Effect of the chemical composition of fluid foods on the rate of fouling processing during sterilization / Efecto de la composición química de los alimentos líquidos sobre la tasa de procesamiento de la suciedad durante la esterilización

Background: This research was motivated by the determination of the sanitation schedule in the heat exchanger area for some products (milk, avocado juice, and orange juice), as well as the inconsistency of the results of previous studies related to the chemical composition of the fouling layer. Objectives: a) to test the effect of raw material composition on the chemical composition of the fouling layer. b) to test microbial growth's effect on fouling's chemical composition (protein). Methods: mathematical derivation of the formation process of Resistant Dirt Factor (Rd) in the form of an Equation; ANOVA was used to test the effect of the dependent variable (protein) and predictor (microbial). Results: a) The composition of the raw material strongly influences the chemical composition of the fouling layer; b) There is a strong effect between microbial growth and protein content as a fouling composition (p<0.05). Conclusion: A strong influence between microbial growth and the composition of the fouling layer (protein) can close the research gap related to the inconsistency of previous research results (fouling layer composition), so there is no prolonged debate

Antecedentes: Esta investigación fue motivada por la determinación del cronograma de sanitización en el área del intercambiador de calor para diferentes productos (leche, jugo de aguacate y jugo de naranja), así como la inconsistencia de los resultados de estudios previos relacionados con la composición química de la capa de suciedad. Objetivos: a) probar el efecto de la composición de la materia prima sobre la composición química de la capa de suciedad. b) probar el efecto del crecimiento microbiano en la composición química de la capa de suciedad (proteína). Método: etapas del proceso de formación del Factor de Suciedad Resistente (Rd) en forma de una ecuación; Se usó ANOVA para probar el efecto de la variable dependiente (proteína) y el predictor (microbiano). Resultados: a) La composición química de la capa de incrustación está fuertemente influenciada por la composición de la materia prima; b) Existe un fuerte efecto entre el crecimiento microbiano sobre el contenido de proteína como composición de ensuciamiento (p<0.05). Conclusión: Una fuerte influencia entre el crecimiento microbiano y la composición de la capa de incrustación (proteína) puede cerrar la brecha de investigación relacionada con la inconsistencia de los resultados de investigaciones anteriores (composición de la capa de incrustación) para que no haya un debate prolongado

Numerical Study on the Process of Human Brain Cooling Treated by Hemoperfusion Mild Hypothermia / 中国医疗器械杂志

Mild hypothermia, as a common means of intraoperative nerve protection, has been used in clinical practice. Compared with the traditional methods such as freezing helmet and nasopharyngeal cooling, hypothermic blood perfusion is considered to be a promising treatment for mild hypothermia, but it lacks experimental and theoretical verification of its cooling effect. In this study, the commercial finite element simulation software COMSOL combined the Pennes equation with the cerebrovascular network model to construct a new simplified human brain model, which was further used to simulate the cooling process of cerebral hypothermic blood perfusion. When the hypothermic blood perfusion was 33 ℃, the human brain could enter the mild hypothermic state within 4 minutes. By comparing with helmet cooling, the feasibility and efficiency of the blood perfusion scheme were verified. By comparing with the calculation results based on Pennes equation, the rationality of the model constructed in this study were verified. This model can non-intrusively predict the changes of brain temperature during surgery, and provide a reference for the setting of treatment parameters such as blood temperature, so as to provide personalized realization of safer and more effective mild hypothermia neuro protection.

Avaliação da eficácia dos equipamentos de proteção individual para a exposição ocupacional ao frio / Evaluation of the efficacy of personal protective equipment against occupational exposure to cold

INTRODUÇÃO: Os setores climatizados, no ramo de indústrias alimentícias, apresentam variações de temperatura de -35 a 12ºC, as quais são necessárias para garantir a qualidade dos alimentos. Entretanto, essa faixa de temperatura pode ser um agente nocivo para a saúde dos trabalhadores. OBJETIVO:Estudar os parâmetros de exposição ocupacional ao risco frio para estimar o índice de isolamento térmico e determinar a eficácia dos equipamentos de proteção individual. MÉTODOS: Na primeira etapa foram avaliadas as variáveis ambientais (temperatura do ar, velocidade do ar, umidade relativa do ar) e a taxa de metabolismo; na segunda etapa foi determinado o índice de isolamento térmico fornecido; e na terceira etapa foi calculado o índice de isolamento básico de vestuário exigido para manter o equilíbrio térmico e verificada a eficácia dos equipamentos de proteção individual. RESULTADOS: Embora a temperatura do ar seja inferior nas atividades desenvolvidas no túnel de congelamento no setor de embalagem secundária, comparando com as atividades realizadas na câmara de estocagem de operar empilhadeira e transportar produtos, o índice de isolamento básico de vestuário exigido é maior nas atividades desenvolvidas com uso de empilhadeira, mesmo a temperatura sendo superior. Isso ocorre em função da velocidade do ar ser superior nas atividades realizadas nas empilhadeiras. CONCLUSÕES: Em 83,3% das atividades avaliadas a proteção se mostrou eficaz, porém, existe a possibilidade dos indivíduos sentirem desconforto térmico devido ao excesso de roupa fornecida. Apesar de a proteção ser insuficiente em 16,7%, as pausas de recuperação térmica eliminam o risco de hipotermia.

BACKGROUND: The temperature of climate controlled areas in the food industry varies from -35ºC to 12ºC to ensure the quality of food. However, this temperature range might be harmful to the health of workers. OBJECTIVE: To analyze parameters related to occupational exposure to cold risks to calculate clothing insulation indices and establish the efficacy of personal protective equipment (PPE). METHODS: In stage 1 we analyzed environmental variables (air temperature and velocity and relative humidity) and the metabolic rate; in stage 2 we calculated the resultant clothing insulation index; in stage 3 we calculated the basic clothing insulation required to maintain the thermal balance and investigated the efficacy of PPE. RESULTS: While the air temperature was lower for activities developed in the freezing tunnel (secondary packaging department), required basic clothing insulation was higher for activities involving operating forklifts. CONCLUSION: Protection was efficacious for 83.3% of the analyzed activities, however, occurrence of thermal discomfort cannot be ruled out as a function of excessive clothing. Although protection was insufficient for 16.7% of the analyzed activities, breaks for thermal recovery neutralized the risk of hypothermia.

Inherent irreversibility impacts on thermal boundary layer flow over a mobile plate with convective surface boundary conditions

Background:The irreversibility impacts on flow and heat transfer processes can be quantified through entropy analysis. It is a significant tool which can be utilized to deduce about the energy losses. The current study investigates the inherent irreversibility impacts during a flow of boundary layer and heat transfer on a mobile plate. Methods:The flow is examined under thermal radiation and convective heat conditions. The fundamental governing equations of flow and heat phenomenonare transmuted into ordinary differential equations by employing similarity transmutations and shooting technique is utilized in order to solve the resultant equations. The temperature and velocity profiles are acquired to reckon Bejan and entropy generation number. Pertinent results are elucidated graphically for the movement of plate and flow in same and opposite directions.Results:A decline in temperature profile is noted with rise in values of Prin both cases when the movement of surface and free stream is in similar and converse directions. A decrease in temperature is observed for both cases with increase inNRwhile with the rise in Biot numbera, the temperature profile also increases. Entropy generation rate near the surface is high in case when surface and free stream are moving in opposite directions as compared to case when they move in same directions.Conclusions:It is observed that irreversibility impacts are more remarkable when the movement of fluid and plate is in opposite direction. Moreover, irreversibility impacts of heat transfer are prominent in free stream region.

Study on Law of Heat Transfer in Zusanli During the Process of Moxibustion at Different Acupoints / 世界科学技术-中医药现代化

Objectvie: To observe the law of heat transfer in Zusanli during the process of moxibustion. Methods: Thetemperature change of Zusanli was detected by self-made high-precision temperature sensor while moxibustion on lowerextremities acupoints on six meridians of foot in healthy volunteers for fifteen minutes, the temperature change curve andtemperature change rate curve were drawn with Origin software. Results: Temperature change curve of Zusanli was thebiggest when moxibustion on acupoints in stomach meridian of foot yangming, especially for Shangjuxu acupoint.Whenthe acupoints near the level of Zusanli are moxibusted, the temperature change curve of Zusanli changes obviously.Temperature change rate curves of Zusanli were basically in coincidence when moxibustion on lower extremities acupoints on six meridians of foot, and it had a downward trend. Conclusion: Heat transfer between meridians andacupoints have propagated sensation along channel, regional characteristics, consistency of transmission rate, in theprosess of moxibustion.

Estudio de la transferencia de calor en un octavo del conjunto combustible del reactor nuclear de alto desempeño refrigerado por agua supercrítica / Heat transfer study in one eighth of the high performance supercritical water-cooled reactor fuel assembly

El reactor nuclear de agua ligera de alto desempeño es la versión europea del reactor refrigerado por agua supercrítica, propuesto como uno de los candidatos para la Generación IV de reactores nucleares. En este trabajo se evaluó la capacidad para predecir el comportamiento de la transferencia de calor hacia el agua supercrítica en los subcanales de 1/8 del conjunto combustible del HPLWR, mediante códigos de la Dinámica de Fluidos Computacional utilizando dos modelos de turbulencia: el modelo de esfuerzos de Reynolds, desarrollado por Speziale y el modelo k-ω de transporte de esfuerzos cortantes. Se realizó un estudio de sensibilidad de malla que garantizó la independencia de los resultados numéricos respecto del tamaño y distribución de los elementos de la malla. Se calcularon las distribuciones axiales de temperatura en la envoltura y en los elementos combustibles, además de las distribuciones de temperatura del agua en la zona refrigerante y en la zona moderadora. Se compararon los resultados de los dos modelos de turbulencia y se mostró que no se obtuvo ninguna diferencia apreciable en los valores de la temperatura promedio del agua supercrítica calculada con los modelos de turbulencia utilizados. Sin embargo, los resultados numéricos utilizando el modelo de turbulencia SST mostraron mayores valores de temperatura del combustible y de temperatura superficial de la envoltura de los elementos combustibles que los calculados con el modelo SSG

The high-performance light-water nuclear reactor is the European version of the supercritical water-cooled reactor, proposed as one of the candidates for Generation IV of nuclear reactors. This paper assesses the ability to predict the heat transfer behavior to supercritical water in the sub-channels of the 1/8 HPLWR fuel assembly by codes of Computational Fluid Dynamics using two models of turbulence (the Reynolds stress model developed by Speziale and the k-ω shear stress transport model). A mesh sensitivity study was performed to guarantee the independence of the numerical results regardless the size and distribution of the mesh elements. Temperature distributions were calculated in the fuel rods, in the clad, and in water both in the cooling zone and moderator zone. The results of the two turbulence models were compared. No appreciable difference was obtained in the values of the supercritical water average temperature calculated with the turbulence models used. However, the numerical results using the SST turbulence model show higher values regarding the temperature of both fuel rods and clad surface compared to those calculated with the SSG model

Effects of sand therapy temperature on the bone reconstruction and numerical study on the heat transfer / 中国实验动物学报

Objective To investigate the effects of sand therapy temperature on bone reconstruction and numerical study on the heat transfer.Methods CT scan imaging was performed respectively for four times(before and after OA model was set up,and after the first and second weeks during the sand therapy).Import the scan data to MIMICS software,and the changes of femoral bone mass layer were analyzed.After combining the muscle,femur,bone marrow and meshing,the established three-dimensional model of the STL format was introduced into the COMSOL software for heat transfer simulation and effect of stress on bone remodeling induced by temperature field.Results Changes of four CT scan data were analyzed.The soft bone volume was reduced,while the dense and hard bone volume were increased.Numerical simulation on the heat transfer showed the temperature distribution of the thigh and the femur.Conclusions The thermal stress produced by sand therapy temperature exert promoting effect on the femur bone remodeling.

Numerical simulation of heat transfer in a canine knee joint in thermal neutrality: analysis of the influence of different values of blood perfusion and considerations of the blood perfusion rate / Simulação numérica da transferência de calor na articulação do joelho canino em neutralidade térmica: análises das influências dos diferentes valores de perfusão sanguínea e das considerações da taxa de perfusão sanguínea

This study aimed to simulate heat transfer in thermal equilibrium in the canine knee joint. We analyzed the impact of different values of blood perfusion available in the literature and considered blood perfusion rates. The geometric models of canine knee joints were created from a photographic record of a cross section of an anatomical part. Two geometric models were developed: one without the epidermis and one with the epidermis. A heat diffusion equation was used to model the heat transfer phenomenon. Numerical simulations of the canine knee in a thermal neutrality condition were performed using the ANSYS-CFX® program. The simulation results were compared with experimental in vivo data. The smaller percentage differences between the experimental and simulated in vivo results were found in simulations that used the blood flow rate as a function of temperature. The computer simulation proved to be a good alternative to evaluate the temperature of biological tissues.

O presente trabalho visa simular a transferência de calor, em equilíbrio térmico, na articulação do joelho canino e analisar o impacto dos diferentes valores de perfusão sanguínea disponíveis na literatura e das considerações da taxa de perfusão sanguínea. Os modelos geométricos da articulação do joelho canino foram criados com base em um registro fotográfico de um corte transversal de uma peça anatômica. Foram desenvolvidos dois modelos geométricos: 1- sem epiderme e 2 ­ com epiderme. A equação de difusão de calor foi utilizada para modelar o fenômeno de transferência de calor. As simulações numéricas do joelho canino na condição de neutralidade térmica foram realizadas utilizando o programa ANSYS-CFX®. Os resultados da simulação foram comparados com os dados experimentais in vivo. As menores diferenças percentuais, entre o experimento in vivo e os resultados simulados, foram encontradas nas simulações que utilizaram a taxa de perfusão sanguínea em função da temperatura. A simulação computacional mostrou-se uma boa alternativa para avaliar a temperatura dos tecidos biológicos.

Experimental Study of the Heat Transfer Characteristics of Thunder-fire Wonder Moxibustion / 上海针灸杂志

Thunder-fire wonder moxibustion is one of pressing moxibustion therapies and has a very good therapeutic effect on limb pains, furuncle-carbuncle and cold syndrome. To reveal the mechanism of clinical action of ancestors’ thunder-fire wonder moxibustion and seek the physical basis of its therapeutic advantage, this study, by a series of experiments, compared heat transfer regularities of thunder-fire wonder moxibustion versus pure moxa stick in simulated biological tissues under different conditions, preliminarily revealed heat radiation and heat transfer regularities of thunder-fire wonder moxibustion, tried to find pressing strength suitable for clinical operation of pressing moxibustion and had thoughts about changes in the clinical operation of past dynasties.

Study of heat transfer to the implant-bone interface induced by grinding of occlusal surface of implant gold prosthesis / 대한치과보철학회지

PURPOSE: The purpose of this study was to analyze temperature change along the implant-bone interface induced by grinding the occlusal surface of implant gold prosthesis and to compare the temperature generated by grinding of prosthesis with different cooling methods. MATERIALS AND METHODS: The experimental gold prostheses were fabricated with dental gold alloy and castable abutment. The prostheses had 3 cylindrical protrusions on the occlusal surface with 1mm in height. Temperature was measured using 16 thermocouple wires attached to the implant fixture surface and the fixture was embedded in an acrylic resin block inside the 37degrees C water bath. Cylinders were grinded for a period of 30 second with a low-speed handpiece with green stone point. One cylindrical protrusion was grinded without cooling, the second one was grinded with air blow, and the third one was grinded with water-spray. RESULTS: The mean maximum temperature was measured more than 47degrees C of the implant and the maximum temperature was measured at the cervical portion of the implant in the group without cooling. There was statistically significant difference between the group without cooling and the groups with cooling (P.05). CONCLUSION: The results of this study support that the grinding of implant gold prosthesis without cooling may damage the peri-implant tissue. The continuous use of air blow and water-spray adjacent to prosthesis during the grinding of implant gold prosthesis may prove to be beneficial for cooling of the implant.

Numerical Simulation on Phase Change Heat Transfer Process of Biological Tissue in Cryosurgery / 航天医学与医学工程

Objective To study the mechanism of heat transfer by simulating a complete freezing-thawing process of biological tissue.Methods A numerical model of phase change heat transfer in biological tissue was developed with consideration of the difference of thermophysical properties for normal biological tissue and tumor.The biological tissue was assumed as a porous media.The different thermophysical properties between tissue framework and tissue fluid(as water in tissue,etc) were considered.An apparent heat capacity method was applied to solve the phase change heat transfer problem.Results It was showed that the temperature of biological tissue decreased more quickly during the freezing process when the initial cryoprobe temperature was lower and the cooling-rate of cryoprobe was faster.The temperature of biological tissue increased more quickly with faster warming-rate of cryoprobe in the thawing process.It was also showed that the porosity,blood perfusion rate and metabolic heat generation of the biological tissue had effects on tissue freezing temperature in biological tissue.Conclusion To study the thermal process of biological tissue in cryosurgery will be very helpful for further application in cryosurgery.

Effects of Bath Product Named as Sake Concentrate Preparation / 日本温泉気候物理医学会雑誌

We evaluated the effects of SCP bathing on the body by compared with those of a-EG, one of major component of SCP, bathing and the control bathing with tap water alone. Healthy adults were used as the subjects. The effects of bathing on blood pressure and pulse rate were not significantly different among the three bathings, indicating that effects of SCP and α-EG bathing on the lung and heart were similar to those of an ordinary bathing. The surface skin temperature at the forehead decreased more slowly in the subjects after taking a SCP bathing than the other two, suggesting that SCP has temperature holding effects. Also, the results of deep body temperature suggested that α-EG might be related to the heat absorbing effects of SCP bathing, which were significantly marked than those of the other two bathings. The present results regarding the changes in blood flow and deep body temperature during bathing suggest that SCP might produce an environment that allows more rapid heat transfer from bath water to the body and less releasing it from the body. Therefore, we concluded that some component other than α-ethylglucoside would be involved in the heat transfer and moisturizing during SCP bathing. Measurement of skin water content indicated that a region directly contacting with hot water was moisturized in a short time, but this condition quickly returned to the pre-bath condition. Whereas, for regions not contacting with bath water, the skin was much more moisturized by taking SCP bath than the other two bathings. Therefore, it was concluded that SCP is effective for enhancement of skin moisturizing.