Portable MP3 player as low-cost data logger

Non-audio signals have been recorded in the flash ROM memory of a portable MP3 player, in WAV format file, to examine the possibility of using these cheap and small instruments as general-purpose portable data loggers. A 1200-Hz FM carrier modulated by the non-audio signal has replaced the microphone signal, while using the REC operating mode of the MP3 player, which triggers the voice recording function. The signal recovery was carried out by a PLL-based FM demodulator whose input is the FM signal captured in the coil leads of the MP3 player's earphone. Sinusoidal and electrocardiogram signals have been used in the system evaluation. Although the quality of low frequency signals needs improvement, overall the results indicate the viability of the proposal. Suggestions are made for improvements and extensions of the work.

Thermoeconomic analysis applied in cold water production system using biogas combustion

In this paper is proposed the use of biogas generated in the Wastewater Treatment Plant of a Dairy industry. The objective is to apply a thermoeconomic analysis to the supplementary cold water production of an absorption refrigeration system (NH3 + H2O) by the burning of such gas. The exergoeconomic analysis is carried out to allow a comparison between an absorption refrigeration system and of an equivalent compression refrigeration system that uses NH3 as work fluid. The proposed exergoeconomic model uses functional diagrams and allows one to obtain the exergetic incremental functions for each component individually and for the system as a whole. The model minimizes the exergetic manufacturing cost (EMC) which represents the cost of supplementary cold water production at 1degreesC (exergetic base) needed for this dairy's cold storage. As a conclusion, the absorption refrigeration system is better than compression refrigeration system, when the biogas cost is not considered. 2004 Elsevier Ltd. All rights reserved.

Thermoeconomic analysis of an evaporative desiccant air conditioning system

In this paper, a thermoeconomic analysis method based on the first and second law of thermodynamics and applied to an evaporative cooling system coupled to an adsorption dehumidifier, is presented. The main objective is the use of a method called exergetic manufacturing cost (EMC) applied to a system that operates in three different conditions to minimize the operation costs. Basic parameters are the RIP ratio (reactivation air/process air) and the reactivation air temperature. Results of this work show that the minimum reactivation temperature and the minimum RIP ratio corresponds to the smaller EMC. This result can be corroborated through an energetic analysis. It is noted that this case is also the one corresponding to smaller energy loss. (C) 2003 Elsevier B.V. Ltd. All rights reserved.

Ecological efficiency and thermoeconomic analysis of a cogeneration system at a hospital

This work aims with an approach for cogeneration plants evaluation based on thermoeconomic functional diagram analysis. The second law of thermodynamics is used to develop a methodology to analyse cogeneration systems, based on exergoeconomics evaluation. The thermoeconomic optimisation method developed is applied to allow a better configuration of the cogeneration plant associated to a university hospital. Also ecological efficiency is evaluated. The method was efficient and contributes for thermoeconomics modelling and analysis and can be applied to any sort of thermal system, especially those with combined heat and power in thermal parity. (C) 2012 Elsevier Ltd. All rights reserved.

Development of a methodology for cost determination of wastewater treatment based on functional diagram

This work describes a methodology developed for determination of costs associated to products generated in a small wastewater treatment station for sanitary wastewater from a university campus. This methodology begins with plant component units identification, relating their fluid and thermodynamics features for each point marked in its process diagram. Following, its functional diagram is developed and its formulation is elaborated, in exergetic base, describing all equations for these points, which are the constraints for exergetic production cost problem and are used in equations to determine the costs associated to products generated in SWTS. This methodology was applied to a hypothetical system based on SWTS former parts and presented consistent results when compared to expected values based on previous exergetic expertise. (C) 2008 Elsevier Ltd. All rights reserved.

Electricity, hot water and cold water production from biomass. Energetic and economical analysis of the compact system of cogeneration run with woodgas from a small downdraft gasifier

Wood gasification technologies to convert the biomass into fuel gas stand out. on the other hand, producing electrical energy from stationary engine is widely spread, and its application in rural communities where the electrical network doesn't exist is very required. The recovery of exhaust gases (engine) is a possibility that makes the system attractive when compared with the same components used to obtain individual heat such as electric power. This paper presents an energetic alternative to adapt a fixed bed gasifier with a compact cogeneration system in order to cover electrical and thermal demands in a rural area and showing an energy solution for small social communities using renewable fuels. Therefore, an energetic and economical analysis from a cogeneration system producing electric energy, hot and cold water, using wooden gas as fuel from a small-sized gasifier was calculated. The energy balance that includes the energy efficiency (electric generation as well as hot and cold water system; performance coefficient and the heat exchanger, among other items), was calculated. Considering the annual interest rates and the amortization periods, the costs of production of electrical energy, hot and cold water were calculated, taking into account the investment, the operation and the maintenance cost of the equipments. Crown Copyright (C) 2010 Published by Elsevier Ltd. All rights reserved.

Carbon fiber non-crimp multi-axial reinforcement and epoxy mono-component system composite: fatigue behavior

Fiber reinforced polymer composites have been widely applied in the aeronautical field. However, composite processing, which uses unlocked molds, should be avoided in view of the tight requirements and also due to possible environmental contamination. To produce high performance structural frames meeting aeronautical reproducibility and low cost criteria, the Brazilian industry has shown interest to investigate the resin transfer molding process (RTM) considering being a closed-mold pressure injection system which allows faster gel and cure times. Due to the fibrous composite anisotropic and non homogeneity characteristics, the fatigue behavior is a complex phenomenon quite different from to metals materials crucial to be investigated considering the aeronautical application. Fatigue sub-scale specimens of intermediate modulus carbon fiber non-crimp multi-axial reinforcement and epoxy mono-component system composite were produced according to the ASTM 3039 D. Axial fatigue tests were carried out according to ASTM D 3479. A sinusoidal load of 10 Hz frequency and load ratio R = 0.1. It was observed a high fatigue interval obtained for NCF/RTM6 composites. Weibull statistical analysis was applied to describe the failure probability of materials under cyclic loads and fractures pattern was observed by scanning electron microscopy. (C) 2010 Published by Elsevier Ltd.

Fault section estimation in electric power systems using an optimization immune algorithm

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Cost assessment of efficiency losses in hydroelectric plants

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Real-time multi-sensors measurement system with temperature effects compensation for impedance-based structural health monitoring

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Analysis of the performance of an extraction-condensation steam turbine on a cogeneration system of a Brazilian sugar-alcohol factory

In this work a detailed thermodynamic analysis for an extraction-condensation steam turbine capable to drive a 40 MVA electricity generator in a sugar-alcohol factory was carried out. The use of this turbine in the cogeneration system showed that its efficiency contributed to increase the power generation, although the condensation reduces the overall efficiency of the plant. Sensibility analyses were performed to evaluate the behavior of the overall energy efficiency of a plant with the extraction-condensation turbine in function of the boiler efficiency, the specific consumption of steam in the processes and the condensation rate in the turbine. It was observed that the plant efficiency is very sensible to the condensation rate variation and it increases when there is an increase in the demand of steam for processes.

Care cost for pregnant and parturient women with diabetes and mild hyperglycemia

OBJETIVO: Comparar custos de hospitalização e de atenção ambulatorial em gestantes/parturientes diabéticas e com hiperglicemia leve. MÉTODOS: Estudo observacional, prospectivo, quantitativo descritivo realizado em centro de diabete perinatal em Botucatu, SP, entre 2007 e 2008. Foram estimados os custos por absorção diretos e indiretos disponíveis na instituição e os custos específicos para a doença (medicamentos e exames). As 30 gestantes diabéticas tratadas com dieta foram acompanhadas em ambulatório e 20 tratadas com dieta mais insulina foram hospitalizadas. RESULTADOS: O custo da doença diabete (para a assistência pré-natal e parto) foi de US$ 3,311.84 para as gestantes hospitalizadas e de US$ 1,366.04 para as acompanhadas em ambulatório. CONCLUSÕES: Os custos diretos e indiretos e o custo total da assistência pré-natal foram mais elevados nas gestantes diabéticas hospitalizadas enquanto os custos da assistência ao parto e hospitalização para parto e puerpério foram semelhantes. Os custos da assistência pré-natal como no parto/puerpério foram superiores aos valores pagos pelo Sistema Único de Saúde.

Cost-benefit of hospitalization compared with outpatient care for pregnant women with pregestational and gestational diabetes or with mild hyperglycemia, in Brazil

CONTEXTO E OBJETIVO: Gestações complicadas pelo diabetes estão associadas com aumento de complicações maternas e neonatais. Os custos hospitalares aumentam de acordo com a assistência prestada. O objetivo foi calcular o custo-benefício e a taxa de rentabilidade social da hospitalização comparada ao atendimento ambulatorial em gestantes com diabetes ou com hiperglicemia leve. DESENHO do ESTUDO: Estudo prospectivo, observacional, quantitativo, realizado em hospital universitário, sendo incluídas todas as gestantes com diabetes pregestacional e gestacional ou com hiperglicemia leve que não desenvolveram intercorrências clínicas na gestação e que tiveram parto no Hospital das Clínicas, Faculdade de Medicina de Botucatu, Universidade Estadual Paulista (HC-FMB-Unesp). MÉTODOS: Trinta gestantes tratadas com dieta foram acompanhadas em ambulatório e 20 tratadas com dieta e insulina foram abordadas com hospitalizações curtas e frequentes. Foram obtidos custos diretos (pessoal, material e exames) e indiretos (despesas gerais) a partir de dados contidos no prontuário e no sistema de custo por absorção do hospital e posteriormente calculado o custo-benefício. RESULTADOS: O sucesso do tratamento das gestantes diabéticas evitou o gasto de US$ 1.517,97 e US$ 1.127,43 para pacientes hospitalizadas e ambulatoriais, respectivamente. O custo-benefício da atenção hospitalizada foi US$ 143.719,16 e ambulatorial, US$ 253.267,22, com rentabilidade social 1,87 e 5,35 respectivamente. CONCLUSÃO: A análise árvore de decisão confirma que o sucesso dos tratamentos elimina custos no hospital. A relação custo-benefício indicou que o tratamento ambulatorial é economicamente mais vantajoso do que a hospitalização. A rentabilidade social de ambos os tratamentos foi maior que 1, indicando que ambos os tipos de atendimento à gestante diabética têm benefício positivo.

Energy system contributions in indoor rock climbing

The present study cross-sectionally investigated the influence of training status, route difficulty and upper body aerobic and anaerobic performance of climbers on the energetics of indoor rock climbing. Six elite climbers (EC) and seven recreational climbers ( RC) were submitted to the following laboratory tests: ( a) anthropometry, (b) upper body aerobic power, and ( c) upper body Wingate test. on another occasion, EC subjects climbed an easy, a moderate, and a difficult route, whereas RC subjects climbed only the easy route. The fractions of the aerobic (WAER), anaerobic alactic (W-PCR) and anaerobic lactic (W-[La(])-) systems were calculated based on oxygen uptake, the fast component of excess post-exercise oxygen uptake, and changes in net blood lactate, respectively. on the easy route, the metabolic cost was significantly lower in EC [ 40.3 ( 6.5) kJ] than in RC [60.1 ( 8.8) kJ] ( P < 0.05). The respective contributions of the WAER, WPCR, and W-[La(])- systems in EC were: easy route = 41.5 (8.1), 41.1 (11.4) and 17.4% (5.4), moderate route = 45.8 (8.4), 34.6 (7.1) and 21.9% (6.3), and difficult route = 41.9 (7.4), 35.8 (6.7) and 22.3% (7.2). The contributions of the WAER, WPCR, and W-[La(])- systems in RC subjects climbing an easy route were 39.7 (5.0), 34.0 (5.8), and 26.3% (3.8), respectively. These results indicate that the main energy systems required during indoor rock climbing are the aerobic and anaerobic alactic systems. In addition, climbing economy seems to be more important for the performance of these athletes than improved energy metabolism.

Development of a simple and versatile ultrafiltration system for the fractionation of aquatic humic substances

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)