Optimization of Ultrasound-Assisted Alkali Neutralization in the Refining of Safflower Oil to Minimize the Loss of Bioactive Compounds

In this study, ultrasound-assisted (UA) neutralization parameters are optimized using the response surface methodology to develop a novel alkali neutralization method based on the minimal refining concept. Sodium hydroxide (NaOH), magnesium oxide (MgO), and calcium hydroxide (Ca(OH)₂) are used in both the traditional (TR) and UA neutralizations. Optimum probe depth, duration, and intensity levels are calculated as 3.7 cm, 25 s, and 54.3%, respectively, for UA neutralization with NaOH, which is more successful at free fatty acid (FFA) reduction and total phenolic content (TPC) retention than MgO and Ca(OH)₂. Validation results of optimum conditions show that lowest average FFA content (0.29%) and highest average TPC (211.2 mg kg⁻¹) are determined for the UA-neutralized safflower oil samples. The comparison of all the neutralization experiments reveal that the UA neutralization under optimum conditions using NaOH reduced 82.8% of the FFA content, whereas the TR alkali neutralization reduced the FFA content at a maximum of only 47.8%. Practical Applications: From the results, it can be inferred that the UA neutralization exhibits good performance in FFA content reduction and bioactive compound retention while offering a good solution within the concept of minimal refining.     

WAVE PATTERN PRODUCED BY A HEAT SOURCE MOVING WITH CONSTANT VELOCITY ON THE TOP OF AN INFINITE PLATE

Within the framework of linear, isotropic elasticity theory the wave pattern produced by a heat source moving with constant velocity on the top of an infinite plate is computed. Both the transient effects associated with the initial conditions and the damping of the waves are neglected. If the travel speed of the heat source is smaller than the velocity of the surface waves, dispersive flexural waves will be excited. The frequency of these waves is proportional to the square of the wave number if the wavelength is much larger than the thickness of the sheet. In this limiting case it is found that the crest of the waves makes an angle of 90 degrees with the travel direction, and this result is independent of the travel speed as long as the parabolic approximation remains valid for the dispersion relation of flexural waves.     

Superparamagnetic iron oxide nanoparticles: effect of iron oleate precursors obtained with a simple way

The objective of the study was to investigate the effect of different amounts of iron oleate precursor with different oleic acid amounts on the properties of the synthesised nanoparticles by thermal decomposition. The iron oleate precursors which formed from oleic acids in the order of 0.5, 1.0, 1.5 and 2.0 g, and 0.1 g iron powder was prepared under 200 °C seperately, using a facile solvothermal method under study. Thermal analysis of iron oleat precursors by a thermogravimetric analysis (TGA) revealed that the different amount of oleic acid was seen to have an impact on the thermal properties of iron oleat complexes. During the synthesis of nanoparticles, iron oleate complex in 1-hexadecane kept refluxing for 3 h under air atmosphere resulting in the formation of nanoparticles. The fourier transform infrared spectra measurements and the TGA analysis disclosed that nanoparticles were coated with oleic acid. To the X-ray diffraction patterns, all samples are iron oxide nanocrystals and their crystal sizes increased from 6.4 to 9.8 nm with decreasing oleic acid. Also, the sizes of nanoparticles were found to be in same range as confirmed with the surface observation by a transmission electron microscope. The magnetic properties obtained from a vibrating sample magnetometer revealed that all nanoparticles are superparamagnetic at room temperature. Also, their saturation magnetizations were up to 33.2 emu/g. It is seen that the nanoparticles are superparamagnetic with the desired structural and corresponding magnetic properties and therefore, they could be thought to be convenient for biomedical applications as the particles can be transferred to aqueous phase.     

Performance of an HT‐PEMFC having a catalyst with graphene and multiwalled carbon nanotube support

In this study, the effect of multiwalled carbon nanotube and graphene nanoplatelet‐based catalyst supports on the performance of reformate gas‐fed polybenzimidazole (PBI)‐based high‐temperature proton exchange membrane fuel cell (HT‐PEMFC) was investigated. In addition, the effect of several microwave conditions on the performance of the Pt‐Ru/multiwalled carbon nanotube (MWCNT)–graphene nanoplatelet (GNP) catalyst was assessed. Through X‐ray diffraction, thermal gravimetric analysis, transmission electron microscopy, scanning electron microscopy, and energy dispersive spectroscopy, the catalysts' chemical structure and morphology were characterized. Cyclic voltammetry analysis was used for the electrochemical characterization of catalysts through an electrochemical cell with three electrodes connected to a potentiostat. The results showed that the best performing catalyst is the catalyst produced using 800‐W power for 40 seconds. The electrochemically active surface area values of this catalyst ranged from 54 to 45 m²/g. Single‐cell performance tests of the HT‐PEMFC were then carried out. In these tests, reformate gas mixture, consisting of H₂, CO₂, and CO, was fed to the anode side at 160°C without humidification. These tests for the best performing catalyst yielded peak power density of 0.280 W/cm² and current density (at 0.6 V) of 0.180 A/cm² in the H₂/air environment and peak power density of 0.266 W/cm² and current density (at 0.6 V) of 0.171 A/cm² in the reformate gas/air environment. As a result of the experiments, it was found that Pt‐Ru/MWCNT‐GNP hybrid material is a suitable catalyst for HT‐PEMFC.     

DressBoard: An Embedded Virtual Try-On System for Ties and Bowties

In real life, trying a dress is generally physically exhausting and time consuming. In this study, a novel embedded virtual try-on system for ties and bowties is proposed, which will save time and enhance the shopping experience. The presented system is based on human computer interaction with embedded design, where the goal is to simulate tie/bowtie trial on a person in the camera view. Users can choose a tie/bowtie model available in the database via a touch screen. The system will then fit the selected model rapidly and accurately, and display the fitting result. Performance of the proposed system is experimentally evaluated on images acquired in a real-life scenario. The results showed that both fitting accuracy and process time vary almost-linearly with image resolution, where real-time and accurate (average error varies in the 0.5–5.0 cm range by resolution) performance can be achieved. In addition, the proposed system can handle fitting in videos, where experimental evaluations revealed real-time, accurate, and robust (to illumination change and image variations) performance even in the absence of collared garment.     

Bubbly cavitating flow generation and investigation of its erosional nature for biomedical applications

This paper presents a study that investigates the destructive energy output resulting from hydrodynamic bubbly cavitation in microchannels and its potential use in biomedical applications. The research performed in this study includes results from bubbly cavitation experiments and findings showing the destructive effects of bubbly cavitating flow on selected solid specimens and live cells. The bubbles generated by hydrodynamic cavitation are highly destructive at the surfaces of the target medium on which they are carefully focused. The resulting destructive energy output could be effectively used for biomedical treatments, such as destroying kidney stones (renal calculi) or killing cancer cells. Motivated by this potential, the cavitation damage to cancerous cells and material removal from chalk pieces (which possess similar material properties as some kidney stones) was investigated. Our results showed that cavitation could induce damage both on chalk pieces and leukemia/lymphoma cells. We discovered that hydrodynamic cavitation exposure had early and delayed effects on cancer cell survival. Hence, the potential of hydrodynamic bubbly cavitation generated at the microscale for biomedical treatments was revealed using the microchannel configuration as a microorifice (with an inner diameter of 147 μm and a length of 1.52 cm), which acts as the source of bubbly cavitating flows.     

An Adhesion-Dominated Rolling Friction Regime Unique to Micro-scale Ball Bearings

We demonstrate that micro-scale rolling bearings exhibit friction and wear properties markedly different from their macro-scale counterparts. A microfabricated testing platform uses variable rolling element diameters or vapor-phase lubricated interfaces to independently test friction force with varying contact area and surface energy. A linear, consistent, relationship between friction force and contact area is observed among different rolling element diameters. When surface free energy is altered through the introduction of vapor-phase lubrication, an 83 % decrease in friction is observed. When coupled with observed ball material adhered to the raceway, there is strong evidence for adhesion-dominated rolling friction regime at the micro-scale.     

Effects of particle size and electrical resistivity of filler on mechanical,electrical, and thermal properties of linear low density polyethylene–zinc oxide composites

The effects of particle size and electrical resistivity of zinc oxide (ZnO) on mechanical properties, electrical and thermal conductivities of composites made with linear low density polyethylene (LLDPE) were investigated. Micron sized (mZnO), submicron sized (sZnO), and nano sized (nZnO) powders having resistivities of 1.5 × 10⁶, 1.5 × 10⁹, and 1.7 × 10⁸ were used to prepare composites with 5–20 vol % filler. The tensile strength was lowered and the modulus of elasticity of the composites was increased with ZnO addition. Rather than the particle size of the ZnO, its initial resistivity and aspect ratio affected the resistivity of composites. The resistivity of the LLDPE was lowered from 2.3 × 10¹⁶ Ω cm down to 1.4 × 10¹⁰ Ω cm with mZnO addition. Thermal conductivity of the composites was increased with ZnO addition 2.5–3 times of the polymer matrix. The composites can be used for electrostatically dissipating and heat sink applications due to their decreased electrical resistivity and increased thermal conductivity. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2734–2743, 2013     

The Triple Helix as a model to analyze Israeli Magnet Program and lessons for late-developing countries like Turkey

Although the systemic changes towards innovation networking between university-industry and governmental actors have recently found a place on the international policy and literature agenda, networking between the organizations and people - for the national survival, production and growth - has been deeply rooted in the Israeli system even before the establishment of the Israeli State in 1948. Internal and international constraints fostered the formation of personal links, as did institutional settings that promoted networking. This paper reviews the interaction of societal, organizational and cultural features that render innovation networks in Israel successful. The research focuses on the impacts of the Israeli Magnet Program on the Israeli R&D growth and performance. The implications of innovation networks for a late-developing country like Turkey are reviewed in the contexts of catching-up and cross-regional collaboration between the Israeli and Turkish industries and academies.