892 resultados para Dispersed production system


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This article describes an application of computers to a consumer-based production engineering environment. Particular consideration is given to the utilisation of low-cost computer systems for the visual inspection of components on a production line in real time. The process of installation is discussed, from identifying the need for artificial vision and justifying the cost, through to choosing a particular system and designing the physical and program structure.

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An in vitro study was conducted to investigate the effect of tannins on the extent and rate of gas and methane production, using an automated pressure evaluation system (APES). In this study three condensed tannins (CT; quebracho, grape seed and green tea tannins) and four hydrolysable tannins (HT; tara, valonea, myrabolan and chestnut tannins) were evaluated, with lucerne as a control substrate. CT and HT were characterised by matrix assisted laser desorption ionisation-time of flight mass spectrometry (MALDI-TOF-MS). Tannins were added to the substrate at an effective concentration of 100 g/kg either with or without polyethylene glycol (PEG6000), and incubated for 72 h in pooled, buffered rumen liquid from four lactating dairy cows. After inoculation, fermentation bottles were immediately connected to the APES to measure total cumulative gas production (GP). During the incubation, 11 gas samples were collected from each bottle at 0, 1, 4, 7, 11, 15, 23, 30, 46, 52 and 72 h of incubation and analysed for methane. A modified Michaelis-Menten model was fitted to the methane concentration patterns and model estimates were used to calculate the total cumulative methane production (GPCH4). GP and GPCH4 curves were fitted using a modified monophasic Michaelis-Menten model. Addition of quebracho reduced GP (P=0.002), whilst the other tannins did not affect GP. Addition of PEG increased GP for quebracho (P=0.003), valonea (P=0.058) and grape seed tannins (P=0.071), suggesting that these tannins either inhibited or tended to inhibit fermentation. Addition of quebracho and grape seed tannins also reduced (P≤0.012) the maximum rate of gas production, indicating that microbial activity was affected. Quebracho, valonea, myrabolan and grape seed decreased (P≤0.003) GPCH4 and the maximum rate (0.001≤ P≤ 0.102) of CH4 production. Addition of chestnut, green tea and tara tannins did not affect total gas nor methane production. Valonea and myrabolan tannins have most promise for reducing methane production as they had only a minor impact on gas production.

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In this paper, we study a model economy that examines the optimal intraday rate. In Freeman’s (1996) paper, he shows that the efficient allocation can be implemented by adopting a policy in which the intraday rate is zero. We modify the production set and show that such a model economy can account for the non-uniform distribution of settlements within a day. In addition, by modifying both the consumption set and the production set, we show that the central bank may be able to implement the planner’s allocation with a positive intraday interest rate.

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We present an outlook on the climate system thermodynamics. First, we construct an equivalent Carnot engine with efficiency and frame the Lorenz energy cycle in a macroscale thermodynamic context. Then, by exploiting the second law, we prove that the lower bound to the entropy production is times the integrated absolute value of the internal entropy fluctuations. An exergetic interpretation is also proposed. Finally, the controversial maximum entropy production principle is reinterpreted as requiring the joint optimization of heat transport and mechanical work production. These results provide tools for climate change analysis and for climate models’ validation.

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We present the multiplicity and pseudorapidity distributions of photons produced in Au + Au and Cu + Cu collisions at root(s)NN = 62.4 and 200 GeV. The photons are measured in the region -3.7 < eta < -2.3 using the photon Multiplicity detector in the STAR experiment at RHIC. The number of photons produced per average number of participating nucleon pairs increases with the beam energy and is independent of (lie collision centrality. For collisions with similar average numbers of participating nucleons the photon multiplicities are observed to be similar for An + Au and Cu + Cu collisions at a given beam energy. The ratios of the number of charged particles to photons in the measured pseudorapidity range are found to be 1.4 +/- 0.1 and 1.2 +/- 0.1 for root(s)NN = 62.4 and 200 GeV, respectively. The energy dependence of this ratio could reflect varying contributions from baryons to charged particles, while mesons are the dominant contributors to photon production in the given kinematic region. The photon pseudorapidity distributions normalized by average number of participating nucleon pairs, when plotted as a function of eta-Y(beam), are found to follow a longitudinal scaling independent of centrality and colliding ion species at both beam energies. (C) 2009 Elsevier B.V. All rights reserved.

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We study the beam-energy and system-size dependence of phi meson production (using the hadronic decay mode phi -> K(+) K(-)) by comparing the new results from Cu + Cu collisions and previously reported Au + Au collisions at root s(NN) = 62.4 and 200 GeV measured in the STAR experiment at RHIC. Data presented in this Letter are from mid-rapidity (vertical bar y vertical bar < 0.5) for 0.4 < p(T) < 5 GeV/c. At a given beam energy, the transverse momentum distributions for phi mesons are observed to be similar in yield and shape for Cu + Cu and Au + Au colliding systems with similar average numbers of participating nucleons. The phi meson yields in nucleus-nucleus collisions, normalized by the average number of participating nucleons, are found to be enhanced relative to those from p + p collisions. The enhancement for phi mesons lies between strange hadrons having net strangeness = 1 (K(-) and <(A)over bar>) and net strangeness = 2 (Xi). The enhancement for phi mesons is observed to be higher at root s(NN) = 200 GeV compared to 62.4 GeV. These observations for the produced phi(s (s) over bar) mesons clearly suggest that, at these collision energies, the source of enhancement of strange hadrons is related to the formation of a dense partonic medium in high energy nucleus-nucleus collisions and cannot be alone due to canonical suppression of their production in smaller systems. (C) 2009 Elsevier B.V. All rights reserved.

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This paper reports the production of bismuth germanate ceramic scintillator (Bi4Ge3O12) by combustion synthesis (SHS) method, focusing on the influence of the synthesis parameters on the crystalline phases and agglomeration of the nanoparticles. The synthesis and sintering conditions were investigated through thermal analysis, X-ray diffraction as function of temperature, dilatometry and scanning electron microscopy. Well-dispersed Bi4Ge3O12 powder was accomplished by the combustion of the initial solution at pH 9, followed by low temperature calcination and milling. Sintered ceramics presented relative density of 98% and single crystalline Bi4Ge3O12 phase. The luminescent properties of the ceramics were investigated by photo- and radio- luminescence measurements and reproduced the typical Bi4Ge3O12 single-crystal spectra when excited with UV, beta and X-rays. The sintered ceramics presented light output of 4.4 x 10(3) photons/McV. (c) 2008 Published by Elsevier Ltd.

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Methylglyoxal is an a-oxoaldehyde putatively produced in excess from triose phosphates, aminoacetone, and acetone in some disorders, particularly in diabetes. Here, we investigate the nucleophilic addition of ONOO(-), known as a potent oxidant and nucleophile, to methylglyoxal, yielding an acetyl radical intermediate and ultimately formate and acetate ions. The rate of ONOO(-) decay in the presence of methylglyoxal [k(2,app) = (1.0 +/- 0.1) x 10(3) M(-1) s(-1); k(2) approximate to 1.0 x 10(5) M(-1) s(-1)] at pH 7.2 and 25 degrees C was found to be faster than that reported with monocarbonyl substrates (k(2) < 10(3) M(-1) diacetyl (k(2) = 1.0 x 10(4) M(-1) s(-1)), or CO(2) (k(2) = 3-6 x 10(4) M(-1) s(-1)). The pH profile of the methylglyoxal peroxynitrite reaction describes an ascendant curve with an inflection around pH 7.2, which roughly coincides with the pK(a) values of both ONOOH and H(2)PO(4)(-) ion. Electron paramagnetic resonance spin trapping experiments with 2-methyl-2-nitrosopropane revealed concentration-dependent formation of an adduct that can be attributed to 2-methyl-2-nitrosopropane-CH(3)CO(center dot) (a(N) = 0.83 mT). Spin trapping with 3,5-dibromo-4-nitrosobenzene sulfonate gave a signal that could be assigned to a methyl radical adduct [a(N) = 1.41 mT; a(H) = 1.35 mT; a(H(m)) = 0.08 mT]. The 2-methyl-2-nitrosopropane-CH(3)CO(center dot) adduct could also be observed by replacement of ONOO(-) with H(2)O(2), although at much lower yields. Acetyl radicals could be also trapped by added L-lysine as indicated by the presence of W-acetyl-L-lysine in the spent reaction mixture. This raises the hypothesis that ONOO(-)/H(2)O(2) in the presence of methylglyoxal is endowed with the potential to acetylate proteins in post-translational processes.

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This master thesis presents a new technological combination of two environmentally friendly sources of energy in order to provide DHW, and space heating. Solar energy is used for space heating, and DHW production using PV modules which supply direct current directly to electrical heating elements inside a water storage tank. On the other hand a GSHP system as another source of renewable energy provides heat in the water storage tank of the system in order to provide DHW and space heating. These two sources of renewable energy have been combined in this case-study in order to obtain a more efficient system, which will reduce the amount of electricity consumed by the GSHP system.The key aim of this study is to make simulations, and calculations of the amount ofelectrical energy that can be expected to be produced by a certain amount of PV modules that are already assembled on a house in Vantaa, southern Finland. This energy is then intended to be used as a complement to produce hot water in the heating system of the house beside the original GSHP system. Thus the amount of electrical energy purchased from the grid should be reduced and the compressor in the GSHP would need fewer starts which would reduce the heating cost of the GSHP system for space heating and providing hot water.The produced energy by the PV arrays in three different circuits will be charged directly to three electrical heating elements in the water storage tank of the existing system to satisfy the demand of the heating elements. The excess energy can be used to heat the water in the water storage tank to some extent which leads to a reduction of electricity consumption by the different components of the GSHP system.To increase the efficiency of the existing hybrid system, optimization of different PV configurations have been accomplished, and the results are compared. Optimization of the arrays in southern and western walls shows a DC power increase of 298 kWh/year compared with the existing PV configurations. Comparing the results from the optimization of the arrays on the western roof if the intention is to feed AC power to the components of the GSHP system shows a yearly AC power production of 1,646 kWh.This is with the consideration of no overproduction by the PV modules during the summer months. This means the optimized PV systems will be able to cover a larger part of summer demand compared with the existing system.

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The effect of finishing extensive farming period, to reduce fat content and manipulate the fatty acid profile of fish muscle, was evaluated in rainbow trout. Fish were stocked in an artificial lake, in which fish were fed only on naturally available nutrients with no supply of artificial feed, for different lengths of time from 0 to 120 days. No weight loss was noted during the whole finishing period while total length increased from 228±7 to 269±3 mm and the condition factor decreased from 1.41±0.04 to 0.89±0.02. The total fat content of the fillets decreased considerably from 4.7±0.6% at the beginning to 2.4±0.4% and 0.7±0.2% after 45 and 120 days respectively. Fillet fatty acid composition was affected by the time of stocking in the extensive farm. In contrast to the reduction in C18:1n-9, C18:2n-6, total monounsaturated fatty acid and total n-6 percent values, an increase in the C20:5n-3, C22:6n-3, total polyunsaturated fatty acid and total n-3 percent values was observed. It was shown that while other finishing strategies for salmonids have some disadvantages, the extensive culture system seems to be a potentially useful tool for increasing the general quality of the end product.

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The study examined the implication of the renin-angiotensin system (RAS) in regulation of splanchnic blood flow and glucose production in exercising humans. Subjects cycled for 40 min at 50% maximal O2 consumption (VO2 max) followed by 30 min at 70% VO2 max either with [angiotensin-converting enzyme (ACE) blockade] or without (control) administration of the ACE inhibitor enalapril (10 mg iv). Splanchnic blood flow was estimated by indocyanine green, and splanchnic substrate exchange was determined by the arteriohepatic venous difference. Exercise led to an ~20-fold increase (P < 0.001) in ANG II levels in the control group (5.4 ± 1.0 to 102.0 ± 25.1 pg/ml), whereas this response was blunted during ACE blockade (8.1 ± 1.2 to 13.2 ± 2.4 pg/ml) and in response to an orthostatic challenge performed postexercise. Apart from lactate and cortisol, which were higher in the ACE-blockade group vs. the control group, hormones, metabolites, VO2, and RER followed the same pattern of changes in ACE-blockade and control groups during exercise. Splanchnic blood flow (at rest: 1.67 ± 0.12, ACE blockade; 1.59 ± 0.18 l/min, control) decreased during moderate exercise (0.78 ± 0.07, ACE blockade; 0.74 ± 0.14 l/min, control), whereas splanchnic glucose production (at rest: 0.50 ± 0.06, ACE blockade; 0.68 ± 0.10 mmol/min, control) increased during moderate exercise (1.97 ± 0.29, ACE blockade; 1.91 ± 0.41 mmol/min, control). Refuting a major role of the RAS for these responses, no differences in the pattern of change of splanchnic blood flow and splanchnic glucose production were observed during ACE blockade compared with controls. This study demonstrates that the normal increase in ANG II levels observed during prolonged exercise in humans does not play a major role in the regulation of splanchnic blood flow and glucose production.

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A process for producing plate-like alumina particles with a high aspect ratio is described. Nano-sized particles of an aluminium precursor compound, optionally formed by milling, are mixed with a sufficient volume fraction of a diluent and heat treated to form substantially discrete plate-like alpha alumina particles dispersed in the diluent. A mineraliser may be added to lower the effective melting point of the system. Substantially discrete plate-like particles may be formed without agitation when the heat treatment is conducted below the melting point of the diluent.

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A process for producing plate-like alumina particles with a high aspect ratio is described. Nano-sized particles of an aluminium precursor compound, optionally formed by milling, are mixed with a sufficient volume fraction of a diluent and heat treated to form substantially discrete plate-like alpha alumina particles dispersed in the diluent. A mineraliser may be added to lower the effective melting point of the system. Substantially discrete plate-like particles may be formed without agitation when the heat treatment is conducted below the melting point of the diluent.

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There is growing interest in the application of citizen participation within all areas of public sector service development, where it is increasingly promoted as a significant strand of post-neoliberal policy concerned with re-imagining citizenship and more participatory forms of citizen/consumer engagement. The application of such a perspective within health services, via co-production, has both beneficial, but also problematic implications for the organisation of such services, for professional practice and education. Given the disappointing results in increasing consumer involvement in health services via ‘choice’ and ‘voice’ participation strategies, the question of how the more challenging approach of co-production will fare needs to be addressed. The article discusses the possibilities and challenges of system-wide co-production for health. It identifies the discourse and practice contours of co-production, differentiating co-production from other health consumer-led approaches. Finally, it identifies issues critically related to the successful implementation of co-production where additional theorisation and research are required.

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This paper uses an output oriented Data Envelopment Analysis (DEA) measure of technical efficiency to assess the technical efficiencies of the Brazilian banking system. Four approaches to estimation are compared in order to assess the significance of factors affecting inefficiency. These are nonparametric Analysis of Covariance, maximum likelihood using a family of exponential distributions, maximum likelihood using a family of truncated normal distributions, and the normal Tobit model. The sole focus of the paper is on a combined measure of output and the data analyzed refers to the year 2001. The factors of interest in the analysis and likely to affect efficiency are bank nature (multiple and commercial), bank type (credit, business, bursary and retail), bank size (large, medium, small and micro), bank control (private and public), bank origin (domestic and foreign), and non-performing loans. The latter is a measure of bank risk. All quantitative variables, including non-performing loans, are measured on a per employee basis. The best fits to the data are provided by the exponential family and the nonparametric Analysis of Covariance. The significance of a factor however varies according to the model fit although it can be said that there is some agreements between the best models. A highly significant association in all models fitted is observed only for nonperforming loans. The nonparametric Analysis of Covariance is more consistent with the inefficiency median responses observed for the qualitative factors. The findings of the analysis reinforce the significant association of the level of bank inefficiency, measured by DEA residuals, with the risk of bank failure.