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

Effect of silver-coated silica nanoparticles on the thermal conductivity of thermally activated acrylic resin / Efeito das nanopartículas de sílica revestidas por prata na condutividade térmica da resina acrílica ativada termicamente

Objective: Thermally activated acrylic resins (RAATs) are widely used in dentures as a base material due to their good dimensional stability and biocompatibility. However, their low thermal conductivity is a disadvantage, as it affects acceptance when using dental prostheses. Thus, the objective of this work was to measure the conduction heat in RAATs with and without incorporation of silica and silver nanoparticles (NP) and rigid reline (RR). Material and Methods: For this, samples were made and divided into 10 groups (n = 6). The first five groups were 2-mm-thick samples: G1 (RAAT control), G2 (RAAT + RR control), G3 (RAAT and NP + RR), G4 (RAAT + RR and NP), and G5 (RAAT and RR modified by NP). In the other five groups, 8-mm-thick samples were made: G6 (RAAT control), G7 (RAAT + RR control), G8 (RAAT and NP + RR), G9 (RAAT + RR and NP), and G10 (RAAT and RR modified by NP). The heat that cross the surface of the specimens was quantified using a wireless device. The data were submitted to two-factor ANOVA statistical analysis and Tukey ́s test with a 5% significance level. Results: After measuring the temperature variation as a function of time, it can be observed that there was a statistically significant difference for thermal conduction between the control groups and those modified with NP. Conclusion: Thus, it was possible to conclude that the NP improved the heat conduction in RAAT and in the RR because the nanoparticles have a higher thermal conductivity. (AU)

Objetivo: As resinas acrílicas termicamente ativadas (RAATs) são amplamente utilizada em próteses dentárias como material de base, pois possuem uma boa estabilidade dimensional e biocompatibilidade. Porém, como desvantagem, possuem baixa condutividade térmica, o que prejudica a aceitação do uso de próteses dentárias. Assim, o objetivo deste trabalho foi medir a condução de calor em RAAT com e sem incorporação de nanopartículas de sílica e prata (NP) e reembasador rígido (RR). Material e Métodos: Para isso, foram confeccionadas amostras que foram divididas em 10 grupos (n=6). Os primeiros cinco grupos eram amostras de 2 mm de espessura: G1 (RAAT controle), G2 (RAAT + RR controle), G3 (RAAT e NP + RR), G4 (RAAT + RR e NP) e G5 (RAAT e RR modificados por NP). E nos outros cinco grupos foram feitas amostras com espessura de 8 mm: G6 (RAAT controle), G7 (RAAT + RR controle), G8 (RAAT e NP + RR), G9 (RAAT + RR e NP) e G10 (RAAT e RR modificados por NP). O calor percorrido pela superfície dos corpos ­ de prova foi quantificado por meio de um dispositivo sem fio. Os dados foram submetidos à análise estatística ANOVA dois fatores e teste de Tukey com 5% de significância. Resultados: Após medir a variação da temperatura em função do tempo, pode-se observar que houve diferença estatisticamente significante para a condução térmica entre os grupos controle e os modificados com NP. Conclusão: Assim, foi possível concluir que a NP melhorou a condução de calor na RAAT e no RR, pois as nanopartículas apresentam maior condutividade térmica. (AU)

EFECTO DE LA ADICIÓN DE MATERIALES RECICLABLES EN LA MASILLA PARA CONSTRUCCIÓN LIVIANA RESPECTO A LA CAPACIDAD CALORÍFICA, AISLAMIENTO TÉRMICO Y ACÚSTICO / EFFECT OF THE ADDITION OF RECYCLABLE MATERIALS IN THE LIGHTWEIGHT CONSTRUCTION MASTIC REGARDING THE CALORIFYING CAPACITY, AND THERMAL AND ACOUSTIC INSULATION

Este trabajo discute los resultados de la investigación experimental conducida para estudiar la inclusión de materiales reciclables como cascarilla de arroz, poliestireno expandido (icopor) y tereftalato de polietileno ­PET­ en la masilla para construcción liviana empleada para la fabricación de placas de Drywall como respuesta a la minimización del impacto ambiental y al aprovechamiento de las propiedades de los materiales desechados que son nuevamente introducidos en procesos productivos con el fin de obtener baja conductividad térmica, alta capacidad calorífica, alta capacidad de absorción sonora y cumplir con la normativa internacional para materiales de construcción; para ello se realizaron pruebas para medir cuatro propiedades como son el aislamiento térmico, capacidad calorífica y pruebas físico-mecánicas (resistencia a la flexión y resistencia a la tracción de clavo) por medio de probetas, teniendo en cuenta la normativa ASTM C 1396/C1396M-04 y ASTM C473-03, mientras que para la prueba de aislamiento acústico se utilizaron las normas ISO 16283-1 e ISO 717-1; los resultados obtenidos se procesaron aplicando un análisis estadístico multivariado empleando el software Statgraphics Centurion XVII que estableció los valores máximos y mínimos, la correlación de Pearson y ordinal de Spearman como método de análisis para el reporte del material más eficiente respecto a las cuatro propiedades medidas. La cascarilla de arroz, sustituyendo en un 60 % el peso del yeso en la masilla original, reportó los mejores resultados en cada una de las cuatro pruebas realizadas a lo largo de la investigación; de esta manera se confirma que es un material adecuado para la implementación en procesos de construcción liviana dado que demuestra que los materiales reciclables son eficientes y además poseen propiedades específicas como resistencia, liviandad y flexibilidad que le dan un valor agregado para ser utilizados nuevamente como reemplazo de materiales tradicionales.

This paper discusses the results of the experimental research conducted to study the inclusion of recyclable materials such as rice husks, expanded polystyrene (Styrofoam), and polyethylene terephthalate (PET) in the mastic for lightweight construction used for the manufacture of Drywall plates in response to the minimization of the environmental impact, and the use of the properties of discarded materials that are, once again, introduced in productive processes to obtain low thermal conductivity, high heat capacity, high sound absorption capacity and that comply with international standards for construction materials. For this purpose, tests to measure four properties such as Thermal Insulation, Calorific Capacity and Physical-Mechanical Testing (Flexural Resistance and Nail Tensile Strength) were carried out by means of test pieces taking into account the ASTM C1396 / C1396M - 04 and ASTM C473 - 03, while ISO 16283-1 and ISO 717-1 were used for the acoustic insulation test. The results obtained were processed by applying a multivariate statistical analysis using the Statgraphics Centurion XVII-2015 software that established the maximum and minimum values, Pearson's correlation and Spearman's ordinal as the analysis method for reporting the most efficient material regarding the four measured properties. Rice husk, replacing by 60% the weight of plaster in the original mastic, reported the best results in each of the four tests carried out throughout the research. In this way, it is confirmed that it is a suitable material for the implementation in lightweight construction processes as it shows that recyclable materials are efficient and also have specific properties such as strength, lightness and flexibility that give an added value to be used again as a replacement of traditional materials.

Variations in ß(T)-function due to addition of LiI-4AgI system / Variaciones en la función ß(T) - por la adición del sistema LiI-4AgI / Variações na função ß(T) devido a adição do sistema Lil-4Agl

Abstract Impedance spectroscopy measurements of the LiI-4AgI samples, in the frequency range 20 Hz-1 MHz, and in the temperature range between 353 K and 378 K were made. Both pure and lithium-doped silver iodide showed blocking phenomena in the electrodes and the grain boundary. The blocking phenomena allowed a change in the transport properties of the pure compound in respect to the doped compound as the temperature varied. The curves of electrical modulus in the LiI-4AgI system show asymmetric peaks corresponding with a weak correlation between mobile ions in the diffusion process. The electrical conductivity in the Agl-Lil system can be described using a stretched relaxation function of the Kohlrausch-Williams-Watts (KWW) type. We speculat e that the phase of lithium dissolved in the silver iodide favors the formation of islands that disperses the conductivity due to the modification of the relationship among the microscopic energies: microscopic energy and migration energy.

Resumen Se tomaron medidas de espectroscopia de impedancia de muestras de Lil-4Agl en el rango de frecuencia de 20 Hz-1 MHz y en el rango de temperatura entre 353 K y 378 K. Tanto el litio puro como el litio dopado con ioduro de plata mostraron fenómenos de bloqueo en los electrodos y la frontera de grano. Los fenómenos de bloqueo permitieron un cambio en las propiedades de transporte del compuesto puro respecto del compuesto dopado a medida que variaba la temperatura. Las curvas del módulo eléctrico en el sistema LiI-4AgI muestran picos asimétricos correspondientes a una débil correlación entre iones móviles en el proceso de difusión. La conductividad eléctrica en el sistema Agl-Lil se puede describir usando una normalización de la función de relajación del tipo Kohlrausch-Williams-Watts (KWW). Especulamos que la fase de litio disuelto en ioduro de plata favorece la formación de islas que dispersan la conductividad debido a la modificación de la relación entre las energías microscopias: energía microscópica y energía de migración.

Resumo Foram realizadas medidas de espectroscopia de impedancia de amostras de Lil-4Agl na faixa de frequência de 20 Hz - 1 MHz e na faixa de temperatura entre 353 e 378 K. Tanto o litio puro como o litio contaminado com iodeto de prata mostram fenômenos de bloqueio nos eletrodos e nos limites do grão. Os fenômenos de bloqueio permitiram uma mudança nas propriedades de transporte do composto puro em respeito ao composto contaminado, à medida que se variava a temperatura. As curvas do módulo elétrico no sistema Lil-4Agl mostraram picos assimétricos correspondentes a uma correlação débil entre ions móveis no processo de difusão. A condutividade elétrica no sistema AgI-Lil pode ser descrita utilizando uma normalização da função de relaxação do tipo Kohlrausch- Williams-Watts (KWW). Especulamos que a fase de litio dissolvida em iodeto de prata favorece a formação de ilhas que dispersam a condutividade devido a modificação da relação entre as energias microscópicas: energia microscópica e energia de migração.

Radio-graphene in Theranostic Perspectives / 대한핵의학회잡지

Owing to its unique physicochemical properties such as high surface area, notable biocompatibility, robust mechanical strength, high thermal conductivity, and ease of functionalization, 2D-layered graphene has received tremendous attention as a futuristic nanomaterial and its-associated research has been rapidly evolving in a variety of fields.With the remarkable advances of graphene especially in the biomedical realm, in vivo evaluation techniques to examine in vivo behavior of graphene are largely demanded under the hope of clinical translation. Many different types of drugs such as the antisense oligomer and chemotherapeutics require optimal delivery conveyor and graphene is now recognized as a suitable candidate due to its simple and high drug loading property. Termed as ‘ radio-graphene’, radioisotope-labeled graphene approach was recently harnessed in the realm of biomedicine including cancer diagnosis and therapy, contributing to the acquisition of in vivo information for targeted drug delivery. In this review, we highlight current examples for bioapplication of radiolabeled graphene with brief perspectives on future strategies in its extensive bio- or clinical applications.

Thermophysical properties of the pequi pulp in different concentrations / Propriedades termofísicas da polpa de pequi em diferentes concentrações

The pequi fruit (Caryocar coriaceum Wittm) has a great economic interest, regarding the use of its fruits in cooking as a source of vitamins and extraction of oils for the manufacture of cosmetics. However, are unknown studies on the thermophysical properties (specific heat, thermal diffusivity and thermal conductivity), in which properties are very important to the pulp being favored in an industrial level. The work in question was aimed at studying the physical properties of the pequi pulp with levels of total soluble solids of 6, 8, 10 and 12 °Brix. The physical properties were studied: specific heat, thermal diffusivity and thermal conductivity. The specific heat of the pulps was determined using the method of mixtures, the thermal diffusivity was determined using the method proposed by Dickerson and the thermal conductivity KD-2 equipment. Therefore, it was found that the specific heat tended to increase with the increase of temperature and total soluble solids content of the pulp. The thermal diffusivity of the pequi pulp decreased with the increase in total soluble solids; the thermal conductivity of the pulp did not show a definite increase in temperature trend in the pulps investigated.

O fruto do pequi (Caryocar coriaceum Wittm) possui um grande interesse econômico, no que se refere ao uso de seus frutos na culinária como fonte de vitaminas e na extração de óleos para a fabricação de cosméticos. Todavia, são desconhecidos estudos voltados para as propriedades termofísicas (calor específico, difusividade térmica e condutividade térmica), nas quais são propriedades de suma importância para que a polpa seja beneficiada a nível industrial. O trabalho em questão teve como objetivo estudar as propriedades físicas da polpa de pequi com teores de sólidos solúveis totais de 6, 8, 10 e 12 oBrix. As propriedades físicas estudadas foram: calor específico, difusividade térmica e condutividade térmica. O calor específico das polpas foi realizado por meio do calorímetro de mistura, a difusividade térmica utilizando-se o método do cilindro de Dickerson e a condutividade térmica no equipamento KD-2. Portanto, constatou-se que o calor específico apresentou tendência de aumento com o aumento da temperatura e do teor de sólidos solúveis totais das polpas. A difusividade térmica da polpa de pequi diminui com o aumento dos sólidos solúveis totais, a condutividade térmica das polpas não apresentou uma tendência definida com o aumento da temperatura nas polpas estudadas.

The Mechanism of Low Temperature Burn and Clinical Cases

PURPOSE: This study was designed to better understand the mechanism of low temperature burn and to show clinical cases of low temperature burn. METHODS: The local temperature increase of electric pad was investigated at 4 different surface cooling conditions. Blocks (5x5x2 cm3) made of silicone rubber, aluminum, or urethane foam were placed on the top of the electric pad, and temperature between the blocks and electric pad was measured up to 7 hours after switching on maximally (level 7). Each block has different thermal conductivity (TC) and TC of silicone rubber (0.2 W/m.degrees C) is similar to TC of human skin (0.37 W/m.degrees C). TC of aluminum is higher and TC of urethane foam is lower than TC of human skin. Experiments were performed on two occasions with or without a blanket covering over the electric pad and blocks. RESULTS: The initial surface temperature (18degrees C) of the electric pad under the silicone rubber block was elevated to 36.5degrees C at 1 hour, 41.8degrees C at 3 hours, 44.2degrees C at 5 hours, and 45.5degrees C at 7 hours. After covering the electric pad and blocks with a blanket, the temperature of the electric pad under the silicone rubber block was elevated to 40.9degrees C at 1 hour, 51.8degrees C at 3 hours, 56.1degrees C at 5 hours and 58.1degrees C at 7 hours. Under the same conditions, surface temperatures under the urethane foam and aluminum blocks were 70.8degrees C and 50.degrees C respectively at 7 hours. CONCLUSION: The local temperature increase of electric pad was dependent on the surface cooling conditions, heating time and blanket covering over the electric pad. The surface temperature increased to 56.1degrees C at 5 hours after blanket covering over the silicone block which temperature can cause severe injuries on the human skin within a minute.

Effect of double glazing on the thermal performances of a solar still coupled to a condenser

The solar distillation is seen as a promising technique which gives an effective solution for disinherited regions where there is penury of drinking water. The solar still is an apparatus which produces a pure water from a briny water and it works with a solar energy. Several prototypes have been conceived in order to ameliorate their efficiency. In this paper, we have investigated the effect of a double cover on the thermal behaviour and on the daily production of a solar still coupled with a condenser

The design of heat dissipation of the field low temperature box for storage and transportation / 生物医学工程学杂志

Because of the compact structure of the field low temperature box for storage and transportation, which is due to the same small space where the compressor, the condenser, the control circuit, the battery and the power supply device are all placed in, the design for heat dissipation and ventilation is of critical importance for the stability and reliability of the box. Several design schemes of the heat dissipation design of the box were simulated using the FLOEFD hot fluid analysis software in this study. Different distributions of the temperature field in every design scheme were constructed intimately in the present study. It is well concluded that according to the result of the simulation analysis, the optimal heat dissipation design is decent for the field low temperature box for storage and transportation, and the box can operate smoothly for a long time using the results of the design.

A finite element thermal analysis of various dowel and core materials.

Aim: Thermal analysis of the temperature and stress distribution of parallel sided, threaded and non-threaded dowels and core materials under thermal loading within a maxillary central incisor using a three dimensional finite element study. Materials and Methods: 3D models of endodontically treated maxillary central incisor with parallel sided, threaded and non- threaded post and core materials were simulated using the ANSYS software. Materials simulated were parallel sided cast gold post and core, parallel sided fibre reinforced composite (FRC) post and core, and parallel sided, threaded, prefabricated stainless steel post and amalgam core. Thermal loads simulating hot (60 degree C/ 333K) and cold (15 degree C/288K) liquid were applied for 15 seconds at the incisal edge. The temperature changes at the selected nodes were obtained on the various post and core materials, interface between post and dentin, interface between core and dentin, within the dentin and within the cement layer. Results: Temperature and stress distribution pattern were represented in numerical and color coding and results interpreted. Thermal stresses arises as a result of temperature changes. A decreased temperature gradient of the metallic dowels and core (T1 hot - 0.002K, T3 hot - 1.071K, T1 cold -0.99K, T3 cold - 0K) were obtained than that of the FRC dowel and core of 1.982K(hot) and1.55K(cold) respectively due to the higher thermal conductivity of the metals. Higher thermal stress values of 3.567 Mpa(hot) and 3.092 Mpa(cold) respectively were obtained for the FRC dowels and higher stress values of 39.679 Mpa(hot) and 57.855 Mpa(cold) respectively were also obtained for the FRC cores. These values indicated that thermal stresses of the FRC dowel and core were greater than that of cast gold dowel and core and prefabricated stainless steel dowel and amalgam core due to its high coefficient of thermal expansion. Maximum stress values of the FRC dowel and core of 1.87 Mpa(hot) and 2.57 Mpa(cold) respectively were also generated in the cement layer, core and metal ceramic crown. The junction of the metal ceramic crown and dentin demonstrated the maximum stress. Higher thermal stress values of 59.162 ± 10 Mpa were obtained in the restoration and the coronal portion of the dentin than the stress levels of .0039 ± 10Mpa in the supporting bone due to an increased thermal expansion. Conclusion: Non-metallic dowel and core materials such as fibre reinforced composite dowels (FRC) generate greater stress than metallic dowel and core materials. This emphasized the preferable use of the metallic dowel and core materials in the oral environment.

Cavitation and boiling of bubbles at the focal region during high intensity focused ultrasound exposure / 生物医学工程学杂志

High intensity focused ultrasound (HIFU) is a very complex transient process and can cause tissue coagulation necrosis. The cavitation and boiling behaviour of bubbles in the focal region play very important roles throughout an injury process. This paper reviews the research done by domestic and foreign scholars on behaviours of bubbles in HIFU irradiation process and summarizes in the focal region bubble cavitation and boiling generation, related detective means and relationships with hyperecho, temperature rise of the focus and injury shape.

Effects of electrocautery to provoke endovascular thermal injury / Efeitos do eletrocautério para provocar lesão térmica endovascular

PURPOSE: To investigate the effects of a new electrocautery device to provoke endovascular venous thermal injury. METHODS: An experimental endovascular electrocautery was placed inside eight ex-vivo bovine saphenous veins models. Each one was divided in eight segments and progressive intensities of electric energy liberated. The macroscopic and microscopic effects were analyzed. RESULTS: Forty bovine saphenous veins segments were studied. The higher the electric energy applied the greater the nuclear picnosis and more intense the cytoplasmatic shrinkage and electrocoagulation effects. CONCLUSION: The experimental endovascular electrocautery device demonstrated to be both capable of inducing the destruction of the intimal layers of the studied vein model and provoke endovascular thermal injury.

OBJETIVO: Investigar os efeitos de um modelo experimental de eletrocautério em provocar lesão venosa térmica endovascular. MÉTODOS: O eletrocautério endovascular foi colocado dentro de oito modelos experimentais de veia safena bovina. Cada uma foi dividida em oito segmentos e intensidades progressivas de energia elétrica liberada. Os efeitos macroscópicos e microscópicos foram analisados. RESULTADOS: Foram estudados quarenta segmentos de veia safena bovina. Quanto maior a energia elétrica aplicada pelo eletrocauterizador endovascular maiores foram as alteraçoes de picnose nuclear e mais intensa a retração citoplasmática observada. CONCLUSÃO: O eletrocautério endovascular experimental demonstrou ser capaz de induzir a destruição da camada íntima e provocar lesão térmica endovascular.

Avaliação da estabilidade de soluções modelo (CMC-Sacarose) em recongelados / Model solutions (CMC-sucrose) stability evaluation after several freezing process

O objetivo deste trabalho foi avaliar a estabilidade de soluções modelo pela determinação da temperatura de início de congelamento depois de repetidos processos de congelamento. As soluções utilizadas eram compostas por água, sacarose e Carboxi-Metil-Celulose (CMC). Foram avaliadas as concentrações de sacarose de 15 e 31,1% (m/m total da amostra) e do espessante de 0,5, 1 e 1,5% (m/m total da amostra). Buscou-se determinar a possibilidade de reutilização de soluções modelo em ensaios de congelamento. Com os resultados obtidos pode-se concluir que para a concentração de espessante de 0,5% não houve alteração da capacidade de retenção de água. A variação da concentração de sacarose não influenciou a estabilidade das soluções durante o estudo.

Transient thermal and stress analysis of maxillary second premolar tooth using an exact three-dimensional model.

Aim : In this paper, the temperature and stress distributions in an exact 3D-model of a restored maxillary second premolar tooth are obtained with finite element approach. Objective : The carious teeth need to restore with appropriate restorative materials. There are too many restorative materials which can be used instead of tooth structures; since tooth structures are being replaced, the restorative materials should be similar to original structure as could as possible . Materials and Methods : In the present study, a Mesial Occlusal Distal (MOD) type of restoration is chosen and applied to a sound tooth model. Four cases of restoration are investigated: two cases in which base are used under restorative materials and two cases in which base is deleted. The restorative materials are amalgam and composite and glass-inomer is used as a base material. Modeling is done in the solid works ambient by means of an exact measuring of a typical human tooth dimensions. Tooth behavior under thermal load due to consuming hot liquids is analyzed by means of a three dimensional finite element method using ANSYS software. The highest values of tensile and compressive stresses are compared with tensile and compressive strength of the tooth and restorative materials and the value of shear stress on the tooth and restoration junctions is compared with the bond strength. Also, sound tooth under the same thermal load is analyzed and the results are compared with those obtained for restored models. Results : Temperature and stress distributions in the tooth are calculated for each case, with a special consideration in the vicinity of pulp and restoration region. Numerical results show that in two cases with amalgam, using the base material (Glass-ionomer) under the restorative material causes to decrease the maximum temperature in the restorative teeth . In the stress analysis, it is seen that the principal stress has its maximum values in composite restorations. Conclusion : The maximum temperatures are found in the restoration case of amalgam without base. Besides, it is found that restoration has not any influence on the stress values at DEJ, such that for all cases, these values are close to sound tooth results.

Univariate analysis of influential parameters for lingual temperature / 生物医学工程学杂志

The parameters which can influence heat transfer of tongue were analyzed in order to reveal the reason why the tongue temperature fields of people with different diseases are distinct. Firstly, the research parameters were determined by experiment results, including the reference humidity of tongue surface, metabolic heat of tongue tissue, the entrance position of root vessel, the diameter of root vessel, the blood flow rate, and the bifurcation exponent of vascular tree. Then the effect of each parameter on the value and the distributing rule of tongue temperature field was analyzed by using a mathematic model of lingual temperature field. Results show that all these parameters have effects on the temperature value of tongue. The reference humidity of tongue surface, the metabolic heat of tongue tissue and the entrance position of root vessel are distinct influences on the distributing rule of tongue temperature.

Efecto antinociceptivo de Critoniella acuminata, Physalis peruviana y Salvia rubescens / Antinociceptive effect of Critoniella acuminata, Physalis peruviana and Salvia rubescens

Se evaluó el efecto antinociceptivo de extractos, fracciones y compuestos de Critoniella acuminata, Physalis peruviana y Salvia rubescens mediante los métodos de placa caliente, contorsiones abdominales inducidas por ácido acético y ensayo de la formalina. La fracción de Critoniella acuminata en dosis de 100 mg/kg p.o. presentó actividad antinociceptiva al aumentar el tiempo de reacción del animal ante la aplicación de un estímulo térmico (método de la placa caliente), mientras que la fracción de Physalis peruviana, en una dosis de 100 mg/kg p. o., ejerce un efecto antinociceptivo frente al dolor generado por estímulos químicos (dolor visceral agudo) al inhibir en un 40 por ciento las contorsiones abdominales inducidas por ácido acético y el número de lamidos durante la fase ii (dolor inflamatorio agudo) en el ensayo de formalina. Estos resultados sugieren que la ayapina y la fracción de Physalis peruviana estudiadas tienen actividad antinociceptiva, con posibles mecanismos de tipo opioide y aine, respectivamente.

The antinociceptive effect of extracts, fractions and compounds of Critoniella acuminata, Physalis peruviana and Salvia rubescens were evaluated by the follow methods: Hot Plate test, acetic acid induced abdominal writhing and Formalin test. The fraction of Critoniella acuminata at doses of 100mg/kg p.o. exhibited antinociceptive effect in the hot plate test; while Physalis peruviana fraction at doses of 100 mg/kg p.o., showed an antinociceptive effect against the pain chemically induced. This fraction produced 40 percent inhibition of the acetic acid induced writhing (acute visceral nociception) and the licks during phase ii (acute inflammatory nociception)of the formalin test. The findings of this experimental study suggest that fractions of Critoniella acuminata and Physalis peruviana possess antinociceptive activity with opioid and nsaid-like mechanisms respectively.

Estimating temporal and seasonal variation of ventilation coefficients

The main objective of a research program, whose output is presented here, has been to estimate "Ventilation Coefficients", a critical parameter in determining air pollution concentration near the surface ground which signifies the ability for natural ventilation of an air shed in an urban or rural area. Relevant measured data from the city of Tehran has been used to calibrate and further demonstrate the validity of the mathematical model developed. Since most polluted mega cities require significant air pollution modeling activities, capable of providing relatively reliable outputs, calculating such highly important parameter is by far the most important outcome of this research. The Ventilation Coefficients have been estimated assuming normal adiabatic lapse rates and utilizing ten-year daily atmospheric radio-sound data. Mean Maximum Mixing Depth, Wind Speed at Mean Maximum Mixing Depth, and the Ventilation Coefficients have been computed and as a result it has been noted that despite the fact than Mean Maximum Mixing Depth peacks in June and Wind Speed Coefficient to remain at its peack almost constant over April-June time span. It may also be observed for an urban area such as Tehran, the Ventilation Coefficient stands maximum in spring at 22329.17 m[2]/s and minimum in fall at 22329.17 m[2]/s

Avaliação da acurácia de diversos métodos para determinação de ácidos graxos voláteis e alcalinidade a bicarbonato para monitoramento de reatores anaeróbios / Evaluation of the accuracy of several methods for determination of volatile fatty acids and bicarbonate alkalinity for the monitoring of anaerobic reactors

Sistemas de tratamento anaeróbios são sensíveis às mudanças de condições ambientais que influenciam no metabolismo dos microrganismos responsáveis pela estabilidade do processo. Os objetivos deste trabalho foram (i) avaliar a acurácia de métodos que determinam os parâmetros de controle ácidos graxos voláteis (AGV) e alcalinidade a bicarbonato (AB) em amostras preparadas com concentrações de 50 a 1000 mg/L e, (ii) verificar diferentes procedimentos de remoção de CO2 formado durante titulação ácida das amostras. A partir do teste estatístico de Tukey aplicado aos resultados obtidos, observou-se que os métodos Kapp e DiLallo & Albertson com utilização de ultra-som para a remoção de CO2 do meio líquido apresentaram os melhores resultados para AGV. Os métodos da Condutividade, Kapp e Jenkins se destacaram na determinação de AB.

Anaerobic treatment systems are sensitive to the environmental condition changes. Such changes may have influence on the metabolism of the microorganisms responsible for the process stability. The aims of this work were (i) to evaluate the accuracy of methods to determine control parameters volatile fatty acids (VFA) and bicarbonate alkalinity (BA) in samples prepared with concentrations from 50 to 1000 mg/L and, (ii) to verify different procedures of the CO2 removal formed during the acid titration of the samples. From the Tukey statistical test applied to the obtained results it was observed that the Kapp and DiLallo & Albertson methods using sonic equipment to remove CO2 from the liquid presented better results for VFA. The Conductivity, Kapp and Jenkins methods were considered the most reliable for BA determination.

Thermal tactile Vs. Neuromuscular electric stimulation in the rehabilitation of stroke-induced dysphagia

To study the effect of neuromuscular electric stimulation on the swallow functional score in stroke patients having dysphagia and compare the effect of neuromuscular and thermal tactile stimulation on its rehabilitation. Fifty patients with dysphagia due to stroke were included. They were divided into two equal groups according to the rehabilitation programs they received. Group I received neuromuscular electric stimulation sessions on the neck one hour daily for 12 weeks. Group II received tactile thermal stimulation on the anterior faucial arch one hour daily for 12 weeks. Swallow functional score for dysphagia assessment using the modified barium swallow [MBS] was done for both groups, at the start and at 4 weeks, 8 weeks and 12 weeks. No statistically significant difference was detected between Groups I and II as regards the swallowing score at the start, 4 weeks and 8 weeks [p>0.05]. But there was a statistically significant higher score at 12 weeks [p<0.05]. There was a statistically significant higher change in the score from the start till 12 weeks in Group I as compared to Group II [p<0.05]. Also, there was a higher dysphagia score with hemispherical lesions over the 12 weeks of rehabilitation program in Group I [p<0.05] which was seen only in patients having chest problems in Group II [p<0.05]. The electrical stimulation has the advantage of being Non-invasive and actively assisting swallowing. Thus it can be used as an alternative treatment for dysphagia. It also helps in the restoration of the normal swallowing mechanism and decreases the incidence of the subsequent complications of dysphagia. To use neuromuscular electric stimulation of the neck muscles instead of thermal tactile stimulation in rehabilitation of dysphagia secondary to stroke. Further studies are needed to detect its long term effect on dysphagia rehabilitation

Effects of probe configuration on the measurement of bio-tissue thermal physical parameters using step-temperature technique / 生物医学工程学杂志

The step-temperature technique can be used to measure bio-tissue thermal physical parameters. During the derivation of the step-temperature technique, the measuring probe was assumed to be made of single thermistor sensing element, and the electrical power was assumed to be uniformly distributed throughout the probe bead. However, the probe bead in reality is made of multi-layer structure, and the electrical power is not uniformly distributed throughout the probe bead. In this paper, a mathematical model is built for the step-temperature technique for multi-layer structure probe bead, and a numerical simulation is made to analyze the effects of probe configuration. The physical meaning of the calibrated values of the probe parameters (bead radius and bead thermal conductivity) is also explained theoretically. The results show that the step-temperature technique is still valid for the measurement of bio-tissue thermal physical parameters for the multi-layer structure thermistor probe bead on condition that the bead radius and the bead thermal conductivity are obtained through pre- calibration.