the effects of temperature, time and the strategy of prepolymerization were studied on the morphology of polypropylene particles. propylene polymerization was carried out in slurry phase using 4th generation of ziegler-natta catalyst, cyclohexylmethyl dimethoxysilane as external electron donor, and triethyl aluminum as co-catalyst. prepolymerizations were carried out based on two strategies: is...

Precipitation behavior and the quenching sensitivity of a spray deposited Al-Zn-Mg-Cu-Zr alloy during isothermal heat treatment have been studied systematically. Results demonstrate that both the hardness and the ultimate tensile strength of the studied alloy decreased with the isothermal treatment time at certain temperatures. More notably, the hardness decreases rapidly after the isothermal h...

the present work is the successful extension of an improved equation of state (eos) to refrigerant fluids. the objective is the prediction of isothermal and saturated liquid densities of refrigerants. two temperature-independent parameters appearing in the modified eos are closely related to critical point properties of refrigerant fluids. our results showed that, the proposed eos can predict w...

an analytical equation of state has been previously modified by papari et al. for representing the volumetric properties of molecular fluids. however the performance of that eos has not been yet well investigated for refrigerant fluids. this study extended that equation to 19 liquid refrigerants to predict their densities at isothermal and saturated states. two temperature-independent parameter...

For non-isothermal operation in plate type gas absorber, the temperature changes and number of ideal trays can be determined with recourse to graphical method. In this paper there is an analysis illustrating that a Modified Kremser Equation can be used for plate type gas absorber in non-isothermal operation.

The possibility of producing chemical fuel (hydrogen) from the solar-thermal energy input using an isothermal cycling strategy is explored. The canonical thermochemical reactive oxide, ceria, is reduced under high temperature and inert sweep gas, and in the second step oxidized by H2O at the same temperature. The process takes advantage of the oxygen chemical potential difference between the in...

Isothermal and non-isothermal torrefaction characteristics and kinetics of microalga Scenedesmus obliquus (S. obliquus) CNW-N are studied using thermogravimetric analysis. The pyrolysis of S. obliquus CNW-N with increasing temperature is characterized by four-stage decomposition. Depending on the torrefaction temperature, light, mild, and severe torrefaction from the weight loss and the maximum...