Multi-scale spatial determinants of dissolved oxygen and nutrients in Qiantang River, China

This study employed spatial regression to analyze the determinants of dissolved oxygen (DO) and nutrients in the Qiantang River, China. Determinants of their spatial patterns in 1996 and 2003 as well as their dynamics during this time period were characterized at sub-basin and 500-m riparian buffer scales. Results indicated that the determinants differed by variable and by scale. Built-ups, farmland, water body, population density and gross domestic product were positive indicators for nutrient pollution and hypoxia, while distance to river source and forest were negative indicators. Higher slope variability indicates more DO and nutrients. In addition, built-up increases that were accelerated by population growth and economic development accounted for DO and nutrients dynamics to a large extent. This study highlighted that incorporation of spatial autocorrelation into regression was not only a methodological advantage but also a promising management tool.     

Applications of steroid drugs entrapped in cyclodextrins

Environmental Chemistry Letters - Steroids are abundant in living organisms and are responsible for various biological functions. They are good candidates for inclusion complexes formation with...     

The degradation of cyanide by anodic electrooxidation using different anode materials

Cyanides are very popular electrolytes used in metal electroplating, metal ore processing, chemical and electrochemical applications. Due to wide utility of these technologies cyanides become increasingly harmful effluent, which has to be treated. One of the best ways to degrade cyanides is an anodic electrooxidation. In this work the destruction of free cyanide on platinum, titanium and stainless steel (SS) electrodes has been investigated. It was determined that anode material greatly influences the process of cyanide electrooxidation. The best results were obtained by using the Pt electrode. This kind of anode allows us to reduce CN^? concentration from 0.1 M to 0.06 M during the first hour of electrolysis at a current density of 200 A m^?2, with a current efficiency up to 80%. To substitute expensive Pt anodes Ti electrodes covered with nanolayers of Pt were prepared and used for the anodic oxidation of cyanide ions. An effect of a thickness of Pt layer and temperature of an electrolyte solution were studied. It was established that using platinized Ti electrodes the current efficiencies of electrooxidation of cyanides of about 60% can be obtained. The usage of chloride ions to facilitate the destruction of cyanide was also studied.     

Integrating empirical and heuristic knowledge in a KBS to approach stream eutrophication

The nutrient enrichment of rivers and its consequences are among the most severe water quality problems in Europe, causing eutrophication and other problems. The decision-making processes involved in the management of these problems require extensive human expertise from people who deal directly with day-to-day stream problems, as well as empirical knowledge based on scientific research. This means that eutrophication is a complex problem, the optimal management of which requires an integrated and multidisciplinary approach. This approach can be taken using a Knowledge-Based System (KBS) built upon the concepts and methods of human reasoning. Accordingly, a KBS was developed within the STREAMES project. In this KBS most of the knowledge needed for managing eutrophication problems was organised and structured in the form of a decision tree (DT). The methodology specially developed to build this KBS, as well as the internal structure of the eutrophication decision tree, is presented here. The good DT obtained led to consider the KBS a suitable tool to support the management of eutrophication.     

基于电磁感应和位移传感原理的电梯门锁啮合长度检测研究

电梯门锁锁紧元件啮合状态可靠性是确保电梯门系统安全运行的重要保障。针对现有电梯门锁啮合长度检验方法存在的测量精度不足、自动化程度低、通用性不强等问题,提出了一种基于传感器的检测方法。分析了电磁感应开关通断检测原理和接触式位移传感工作原理,在此基础上开发了门锁啮合长度检測装置,并介绍了使用该装置的检验步骤。实测结果表明:该检验方法和检验装置可以实现门锁啮合长度的快速准确检验,数据可重复性高。     

Managing occupational injuries records in Slovenia from 1948 to 2008

The aim of this study is to examine and compare all publicly accessible data on occupational injuries in Slovenia in the period from 1948 to 2008, obtained either from archives or websites. The data obtained from five different sources which have been formally collecting and presenting data on occupational injuries in Slovenia (Labour Inspectorate of the Republic of Slovenia – LIRS, Institute of Public Health of the Republic of Slovenia – IPHRS, International Labour Organization – ILO, Statistical Office of the Republic of Slovenia – SORS, and issues of the Journal of Occupational Safety and Fire Safety) were reviewed and managed. Since the early 1960s, there has been a significant decrease of fatal and non-fatal occupational injuries in Slovenia. Problems related to gathering and interpreting data on occupational injuries are also discussed with special emphasize on diversity of models used for occupational injuries data collecting. The results of the 60-year-long retrospective study can also be of assistance for professionals involved in planning, implementing and controlling the national policy and/or regional policies on safety and health at work.     

Benzene, toluene, ethyl benzene and xylenes in ambient air and Pinus sylvestris L. needles: a comparative study between Belgium, Hungary and Latvia

Concentrations of benzene, toluene, ethyl benzene and xylenes (BTEX) in ambient air and in 1 yr old Pinus sylvestris pine needles were monitored along a busy road, petrol station and rural area of Belgium, Hungary and Latvia in a 1 yr period. To test P. sylvestris as a possible biomonitor for the BTEX concentrations, samples were taken in the four seasons. As the distribution of data was not normal, the level of pollution on different sites and seasons was compared and evaluated by non-parametric tests. The measured air concentrations did not differ significantly from one season to another throughout the year. There were, however, differences between sampling places. The C₂-alkylbenzene and toluene concentrations in the needles were similar in the autumn/winter and spring/summer periods but a significant decrease in their concentration was observed in every place between winter and spring. This effect was less obvious for toluene.     

Canopy leaching of nutrients and metals in a mountain spruce forest

Precipitation and throughfall fluxes of major ions, nutrients (C, N, P), and metals (Al, Fe, Mn), and the chemical composition of litter fall and living plant tissue in Norway spruce stands (the Bohemian Forest; Czech Republic), were used to evaluate how microbial processes and decay of plant tissue in canopies influence canopy leaching (CL) of elements. Proton exchange for Mg²⁺, Ca²⁺, and K⁺ in decaying biomass and co-transport of Ca²⁺ and K⁺ out of plant cells with organic acid anions were the most likely processes contributing to CL of base cations. The CL of total P and N (and also NO₃^?) was minor. Important proportions of the N and P mineral forms were transformed to organic forms by microbial processes (primary and bacterial production), with the respective CL of ?13.9 and 16.4 mmol m^?2 yr^?1 for NH₄⁺ and organic N, and ?0.33 and 0.22 mmol m^?2 yr^?1 for dissolved reactive P (DRP) and organic P. Most of particulate P and N in throughfall (～90%) originated from microbial DRP and NH₄⁺ transformations, but particulate C mostly came from the fragmentation of plant tissue (58%). Among metals, CL was not observed for Al, was small for Fe (0.3 mmol m^?2 yr^?1), and greatest for Mn (0.9 mmol m^?2 yr^?1) due to leaching from decaying tissue by acidic precipitation.