Effects of variable electric conductivity and non-uniform heat source (or sink)on convective micropolar fluid flow along an inclined flat plate with surfaceheat flux

Numerical simulations have been carried out to investigate the effects of the fluid electric conductivity and non-uniform heat source (or sink) on two-dimensional steady hydromagnetic convective flow of a micropolar fluid (in comparison with the Newtonian fluid) flowing along an inclined flat plate with a uniform surface heat flux. The local similarity solutions are presented for the non-dimensional velocity distribution, microrotation, and temperature profiles in the boundary layer. The significance of the physical parameters on the flow field is discussed in detail. The results show that the values of the skin-friction coefficient and the Nusselt number are higher for the case of constant fluid electric conductivity compared with those for the variable fluid electric conductivity. The effect of temperature dependent heat generation is much stronger than the effect of surface dependent heat generation. The results also show that effects of the fluid electric conductivity and non-uniform heat generation in a micropolar fluid are less pronounced than that in a Newtonian fluid.     

Feasibility of Thermoplastic Composite Jackets for Bridge Impact Protection

The research focused on the effects of low velocity impact loading on high-strength concrete confined by a prefabricated polypropylene jacket and comparing the results with similar specimens confined by carbon fiber-reinforced polymer (CFRP) composites. In order to accomplish this, both static and dynamic load tests were performed. Concrete cylinders were used for static loading. Twelve concrete cylinders were prepared for static load testing: three were plain concrete and used as control specimens, three were wrapped with one layer of unidirectional CFRP composites, and six were confined by the polypropylene jacket. The thickness of the polypropylene wrap was machined to different thicknesses; three 3?mm and three 6?mm. The cylinders were standard (D×H) 152?mm×305?mm. Cylinders were loaded to failure in uniaxial compression using a Tinius-Olsen Universal Testing Machine. Impact testing was performed using four (D×H) 152?mm×914?mm columns. The columns consisted of one control sample; one CFRP composites wrapped, and two (one of each thickness) wrapped with polypropylene. Impact testing was conducted using an Instron drop-tower testing machine.     

A single-step procedure for estimating seismically-induced displacements in earth structures

Estimation of the permanent deformations of embankment dams is, in practice, based upon the simplifying assumption that dynamic-acceleration response and wedge sliding are two separate processes (decoupled ‘elastic’ and ‘rigid-slip’ features of the dynamic response). An alternative hypothesis is proposed in this paper, namely that these two processes occur simultaneously. To this end, the dam is assumed to contain an a priori assigned, potentially-sliding interface, and the dynamic response is computed in a single step. As a validation of the new single-step procedure, a numerical analysis is carried out and shown to successfully explain the asymmetric response of La Villita Dam recorded during the Mexico earthquake of 15 September, 1985. All analyses are performed with ADINA using special interface elements to model the slip and Newmark's time-integration algorithm for a direct step-by-step solution.     

Electrochemically assisted metal uptake by cation exchange based chemically modified electrodes

Carbon paste electrodes containing powdered cation exchange resin (Amberlite IR120) have been fabricated and applied to the uptake of copper ion in aqueous solution. The copper uptake reaction was carried out at open circuit and at different cathodic potentials. Linear potential sweep voltammetry was used to quantify the accumulated ions. With the application of an optimum cathodic potential, the amount of copper absorbed increased four to nine-fold in comparison with similar uptake at open circuit conditions. The effect of different resin size employed in the chemically modified electrodes, on the sensitivity of the electrode response was also studied as a function of peak current.     

A computer program for nonlinear analysis of pressure vessels

This paper describes the nonlinear analysis of pressure vessels necessary for taking into account the large deformations that take place at the junctions of shells of different geometries. Specifically, a computer program has been developed, based on both the linear and nonlinear theories of shells, which obtains numerical solutions for the most commonly used types of pressure vessels, namely those with spherical, ellipsoidal or conical heads and also flat-end pressure vessels. A multisegment integration technique has been used to obtain the solutions of the governing equations. The computed solutions are found to be highly accurate when compared with the known results of simple shells, as no nonlinear analysis is reported in the literature on the shell junctions in pressure vessels.     

Near‐infrared reflectance spectroscopy for determining end‐point temperature of heated fish and shellfish meats

Attempts have been made to assess the end‐point temperature (EPT) of heated fish and shellfish meats by near‐infrared (NIR) reflectance spectroscopy. Since the presence of water affects NIR spectra, the influence of the water content of samples on the performance of NIR spectroscopy for determining EPT was also evaluated. Blue marlin (Makaira mazara), skipjack (Katsuwonus pelamis), red sea bream (Pagrus major), kuruma prawn (Penaeus japonicus) and scallop (Patinopecten yessoensis) meats were heat‐treated at different temperatures (5 °C intervals between 60 and 100 °C). NIR spectra were measured at 2 nm intervals between 1100 and 2500 nm. A stepwise multiple linear regression method was used to develop a calibration curve. Changes in NIR reflectance spectra upon heat treatment were related to the heating temperature. Moreover, the interference from the variation in water content on the prediction of EPT was eliminated by selecting appropriate wavelengths. Plotting of NIR‐predicted temperatures determined from d² log(1/R) at four specific wavelengths against the actual EPT revealed a promising linear relationship with correlation coefficients between 0.94 and 0.98. In the temperature range 60–100 °C, NIR reflectance spectroscopy was able to detect EPT of heated fish and shellfish meats with a prediction error of 1.9–3.1%. © 2002 Society of Chemical Industry     

Phytosterols and their extraction from various plant matrices using supercritical carbon dioxide: a review

Phytosterols provide important health benefits: in particular, the lowering of cholesterol. From environmental and commercial points of view, the most appropriate technique has been searched for extracting phytosterols from plant matrices. As a green technology, supercritical fluid extraction (SFE) using carbon dioxide (CO₂) is widely used to extract bioactive compounds from different plant matrices. Several studies have been performed to extract phytosterols using supercritical CO₂ (SC‐CO₂) and this technology has clearly offered potential advantages over conventional extraction methods. However, the efficiency of SFE technology fully relies on the processing parameters, chemistry of interest compounds, nature of the plant matrices and expertise of handling. This review covers SFE technology with particular reference to phytosterol extraction using SC‐CO₂. Moreover, the chemistry of phytosterols, properties of supercritical fluids (SFs) and the applied experimental designs have been discussed for better understanding of phytosterol solubility in SC‐CO₂. © 2014 Society of Chemical Industry     

Species Authentication Methods in Foods and Feeds: the Present,Past, and Future of Halal Forensics

We extensively reviewed the existing as well as the potentials of the molecular biology and nanotechnology methods for the identification of animal-derived materials in foods and feeds. The verification of animal-derived materials in foods and feeds is mandatory by several religious as well as regional and state laws. It is also essential to limit the transmission of food-borne pathogens and allergens. Verification of declared components further helps prevent unfair trades and protect consumers' trusts, religious faiths, and hard-earned fortunes. In this review, special emphasis is given to the molecular markers and their tracing tools in biology and nanotechnology. Among the four types of biomolecules, known as proteins, lipids, carbohydrates, and nucleic acids, DNA has been reported as the most appropriate biomarker to identify the source of animal-derived materials. While PCR has got enormous attention as the most effective molecular identification tool, PCR-based methods are not suitable for the unambiguous identification of very short DNA targets (15–30 bp) which can survive even in the harsh conditions of food and feed processing. Nanotechnology-based approaches using nanogap electrodes, quantum dots (QDs), and SERS-active nanoparticle shells are highly sensitive and can detect very short oligo targets almost at single-molecule sensitivity. However, nanogap fabrication has remained a challenging task and also involves complicated surface modification and immobilization chemistries. QD and SERS-based techniques also demand surface modifications and immobilization chemistries. On the other hand, gold nanoparticle (GNP)-based hybridization detection is label-free, sensitive, and does not involve any modification chemistry and expensive instrumentations. GNP-based biosensors offer a low-cost platform to detect and quantify short-length DNA markers in mixed biological and processed commercial foods.     

Influence of variable viscosity and thermal conductivity,hydrodynamic, and thermal slips on magnetohydrodynamic micropolar flow: A numerical study

Thermophysical and wall‐slip effects arise in many areas of nuclear technology. Motivated by such applications, in this article, the collective influence of variable‐viscosity, thermal conductivity, velocity and thermal slip effects on a steady two‐dimensional magnetohydrodynamic micropolar fluid over a stretching sheet is analyzed numerically. The governing nonlinear partial differential equations have been converted into a system of nonlinear ordinary differential equations using suitable coordinate transformations. The numerical solutions of the problem are expressed in the form of nondimensional velocity and temperature profiles and discussed from their graphical representations. The Nachtsheim‐Swigert shooting iteration technique together with the sixth‐order Runge‐Kutta integration scheme has been applied for the numerical solution. A comparison with the existing results has been done, and an excellent agreement is found. Further validation with the Adomian decomposition method is included for the general model. Interesting features in the heat and momentum characteristics are explored. It is found that a greater thermal slip and thermal conductivity elevate thermal boundary layer thickness. Increasing Prandtl number enhances the Nusselt number at the wall but reduces wall couple stress (microrotation gradient). Temperatures are enhanced with both the magnetic field and viscosity parameter. Increasing momentum (hydrodynamic) slip is found to accelerate the flow and elevate temperatures.