Nanomaterials based biofuel cells: A review

Biofuel cells (BFCs) are the devices made to transform the chemical energy of organic matter to electrical energy utilizing metabolic reactions occurring in microorganisms during degradation of organic contaminants. In spite of having many applications such as waste water treatment, biosensors and portable uses of BFCs, promoting the uses of BFCs is very challenging because of short life-time and low-power density. Most of the BFC developed till date is only capable to fulfill energy needs of biomedical short-term implanted devices. Use of materials with nano dimensions in the construction of BFCs has been studied extensively and reported as a worthwhile strategy to increase its efficiency. Usually, it is difficult to achieve efficient electron transfer on planar electrode from biocatalyst due to its non-specific orientational the interface. Nonmaterials provide close wiring for the electron transfer between biocatalyst and electrode. Use of various nanomaterials is the most effective way to decrease the gap between active sites (electron producing area)deep inside the enzyme or proteins and the electrodes to achieve better electron transfer. Also, various nanomaterials are utilized to improve the membrane materials for better electron barrier. Many carbon nanostructures, conducting polymers, metal and metal oxides are promising nonmaterials to enhance the current output from BFC. This review highlights recent progress registered in the development of various nanomaterials for construction of electrode and membranes of biofuel cells for better efficiency. It also emphasized the utilization of different metallic nanomaterials, inorganic nanomaterials, conducting polymer-based nanomaterials and carbon-based nanomaterials such as graphene, fullerenes, and carbon nanotubes.     

Structural development and magnetic phenomenon in Zn–Cr–Fe multi oxide nano-crystals

The Cr³⁺ ions doped multi-oxide ZnFe_2−xCr_xO₄ ferrite nanoparticles have been synthesized by chemical co-precipitation method. Site occupancies of Zn²⁺, Cr³⁺ and Fe³⁺ ions were analyzed using X-ray diffraction data and Buerger's method. The effect of the constituent phase variation on the magnetic hysteresis behavior was examined by saturation magnetization which decreases with the increase in Cr³⁺ content in place of Fe³⁺ ions at octahedral B-site. Typical blocking temperature (T_B) around 90 K was observed by zero field cooling and field cooling magnetization study. Room temperature Mössbauer spectra show two paramagnetic doublets (tetrahedral and octahedral sites). The isomer shifts of both doublets decrease whereas quadrupole splitting and relative area of tetrahedral A-site increases with increasing Cr³⁺ substitution. The dielectric constant (measured on compositions x=0, 0.4, 0.8 and 1.0) increases when the temperature increases as in the semiconductor. This behavior is attributed to the hopping of electrons between Fe²⁺ and Fe³⁺ ions with a thermal activation.     

A novel leukodepletion filter from electrospun poly(ethylene-vinyl alcohol) membranes and evaluation of its efficiency

The authors describe the fabrication and evaluation of a novel leukodepletion filter using novel poly(ethylene-vinyl alcohol) membranes through electrospinning. The membranes were biocompatible and nonhemolytic. A prototype of the filter was developed by stacking the membranes in a poly(methyl methacrylate) case. Upon whole blood filtration, the filter could achieve 100% leukodepletion while capturing 8% red blood cells and 91% platelets. The length of filtration through the developed filter was high when compared to that of marketed filter while overall performance of the filter was comparable to that of the marketed filter.     

Effect of Duplex Ageing on the Properties of A356 Alloy Containing Rare Earth Elements

Reduced weight of automobiles for the purpose of fuel economy has encouraged the use of light metals especially aluminium alloys. A356 Al alloy containing 7% Si and 0.3% Mg is widely used in automobile and aircraft industries due to excellent castability, good corrosion resistance and good pressure tightness. A356 is age hardenable alloy and there is appreciable improvement in strength and hardness achievable due to precipitation of intermetallic compound Mg₂Si. In the present investigation, aluminium alloy A356 with and without rare earth (RE) addition (0.5 wt%) was subjected to single ageing as well as double aging treatment. The results were compared for mechanical properties like hardness and ultimate tensile strength with the material not containing RE additions.     

Crystallinity,conductivity, and magnetic properties of PVDF‐Fe3O4 composite films

The formation of Fe₃O₄ nanoparticles by hydrothermal process has been studied. X‐ray Diffraction measurements were carried out to distinguish between the phases formed during the synthesis. Using the synthesized Fe₃O₄ nanoparticles, poly(vinyledene fluoride)‐Fe₃O₄ composite films were prepared by spin coating method. Scanning electron microscopy of the composite films showed the presence of Fe₃O₄ nanoparticles in the form of aggregates on the surface and inside of the porous polymer matrix. Differential Scanning calorimetry revealed that the crystallinity of PVDF decreased with the addition of Fe₃O₄. The conductitivity of the composite films was strongly influenced by the Fe₃O₄ content; conductivity increased with increase in Fe₃O₄ content. Vibration sample magnetometry results revealed the ferromagnetic behavior of the synthesized iron oxide nanoparticles with a Ms value of 74.50 emu/g. Also the presence of Fe₃O₄ nanoparticles rendered the composite films magnetic. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Interleukin-1 Receptor Antagonist Reduces Neonatal Lipopolysaccharide-Induced Long-Lasting Neurobehavioral Deficits and Dopaminergic Neuronal Injury in Adult Rats

Our previous study showed that a single lipopolysaccharide (LPS) treatment to neonatal rats could induce a long-lasting neuroinflammatory response and dopaminergic system injury late in life. This is evidenced by a sustained activation of microglia and elevated interleukin-1β (IL-1β) levels, as well as reduced tyrosine hydroxylase (TH) expression in the substantia nigra (SN) of P70 rat brain. The object of the current study was to test whether co-administration of IL-1 receptor antagonist (IL-1ra) protects against LPS-induced neurological dysfunction later in life. LPS (1 mg/kg) with or without IL-1ra (0.1 mg/kg), or sterile saline was injected intracerebrally into postnatal day 5 (P5) Sprague-Dawley male rat pups. Motor behavioral tests were carried out from P7 to P70 with subsequent examination of brain injury. Our results showed that neonatal administration of IL-1ra significantly attenuated LPS-induced motor behavioral deficits, loss of TH immunoreactive neurons, as well as microglia activation in the SN of P70 rats. These data suggest that IL-1β may play a pivotal role in mediating a chronic neuroinflammation status by a single LPS exposure in early postnatal life, and blockading IL-1β might be a novel approach to protect the dopaminergic system against perinatal infection/inflammation exposure.     

A selection of material using a novel type decision-making method: Preference selection index method

The aim of the current study is to implement a novel tool to help the decision-maker for selection of a proper material that will meet all the requirements of the design engineers. Preference selection index (PSI) method is a novel tool to select best alternative from given alternatives without deciding relative importance between attributes. In the present study, three different types of material selection problems are examined. A validation and consistency test of preference selection index method is performed in present work by comparing results of PSI method with published results of graph theory and matrix approach (GTMA), and technique for order preference by similarity to ideal solution (TOPSIS) method, respectively. The research has concluded that the PSI method is logical and more appropriate for the material selection problems.