Abstract: For geographic regions where significant power demand and highest electricity prices occur during the warm months, a gas turbine inlet air cooling technique is a useful option for increasing output. Inlet air cooling increases the power output by taking advantage of the gas turbine's feature of higher mass flow rate, due the compressor inlet temperature decays. Industrial gas turbines that opera te at constant speed are constant-volume-flow combustion machines. As the specific volume of air is directly proportional to the temperature, the increases of the air density results in a higher air mass flow rate, once the volumetric rate is constant. Consequently, the gas turbine power output enhances. Different methods are available for reducing compressor intake air temperature. There are I two basic systems currently available for inlet cooling. The first and most cost-effective system is the evaporative cooling. Evaporative coolers make use of the evaporation of water to reduce the gas turbine inlet air temperature. The second system employs two ways to cool the inlet air: mechanical compression and absorption. In this method, the cooling medium flows through a heat exchanger located in the inlet duct to remove heat from the inlet air. In the present study, a thermodynamic analysis of gas turbine performance is carried out to calculate heat rate, power output and thermal efficiency at different inlet air temperature and relative humidity conditions. The results obtained I with this model are compared with the values of the condition without cooling herein named of Base-Case. Then, the three cooling techniques are computationally implemented and solved for different inlet conditions (inlet temperature and relative humidity). In addition, the gas turbine was tested under different cooling methods for two Brazilian sites, and comparison between chiller systems (mechanical and absorption) showed that the absorption chiller provides the highest increment in annual energy generation with lower unit energy costs. On the other hand, evaporative cooler offered the lowest unit energy cost but associated with a limited cooling potential.

OBJETIVOS: Analisar as frequências de hospitalização e de atendimentos em serviços de urgência ocorridas em crianças e adolescentes antes e após o ingresso em programa de asma no Brasil. MÉTODOS: Prontuários de 608 pacientes menores de 15 anos e com asma foram avaliados retrospectivamente. As frequências de hospitalização por asma e de atendimentos em serviços de urgência para episódios agudos de broncoespasmo foram avaliadas nos períodos anterior e posterior à admissão no programa que disponibiliza medicamentos, preconiza abordagem integral do paciente e manejo profilático de acordo com a Global Initiative for Asthma (GINA). O período de observação antes do programa (AP) teve a duração de 12 meses enquanto o depois do programa (DP) variou de 12 a 36 meses. RESULTADOS: No período AP, ocorreram 895 hospitalizações e 5.375 atendimentos em serviços de urgência, e no período DP, ocorreram 180 hospitalizações e 713 atendimentos na urgência. O teste t de Student para amostras pareadas e o modelo de regressão para observações dependentes identificaram efeito significativo do programa em relação às variáveis estudadas (p = 0,000). CONCLUSÕES: A adoção das recomendações do GINA levou à redução significativa nas frequências de hospitalização e atendimentos na urgência em crianças e adolescentes com asma.

OBJECTIVES: To assess the frequency of hospitalizations and emergency department visits of children and adolescents before and after the enrolment in an asthma program. METHODS: Medical records of 608 asthmatics younger than 15 years were assessed retrospectively. The frequency of hospitalizations and emergency department visits caused by exacerbations were evaluated before and after enrolment in an asthma program. Patients were treated with medications and a wide prophylactic management program based on the Global Initiative for Asthma (GINA). The before asthma program (BAP) period included 12 months before enrollment, whereas the after asthma program (AAP) period ranged from 12 to 56 months after enrollment. RESULTS: In the BAP period, there were 895 hospitalizations and 5,375 emergency department visits, whereas in the AAP period, there were 180 and 713, respectively. This decrease was significant in all statistical analyses (p = 0.000). CONCLUSIONS: Compliance with the GINA recommendations led to a significant decrease in the frequency of hospitalizations and emergency department visits in children and adolescents with asthma.

OBJETIVOS: Avaliar os valores de cortisol basal em asmáticos persistentes em uso de propionato de fluticasona inalatório na dose de 200 ou 300 mcg/dia. MÉTODOS: O diagnóstico e a classificação da gravidade da asma basearam-se nas recomendações do Global Initiative for Asthma. Pacientes menores de 11 anos receberam fluticasona na dose de 200 mcg/dia, e aqueles com mais de 11 anos receberam 300 mcg/dia. Após 10 semanas de tratamento, a dosagem do cortisol foi realizada para avaliação da função adrenal. RESULTADOS: Foram avaliados 41 pacientes (65,9% do sexo masculino) entre 6 e 18 anos. Não houve diferença significativa entre as médias de cortisol basal nos pacientes que receberam 200 mcg/dia de propionato de fluticasona (n = 13) e naqueles que receberam 300 mcg/dia (n = 28). CONCLUSÕES: Os achados mostram que doses baixas a moderadas de propionato de fluticasona não causam supressão adrenal.

OBJECTIVES: To evaluate basal plasma cortisol in persistent asthmatics on inhaled fluticasone propionate 200 mcg/day and 300 mcg/day. METHODS: Asthma diagnosis and classification was based on Global Initiative for Asthma recommendations. Patients aged 11 years old or less received fluticasone propionate 200 mcg/day and those older than 11 years received 300 mcg/day. After 10 weeks of treatment, plasma cortisol levels were monitored to evaluate the hypothalamic-pituitary-adrenal axis. RESULTS: Forty-one patients (65.9% males) aged 6 to 18 years old were evaluated. No statistical differences were found between plasma cortisol levels in patients who received 200 mcg/day (n = 13) and those who received 300 mcg/day (n = 28). CONCLUSIONS: Our results show that low and moderate doses of fluticasone propionate do not cause adrenal suppression.

This work studies the forced convection problem in internal flow between concentric annular ducts, with radial fins at the internal tube surface. The finned surface heat transfer is analyzed by two different approaches. In the first one, it is assumed one-dimensional heat conduction along the internal tube wall and fins, with the convection heat transfer coefficient being a known parameter, determined by an uncoupled solution. In the other way, named conjugated approach, the mathematical model (continuity, momentum, energy and K-epsilon equations) applied to tube annuli problem was numerically solved using finite element technique in a coupled formulation. At first time, a comparison was made between results obtained for the conjugated problem and experimental data, showing good agreement. Then, the temperature profiles under these two approaches were compared to each other to analyze the validity of the one-dimensional classical formulation that has been utilized in the heat exchanger design.