HALL EFFECTS ON UNSTEADY FLOW DUE TO NON-COAXIALLY ROTATING DISK AND A FLUID AT INFINITY

An investigation is made on the unsteady magnetohydrodynamic (MHD) flow caused by the non-coaxial rotation of a disk and a fluid at infinity being permeated by a transverse magnetic field. The disk is porous and nonconducting and executes oscillations in its own plane. The Laplace transform method is used to obtain the exact solution of the velocity field. The structure of the steady and unsteady flow fields is investigated. It is shown that the ultimate steady-state blowing solution is established in the presence of Hall current also for resonant frequency, which was not possible in the hydrodynamic case. The combined effects of Hall current, rotation, and suction or blowing are examined. The physical significance of mathematical results is given with various limiting cases.     

Oxidative stability enhancement of broiler bird meats with α-lipoic acid and α-tocopherol acetate supplemented feed

Depression of meat quality is known to be caused by lipid peroxidation occurring in meat. Supplementation of antioxidants in feed decreases lipid peroxidation and improves the oxidative stability of meat after slaughtering. The present study demonstrated that meat obtained from broiler birds fed feed supplemented with α-tocopherol acetate (200 mg/kg feed) along with α-lipoic acid (25, 75, or 150 mg/kg feed) exhibited increased oxidative stability and reduced fat content. The total phenolic content and α-lipoic acid content increased in the meat as the concentration of α-lipoic acid supplementation increased. The protein content in the meat was not changed by the supplementation of α-lipoic acid and α-tocopherol acetate. The results of DPPH and TBA assays demonstrated that feed supplemented with α-lipoic acid and α-tocopherol acetate also enhanced the antioxidant activity of broiler meat. On the other hand, the meat from broiler birds fed feed supplemented with oxidised oil (4% in feed) reduced its oxidative stability.     

Wastewater treatment by adsorption with electrochemical regeneration using graphite-based adsorbents

An innovative technology for wastewater treatment using adsorption and electrochemical regeneration has been developed at the University of Manchester. The process uses a low capacity graphitic adsorbent material (a graphite intercalation compound, Nyex^TM 1000) which can be regenerated electrochemically. In this study, we investigate the characteristics of a new, partially porous adsorbent material, Nyex^TM 2000 which offers increased surface area in comparison with Nyex^TM 1000. Nyex^TM 2000 was found to have an adsorption capacity of almost three times that of Nyex^TM 1000. The electrical conductivity of a Nyex^TM 2000 was found to be double that of Nyex^TM 1000, enabling improvements in the electrochemical regeneration characteristics. The removal of an anionic azo dye, acid violet 17, from aqueous solution using Nyex^TM 1000 and 2000 was investigated under various operating conditions. The adsorption of acid violet 17 on Nyex^TM 2000 was found to be comparatively fast with 75 % of the equilibrium capacity being achieved within 5 min. The parameters affecting the regeneration efficiency including the charge passed, current density, treatment time, adsorbent bed thickness, and pH were investigated. An electrochemical regeneration efficiency of around 100 % was achieved for a fully loaded Nyex^TM 2000 in a sequential batch electrochemical cell with a regeneration time of 60 min and a charge passed of 100 C g⁻¹ at a current density of 14 mA cm⁻². The charge required for electrochemical regeneration was found to be approximately equal to theoretical charge required for complete oxidation of the adsorbed acid violet 17, making process design relatively simple. Nyex^TM 2000 was found to be an economic adsorbent with relatively small electrical energy consumption required (31 J mg⁻¹ of acid violet 17 treated, compared to 52 J mg⁻¹ of acid violet 17 for Nyex^TM 1000). Multiple adsorption/regeneration cycles presented no loss in adsorptive capacity and material loses over five adsorption/regeneration cycles.     

Effects of supranutritional dietary vitamin E levels on subcellular deposition of α-tocopherol in the muscle and on pork quality

The influence of three levels of vitamin E in the diet of pigs on the subcellular deposition of α-tocopherol in the muscle and on selected quality characteristics of pork meat (oxidative stability of lipids, colour, drip loss, microbial growth) was studied. The content of α-tocopherol in adipose tissue and L. dorsi muscle as well as in mitochondrial and microsomal fractions of the muscle significantly increased (P < 0.05) with increasing levels of dietary vitamin E. The differences in the concentrations of α-tocopherol in the subcellular fractions were evident in the enhanced stability of the membranes when exposed to metmyoglobin/hydrogen peroxide. The beneficial effect of dietary vitamin E on the oxidative stability of pork lipids during the storage of pork chops and ground pork was also demonstrated. Even though lipid oxidation increased in all cases during storage, the pork products from the pigs receiving the highest level of vitamin E (200 IU kg^?1 feed) exhibited the smallest increase in thiobarbituric acid reactive substances. In addition, increased colour stability and decreased drip loss were observed on keeping pork chops, which had been previously frozen for three months, at 4°C under fluoresent light for 10 days. The possible effect of α-tocopherol on membrane fluidity in this context is discussed.     

Optimization in measurement of MVC and active stiffness in wrist using the quick release method

The quick release method was used for measurement of Biomechanical parameters in the wrist joints. Wrist joint was previously studied in many researches for its biomechanical characteristics. However, more automation in measurement process has been discussed. In this research, a new test rig with a specified control unit was fabricated. Measurement of parameters in few seconds after the release was considered in the design of the new test rig. Based on reliability tests performed, the fabricated test rig showed firmly reliable measurements for maximum voluntary contraction, and active stiffness. These were true for both cases of left and right wrists during flexion and extension.     

MRI-compatible intensity-modulated force sensor for cardiac catheterization procedures

This paper presents a novel, magnetic resonance imaging (MRI)-compatible, force sensor suitable for cardiac catheterization procedures. The miniature, fiber-optic sensor is integrated with the tip of a catheter to allow the detection of interaction forces with the cardiac walls. The optical fiber light intensity is modulated when a force acting at the catheter tip deforms an elastic element, which, in turn, varies the distance between a reflector and the optical fiber. The tip sensor has an external diameter of 9 Fr (3?mm) and can be used during cardiac catheterization procedures. The sensor is able to measure forces in the range of 0-0.85?N, with relatively small hysteresis. A nonlinear method for calibration is used and real-time MRI in vivo experiments are carried out, to prove the feasibility of this low-cost sensor, enabling the detection of catheter-tip contact forces under dynamic conditions.     

A carbon gel catalyst layer for the roll-to-roll production of dye solar cells

Carbon gel catalyst layers were used in dye solar cells. These layers were prepared on flexible plastic substrates at low temperatures (130 °C). The carbon gel, demonstrated excellent flexibility which is an important feature for roll-to-roll production and special applications of dye solar cells. The use of these low cost and highly flexible catalyst layers resulted in good photovoltaic performance; only 10% lower than dye solar cells with rigid glass-based counter electrodes prepared with thermal platinization at ∼400 °C temperature.     

Aliphatic polyurethane–montmorillonite nanocomposite coatings: Preparation,characterization, and anticorrosive properties

Polyurethane (PU)–clay nanocomposite coatings were prepared by a sonication method. The stability and morphology of these coatings was characterized by turbidometry, X‐ray diffraction, and transmission electron microscopy. The anticorrosive properties of these coatings were investigated by salt‐spray and electrochemical impedance spectroscopy methods. According to the results, dispersed nanoclay layers in the matrix of the nanocomposite coating compositions led to superior anticorrosive characteristics compared to those of pure PU coatings. The best results were obtained with coatings containing about 5 wt % clay. The resistance of the coating containing 5% clay was about 9.002 GΩ after 225 days of immersion in a 3.5 wt % NaCl solution, whereas it was only 97 kΩ for the pure PU coating. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

The Effect of Nanoparticles on the Mass Transfer in Liquid–Liquid Extraction

This article investigates the effect of nanoparticles on mass transfer in the liquid–liquid extraction for the chemical system of n-butanol–succinic acid–water. For this purpose, nanofluids containing various concentrations of ZnO, carbon nanotubes (CNT), and TiO₂ nanoparticles in water, as base fluid, were prepared. To examine the flow mode effect on mass transfer rate, different fluid modes including dropping and jetting were employed in the process. Results show that mass transfer rate enhancement depends on the kinds and the concentration of nanoparticles and the modes of flow. It was observed that after adding nanoparticles, the mass transfer rate significantly increases up to two-fold for ZnO nanoparticles. Furthermore, the results indicate that under the circumstances in which the mass flow rate is high enough, the effect of nanoparticles on the mass transfer phenomenon is too slight.     

Tunable ferroelectric impedance matching networks and their impact on digital modulation system performance

In this paper the bit error rate performance and error vector magnitude of a tunable impedance matching network is analyzed assuming QPSK, 16-QAM and 64-QAM digital modulation schemes. The characterized tunable impedance matching network is based on barium–strontium–titanate ferroelectric thick-film varactors. Inherent dispersive behavior is subsumed into the forward transmission of the passive device. Due to this nonlinear phase response, in general to maximize the overall system performance, an agile tuning of the varactor values is demonstrated, taking into account the phase and group delay of s₂₁ parameter. Detailed signal simulation results based on measured data of a testbed are presented. The influence of varying matched impedances on the tuning behavior with different modulation bandwidths is discussed at a center frequency of 1.9 GHz.