Novel inorganic precursors [Co4.32Zn1.68(HCO2)18(C2H8N)6]/SiO2 and Co4.32Zn1.68(HCO2)18(C2H8N)6]/Al2O3 for Fischer–Tropsch synthesis

The silica- and alumina-supported Co–Zn catalysts were synthesized by thermal decomposition of new inorganic precursors [Co_4.32Zn_1.68(HCO₂)₁₈(C₂H₈N)₆]/SiO₂ or Al₂O₃. A novel coordination polymer formulated as [Co_4.32Zn_1.68(HCO₂)₁₈(C₂H₈N)₆] (1) was prepared using the solvothermal technique and characterized by elemental analysis, FT-infrared spectroscopy. Thermal stability of the complex 1 was investigated by thermogravimetric analysis and differential scanning calorimetry, and its structure was determined by single-crystal X-ray diffraction. Characterization of catalysts was carried out using powder X-ray diffraction (XRD), scanning electron microscopy (SEM), and BET specific surface area. The catalysts were evaluated for Fischer–Tropsch synthesis (FTS) in the temperature range 200–300 °C. The results revealed that the synthesized catalysts have higher selectivity to the desired products at 260 °C. The performance of the catalysts was compared to those of catalysts constructed via impregnation method and the fabricated catalysts show higher activity and selectivity than the reference catalysts.     

Development of La-impregnated TiO2 based ethanol sensors for next generation automobile application

Journal of Materials Science: Materials in Electronics - Bio-fuel, a blend of ethanol (~?10 to 85%) and gasoline with various compositions, is one of the promising next generation energy...     

Microstructure Optimization in Fuel Cell Electrodes using Materials Design

A multiscale model based on statistical continuum mechanics is proposed to predict the mechanical and electrical properties of heterogeneous porous media. This model is applied within the framework of microstructure sensitive design (MSD) to guide the design of the microstructure in porous lanthanum strontium manganite (LSM) fuel cell electrode. To satisfy the property requirement and compatibility, porosity and its distribution can be adjusted under the guidance of MSD to achieve optimized microstructure.     

A comprehensive two dimensional analytical study of a nanoscale linearly graded binary metal alloy gate cylindrical junctionless MOSFET for improved short channel performance

Over the years, the approach of cylindrical gate MOSFETs has attracted several research initiatives due to the very inherent benefit of the cylindrical geometry over other conventional planar structures. Nowadays, the present boon in the research field of nanoscale device physics is attributed to a large extent by the development of junctionless devices. In our current research endeavor, we have for the first time proposed a new idea by incorporating the innovative concept of work function engineering by the continuous horizontal variation of mole fraction in a binary metal alloy gate into a junctionless cylindrical gate MOS structure, thereby presenting a new device structure, a junctionless work function engineered gate cylindrical gate MOSFET (JL WFEG CG MOSFET). We have presented a rigorous analytical modeling of the proposed JL WFEG CG MOS structure by solving the two dimensional Poisson’s equation in cylindrical co-ordinates. Based on this analytical modeling, an overall performance comparison of the proposed JL WFEG CG MOS and normal JL CG MOS structure has been investigated in order to testify the improved performance of the proposed JL WFEG CG structure over its normal JL CG equivalent in terms of reduced short channel effects, threshold voltage roll off, drain induced barrier lowering and superior current driving capability. The results obtained from our analytical analysis are found to be in good agreement with the simulation results, thereby establishing the accuracy of our modeling.     

Assembly of layered double hydroxide on multi‐walled carbon nanotubes as reinforcing hybrid nanofiller in thermoplastic polyurethane/nitrile butadiene rubber blends

An efficient approach has been applied to assemble MgAl layered double hydroxide onto pristine carbon nanotubes using sodium dodecylsulfate. The assembling process and formation of such hybrid nanostructures were established using X‐ray diffraction, Fourier transform infrared spectroscopy, field emission scanning electron microscopy and high‐resolution transmission electron microscopy. Subsequently, the hybrid was used as nanofiller in the development of high‐performance thermoplastic polyurethane/acrylonitrile butadiene rubber (1:1 w/w) blend nanocomposites. Measurements of mechanical and dynamic mechanical properties show that tensile strength, elongation at break and storage modulus improve significantly by 171%, 1.8 times and 241% in a blend with 0.50 wt% loading of hybrid filler. Thermogravimetric analysis shows that the thermal stability of the blend with 0.50 wt% hybrid filler compared to neat material is maximally improved by 20 °C determined at 50% weight loss. Differential scanning calorimetry shows the maximum enhancement in melting temperature (7 °C) and crystallization temperature (31 °C) due to significant nucleation efficiency of the filler, homogeneous dispersion and strong interfacial interaction between polymer matrix and filler. © 2015 Society of Chemical Industry     

Montmorillonite–multiwalled carbon nanotube nanoarchitecture reinforced thermoplastic polyurethane

Montmorillonite (MMT)–multiwalled carbon nanotube (MWCNT) hybrids were prepared in different weight ratios by simple dry grinding method and characterized. Subsequently, MMT–MWCNT (1:1) hybrid was used as reinforcing filler in developing thermoplastic polyurethane (TPU) nanocomposites by solution blending method. Thermogravimetric analysis showed that 0.25 wt% hybrid‐loaded TPU nanocomposite exhibited maximum enhancement of 31°C corresponding to 50 wt% loss in thermal stability when compared with neat TPU. Differential scanning calorimetry of this composite also indicated that its crystallization and melting temperatures are enhanced by 37 and 13°C, respectively. Mechanical data showed that tensile strength and Young's modulus of 0.50 wt% filled TPU were maximum improved by 57 and 87.5%, respectively. Dynamic mechanical analysis (DMA) measurements indicated 174% (50°C) improvement in storage modulus of 0.50 wt% hybrid‐loaded TPU. Such improvements in thermal and mechanical properties have been attributed to homogeneous dispersion, strong interfacial interaction, and synergistic effect. POLYM. COMPOS., 37:1775–1785, 2016. © 2014 Society of Plastics Engineers     

Tuning the pH Response of i‐Motif DNA Oligonucleotides

Cytosine‐rich single‐stranded DNA oligonucleotides are able to adopt an i‐motif conformation, a four‐stranded structure, near a pH of 6. This unique pH‐dependent conformational switch is reversible and hence can be controlled by changing the pH. Here, we show that the pH response range of the human telomeric i‐motif can be shifted towards more basic pH values by introducing 5‐methylcytidines (5‐MeC) and towards more acidic pH values by introducing 5‐bromocytidines (5‐BrC). No thermal destabilisation was observed in these chemically modified i‐motif sequences. The time required to attain the new conformation in response to sudden pH changes was slow for all investigated sequences but was found to be ten times faster in the 5‐BrC derivative of the i‐motif.     

THERMOELASTIC BUCKLING OF ISOTROPIC AND ORTHOTROPIC PLATES WITH IMPERFECTIONS

The nonlinear strain-displacement relations for thin orthotropic plates are considered and substituted into the potential energy function of thermoelastic loadings. The Euler equations are then applied to the functional of energy, and the general thermoelastic equations of thin orthotropic plates are obtained. The stability equations are then derived through the second variation of the potential energy function. The thermal loadings include the uniform temperature rise, axial temperature difference, and the gradient temperature through the thickness. The thermoelastic buckling of a thin plate under these thermal loadings is investigated. The results are extended to isotropic and orthotropic thin plates with and without imperfections.     

Analytical modeling and simulation of a linearly graded binary metal alloy gate nanoscale cylindrical MOSFET for reduced short channel effects

In the present era of miniaturization and low power devices, the approach of cylindrical gate MOS structure is in vogue among the researchers for enhancing the performance of nanoscale MOSFETs due to the inherent advantage of the cylindrical geometry compared to the conventional planar structures. In this work, for the first time, the innovative concept of work function engineering by the continuous horizontal variation of mole fraction in a binary metal alloy gate has been incorporated in a cylindrical MOS and a new structure, the work function engineered gate cylindrical gate MOSFET (WFEG CG MOSFET) has been proposed. A detailed analytical modeling of this novel WFEG CG MOS structure has been presented based on the solution of two dimensional Poisson’s equation in cylindrical coordinates. An overall performance comparison of the WFEG CG MOS and normal CG MOSFET has been investigated to establish the superiority of the proposed WFEG structure over its normal CG counterpart in terms of increased immunity against short channel effects, reduced value of drain induced barrier lowering and enhanced current driving capability. The results of our analytical modeling are found to be in good agreement with the simulation results, thereby establishing the accuracy of our modeling.