Determination of Thermal Physical Parameters and Related Model of Water Extracts of Salvia Miltiorrhiza Radix et Rhizoma / 中国中医药信息杂志

Objective To determine the thermal conductivity under different temperatures and concentrations, and specific heat capacity under different concentrations of water extracts of Salvia Miltiorrhiza Radix et Rhizoma; To establish the mathematical model of thermal conductivity-temperature, thermal conductivity-concentration, thermal conductivity-temperature-concentration and specific heat capacity-concentration of water extracts of Salvia Miltiorrhiza Radix et Rhizoma. Methods Thermal conductivity and specific heat capacity were measured by the instantaneous double hot wire thermal conductivity meter and the electrothermal specific heat capacity meter. Excel, 1stOpt and MATLAB were used to analyze the experimental data. Results The method of using brix to facilitate and accurately characterize the concentration was established. The relationship between the thermal conductivity and the temperature and the concentration of water extracts of Salvia Miltiorrhiza Radix et Rhizoma were all linearly negative (λ=a-bT, λ=a-bC), and the influence of temperature and concentration on the thermal conductivity had a certain interaction. λ=a-bC-cT-dCT could be used as the temperature and the concentration on the thermal conductivity of the integrated role model. And the specific heat capacity of the extract was negatively correlated with the concentration (cp=a-bC). Conclusion The thermal conductivity and the specific heat capacity of the extract of water extracts of Salvia Miltiorrhiza Radix et Rhizoma are different at different temperatures and concentrations, and the model can be used to characterize the changing law of thermodynamics of the extracts. It can provide guidance significance for the thermal characteristics analysis in TCM pharmaceutical process and TCM production equipment selection and design, and production process control.

The study of cooling control system of the CT bulb tube intelligent closed loop / 中国医学装备

Objective:To improve the CT bulb tube cooling rate and the testing method of the CT bulb tube temperature, and provide more stable platform for better bulb tube protection and longer life-span. Methods: The designed specified cold air machine could transfer the dry cold wind into machine rack, which can lower the ambient temperature of the machine rack and increase the air flow inside the machine rack and promote the efficiency of the heat exchange of the bulb tube oil cooling circuit. Results:the design of this system’s joint is light and handy, which could collect the instantaneous temperature change of the bulb tube, and carry out simple man-machine interaction monitoring. Conclusion:According to the bulb tube oil-way temperature and ambient temperature and relative humidity, the computer can dynamically adjust the refrigerating capacity and operation/cease of the air cooler. Then it can constitute the closed control loop, and accelerate the efficiency of the bulb tube’s heat dissipation, and promote the heat capacity of the bulb tube equivalently.

In vitro study on exothermic reaction of polymer-based provisional crown and fixed partial denture materials measured by differential scanning calorimetry / 대한치과보철학회지

STATEMENT OF PROBLEMS: The heat produced during polymerization of polymer-based provisional materials may cause thermal damage to the vital pulp. PURPOSE: This study was performed to evaluate the exotherm reaction of the polymerbased provisional materials during polymerization by differential scanning calorimetry and to compare the temperature changes of different types of resins. MATERIAL AND METHODS: Three dimethacrylate-based materials (Protemp 3 Garant, Luxatemp Plus, Luxatemp Fluorescence) and five monomethacrylate-based material (Snap, Alike, Unifast TRAD, Duralay, Jet) were selected. Temperature changes of polymer-based provisional materials during polymerization in this study were evaluated by D.S.C Q-1000 (TA Instrument, Wilmington, DE, USA). The following three measurements were determined from the temperature versus time plot: (1) peak temperature, (2) time to reach peak temperature, (3) heat capacity. The data were statistically analyzed using one-way ANOVA and multiple comparison Bonferroni test at the significance level of 0.05. RESULTS: The mean peak temperature was 39.5 degrees C (+/- 1.0). The peak temperature of the polymer-based provisional materials decreased in the following order: Duralay > Unifast TRAD, Alike > Jet > Luxatemp Plus, Protemp 3 Garant, Snap, Luxatemp Fluorescence. The mean time to reach peak temperature was 95.95 sec (+/- 64.0). The mean time to reach peak temperature of the polymer-based provisional materials decreased in the following order: Snap, Jet > Duralay > Alike > Unifast TRAD > Luxatemp Plus, Protemp 3 Garant, Luxatemp Fluorescence. The mean heat capacity was 287.2 J/g (+/- 107.68). The heat capacity of the polymer-based provisional materials decreased in the following order: Duralay > TRAD, Jet, Alike > Snap, Luxatemp Fluorescence, Protemp 3 Garant, Luxatemp Plus. CONCLUSION: The heat capacity of materials, determined by D.S.C., is a factor in determining the thermal insulating properties of restorative materials. The peak temperature of PMMA was significantly higher than others (PEMA, dimethacrylate). No significant differences were found among PEMA (Snap) and dimethacrylate (P > 0.05). The time to reach peak temperature was greatest with PEMA, followed by PMMA and dimethacrylate. The heat capacity of PMMA was significantly higher than others (PEMA, dimethacrylate). No significant differences were found among PEMA and dimethacrylate (P>0.05).

Evaluación de lss pérdidas térmicas en calorimería isoperibólica. importancia de los alrededores en la obtención de constantes instrumentales / Evaluation of the thermal leakage in isoperibolic calorimetry. importance of the environs in the obtaining of instrumental constants

Para tres unidades calorimétricas con aislamientos en PVC, nailon y metálico se determina la constante de fugas térmicas, K, con valores de 6,50 x 10-3, 6,37 x 10-5 y 2,52 x 10-4 s-1, respectivamente. Se determina la capacidad calorífica del sistema con agua para cada una de las unidades calorimétricas y se obtienen valores para esta constante de 442,1 J °C-1 para la celda con aislamiento en PVC, 206,7 J °C-1 para la celda con aislamiento de nailon y 408,2 J °C-1 para la celda con aislamiento metálico. Se establece la influencia de la magnitud del efecto térmico en las pérdidas térmicas y en la constante de fugas térmicas, para trabajos eléctricos entre 0,5 y 3,4 kJ. Se determina la entalpía de solución para el sistema propanol-agua, con resultados similares para las tres unidades calorimétricas del orden de 10,7 kJmol-1 .

For three calorimetric units with isolations in PVC, nylon and metal, the heat leakage constant, K, is determined, giving values of 6.50 x10-3, 6.37 x10-5 and 2.52 x 10-4 s-1 respectively. The heat capacity of the system with water for each one of the calorimetric units was determined and values obtained for this constant are of 442.1 JC-1 for the cell with insulation in PVC, 206.7 JC-1 for the cell with insulation of nylon and 408.2 JC-1 for the cell with metallic insulation. The influence of the thermal effect magnitude in the thermal losses and the heat leakage constant, for electrical works between 0.5 and 3.4 kJ is established. Solution enthalpy for the system propanol- water was determined, with similar results for the three calorimetric units of the order of 10.7 kJmol-1.