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41.
42.
Within the electronics industry, counterfeit electronic components entering the supply chain have steadily become an increasing threat accounting for more than 8 % of global merchandise trade and an annual $600 billion enterprise. Currently, there are not many cost-effective and nonintrusive solutions for counterfeit detection of electronic parts. In this paper, the authors present a statistical approach for detecting counterfeit components based on infrared (IR) analysis by the use of independent component analysis (ICA). As a prominent higher-order statistical analysis technique, ICA is capable of extracting relevant features from IR data. The latest applications and the extended algorithms of ICA have been elucidated for the purposes of classification and identification of counterfeit electronic parts. The theoretical framework of ICA is presented along with extensive experimental results to illustrate its feature extraction function in counterfeit electronic parts detection.  相似文献   
43.

Demand for particleboards keeps increasing and as such more trees are fell for its production, engendering deforestation. For the purpose of reducing falling of trees, this study, focused on recycling of waste paper in the development of paperboard as alternative to particleboards used for furniture and interior household applications. Kenaf fiber (KF) was blended at varying proportions of 0, 1, 2, 3, 4, and 5 wt.% with 20 wt.% constant cement and 20 wt.% constant coconut shell powder while the remaining was paper pulp. Board specimen developed were cured for 14, 28, and 90 days and mechanical properties were examined. Results obtained showed that fiber dosage improved bond strength and screw holding strengths as compared with the control mix. Similarly, modulus of rupture was enhanced with KF loading as compared with control mix while 1 to 3 wt.% KF spawned enhancement of modulus of elasticity. However, 4 and 5 wt.% KF led to a reduction in the modulus. Infusion of the fiber enhanced tensile strength from 1 to 3 wt.% content. 14-day and 28-day curing periods were observed to improve properties while the 90-day curing period is detrimental to all properties. Optimization via signal-to-noise ratio revealed an optimum mix of 2 wt.% obtained for fiber and an optimum curing duration of 28 days.

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44.
Use of irrigation water available from various sources in agriculture is justified on agronomic and economic grounds but care must be taken to minimize its adverse environmental and health impacts. During the study 44 water samples, available from the various resources viz., canal, sewage pipe line, tube wells in confined aquifers, tube wells in unconfined aquifers, and wells in the Chaka block district Allahabad, were chemically analyzed to check its suitability for irrigation and to classify it according to amount of salts present. The analysis reveals that most of the samples were within the lower alkalinity limit (pH 7.17–8.42), except sewage water (pH 7.34–9.04). The electrical conductivity of the samples ranged from 0.26 to 1.37 millimhos/cm. Potassium, sodium, calcium, and phosphorus are all found to be in permissible range except one sample in the village Kuria in which Na percentage was found in doubtful category. The other parameters like sodium adsorption ratio, SAR (1.17–2.74), residual sodium carbonate, RSC (?4.46 to ?1.07), and soluble sodium percentage, SSP (63.97–28.15) were also found below the permissible limit.  相似文献   
45.
Carbon dioxide (CO2) emissions from inland waters to the atmosphere are a pivotal component of the global carbon budget. Anthropogenic land use can influence riverine CO2 emissions, but empirical data exploring cause-effect relationships remain limited. Here, we investigated CO2 partial pressures (pCO2) and degassing in a monsoonal river (Yue River) within the Han River draining to the Yangtze in China. Almost 90% of river samples were supersaturated in CO2 with a mean ± standard deviation of 1474 ± 1614 µatm, leading to emissions of 557 - 971 mmol/m2/day from river water to the atmosphere. Annual CO2 emissions were 1.6 - 2.8 times greater than the longitudinal exports of riverine dissolved inorganic and organic carbon. pCO2 was positively correlated to anthropogenic land use (urban and farmland), and negatively correlated to forest cover. pCO2 also had significant and positive relationships with total dissolved nitrogen and total dissolved phosphorus. Stepwise multiple regression models were developed to predict pCO2. Farmland and urban land released nutrients and organic matter to the river system, driving riverine pCO2 enrichment due to enhanced respiration in these heterotrophic rivers. Overall, we show the crucial role of land use driving riverine pCO2, which should be considered in future large-scale estimates of CO2 emissions from streams. Land use change can thus modify the carbon balance of urban-river systems by enhancing river emissions, and reforestation helps carbon neutral in rivers.  相似文献   
46.
Environmental Science and Pollution Research - Toxicological studies use “specialty chemicals” and, thus, should assess and report both identity and degree of purity (homogeneity) of...  相似文献   
47.
Powdered maize tassels were studied and found to exhibit metal sorption properties due to the availability of functional groups. The tassels have a high amount of soluble organic substances that can dissolve in aqueous media, contributing to secondary pollution during a water treatment process. A chelating agent was chemically attached on the maize tassels with a view to increase the sorption capacity, minimize leaching, and enhance the tassels’ stability. Thermogravimetric analysis confirmed that modification improved their thermal stability to withstand temperatures above 600°C as well as reduced the “secondary pollution”. The modified sorbent was employed for the sorption of lead, copper, and cadmium ions in both the model solutions and the real samples. The contact time and pH were optimized after which Langmuir and Freundlich isotherms were applied to the data. The sorption capacities for Cu2+, Cd2+, and Pb2+ improved from 3.4, 0.8, and 1.7?g?kg?1, respectively, to 6.3, 2.6, and 2.6?g?kg?1 in the same order. The sorbent was shown to remove up to 95% of the metals in less than 10 min. This study has a potential application for the remediation of polluted waters.  相似文献   
48.
The construction sector carries out a very important role in the development of society. It is a basic component of economic activity, having a great influence on employment generation and country growth. The sector generates appreciable environmental changes and effects throughout the planet, leading to gradual exhaustion of natural resources and contamination of basic elements, such as air, water and soil. Recently, there have been advances in favour of more environmentally friendly buildings. Basically, sustainable construction has centred on residential and office buildings. It could be said that there is a lack of sustainability in the construction of industrial buildings, as they present characteristics which differ from other building typologies. This article aims to assess and analyze industrial building environmental effects, and considers a set of green study criteria, such as: location, materials, energy and water consumption, construction and deconstruction characteristics, and waste management in industrial building. At the same time, the studies are hierarchically structured into different assessment elements, such as: criteria, subcriteria and, finally, indicators, comprising the assessment model.  相似文献   
49.
ABSTRACT: Water quality was monitored for 17 months during base flow periods in six agricultural watersheds to evaluate the impact of riparian vegetation on suspended solids and nutrient concentrations. In areas without riparian vegetation, both instream algal production and seasonal low flows appeared to be major determinants of suspended solids, turbidity, and phosphorus concentrations. Peak levels of all parameters were reached during the summer when flows were reduced and benthic algal production was high. Similar summer peaks were reached in streams receiving major point inputs but peaks occurred downstream from the input. Instream organic production was less important in regulating water quality in areas with riparian vegetation and permanent flows. Concentrations of suspended solids remained relatively constant, while phosphorus and turbidity increased in association with leaf fall in autumn. Intermittent flow conditions in summer increased the importance of instream organic production in controlling water quality, even when riparian vegetation was present. Efforts to improve water quality in agricultural watersheds during base flow should emphasize maintenance of riparian vegetation and stable flow conditions.  相似文献   
50.
ABSTRACT: The accurate and reliable determination of floodplains, floodway boundaries, and flood water elevations are integral requirements of Flood Insurance Studies. These studies are intended to be used for determining the flood insurance rates. Therefore, the accuracy of the water surface profiles are important. To ensure the high degree of accuracy, the HUD Flood Insurance Administration has developed standards which must be met in the analysis of water surface profiles. A somewhat less accurate study is required for the preparation of Flood Emergency Plans. As part of the flood insurance studies of eight locations in the State of North Dakota, various flood hazard and floodplain information reports were reviewed. The hydrologic and hydraulic analyses, especially the computation of the 100-year water surface profiles, were completed using both simplified and complex hydraulic computation methods. Significant differences were found (1 to 3 feet) between the profiles computed by the SCS simplified method and those computed by HEC-2 computer program. However, the floodplain boundaries determined by both methods were found to be similar. Approximate methods are recommended for rapid determination of the floodplain, floodway boundaries, and inundation area mapping, while sophisticated computer programs (HEC-2) are recommended to be used for developing areas where the 100-year flood elevation has a significant impact on the cost of land development.  相似文献   
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