924 resultados para Reasonable Lenght of Process


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Thesis (Master, Civil Engineering) -- Queen's University, 2016-06-01 00:03:02.939

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Thesis (Master's)--University of Washington, 2016-06

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One of the key environmental concerns about shrimp farming is the discharge of waters with high levels of nutrients and suspended solids into adjacent waterways. In this paper we synthesize the results of our multidisciplinary research linking ecological processes in intensive shrimp ponds with their downstream impacts in tidal, mangrove-lined creeks. The incorporation of process measurements and bioindicators, in addition to water quality measurements, improved our understanding of the effect of shrimp farm discharges on the ecological health of the receiving water bodies. Changes in water quality parameters were an oversimplification of the ecological effects of water discharges, and use of key measures including primary production rates, phytoplankton responses to nutrients, community shifts in zooplankton and delta(15)N ratios in marine plants have the potential to provide more integrated and robust measures. Ultimately, reduction in nutrient discharges is most likely to ensure the future sustainability of the industry. (C) 2003 Elsevier Ltd. All rights reserved.

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Background: Aflifle a growing literature supports the effectiveness of physical activity interventions delivered in the primary care setting, few studies have evaluated efforts to increase physician counseling on physical activity during routine practice (i.e., outside the context of controlled research). This paper reports the results of a dissemination trial of a primary care-based physical activity counseling intervention conducted within the context of a larger, multi-strategy, Australian community-based, physical activity intervention, the 10,000 Steps Rockhampton Project. Methods: All 23 general practices and 66 general practitioners (GPs, the Australian equivalent of family physicians) were invited to participate. Practice visits were made to consenting practices during which instruction in brief physical activity counseling was offered, along with physical activity promotion resources (print materials and pedometers). The evaluation, guided by the RE-AIM framework, included collection of process data, as well as pre-and post-inteivention data from a mailed GP survey, and data from the larger project's random-digit-dialed, community-based, cross-sectional telephone survey that was conducted in Rockhampton and a comparison community, Results: Ninety-one percent of practices were visited by 10,000 Steps staff and agreed to participate, with 58% of GPs present during the visits. General practitioner survey response rates were 67% (n =44/66 at baseline) and 71% (n =37/52, at 14-month follow-up). At follow-up, 62% had displayed the poster, 81% were using the brochures, and 70% had loaned pedometers to patients, although the number loaned was relatively small. No change was seen in GP self-report of the percentage of patients counseled on physical activity. However, data from the telephone surveys showed a 31% increase in the likelihood of recalling GP advice on physical activity in Rockhampton (95% confidence interval [CI]=1.11-1.54) compared to a 16% decrease (95% CI=0.68-1.04) in the comparison community. Conclusions: This dissemination study achieved high rates of GP uptake, reasonable levels of implementation, and a significant increase in the number of community residents counseled on physical activity. These results suggest that evidence-based primary care physical activity counseling protocols can be translated into routine practice, although the initial and ongoing investment of time to develop partnerships with relevant healthcare organizations, and the interest generated by the overall 10,000 Steps program should not be underestimated. ((C) 2004 American journal of Preventive Medicine.

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Attention is drawn to the feasibility of using isothermal calorimetry for the characterization of enzyme reactions under conditions bearing greater relevance to the crowded biological environment, where kinetic parameters are likely to differ significantly from those obtained by classical enzyme kinetic studies in dilute solution. An outline of the application of isothermal calorimetry to the determination of enzyme kinetic parameters is followed by considerations of the nature and consequences of crowding effects in enzyme catalysis. Some of those effects of thermodynamic non-ideality are then illustrated by means of experimental results from calorimetric studies of the effect of molecular crowding on the kinetics of catalysis by rabbit muscle pyruvate kinase. This review concludes with a discussion of the potential of isothermal calorimetry for the experimental determination of kinetic parameters for enzymes either in biological environments or at least in media that should provide reasonable approximations of the crowded conditions encountered in vivo. Copyright (C) 2004 John Wiley Sons, Ltd.

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This paper presents results on the preparation of microcapsules containing liquid organosilica, and their co-deposition with copper in an acidic copper electrolyte onto a carbon steel cathode to form a copper/microcapsule composite coating. Microscopic analyses of the surface and the cross-section of the coating confirm the incorporation of the liquid-containing microcapsules in the coating layer. The influence of microcapsules in the electrolyte on the cathode polarization, as well as that of process conditions on the microcapsule inclusion, is also discussed. (C) 2004 Kluwer Academic Publishers.

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Granulation is one of the fundamental operations in particulate processing and has a very ancient history and widespread use. Much fundamental particle science has occurred in the last two decades to help understand the underlying phenomena. Yet, until recently the development of granulation systems was mostly based on popular practice. The use of process systems approaches to the integrated understanding of these operations is providing improved insight into the complex nature of the processes. Improved mathematical representations, new solution techniques and the application of the models to industrial processes are yielding better designs, improved optimisation and tighter control of these systems. The parallel development of advanced instrumentation and the use of inferential approaches provide real-time access to system parameters necessary for improvements in operation. The use of advanced models to help develop real-time plant diagnostic systems provides further evidence of the utility of process system approaches to granulation processes. This paper highlights some of those aspects of granulation. (c) 2005 Elsevier Ltd. All rights reserved.

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Research techniques and a methodology have been developed that enable the reduction kinetics of molten lead smelting slags with solid carbon to be studied. The rates of reduction of PbO-FeO-Fe2O3-CaO-SiO2 slags with carbon have been measured for a range of slag compositions for PbO concentrations between 3 and 100 weight percent, and temperatures between 1423 and 1573 K. The reduction rates were determined for both graphite and coke. Within the range of process conditions examined, it has been shown that the reaction rates are almost independent of carbon reactivity, SiO2/CaO and SiO2/Fe ratio in the range of compositions investigated and are not influenced by the presence of sulphur in the slag.The apparent first order rate constants for oxygen removal increase with increasing PbO concentration and oxygen activity in the slag. The data indicate that the rate limiting reaction step for the reduction of lead slags with solid carbon is the chemical reaction at the gas/slag interface.

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The aim of this report is to describe the use of WinBUGS for two datasets that arise from typical population pharmacokinetic studies. The first dataset relates to gentamicin concentration-time data that arose as part of routine clinical care of 55 neonates. The second dataset incorporated data from 96 patients receiving enoxaparin. Both datasets were originally analyzed by using NONMEM. In the first instance, although NONMEM provided reasonable estimates of the fixed effects parameters it was unable to provide satisfactory estimates of the between-subject variance. In the second instance, the use of NONMEM resulted in the development of a successful model, albeit with limited available information on the between-subject variability of the pharmacokinetic parameters. WinBUGS was used to develop a model for both of these datasets. Model comparison for the enoxaparin dataset was performed by using the posterior distribution of the log-likelihood and a posterior predictive check. The use of WinBUGS supported the same structural models tried in NONMEM. For the gentamicin dataset a one-compartment model with intravenous infusion was developed, and the population parameters including the full between-subject variance-covariance matrix were available. Analysis of the enoxaparin dataset supported a two compartment model as superior to the one-compartment model, based on the posterior predictive check. Again, the full between-subject variance-covariance matrix parameters were available. Fully Bayesian approaches using MCMC methods, via WinBUGS, can offer added value for analysis of population pharmacokinetic data.

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Measurement of protein-polymer second virial coefficients (B-AP) by sedimentation equilibrium studies of carbonic anhydrase and cytochrome c in the presence of dextrans (T10-T80) has revealed an inverse dependence of B-AP upon dextran molecular mass that conforms well with the behaviour predicted for the excluded-volume interaction between a spherical protein solute A and a random-flight representation of the polymeric cosolute P. That model of the protein-polymer interaction is also shown to provide a reasonable description of published gel chromatographic and equilibrium dialysis data on the effect of polymer molecular mass on BAP for human serum albumin in the presence of polyethylene glycols, a contrary finding from analysis of albumin solubility measurements being rejected on theoretical grounds. Inverse dependence upon polymer chainlength is also the predicted excluded-volume effect on the strength of several types of macromolecular equilibria-protein isomerization, protein dimerization, and 1 : 1 complex formation between dissimilar protein reactants. It is therefore concluded that published experimental observations of the reverse dependence, preferential reaction enhancement within DNA replication complexes by larger polyethylene glycols, must reflect the consequences of cosolute chemical interactions that outweigh those of thermodynamic nonideality arising from excluded-volume effects. (c) 2005 Elsevier B.V. All rights reserved.

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Many recombinant proteins are often over-expressed in host cells, such as Escherichia coli, and are found as insoluble and inactive protein aggregates known as inclusion bodies (IBs). Recently, a novel process for IB extraction and solubilisation, based on chemical extraction, has been reported. While this method has the potential to radically intensify traditional IB processing, the process economics of the new technique have yet to be reported. This study focuses on the evaluation of process economics for several IB processing schemes based on chemical extraction and/or traditional techniques. Simulations and economic analysis were conducted at various processing conditions using granulocyte macrophage-colony stimulating factor, expressed as IBs in E. coli, as a model protein. In most cases, IB processing schemes based on chemical extraction having a shorter downstream cascade demonstrated a competitive economic edge over the conventional route, validating the new process as an economically more viable alternative for IB processing.

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Objective To compare mortality burden estimates based on direct measurement of levels and causes in communities with indirect estimates based on combining health facility cause-specific mortality structures with community measurement of mortality levels. Methods. Data from sentinel vital registration (SVR) with verbal autopsy (VA) were used to determine the cause-specific mortality burden at the community level in two areas of the United Republic of Tanzania. Proportional cause-specific mortality structures from health facilities were applied to counts of deaths obtained by SVR to produce modelled estimates. The burden was expressed in years of life lost. Findings. A total of 2884 deaths were recorded from health facilities and 2167 recorded from SVR/VAs. In the perinatal and neonatal age group cause-specific mortality rates were dominated by perinatal conditions and stillbirths in both the community and the facility data. The modelled estimates for chronic causes were very similar to those from SVR/VA. Acute febrile illnesses were coded more specifically in the facility data than in the VA. Injuries were more prevalent in the SVR/VA data than in that from the facilities. Conclusion. In this setting, improved International classification of diseases and health related problems, tenth revision (ICD-10) coding practices and applying facility-based cause structures to counts of deaths from communities, derived from SVR, appears to produce reasonable estimates of the cause-specific mortality burden in those aged 5 years and older determined directly from VA. For the perinatal and neonatal age group, VA appears to be required. Use of this approach in a nationally representative sample of facilities may produce reliable national estimates of the cause-specific mortality burden for leading causes of death in adults.

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The effects of process variables on the quality of high-pressure die cast components was determined with the aid of in-cavity pressure sensors. In particular, the effects of set intensification pressure, delay time, and casting velocity have been investigated. The in-cavity pressure sensor has been used to determine how conditions within the die-cavity are related to the process parameters regulated by the die casting machine, and in turn the effect of variations in these parameters on the integrity of the final part. Porosity was found to decrease with increasing intensification pressure and increase with increasing casting velocity. The delay time before the application of the intensification pressure was not observed to have a significant effect on porosity levels. (c) 2006 Elsevier B.V. All rights reserved.

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Land-surface processes include a broad class of models that operate at a landscape scale. Current modelling approaches tend to be specialised towards one type of process, yet it is the interaction of processes that is increasing seen as important to obtain a more integrated approach to land management. This paper presents a technique and a tool that may be applied generically to landscape processes. The technique tracks moving interfaces across landscapes for processes such as water flow, biochemical diffusion, and plant dispersal. Its theoretical development applies a Lagrangian approach to motion over a Eulerian grid space by tracking quantities across a landscape as an evolving front. An algorithm for this technique, called level set method, is implemented in a geographical information system (GIS). It fits with a field data model in GIS and is implemented as operators in map algebra. The paper describes an implementation of the level set methods in a map algebra programming language, called MapScript, and gives example program scripts for applications in ecology and hydrology.