Evaluation the Impact of Annealing on Phase Evolution,Microstructure, and Magnetic Properties of Nanocrystalline Ball-Milled LiSm Ferrite

The impact of milling and subsequent annealing on the phase evolution, microstructure and magnetic properties of Li_0.5Sm _x Fe_2.5?x O₄ (x = 0, 0.05, 0.1, 0.2) ferrite prepared by mechanical alloying was investigated. X-ray diffraction (XRD), scanning electron microscope, Fourier transform infrared spectroscopy, laser particle size analysis, and vibrating sample magnetometry were employed to characterize the prepared LiSm compound. The structure was evaluated by XRD, confirmed the formation of its single-phase spinel structure. The magnetic properties of the milled nanostructured powder were extensively affected by the annealing temperature. The substitution of samarium significantly influences the magnetic characteristics, proved by magnetization measurements at room temperature.     

Modeling of conjugated heat transfer in a thick walled enclosure filled with nanofluid

The objective of this paper is to investigate the conjugated heat transfer in a thick walled cavity filled with copper-water nanofluid. The analysis uses a two-dimensional rectangular enclosure under conjugated convective-conductive heat transfer conditions and considers a range of Rayleigh numbers. The enclosure was subjected to a constant and uniform heat flux at the left thick wall generating a natural convection flow. The thicknesses of the other boundaries are assumed to be zero. The right wall is kept at a low constant temperature while the horizontal walls are assumed to be adiabatic. A moveable divider is located at the bottom wall of the cavity. The governing equations are derived based on the conceptual model in the Cartesian coordinate system. The study has been carried out for the Rayleigh number in the range of 10⁵ ≤ Ra ≤ 10⁸, and for the solid volume fraction at 0 ≤ ? ≤ 0.05. Results are presented in the form of streamlines, isotherms, average Nusselt number and input heat absorption by the nanofluid. The effects of solid volume fraction of nanofluids, the location of the divider and also the value of the ambient convective heat transfer coefficient on the hydrodynamic and thermal characteristics of flow have been analyzed. An increase in the average Nusselt number was found with the solid concentration for the whole range of Rayleigh number. In addition, results show that the position of the divider and the ambient convective heat transfer coefficient have a considerable effect on the heat transfer enhancement.     

Application of Deep Hole Drilling to the Measurement and Analysis of Residual Stresses in Steel Shrink‐Fitted Assemblies

Abstract: Residual stress measurement of shrink‐fitted assemblies was achieved through finite element simulations and experiments using the deep hole drilling technique. Shrink‐fitted assemblies using stainless steel and cast iron were manufactured and residual stresses measured using a combination of deep hole and centre hole drilling. The results from the finite element simulations demonstrated that modifications to the deep hole drilling method were required to account for plastic relaxation during the measurement process. This was verified through the experimental measurements. The results from both the stainless steel and cast iron assemblies provided a clear demonstration that the final residual stress state was a consequence of the machining and assembly of the components.     

Effects of UVB on the synthesis of complement proteins by keratinocytes

Conditioned taste aversion is a common classic conditioning procedure used to identify noxious stimuli. When a rat is given a taste solution, the conditioned stimulus (CS), followed by an unpleasant experience, the unconditioned stimulus (US), the rat will avoid consumption of the CS in future presentations. These experiments use the taste aversion procedure to examine the effect of exposure to a high magnetic field. A solution consisting of 3.0 g glucose and 1.25 g saccharin per 1 L of solution (G+S) was used as the CS and a 9.4-T magnet served as the US. In Experiment 1, all rats received a 10 min presentation of the G+S solution followed by either a 30 min exposure to the magnetic field (Magnet, n = 8), a 30-min exposure in a container with similar conditions but lacking the magnetic field (Sham, n = 8), or no exposure (Control, n = 8). The Magnet Group showed a taste aversion on the first day of preference testing (p < 0.05). Experiment 2 employed the same US-CS protocol for 3 consecutive days of conditioning. The Magnet Group demonstrated a taste aversion for the postexposure Days 1-8 (p < 0.01). There was no difference between the Sham and Control Groups in either experiment. The results of this study clearly demonstrate that the rats associated the G+S solution with the experience of being exposed to the high magnetic field and avoided the solution in subsequent presentations.     

Post-mortem stimulation of carcasses: effects on biochemistry, biophysics, microbiology, and quality of meat

The influence of post-mortem electrical stimulation of carcasses on the physicochemical, ultrastructural, microbiological, and quality characteristics of meat have been described at length. The latest views, based on the physiological, biochemical, and mechanical models that have been extended to explain the development of tension (contraction) in muscle are presented. The mechanisms by which electrical stimulation causes improvement in certain quality characteristics of meat are considered with some new thoughts. The significance of the mode of electrical flow through the carcass and how the various electrical parameters (electrode-carcass contact, type of current, voltage, pulse characteristics) affect the rate of glycolysis have been explained. The commercial implications of electrical stimulation in the meat industry are highlighted giving special emphasis to hot-boning, energy conservation, and operator safety.     

The mechanism for the promotion of tenderness in meat during the post‐mortem process: A review

The post‐mortem changes in the chemical composition and structure of striated muscle have been reviewed on the basis of various concepts that emerged from the studies of different investigators to explain the course of tenderization of meat during aging. These concepts include the changes in the sarcoplasmic proteins, myofibrillar proteins (such as complete dissociation of actomyosin, partial dissociation of actomyosin, cleavage of disulfide linkages, depolymerization of F‐actin filaments, cleavage of myosin filaments, disorganization of Z‐bands and the troponin‐tropomyosin complex), sarcolemma, connective tissue elements (collagen fibrils, ground substance), and the protein‐ion relationship of the muscle cells (more strictly, syncy‐tia). The experimental evidence for and against each of the views is discussed critically in the light of certain fundamentals of biophysical chemistry and biochemistry. Finally, an alternative hypothesis has been presented based on the differential effect of the post‐mortem formation of lactic acid (H⁺ ion concentration) on the intra‐ and extracellular components of muscle and the possible role of lysosomal cathepsins. Consequently, a series of biophysical, biochemical, and ultrastructural changes seem to account for the mechanism by which meat becomes tender during the aging process.     

Influence of the Ethylene Glycol, Water Treatment and Microwave Irradiation on the Characteristics and Performance of VPO Catalysts for n-Butane Oxidation to Maleic Anhydride

In this paper, the preparation of vanadium phosphate catalysts was shown to be improved by (1) using V₂O₅ and ethylene glycol as starting and reducing agent material, respectively for VOPO₄ · 2H₂O, (2) subsequent water treatment and (3) microwave irradiation. In particular, the preparation route, based on the reduction of VOPO₄ · 2H₂O with various alcohols, is described in detail and contrasted with other three established methods performed by using ethylene glycol and isobutyl alcohol as reductant and solvent for V₂O₅ or distilled water as a solvent material. The preparation of catalyst precursor is carried out by two different methods, namely conventional heating and microwave irradiation. With this new technique, catalysts derived from the reduction of VOPO₄ · 2H₂O by ethylene glycol exhibit substantially higher surface area (typically >40 m² g^?1) and activity. In fact, the surface area of the catalyst is significantly enhanced when the precursor is refluxed by distilled water and dried by microwave heating. The characterization of catalysts was carried out using X-ray diffraction (XRD), Brunauer–Emmer–Teller (BET) surface area measurement, temperature programmed reduction (H₂-TPR), temperature-programmed reaction (TPRn) and scanning electron microscopy (SEM). This study shows that employing ethylene glycol as reducing agent, followed by adding the water treatment step to catalyst synthesis procedure, and using microwave irradiation would give rise to enhanced surface area, activity and selectivity of the catalyst. Moreover, it introduces a more energy efficient procedure for preparation of vanadium phosphate catalyst used in selective oxidation of n-butane process.     

Isogeometric analysis of coupled thermo-elastodynamic problems under cyclic thermal shock

The isogeometric analysis (IGA) method was extended for the solution of the coupled thermo-elastodynamic equations. The dimensionless formulation was accepted in discretization of the uncoupled and coupled thermoelasticity equations and the Generalized Newmark method was used in the time integration procedure. First, the performance of the proposed method was verified against a two-dimensional benchmark example subjected to constant thermal shock with available exact analytical solutions. Then a two-dimensional half-space benchmark example under thermal shock was solved. Finally, cyclic thermal shock (CTS) loading was applied on the half-space problem. The results dedicated that IGA can be used as a suitable approach in the analysis of the general thermomechanical problems.     

On the practicability of a new bio sorbent: Lasani sawdust and coconut coir for cleanup of oil spilled on water

In this article, two bio-sorbents have been selected: lasani sawdust (LS) (a new bio-based material) and coconut coir (CC) for the removal of used motor oil from the aqueous phase. The physical nature of the materials was characterized using Fourier Transform Infrared Spectroscopy and Constitutional Analysis of lignin and cellulose. The adsorption process was evaluated using various kinetic and adsorption models. The evaluated sorption capacities for coconut coir and lasani sawdust were 12.82?g g^?1 and 0.36?g g^?1, respectively. Maximum sorption of oil from the aqueous solution conveniently took place in 20?minutes. To ascribe statistically which model describes the adsorption phenomenon best, Root Mean Square Error (RMSE) and Average Relative Error (ARE) were used. The kinetics of the adsorption was best described by Pseudo-second order. Similarly, Langmuir isotherm model had the least value for the two error functions and a higher q_max value for coir than for lasani. It was concluded that the increased absorptive ability of coir over lasani was due to the difference in the composition of lignin and cellulose of the two materials.