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271.
Garhwal Himalaya is an important source of wild fruit species. These wild fruit trees grow abundantly across an altitudinal gradient of Himalaya and the majority of them bear fruits during summer. Fruit varieties are eaten raw by the local inhabitants of the region and whilst they are a rich source of protein, carbohydrate, fat and other elements, compared to cultivated fruits, they have not yet been considered as a source of alternative food products. About 13 potentially exploitable species of wild fruits and one semi-domesticated species having high potential for exploitation were selected for study; six (Aegle marmelos, Berberis asiatica, Hippophae rhamnoides, Myrica nagi, Rubus ellipticus and Prunus armeniaca) were examined in detail for their economic potential. Among the wild fruits, Hippophae rhamnoides was found to be economically efficient, followed by Aegle marmelos, Rubus ellipticus and Myrica nagi, respectively. Prunus armeniaca, a semi-domesticated and less utilized fruit of the higher Himalaya, provides better economic returns on an annual basis. The authors have recently made an attempt to utilize these wild fruits as a source of income, particularly for poor rural inhabitants and unemployed youths of the region by making a variety of edible products such as jam, jelly, juice, squash, sauce, etc. The enterprise was demonstrated to the people to encourage them to adopt it in the form of a small village-level cottage industry. The present paper discusses the distribution, botany, phenology, yield, ethnobotany, and uses of these species, and the cost-benefit analysis of food products prepared from them.  相似文献   
272.
ABSTRACT: This paper suggests theoretical models to forecast the demand for recreational boats in a metropolitan area, and their expected usage in various regional water bodies and marinas. The models, which are similar to those used in transportation studies, are implemented using statistical regression analysis and can be easily applied to a wide range of case studies. The models have been used to forecast demand for boats by type and size in the Cleveland S.M.S.A. The proportion of boats attracted to boating facilities on Lake Erie has been calculated. This study is significant in suggesting a theoretically sound methodology to project facilities required for recreational boats.  相似文献   
273.
ABSTRACT: As of 1976 over 225,000 acres were being irrigated by center pivot units in a five-county area of the Columbia Basin in Oregon and Washington. Most of the development took place since 1970. Dynamic application of center pivot technology altered the concept of irrigability in the study area, converting lands that were often rolling, sandy, and plagued by wind erosion from low grade grazing to productive irrigated units. This development was entirely by private enterprise, with large corporate farms accounting for much of the effort. Little prior comprehensive planning or coordination took place. When the circulation of water is altered on such a massive scale, however, unplanned impacts may be far reaching. In this case they include:1) acceleration of the shift to high cost thermoelectric generation, 2) alteration of state institutions designed to allocate water, and 3) possible significant alterations of the socioeconomic fabric of small rural service centers.  相似文献   
274.
ABSTRACT: Existing leachate prediction models over- or underestimate leachate generation by up to three orders of magnitude. Practical experiments show that channeled flow in waste leads to rapid discharge of large leachate volumes and heterogeneous moisture distributions. In order to more accurately predict leachate generation, leachate models must be improved. To predict moisture movement through waste, the one-domain water balance model HELP, and two-domain PREFLO, are tested. Experimental waste and leachate flow values are compared with model predictions. When calibrated with experimental parameters, the HELP model yields reasonable predictions of cumulative leachate flow and PREFLO provides estimates of breakthrough time. In the short term, field capacity has to be reduced to 0.12 and effective storage and hydraulic conductivity of the waste must be increased to 0.2 and 2.2 cm/s respectively. In the long term, a new modeling approach must be developed to adequately describe the moisture movement mechanisms.  相似文献   
275.
ABSTRACT: The value of streamflow forecasts in reservoir operation depends on a number of factors and may vary considerably. Assessment of forecast benefits is presented here for three specific systems. Statistical streamflow models of increasing forecasting ability are coupled with a recently developed stochastic control method in extensive simulation experiments. The performance of the system is statisticafly evaluated with regard to energy generation and flood and drought prevention. The results indicate that forecast benefits are system specific and may range from quite substantial to fairly minimal.  相似文献   
276.
浅析成都市生活垃圾焚烧发电的经济可行性   总被引:2,自引:0,他引:2  
张发闯 《四川环境》2002,21(4):77-79,85
根据成都市生活垃圾性状和现有的工业基础及技术经济条件,对成都市建设生活垃圾焚烧发电厂的经济可行性进行了初步分析,指出上网电价为0.25元/千瓦时,政府对处置垃圾的补贴费为50元/吨,是经济可行的。  相似文献   
277.
突发性环境污染事故风险管理进展   总被引:1,自引:0,他引:1  
在介绍突发性环境污染事故的概念、类型与特性的基础上,综述了近年来国内外风险管理的进展。要对突发性环境污染事故进行风险管理,需要有组织的风险管理体系和风险管理计划。风险管理计划应当包括危害的风险评价、预防和应急反应三部分内容。文中详细阐述了突发性环境污染事故的预防、应急处理与对策、善后处理与影响评价的主要内容和方法。  相似文献   
278.
大气颗粒物中的有机酸广泛参与大气中的各种物理化学反应,对二次有机气溶胶和霾的形成贡献极大,因此分析颗粒物中有机酸的浓度分布特征、评估其污染来源、探究其二次生成,对深入研究有机气溶胶及其二次转化具有重要意义.在郑州市不同季节采集大气细颗粒物(PM2.5)样品,识别并定量二元酸类、脂肪酸类和树脂酸类有机酸共30种,探究其浓度分布特征、季节变化、来源贡献及二次生成.定量的二元酸类以丙二酸(di-C3)和琥珀酸(di-C4)含量最为丰富,并且表现出明显的季节变化特征:夏季 > 秋季 > 冬季 > 春季;脂肪酸类表现出明显的双峰优势,以棕榈酸和硬脂酸(C18)最为丰富,季节变化特征为冬季最高,春季最低.利用主成分分析结合多元线性回归(MLR)方法对郑州市PM2.5中的有机酸进行来源解析,结果表明,35%的有机酸来自于燃烧源和交通源,24%来自于烹饪源、23%来自于二次生成以及17%来自于天然源.利用标记物种的比值(如di-C3 /di-C4、F/M和C18:1 /C18)探究有机气溶胶二次形成及其老化过程.结果表明,夏季光化学反应剧烈,有机气溶胶老化或二次生产比例较高,冬季光化学反应较弱,有机气溶胶老化程度较低.采用相关性分析与MLR相结合的方法,量化了气相氧化和液相氧化对二元酸形成的相对贡献,气相氧化在采样过程中起主导作用,占比为58%,特别是夏季,占总二次转化的61%.  相似文献   
279.
城区叶面尘特性及其多环芳烃含量   总被引:7,自引:1,他引:7  
用多步连续洗脱方法采集了干线道路路侧和远离道路校园内冬青卫矛叶面积尘,研究了叶面尘的采集方法.测定了2类叶面尘的粒径分布、有机碳含量和多环芳烃含量.结果表明,所测样品上的叶面尘可以在超声条件下4min一步洗脱.路边样品叶面尘积累量几乎是校园样品的2倍.2样品粒径分布基本形态非常相似,包括200μm以上和以下2个组分.后者占绝对优势.但校园内样品叶面尘粒径明显小于路边样品,两者粒径中位数分别为17.2μm和23.1μm.路边样中相对较粗部分显然来自机动车行驶扰动.由于颗粒较细,采自校园叶面尘中多环芳烃含量略高于路边样品.但不同多环芳烃分布谱非常相似.  相似文献   
280.
海拉尔盆地乌9井煤含水热模拟生烃实验研究   总被引:1,自引:0,他引:1  
付丽 《地球与环境》2003,31(2):100-104
通过对海拉尔盆地乌 9井煤进行含水热模拟实验 ,结果反映出煤在早期阶段产气率较小 ,且以生成非烃气为主 ,35 0℃后产气率明显增大 ,随模拟温度的增加烃类气体的组分碳同位素序列由正碳序列变为同位素序列倒转 ,说明了温度对天然气的组分碳同位素序列有影响。热模拟煤中可溶有机质表现出低饱和烃和高非烃、沥青质的特点 ,色谱上具有较高的Pr/Ph。煤具有两次生油高峰 :即未熟 低熟油生油高峰 ,对应Ro =0 5 % ,产油率为 0 .85 % ;第二次生油高峰Ro为 0 .85 % ,产油率 0 .93%。煤显微组分组成特征决定了煤的生油特征。  相似文献   
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