Formulation of ELF magnetic fields' effects on malondialdehyde level and myeloperoxidase activity in kidney using genetic programming

In vivo exposure effects of electromagnetic fields (EMFs) on various tissues of experiment animals have been investigated. In this sense, modeling and formulation of these biological effects have been of significant importance. In this study extremely low frequency (ELF) EMFs effects on malondialdehyde (MDA) level and myeloperoxidase (MPO) activity in kidney of guinea pigs exposed to 50 Hz magnetic fields of 1 mT, 2 mT and 3 mT have been presented. It has been planned to determine whether genetic programming (GP) is appropriate to analyze and formulate these biological effects. Consequently, it has been observed that GP can be effectively used to model MDA level and MPO activity. The performances of prediction of the proposed GP formulation versus actual experimental values are found to be quite satisfactory in terms of standard deviation and correlation coefficient. It is concluded that the GP application serves to form a database for the researchers in this field, without exposing tissues to EMF and without using too many guinea pigs.     

Jgroup/ARM: a distributed object group platform with autonomous replication management

This paper presents the design and implementation of Jgroup/ARM, a distributed object group platform with autonomous replication management along with a novel measurement‐based assessment technique that is used to validate the fault‐handling capability of Jgroup/ARM. Jgroup extends Java RMI through the group communication paradigm and has been designed specifically for application support in partitionable systems. ARM aims at improving the dependability characteristics of systems through a fault‐treatment mechanism. Hence, ARM focuses on deployment and operational aspects, where the gain in terms of improved dependability is likely to be the greatest. The main objective of ARM is to localize failures and to reconfigure the system according to application‐specific dependability requirements. Combining Jgroup and ARM can significantly reduce the effort necessary for developing, deploying and managing dependable, partition‐aware applications. Jgroup/ARM is evaluated experimentally to validate its fault‐handling capability; the recovery performance of a system deployed in a wide area network is evaluated. In this experiment multiple nearly coincident reachability changes are injected to emulate network partitions separating the service replicas. The results show that Jgroup/ARM is able to recover applications to their initial state in several realistic failure scenarios, including multiple, concurrent network partitionings. Copyright © 2007 John Wiley & Sons, Ltd.     

Preparation and characterization of zeolite beta–polyurethane composite membranes

Incorporation of zeolite into polyurethane (PU) membranes was investigated by using as‐synthesized and calcined zeolite beta particles at two different loading contents (0.1 and 1 wt %). The chemical interaction between the zeolite beta crystals and PU was observed by ATR‐FTIR spectroscopy. The SEM results suggested that the calcined zeolite beta crystals were more homogeneously dispersed in the composite membranes than the as‐synthesized zeolite beta crystals. DMA results demonstrated that all composite membranes had higher storage modulus in the rubbery state and higher stability towards thermal and mechanical degradation with respect to the control groups. Tensile testing results also showed increased tensile strength and elongation at break for all composite membranes. This study suggests that incorporating zeolite beta in its as‐synthesized or calcined forms and at different amounts can be applied as an alternative method for tailoring the mechanical properties of PU membranes without changing its structural characteristics. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

CFD analysis on the influence of helical carving in a vortex flow solar reactor

Solar thermal cracking of natural gas is a promising technology, which has attracted researchers in recent years for its potential to lead to the development of CO₂ free hydrogen production process. However, experimental access to the reaction chamber of solar cracking reactors is a challenge due to the high temperature process as the instruments capable of measuring fluid flow cannot survive the medium inside the reactor. However, computational fluid dynamics (CFD) can provide an insight into the flow, where experimental access is limited or not possible. This paper presents a CFD analysis for directly irradiated solar thermochemical reactor to characterize the influence of flow behavior on the heat transfer and solar cracking process. The heat transfer by radiation from carbon particles is considered by providing global absorption and scattering coefficients in the computational domain obtained from Mie code. The flow field is based on RNG k–? model derived using renormalization group theory. This technique accounts for the effect of swirl on turbulence thereby enhancing accuracy for the swirl flows. Validation of the numerical results is carried out by making a comparison with the experimental results. Highlighting the effects of carving on the solar reactor walls, this study presents numerical analyses of solar reactor geometry for two cases; namely, when there is no vortex forming carving in the cavity, and when there is vortex forming helical carving. The results show that carving has significant influence on the flow behavior, however, it has very little effect on the outlet temperature. The numerical results also show that the radiative heat transfer mechanism is the dominant means of heat transfer compared to the effects of conduction and convection.     

Natural contamination of cyclopiazonic acid in dried figs and co-occurrence of aflatoxin

Natural cyclopiazonic acid (CPA) and aflatoxin (AF) contamination were investigated in Aspergillus section Flavi positive dried fig samples collected from orchards after harvesting. Cyclopiazonic acid and AF were determined by thin layer chromatography (TLC) and high performance liquid chromatography (HPLC), respectively. Cyclopiazonic acid was found in all samples of dried figs that contain AF. Cyclopiazonic acid and AF co-occurred in 23% of the samples. The number of dried fig samples contaminated with CPA was higher than the samples containing AF. Therefore CPA was a more common mycotoxin than AF in dried figs. To the best of our knowledge, this is the first report of CPA and co-occurrence of CPA and AF in dried figs.     

Supply chain reengineering in a paint company using axiomatic design

The purpose of this paper is to outline the importance and benefits an organization can achieve through using a decomposition-based decision-making tool incorporating supply chain-balanced scorecard performance measures for supply chain reengineering. An axiomatic design-based model built on the insights gained from supply chain performance measures and reengineering model is applied to a paint company. The model aids supply chain reengineering by identifying the scope of the reengineering design. The resultant reengineering design based on the needs and strategies of the firm in question is presented. A thorough simulation study follows to impart substantial improvements. The case displays how the model can help companies adopt a more structured approach to the complicated problem of supply chain reengineering. This paper focuses on supply chain reengineering models where no conclusive work exists and is expected to fill a gap in the area and be instrumental to both researchers and practitioners by providing a direction for coherent decision making on supply chain reengineering studies.     

A multilayer tissue engineered meniscus substitute

Various methods have been tried to treat the main meniscus problem, meniscal tears, for which we believe tissue engineering could be a viable solution. In this study, a three dimensional, collagen-based meniscus substitute was prepared by tissue engineering using human fibrochondrocytes and a collagen based-scaffold. This construct was made with 3 different collagen-based foams interspaced with two electrospun nano/microfibrous mats. The top layer was made of collagen type I–chondroitin sulfate–hyaluronic acid (Coll–CS–HA), and the middle and the bottom layers were made of only collagen type I with different porosities and thus with different mechanical properties. The mats of aligned fibers were a blend of collagen type I and poly(l-lactic acid-co-glycolic acid) (PLGA). After seeding with human fibrochondrocytes, cell attachment, proliferation, and production of extracellular matrix and glucoseaminoglycan were studied. Cell seeding had a positive effect on the compressive properties of foams and the 3D construct. The 3D construct with all its 5 layers had better mechanical properties than the individual foams.     

Block copolymers of acrylonitrile and poly(dimethylsiloxane)s

The chemical redox system of ceric ammonium nitrate(Ce⁴⁺) and poly(dimethylsiloxane)s (PDMS) with monohydroxy (MH), dihydroxy (DH), and diamine(DA) chain ends was used to polymerize acrylonitrile (AN) to produce monohydroxy poly(dimethylsiloxane)s‐b‐polyacrylonitrile (MH.PDMS‐b‐PAN), dihydroxy poly(dimethylsiloxane)s‐b‐polyacrylonitrile (DH.PDMS‐b‐PAN), and α, ω‐diamine poly(dimethylsiloxane)s‐b‐polyacrylonitrile (DA.PDMS‐b‐PAN) block copolymers. The concentration, reaction time, and the type of poly(dimethylsiloxane) affect the yield and the molecular weight of the copolymers. The ratio of AN/ceric salt/PDMS has remarkably affects the properties of formed copolymers. DH.PDMS‐b‐PAN copolymers were also prepared by electroinduced polymerization in the presence of catalytic amount of Ce⁴⁺ in a divided electrochemical cell where Ce³⁺ is readily oxidized into Ce⁴⁺ at the anode. The products were characterized by Fourier transform infrared spectroscopy, ¹H‐NMR spectroscopy, DSC, and their surface properties were investigated through contact‐angle measurements. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013