Investigation of adsorption–desorption dynamism of bovine serum albumin on crosslinked N,N′‐diethylaminoethyl dextran microbeads: Solution phase

New hydrogel microspheres based on crosslinked dextran containing N,N′‐diethylaminoethyl (DEAE) groups with different chemical structures have been used in adsorption–desorption studies. Bovine serum albumin (BSA) is frequently used in biophysical and biochemical studies. BSA has a well‐known primary structure that has been associated with binding of many different categories of small molecules. Both adsorption kinetics and equilibrium isotherms for the adsorption of BSA on crosslinked DEAE dextran have been determined experimentally. These were only slightly dependent on the initial concentration of BSA but were considerably affected by the pH of the medium. The results fitted the Freundlich–Langmuir isotherm model for pH 6.9. The adsorption capacity factor and the adsorption equilibrium constant were obtained and mathematical modeling of adsorption, adsorption rate constants, and maximum adsorption were determined. Swelling kinetics of crosslinked DEAE dextran and optimum ionic strength, pH, and mass of hydrogel were also investigated. Desorption studies were finally determined under optimum medium conditions. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci, 2006     

Removal of phosphate from aqueous solutions by electro-coagulation

The aim of this paper was to investigate the feasibility of the removal of phosphate from aqueous solution by electro-coagulation (EC). The current density (CD) between 2.5 and 10 mA cm(-2) and duration in the limits of 5-20 min were tried for different concentrations. In order to determine optimal operating conditions, the EC process used for the phosphate removal was examined in dependence with the CD, initial concentrations and time. The results of the experimental batch processing showed high effectiveness of the EC method in removing phosphate from aqueous solutions.     

The effects of the combination of freezing and the use of natural antioxidant technology on the quality of frozen sardine fillets (Sardinella aurita)

The effects of combination of freezing and the use of antioxidant technology on the quality of frozen sardine fillets were investigated in terms of sensory, biochemical [thiobarbituric acid (TBA), total volatile basic nitrogen (TVB‐N), peroxide value (PV) and free fatty acids (FFA)] and microbiological analyses [total viable count (TVC)]. Fish were filleted and divided into three groups. The first group was used as the control (C) without rosemary extract, the second group was treated with 1% rosemary extracts for 2 min (R1) and the third was treated with 2% rosemary extracts for 2 min (R2). All groups were frozen at ?18 °C over the storage period of 6 months. The results obtained from this study showed that the combination of antioxidant and frozen storage resulted in significant reduction of bacterial growth and stabilised the biochemical characteristics, especially for R2. However, the use of antioxidant at the level of 2% (R2) gave a bitter taste according to sensory assessment whereas the panellists mostly preferred R1.     

Bond strength of repaired composite resins: surface treatments,adhesive systems,and composite type

The aim of the present study was to investigate the effects of three different surface treatments and two different adhesives on the microtensile bond strength (μTBS) of repaired composites using the same or different type of resin. Twenty-four nano-hybrid (Ceram X mono-C) and 24 nanofilled (Filtek Ultimate-F) composite discs were prepared. The specimens were aged with 5000 thermocycles and randomly divided into groups according to the surface treatment methods: (a) phosphoric acid (b) Er:YAG laser and (c) aluminum trioxide particle (air abrasion). Fresh composite resins (C and F) were added to the treated surfaces with two different adhesives (two-step and one-step self-etch adhesives). Then, the specimens were aged again. The stick-shaped specimens were prepared from the discs (n = 25) and the sticks were subjected to the μTBS test. Results indicated that significant differences were found in μTBS values among the surface treatment methods. In the C groups, the highest μTBS value (41.3 ± 8.3 MPa) was recorded in the air abrasion and one-step self-etch adhesive group, which were repaired with the same kind of composite. In the F groups, the highest μTBS value was observed in the air abrasion and one-step self-etch adhesive (37.6 ± 12.3 MPa) group. The treatment with air abrasion is more effective than the others, and it may be suggested for composite repair.     

Multi-response optimization of thermophysiological comfort properties of polyester filament woven fabrics

Microfilament woven fabrics are used in many products such as sportswear, rainclothes, windproof clothes, sleeping bags and surgical gowns and for these products, thermophysiological comfort properties are of prime importance. In this study, it is intended to investigate the effects of filament linear density and weft sett on thermophysiological comfort properties. Also, an optimization model was developed to determine the optimum filament linear density and weft sett for the best response variables of air permeability, water vapour permeability and thermal resistance. Four different weft sett and five different filament linear densities were applied in weft direction with three different weave types. In doing so, 60 woven fabric samples were produced. According to ANOVA results and experimental observations, it is observed that, the effect of filament linear density on air and water vapour permeability was minor on microfilament range, whereas the differences between conventional filament and microfilament sample groups are considerable. Also, higher weft sett causes decreasing of air and water vapour permeability. On the other hand, there is no obvious consistent trend for thermal resistance of samples with different filament linear density and weft sett.     

Directional double Fano resonances in plasmonic hetero-oligomers

We experimentally demonstrate for the first time a very compact plasmonic hetero-oligomer structure where the multiple radiant and subradiant modes can be tailored independently. Unlike previous approaches based on collective excitations in complex plasmonic systems, we show precise engineering of resonances leading to simultaneous spectral overlap of multiple plasmonic modes with opposite radiative character. This asymmetric behavior combined with inherent spatial features of the structure leads to directional double Fano resonances as shown with numerical analysis. A model based on temporal coupled mode theory is also provided to describe the double Fano behavior.     

Chemometric and phenolic attributes of blended wines assessed by multivariate techniques

The aim of the study was to investigate the quality of blended wines produced from Vitis vinifera L. Cabernet Sauvignon, Merlot and Sauvignon blanc grapes. Wines were processed according to accepted conventional methods for white and red wines. Blended wines were produced with different ranges (25, 50, 75 and 100%) of Cabernet Sauvignon, Merlot and Sauvignon blanc wines. Produced wines were evaluated for total phenols (mg/L), total tartaric esters (mg/L caffeic acid), total flavonols (mg/L quercetin), chemometric parameters such as D280%, D420%, D520%, D620%, dA%, CD%, T, CI%, R%, Y% and B%, CIELAB parameters, protein, total and volatile acidity. Analyses on an n‐dimensional scale demonstrated the relationships among the wines of different grape origins and different blending ratios. On the basis of these differences, two main groups were plotted using principal component analysis and cluster analysis. The results demonstrate the possibilities of optimizing wines on the basis of defined parameters. Copyright © 2015 The Institute of Brewing & Distilling     

Evaluation of methods for DNA extraction from must and wine

The quality of wine depends on many factors. One of the most important is the selection of appropriate and defined grape varieties. The analysis of phenolic compounds, amino acids, trace elements and isotopes of wines, used for the identification of grapes varieties, is not sufficient and requires a lengthy analysis period. The development of molecular techniques such as restriction fragment length polymorphism, random amplified polymorphic DNA and microsatellites provides opportunities for the differentiation of grape varieties. In this regard, the use of DNA extracted from must and wine appears to be a good marker for the identification of grape varieties used in wine production. In this study, DNA was extracted from grape, leaf, must and wine samples of Vitis vinifera L. cv. Cabernet Sauvignon, Merlot and Sauvignon Blanc origin and examined using different extraction methods. Of the DNA extraction methods tested, the method using absorption at 260/280 nm (with values of 0.19 and 1.92) was considered the method of choice. Copyright © 2014 The Institute of Brewing & Distilling     

Electrical properties of polyaniline‐manganese chloride composites

Electrical and morphological properties of Polyaniline (PANI) filled with various mass fractions of manganese chloride (MnCl₂) synthesized in aqueous hydrochloric acid (HCl) medium using ammonium persulphate as an oxidant were investigated. The sample morphology was characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). Significant changes were observed in the morphology of the samples depending on the filler level. The direct current (dc) and alternating current (ac) electrical properties were investigated as a function of temperature. The dc conductivity decreased 72% with 10% filler level whereas ac conductivity has shown a 120% increase with 6% filler level at room temperature. It is shown that the alternating charge transport mechanism of the unfilled and filled polyaniline samples is consistent with correlated barrier hopping (CBH) model. Imaginary (M″) parts of electric modulus exhibited temperature‐dependent dielectric relaxation behavior for both filled and unfilled PANI samples. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers.     

Measuring the Young’s modulus of polystyrene-based composites by tensile test and pulse-echo method

In this study, the pure polystyrenes (PS) with different molecular weights (3.5 × 10⁵ and 5.0 × 10⁵) have been modified by the chemical modification with succinic anhydride (SA), maleic anhydride (MA), and phthalic anhydride (PhA). The modified polystyrenes (MPS) have been mixed with the pure PS with the molecular weight of 2.3 × 10⁵ in weight % ratio 90:10, 80:20, and 70:30. Young’s modulus of obtained composites has been measured mechanically by the tensile test and ultrasonic method at frequency of 5 MHz. Further, the values of Young’s modulus measured by both methods have been compared with each other. From the results, a significant difference has not been found between the values of Young’s modulus of both methods. As a result it can be stated that measuring the Young’s modulus of these materials by the ultrasonic methods is more sensitive and economical than the mechanical methods.