Experimental study of fusion and solidification of phase change material (pcm) in spherical geometry

The objective of this work is to investigate the parameters affecting the time for complete solidification and fusion in spherical capsules and develop correlations between this time and the investigated parameters. These correlations will be used in the numerical simulations of latent heat storage systems of the fixed bed type having the phase change material, PCM encapsulated in spherical containers. Four spherical shells of 35, 76, 106 and 131 mm diameter were used at temperatures ranging from -20°C to -5°C for solidification process and temperature of 10°C, 18°C, 25°C for the melting process. Water and mixtures of water and polyethylene glycol in percentages ranging from 7.5% to 50% were used as PCM. Based on the experimental results correlations of the time for complete solidification and complete fusion were developed and compared with the experimental measurements showing good agreement and confirming the suitability of using these correlations to predict the complete phase change times. These correlations are applicable in the ranges: 0.076 m Diameter of spherical capsule 0.131m, 0.1% concentration of polyethylene glycol 0.5%, -20°C Initial temperature of PCM -5°C, 10°C Thermal bath temperature 25°C. The differences between the values predicted by the correlation and the experimental measurements are below 10%.Papers presented to the 12th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Costa de Sol, Spain on 11-13 July 2016

Chemical control of the leprosis mite Brevipalpus phoenicis (Geuskes, 1939) in citrus

A field test was carried out to evaluate the performance of several pesticides for the control of the citrus leprosis mite Brevipalpus phoenicis. The treatments were as follows: A) propargite (0.05; 72% EC) + sulphur (1,0; 75% CS); B) peropal (0.1 kg 25% MP); C) quinomethionate (0.05 kg 70% MP) (standard treatment); D) dicofol + tetradifon (0.2; (16% + 6%) EC; E) propargite (0.075; 72% EC); F) check. The quantities of the products employed in the experiment were based on the commercial formulations for 100 liters of water. Each orange-tree received a single application of ten liters of spray. Five mite evaluations were made: 4 days before spray and 16, 31, 45 and 60 days after the application. All treatments resulted in real pest reduction, higher than 80%, except for A (16 days after the spray) and for treatment C (60 days after the application).Com o objetivo de combater o ácaro Brevipalpus phoenicis (Geijskes), transmissor do vírus da leprose, foi estudada a eficiência de diferentes defensivos químicos. Os tratamentos foram seis, cada um com quatro repetições. A) propargite (0,05; CE 72%) + enxofre (1,0; SC 75%); B) peropal (0,1 kg PM 25%); C) quinometionato (0,05 kg PM 70%) (padrão); D) dicofol + tetradifom (0,2; CE 16% + 6%); E) propargite (0,075; CE 72%); F) testemunha. Cada laranjeira recebeu dez litros de calda numa única aplicação; usou-se o espalhante-adesivo "Extravon", à razão de 20 cm³/l00 litros de calda. Foram feitas cinco avaliações de infestações de ácaro: uma 4 dias antes da aplicação e outras após 16, 31, 45 e 60 dias da pulverização. Com exceção dos tratamentos propargite + enxofre (aos 16 dias) e quinometionato (aos 60 dias), todos os produtos apresentaram porcentagem de redução real da praga acima de 80% nas diferentes épocas de avaliação

Combate experimental ao ácaro da leprose Brevipalpus phoenicis (Geijskes, 1939) em citros

Com o objetivo de combater o ácaro Brevipalpus phoenicis (Geijskes), transmissor do vírus da leprose, foi estudada a eficiência de diferentes defensivos químicos. Os tratamentos foram seis, cada um com quatro repetições. A) propargite (0,05 CE 72%) + enxofre (1,0 SC 75%); B) peropal (0,1 kg PM 25%); C) quinometionato (0,05 kg PM 70%) (padrão); D) dicofol + tetradifom (0,2 CE 16% + 6%); E) propargite (0,075 CE 72%); F) testemunha. Cada laranjeira recebeu dez litros de calda numa única aplicação; usou-se o espalhante-adesivo "Extravon", à razão de 20 cm³/l00 litros de calda. Foram feitas cinco avaliações de infestações de ácaro: uma 4 dias antes da aplicação e outras após 16, 31, 45 e 60 dias da pulverização. Com exceção dos tratamentos propargite + enxofre (aos 16 dias) e quinometionato (aos 60 dias), todos os produtos apresentaram porcentagem de redução real da praga acima de 80% nas diferentes épocas de avaliação.A field test was carried out to evaluate the performance of several pesticides for the control of the citrus leprosis mite Brevipalpus phoenicis. The treatments were as follows: A) propargite (0.05 72% EC) + sulphur (1,0 75% CS); B) peropal (0.1 kg 25% MP); C) quinomethionate (0.05 kg 70% MP) (standard treatment); D) dicofol + tetradifon (0.2 (16% + 6%) EC; E) propargite (0.075 72% EC); F) check. The quantities of the products employed in the experiment were based on the commercial formulations for 100 liters of water. Each orange-tree received a single application of ten liters of spray. Five mite evaluations were made: 4 days before spray and 16, 31, 45 and 60 days after the application. All treatments resulted in real pest reduction, higher than 80%, except for A (16 days after the spray) and for treatment C (60 days after the application)

The double cantilever beam test applied to mode I fracture characterization of cortical bone tissue

the primary objective of this work was to analyse the adequacy of the Double Cantilever Beam(DCB) test in determining fracture toughness under pure mode I loading of cortical bone tissue.A new data reduction scheme based on specimen compliance and the crack equivalent concept was used to overcome the difficulties inherent in crack monitoring during its growth. It provides a complete resistance curve, wich is fundamental in estimating the fracture energy. A cohesive zone model was used to simulate damage initiation and prpagation, thus assessing the efficacy of the proposed testing method and data reduction scheme. Subsequently, the DCB test was applied to evaluate the mode I fracture energy of hidrated and termally dehydrated cortical bone tissue from young bovine femur , in the tangential-longitudinal prpagation system. The results obtained demonstrate the efficaacy of the DCB test and the proposed data reduction scheme on the bone fracture characterization onder mode I loading