Improving mental health status and coping abilities for long‐term unemployed youth using cognitive‐behaviour therapy based training interventions

This paper reports on immediate and long‐term well‐being outcomes for a group of long‐term unemployed youth who attended specially devised training courses based on the cognitive‐behaviour therapy (CBT) model. The courses were aimed specifically at improving the mental health of participants, and providing them with coping skills to deal better with the negative consequences of prolonged unemployment. Results for participants were compared with a waiting‐list, control group. Outcomes investigated were well‐being (psychological distress, self‐esteem, positive and negative affect), and coping behaviours (social support, self care, recreation, and cognitive coping strategies). Behavioural plasticity effects were also examined by comparing outcomes for participants who had higher distress scores prior to the course with participants who reported lower scores at that time. Immediate benefits were identified for both mental health and coping behaviours, and many of these benefits persisted into the long term. Participants with higher levels of pre‐course psychological distress improved more than their low distressed counterparts, supporting the behavioural plasticity hypothesis. Copyright © 1999 John Wiley & Sons, Ltd.     

燃煤电厂典型超低排放除尘技术组合下的尘排放特性

为研究典型超低排放除尘技术组合下的尘排放特性,梳理了目前超低排放除尘技术改造的主流技术路线,归纳出典型的7种改造技术路线。依据典型的改造技术路线,选择了27台在2015—2017年完成改造的燃煤发电机组,并对其烟尘排放进行长期的连续监测,根据机组长期运行的排放表现对典型超低排放除尘技术路线的实际减排效果进行量化对比分析。结果表明,7种除尘改造技术路线均可达到控制烟尘排放浓度在10 mg·m~(-3)以下的超低排放标准,其中路线6改造后尘浓度控制在2 mg·m~(-3)以下。对减排效率的研究表明,各技术路线改造后的减排效率均可达到99.97%以上,计算得到机组的平均排放因子为0.025 7 kg·t~(-1)(95%置信区间0.025 4～0.026 1 kg·t~(-1)),其中路线6的排放因子最低,为0.008 6 kg·t~(-1)(95%置信区间0.008 4～0.008 8 kg·t~(-1))。     

The Effect of Fiber Pretreatment and Compatibilizer on Mechanical and Physical Properties of Flax Fiber-Polypropylene Composites

Recently, investigations have been conducted on the use of natural fibers as reinforcement in low-melting point thermoplastics to improve mechanical properties of composites. However, due to some limitations of natural fibers, composite formulation and processing parameters must be controlled to produce a product with improved properties. This study was conducted to investigate the influence of flax fiber loading, use of compatibilizer and pretreatment on physical and mechanical properties of compression-molded composite. In this study, untreated and treated (sodium hydroxide-treated and mild-bleached flax fibers) fibers at 15% and 30% of the total product mass were used in formulations. To investigate the effect of compatibilizer on product properties, maleic anhydride grafted polypropylene (MAPP) was added at 5% by mass in the formulations. After extrusion of composites formulations, they were formed using compression molding. Results indicated that using flax fiber in composites without pretreatment and compatibilizer could result into products with inferior physical and mechanical properties; this could be compensated by the use of a compatibilizer. However, the use of compatibilizer had some negative effects on some other physical properties like color and melt flow index (MFI).     

Impediments and Solutions to Sustainable,Watershed-Scale Urban Stormwater Management: Lessons from Australia and the United States

In urban and suburban areas, stormwater runoff is a primary stressor on surface waters. Conventional urban stormwater drainage systems often route runoff directly to streams and rivers, thus exacerbating pollutant inputs and hydrologic disturbance, and resulting in the degradation of ecosystem structure and function. Decentralized stormwater management tools, such as low impact development (LID) or water sensitive urban design (WSUD), may offer a more sustainable solution to stormwater management if implemented at a watershed scale. These tools are designed to pond, infiltrate, and harvest water at the source, encouraging evaporation, evapotranspiration, groundwater recharge, and re-use of stormwater. While there are numerous demonstrations of WSUD practices, there are few examples of widespread implementation at a watershed scale with the explicit objective of protecting or restoring a receiving stream. This article identifies seven major impediments to sustainable urban stormwater management: (1) uncertainties in performance and cost, (2) insufficient engineering standards and guidelines, (3) fragmented responsibilities, (4) lack of institutional capacity, (5) lack of legislative mandate, (6) lack of funding and effective market incentives, and (7) resistance to change. By comparing experiences from Australia and the United States, two developed countries with existing conventional stormwater infrastructure and escalating stream ecosystem degradation, we highlight challenges facing sustainable urban stormwater management and offer several examples of successful, regional WSUD implementation. We conclude by identifying solutions to each of the seven impediments that, when employed separately or in combination, should encourage widespread implementation of WSUD with watershed-based goals to protect human health and safety, and stream ecosystems.     

An Investigation Into the Mechanism by Which Synthetic Zeolites Reduce Labile Metal Concentrations in Soils

The addition of synthetic zeolites and similar materials to metal contaminated soils has been shown to reduce soil phytotoxicity and to improve the quality of plant growth on such amended soils. To gain an understanding of the mechanism by which the phytotoxicity of contaminated soils is reduced when treated with synthetic zeolites, sequential extraction procedures and soil solution techniques have been used to identify changes associated with metal speciation in amended soils. Sequential extraction data and changes in soil solution composition are presented for three different contaminated soils, amended with three synthetic zeolites (P, 4A and Y) at concentrations of 0.5%, 1% and 5% w/w, or lime at 1%. The soils were collected from the site of a metal refinery, an old lead zinc mine spoil tip and from a field which had been treated with sewage sludge. After incubation of the zeolite treated soils for between one and three months, results showed a reduction in the metal content of the ammonium acetate fraction between 42% and 70%, depending on soil, zeolite and rate of addition, compared with the unamended soils. In addition, soil solution experiments indicated that synthetic zeolite amendments were more efficient at reducing metal content than comparable lime treatment. The mechanism by which synthetic zeolites reduce metal bioavailability in contaminated soils is discussed and compared to other amendments.     

Validation of a standardized portable fluorescence method for determining trace beryllium in workplace air and wipe samples

Beryllium is widely used in industry for its unique properties; however, occupational exposure to beryllium particles can cause potentially fatal disease. Consequently, exposure limits for beryllium particles in air and action levels on surfaces have been established to reduce exposure risks for workers. Field-portable monitoring methods for beryllium are desired in order to facilitate on-site measurement of beryllium in the workplace, so that immediate action can be taken to protect human health. In this work, a standardized, portable fluorescence method for the determination of trace beryllium in workplace samples, i.e., air filters and dust wipes, was validated through intra- and inter-laboratory testing. The procedure entails extraction of beryllium in 1% ammonium bifluoride (NH(4)HF(2), aqueous), followed by fluorescence measurement of the complex formed between beryllium ion and hydroxybenzoquinoline sulfonate (HBQS). The method detection limit was estimated to be less than 0.02 microg Be per air filter or wipe sample, with a dynamic range up to greater than 10 microg. The overall method accuracy was shown to satisfy the accuracy criterion (A< or = +/-25%) for analytical methods promulgated by the US National Institute for Occupational Safety and Health (NIOSH). Interferences from numerous metals tested (in >400-fold excess concentration compared to that of beryllium) were negligible or minimal. The procedure was shown to be effective for the dissolution and quantitative detection of beryllium extracted from refractory beryllium oxide particles. An American Society for Testing and Materials (ASTM) International voluntary consensus standard based on the methodology has recently been published.     

用GC-三级四极杆MS/MS一次进样筛选鱼和飞灰样品基质中四至八氯代PCDD/Fs的方法

用高分离能力的气相色谱-高分辨质谱(HRGC-HRMS)核实二噁英/呋喃是一项昂贵又费时的分析工作,需要高素质的仪器操作人员,而在认证分析前采用筛选法检查样品是检测不出还是浓度超出HRGC-HRMS方法定量范围,可以大大地减少HRGC-HRMS实验室的工作负荷.最新提供的信息表明约10%筛选过的样品需用HRGC-HRMS认证/核实.有些GC/MS/MS方法需要多次进样以获得有毒和无毒的PCDD/Fs,或用功能变换法[1-4]可以确保检测出所有的有毒的2,3,7,8-氯代PCDD/Fs,但损失某些无毒的PCDD/Fs(2,3,7,8氯代PCDD/Fs除外).