Electrodeposition of palladium-dotted nickel nanowire networks as a robust self-supported methanol electrooxidation catalyst

Journal of Materials Science - Mass activity and long-term stability are two major issues in current fuel cell catalyst designs. While supported catalysts normally suffer from poor long-term...     

ICT for socio-economic development: A citizens’ perspective

There is a widespread belief that information and communication technologies (ICTs) can play a significant role in the socio-economic development of a developing country. ICT has the potential to affect many aspects of economic and societal activities such as GDP growth, employment, productivity, poverty alleviation, quality of life, education, and healthcare. While the literature provides a myriad of definitions and elements of socio-economic development, the focus tends to be on theoretical conceptualizations from various disciplines and impacts from isolated individual projects. In particular, the impact of ICT on socio-economic development has not been carefully examined from the viewpoint of the ultimate stakeholder, the citizens of a country, who are the final consumers of the technology. This study fills this gap by focusing on the citizens’ view in describing ICT-driven socio-economic development in a developing country. A theoretical framework influenced by the “capabilities approach” was developed to guide this research, and the interpretive stance was used to conduct the study. More specifically, the narrative research method, which is seldom used in IS research but is appropriate for this study, was used. Narratives allow deeper and profound insights into social representations and participants' beliefs about the role of ICT in socio-economic development. Using this methodology, a model of the impact dimensions of socio-economic development is presented.     

Importance of satellite-retrieved rain/no-rain information on short-range weather predictions

The impact of assimilating rain (satellite-retrieved rainfall is greater than zero) and no-rain (satellite-retrieved rainfall is equal to zero) information retrieved from the Tropical Rainfall Measuring Mission (TRMM) 3B42 precipitation is assessed during Indian summer monsoon 2013 using the weather research and forecasting (WRF) model. Daily three parallel experiments are performed with and without satellite rainfall assimilation for short-range weather forecasts. Additional two experiments are performed daily to evaluate the sensitivity of cumulus parameterization on the WRF model predictions when precipitations are used for assimilation. Precipitation assimilation improves the 48 h low-level temperature, moisture, and winds predictions. Rainfall prediction is also improved over central India when satellite-retrieved rainfall information are assimilated compared to without rainfall assimilation (CNT) experiments. More improvements are seen in moisture forecasts when the Kain–Fritsch (KF) cumulus convection parameterization scheme is used against the Grell–Devenyi ensemble (GD) scheme, whereas for temperature and wind speed forecasts the Grell convection parameterization scheme performed better over the Indian region. Overall, precipitation assimilation improved the WRF model analysis and subsequent model forecasts compared with without precipitation assimilation experiments. Results show that no-rain observations also have a significant positive impact on short-range weather forecasts.     

Synthesis of novel sulfonium salts and cationic polymerization of epoxides and vinyl ether

Novel 1‐methoxycarbonylethylmethylphenylsulfonium salts with nonnucleophilic anions, namely, hexafluorophosphate, hexafluoroantimonate, and tetrafluoroborate, were synthesized by the reaction of 1‐methoxycarbonylethylphenylsulfide and dimethyl sulfate followed by anion exchange with potassium hexafluorophosphate, sodium hexafluoroantimonate, and sodium tetrafluoroborate, respectively. The cationic polymerization (photopolymerization and thermal polymerization) of epoxy and vinyl ether monomers was carried out to demonstrate the applicability of the newly synthesized sulfonium salts. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3157–3163, 2007     

An approach to eliminate stepped features in multistage incremental sheet forming process: Experimental and FEA analysis

Incremental sheet forming (ISF) is a recently developed manufacturing technique. In ISF, forming is done by applying deformation force through the motion of Numerically controlled (NC) single point forming tool on the clamped sheet metal blank. Single Point Incremental sheet forming (SPISF) is also known as a die-less forming process because no die is required to fabricate any component by using this process. Now a day it is widely accepted for rapid manufacturing of sheet metal components. The formability of SPISF process improves by adding some intermediate stages into it, which is known as Multi-stage SPISF (MSPISF) process. However during forming in MSPISF process because of intermediate stages stepped features are generated. This paper investigates the generation of stepped features with simulation and experimental results. An effective MSPISF strategy is proposed to remove or eliminate this generated undesirable stepped features.     

A universal two-way approach for estimating unknown frequencies for unknown number of sinusoids in a signal based on eigenspace analysis of Hankel matrix

We develop a novel approach to estimate the \(n\) unknown constituent frequencies of a noiseless signal that comprises of unknown number, \(n\), of sinusoids of unknown phases and unknown amplitudes. The new two-way approach uses two constraints to accurately estimate the unknown frequencies of the sinusoidal components in a signal. The new approach serves as a verification test for the estimated unknown frequencies through the estimated count of the unknown number of frequencies. The Hankel matrix, of the time domain samples of the signal, is used as a basis for further analysis in the Pisarenko harmonic decomposition. The new constraints, the existence factor and the component factor, have been introduced in the methodology based on the relationships between the components of the sinusoidal signal and the eigenspace of the Hankel matrix. The performance of the developed approach has been tested to correctly estimate any number of frequencies within a signal with or without a fixed unknown bias. The method has also been tested to accurately estimate the very closely spaced low frequencies.     

Theory and practice of ubiquitous quantitative chemical analysis using conventional computer optical disk drives

We demonstrate a new attractive approach for ubiquitous quantitative chemical or biological sensing when analog signals are acquired from conventional optical disk drives, and these signals are used for quantitative detection of optical changes of sensing films deposited on conventional CD and DVD optical disks. Our developed analytical model of the operation of this Lab-on-DVD system describes the optical response of sensing films deposited onto the read surface of optical disks by taking into account the practical aspects of system performance that include possible reagent leaching effects, water sampling (delivering) efficiency, and possible changes of the film morphology after water removal. By applying a screen-printing process, we demonstrated a laboratory-scale automated production of sensing films with an average thickness of approximately 10 microm and a thickness relative standard deviation of <3% across multiple films. Finally, we developed a system for delivery of water-sample volumes to sensing films on the disk that utilized a multifunctional jewel case assembly.     

The effect of plasmon field on the coherent lattice phonon oscillation in electron-beam fabricated gold nanoparticle pairs

By using electron beam lithography, we fabricated pairs of gold nanoparticles with varying interparticle separation. Double-beam femtosecond transient absorption spectroscopy was used to determine the coherent lattice oscillation frequency as a function of the interparticle separation in the presence of the plasmon field excited by the monitoring probe light. We found that the fractional shift in the coherent lattice phonon oscillation frequency follows an exponential decay with respect to the interparticle gap scaled by the disc diameter with the same decay constant as that previously observed for the fractional shift in the surface plasmon electronic oscillation resonance frequency. This strongly suggests that it is the near-field coupling between the particles that shifts both the coherent electronic oscillation (plasmon) frequency and the coherent lattice oscillation (phonon) frequency. The similar trend in the effect of interparticle coupling on the plasmon frequency and the phonon frequency is essentially a reflection of the universal scaling behavior of the distance decay of the interparticle plasmonic near-field. It is shown that the observed decrease in the lattice oscillation frequency with decrease in the interparticle distance is the result of a reduction in the effective free electron density within each nanoparticle pair partner as a result of the polarizing perturbation of the plasmonic field of the other nanoparticle in the pair.     

Method for measuring thickness of dielectric films using microdielectric fringe-effect sensors

A method for noninvasive thickness measurements of dielectric films using fringe-effect (FE) sensors is developed and experimentally validated. The fringing electrical field, created by electrodes microfabricated at the film substrate, depends on the film thickness and dielectric permittivity of the film under test (FUT). The unknown film thickness is estimated by matching the theoretical prediction of thickness-dependent sensor admittance with the measured value. In the case of FE sensors with spatially periodic, interdigitated electrode (IDE) configuration, the admittance prediction is simplified, which allows for the real-time measurements of changing thickness. The developed method can be used to continuously measure the changing dielectric permittivity of the FUT material, which makes it possible to determine the thickness of films of changing dielectric properties, caused by chemical or other transformations. The application of the developed method is demonstrated experimentally by measuring the thickness of silicon nitride film deposited in several increments on the quartz substrate of the IDE sensor. In the expected range of sensor sensitivity, the results show an excellent agreement with the independent thickness measurements.