Papers by Keyword: Environmental Factor

Abstract: Location of municipal solid waste landfills in Malaysia has been attributed to causing bad odour, dust, litter, unattractive neighbourhoods, groundwater contamination, hazardous waste pollution and etc. Therefore, proper selection criteria are very important in preliminary siting of new landfill to avoid undesirable long-term effects. This article presents a comprehensive review of landfill spatial siting criteria and their frequency of occurrence (ranked order) found in literatures. The highest ranked criterion is the surface water and the lowest is climate/rainfall density. The dissimilarity in the criteria is found to be specifically influenced by published guidelines or policies from respective countries. In addition, group ranking of spatial criteria from frequency study made on Malaysian local literatures shows that wind factor and infrastructure (utilities) has never been considered in landfill site selection process here. These factors cannot be ignored because enhancing the condition of social, economic and environmental efficiency is part of promoting sustainable development. Subsequently, a benchmarking process of common environmental, physical and socio-economic (EPSE) criteria made with Malaysian landfill siting guideline; National Strategic Plan for Solid Waste Management and Environmental Impact Assessment Guidelines for Municipal Solid Waste and Sewage Treatment and Disposal Project. The bench mark process is useful for research references and its uniformity provides efficient site selection process in solid waste management.

Abstract: The photovoltaic system converts electrical energy from solar radiation energy. It is preferable because it has no moving parts and low pollution to the environment. The performance of photovoltaic system has been decided with environmental aspects apart from the photovoltaic system specifications and incident solar radiation. In this research, the influence of relative humidity on photovoltaic system is considered for evaluating the performance and to draw the characteristic curves during winter (December and January) period. The photovoltaic system which installed at Chennai city, India, is exposed to high relative humidity even during winter season. The 3kW photovoltaic system behaviour is considered and measures the photovoltaic output voltage and output current with the effect of relative humidity. The performance curves shows that high relative humidity reduces the output voltage and current from photovoltaic system. It is same as the influence of other adverse environmental factors to degrade the operation and life span of photovoltaic system.

Abstract: Incremental tendency method is used to discriminate master factors of regional environmental quality. In this article, incremental tendency method has been revised. Taken Tianjinport sea area as an example, the collation of environmental quality master factors in 2012 has been listed. It is advanced that environmental quality master factors of Tianjin port sea area are mainly inorganic nitrogen and petroleum substances, and pollution management should also be aimed at these types of substances. Finally the meaning of new model in application has been explained. It provided practical basis for sustainable development of Tianjin sea area protection.

Abstract: With the expansion and modernization of cities, the intensity and density of urban underground pipelines are dramatically increasing, and the surrounding environment of the underground pipelines is more complex. This paper analyzed the environmental factors of the pipelines, and divided the environmental factors into soil environment, external force and natural disaster. By using the Accident Tree Analysis researched the basic events that cause the underground pipeline accidents, and the results shows that the most important basic events are the human constructions, without protective measures, and the second important basic events are corrosion failure, no timely detection and treatment of the environment risks, such as underground cavity, encroachment. The evolution mechanism of underground pipeline accident was analyzed. According to the analysis results, the soil surrounding the underground pipelines may be evolved into unstable-state under the influence of environmental inducements, finally the underground pipelines may be damaged and the accidents will happen without any protective measures.

Abstract: The denitrification and its influencing factors were studied in reed, suaeda heteroptera and reed degraded wetland. PDR were similar in reed and suaeda heteroptera wetland; primary influencing factors were temperature, nitrate and TOC. pN₂O, N₂O/ (N₂O + N₂) were less in reed wetland than that in suaeda heteroptera wetland; significant influencing factor was ORP. Compared with the reed wetland, the PDR in reed degraded wetland had significantly reduced, whose limiting factor was TOC concentration in soil; the ration of N₂O/ (N₂O + N₂) had increased and the pN₂O had no obvious change in reed degraded wetland.

Abstract: Aerial cameras are widely used in resource surveys, topographic mapping, military reconnaissance and many other fields. This paper introduced the sort of aerial camera, the development in our country and abroad about the theory of secondary spectrum. In order to meet the requirement for simple structure and high-resolution, the optical design of the apochromatism objective lens of aerial camera is achieved by common optical material. Objective’s focal length is 400mm, relative aperture is F/4 and work waveband is 420nm~850nm. Designing results show that the MTF of every field above 0.75 in 60lp/mm and satisfy the requirements of imaging for large frame array CCD whose effective size is 36mm×48mm.

Abstract: To solve the problems of the environmental factor detection and data management in the methane fermentation, this paper proposes a design based on ZigBee and PDA technology. Sensor node with CC2530 as the core can implement detection of oxidation-reduction potential, PH value, temperature, and liquid level. Coordinator node adopts ARM11 and is designed to be a PDA form, which is flexible and easy to use. On the basis of the analysis in ZStack protocol stack, the sensor signal acquisition program is accomplished. Customize wince6.0 embedded operating systems, and transplant an embedded SQlite database for powerful data management features. By using serial communication and multi-thread communication strategies, the Zigbee network data acquisition, acquisition cycle settings, power mode settings, and time synchronous adjustment can be accomplished. As the result of the test, the average packet loss rate of the network transmission is 0.375%. The data comparison charts of sensor nodes with standard instrument detected in continuous 24h are essentially coincident, and it indicates that the sensor circuit has been designed properly, and ZigBee network data transmission is stability, so it can meet the actual requirements of applications. Meanwhile, the system is easy to extend for different scale methane engineering application.

Abstract: In engineering practices, aircraft structures have been damaged due to the structural corrosion, the corrosive problem of aircrafts needs to call high attentions for researchers because aircraft structures are composed of metals and compound metals. In this paper, corrosion problems and structural reliability of aircraft structures are discussed. Corrosion morphology and mechanism of aircraft structures are analyzed based on metal corrosion theory. The characteristics of the various types of corrosions of aircraft structures have been enumerated. The effect of environments in corrosion process of aircraft structures is studied. The law of corrosion developed at aircraft structural parts or materials is summarized. This research contributes to improving professionals capacity of corrosion prevention and control. It also provides technical support for aircraft maintainers.

Abstract: Influential factors of sustainable development of rare earth industry mainly refer to resource utilization, social economy, environment, policies and regulations. Existing control index of mining plays a positive role in sustainable development. Meanwhile, the government departments are also relevant parts of such process. Unrestrained exploitation and production revealed short-sighted behavior in the development of rare earth industry. Consequently, the following measures should be taken for sustainable development so as to strengthen environment protection and industrial concentration by further restructuring of rare earth enterprises.

Abstract: The relationship between bacterioplankton community composition and environmental factors in a constructed small-scale reservoir was studied. Polymerase chain reaction (PCR) - denaturing gradient gel electrophoresis (DGGE) fingerprinting was used to detect plankton communities. Species composition of the sites was heterogeneous; 60 % of the total species were restricted to single samples and only 2 bands were found in all investigated samples. Clustering analysis illustrated a strong correlation between samples taken from same sites. Canonical correspondence analysis (CCA) results showed that bacterioplankton community composition was primarily correlated with NO₃^--N and COD_Cr. Bacterioplankton community composition could reflect the environmental conditions to some extent.