2,263 research outputs found

    Heat Pump For Thermal Power Production In Dairy Farm

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    Besides cold for milk cooling, dairy facilities need to produce hot water for cleaning of tools and equipment. Overall, ohmic heating has been used in dairy farms, increasing power consumption and manufacturing costs. Therefore, as an alternative to reduce power consumption, this paper proposed a water-water heat pumping for simultaneous cold and heat generations. Accordingly, operational tests were performed with three heat-pump prototypes designed for dairy farms, in both laboratory and field levels. At laboratory, tests were carried out using electricity and CNG to define a coefficient of performance (COP). Biogas tests were performed in the field to measure its consumption. CNG average consumption was of 1.118 m(3)/h, while biogas consume was of 2.02 m(3)/h. COP averages of CNG driven pump were 0.20 for cooling, 0.39 for heating, and 0.59 for global. For electric-power driving, COP values were 1.75 for cooling, 2.25 for heating, and 4.00 for global. In addition to evaporating and compensating temperatures, engine rotation was one factor of influence on heat-pump performance.36577979

    Perceived neighborhood environmental attributes associated with walking and cycling for transport among adult residents of 17 cities in 12 countries: The IPEN study

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    Introduction: Prevalence of walking and cycling for transport is low and varies greatly across countries. Few studies have examined neighborhood perceptions related to walking and cycling for transport in different countries. Therefore, it is challenging to prioritize appropriate built-environment interventions. Objectives: The aim of this study was to examine the strength and shape of the relationship between adults’ neighborhood perceptions and walking and cycling for transport across diverse environments. Methods: As part of the International Physical activity and Environment Network (IPEN) adult project, self-reported data were taken from 13,745 adults (18–65 years) living in physically and socially diverse neighborhoods in 17 cities across 12 countries. Neighborhood perceptions were measured using the Neighborhood Environment Walkability Scale, and walking and cycling for transport were measured using the International Physical Activity Questionnaire–Long Form. Generalized additive mixed models were used to model walking or cycling for transport during the last seven days with neighborhood perceptions. Interactions by city were explored. Results: Walking-for-transport outcomes were significantly associated with perceived residential density, land use mix–access, street connectivity, aesthetics, and safety. Any cycling for transport was significantly related to perceived land use mix–access, street connectivity, infrastructure, aesthetics, safety, and perceived distance to destinations. Between-city differences existed for some attributes in relation to walking or cycling for transport. Conclusions: Many perceived environmental attributes supported both cycling and walking; however, highly walkable environments may not support cycling for transport. People appear to walk for transport despite safety concerns. These findings can guide the implementation of global health strategies

    Analysis of different illumination systems for poultry houses of producing fertile eggs

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    Besides the ration, the most consumed input in the productive chain of the poultry industry is the electrical energy, mainly in the production of one day chicks, consuming energy in all the periods, from the egg production to incubation. For the egg production, huge amount of energy is used, in illumination systems of poultry houses in the wave length of the yellow color. The reduction of the energy expenses is tied up to the improvement of the illumination systems, since lamps of higher power, low efficiency and less durable, form the usual system. So, this work, developed in Southwest Parana, has aimed to develop an illumination system which uses a lesser amount of lamps, demanding less energy and long lasting. The illumination systems with sodium vapor 70 W, mixed vapor 250 W and fluorescent HO 110 W lamps were mounted, observing the minimum illuminance of 40 lux. A technical and economical analysis of the data proved that the sodium vapor system is the most economical and durable.Excluindo-se a ração, o insumo mais utilizado na cadeia produtiva da avicultura é a energia elétrica, principalmente na produção de pintinhos de um dia, ocorrendo consumo em todas as fases, desde a obtenção do ovo até a incubação. Para a produção do ovo consome-se grande quantidade de energia elétrica nos sistemas de iluminação dos aviários, devido à necessidade de exposição da poedeira à luz no comprimento de cor amarela. A redução dos gastos com energia elétrica está ligada à melhoria dos sistemas de iluminação, já que o sistema usual é formado por lâmpadas incandescentes de grande potência, baixa eficiência e vida útil curta. Assim, através deste trabalho, desenvolvido em uma granja do Sudoeste do Paraná, objetivou-se desenvolver um sistema de iluminação em que se utilizasse menor quantidade de lâmpadas, demandasse menor carga de energia elétrica e apresentasse maior durabilidade. Foram montados, então, os sistemas de iluminação a vapor de sódio 70 W, vapor mista 250 W e fluorescente HO 110 W, obedecendo-se ao índice mínimo de iluminância de 40 lux. Análise técnico-econômica dos dados levantados durante o período de duração do lote demonstrou que o sistema a vapor de sódio é o mais econômico e durável.42042

    Characterization of particle size of polydispersed biomass by mechanical sieving

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    Polydispersed biomass has as one of the main features variations in particle dimension and size. Mean diameter determination methods by screening are widely used due to their relative simplicity and low cost. However, when applied for heterogeneous materials such as polydispersed biomass, they can lead to misleading results. Thus, we evaluated three methods for determining mean diameter of polydispersed biomass particles, aiming at most accurate results. The methods are based on size fractionation by mechanical sieving: one analytical (Sauter diameter) and two by graphical analysis of particle distribution functions (Mass Distribution Density - MDD and Cumulative/ Augmentative Distribution - CAD). The method based on graphical analysis of mass distribution density (MDD) was the most efficient for sugarcane bagasse analysis, once it enabled detecting different populations and clearly identifying their respective characteristic dimensions. Therefore, it is a powerful tool for particle size analysis of polydispersed biomass.A biomassa polidispersa tem como uma de suas principais características as variações das dimensões e dos formatos de suas partículas. Os métodos de determinação do diâmetro médio por peneiramento, amplamente utilizados devido a sua relativa simplicidade e baixo custo, quando aplicados a materiais heterogêneos, como a biomassa polidispersa, podem levar a resultados equivocados. Assim, com o objetivo de obter resultados mais precisos, foram avaliados três métodos de determinação do diâmetro médio de partículas de biomassa polidispersa, baseados na técnica de fracionamento por peneiramento mecânico: um de forma analítica (Diâmetro de Sauter) e outros dois por meio de análise gráfica das funções de distribuição das partículas (Função de Densidade de Distribuição Mássica e Função Cumulativa/Aumentativa de Distribuição). O método baseado na análise gráfica da função da distribuição da densidade mássica (FDDM) foi o mais eficiente para a análise do bagaço de cana, pois permitiu identificar as diferentes populações existentes e identificar com clareza as dimensões características, mostrando assim ser uma poderosa ferramenta para a análise granulométrica de biomassas polidispersas.36110211

    Water flow influence on performance of a flat solar collector built in thermoplastic

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    Avaliou-se o rendimento térmico de um coletor solar plano construído em termoplástico, em condições reais de operação, registrando as temperaturas de entrada e de saída de água na placa, mediante quatro distintas vazões mássicas de água: 0,026 kg s-1; 0,04 kg s-1; 0,054 kg s-1; e 0,068 kg s-1. Os ensaios foram realizados no Laboratório de Termodinâmica e Energia da Faculdade de Engenharia Agrícola da Unicamp. Com base nos valores de temperatura da água na entrada e na saída das placas, foram calculados os valores de potência térmica [W m-2]. O maior valor médio diário de potência térmica (753 W m-2) foi obtido para a vazão de 0,054 kg s-1. Para a maior vazão (0,068 kg s-1), o valor de potência térmica foi similar ao obtido para a vazão de 0,04 kg s-1 (715 W m-2), mostrando a existência de uma vazão ótima de operação.Avaliou-se o rendimento térmico de um coletor solar plano construído em termoplástico, em condições reais de operação, registrando as temperaturas de entrada e de saída de água na placa, mediante quatro distintas vazões mássicas de água: 0,026 kg s-1; 0,04 kg s-1; 0,054 kg s-1; e 0,068 kg s-1. Os ensaios foram realizados no Laboratório de Termodinâmica e Energia da Faculdade de Engenharia Agrícola da Unicamp. Com base nos valores de temperatura da água na entrada e na saída das placas, foram calculados os valores de potência térmica [W m-2]. O maior valor médio diário de potência térmica (753 W m-2) foi obtido para a vazão de 0,054 kg s-1. Para a maior vazão (0,068 kg s-1), o valor de potência térmica foi similar ao obtido para a vazão de 0,04 kg s-1 (715 W m-2), mostrando a existência de uma vazão ótima de operação.v. 35n.466567

    IMPACT OF SLOW DRYING IN A COLD ROOM ON COFFEE SENSORY, CHEMICAL, AND PHYSICAL PROPERTIES

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    ABSTRACT This study aimed to evaluate the duplicity and synergism of slow drying and storage processes at low temperatures, using a refrigerated room under suitable conditions for coffee fruit just after harvest. A cold room was prepared to receive and store coffee fruit in bulk directly from the field, perform slow drying, and maintain water content at approximately 12% during three months of storage. The room operated at temperatures between 7 and 14 ºC and relative humidity between 37 and 41%. The coffee variety used was the Conilon Yellow 62. The initial water content reduction period from 54% (wb) to 12% (wb) was two months. For comparison, coffee harvested from the same batch was dried on a covered suspended bed. Results showed that the coffee dried and stored in the cold room received a sensory score of 86.41, while that dried on a suspended bed obtained a sensory score of 84.16. Moreover, the coffee dried and stored in the cold room had a higher energy content. Colorimetric analysis showed that the dried grains stored in the cold room had a reduction in the "a" coordinate, indicating an approximation to the green color. The cold room also allowed for extended storage of the coffee grains

    Characterization of particle size of polydispersed biomass by mechanical sieving

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    A biomassa polidispersa tem como uma de suas principais características as variações das dimensões e dos formatos de suas partículas. Os métodos de determinação do diâmetro médio por peneiramento, amplamente utilizados devido a sua relativa simplicidade e baixo custo, quando aplicados a materiais heterogêneos, como a biomassa polidispersa, podem levar a resultados equivocados. Assim, com o objetivo de obter resultados mais precisos, foram avaliados três métodos de determinação do diâmetro médio de partículas de biomassa polidispersa, baseados na técnica de fracionamento por peneiramento mecânico: um de forma analítica (Diâmetro de Sauter) e outros dois por meio de análise gráfica das funções de distribuição das partículas (Função de Densidade de Distribuição Mássica e Função Cumulativa/Aumentativa de Distribuição). O método baseado na análise gráfica da função da distribuição da densidade mássica (FDDM) foi o mais eficiente para a análise do bagaço de cana, pois permitiu identificar as diferentes populações existentes e identificar com clareza as dimensões características, mostrando assim ser uma poderosa ferramenta para a análise granulométrica de biomassas polidispersas.361102113Polydispersed biomass has as one of the main features variations in particle dimension and size. Mean diameter determination methods by screening are widely used due to their relative simplicity and low cost. However, when applied for heterogeneous materials such as polydispersed biomass, they can lead to misleading results. Thus, we evaluated three methods for determining mean diameter of polydispersed biomass particles, aiming at most accurate results. The methods are based on size fractionation by mechanical sieving: one analytical (Sauter diameter) and two by graphical analysis of particle distribution functions (Mass Distribution Density - MDD and Cumulative/ Augmentative Distribution - CAD). The method based on graphical analysis of mass distribution density (MDD) was the most efficient for sugarcane bagasse analysis, once it enabled detecting different populations and clearly identifying their respective characteristic dimensions. Therefore, it is a powerful tool for particle size analysis of polydispersed biomass

    Perceived Neighborhood Environmental Attributes Associated with Walking and Cycling for Transport among Adult Residents of 17 Cities in 12 Countries: The IPEN Study

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    Introduction Prevalence of walking and cycling for transport is low and varies greatly across countries. Few studies have examined neighborhood perceptions related to walking and cycling for transport in different countries. Therefore, it is challenging to prioritize appropriate built-environment interventions. Objectives The aim of this study was to examine the strength and shape of the relationship between adults’ neighborhood perceptions and walking and cycling for transport across diverse environments. Methods As part of the International Physical activity and Environment Network (IPEN) adult project, self-reported data were taken from 13,745 adults (18–65 years) living in physically and socially diverse neighborhoods in 17 cities across 12 countries. Neighborhood perceptions were measured using the Neighborhood Environment Walkability Scale, and walking and cycling for transport were measured using the International Physical Activity Questionnaire–Long Form. Generalized additive mixed models were used to model walking or cycling for transport during the last seven days with neighborhood perceptions. Interactions by city were explored. Results Walking-for-transport outcomes were significantly associated with perceived residential density, land use mix–access, street connectivity, aesthetics, and safety. Any cycling for transport was significantly related to perceived land use mix–access, street connectivity, infrastructure, aesthetics, safety, and perceived distance to destinations. Between-city differences existed for some attributes in relation to walking or cycling for transport. Conclusions Many perceived environmental attributes supported both cycling and walking; however, highly walkable environments may not support cycling for transport. People appear to walk for transport despite safety concerns. These findings can guide the implementation of global health strategies
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