The function of lactic acid bacteria and brine solutions on biogenic amine formation by foodborne pathogens in trout fillets

The influences of lactic acid bacteria and brine solutions on the biogenic amine formation by Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Enterococus faecalis, Pseudomonas aeruginosa, Listeria monocytogenes, Aeromonas hydrophila and Salmonella paratyphi A in fermented trout fillets were investigated. Fish fillets were divided into four groups, group 1 without any lactic acid bacteria inoculation, group 2 and group 3 with different salt concentration inoculated with lactic acid bacteria and food-borne pathogens, and group 4 inoculated with lactic acid bacteria and food-borne pathogens without a salt solution. The histamine content in trout fillets in group 4 was found to be more than 10 mg/100 g, while the other groups contained less than 7.5 mg/100 g. The highest tyramine production was found for group 1 and group 3, ranging from 3 to 18 mg/100 g. Lactic acid bacteria did not seem to play an important role on biogenic amine production by food borne pathogens, while adding brine solution on fillets has inhibitory effects on some of the biogenic amines.     

Signaling alternatives in a wireless ATM network

The world of wireless telecommunications is rapidly changing. The capabilities of wireless networks are improving at a steady pace. This paper presents two possible protocols for implementing mobility for wireless users in an asynchronous transfer mode (ATM) network. The vision of the authors is of one “wireless ATM telecommunications network” that is capable of supporting a variety of today's applications with room to grow for advanced applications of the future. We first visit database architectures that can support mobility in a wireless ATM network. We then discuss one of two signaling architecture alternatives, the “overlay signaling”, for overlay support of mobile users in the ATM-based wireless telecommunications network. “Overlay signaling” aims at minimizing the modification needed to the existing ATM protocols. We then describe a native “migratory signaling” approach that further integrates wireless and wireline users into one global wireless ATM network at the expense of requiring some modifications to the existing ATM protocols. A performance analysis of the proposed signaling architecture alternatives is also presented. We conclude by pointing out some challenges in merging ATM with wireless telecommunications     

Modeling and solving assembly line design problems by considering human factors with a real‐life application

Ergonomics has been playing an important role in assembly system design (ASD) that contains not only the main assembly line balancing problem but also the subassembly line balancing and assembly layout problem. The ergonomics in ASD has an impact both on productivity and on workers’ health, especially when frequent changes in the product mix occur. In this study, we propose a systematic approach in order to handle ASD, which consists of three subproblems, while considering ergonomic risk factors. The first two subproblems are solved simultaneously using the proposed rule‐based constructive search algorithm, where ergonomic risks are evaluated by OCRA method. Later, layout problem is solved under transportation constraints using local search methods with various neighborhood structures. To provide the applicability and evaluate the performance of the proposed systematic approach, a real‐life case study in a harness manufacturing company is solved and prototype productions are performed.     

Effect of Monovalent Cation Doping on Structural,Magnetic, and Magnetocaloric Properties of Pr<Subscript>0.85</Subscript><Emphasis Type="Italic">A</Emphasis><Subscript>0.15</Subscript>MnO<Subscript>3</Subscript> (A = Ag and K) Manganites

A systematic study on the effect of monovalent cation doping on structural, magnetic, and magnetocaloric properties of Pr_0.85 A _0.15MnO₃ (A = Ag and K) samples synthesized by a sol-gel method has been carried out. The crystal structure and morphology have been worked by X-ray diffraction (XRD) and scanning electron microscopy (SEM) imaging measurements. The XRD results indicate that both samples have orthorhombic structure. Magnetization versus temperature measurements show that our samples display a ferromagnetic-to-paramagnetic phase transition with increasing temperature. The ferromagnetic-to-paramagnetic phase transition temperature (T _C) values were found as 74 and 116 K for Pr_0.85Ag_0.15MnO₃ and Pr_0.85 K _0.15MnO₃, respectively. The magnetic entropy changes were evaluated from isothermal magnetization curves measured at various temperatures near T _C by steps of 4 K. The values of the magnetic entropy change were determined as 0.99 and 1.39 J kg ^?1 K ^?1 for Pr_0.85Ag_0.15MnO₃ and Pr_0.85 K _0.15MnO₃ under external field changes of 10 kOe, respectively.     

Normal electromagnetic flux surfaces with the existence of the visco-modified effect

Journal of Computational Electronics - In this paper, the features of current magnetic and electric flow densities are investigated. Their geometric phases computed through the local anholonomic...     

Optimization of enzymatic methanolysis of soybean oil by response surface methodology

Enzymatic methanolysis of refined soybean oil with methanol was investigated using Rhizomucor miehei lipase, Lipozyme RM IM, in n-hexane for reaction times of 30 min. Response surface methodology (RSM) based on three-level, three-factor (variable) face-centered cube design was used for the optimization of methanolysis. The independent variables that affect the methanolysis reaction conducted in n-hexane are temperature (°C), enzyme/oil weight ratio, and oil/methanol molar ratio. A good quadratic model was obtained for the methyl ester production by multiple regression and backward elimination. A linear relationship was observed between the observed and predicted values (R²−0.9635). The effects of temperature and enzyme amount, which affected methyl ester content of the product (response) positively, were significant (P<0.01). The quadratic term of temperature and the interaction term of enzyme amount with temperature affected the response negatively (P<0.01). The interaction term of enzyme amount with substrate mole ratio had a positive effect on the response (P<0.05). Critical conditions for the response at which methyl ester content of the product was 76.9% were determined to be 50°C, 2.37 methanol/oil mole ratio, and 0.09 enzyme/oil weight ratio.     

Batch and continuous processing of polymer layered organoclay nanocomposites

The generation of nanocomposites upon intercalation and exfoliation of clay tactoids using melt compounding is a difficult process. In this study various polymeric binders were melt compounded with organophilic clay particles using myriad methods, including sonication, batch mixing, and twin screw extrusion. The characterization of the compounded samples employing X‐ray diffraction (XRD) and transmission electron microscopy (TEM) revealed that there is little intercalation and exfoliation when nonpolar poly(dimethyl siloxane) (PDMS) and poly(propylene) (PP) binders were used, resulting in no significant changes in the dynamic properties of the suspensions upon small‐amplitude oscillatory shearing. On the other hand, when polar polymeric binders, i.e., silanol terminated poly(dimethyl siloxane) and maleic anhydride modified PP were used for compounding with organoclays, TEM and XRD revealed intercalation with some partial exfoliation, resulting in increases in the dynamic properties, along with sensitivity to the thermomechanical history during processing. These results reinforce earlier findings, which suggest that the interfacial properties between the organoclays and the polymeric binders need to be tailored properly to enable the generation of nanocomposites of organoclays using melt compounding technologies. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1391–1398, 2007     

GIS-based environmental assessment of wind energy systems for spatial planning: A case study from Western Turkey

Increasing population and life standards causes fossil fuel consumption to increase. Due to this increasing consumption, fossil fuels are being depleted rapidly. In addition to rapid exhaustion, another important problem associated with fossil fuels is that their consumption has major negative impacts on the environment. Therefore, many countries around the world have included renewable energy systems (RES) in their future energy plans so that they can produce reliable and environmentally friendly energy. Parallel to this trend, various RES have been identified and recently integrated into the current energy network of Turkey as well. However, it should be recognized that renewable energy resources are not fully environmentally safe. Different RES are associated with different environmental impacts. In planning the future energy development of a country, evaluation of renewable energy resources potentials together with their associated environmental impacts is critical. The aim of this study is to create a decision support system for site selection of wind turbines using Geographic Information System (GIS) tools. Wind energy potential and environmental fitness/acceptability are used as decision criteria for the site selection process. Potential environmental impacts of wind generation are identified in accordance with Turkish legislations and previous studies; and represented as fuzzy objectives of the decision problem. Wind potential map of Turkey generated by General Directorate of Electrical Power Resources Survey and Development is used to identify economically feasible locations in terms of wind energy generation. A study area composed of Usak, Aydin, Denizli, Mugla, and Burdur provinces in Turkey is selected and divided into 250 m × 250 m grids. Each grid represents an alternative location for a wind turbine or group of wind turbines. Fuzzy environmental objectives such as “Acceptable in terms of noise level”, “Acceptable in terms of bird habitat”, “Acceptable in terms of safety and aesthetics” and “Safe in terms of natural reserves” associated with wind turbines are identified based on previous research and each of these objectives are represented by a fuzzy set. Individual satisfaction degree of each of these environmental objectives for each grid is calculated. Then these individual satisfactions are aggregated into an overall satisfaction degree using various aggregator operators such as “and”, “or”, and “order weighted averaging.” Thus, an overall satisfaction degree of all the environmental objectives is obtained for each grid in the study area. A map of environmental fitness is developed in GIS environment by using these overall satisfaction degrees. Then this map is utilized together with the wind potential map of Turkey to identify both potentially and environmentally feasible wind turbine locations within the study area.     

Physical and Oxidative Stabilization of Omega-3 Fatty Acids in Surimi Gels

ABSTRACT: The objective of the study was to compare the dispersion and oxidative stability of omega-3 fatty acid oil in high- and low-quality surimi gels during 4-mo refrigerated and frozen storage. Low-quality surimi was prepared by subjecting Alaska pollock surimi to 7 freeze–thaw cycles. Surimi gels were prepared with 4% modified starch, 2% salt, and 0.5% or 1% algal DHA or concentrated fish EPA-DHA oil, and stored at −18 or 3 °C for 4 mo after being vacuumed packed and pasteurized. The effect of surimi gel properties on oil dispersion was examined using light microscopy equipped with image process software. The extent of lipid oxidation was monitored by thiobarbituric acid reactive substances (TBARS), peroxide value (PV), and fatty acid methly esters (DHA and EPA). Very fine and uniform oil dispersion was observed in the high-quality surimi gel with the average droplet size of 12.37 μm² and dispersion of 1.73 × 10⁻³ droplets/μm² compared to 84.32 μm² and 0.57 × 10⁻³ droplets/μm² in the low-quality gel. Throughout the 4 mo storage, TBARS and PV of high-quality surimi gel were significantly (P < 0.05) lower than those of low-quality surimi gel. The decreases in omega-3 fatty acids in the high-quality surimi gels were lower than those in the low-quality surimi gels under both storage conditions. Results confirm that a highly cohesive gel matrix is required to have a fine dispersion and oxidative stability of omega-3 fatty acids in the surimi gel system. Practical Application: Uniform dispersion and oxidative stability of omega-3 fatty acid oil can be achieved in the highly cohesive surimi gel system without use of antioxidants. This suggests that surimi can be used as a protein-based carrier in developing high omega-3 fatty acids-containing seafood products.     

Thermal Oxidation Kinetics of Refined Hazelnut Oil

In this study, oxidation kinetics of refined hazelnut oil heated at the temperature range from 80 to 180 °C was evaluated. The changes in peroxide value, p‐anisidine value, polymer triglyceride content, α‐tocopherol content, and color values during oxidation were best fitted to zero‐order kinetic model. The rate constants for the p‐anisidine value, polymer triglyceride content, and degradation of α‐tocopherol of hazelnut oil increased at the temperatures between 80 and 160 °C, while the rate constant for peroxide value decreased at the temperatures between 80 and 140 °C. The activation energies for the formation of peroxides (at 80–140 °C), secondary oxidation products such as alkenals, the polymer triglycerides, and degradation of α‐tocopherol were found as 47.49, 29.95, 52.65, and 14.22 kJ mol^?1, respectively. The induction period of hazelnut oil was observed to reduce with increasing oxidation times. The increase in the b* value with the oxidation time and temperature was attributed to the fact that the heating process intensified the yellow color of the oil.