Wastewater treatment with submerged fixed bed biofilm reactor systems--design rules, operating experiences and ongoing developments.

Wastewater treatment systems using bio-films that grow attached to a support media are an alternative to the widely used suspended growth activated sludge process. Different fixed growth biofilm reactors are commercially used for the treatment of municipal as well as industrial wastewater. In this paper a fairly new fixed growth biofilm system, the submerged fixed bed biofilm reactor (SFBBR), is discussed. SFBBRs are based on aerated submerged fixed open structured plastic media for the support of the biofilm. They are generally operated without sludge recirculation in order to avoid clogging of the support media and problems with the control of the biofilm. Reactor and process design considerations for these reactors are reviewed. Measures to ensure the development and maintenance of an active biofilm are examined. SFBBRs have been applied successfully to small wastewater treatment plants where complete nitrification but no high degree of denitrification is necessary. For the pre-treatment of industrial wastewater the use of SFBBRs is advantageous, especially in cases of wastewater with high organic loading or high content of compounds with low biodegradability. Performance data from exemplary commercial plants are given. Ongoing research and development efforts aim at achieving a high simultaneous total nitrogen (TN) removal of aerated SFBBRs and at improving the efficiency of TN removal in anoxic SFBBRs.     

Raising voice, risking retaliation: Events following interpersonal mistreatment in the workplace.

This study advances the literature on workplace deviance, addressing retaliation victimization in the context of interpersonal mistreatment. Using survey data from 1,167 public-sector employees, the authors investigated experiences of work retaliation victimization and social retaliation victimization among employees who have vocally resisted interpersonal mistreatment. Regression analyses suggest that different victim voice mechanisms trigger different forms of retaliation, depending on the social positions of the mistreatment victim and instigator. Discriminant function analyses demonstrate lower professional, psychological, and physical well-being among mistreated employees who have been further victimized with retaliation. These analyses also reveal health-related costs associated with victim silence--that is, enduring mistreatment without voicing resistance. Results are interpreted in light of theory on power, emotions, and justice in organizations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

CMOS analog MAP decoder for (8,4) Hamming code

Design and test results for a fully integrated translinear tail-biting MAP error-control decoder are presented. Decoder designs have been reported for various applications which make use of analog computation, mostly for Viterbi-style decoders. MAP decoders are more complex, and are necessary components of powerful iterative decoding systems such as turbo codes. Analog circuits may require less area and power than digital implementations in high-speed iterative applications. Our (8, 4) Hamming decoder, implemented in an AMI 0.5-/spl mu/m process, is the first functioning CMOS analog MAP decoder. While designed to operate in subthreshold, the decoder also functions above threshold with a small performance penalty. The chip has been tested at bit rates up to 2 Mb/s, and simulations indicate a top speed of about 10 Mb/s in strong inversion. The decoder circuit size is 0.82 mm/sup 2/, and typical power consumption is 1 mW at 1 Mb/s.     

CDMA with Partitioned Spreading

An enhancement to code-division multiple access (CDMA) is proposed whereby the signature sequences are partitioned into sections, which are interleaved before transmission. A multistage receiver successively forms soft-bit estimates based on the received sections, which are used to reduce the interference in subsequent stages via signal cancellation. This significantly increases the user loads which can be supported as the system effectively suppresses interference, with a marked threshold effect below which practically single user performance is achieved. The number of stages required is typically small and independent of the system size, that is the number of users. Furthermore, it is shown that the proposed multistage demodulation is insensitive to variations in the received powers.     

Personal and workgroup incivility: Impact on work and health outcomes.

This article develops a theoretical model of the impact of workplace incivility on employees' occupational and psychological well-being. In Study 1, the authors tested the model on 1,158 employees, finding that satisfaction with work and supervisors, as well as mental health, partially mediated effects of personal incivility on turnover intentions and physical health; this process did not vary by gender. Study 2 cross-validated and extended these results on an independent sample of 271 employees, showing negative effects of workgroup incivility that emerged over and above the impact of personal incivility. In both studies, all results held while controlling for general job stress. Implications for organizational science and practice are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

N'-methylniphimycin, a novel minor congener of niphimycin from Streptomyces spec. 57-13

A novel natural niphimycin analog, N'-methylniphimycin was isolated from the culture broth of the Streptomyces spec. 57-13. The chemical constitution was elucidated from the physico-chemical properties, NMR techniques and mass spectrometry to be a 36-membered macrolide related to azalomycin F5a, shurimycin B and RS-22C. N'-methylniphimycin displayed moderate activity against some yeasts and filamentous fungi.     

Great Expectations: "I'm Losing 25% of My Weight No Matter What You Say".

This study investigated whether informing obese individuals that they would lose only modest amounts of weight would lead them to adopt more realistic weight loss expectations. At a screening interview, 53 obese women reported that they expected to lose the equivalent of 28% of their initial weight during 1 year of treatment with the medication sibutramine. Prior to beginning treatment, participants were informed, both verbally and in writing, that they could expect to lose 5% to 15% of initial weight, the loss typically induced by current behavioral and pharmacologic approaches. This information, however, had little impact on their weight loss expectations when assessed on subsequent occasions. Results are discussed in terms of the origins, clinical significance, and potential malleability of obese individuals' weight loss expectations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Identifying Unknown Enzyme–Substrate Pairs from the Cellular Milieu with Native Mass Spectrometry

The enzyme–substrate complex is inherently transient, rendering its detection difficult. In our framework designed for bisubstrate systems—isotope‐labeled, activity‐based identification and tracking (IsoLAIT)—the common substrate, such as S‐adenosyl‐l ‐methionine (AdoMet) for methyltransferases, is replaced by an analogue (e.g., S‐adenosyl‐l ‐vinthionine) that, as a probe, creates a tightly bound [enzyme ? substrate ? probe] complex upon catalysis by thiopurine‐S‐methyltransferase (TPMT, EC 2.1.1.67). This persistent complex is then identified by native mass spectrometry from the cellular milieu without separation. Furthermore, the probe's isotope pattern flags even unknown substrates and enzymes. IsoLAIT is broadly applicable for other enzyme systems, particularly those catalyzing group transfer and with multiple substrates, such as glycosyltransferases and kinases.     

An open-source population balance modeling framework for the simulation of polydisperse multiphase flows

Polydispersity is a challenging feature of many industrial and environmental multiphase flows, influencing all related transfer and transport processes. Besides their size, the fluid or solid particles may be distributed with respect to other properties such as their velocity or shape. Here, a population balance model based on the method of classes is combined with a multifluid solver within the open source computational fluid dynamics library OpenFOAM. The model allows for tracking the evolution of one or more size-conditioned secondary properties. It is applied to two different problems, the first being bubbly flow of air and water in a vertical pipe, where considering the velocity as a secondary property allows to resolve the size-dependent radial segregation. The second application is the gas phase synthesis of titania powder, where non-spherical particle aggregates appear whose shape is modeled through a collision diameter, leading to an improved prediction of the size distribution.