Formation and Organization of Amino Terminated Self-assembled Layers on Si(001) Surface

We have investigated the effects of dipping time, solution concentration and solvent type on the formation of self-assembled monolayers with aminosiloxane molecules (i.e., N-(3 trimethoxysilylpropyl)diethylenetriamine (TPDA)) on the Si(001) surface. Studies performed with an ellipsometer showed that monolayers with a thickness of about 1.2 nm were formed when the dipping time is about 2 h, while multilayer were observed for longer time periods. The effect of the TPDA concentration on the thickness of the deposited layer was not very profound, however, the contact angle data exhibit importance of concentration on the surface coverage. The type of the solvent used in the formation of the monolayers was found an important parameter. Monolayers were formed with solvent having larger dielectric constants. Relatively thick multilayer was observed when benzene was used as the solvent, due to its quite low dielectric constant (hydrophobicity).     

Effects of concentration and temperature on the coupled heat and mass transport in liquid mixtures

Using published experimental data on the thermal conductivity, mutual diffusivity, and heats of transport, the degree of coupling between heat and mass flows has been calculated for binary and ternary nonideal liquid mixtures. The binary mixtures consist of two types: the first is six systems of six-to-eight-carbon straight and branched chain alkanes in chloroform and in carbon tetrachloride; and the second is mixtures of carbon tetrachloride with benzene, toluene, 2-propanone, n-hexane, and n-octane. The ternary mixture considered is toluene-chlorobenzene-bromobenzene. The published data are available at 25°C, 30°C and 35°C and ambient pressure. Using the linear nonequilibrium thermodynamics (LNET) and the dissipation-phenomenological equation (DPE) approach, the effects of concentration, temperature, molecular weight, chain-length, solute, solvent, and branching on the degree of coupling are examined. The extent of coupling and the thermal diffusion ratio are expressed in terms of the transport coefficients to obtain a better understanding of the interactions between heat and mass flows in liquid mixtures. It is found that the composition of the heavy component bromobenzene changes the direction and magnitude of the two-flow coupling in the ternary mixture.     

Supplier selection problem in global supply chains by AHP and ANP approaches under fuzzy environment

In this paper, we proposed a model for selecting of the global supplier by analytical hierarchy process (AHP) and analytical network process (ANP) based on linguistic variable weight. The fuzzy AHP and fuzzy ANP methods are suggested to be a good tool for solving our proposed multiple-criteria decision-making problem. Fuzzy AHP-based methodology evaluated different decision criteria such as service quality, cost, risk factors, and supplier’s characteristics involved in the selection of the best supplier in a global supply chain and ANP represented an effective tool for providing a suitable solution for managers. The linguistic levels of comparisons produced by the experts with triangular fuzzy numbers for constructing fuzzy pairwise comparison matrices. The implementation of the system was demonstrated by a problem having four stages of hierarchy which contains four criteria and 28 attributes. In conclusion, the fuzzy AHP and fuzzy ANP results were compared.     

DNA adsorption on poly(N,N‐dimethylacrylamide)‐grafted chitosan hydrogels

In this study, poly(N,N‐dimethylacrylamide) grafted chitosan (PDMAAm‐g‐CT) hydrogels were prepared for deoxyribonucleic acid (DNA) adsorption. Instead of directly grafting the N,N‐dimethylacrylamide (DMAAm) monomer onto the chitosan (CT) chains, poly(N,N‐dimethylacrylamide) with carboxylic acid end group (PDMAAm‐COOH) was firstly synthesized by free‐radical polymerization using mercaptoacetic acid (MAAc) as the chain‐transfer agent and then grafted onto the CT having amino groups. The synthesis of PDMAAm‐COOH and its grafting onto the CT chains were confirmed by attenuated total reflectance Fourier transform infrared (ATR‐FTIR) spectroscopy. From gel permeation chromatography measurements, the number‐average molecular weight (M _n) and polydispersity index of PDMAAm‐COOH were found as 2400 g/mol and 2.3, respectively. The PDMAAm‐g‐CT hydrogels were utilized as the adsorbents in DNA adsorption experiments conducted at +4°C in a trisEDTA solution of pH 7.4. The hydrogels produced with higher PDMAAm‐COOH content exhibited higher DNA adsorption capacity. The DNA adsorption capacity up to 4620 μg DNA/g dry gel could be achieved with the PDMAAm‐g‐CT hydrogels prepared in 80.0 wt % PDMAAm‐COOH feed concentration. This value is approximately seven times higher than that of CT alone. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Petroleum Source Rock Assessments of the Upper Permian Strata in the Central Taurus Region of Turkey

This study presents the hydrocarbon source rock potential and organic maturity of the Upper Permian Tozara Formation in the Gazipa?a-Sugözü area in the central Taurus region. The Tozara Formation deposited oxic to dysoxic shelf conditions consists of algal limestone and organic matter-rich shales. In order to assess the hydrocarbon source rock potential of the Upper Permian lithologies, two different stratigraphic sections described and sampled for organic geochemical analyses and determination of mineralogical composition.     

LOWER CARBONIFEROUS SHALES IN THE EASTERN TAURIDE BELT,SOUTHERN TURKEY: SOURCE ROCK CHARACTERISTICS

Lower Carboniferous (Tournaisian‐Visean) shales, sandstones and limestones are exposed at the surface in autochthonous units in the Eastern Taurides, southern Turkey. This study investigates the organic geochemical characteristics, thermal maturity and depositional environments of shale samples from two outcrop locations in this area (Belen and Naltas). The total organic carbon (TOC) contents range from 0.11 to 5.61 wt % for the Belen samples and 0.04 to 1.74 wt % for the Naltas samples. T_max values ranging from 432–467 °C indicate that the samples are in the oil generation window T_max and are thermally mature. Rock‐Eval pyrolysis data indicate that the organic matter in the shales is composed mainly of Type II and III kerogen. Solvent extract analyses of the samples show a unimodal n‐alkane distribution with a predominance of low carbon number (C₁₃‐C₂₀) n‐alkanes. Pr/Ph ratios and CPI values range from 1.57–1.66 and 1.08–1.11, respectively Pr/n‐C₁₇ and Ph/n‐C₁₈ ratios also indicate that the shales consist of mixed Type II/III organic matter. Sterane distributions are C₂₇>C₂₉>C₂₈ as determined by the sum of normal and isosteranes, suggesting marine depositional conditions 20S/(20S+20R) and ββ (ββ+αα) C₂₉ sterane ratios range from 0.51–0.54 and 0.53–0.57, respectively. These values are high and 20S/(20S+20R) sterane isomerisation has reached equilibrium values. Tricyclic terpanes are abundant on m/z 191 mass chromatograms and C₂₃ tricyclic terpanes are the dominant peak, which indicates a marine depositional setting. C₂₉ norhopane has a higher concentration than C₃₀ hopane, and C₃₀ diahopane and C₂₉Ts are present in all the samples. Ts and Tm were recorded in similar abundances. Moretane/hopane ratios are very low. 22S homohopanes are dominant over 22R homohopanes, and the C₃₂ 22S/(22R + 22S) C₃₂ homohopane ratios are between 0.58 and 0.59, indicating that homohopane isomerisation has reached equilibrium. C₃₁ homohopanes are dominant and the abundance of homohopanes decreases towards higher numbers. Although regional variations in the level of thermal maturity of Upper Palaeozoic sediments throughout the Taurus Belt region largely depend on burial depth, organic geochemical data indicate that the Lower Carboniferous shales in the eastern Taurus region (Naltas and Belen locations) have potential to generate hydrocarbons. These shales are thermally mature and have entered the oil generation window.     

Design and analysis of minkowski reflectarray antenna using 3‐D CST microwave studio‐based neural network model with particle swarm optimization

This article presents a systematic analysis and design of the X‐band Minkowski reflectarray antenna (RA) by using the 3‐D Computer Simulation Technology Microwave Studio (CST MWS)‐based multilayer perceptron neural network (MLP NN) model of a unit element. This MLP NN model is utilized efficiently as a fast and accurate model within a particle swarm optimization procedure to determine the calibration phasing characteristic belonging to the resultant optimum patch geometry and substrate. In design stage, the MLP NN analysis model is reversed to determine the variable‐size of each reflectarray element to meet the necessary phase delay with the adaptive iterative step. In the final stage, the optimum Minkowski RA consisting of the variable‐size Minkowski patches interspaced by 0.5 wavelength at the frequency of 11 GHz on the Taconic RF‐35 with ε_r = 3.54, tan δ = 0.0018 and the optimum thickness (h_opt) are analyzed using the 3D CST MWS and compared with the counterpart square and parabolic reflectors. Compared with the counterpart RA with square element and the parabolic reflector, this optimized Minkowski RA is resulted to be capable of providing higher realized gain and lower sidelobe level (SLL). Furthermore, the effect of feed movement along the focal length on the gain‐bandwidth and radiation pattern is also worked out and demonstrated. It is concluded that this method can also be applied as a robust method for the design and analysis of a RA built by arbitrarily shaped patches. © 2013 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2013.     

Pressure Sensitive Adhesion of an Elastomeric Protein Complex Extracted From Squid Ring Teeth

The pressure sensitive adhesion characteristic of a protein complex extracted from squid ring teeth (SRT), which exhibits an unusual and reversible transition from a solid to a melt, is studied. The native SRT is an elastomeric protein complex that has standard amino acids, and it does not function as adhesives in nature. The SRT can be thermally shaped into any 3D geometry (e.g., thin films, ribbons, colloids), and it has a glass transition temperature of 32 °C in water. Underwater adhesion strength of the protein film is approximately 1.5–2.5 MPa. The thermoplastic protein film could potentially be used in an array of fields, including dental resins, bandages for wound healing, and surgical sutures in the body.     

Materials Fabrication from Native and Recombinant Thermoplastic Squid Proteins

Natural elastomers made from protein extracts have received significant interest as eco‐friendly functional materials due to their unique mechanical and optical properties emanating from secondary structures. The next generation sequencing approach is used to identify protein sequences in a squid ring teeth complex extracted from Loligo vulgaris and the use of recombinant expression is demonstrated in the fabrication of a new generation of thermoplastic materials. Native and recombinant thermoplastic squid proteins exhibit reversible solid to melt phase transition, enabling them to be thermally shaped into 3D geometries such as fibers, colloids, and thin films. Direct extraction or recombinant expression of protein based thermoplastics opens up new avenues for materials fabrication and synthesis, which will eventually be competitive with the high‐end synthetic oil based plastics.     

Effects of process stages on Turkish delight/lokum microbiological quality

The sources of microbiological contamination at the lokum production lines of two local confectionaries were determined. Surface samples from the production lines were evaluated by standard and ATP bioluminescence methods. Microbial loads of raw materials were also determined. The trays and cutting knives were found to be the primary contamination sources, and personnel hands were found to be the secondary contamination sources, while all of them were found to be the secondary sources when the standard swab method was applied. Raw materials were not sources of contamination, because of their microbiological loads and the following high‐temperature cooking stages. The microbial loads of lokum also were not high, due to product contents and the processes applied to lokum. There is a need for further studies related to the effects of process steps on the physical and the chemical quality of lokum. Training for workers in food safety at the confectionaries is also needed.