, the combustion of cardboard and waste wood was investigated in a small-scale packed bed reactor in order to provide fundamental data for the design/operation of moving bed furnaces. Key parameters of combustion including the ignition and burning rates were evaluated for various air flowrates and compared to the modelling results. Two successive stages of combustion were identified for both samples: the propagation of ignition front into the bed and combustion of the fuel above the ignition front. The burning rate of cardboard reached a peak of about 300 kg/m(2)h at the air flowrate of 936 kg/m(2)h and decreased at higher air flowrates. For waste wood, both the ignition and burning rates increased in the tested range of the air flowrate up to 702 kg/m(2)h, of which the values were very close to those for the cardboard. The model prediction was in good agreement with the test results for waste wood. However, the burning rate for cardboard was under-predicted due to strongly irregular shapes of the fuel. 相似文献
2.
Dry weight (DW), oxygen consumption, ammonia-N excretion, proximate biochemical composition (total protein, carbohydrate,
lipid, water and ash), and energy content (estimated from biochemical composition and by wet combustion) were determined in
early developmental stages of cultured Farfantepenaeus paulensis. Pooled samples from embryonic, larval and postlarval stages (at 26 ± 1 °C and 34 ± 1‰) were used for measurements. The study
focused on physiological and biochemical processes during transitional periods of ontogeny, such as hatching, lecithotrophic
and planktotrophic stages, metamorphosis, and the attainment of a benthic existence in postlarva. DW showed higher increment
between protozoea I (PZ I) and mysis I (M I) than in the next mysid and postlarval stages. Individual rates of oxygen consumption
and ammonia-N excretion increased, while weight-specific rates presented significant reduction throughout development. Higher
weight-specific oxygen consumption was registered in nauplius III (N III) and PZ I, following a decrease in subsequent stages.
Postlarval stages PL V–VI and PL X–XII exhibited the lowest values among the stages studied. Weight-specific excretion was
high in N III and protozoeal stages, with maximum values in PZ II, while the following stages were marked by lower rates.
O:N ratios indicated higher protein catabolism in the stages between egg and M I and a shift to more lipid utilization close
to metamorphosis. Water content was higher in the protozoeal stages and decreased afterwards. Higher percentages of protein,
lipid and carbohydrate (%DW) were observed in egg and nauplius stages. Protein and lipid decreased from the egg through the
naupliar and protozoeal stages, rising again in mysis stages. Lipid content (%DW) decreased in PL V–VI and PL X–XII. Lipid:protein
ratios showed an increase of the importance of lipid between PZ III and M II. Carbohydrates represented a minor fraction of
body composition, and ash percentages increased from egg to a maximum in PZ II, decreasing in subsequent stages. Energy content
determined by wet combustion or calculated by energy equivalents presented the same trend throughout development, varying
similarly to protein. Protein was the main energy contributor to body energy in all stages, while the importance of lipid
was higher in egg and early naupliar stages. Trends observed in metabolic rates and body composition may be associated to
morphological and behavioral changes during the early stages of penaeid development, such as the transition from herbivory
to omnivory, and the adoption of a benthic existence. Different ontogenetic energy strategies contribute to succeed through
such diverse type of development.
Received: 4 July 2000 / Accepted: 6 December 2000 相似文献
3.
In a laboratory-scale combustion reactor, flue-gas samples were collected at two temperatures in the post-combustion zone, 700 °C and 400 °C, using two different water-cooled sampling probes. The probes were the cooled probe described in the European Standard method EN-1948:1, referred to as the original probe, and a modified probe that contained a salt/ice mixture to assist the cooling, referred to as the sub-zero probe. To determine the efficiency of the cooling probes, internal temperature measurements were recorded at 5 cm intervals inside the probes. Flue-gas samples were analyzed for polychlorinated dibenzo-p-dioxin and dibenzofurans (PCDD/Fs). Samples collected at 700 °C using the original cooling probe showed higher concentrations of PCDD/Fs compared to samples collected using the sub-zero probe. No significant differences were observed between samples collected at 400 °C. The results indicated that artifact formation of PCDD/Fs readily occurs during flue-gas sampling at high temperatures if the cooling within the probe is insufficient, as found for the original probe at 700 °C. It was also shown that this problem could be alleviated by using probes with an enhanced cooling capacity, such as the sub-zero probe.Although this may not affect samples collected for regulatory purposes in exit gases, it is of great importance for research conducted in the high-temperature region of the post-combustion zone. 相似文献
4.
Tiziano Gomiero Davide Pettenella Giang Phan Trieu Maurizio G. Paoletti 《Environment, Development and Sustainability》2000,2(2):119-142
Vietnam, in the ongoing transition to market economies, has to cope with high rural poverty and a dramatic process of forest loss and environment degradation, particularly in the mountainous regions. The government considers rural poverty as the main cause of environment degradation, associated with slash-and-burn cultivation and to an unclear definition of property rights on forest land. In 1993, the government launched a Forest Land Allocation programme aiming to lease forest lands to individual households and, on this basis, to solve food security problems, halt the increasing environment degradation and preserve the remaining forests.To evaluate the results of this land reform policy, two upland pilot communes have been intensively monitored. The environmental and economic impacts of the forest land reform allocation in the two study areas are presented, after providing a background on the Vietnamese situation of mountain zones. On the basis of these findings, it is discussed as to whether the current forest land allocation process may actually promote local development and natural resources conservation, and under what conditions. Deforestation problems must be tackled also with new macroeconomic policies (e.g. credit programmes to support sustainable agriculture practices) and social policy (e.g. reduction of demographic pressure), together with the reform of the State institutions (e.g. State Forest Enterprises) involved in management of the forest areas. 相似文献
5.
Boston's Chinatown is an urban community surrounded by businesses, a university, a large medical centre, and an area zoned for “adult entertainment” called the Combat Zone. The overall goal of this exploratory study was to examine the temporal and geographic distribution of street crime in Boston's Chinatown using police crime reports from the years 1988 to 2004. Crime patterns were most notably associated with the presence of the adult entertainment area, known as the Combat Zone. However, despite the decline of adult businesses over the study period, we saw small limited reduction in property and violent crimes, suggesting that the decline of these businesses did not lead to large-scale short-term (<5 years) reductions in crime. 相似文献
6.
Van Thinh Nguyen Chung Nguyen Thuy Luong Ly Thi Mai Chinh Pham Minh Anh Phan Phuong Huy Nguyen The Thuy Dang Thi Thai Phong K. 《Environmental science and pollution research international》2022,29(28):42055-42066
Environmental Science and Pollution Research - Industrial sludges from wastewater treatment plants of industrial parks and a drinking water treatment plant in northern Vietnam were investigated in... 相似文献
7.
Phan Kongkea Phan Samrach Se Soknim Sieng Huy Huoy Laingshun Kim Kyoung-Woong 《Environmental geochemistry and health》2019,41(1):401-409
Environmental Geochemistry and Health - The aim of the present study is to investigate water quality and potential trace metal contaminations in the Northeastern part of Cambodia. Tube well... 相似文献
8.
Zhuang Yahui Zhang Hongxun Wang Xiaoke & Li Changsheng Research Center for Eco-Environmental Sciences Chinese Academy of Sciences PO Box Beijing China Institute for the Study of Earth Oceans and Space University of New Hampshire Durham NH U.S.A. 《中国人口.资源与环境(英文版)》2004,(3)
The report summarizes surveys on carbon inventories and initiatives on sustainable carbon cycling taken by the Research Center for Eco-Environmental Sciences, where the authors work/worked. The first part of the report, which appeared in the preceding issue of this journal, deals with the concept of sustainable carbon cycling, the historic evolution of carbon cycling processes in China, carbon pool enhancement, value addition, carbon sequestration and carbon balance. This very paper, as the second part of the report, covers the results of carbon dynamics modeling, emission inventories of various carbon-containing greenhouse gases and their potential abatement measures. 相似文献
9.
Phan?Due?Thanh Keiji?WadaEmail author Michiko?Sato Yoshihisa?Shirayama 《Marine Biology》2005,147(5):1191-1199
Utilization of algae for decorating by the intertidal majid crab Tiarinia cornigera was examined by laboratory experiments in relation to availability of algae, presence of a predator, and the presence of
conspecific and heterospecific crabs. Different availabilities of decorating materials had a positive correlation on decorating
amount by juveniles, while the correlation was not so clear in subadults. The amount of decorating decreased with increasing
density of conspecific crabs in the presence of a predator, but there was so clear relationship in the absence of a predator.
The decrease in decorating under high density could be due to intraspecific aggression, because the superior crab, in fighting,
was found to be decorated with more algae. Tiarinia cornigera was found to be superior to the co-occurring different majid species Micippa platipes in fighting. When T. cornigera and M. platipes were housed together, the former was decorated with more algae than the latter in the presence of a predator, but in the
absence of a predator, the amount of algae was not different. Thus, presence of a predator may motivate intraspecific competition
in T. cornigera as well as interspecific competition between T. cornigera and M. platipes for decorating materials. 相似文献
10.
dos Santos IR Silva-Filho EV Schaefer C Maria Sella S Silva CA Gomes V Passos MJ Van Ngan P 《Environmental pollution (Barking, Essex : 1987)》2006,140(2):304-311
This paper provides the first quantitative information on mercury in soil, coastal sediment, and in characteristic organisms of terrestrial and shallow coastal marine ecosystems from Admiralty Bay (King George Island, Antarctica). As expected for a remote area, mercury content is low in abiotic components of the ecosystem, and probably similar to natural levels. Mercury also occurs in very low concentrations in the vegetation, invertebrates and fish. These low mercury levels may be due to sulphide formation in reducing sediments of this environment. Higher concentrations of mercury occurred in bird feathers and mammal hair, indicating biomagnification. This was not found for Zinc. These results may be useful as a reference background to detect future inputs of trace elements in this remote area of the earth. Terrestrial vegetation and bird feathers are suggested as target regional biomonitors. 相似文献