Thermoeconomic Simulation of Cascaded and Integrated Vapor Compression-Absorption Refrigeration Systems

The present work is composed by a comparative thermoeconomic analysisbetween two refrigeration systems: Vapor Compression CascadeRefrigeration System (VCCRS) and Integrated Refrigeration System byAbsorption and Vapor Compression (VCACRS). The thermoeconomicanalysis compares the systems under energy, exergy, economic andenvironmental aspects. The development of mathematical models for each ofthe systems is performed through the EES (Engineering Equation Solver)program. The optimized functions are exergy destruction and total cost rate(sum of cost rates of investment, operation, maintenance and enviromental)by minimizing these functions. The optimization method used is theweighted sum of the objectives, this can be achieved by assigning differentweights for each goal, then a new function that represents the linearrelationship between all the objectives is found. In present case the twoobjective functions are exergy destruction and total cost rate. Inmultiobjective optimization, the process of choosing among optimizedsolutions involves the definition of an equilibrium point, also called theideal point. In order to achieve a real solution of the minimum values ofthe described functions simultaneously one must determine which is thesmallest distance from the ideal point to the curve that defines theoptimized solutions. In the study the economical advantage of VCCRS inrelation to VCACRS was demonstrated. VCACRS has a cost 10.26% lowerthan VCCRS while VCCRS has a better exergetic efficiency, with itsdestruction of exergy 38.46% lower than VCACRS

Changes in the soil structure and organic matter dynamics under different plant covers.

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Eficiência da produção agrícola de cana-de-açúcar no Estado de São Paulo entre as safras 1990/1991 a 2005/2006.

O objetivo do presente trabalho foi mapear a eficiência produtiva ao longo de 16 safras agrícolas, analisando a importância relativa do clima e do solo e inferindo sobre os aspectos socioeconômicos e conjunturais que interferem na sua composição. Admitiu-se que a energia disponível pode ser dada pela produtividade atingível estimada por modelos de simulação baseados em variáveis ambientais, enquanto que a produtividade observada representaria a energia efetivamente utilizada no processo. Os elementos climáticos explicaram 43% da variabilidade da eficiência da produção agrícola de cana-de-açúcar, na seguinte ordem de importância: radiação solar, deficiência hídrica, temperatura máxima, precipitação e temperatura mínima. Observou-se que o solo explicou 15% da variabilidade da eficiência, na média de todas as safras. Analisando a variação temporal dessa correlação, notou-se uma alteração no padrão de correlação a partir da safra 2001/2002. Em média, 42% da variabilidade da eficiência da produção de cana-de-açúcar no Estado de São Paulo foram explicadas por outros fatores, além do clima e do solo.CBA 2009

Etiological diagnosis, prognostic significance and role of electrophysiological study in patients with Brugada ECG and syncope.

BACKGROUND: Syncope is considered a risk factor for life-threatening arrhythmias in Brugada patients. Distinguishing a benign syncope from one due to ventricular arrhythmias is often difficult, unless an ECG is recorded during the episode. Aim of the study was to analyze the characteristics of syncopal episodes in a large population of Brugada patients and evaluate the role of electrophysiological study (EPS) and the prognosis in the different subgroups. METHODS AND RESULTS: One hundred ninety-five Brugada patients with history of syncope were considered. Syncope were classified as neurally mediated (group 1, 61%) or unexplained (group 2, 39%) on the basis of personal and family history, clinical features, triggers, situations, associated signs, concomitant therapy. Most patients underwent EPS; they received ICD or implantable loop-recorder on the basis of the result of investigations and physician's judgment. At 62±45months of mean follow-up, group 1 showed a significantly lower incidence of arrhythmic events (2%) as compared to group 2 (9%, p<0.001). Group 2 patients with positive EPS showed the highest risk of arrhythmic events (27%). No ventricular events occurred in subjects with negative EPS. CONCLUSION: Etiological definition of syncope in Brugada patients is important, as it allows identifying two groups with different outcome. Patients with unexplained syncope and ventricular fibrillation induced at EPS have the highest risk of arrhythmic events. Patients presenting with neurally mediated syncope showed a prognosis similar to that of the asymptomatic and the role of EPS in this group is unproven

Ocorrência da murcha de Sclerotium no feijão caupi no estado do Pará.

Edição dos resumos do 44º Congresso Brasileiro de Fitopatologia, 2011, Bento Gonçalves. Resumo 1173

Longevidade de Thielaviopsis paradoxa, agente causal da resinose do coqueiro em Rhynchophorus palmarum.

O objetivo do presente trabalho foi discutir a longevidade do fungo Thielaviopsis paradoxa, agente causal da resinose do estirpe do coqueiro, em seu vetor, o besouro Rhynchophorus palamarum. Foi realizado um estudo microbiológico da superfície e do tubo digestivo dos insetos adultos que foram coletados em duas regiões do Estado de Sergipe: uma com plantações apresentando sintomas da resinose e outra sem focos da doença. Os insetos foram divididos em dois lotes de 40 insetos (20 machos e 20 fêmeas) para cada região. Os besouros foram esfregados um a um em placa de petri contendo meio BDA, um besouro por placa, desinfectados externamente com hipoclorito sódio e o tubo digestivo de cada um dos insetos esfregados foi retirado e dividido em suas três partes principais: estomodeu, mesêntero e proctodeu. Estas partes foram inseridas em meio de cultura BDA e mantidas em BOD a 25 ° C por 5 dias. Foi verificada a patogenicidade dos isolados de T. paradoxa em coqueiros utilizando três métodos de inoculação. Os isolamentos realizados a partir da parte externa e no tubo digestivo dos insetos do município de Neópolis resultaram em 96,3% e 77,5% de crescimento micelial de T. paradoxa respectivamente e foi comprovada a patogenicidade dos isolados em plantas de coqueiro. Ficou comprovado a perda de longevidade do patógeno dentro do vetor após 7 dias, na ausência de nova fonte de infecção

The incidence of cancer and potential role of sirolimus immunosuppression conversion on mortality among a single-center renal transplantation cohort of 1,816 patients

INTRODUCTION: The chronic use of immunosuppressive drugs in renal transplant recipients increases the risk of developing de novo malignancies. Herein we analyze the incidence of de novo tumors and the potential role of sirolimus to improve cancer-specific survival among a cohort at a single center. METHODS: This retrospective analysis of our 1,816 patients allografted between January 1983 and December 2009 sought subjects who developed de novo tumors. Epidemiological and clinical data were examined using Mann-Whitney and Pearson's chi-square or Fisher exact tests for statistical comparisons of continuous and categorical variables, respectively. Kaplan-Meier survival curves were used to determine cancer-specific survival according to type of neoplasia and immunosuppressive regimen, namely, conversion to sirolimus. RESULTS: One hundred patients (5.5%) were diagnosed with a de novo malignancy. The 110 different cancers were diagnosed at a median interval of 73 months after kidney transplantation. The overall cancer-specific survivals at 1 and 5 years after cancer diagnosis were 87.0% and 76.9%, respectively. The 15 patients converted to sirolimus showed no difference in survival. CONCLUSION: The observed frequencies of cancer in our center are consistent with the literature. Among our cohort, sirolimus did not significantly impact survival among subjects who had de novo malignancies