Effect of modified starch from sweet potato as a fat replacer on the quality of reduced fat ice creams

In the present study, application of different levels (0, 1 and 2%) of citric acid treated sweet potato starch as a fat replacer (FR) in a high (11% fat), medium (6% fat) and low-fat (1%) ice creams were investigated. Results indicated that hardness value tends to improve with the addition of 1% FR in all reduced fat ice creams. During 60 days of storage, a decreasing trend was noticed in overrun, acidity and hardness values of ice cream samples. Overall score of sensory conveyed that the reduced fat ice creams with 1% FR (medium fat ice cream and low fat ice cream) were found to be very acceptable by sensory panels with a similar physicochemical characteristics and acceptance as high-fat ice cream (control) at the end of storage period. Citric acid treated sweet potato starch proved to be a promising alternative as a fat replacer in the ice cream production.     

Electrodeposition of amorphous silicon anode for lithium ion batteries

Amorphous silicon has been successfully electrodeposited on copper using a SiCl₄ based organic electrolyte under galvanostatic conditions. The electrodeposited silicon films were characterized for their composition, morphology and structural characteristics using glancing angle X-ray diffraction (GAXRD), scanning electron microscopy (SEM), and Raman spectroscopy. GAXRD and Raman analyses clearly confirm the amorphous state of the deposited silicon film. The deposited films were tested for possible application as anodes for Li-ion battery. The results indicate that this binder free amorphous silicon anode exhibits a reversible capacity of ∼1300 mAh g⁻¹ with a columbic efficiency of >99.5% up to 100 cycles. Impedance measurements at the end of each charge cycle show a non-variable charge transfer resistance which contributes to the excellent cyclability over 100 cycles observed for the films. This approach of developing thin amorphous silicon films directly on copper eliminates the use of binders and conducting additives, rendering the process simple, facile and easily amenable for large scale manufacturing.     

Ultrasmall microlens array based on vertically aligned carbon nanofibers

An ultrasmall tunable microlens with a diameter of 1.5 μm is fabricated using nematic liquid crystals (electrically tunable medium) and vertically aligned carbon nanofibers (CNFs, electrodes). Individual CNFs are grown at the center of circular dielectric regions. This allows the CNFs to produce a more Gaussian electric field profile and hence more uniformity in lens array switching.     

Recent progress on the synthesis and applications of carbon based nanostructures

This article reviews the latest developments in the synthesis of Graphene, Carbon nanotubes and graphene/CNT based devices based on patents, patent applications and articles published in the last two years. A brief introduction about CNT and Graphene is presented, followed by the latest techniques and advanced processing for the large scale synthesis of Graphene and CNTs. Furthermore, a brief account of emerging devices based on applications of CNTs and graphene not limited to sensors, high speed electronics, energy harvesting and storage applications are presented.     

Aqueous slurry processing of monolithic films for SOFC - YSZ, LSM and YSZ-NiO systems

The powder precursor for yttria stabilized zirconia (YSZ) was prepared by reverse strike co-precipitation method while those for lanthanum strontium manganite (LSM) and nickel oxide (NiO) were prepared by gel combustion method. The thermal decomposition and phase evolution behavior of these powder precursors was carried out by thermogravimetry and XRD. Phase pure cubic YSZ formed around 430 °C from the dried amorphous gel and exhibited a mass loss of 23%. Even though the as formed LSM and NiO precursors exhibited nano-crystallinity, they contained some amount of volatiles (up to 8%), elimination of which required a post heat treatment. The optimum calcination temperature for these powders to obtain sintered bodies with desired densities (viz. >95% T.D. for YSZ and 65-75% T.D. for LSM, YSZ-NiO) at the desired sintering temperatures (1350, 1400 and 1500 °C respectively), was found to vary in the range of 900 1350 °C. Fine YSZ powder with size (D₅₀) 0.7-1.2 μm was used in formation of the electrolyte film while YSZ, LSM and NiO powder with size (D₅₀) 3-5 μm along with carbon pore former (15 wt% in LSM) were used for formation of electrode films. The conditions for slurry formation for film casting were evaluated through surface charge and rheological studies. The study of the effect of pH of aqueous suspension on zeta potential showed that YSZ and NiO were charged to sufficient extent (>20 mV) in both acidic and alkaline media while LSM and pore former exhibited sufficient surface charging only in alkaline medium. The slurries for tape casting were formulated using a polyvinyl binder solution and the composition was optimized through rheological studies. Compositions were fixed to form slurries with desired amount of pseudo-plasticity that could exhibit controlled flow to form flexible films with desirable thickness. The process conditions were optimized to form flat sintered electrolyte films possessing about 95% T.D. and electrode films possessing 65-75% T.D. Sintered bodies of the electrolytes exhibited fine-grained microstructure while the electrodes exhibited composite structure of grains and inter-connected pores.     

Photon-assisted synthesis of ultra-thin yttria-doped zirconia membranes: Structure, variable temperature conductivity and micro-fuel cell devices

We report on the synthesis and functional properties of nanoscale (50 nm) dense Y-doped zirconia (YDZ) electrolyte thin films by photon-assisted oxidation of Zr–Y precursor alloy thin films. Crystalline zirconia films with grain size of 5 nm were successfully grown at room temperature by oxidation under ultra-violet (UV) photon irradiation. Microstructure of the films was characterized by transmission electron microscopy. The electrochemical conductivity of UV grown YDZ electrolytes was investigated over a broad range of temperatures using Pt electrodes as a function of yttria doping concentration. The slightly lower electrical conductivity in UV grown films at intermediate temperature range (400–550 °C) is consistent with previous reports on oxygen defect annihilation under photo-excitation. Micro-fuel cells utilizing such ultra-thin YDZ membranes yielded 12 mW cm⁻² power density at 550 °C. The results are of potential relevance in advancing low temperature ultra-thin oxide membrane synthesis for energy applications.     

Hydrous RuO(2)-Carbon Nanofiber electrodes with high mass and electrode-specific capacitance for efficient energy storage

We demonstrate a new strategy for the fabrication of supercapacitor electrodes possessing high mass and area-specific capacitance for efficient charge storage, which can be extremely useful for the development of light, compact and high performance supercapacitors for a variety of high power demanding applications. High mass and electrode area specific capacitances were attained by using Hydrous Ruthenium Oxide (HRO)-Carbon Nanofiber (CNF) hybrid electrodes prepared by the deposition of HRO (~31% Ru content) on both the outer and inner surfaces of a cylindrical hollow CNF having open tips. Electrochemical studies of the uniformly deposited HRO nanoparticles on the CNF surface showed a mass specific capacitance of 645 F g(-1) and an electrode specific capacitance of 1.29 F cm(-2) with a HRO-CNF material loading of 2 mg cm(-2) in the supercapacitor electrodes. The mass specific capacitance of pure HRO is 301 F g(-1), whereas the mass specific capacitance of HRO in the HRO-CNF electrode is ~1300 F g(-1), which is very close to the theoretical capacitance of HRO. This enhanced charge storage ability, high rate capability, better cyclic stability and low ESR of the HRO-CNF will be useful for the development of high performance supercapacitors.