Papers by Keyword: Temperature Cycling

Abstract: Typically, the emollient effect of the vegetable oil has attributed to its usefulness in skin care preparation. The present study aims to prepare the oil in water emulsion cream containing virgin coconut oil (CO) comprisinghydrophilic and lipophilic surfactants (Tween 80 and Span 80). Stability of creams containing CO upon addition of peppermint oil (PO), co-surfactant (Solutol HS 15, ST), solubilizer (benzyl benzoate, BB) was investigated after the temperature cycling. All prepared creams showed the shear thinning flow behavior. Addition of BB gave the lowest viscosity while that comprising ST exhibited the higher viscosity. The highest viscosity formula was the CO andPO containing cream. The particle size determined using light scattering particle analyzer revealed that the mean particle size of all prepared creamswaslower than 35.56 ± 0.62 µm. The homogenous dispersion of oil globules in emulsion was evident, especially, in formulation II (CO) and IV (COand ST). Although the temperature cycling influenced more or less on the compact structure of gel network of cream, the decrement of viscositywasminimal and not much different for cream containing CO and ST (formulation IV). In addition, the mean particle size wasthe smallest for formulation II (CO) which was followed by formulation IV (CO and ST). There wasthe homogenous dispersion of oil globules in formulation II and IV after temperature cycling. All of the above finding was beneficial for employingCO as the oil phase in producing cream such as the foot massage cream where the addition of ST provided the better stability for the prepared cream containing CO.

Abstract: This paper mainly studies the effect of temperature cycling on stress relaxation behavior of contacts for electrical connectors. Based on the analysis of the test specifications of electrical connectors, this paper provides a kind of test method on stress relaxation behavior of electrical connector contacts under temperature cycling conditions. The detecting circuit is designed; the test is carried out and finally, according to the test data, it can be concluded that 1) for the same temperature change, the absolute change of strain within the temperatures above zero is bigger than that within the subzero temperatures; 2) the deformation of contacts gradually increases as the number of cycles increases. The length of the degradation process for electrical connectors might be related with the high temperature value, temperature variation or temperature variation rate.

Abstract: A fully electrically isolated package for a SiC temperature sensor, able to work at high temperature, is presented in this paper. The adopted packaging solution was tested under thermal stress by varying the temperature between 300C and 400C (for 500 cycles) and between 50C and 400C (for other 500 cycles). The thermal stress had negligible effect on the capsules leakage currents (measured from the sensor terminals to the package metal casing) and did not degrade the glass which ensures the sealing of the capsule. The measurements and microphysical investigations showed a stable operation of the package up to temperatures of 400C.