123 research outputs found
Análise do impacto da implantação de sistemas ERP nas características organizacionais das empresas de construção civil
Uma das causas do insucesso do ERP nas empresas de construção civil é o fato da implantação desse sistema ser uma grande mudança organizacional. O objetivo desta pesquisa é identificar como a implementação do sistema ERP impacta na organização e nos processos gerencias das empresas de construção civil. Foi realizada uma survey em uma amostra de empresas construtoras brasileiras. Os dados foram coletados por meio de um questionário encaminhado por email a dois grupos de empresas: com e sem ERP implantado. A partir da análise estatística discriminante foi possível identificar as variáveis relacionadas ao nível de desenvolvimento dos processos de gestão e as características organizacionais que mais distinguem os dois grupos de empresas. Os resultados revelaram que a implantação do ERP impacta nas variáveis da maturidade organizacional nos seguintes aspectos: visão estratégica, relacionamento com cliente, gerenciamento de recursos humanos, gestão financeira e de TI
Maspin enhances cisplatin chemosensitivity in bladder cancer T24 and 5637 cells and correlates with prognosis of muscle-invasive bladder cancer patients receiving cisplatin based neoadjuvant chemotherapy
Analysis and Prediction of the Thermal Performance of Piezoelectrically Actuated Fans
An experimentally validated numerical model is developed to analyze the operation of a piezoelectrically actuated cantilever vibrating close to a heated surface. The vibrating cantilever acts as a fan and provides localized cooling. The numerical results for the flow field and heat transfer show satisfactory agreement with experiments. The numerical model is used to develop fan curves for the piezoelectric fans, using a methodology similar to that used in constructing pump or fan curves for conventional fans. A simplified model based on stagnation region heat transfer in impingement flows is also proposed to estimate the heat transfer from a piezoelectric fan. The velocities obtained from the piezoelectric fan curves generated are used in this impingement heat transfer model, and the predictions are found to agree with measured stagnation zone Nusselt numbers with an average deviation of 17%
Characterization and Optimization of the Thermal Performance of Miniature Piezoelectric Fans
Piezoelectric fans have emerged as a viable cooling technology for the thermal management of electronic devices, owing to their low- power consumption, minimal noise emission, and small and configurable dimensions. Piezoelectric fans are investigated for application in the cooling of low-power electronics. Different experimental configurations are considered, and the effect of varying the fan amplitude, the distance between the fan and the heat source, the fan length, its frequency offset from resonance, and the fan offset from the center of the heat source are studied to assess the cooling potential of the fans. A design of experiments (DOE) analysis revealed the fan frequency offset from resonance and the fan amplitude as the critical parameters. Transfer functions are obtained from the DOE analysis for the implementation of these fans in electronics cooling. For the best case, an enhancement in convective heat transfer coefficient exceeding 375% relative to natural convection was observed, resulting in a temperature drop at the heat source of more than 36.4 °C. A computational model for the flow field and heat transfer induced by the piezoelectric fan is also developed. Effects of the flow on convection heat transfer for different fan-to-heat source distances and boundary conditions are analyzed. Transition between distinct convection patterns is observed with changes in the parameters. The computational results are validated against experimental measurements, with good agreement
Experimental Investigation of the Thermal Performance of Piezoelectric Fans
Piezoelectric fans are investigated as a cooling technology for the thermal management of electronic devices. Flow visualization experiments are conducted to better understand the physics of fan operation. Prototypes of the fans are built and tested to assess their feasibility and cooling performance and determine optimal locations for the fans. An enclosure the size of a cellular phone and a commercially available laptop computer are used to demonstrate the cooling feasibility of the fans. Piezoelectric fans are found to offer significant localized cooling, exceeding enhancements in convective heat transfer coefficients of 100%, while exhibiting low power consumption, minimal noise, and small dimensions. Performance metrics for piezoelectric fans should be based on heat transfer characteristics, such as the percent increase in the heat transfer coefficient of the system. Optimization techniques that maximize the electromechanical coupling factor (EMCF) can be used to design efficient fans
Unusual electrocardiographic changes with propranolol and diltiazem overdosage: a case report.
PubMedID: 12845395The therapeutic efficacy and safety of beta-adrenoreceptor-blocking drugs has been well established in patients with angina pectoris, cardiac arrhythmias, and hypertension and reducing the risk of mortality and nonfatal reinfarction on survival of acute myocardial infarction. The calcium antagonists are used for the treatment of patients with angina pectoris, long-term systemic hypertension, and the management of hypertensive emergencies and also for a multitude of other cardiovascular and noncardiovascular conditions. Because adverse cardiovascular effects can occur, however, patients being considered for combination treatment with propranolol and diltiazem must be selected carefully and observed closely. In this article, we present a suicidal case of drug overdose with propranolol and diltiazem with unusual electrocardiographic changes
Snakebite during pregnancy
PubMedID: 16119247Little is known about snakebites during pregnancy and only a few cases have been reported in the literature. The fact that venomous snakebites during pregnancy result in high fetal wastage and may cause maternal mortality makes this an important, albeit, uncommonly encountered entity in emergency medicine. In this paper, we report on the successful treatment of three cases of snakebite in pregnancy. © 2005 Edward Arnold (Publishers) Ltd
Synthesis of ferrocenyl quinones
A squarate-based synthesis of ferrocenyl quinones is described. Thermolysis of ferrocenyl-substituted cyclobutenones, prepared from ferrocenyl cyclobutenediones and alkenyllithiums, affords hydroquinones, which furnish, upon oxidation, ferrocenyl quinones. Ferrocenyl cyclobutenediones have been prepared from known cyclo butenediones by nucleophilic addition of ferrocenyllithium followed by hydrolysis, Pd/Cu-cocatalyzed cross-coupling with (tri-n-butylstannyl)ferrocene or Friedel-Crafts alkylation with ferrocene
Ostracoda assemblage and the environmental characteristics of the Eocene Succession of the Central Sakarya Region
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