Estimation of the Thermal Diffusivity of Beans Using a Simple Apparatus

A simple apparatus for the determination of the thermal diffusivity of black-eyed beans samples, using the transient heat conduction method is presented. This apparatus is a stainless steel cylindrical tube, containing the sample, placed into a constant temperature water bath. The variation of the temperature at the center of the tube with time is recorded. The thermal diffusivities were determined from the temperature-time relationship data of the sample, and the dimensions of the equipment. The estimated thermal diffusivity values of the samples varied between 4.70 x 10-8 to 6.94 x 10-8 and 5.26 x 10-8 to 7.68 x 10-8 when the temperature in the water bath was 50oC and 60oC, respectively. Also, the thermal diffusivity was higher when the water bath temperature was 60oC rather than 50oC for the sample range of particle sizes studied. As black-eyed beans are a staple food in many parts of West African, they are grown, harvested, and stored. The thermal diffusivity information is useful in determining the behaviour of this Argo-product when stored. Keywords: Beans, Thermal Diffusivity, Transient Heat Conduction Method.

Influence of composition on the structure and properties of SrO–Sb2O3–P2O5 low-melting sealing glasses

SrO–Sb2O3–P2O5 glass system was prepared by high temperature melting method. The effects of Sb2O3 and P2O5 content on the structure, thermal behavior and chemical durability of the glasses were studied by infrared spectrometer, thermal dilatometer, differential thermal analyzer and constant temperature water bath heating. It can be concluded that the characteristic temperatures of the glasses increased firstly and then decreased with the increasing of Sb2O3 content, whereas the tendency of the coefficient of thermal expansion (CTE) varied inversely. The crystallization ability of the glasses was significantly increased and the water resistance was reduced for Sb2O3 content of 35 mol % and 40 mol %. The glasses with 20 mol %, 25 mol % and 30 mol % Sb2O3 showed better performance in every respect than the others and the glasses containing 25 mol % Sb2O3, characterized by the best performance, can be chosen as host glasses for further research.

Research of Artificial Rumen Constant Temperature Water Bath Based on Fuzzy Logic Controller

In the artificial rumen device constant temperature water bath temperature control for model and parameter uncertainty is proposed that 89S51 microcontroller as the control core, using fuzzy control algorithm, realized thermostatically control of water bath temperature. This paper presents the overall system architecture and design philosophy of fuzzy control unit and associated circuits. Systematic simulation and test operation showed that: the good dynamic responses of the system, high precision control, strong robustness, achieve better control of the water bath temperature.

Background Leakage of Pressure Leak Calibration Caused by Temperature Change

On laboratory conditions，background leakage caused by temperature change was one of the most important factors for affecting calibration of pressure leak, consequently, the constant temperature water bath of the calibration apparatus has been used to reduce background leakage by means of keeping the apparatus temperature constant. The method of active and passiveness were combined to keep constant temperature. through the research on experimentation, it was found that background leakage was decreased to the grade of 1.36×10-9Pam3/s when constant temperature been used, and meanwhile the lower limiting of pressure leak was extended to 2.667×10-8Pam3/s.

Simultaneous Measurement of Temperature and Velocity Using µPIV

In μPIV, for a uniform velocity field the displacement of the cross-correlation function gives the velocity of the fluid and the broadening of the peak-width represents the amount of Brownian motion present. In the presence of a linear or a parabolic shear, the shape of the cross-correlation function would have both the Brownian motion information as well as the velocity distribution information. In the present work, the broadening of the cross-correlation function caused by the velocity gradient was subtracted from the total peak broadening in order to isolate the Brownian motion information and thus infer temperature. To the authors' knowledge, this technique has not been applied to measure the temperature of a moving fluid. The experiments were conducted in a gravity driven flow through a tube surrounded by a constant temperature water bath.

Thermal Resistance of Spores from Five Type E Clostridium botulinum Strains in Eastern Oyster Homogenates

The thermal resistance of spores from five type E Clostridium botulinum strains, Alaska, Minnesota, G21-5, 25V-1 and 25V-2, in oyster homogenates was determined at 73.9, 76.7, 79.4, and 82.2°C. Thermal death times (TDT) were determined in TDT tubes containing 1-g sample and heated using a constant temperature water bath for different time intervals. D values ranged from 0.07 to 0.43 min at 82.2°C (180°F) and from 2.00 to 8.96 min at 73.9°C (165°F). One strain (Minnesota) isolated from a botulism outbreak in Minnesota was the most heat resistant while strains isolated from crabs (G21-5, 25V-1, and 25V-2) were least resistant. The z values were 4.2 to 5.4°C for strain (Alaska) associated with an outbreak and 6.0 to 7.1°C for the other four strains. Results indicate that these organisms are less heat resistant in oyster homogenate than other seafood products. However, current oyster pasteurization methods are not sufficient to guarantee safety from type E. C. botulinum spores, and further studies are needed to assure product safety.