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71.
Agriculture consumes more than two-thirds of global fresh water out of which 90 % is used by developing countries. Freshwater consumption worldwide is expected to rise another 25 %by 2030 due to increase in population from 6.6 billion currently to about 8 billion by 2030 and over 9 billion by 2050. Worldwide climate change and variability are affecting water resources and agricultural production and in India Ganga Plain region is one of them. Hydroclimatic changes are very prominent in all the regions of Ganga Plain. Climate change and variability impacts are further drying the semi-arid areas and may cause serious problem of water and food scarcity for about 250 million people of the area. About 80 million ha out of total 141 million ha net cultivated area of India is rainfed, which contributes approximately 44 % of total food production has been severely affected by climate change. Further changing climatic conditions are causing prominent hydrological variations like change in drainage density, river morphology (tectonic control) & geometry, water quality and precipitation. Majority of the river channels seen today in the Ganga Plain has migrated from their historic positions. Large scale changes in land use and land cover pattern, cropping pattern, drainage pattern and over exploitation of water resources are modifying the hydrological cycle in Ganga basin. The frequency of floods and drought and its intensity has increased manifold. Ganga Plain rivers has changed their course with time and the regional hydrological conditions shows full control over the rates and processes by which environments geomorphically evolve. Approximately 47 % of total irrigated area of the country is located in Ganga Plain, which is severely affected by changing climatic conditions. In long run climate change will affect the quantity and quality of the crops and the crop yield is going to be down. This will increase the already high food inflation in the country. The warmer atmospheric temperatures and drought conditions will increase soil salinization, desertification and drying-up of aquifer, while flooding conditions will escalate soil erosion, soil degradation and sedimentation. The aim of this study is to understand the impact of different hydrological changes due to climatic conditions and come up with easily and economically feasible solutions effective in addressing the problem of water and food scarcity in future.  相似文献   
72.
The biggest challenge of the 21st century is to satisfy the escalating demand of energy and minimize the globally changing climate impact. Earth to air heat exchanger (EAHE) system can effectively reduce heating affects on buildings. An experimental study was carried out by designing EAHE system using low cost building materials like Bamboo (Bambuseae) and hydraform (cement and soil plaster) to reduce the energy consumption of buildings and minimize the impact of climate change. This system utilizes earth’s constant subterranean temperature for naturally heating or cooling the inlet air. This study was carried out in the North Eastern part of India. An open loop EAHE system was developed to predict the heating and cooling potential of the system. Within the system locally available bamboos were used for constructing the tunnel pipes and soil-cement mixture plaster was used to enhance the conductivity of the bamboo pipes. Soil-cement mixtures are capable of decreasing the humidity by 30 to 40 %. Majority of the North Eastern region of India, have humid climatic conditions through out the year. Experiment was performed continuously for 7 days and the result shows that irrespective to the inlet air temperature (ranges from 35 °C to 42 °C), outlet air temperature was recorded between 25 °C and 26 °C, which shows the effectiveness of the system. After a series of experimental analysis the study reveals that underground tunnel based fresh air delivery system is one of the easily feasible and economically feasible techniques which can drastically reduce the energy consumption of the buildings and help in addressing the continuously escalating demand of power and minimizing the impact of changing climatic conditions on buildings.  相似文献   
73.
Abstract

The effect of intratracheal administration of DDT (5 mg/100 g body weight) or endosulfan (1 mg/100 g body weight) to rats for three consecutive days, has been studied on liver lipid metabolism. The administration of DDT but not endosulfan significantly increased the liver weight and the microsomal protein contents. Both DDT and endosulfan treatments significantly increased the contents of microsomal phosphatidylcholine (PC), total‐free‐ and esterified cholesterol. The distribution of unsaturated fatty acids of microsomal PC and PE was increased by DDT treatment. The intratracheal administration of DDT caused fatty infiltration of liver which was probably due to increased synthesis of triglycerides (TG). This is supported by the increased incorporation of radioactive palmitate‐l‐14C into microsomal TG. However, the increased incorporation of palmitate‐l‐14C into microsomal PC and phosphatidylethanolamine (PE) after the DDT treatment, was due to the increased transacylation reaction supported by the decreased activity of microsomal phospholipase A. The intratracheal adminstration of endosulfan did not has pronounced effect on liver fatty infiltration, or transacylation reaction in microsomal PC and PE. However, the results have shown that the treatments of DDT or endosulfan increased the PC contents and the incorporation of radioactive [methyl‐3H]choline into PC of microsomes, resulting the increased synthesis of PC via CDPcholine pathway. Thus, the intratracheally administered DDT or endosulfan to rats showed that both the insecticides cause manifestations in the biochemistry of microsomal membrane lipids, although the effects of DDT being more pronounced. Therefore, the translocation effects of these insecticides or metabolites from lung to liver is established.  相似文献   
74.
Abstract

Administration of endosulfan significantly increased microsomal protein, cytochrome P‐450 content and the activity of aminopyrine N‐demethylase. Effect of endosulfan and actinomycin D either alone or together on microsomal protein, cytochrome P‐450, NADPH cytochrome c reductase, aniline hydroxylase, aminopyrine N‐demethylase, phosphatidylcholine content, incorporation of 3H‐choline and 14C‐methionine were studied in rats given amino acid deficient and supplemented diets. Administration of endosulfan significantly increased the above parameters in both the dietary groups, whereas administration of actinomycin D did not have any effect in rats fed supplemented diets, however, significant decrease in the PC and the incorporation of choline and methionine into PC of rats fed deficient diet were observed. A positive correlation in the effect of endosulfan on hepatic mixed function oxidase activity and hepatic phosphatidylcholine is observed.  相似文献   
75.
Pesticide-humic interactions are known to have environmental significance in modifying the toxicity and mobility of agricultural chemicals. to test this, interaction between gamma-hexachlorocyclohexane (gamma-HCH) released from the sand coated with gamma-HCH and humic acid was investigated using thin layer chromatography and spectral studies such as UV (ultraviolet), IR (infrared), mass and FAB (fast atom bombardment) mass spectrometry. These studies revealed the evidence of loose interchelation between gamma-HCH and humic acid. the significance of the results in relation to detoxification of gamma-HCH in aquatic ecosystems are discussed.  相似文献   
76.
Injection molded nanocomposites have been successfully fabricated from cellulose acetate (CA), eco-friendly triethyl citrate (TEC) plasticizer, and organically modified clay with and without maleic anhydride grafted cellulose acetate butyrate (CAB-g-MA) as a compatibilizer. The effects of processing conditions such as mixing methods, pre-plasticizing times, extruder retention times (RT) and addition of compatibilizer on the performance of these nanocomposites have been evaluated. The cellulosic plastic with CA/TEC (80/20 wt%) was used as the polymer matrix for nanocomposite fabrication. The morphologies of these nanocomposites were evaluated through X-ray diffraction (XRD) and transmission electron microscopy (TEM) studies. The mechanical properties of the nanocomposites were measured and have been correlated with the XRD and TEM observations. From all of the sequential mixing methods used, powder–powder mixing leads to the most transparent nanocomposites. Cellulosic plastic-based nanocomposites obtained using increased pre-plasticizing times and RT showed better exfoliated structures. In the system containing compatibilizer, the minimum retention time required for obtaining almost completely exfoliated hybrid nanocomposites was shorter than in the system without compatibilizer.  相似文献   
77.
Sustainability, industrial ecology, eco-efficiency, and green chemistry are guiding the development of the next generation of materials, products, and processes. Biodegradable plastics and bio-based polymer products based on annually renewable agricultural and biomass feedstock can form the basis for a portfolio of sustainable, eco-efficient products that can compete and capture markets currently dominated by products based exclusively on petroleum feedstock. Natural/Biofiber composites (Bio-Composites) are emerging as a viable alternative to glass fiber reinforced composites especially in automotive and building product applications. The combination of biofibers such as kenaf, hemp, flax, jute, henequen, pineapple leaf fiber, and sisal with polymer matrices from both nonrenewable and renewable resources to produce composite materials that are competitive with synthetic composites requires special attention, i.e., biofiber–matrix interface and novel processing. Natural fiber–reinforced polypropylene composites have attained commercial attraction in automotive industries. Natural fiber—polypropylene or natural fiber—polyester composites are not sufficiently eco-friendly because of the petroleum-based source and the nonbiodegradable nature of the polymer matrix. Using natural fibers with polymers based on renewable resources will allow many environmental issues to be solved. By embedding biofibers with renewable resource–based biopolymers such as cellulosic plastics; polylactides; starch plastics; polyhydroxyalkanoates (bacterial polyesters); and soy-based plastics, the so-called green bio-composites are continuously being developed.  相似文献   
78.
The paper deals with 45 species of 21 genera of fresh water blue green algae (BGA) from three different agro-climatic zones of Uttar Pradesh. Samples were collected from different habitats varying in physico-chemical properties. Out of 45 species, 13 species belonged to order Chroococcales, 31 to order Nostocales, while only 1 species belonged to order Stigonimatales i.e. Fischerella mucicola. The physico-chemical parameters like pH, temperature, dissolved oxygen, electrical conductivity, nitrate, nitrite and rainfall play an important role in the periodicity of BGA. A positive correlation was found between dissolved oxygen (DO) of different ponds and species diversity, except in the case of western region of Uttar Pradesh (Farukhabad and Mahoba districts) where a positive correlation was found in electrical conductivity and total dissolved solids.  相似文献   
79.
增加粮食需求,减少对无机氮的依赖性   总被引:1,自引:0,他引:1  
较高的作物产量通常需要较高的养分使用率,因此就使无机氮的使用增加.到2030年,估计粮食的年需求量约为28亿t,相应的无机氮消耗量为9600万t(在1995~1997年间,无机氮的年消耗量为7800万t).从全球范围来讲,由于使用无机肥料而流失到周围环境中去的无机氮目前为每年3600万t,价值117亿美元,它们对环境保护起反作用.但是,新型的提高肥料使用效率(FUE)技术可以增加产量但不使无机氯的使用成比例增加.并且,含氮养分的供应可以通过改进农业生产系统和开发如生物固氮(BNF)等可替代资源而扩大.到2030年,随着出台适当的政策、实施技术转让、对研究和投资提供支持以及在农田采用化肥使用效率(FUE)和生物固氮(BNF)技术等,可以使无机氯每年节省1000万t,价值33亿美元.  相似文献   
80.
This paper describes the development and testing of the Acid Deposition and Oxidant Model (ADOM), a nine-year project funded by a consortium consisting of Environment Ontario, Environment Canada, the German Umweltbundesamt, and the Electric Power Research Institute. The project consisted of three major phases: a design phase, an implementation phase, and an evaluation phase. In the design phase, the system being modeled was divided into its components-transport, gas phase chemistry, aqueous phase chemistry, dry deposition and cloud processes. The formulation of the modules for each of these processes was guided by the requirement that the modules reflect the state of the art, and at the same time be consistent with the available numerical resources. In the implementation phase, submodels were constructed, and then subjected to several tests, which included mathematical consistency checks, sensitivity studies, and evaluation against field and laboratory data. The modules were then assembled and interfaced with the input data sets. The codes for the modules as well as the overall model were vectorized to take advantage of the capabilities of supercomputers such as the CRAY. The North American and West German versions of the model are being tested against data collected in North America and in Europe. This paper describes the evaluation of ADOM with data associated with a regional ozone episode in Ontario in June 1983, and measurements made during an experiment to study the scavenging characteristics of spring storms in the central and northeastern United States in April 1981.  相似文献   
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