The effect of core-sheath proportion on the characteristics of fabrics produced with hollow yarns: part II comfort and mechanical properties

The study aims to investigate the effect of hollow yarn structure and the sheath-core proportion of hollow yarns on the permeability properties of the knitted fabrics. In order to accomplish this, core yarns in the yarn count of 59 tex were produced by using cotton, viscose, wool, and polyester fibers in the sheath and different ratios of polyvinyl alcohol (PVA) in the core. After completion of yarn production on ring spinning frame, the yarns in the form of packages were used to produce plain knitted fabrics. Fabrics were then divided into two groups, one of which was washed during a time period in order to remove PVA from the core to obtain hollow yarn structure. Air and water permeability, and wicking properties of the knitted fabrics were measured before and after washing processes. Mechanical properties such as pilling and bursting strength of the fabrics were also examined. The results show that washing process and PVA proportion used to produce core spun yarns have a significant effect on the permeability and mechanical properties of the fabrics.     

The production of fuel from,and the thermal stability of,sunflower oil,corn oil,and canola oil

Frying of sunflower, corn, and canola oils was carried out for seven running days at 175°C in this study. Fatty acid composition, free fatty acid, viscosity, iodine value, peroxide value, density, pH, saponification value, refractive index, average molecular weight, color, and the higher heating value of these oils have been analyzed. While the contents of free fatty acid, viscosity, saponification value, peroxide value, and colors (red and yellow) increase with the frying times, the contents of average molecular weight, iodine value, pH, and the higher heating value decreased for all oils in this work. However, reduction in the higher heating value is relatively low. This work indicated that recycling as a fuel of these oils can make a major economic contribution.     

Force analysis of bearings on a modified mechanism using proposed recurrent hybrid neural networks

Due to different load conditions on four-bar mechanisms, it is necessary to analyze force distribution on the bearing systems of mechanisms. A proposed neural network was developed and designed to analyze force distribution on the bearings of a four bar mechanism. The proposed neural network has three layers: input layer, output layer and hidden layer. The hidden layer consists of a recurrent structure to keep dynamic memory for later use. The mechanism is an extended version of a four-bar mechanism. Two elements, spring and viscous, are employed to overcome big force problem on the bearings of the mechanism. The results of the proposed neural network give superior performance for analyzing the forces on the bearings of the four-bar mechanism undergoing big forces and high repetitive motion tracking. This continuation of simulation analysis of bearings should be a benefit to bearing designers and researchers of such mechanisms.     

Estimation of strength and deformation properties of Quaternary caliche deposits

The aim of this study was to develop and evaluate statistical models for predicting the uniaxial compressive strength (UCS) and average Young’s modulus (E _av) for caliches, using some index and physical properties. The caliche samples, from Adana, southern Turkey, were of low strength and difficult to sample. X-ray diffraction and microscopy were undertaken and the following physical parameters established: unit weight, apparent porosity, Schmidt rebound number, Shore hardness, P-wave velocity, slake durability, point load, uniaxial compressive strength and average Young’s modulus. Simple and linear regression variable selection analyses were performed. The best relationships were obtained for UCS with P-wave velocity and unit weight and for average Young’s modulus with P-wave velocity, porosity and slake durability. Empirical equations are proposed, although it is emphasised that these may only be applicable for caliche of a similar geological character.      

Whey protein nanoparticles prepared with desolvation with ethanol: Characterization,thermal stability and interfacial behavior

Whey protein isolate (WPI) nanoparticles were prepared by diluting an alkaline solution of protein in ethanol at concentrations varying between 50 and 80%. The nanoparticles were then immediately diluted in buffer. While the nanoparticles were not stable at pH 7, they showed no changes in size when diluted at pH 3. When 75–80% ethanol was added during preparation, the size of the WPI nanoparticles ranged between 10 and 100 nm, with no change in size after dilution and storage at pH 3 for 96 h at 22 °C. When heating was applied, particle aggregation occurred, and large aggregates (>1 μm) were observed at temperatures > 60 °C. The particle size of the heat-induced aggregates could be reduced by homogenization. The nanoparticles prepared by desolvation showed interfacial pressure values similar to those of the corresponding protein solutions, indicating similar interfacial properties and the potential to be used to stabilize emulsions but as supramolecular aggregates of WPI.     

Molecular characterization of mulberry (Morus spp.) genotypes via RAPD and ISSR

BACKGROUND: In recent years, DNA‐based markers have been used quite extensively because of their many advantages over the traditional morphological and biochemical markers. Many studies have shown that molecular markers are useful in delineating the genetic relationships among closely related mulberry genotypes and cultivars. Thus, in the present study, polymer chain reaction based DNA fingerprinting techniques were used to investigate the genetic relationships among mulberry genotypes growing in different agro‐climatic regions of Turkey. RESULTS: 20 RAPD primers generated a total of 173 bands, of which 157 (90.75%) were polymorphic. As for 11 ISSR primers, 124 bands (96.55%) were polymorphic in a total of 128. The similarity index for RAPD technique ranged between 0.24–0.98; 25?s203 with 25?s112 were found to be the closest genotypes, while 24Ke10 and 25?s123 were the most distant ones. According to the ISSR result, the genetic similarity index changed between 0.21–095; 25?s203 with 25?s112 genotypes were the closest, while 25?s08 and 01KaD2 were the most distant ones. CONCLUSION: The RAPD and ISSR markers were found to be promising for assessing genetic diversity in mulberry genotypes. Copyright © 2011 Society of Chemical Industry     

Comparison of melt extrusion and thermokinetic mixing methods in poly(ethylene terephthalate)/montmorillonite nanocomposites

The scope of this study consists in studying the effects of processing type on thermal stability of poly(ethylene terephthalate) (PET) and its nanocomposites prepared with organically modified clays. To achieve this goal, an intercalating agent was synthesized and montmorillonite type of clay modified with this intercalating agent was mixed with the PET by using melt extrusion and high‐shear thermokinetic mixing method. According to the results, manganese in the raw clay—though chemically bound—was found to be responsible for the decreased intrinsic viscosity (IV) values, i.e. decreased molecular weight in PET/organoclay nanocomposites. Besides, it was revealed that working on the thermokinetic mixer provided substantial contributions such as shorter processing times in comparison to the melt extrusion method, elimination of drying step before melt processing, which has been accepted as an inevitable process for PET so far, less thermal degradation because of short processing times, and more homogeneous and better dispersion of the clay particles in PET matrix phase. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers     

Performance analysis of dual-hop fixed-gain AF relaying systems with OSTBC over Nakagami-m fading channels

In this paper, we present outage probability and symbol error rate (SER) performance analyses of a dual-hop transmission using fixed-gain amplify-and-forward relaying in flat Nakagami-m fading channels. The system under consideration is equipped with multiple antennas at source and destination adopting orthogonal space-time block coding to provide transmit diversity and maximum ratio combining to provide receive diversity, respectively. For integer and half-integer m values, closed forms of exact outage probability and moment generating function (MGF) expressions are derived through cumulative distribution function (CDF) of the overall system signal-to-noise ratio. Closed-form exact SER expressions based on the overall CDF are obtained for binary phase shift keying, binary frequency shift keying and M-ary pulse amplitude modulation. Exact SER expressions based on the MGF method are also obtained for binary differential phase shift keying, M-ary phase shift keying and M-ary quadrature amplitude modulation. Moreover, the asymptotic diversity order analysis is performed through derivations of asymptotic outage probability and SER. Theoretical analyses are validated by Monte Carlo simulations showing perfect match between each other.