Evaluation of the pollution of the surface waters of Greece from the priority compounds of list II, 76/464/EEC directive, and other toxic compounds

The pollution of the surface waters of Greece from the priority compounds of 76/464/EEC Directive was evaluated. The occurrence of 92 toxic compounds, 64 of which belong to priority compounds of List II, candidates for List I, of 76/464/EEC Directive, was studied in surface waters and wastewater through the developed network of 62 sampling stations, which covers the whole Greek territory. The analytical determination was performed by Purge and Trap-Gas chromatography-Mass spectrometry for volatile and semivolatile organic compounds (VOCs), Gas Chromatography-Electron Capture Detection for organochlorine insecticides, Gas Chromatography-Nitrogen Phosphorous Detection for organophosphorous insecticides, High Performance Liquid Chromatography-Photodiode Array Detection for herbicides, and Electrothermal Atomic Absorption Spectrophotometry and Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES) for metals and the toluene extractable organotin compounds. The concentrations of VOCs and insecticides detected in the surface waters of Greece were very low, whereas the concentrations of herbicides and metals ranged generally at moderate levels. VOCs were detected almost exclusively in the rivers and very rarely in the lakes, while the frequency of occurrence of insecticides, herbicides and metals was similar for rivers and lakes. Water quality objectives (WQO) and emission limit values (ELV) have been laid down in national legal framework for a number of compounds detected in the samples, in order to safeguard the quality of surface waters from any future deterioration.     

Response of Drinking-water Reservoir Ecosystems to Decreased Acidic Atmospheric Deposition in SE Germany: Signs of Biological Recovery

Strongly decreasing atmospheric emissions and acidic deposition during the 1990s have initiated chemical reversal from acidification in several drinking-water reservoirs of the Erzgebirge, SE Germany. We studied responses of phytoplankton, zooplankton and fish stocks in five reservoirs and at enclosure scale after experimental neutralization of 1,200 m³ of lake water. About 4 months after this treatment, diatoms and cryptomonads replaced the predominating chrysophytes and dinoflagellates. The colonization by acid-sensitive species of green algae, cryptomonads, rotifers and Cladocera (e.g. Bosmina longirostris) is explained by the occurrence of dormant stages or by survival of individuals in very low abundances. Analogous to the enclosure experiment, three reservoirs showed significantly (p < 0.01) falling trends of chlorophyll a and phytoplankton biovolume, mainly due to the decline of dinoflagellates. Picoplankton and diatoms increased slightly in two reservoirs. The zooplankton communities were dominated by rotifers and small Cladocera. Representatives of the genus Daphnia were lacking. Two reservoirs were re-colonized by zooplanktivorous fish populations of either perch (Perca fluviatilis) or sunbleak (Leucaspius delineatus). The latter exhibited extremely high fluctuating abundance and biomass and even suffered from a population crash. This natural mortality was caused by a limited food supply. Hence, severe top-down control may delay the recovery of larger zooplankton species like daphnids. Fishery management comprising the introduction of predatory fishes can help to control zooplanktivorous fish populations and to prevent their mass mortality.     

Managing the career deal: the psychological contract as a framework for understanding career management,organizational commitment and work behavior

This paper reports the findings of a study that investigated the relationship between different kinds of career management activities, the psychological contract, and outcomes of psychological contract fulfillment. The study tested a series of linked hypotheses which propose that individual career management behavior is associated with the experience of organizational career management help, which is related to fulfillment of the psychological contract. Fulfillment of the psychological contract in turn is linked to organizational commitment and is associated with behaviors at work, including absenteeism, turnover, and independent ratings of job performance. The findings provide some support for these proposed links. As a result, the paper makes four contributions to the psychological contract and careers literature: first, it shows that both individual and organizational career management behaviors are linked to psychological contract fulfillment; second, organizational career management help is associated with affective commitment and job performance; third, psychological contract fulfillment plays a key role in mediating the relationship between career management help and such attitudes and behaviors; and fourth, organizational commitment may mediate between psychological contract fulfillment and individual career management behavior aimed at furthering the career outside the organization. Copyright © 2005 John Wiley & Sons, Ltd.     

Influence of the Interaction of a 900 MHz Signal with Gender on EEG Energy: Experimental Study on the Influence of 900 MHz Radiation on EEG

Summary The effects of electromagnetic fields (EMF) emitted by cellular phones on human electroencephalogram (EEG) were studied during an auditory memory task. The experimental method and the experimental setup are introduced as a credible measurement method of EEG. 19 normal subjects (10 women and 9 men) performed the memory task both with and without exposure to a 900 MHz signal, emitted by a dipole antenna placed near the subjects' head. The energy of the EEG signals was calculated at the time domain. A Fourier transform of the EEG signals was done and the EEG energy was also calculated at the frequency domain. As the Parseval's theorem anticipates the energies were identical. The EEG energy was found concentrated at the four basic bands (α (8–13 Hz), β(14–30 Hz), δ (0–4 Hz) and θ(5–7 Hz)). The primary concern of the present study was the gender related influence of EMF on the spectral energy of EEG. The results show evidence of a strong gender—radiation interaction effect on the EEG energy and on the peak amplitudes within each of the four rhythms. Without radiation the spectral power of males is greater than of females, while under exposure the situation is reversed. Under the influence of EMF the spectral power of the males EEG is decreased while that of the females is increased. In conclusion both the baseline EEG and the changes effected to the EEG power spectrum under the influence of EMF seem to be gender dependent.     

Photo-Fenton treatment of water containing natural phenolic pollutants

Phenolic compounds are known to be present in high concentrations in various types of agro-industrial wastes. As they are highly biorecalcitrant, the possibility of treatment by advanced oxidation processes should be investigated. In this work, six model phenolic compounds (vanillin, protocatechuic acid, syringic acid, p-coumaric acid, gallic acid and L-tyrosine) were chosen for a demonstration of degradation by photo-Fenton reaction, under artificial light in laboratory experiments in Vienna and under sunlight in pilot-plant experiments at the Plataforma Solar de Almería in Spain. All compounds were completely mineralised. No non-degradable intermediates were produced, either in experiments with single substances or in a more complex matrix of a mixture of phenolic compounds. The expected selectivity of the photo-Fenton reaction for aromatic compounds was proven by comparison of the decrease in total organic carbon with the removal of total phenolic content.     

基于FTA和ISM的氯化反应失控火灾爆炸危险性分析

为加强甲烷热氯化工艺过程的安全管理,对氯化反应过程进行危险性分析。本研究介绍了氯甲烷的危害特性以及反应釜失控造成火灾爆炸的危险性,借助事故树分析法中结构重要度的排序获取基本原因事件,在此基础上运用解释结构模型(ISM)对氯化反应过程进行火灾爆炸危险性分析,根据所得基本原因事件的层级划分可得到造成事故发生的直接、间接以及根本原因,最终由ISM分析结果提出针对甲烷热氯化工艺火灾爆炸事故的安全对策措施。     

21世纪人类将面临的环境灾害

环境问题是当今世界面临的重大问题,已引起世界各国高度重视。本文就21世纪威胁人类健康发展一些环境问题进行了简要阐述,以期引起人们的重视和开展研究工作有所借鉴。     

一起"宏观异常"落实事件引发的思考

通过介绍发生在台站附近一次"宏观异常"落实事件,结合当前防震减灾工作的重点,就今后地震台站所面临的新形势,如何贯彻防震减灾总体发展战略和部署,发挥地震监测一线的重要作用作一探讨.本文提出了台站要转变思想,拓展职能,不断增强其基层窗口作用,向现代化、多功能、综合型的模式发展的新思路.     

2, 4-二硝基甲苯在鲤鱼体内的代谢研究

应用水生生物体内实验方法，研究了２，４－二硝基甲苯在鲤鱼肝肠提取物中的生物浓缩及代谢转化过程。半静态条件下，采用３种不同的暴露浓度，测定肝，肠组织的生物浓缩曲线，并同步对肝提取物进行了ＨＰＬＣ检测。