Study on thermal decomposition kinetics of azobenzene-4,4′-dicarboxylic acid by using compensation parameter method and nonlinear fitting evaluation

Recently,azobenzene-4,4'-dicarboxylic acid(ADCA)has been produced gradually for use as an organic synthesis or pharmaceutical intermediate due to its eminent performance.With large quantities put into application in the future,the thermal stability of this substance during storage,transportation,and use will become quite important.Thus,in this work,the thermal decomposition behavior,thermal decomposition kinetics,and thermal hazard of ADCA were investigated.Experiments were conducted by using a SENSYS evo DSC device.A combination of differential iso-conversion method,compensation parameter method,and nonlinear fitting evaluation were also used to analyze thermal kinetics and mechanism of ADCA decomposition.The results show that when conversion rate α increases,the activation energies of ADCA's first and main decomposition peaks fall.The amount of heat released during decomposition varies between 182.46 and 231.16 J·g^(-1).The proposed kinetic equation is based on the Avrami-Erofeev model,which is consistent with the decomposition progress.Applying the Frank-Kamenetskii model,a calculated self-accelerating decomposition temperature of 287.0℃is obtained.

Thermal evaluation of the injectable liquid metal bone cement in orthopedic treatment

The thermophysical properties of bone cement are important parameters for its application in the orthopedic treatment. This article focused on the thermal evaluation of the low-melting-point metal(Bi In Sn alloy), which has been proved to be an excellent bone cement. Firstly, the basic thermophysical properties of Bi In Sn alloys with different melting points were measured.Secondly, 15 fresh porcine femurs placed in the saline bath, bone cements with different melting points and amounts were injected into the bone cavities, respectively. Thermocouples were used to measure the temperature changes of the bone-cement interface and peripheral bone tissue. The possibility of thermal necrosis was evaluated. Moreover, a three-dimensional human knee model was built to numerically assess the effects of thermal parameters, such as melting point and latent heat on tissue temperature distribution. All the experimental and numerical results implied the heat distribution in the tissue depended on the thermal performances of liquid metal bone cement(LMBC). For LMBC of the same melting point, with increased amounts, the damage to the bone tissue is more severe, while for the same amount of different melting point LMBCs, with the higher melting point, which will lead to more serious damage to the tissue. Also, higher latent heat of LMBC has distinct longer solidification process, which may cause irreversible damage to surrounding tissues. Therefore, in the future, for different clinical surgery needs, the appropriate liquid metal bone cement can be obtained by adjusting the thermal parameters.

Energy Consumption and Thermal Performance in Different Residential Building Types in Hot-Summer and Cold-Winter Zone

In China, REC （residential energy consumption） is the second largest energy use category （10%） following the industry. To fulfill the Chinese government＇s commitment that Chinese CO2 emissions would peak in 2030, as a result, improving the energy efficiency and reducing the emissions from the building sector is significantly important. A survey, in the form of a questionnaire, of energy consumption and thermal situation in different residential building types （detached house, multi-story building, high-rise building）, was undertaken in three cities （Shanghai, Hangzhou, and Changzhou） in hot-summer and cold-winter regions, these three cities were selected to represent the most flourishing economic provinces. This region in China was selected for the evaluation of EETP （energy and thermal performance analysis）, because of its special weather conditions, huge energy consumption （as both heating in winter and cooling in summer are necessary）, and other regional characteristics. 183 households were sampled and experiments were separately done in typical examples of three different building types. Systematic evaluation on EETP for three different residential building types, were put forward to assess the energy efficiency and thermal performance of three different building types.