The potential of remote sensing for monitoring land cover changes and effects on physical geography in the area of Kayisdagi Mountain and its surroundings (Istanbul)

The effect of land cover change, from natural to anthropogenic, on physical geography conditions has been studied in Kayisdagi Mountain. Land degradation is the most important environmental issue involved in this study. Most forms of land degradation are natural processes accelerated by human activity. Land degradation is a human induced or natural process that negatively affects the ability of land to function effectively within an ecosystem. Environmental degradation from human pressure and land use has become a major problem in the study area because of high population growth, urbanization rate, and the associated rapid depletion of natural resources. When studying the cost of land degradation, it is not possible to ignore the role of urbanization. In particular, a major cause of deforestation is conversion to urban land. The paper reviews the principles of current remote sensing techniques considered particularly suitable for monitoring Kayisdagi Mountain and its surrounding land cover changes and their effects on physical geography conditions. In addition, this paper addresses the problem of how spatially explicit information about degradation processes in the study area rangelands can be derived from different time series of satellite data. The monitoring approach comprises the time period between 1990 and 2005. Satellite remote sensing techniques have proven to be cost effective in widespread land cover changes. Physical geography and particularly natural geomorphologic processes like erosion, mass movement, physical weathering, and chemical weathering features etc. have faced significant unnatural variation.     

Safety analysis of instantaneous release of compressed natural gas from a cylinder

This study presents a numerical model to analyze the sudden failure of compressed natural gas (CNG) cylinder onboard a CNG vehicle. The model is developed using COMSOL. It accounts for the real gas effects, physical energy, and combustion of the flammable gas. The model is tested using experimental data.The study highlight compression energy as one of the serious concern. An unintentional rupture of a compressed cylinder filled with natural gas would generate a rapid energy release in the form of the pressure energy (blast). The release of energy and gas would cause rapid mixing and generate overpressure and may also cause flash fire. A detailed failure frequency analysis is also done to analyze the effectiveness of barriers. This study identifies critical points for the safe operation of the CNG system onboard a vehicle.     

(210)Pb and composition data of near-surface sediments and interstitial waters evidencing anthropogenic inputs in Amazon River mouth, Macapá, Brazil

Activity profiles of excess ²¹⁰Pb determined in three sediment cores from Amazon River mouth, Macapá city, Brazil, provided the evaluation of sedimentation rates, contributing to a better knowledge of the hydrological conditions in the site that is the capital of Amapá State and is drained by the waters of the huge Amazon River. Chemical data were also determined in the sediments, allowing identify signatures coupled to anthropogenic inputs held in the past in Amapá State. Significant direct relationships between LOI (loss on ignition) and organic matter were found for all sediments profiles. Silica was found to be inversely related to organic matter in the three profiles; its decrease accompanied an increase on the specific surface of the sediments. This relationship was confirmed by a great number of inverse significant correlations among silica and oxides Na₂O, K₂O, CaO, MgO, Al₂O₃, P₂O₅, Fe₂O₃ and MnO. It was possible to identify the role of organic matter on adsorption of several oxides in the core sediments profiles. Apparent sediment mass accumulation rates corresponding to values between 450 and 2510 mg cm⁻² yr⁻¹ were obtained, and are compatible with the results of others studies. The ²¹⁰Pb activities in one sampling point suggested the occurrence of anthropogenic inputs related to the initial period of the mining activities conducted in Serra do Navio, Amapá State, for the commercialization of Mn ores. This was reinforced by the abrupt fluctuations in chemical data obtained for the sediments and composition of the interstitial waters occurring there. The Atlantic hurricane activity also appeared to affect the sedimentation rates in the area, as two different values were recorded in each profile.     

河流物理生境遥感监测研究与应用分析

简述了国内外河流物理生境监测研究进展和应用。从水生态监测体系完整性和物理生境监测手段的优缺点等方面,研究了河流物理生境遥感监测的必要性;结合我国水生态环境管理形势,介绍了河流物理生境遥感监测的应用领域;以辽河干流盘锦段为例,进行了物理生境遥感监测评估的实例分析。     

The business cycle and the incidence of workplace injuries: evidence from the U.S.A

Introduction

The current study explored the association between the business cycle and the incidence of workplace injuries to identify cyclically sensitive industries and the relative contribution of physical capital and labor utilization within industries.

Method

Bureau of Labor Statistics nonfatal injury rates from 1976 through 2007 were examined across five industry sectors with respect to several macroeconomic indicators. Within industries, injury associations with utilization of labor and physical capital over time were tested using time series regression methods.

Results

Pro-cyclical associations between business cycle indicators and injury incidence were observed in mining, construction, and manufacturing but not in agriculture or trade. Physical capital utilization was the highest potential contributor to injuries in mining while labor utilization was the highest potential contributor in construction. In manufacturing each effect had a similar association with injuries.

Conclusion

The incidence of workplace injury is associated with the business cycle. However, the degree of association and the mechanisms through with the business cycle affects the incidence of workplace injuries was not the same across industries.

Impact on Industry

The results suggest that firms in the construction, manufacturing, and mining industries should take additional precautionary safety measures during cyclical upturns. Potential differences among industries in the mechanisms through which the business cycle affects injury incidence suggest different protective strategies for those industries. For example, in construction, additional efforts might be undertaken to ensure workers are adequately trained and not excessively fatigued, while safety procedures continue to be followed even during boom times.     

Some Physical Properties of CdO Thin Films Used as Window Material in Photovoltaic Solar Cells

Abstract

CdO thin films which can be used in photovoltaic solar cells as window material were obtained on glass substrates at 250°C and 300°C substrate temperatures using Ultrasonic Spray Pyrolysis (USP) technique. The electrical, optical, structural, and surface properties of the films were investigated for two different substrate temperatures. After all investigations, it is concluded that, the CdO thin films can be used in photovoltaic solar cells as window materials and cell efficiencies can be increased using different growth parameters.     

上海市污水治理二期工程上升管间距模型试验研究

以上海市污水治理二期工程物理模型试验数据为基础，通过量纲分析的方法得出了污水排放口上升布置多个喷口时污水场宽度与各影响因素之间的关系式，根据污水场宽度可以确定出上升管理论间距，为实际工程中扩散器长度的确定提供理论依据。     

电厂二氧化碳捕集分离技术研究综述

电厂二氧化碳捕集与封存是二氧化碳减排措施研究热点,也是全球二氧化碳减排的重要任务之一,可分为物理吸附/吸收、化学吸收、物理-化学吸收、膜技术及生物技术等。其中物理吸附/吸收、化学吸收为电厂二氧化碳捕集主流技术。开发具有高选择性、高效率吸收剂及捕集技术,提高能源利用效率,合理布置尾部烟气脱碳处理设施是电厂二氧化碳捕集技术面临的挑战。     

浅谈体育教学中的示范艺术

本文对教师在体育教学中如何进行技术动作示范,怎样取得最佳的示范效果进行了论述,并指出它对教学质量的提高有十分重要的作用。     

Nano-sized alumina supported palladium catalysts for methane combustion with excellent thermal stability

Pd/Al₂O₃ catalysts supported on Al₂O₃ of different particle sizes were synthesized and applied in methane combustion. These catalysts were systematically characterized by Brunauer-Emmett-Teller (BET), X-ray diffraction (XRD), high resolution-transmission electron microscopy (HR-TEM), high-angle annular dark field-scanning transmission electron microscopy (HAADF-STEM), H₂-temperature-programmed reduction (H₂-TPR), O₂-temperature-programmed oxidation (O₂-TPO), X-ray photoelectron spectroscopy (XPS), and X-ray absorption fine structure (XAFS). The characterization results indicated that nano-sized Al₂O₃ enabled the uniform dispersion of palladium nanoparticles, thus contributing to the excellent catalytic performance of these nano-sized Pd/Al₂O₃ catalysts. Among them, Pd/Al₂O₃-nano-10 (Pd/Al₂O₃ supported by alumina with an average particle size of 10 nm) showed superior catalytic activity and stability for methane oxidation under harsh practical conditions. It maintained excellent catalytic performance for methane oxidation for 50 hr and remained stable even after harsh hydrothermal aging in 10 vol.% steam at 800°C for 16 hr. Characterization results revealed that the strong metal-support interactions and physical barriers provided by Al₂O₃-nano-10 suppressed the coalescence ripening of palladium species, and thus contributed to the superior sintering resistance of the Pd/Al₂O₃-nano-10 catalyst.