Cristalização assistida por destilação por membranas aplicada ao reuso de água: comparação com outros métodos de reuso, análise do processo e projeto hierárquico de processo.

No presente trabalho foram avaliados processos alternativos de dessalinização visando a recuperação e reuso da água contida em salmouras concentradas, sendo o processo de cristalização assistida por destilação por membranas (MDC) investigado com profundidade. Foi desenvolvido um modelo diferencial para o processo de destilação por membranas por contato direto (DCMD), contemplando métodos termodinâmicos rigorosos para sistemas aquosos de eletrólitos fortes, bem como mecanismos de transferência de calor e massa e efeitos de polarização de temperatura e concentração característicos deste processo de separação. Com base em simulações realizadas a partir do modelo matemático assim desenvolvido, foram investigados os principais parâmetros que influenciam o projeto de um módulo de membranas para DCMD. O modelo foi posteriormente estendido com equações de balanço de massa e energia adicionais para incluir a operação de cristalização e desta forma representar o processo de MDC. De posse dos resultados das simulações e do modelo estendido, foi desenvolvido um método hierárquico para o projeto de processos de MDC, com o objetivo de conferir características de rastreabilidade e repetibilidade a esta atividade. Ainda a partir do modelo MDC foram discutidos aspectos importantes em MDC como a possibilidade de nucleação e crescimento de cristais sobre a superfície das membranas, bem como o comportamento do processo com sais com diferentes características de solubilidade e largura da zona metaestável. Verificou-se que para sais cuja solubilidade varia muito pouco com a temperatura e que possuem zona metaestável com pequena largura, caso do NaCl, a operação com resfriamento no cristalizador não é viável pois aumenta excessivamente o consumo energético do processo, sendo nesses casos preferível a operação \"isotérmica\" - sem resfriamento no cristalizador - e o convívio com a possibilidade de nucleação no interior do módulo. No extremo oposto, observou-se que para sais com grande variabilidade da solubilidade com a temperatura, um pequeno resfriamento no cristalizador é suficiente para garantir condições de subsaturação no interior do módulo, sem grande ônus energético para o processo. No caso de sais com pequena variabilidade da solubilidade com a temperatura, mas com largura da zona metaestável elevada, existe certo ônus energético para a operação com resfriamento do cristalizador, porém não tão acentuado como no caso de sais com zona metaestável estreita. Foi proposto um fluxograma alternativo para o processo de MDC, onde foi introduzido um circuito de pré-concentração da alimentação antes do circuito de cristalização, para o caso de alimentação com soluções muito diluídas. Este esquema proporcionou um aumento do fluxo permeado global do processo e consequentemente uma redução na área total de membrana requerida. Verificou-se que através do processo com préconcentração da alimentação de 5% até 10% em massa - no caso de dessalinização de uma solução de NaCl - foi possível reduzir-se a área total da membrana em 27,1% e o consumo energético específico do processo em 10,6%, quando comparado ao processo sem pré-concentração. Foram desenvolvidas ferramentas úteis para o projeto de processos de dessalinização por MDC em escala industrial.

Extended- and point-source radiometric program.

Imprint on cover: [Washington?] Civil Effects Test Operations [Office] U. S. Atomic Energy Commission.

Novel renoprotective actions of erythropoietin: New uses for an old hormone

Erythropoietin (EPO) has been used widely for the treatment of anaemia associated with chronic kidney disease and cancer chemotherapy for nearly 20 years. More recently, EPO has been found to interact with its receptor (EPO-R) expressed in a large variety of non-haematopoietic tissues to induce a range of cytoprotective cellular responses, including mitogenesis, angiogenesis, inhibition of apoptosis and promotion of vascular repair through mobilization of endothelial progenitor cells from the bone marrow. Administration of EPO or its analogue, darbepoetin, promotes impressive renoprotection in experimental ischaemic and toxic acute renal failure, as evidenced by suppressed tubular epithelial apoptosis, enhanced tubular epithelial proliferation and hastened functional recovery. This effect is still apparent when administration is delayed up to 6 h after the onset of injury and can be dissociated from its haematological effects. Based on these highly encouraging results, at least one large randomized controlled trial of EPO therapy in ischaemic acute renal failure is currently underway. Preliminary experimental and clinical evidence also indicates that EPO may be renoprotective in chronic kidney disease. The purpose of the present article is to review the renoprotective benefits of different protocols of EPO therapy in the settings of acute and chronic kidney failure and the potential mechanisms underpinning these renoprotective actions. Gaining further insight into the pleiotropic actions of EPO will hopefully eventuate in much-needed, novel therapeutic strategies for patients with kidney disease.

Mobile phone and e-government in Turkey:practices and technological choices at the cross-road

Enhanced data services through mobile phones are expected to be soon fully transactional and embedded within future mobile consumption practices. While private services will surely continue to take the lead, others such as government and NGOs will become more prominent m-players. It is not yet sure which form of technological standards will take the lead including enhance SMS based operations or Internet based specifically developed mobile phone applications. With the introduction of interactive transactions via mobile phones, currently untapped segment of the populations (without computers) have the potential to be accessed. Our research, as a reflection of the current market situation in an emerging country context, in the case of mobile phones analyzes the current needs or emergence of dependencies regarding the use of m/e-government services from the perspective of municipality officers. We contend that more research is needed to understand current preparatory bottlenecks and front loading activities to be able to encourage future intention to use e-government services through mobile phone technologies. This study highlights and interprets the current emerging practices and praxis for consuming m-government services within government.

Workers' understanding of chemical risks: electroplating case study

BACKGROUND: There is limited research concerning how small companies in particular, respond to health and safety messages. AIMS: To understand individuals' knowledge and beliefs about chemical risks and to compare these with those of experts. METHODS: The use of chromic acid in particular, and also other chemicals associated with chrome plating were studied. All chromium plating firms were based in the West Midlands. The methodology involved initial face to face interviews (n = 21) with chromium platers, structured questionnaires (n = 84) to test the prevalence of beliefs identified in the interviews, an expert questionnaire, and a workshop to discuss findings. The responses of platers were compared with those of occupational health and safety experts. RESULTS: Although chromium platers appeared to understand the short term adverse effects of the chemicals to which they are exposed, their understanding of long term, or chronic effects appeared to be incomplete. They had good knowledge of acute effects based primarily on experience. Platers were aware of the hazardous nature of the chemicals with which they work, but did not draw distinction between the terms "hazards" and "risks". They had difficulties articulating the effects of the chemicals and how exposure might occur; although it is inappropriate to equate this with lack of knowledge. A significant minority of platers displayed deficiencies in understanding key technical terms used in Safety Data Sheets. CONCLUSIONS: This study provides a method which can be used to gain some understanding of workers' knowledge and beliefs about risks that they are exposed to in the workplace. The study also identifies gaps between the platers' knowledge and beliefs and those of experts. New risk information needs to be designed which addresses the information needs of platers using language that they understand.

The impact of external market factors on operational practices and performance of companies

The links between operational practices and performance are well studied in the literature, both theoretically and empirically. However, mostly internal factors are inspected more closely as the basis of operational performance, even if the impact of external, environmental factors is often emphasized. Our research fills a part of this existing gap in the literature. We examine how two environmental factors, market dynamism and competition impact the use of some operational practices (such as quality improvement, product development, automation, etc.) and the resulting operations and business performance. The method of path analysis is used. Data were acquired through an international survey (IMSS – International Manufacturing Strategy Survey), which was executed in 2005, in 23 participating countries in so called "innovative" industries (ISIC 28-35) with a sample of 711 firms. Results show that both market dynamism and competition have large impact on business performance, but the indirect effects, through operations practices are rather weak compared to direct ones. The most influential practices are from the area of process and control, and quality management.

New business strategies of football clubs

The study investigates new strategies of football clubs in function of last few years’ trends in European football leagues. There were many changes in international professional football during the last 10-15 years that had significant effect on the success of certain clubs. We show empirical evidences about these effects based on data about revenues, transfer balance, financial and sport successes. We focus on Western European leagues and classify clubs based on their business and sport strategies.

Effects of dredging operations on sediment quality: contaminant mobilization in dredged sediments from the Port of Santos, SP, Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effects of temperament and acclimation to handling on feedlot performance of Bos taurus feeder cattle originated from a rangeland-based cow-calf system

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Effects of dredging operations on sediment quality: contaminant mobilization in dredged sediments from the Port of Santos, SP, Brazil

Background, aim, and scope Contaminated sediments are a worldwide problem, and mobilization of contaminants is one of the most critical issues in environmental risk assessment insofar as dredging projects are concerned. The investigation of how toxic compounds are mobilized during dredging operations in the channel of the Port of Santos, Brazil, was conducted in an attempt to assess changes in the bioavailability and toxicity of these contaminants.Materials and methods Bulk sediment samples and their interstitial waters and elutriates were subjected to chemical evaluation and ecotoxicological assessment. Samples were collected from the channel before dredging, from the dredge's hopper, and from the disposal site and its surroundings.Results The results indicate that the bulk sediments from the dredging site are contaminated moderately with As, Pb, and Zn and severely with Hg, and that polycyclic aromatic hydrocarbon (PAH) concentrations are relatively high. Our results also show a 50% increase in PAH concentrations in suspended solids in the water collected from the hopper dredge. This finding is of great concern, since it refers to the dredge overflow water which is pumped back into the ecosystem. Acute toxicity tests on bulk sediment using the amphipod Tiburonella viscana showed no toxicity, while chronic tests with the sea urchin Lytechinus variegatus showed toxicity in the interstitial waters and elutriates. Results are compared with widely used sediment quality guidelines and with a sediment quality assessment scheme based on various lines of evidence.Conclusions The data presented here indicate that the sediments collected in this port show a certain degree of contamination, especially those from the inner part of the channel. The classification established in this study indicated that sediments from the dredged channel are impacted detrimentally and that sea disposal may disperse contaminants. According to this classification, the sediments are inappropriate for disposal at sea. It should be emphasized that the poor quality of fine sediments discharged from the hopper dredge in the overflow process can recontaminate the environment.Recommendations and perspectives These findings will help to underpin improved planning of management strategies for dredging operations and sediment disposal in Brazil and other countries.

In vivo skin effects of a dimethylaminoethanol (DMAE) based formulation

Dimethylaminoethanol (DMAE) has been used in anti-aging formulations but few scientifically based data address its efficacy. The aim of this study was to evaluate the effects of DMAE-based formulations on hairless mice and human skin. Formulations containing with or without DMAE were applied to the dorsum of hairless mice. Histopathological and histometric evaluations were carried out after seven days. Formulations were also applied to the ventral forearm and the lateral periocular area of human volunteers. Stratum corneum water content and skin mechanical properties were analyzed using Corneometer and Cutometer, before and after a single and repeated application. Histometric evaluations showed that formulations with or without DMAE increased the viable epidermis thickness, but only the DMAE-supplemented formulation led to increased dermal thickness. DMAE also induced increase in collagen fiber thickness, which was observed in the histopathological study. After the single and the 8-week period application on human skin, formulations with and without DMAE enhanced the stratum corneum water content in the forearm skin. Mechanical properties were not significantly modified. So, we can suggest that DMAE action is related to its effects on the dermis as observed in the histopathological and histometric studies and showed hydration effects on skin.

The effects of Australian tall poppy attitudes on American value based leadership theory

A survey study of twenty-two Australian CEOs and their subordinates assessed relationships between Australian leader motives, Australian value based leader behaviour, subordinate tall poppy attitudes and subordinate commitment, effectiveness, motivation and satisfaction (CEMS). On the whole, the results showed general support for value based leadership processes. Subsequent regression analyses of the second main component of Value Based Leadership Theory, value based leader behaviour, revealed that the collectivistic, inspirational, integrity and visionary behaviour sub-scales of the construct were positively related with subordinate CEMS. Although the hypothesis that subordinate tall poppy attitudes would moderate value based leadership processes was not clearly supported, subsequent regression analyses found that subordinate tall poppy attitudes were negatively related with perceptions of value based leader behaviour and CEMS. These findings suggest complex relationships between the three constructs, and the proposed model for the Australian context is accordingly amended. Overall, the research supports the need to consider cultural-specific attitudes in management development.

Perceived self-other differences in persuasibility: the effects of interpersonal and group-based similarity

Two experiments examined the effects of interpersonal and group-based similarity on perceived self-other differences in persuasibility (i.e. on third-person effects, Davison, 1983). Results of Experiment 1 (N=121), based on experimentally-created groups, indicated that third-person perceptions with respect to the impact of televised product ads were accentuated when the comparison was made with interpersonally different others. Contrary to predictions, third-person perceptions were not affected by group-based similarity (i.e. ingroup or outgroup other). Results of Experiment 2 (N = 102), based an an enduring social identity, indicated that both interpersonal and group-based similarity moderated perceptions of the impact on self and other of least-liked product ads. Overall, third-person effects were more pronounced with respect to interpersonally dissimilar others. However, when social identity was salient, information about interpersonal similarity of the target did not affect perceived self-other differences with respect to ingroup targets. Results also highlighted significant differences in third-person perceptions according to the perceiver's affective evaluation of the persuasive message. (C) 1998 John Wiley & Sons, Ltd.

Modelling the Distribution of Ischaemic Stroke-Specific Survival Time Using an EM-based Mixture Approach with Random Effects Adjustment

A two-component survival mixture model is proposed to analyse a set of ischaemic stroke-specific mortality data. The survival experience of stroke patients after index stroke may be described by a subpopulation of patients in the acute condition and another subpopulation of patients in the chronic phase. To adjust for the inherent correlation of observations due to random hospital effects, a mixture model of two survival functions with random effects is formulated. Assuming a Weibull hazard in both components, an EM algorithm is developed for the estimation of fixed effect parameters and variance components. A simulation study is conducted to assess the performance of the two-component survival mixture model estimators. Simulation results confirm the applicability of the proposed model in a small sample setting. Copyright (C) 2004 John Wiley Sons, Ltd.