The thermal stability of enzyme-based biosensors is crucial in economic feasibility. In this study, thermal deactivation profiles of catalase Aspergillus niger were obtained at different temperatures in the range of 35° C to 70° C. It has been shown that the thermal deactivation of catalase Aspergillus niger follows the first-order model. The half-life time t 1/2 of catalase Aspergillus niger at pH 7.0 and the temperature of 35° C and 70° C were 197 h and 1.3 h respectively. Additionally, t 1/2 of catalase Aspergillus niger at the temperature of 5° C was calculated 58 months. Thermodynamic parameters the change in enthalpy ΔH*, the change in entropy ΔS* and the change Gibbs free energy ΔG* for the deactivation of catalase at different temperatures in the range of 35° C to 70° C were estimated. Catalase Aspergillus niger is predisposed to be used in biosensors by thermodynamics parameters obtained.
The release of phenol-containing effluents above the phenol permissible limit has triggered a lot of concern over the world due to their toxic nature. The adsorptive potential of gypsum on the removal of phenol was investigated. The effect of gypsum loading (0.5–3 g), contact time (2.5–20 min) and solution temperature (298 to 318 K) on the removal of phenol by gypsum was studied at neutral pH. The thermodynamics of the adsorption process was also studied. The kinetic data were fitted into the pseudo-second-order, Elovich, and intraparticle diffusion models. The removal efficiency of phenol increased along with the mass of gypsum, contact time and temperature. The results of the thermodynamics study indicate that the adsorption process is spontaneous and endothermic in nature. The change in free energy (ΔG0) was found to increase with temperature. The values of the estimated ΔG0 suggest that the phenol adsorption on gypsum is a physical adsorption process. Additionally, the kinetic data fitted best into the pseudo-second-order than the other kinetic models. This study proved that phenol can be used effectively for the reduction of phenol concentrations in water and wastewater.
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Tuning silnika spalinowego jest to zbiór działań modernizacyjnych, prowadzących do poprawy jego sprawności. W praktyce warsztatowej prace tuningowe są wykonywane często w oparciu o technikę „prób i błędów", co oczywiście wydłuża czas modernizacji, podraża koszty, a czasami prowadzi do błędnych rozwiązań. Współczesna praktyka inżynierska nakazuje, aby projektowanie zmian tuningowych silników spalinowych wspomóc komputerowo. Umożliwia to prowadzenie obliczeń na szeroką skalą - z wykorzystaniem wielu modeli, stworzeniem dużej ilości wariantów rozwiązań i wyborem najkorzystniejszego spośród nich - zanim zostaną wykonane jakiekolwiek prace na obiekcie rzeczywistym. W niniejszej pracy przedstawiono przykładowa komputerowo wspomaganą analizę cieplnych i wytrzymałościowych parametrów silnika spalinowego poddanego zabiegom tuningowym.
EN
Tuning of internal combustion engine means modernization to improve its efficiency. In service often tuning is made "do and look". Each tuning operation needs energetic and thermal analyses. The garage service teams make often tuning follow the technique "do and then look". It takes time, money and sometimes gives mistakes. Nowadays Computer Aided Engineering technology can be employed to make tuning. There are many possibilities to check and change some parameters of engine work looking for the best solution. It is necessary to develop CAE for timing engine to give quick and right answers for automotive engineers - especially involved in car racing.
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