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An investigation on formation of the Ti 2 Al(C,N) solid solution with a broad range of substitutional proportion was performed by solid state combustion in the SHS mode. Metal nitrides, BN and TiN, were adopted as the solid source of nitrogen in the Ti–Al–C combustion system. On account of complete participation of BN in combustion, the BN-added sample is more exothermic than that adopting TiN which imposes a dilution effect on combustion. As a result, the combustion temperature and reaction front velocity are higher for the samples containing BN than TiN. Due to fully-sustainable combustibility, the BN-adopted samples were shown to produce TiB 2 /Ti 2 Al(C 1− x N x ) solid solution composites with x =0.2−0.8 and a TiB 2 /Ti 2 AlN composite from the sample free of carbon. However, the combustibility range of the TiN-added sample was constrained by lack of sufficient reaction exothermicity. Although the Ti 2 Al(C,N) solid solution was also produced from the TiN-adopted sample, the degree of substitution in the Ti 2 Al(C 1− y N y ) phase was confined to y ≤0.5. [ABSTRACT FROM AUTHOR]

Preparation of the Ti 2 (Al,Sn)C solid solution with a broad substitutional proportion was conducted by combustion synthesis of TiC- and Al 4 C 3 -containing powder compacts. Experimental results showed that due to the dilution effect of TiC, relatively low combustion temperatures of about 1090 °C and reaction front velocities of around 2.4 mm/s were obtained for the TiC-added samples. As a result of containing larger amounts of Ti and carbon, the Al 4 C 3 -adopted samples were more energetic than the TiC-added samples. However, the high combustion temperature (1220–1450 °C) and rapid flame speed (6.13–13.87 mm/s) associated with the Al 4 C 3 -added sample were found to be unfavorable for the formation of Ti 2 (Al,Sn)C because probably of insufficient reaction time. On the contrary, Ti 2 (Al 1– x Sn x )C solid solutions with x =0.2–0.8 were successfully produced from the TiC-adopted sample. The synthesized Ti 2 (Al,Sn)C grains exhibited a plate-like morphology and formed a laminated microstructure. [ABSTRACT FROM AUTHOR]

Abstract: This study introduced a novel method using a modified helium gas closed cycle cryogenic system to measure the force acting on a C-shaped magnet by a YBCO superconductor with bias current as a function of temperature. The results showed that the measured force agrees with Lorentz force due to the bias current for normal conductor at temperature higher than the superconducting transition temperature, as expected. However, under a temperature at the beginning of the superconducting transition region, the measured force became larger than the expected Lorentz force. As temperature further decreased, the measured force gradually dropped to zero. A qualitative argument based on the Bean’s model was given to explain the peak in the measured force at the beginning of the transition temperature. [Copyright &y& Elsevier]

Chitosan (CTS) microspheres were prepared by a spray drying method using type-A gelatin and ethylene oxide–propylene oxide block copolymer as modifiers. Surface morphological characteristics and surface charges of prepared microspheres were investigated by using scanning electron microscopy (SEM) and microelectrophoresis. The particle shape, size and surface morphology of microspheres were significantly affected by the concentration of gelatin. Betamethasone disodium phosphate (BTM)-loaded microspheres demonstrated good drug stability (less 1% hydrolysis product), high entrapped efficiency (95%) and positive surface charge (37.5 mV). The in vitro drug release from the microspheres was related to gelatin content. Microspheres containing gelatin/CTS 0.4∼0.6(w/w) had a prolong release pattern for 12 h. These formulation factors were correlated to particulate characteristics for optimizing BTM microspheres in pulmonary delivery. [Copyright &y& Elsevier]