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The aim of this study is to evaluate the biodegradable packaging materials which will be an alternative to traditional synthetic packaging materials. For this purpose, packaging films containing polycaprolactone (PCL), montmorillonite (MMT), and organically modified montmorillonite (OMMT) were prepared by solution casting method, and the mechanical, physical, structural, antimicrobial, and antifungal properties of these films were examined. Cetyl trimethyl ammonium bromide (CTAB) was used for the modification of montmorillonite. The structural properties of the prepared films were characterized by attenuated total reflection-Fourier transform infrared, X-ray powder diffraction, thermogravimetric analysis, and scanning electron microscopy. The PCL/OMMT structure was found to be thermally more stable than the PCL/MMT structure. The addition of OMMT to PCL improved the thermal and mechanical properties of the films compared with the pure PCL and PCL/MMT films. In addition, adding MMT/OMMT to the PCL caused an increase in the hardness of the films. In the antimicrobial analysis, while no inhibition effect was observed in PCL/MMT films, PCL/OMMT films showed inhibition effect against Staphylococcus aureus. Antifungal tests performed with the prepared films showed that the film-wrapped bread did not deteriorate for 40 days. It is thought that PCL/MMT and PCL/OMMT films prepared in this study will provide an advantage in applications as packaging material.

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The lignocellulosic hydrolysates provide a rich medium for fermentation of sugars into ethanol. The potential use of sunflower seed hull hemicellulose hydrolysate in ethanol fermentation was evaluated by using the Experimental Design method in this study. A 2 2 Box-Wilson experimental design was used to develop a statistical model. The effects of shaking rate (55-145 rpm) and initial pH (4.6-7.4) on the fermentation of hydrolysate with Pichia stipitis yeast were studied in shaking bath experiments at 30C. Model equations that represent maximum ethanol concentration E max and ethanol yield Y P=S in terms of shaking rate and pH were developed by using the Design-Expert package program. From response surfaces, optimum variables were calculated numerically by the Design-Expert computer program. Such a procedure provided the optimum values of the parameters with respect to both Y P=S and E max as X 1 ¼ 5.89 pH and X 2 ¼ 114.6 rpm. The maximum ethanol concentration of 11.04 g=L and ethanol yield of 0.32 were obtained with these optimized parameters.

The axial and radial effective thermal conductivities of a monolithic ceramic catalyst support and of porous alumina pellets were measured using the moment technique. At 180 °C, radial and axial thermal diffusivities were determined as 9.3 x 10-3 and 11.1 x 10~3 cm2is-1, respectively. Having pores being filled with hydrogen, the corresponding thermal conductivity values are 0.43 and 0.52 Wm_1'K_1, respectively. Experimental results obtained between 110 and 180 °C indicated a negligibly small dependence of effective thermal conductivities on temperature. A proposed model which included the geometrical parameters of the monolith and the thermal conductivity ratio of the ceramic catalyst support to gas was shown to give excellent agreement with experimental results. Thermal conductivities of alumina pellets having bidisperse pore structures were also measured using this dynamic procedure. Experimental effective thermal conductivity values ranged between 0.043 and 0.120 W-m^K"1 for pellets having porosities between 0.79 and 0.57, respectively.

Abstract:In this study, the combined effects of initial dye (40-700 mg/L) and initial reducing sugar concentration (1-15 g/L) on the bioaccumulation of Violet 90 metal-complex dye by growing cells of Candida tropicalis yeast were investigated in growth media containing sugar beet molasses as a carbon and energy source. The bioaccumulation experiments were performed at pH 3 at 30• C and at 140 rpm agitation rate in a batch system. The highest uptake was obtained as 61.46% at 14.9 g/L reducing sugar concentration and at 38 mg/L dye concentration while the maximum uptake capacity was achieved as 56.28 mg/g at 3.2 g/L reducing sugar concentration and at 711.1 mg/L dye concentration. Higher uptakes were obtained at lower dye concentrations; higher uptake capacities were observed at higher initial dye concentrations.The combined effects of the initial dye (100-500 mg/L) and initial reducing sugar concentration (5-15 g/L) on dye uptake capacity and growth rate of Candida tropicalis yeast were also investigated by response surface methodology (RSM).Optimum design variables from RSM were calculated by numerical optimization with the Design Expert program. The optimum values of the variables to maximize uptake capacity were estimated as 5.1 g/L reducing sugar concentration and 499 mg/L dye concentration. The maximum uptake capacity was achieved as 41.3 mg/g at these optimized conditions.

The use of clinoptilolites of Western Anatolia in detergents as phosphate substitutes was investigated. The cations present in the clinoptilolite samples were first exchanged with sodium ions. The washing characteristics of detergent mixtures containing surfactants, clinoptilolite, sodium carbonate and sodium sulphate were analysed. The stains of coffee, tea and tomato paste were tested. The washing tests were repeated for different surfactants, i.e. linear alkyl benzene sulphonate, sodium alkyl sulphate and alcohol ethoxylate and for different co-builders, i.e. sodium carbonate and EDTA. In addition, the effects of detergent dose and detergent formulation on washing were investigated. Other factors affecting the degree of soil removal such as shaking time, temperature and water hardness were also studied. The contribution of clinoptilolite to the washability was compared with zeolite A, zeolite X and sodium tripolyphosphate.Increasing the shaking time and temperature improves the degree of cleaning. LAS was the most effective surfactant for use with clinoptilolite. The washing performance of the detergent mixtures used in the present work was found to be comparable with that of commercial detergents at low washing temperatures.