Tracking influent inorganic suspended solids through wastewater treatment plants.

From an experimental and theoretical investigation of the continuity of influent inorganic suspended solids (ISS) along the links connecting the primary settling tank (PST), fully aerobic or N removal activated sludge (AS) and anaerobic and aerobic sludge digestion unit operations, it was found that the influent wastewater (fixed) ISS concentration is conserved through primary sludge anaerobic digestion, activated sludge and aerobic digestion unit operations. However, the measured ISS flux at different stages through a series of wastewater treatment plant (WWTP) unit operations is not equal to the influent ISS flux, because the ordinary heterotrophic organisms (OHO) biomass contributes to the ISS flux by differing amounts depending on the active fraction of the VSS solids at that stage.     

Prominent consequences of role stress: A meta-analytic review.

Role stress has received a lot of research attention in psychological, sociological, and organizational studies over the last several decades. Based on a literature review of about 300 journal articles, this article examines prominent consequences of role stress. Specific focus is on researching differences in relationships between facets of role stress (i.e., role ambiguity, role conflict, and role overload) and frequently cited consequences using techniques of meta-analysis. Findings indicate that each role stress facet has a different relationship with the eight consequences studied. Role stress research can benefit from looking at each facet individually in addition to role stress generally. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

含硫化氢气井钻井过程中的腐蚀因素与防护研究

在含硫气井的钻井过程中对于HRC大于22的钻具钢材除了腐蚀疲劳之外，在pH值小于9的环境中会发生硫化物应力腐蚀破裂，这种破坏比腐蚀疲劳更突然、更快，使钻杆大量损坏。含硫气井在钻井过程中，由于湿硫化氢的出现，常常会出现油管、套管、钻井设备、钻井仪器以及对支持保护管柱的水泥环柱等腐蚀和损坏问题，为此，阐述了湿硫化氢的腐蚀特点、机理，归纳总结了影响腐蚀的因素，综述了如何在这些方面防止其腐蚀，使损失减小，为指导油管、套管防腐工程实践提供了依据。建议在钻井过程中采用碱性钻井液，其pH值可到9或更高(至pH值12)，以减缓或防止钻井过程中电化学从硫化物应力腐蚀破裂；含硫气井用的钻杆应该间歇使用。钻杆停用堆置时间可使其放氢，使钻杆恢复韧性，防止硫化物应力腐蚀断裂。     

Co-digestion of manure and biowaste according to the EC animal by-products regulation and Finnish national regulations.

The objective of this study was to compare methane production and characteristics of digested material in anaerobic digestion concepts according to the Animal By-Products Regulation (ABP-Regulation) of the EC (hygienisation of biowaste for 1 hour at 70 degrees C, particle size < 12 mm) and Finnish national regulations (treatment temperature 55 degrees C, feeding interval 24 h, hydraulic retention time (HRT) 20 d, particle size < 40 mm) and with small variations in treatment methods for treating manure and biowaste. Moreover, the survival of three different salmonella bacteria in these processes was studied. Hygienisation of biowaste prior to digestion at 35 degrees C enhanced methane production by 14-18% compared to similar treatment without hygienisation. The differences in treatment temperature, HRT and hygienisation of biowaste prior to digestion did not significantly affect the characteristics of digested material. The concepts according to the ABP-Regulation and Finnish national regulations were effective in destroying salmonella bacteria to an undetectable level.     

DSP--数字化时代的基因芯片

DSP是当今发展最为迅速的和最有发展前景的技术之一。与普通CPU和MCU相比 ,DSP在数字信号处理方面有着无可比拟的优势 ,特别适合网络、通信、控制等需要进行大量数字信号处理的应用场合。今天DSP已经成为通信、计算机、网络、工业控制以及家用电器等电子产品中不可或缺的基础器件 ,DSP在通信、计算机、网络、工业控制以及消费类电子产品等领域有着非常广泛的应用 ,本文阐述了DSP的特点、应用和市场以及DSP技术的发展前景。     

On the effect of spatial variances in historical rainfall time series to CSO performance evaluation.

Historical, high-resolution rain series are the backbone of modern combined sewer overflow (CSO) structure design. These rain series are the input to the computational estimation of the performance of the measures with respect to CSO pollution abatement. However, those historical precipitation measurements are available at only a few locations. Frequently rain series have to be used from gauging stations at a significant distance. In order to judge and to compensate for this influence an estimate between rain characteristics and combined sewer outflow (CSO) performance indicators would be useful. In this paper such correlations have been sought for a collection of 37 rain series covering large areas of Europe. It was found that the mean annual rain volume can explain most of the variances for the performance indicators Number of overflows and CSO volume. For explaining the spatial differences in the efficiency of the CSO structure another rain characteristic, i.e. the maximum event with a return period of one year, is to be used.     

游梁式抽油机间歇供电装置的研制与应用

针对游梁抽油机电动机效率低和井场窃电问题,研制了具有节电和防井场窃电功能的游梁抽油机调压+间歇供电装置。该装置通过控制可控硅的导通角实现在电动机做功期调压供电,在电动机发电期不供电。分析了间歇供电对电动机、抽油机和电网的影响;根据现场实测数据分析了该装置的节电效果及现场应用情况。该装置节电效果显著,能防止井场窃电,可用于对游梁抽油机电动机的长期驱动。     

On the use of 2-D coding techniques for ECG signals.

This paper discusses the convenience of using two-dimensional (2-D) coding techniques for the compression of electrocardiogram (ECG) signals. These signals present a very clear periodicity that can be exploited by the use of a 2-D time/frequency transform to decorrelate it as much as possible. A brief theoretical approach is given to justify the use of this technique, and a comparison is made between a 2-D and a one-dimensional (1-D) uniform quantization scenarios. The influence of the error as well as the frame size on the estimation of the fundamental period is studied.     

Alumina-supported catalysts for propane oxidative dehydrogenation from mixed VXM(6−X)O19 (M=W, Mo) hexametalate precursors

γ-Al₂O₃ supported vanadium oxides were modified by tungsten and molybdenum oxides in order to improve dispersion and selectivity towards olefins in propane oxidative dehydrogenation (ODH). Both vanadium–tungsten and vanadium–molybdenum catalysts were obtained by adsorption of mixed isopolyanions (VW₅O₁₉⁵⁻, V₂W₄O₁₉⁴⁻, VMo₅O₁₉⁵⁻ and V₂Mo₄O₁₉⁴⁻) from aqueous solutions. The isopolyanion solutions were characterized by UV-Vis and ⁵¹V NMR spectroscopy. Vanadium, vanadium–tungsten and vanadium–molybdenum precursors and catalysts were also characterized by UV-Vis (diffuse reflectance) and solid state ⁵¹V NMR spectroscopy. An improved selectivity to propene in the presence of tungsten and molybdenum in VO_x/γ-Al₂O₃ was observed and attributed to dilution of vanadium by tungsten or molybdenum oxides on the γ-Al₂O₃ surface.