Bactericidal activity of ozone against Escherichia coli in whole and ground black peppers

The effects of different ozone concentrations and ozonation times on the inactivation of Escherichia coli and on the organoleptic properties of whole and ground black peppers were determined. Black peppers were exposed to three different ozone concentrations (0.1, 0.5, and 1.0 ppm) for different periods (0 to 360 min) at 85% +/- 3% relative humidity (RH) and 25 +/- 0.5 degree C. An approximately 7-log CFU/g reduction of E. coli in whole black peppers was achieved by treating the samples with 0.1, 0.5, or 1.0 ppm of ozone for 360, 240, or 120 min, respectively. E. coli populations in ground black peppers were reduced from an initial count of about 7.5 log CFU/g to 1 log CFU/g after 360 min at 0.1- and 0.5-ppm ozone concentrations, whereas the same microbial reduction was obtained after 240 min at 1.0-ppm ozone concentration. An ozone concentration of 0.1 ppm for 360 min was found to be appropriate to inactivate E. coli in whole and ground black peppers without alteration of the organoleptic properties. No significant differences (P > or = 0.05) were present in the bitterness, flavor, odor, color, or overall acceptability values of the whole and ground black peppers treated with 0.1 ppm of ozone for up to 360 min.     

Synthesis,characterization, biological activity,and thermal stability of new styrenic polymer having pendant ketone and its some derivatives

A new type of styrene monomer, 1‐{4‐[(4‐vinylbenzyl)oxy]phenyl}ethanone (VBOPE), was synthesized. The oxime, phenylhydrazone, toluol‐4‐sulfonic acid hydrazone, and thiosemicarbazone (TSC) derivatives of VBOPE were prepared with hydroxylamine hydrochloride, phenylhydrazine, toluol‐4‐sulfonic acid hydrazine, and TSC hydrochloride, respectively. Radical homopolymerization of the monomers were prepared at 65°C in 1,4‐dioxane solution with benzoylperoxide as an initiator. The compounds was characterized with Fourier transform infrared and NMR techniques. The thermal properties of polymers were investigated with thermogravimetric analysis and differential scanning calorimetry. The activation energies of the thermal degradation of the polymers were calculated with the Ozawa and Kissinger method. The antibacterial and antifungal effects of the monomer and the polymer and its derivatives were also investigated on various bacteria and fungi. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers     

Removal of malachite green by using an invasive marine alga Caulerpa racemosa var. cylindracea

The biosorption of a cationic dye, malachite green oxalate (MG) from aqueous solution onto an invasive marine alga Caulerpa racemosa var. cylindracea (CRC) was investigated at different temperatures (298, 308 and 318 K). The dye adsorption onto CRC was confirmed by FTIR analysis. Equilibrium data were analyzed using Freundlich, Langmuir and Dubinin-Radushkevich (DR) equations. All of the isotherm parameters were calculated. The Freundlich model gave a better conformity than Langmuir equation. The mean free energy values (E) from DR isotherm were also estimated. In order to clarify the sorption kinetic, the fit of pseudo-first-order kinetic model, second-order kinetic model and intraparticle diffusion model were investigated. It was obtained that the biosorption process followed the pseudo-second-order rate kinetics. From thermodynamic studies the free energy changes were found to be -7.078, -9.848 and -10.864 kJ mol(-1) for 298, 308 and 318 K, respectively. This implied the spontaneous nature of biosorption and the type of adsorption as physisorption. Activation energy value for MG sorption (E(a)) was found to be 37.14 kJ mol(-1). It could be also derived that this result supported physisorption as a type of adsorption.     

Self-organization of nanometer periodic structures of clusters in solids

The formation of non-uniform spatial structures in irradiated solids (metals, semiconductors) is investigated, when the subsystem of nonequilibrium lattice defects (vacancies and interstitials) forms bonded states, nanoclusters. A set of kinetic equations is formulated which incorporates, (i) generation of point defects by radiation, (ii) their diffusion and recombination, (iii) mutual pairwise elastic interaction among defects, (iv) formation and growth of the nanoclusters of point defects, and (v) losses of the nanoclusters due to removal from the nucleation zone by diffusion. Linear stability analysis is used to show that, if the temperature (T) of medium is below a critical value (Ter), due to the elastic interaction the homogeneous distribution of point defects and their clusters becomes unstable, and a periodic structure of a nanometer scale arises. The criterion of self-organization of the clusters and the dependence of a super-lattice period on temperature of medium are determined analytically. The critical temperature for self-organization of periodic structures is governed by the dilatation volume of defects, by the potential energy of elastic interaction, and the concentration of defects. Estimations showed that the period of super-lattices may change in the range of (20-80) nm. Obtained results agree with the experimental data.     

Seal bond characterization of laminated plastic food cups by scanning electron and optic microscopes

Heat seals of laminated semi‐rigid food cups were evaluated to characterize the seal bond. Laminated lidding material was sealed at temperatures of 160–180°C to thermoformed cups. Various seal regions of the cups with different ultrasonic signal strengths (%) were sectioned at the rim and examined using optical and scanning electron microscopes (SEM). Ultrasonic signals were able to pinpoint seal defects; however, the magnitude of the signals did not relate to the actual seal condition or seal quality affected by the sealing process. This was attributed to the very short seal width and non‐parallel surface of the heat seal, which possibly resulted in signal loss by reflection and scattering from the seal surface. C‐scan of ultrasound, SEM and optical microscopic images provided the information that the heat‐sealing process was unstable, due to insufficient and non‐uniform heat‐seal temperature or pressure, misalignment of the sealing jaws or non‐parallel sealing or cutting unit configuration. Copyright © 2004 John Wiley & Sons, Ltd.     

Emissions estimation for lignite-fired power plants in Turkey

The major gaseous emissions (e.g. sulfur dioxides, nitrogen oxides, carbon dioxide, and carbon monoxide), some various organic emissions (e.g. benzene, toluene and xylenes) and some trace metals (e.g. arsenic, cobalt, chromium, manganese and nickel) generated from lignite-fired power plants in Turkey are estimated. The estimations are made separately for each one of the thirteen plants that produced electricity in 2007, because the lignite-fired thermal plants in Turkey are installed near the regions where the lignite is mined, and characteristics and composition of lignite used in each power plant are quite different from a region to another. Emission factors methodology is used for the estimations. The emission factors obtained from well-known literature are then modified depending on local moisture content of lignite. Emission rates and specific emissions (per MWh) of the pollutants from the plants having no electrostatic precipitators and flue -gas desulfurization systems are found to be higher than emissions from the plants having electrostatic precipitators and flue -gas desulfurization systems. Finally a projection for the future emissions due to lignite-based power plants is given. Predicted demand for the increasing generation capacity based on the lignite-fired thermal power plant, from 2008 to 2017 is around 30%.