共查询到20条相似文献,搜索用时 0 毫秒
1.
Air pollution is caused by variety of sources such as industries, vehicles, cremation, bakeries, and open burning. These sources have variation in emission with different time scales. Industry and bakeries have variation in emission with day or week, rest of the sources like vehicles and domestic sector have variation with time in a day. In fact, vehicles have a large variation in emission with time period of the day. The average concentration of 24 h is much less than hourly concentration of peak time when there is heavy vehicular emissions. The hourly concentration of off-peak time or lean time is very low due to low emission for that period. The air quality standards of India are prescribed for 24-h average concentration with which the predicted average concentration from models is compared. However, the peak time concentration may be much higher than the standard. In the peak time, outdoor concentration is more and since a large proportion of the population is out the exposure is also very high and can cause severe health effect. In this paper, vehicular pollution modeling has been carried out using AERMOD with simulated meteorology by Weather Research and Forecasting model. NOx and PM concentrations were 3.6 and 1.45 times higher in peak time than off-peak and evening peak, respectively. Lean time has higher concentration for both NOx and PM than off-peak and evening peak. It shows the misleading concept of comparing average predicted concentration of 24 h with standards for vehicles. 相似文献
2.
将模糊控制策略应用于车用复合电源的管理中.基于超级电容和动力电池组的试验数据建立了其动态仿真模型,制定了复合电源的模糊控制策略和逻辑门限控制策略.依据选择的复合电源拓扑结构,选择城市测功机循环工况(UDDS),针对复合电源在整车上的应用进行了此两种控制策略的仿真对比分析.仿真结果表明,模糊控制策略可以更好地发挥超级电容... 相似文献
3.
The reliability analysis of new technology-based transmitters has to deal with specific issues: various interactions between both material elements and functions, undefined behaviours under faulty conditions, several transmitted data, and little reliability feedback. To handle these particularities, a “3-step” model is proposed, based on goal tree-success tree (GTST) approaches to represent both the functional and material aspects, and includes the faults and failures as a third part for supporting reliability analyses. The behavioural aspects are provided by relationship matrices, also denoted master logic diagrams (MLD), with stochastic values which represent direct relationships between system elements. Relationship analyses are then proposed to assess the effect of any fault or failure on any material element or function. Taking these relationships into account, the probabilities of malfunction and failure modes are evaluated according to time. Furthermore, uncertainty analyses tend to show that even if the input data and system behaviour are not well known, these previous results can be obtained in a relatively precise way. An illustration is provided by a case study on an infrared gas transmitter. These properties make the proposed model and corresponding reliability analyses especially suitable for intelligent transmitters (or “smart sensors”). 相似文献
6.
本文为自动洗片机用高温快速显影液的科学管理与质量保证提供了简便、科学的检测方法,力医(?)影像质量的提高提供了可靠的保证。具有科学性、实用性、普及性。 相似文献
7.
Clean Technologies and Environmental Policy - Coal is expected to remain a significant power supply source worldwide and shifting to carbon-neutral fuels will be challenging because of growing... 相似文献
8.
The kinetics of solid state reactions has been reexamined to include solutions for mixed control by an interfacial process
and diffusion. The Valensi-Carter, Ginstling-Brounshtein, and other quasi steady state models have been extended to include
mixed control. Solutions were obtained for planar, cylindrical and spherical particles. Mixed control may occur at either
the inner or outer interface for cylindrical or spherical particles, for which significantly different solutions are valid.
Mixed control at the outer interface usually gives faster reaction than mixed control at the inner interface. The kinetics
of these solid state reactions with mixed control is usually nearly independent of the product to reagent volume ratio.
This revised version was published online in November 2006 with corrections to the Cover Date. 相似文献
10.
The various toxic contaminants such as dyes, heavy metals, pesticides, rare‐earth elements, and hazardous chemicals are the major threats to all the flora and fauna. Owing to the harmful ill effects caused by the toxic contaminants, it is necessary to eliminate these compounds from the authors’ ecosystem. The chitosan magnetic nanomaterials (CMNPs) are one of the superior materials used in the wastewater treatment through various conventional technologies. The chitosan is a natural source obtained from the crustacean shells of crabs, prawns etc. The magnetic nanomaterial prepared by the reinforcement of chitosan is highly effective in the removal of heavy metals, dyes, organic matter, and harmful chemicals. It is used in various technologies such as adsorption, flocculation, immobilisation, photocatalytic technology, and bioremediation. This possesses unique surface and magnetic characteristics, Moreover, it is simple, economically feasible, and eco‐friendly material used efficiently in wastewater treatment. This review paper depicts the overview of CMNP in the industrial effluent treatment.Inspec keywords: effluents, adsorption, dyes, water pollution control, wastewater treatment, nanofabrication, nanoparticles, catalysis, industrial waste, photochemistry, flocculation, contamination, magnetic particlesOther keywords: CMNPs, water pollution control, toxic contaminants, dyes, heavy metals, pesticides, rare‐earth elements, hazardous chemicals, flora, fauna, chitosan magnetic nanomaterials, wastewater treatment, natural source, magnetic nanomaterial, organic matter, harmful chemicals, photocatalytic technology, magnetic characteristics, eco‐friendly material, industrial effluent treatment 相似文献
11.
电解锰行业废水排放量大,污染物浓度高,属于高污染行业,是我国实现污染物控制减排的主要威胁之一。通过对电解锰行业污染防治现状进行分析,构建了污染防治技术评估指标体系,利用层次分析法确定各评价指标的权重,利用综合评价值法对电解锰行业污染防治技术进行了评估。在此基础上,利用自底向上模型对评估出的最佳可行技术的污染减排潜力进行预测。结果表明,与基准年2010年相比,2015年电解锰行业废水排放总量可削减270多万吨,氨氮减排6.6×104 t,减排回收的锰和重铬酸钾可分别达到1.9×105 t和3.747×107 t,锰渣减排4×106 t;同时也表明清洁生产技术减排的能力高于末端治理技术减排,清洁生产技术具有较大的推广普及潜力。 相似文献
13.
室内空气污染治理产品分为试剂类产品和空气净化器两类,对这两类产品的治理对象、治理效果进行了对比研究,研究结果表明,两类产品分别适用于污染严重和污染较轻的室内环境,试剂类产品更符合中国国情,具有多种技术优势的多功能空气净化器应是净化器发展的方向,综合使用两类治理产品更有利于提高室内空气品质. 相似文献
14.
A narrow band antenna of dimensions 0.54λ x 0.28λ x 0.09λ is presented. The design is suited for use in cellular Radio-over-Fibre networks. Associated mobile equipment using the international unlicensed WiMAX band (5.470-5.725 GHz) is also described. The antenna is well matched across the band and is suitable for a full-duplex bi-directional system with simultaneous transmission (T x) and reception (R x). It can be used with mobile handsets offering WiMAX connections, and in multi-sector configurations for vehicular communication systems. 相似文献
15.
Challenges in measurement are related to the changes taking place in emerging technologies, quality assessment, and production. Strategies in product genesis and quality are discussed together with the impact of emerging technologies. The differences between traditional and modern approaches in measurement and instrumentation are compared 相似文献
16.
A review of the published works on the use of different methods of analysis for studying anthropogenic pollution of environmental objects with platinum group metals (PGMs) for 2011–2013 is presented. The results of the recent studies on the content of PGMs in environmental objects of big cities are provided. 相似文献
18.
This paper presents a 24-GHz transmitter for ultra-wideband short-range radar applications fabricated in a 0.13-μm SiGe:C BiCMOS technology. The circuit is composed of a frequency synthesiser, based on 24-GHz voltage-controlled oscillator in an N-integer phase-locked loop (PLL), a RF switch delivering a 0-dBm output power, and a tunable rectangular pulse generator, whose pulse width covers a range between 0.5 and 1.2 ns. The transmitter has been developed for a flip-chip bumping assembly on a module with an UWB antenna. Assuming a 10.5-dBi antenna gain, it is compliant with European Telecommunications Standards Institute (ETSI) transmission mask and is able to cover the main automotive applications addressing both a resolution better than 0.1 m and maximum unambiguous range of 15 m. 相似文献
19.
The a posteriori error estimation in constitutive law has already been extensively developed and applied to finite element solutions of structural analysis problems. The paper presents an extension of this estimator to problems governed by the Helmholtz equation (e.g. acoustic problems) that we have already partially reported, this paper containing informations about the construction of the admissible fields for acoustics. Moreover, it has been proven that the upper bound property of this estimator applied to elasticity problems (the error in constitutive law bounds from above the exact error in energy norm) does not generally apply to acoustic formulations due to the presence of the specific pollution error. The numerical investigations of the present paper confirm that the upper bound property of this type of estimator is verified only in the case of low (non‐dimensional) wave numbers while it is violated for high wave numbers due to the pollution effect. Copyright © 1999 John Wiley & Sons, Ltd. 相似文献
20.
In recent years, there have been a number of toxic accidents on the sea and on land which have caused pollution down current, down wind and down stream. Four were dramatic and these four have led to substantial changes in the way we deal with risk to the environment. There have also been increasing concerns about a less spectacular but equally concerning problem, acid rain, though attempts to deal with this problem have been less successful. Perhaps the drama was lacking. In all these cases, unfortunately, the less developed countries can ill afford the costs of prevention and this means they are often the home of environmentally unfriendly development. While the current approaches to such problems will continue, it is likely that the countries on the receiving end of such pollution, especially if they have economic and military power, will seek more forceful solutions. One outcome may be a UN-sponsored environmental police force. 相似文献
|