Solvothermal synthesis of high-performance Ni-Co layered double hydroxide nanofoam electrode for electrochemical energy storage

Patel, R.,Inamdar, A.I.,Hou, B.,Cha, S.,Ansari, A.T.,Gunjakar, J.L.,Im, H.,Kim, H. ELSEVIER 2017 Current Applied Physics Vol.17 No.4

<P>A nanofoam nickel cobalt layered double hydroxide (NiCo(OH)(2)) electrode film is fabricated on a stainless-steel substrate with the use of a simple one-step solvothermal process. The nanofoam NiCo(OH)(2) electrode exhibits a high specific capacitance of 2710.2 Fig at a current density.of 9.1 A/g, and a good capacity retention of similar to 70% after 2000 charge-discharge cycles at a high current density of 31.8 A/g. An energy density of 60.23 Wh/kg is obtained at a power density of 1.8 kW/kg. The excellent electrochemical energy storage performance of the NiCo(OH)(2) electrode is due to the synergetic effect of a significantly improved ionic diffusion and an effective charge transfer, which is linked to a well-dispersed interconnected nanofoam morphology and binder-free direct contact with the current collector. (C) 2017 Elsevier B.V. All rights reserved.</P>

Spectroscopic needs for imaging dark energy experiments

Newman, J.A.,Abate, A.,Abdalla, F.B.,Allam, S.,Allen, S.W.,Ansari, R.,Bailey, S.,Barkhouse, W.A.,Beers, T.C.,Blanton, M.R.,Brodwin, M.,Brownstein, J.R.,Brunner, R.J.,Carrasco Kind, M.,Cervantes-Cota, North-Holland 2015 Astroparticle physics Vol.63 No.-

Ongoing and near-future imaging-based dark energy experiments are critically dependent upon photometric redshifts (a.k.a. photo-z's): i.e., estimates of the redshifts of objects based only on flux information obtained through broad filters. Higher-quality, lower-scatter photo-z's will result in smaller random errors on cosmological parameters; while systematic errors in photometric redshift estimates, if not constrained, may dominate all other uncertainties from these experiments. The desired optimization and calibration is dependent upon spectroscopic measurements for secure redshift information; this is the key application of galaxy spectroscopy for imaging-based dark energy experiments. Hence, to achieve their full potential, imaging-based experiments will require large sets of objects with spectroscopically-determined redshifts, for two purposes:*Training: Objects with known redshift are needed to map out the relationship between object color and z (or, equivalently, to determine empirically-calibrated templates describing the rest-frame spectra of the full range of galaxies, which may be used to predict the color-z relation). The ultimate goal of training is to minimize each moment of the distribution of differences between photometric redshift estimates and the true redshifts of objects, making the relationship between them as tight as possible. The larger and more complete our ''training set'' of spectroscopic redshifts is, the smaller the RMS photo-z errors should be, increasing the constraining power of imaging experiments. Requirements: Spectroscopic redshift measurements for ~30,000 objects over >~15 widely-separated regions, each at least ~20arcmin in diameter, and reaching the faintest objects used in a given experiment, will likely be necessary if photometric redshifts are to be trained and calibrated with conventional techniques. Larger, more complete samples (i.e., with longer exposure times) can improve photo-z algorithms and reduce scatter further, enhancing the science return from planned experiments greatly (increasing the Dark Energy Task Force figure of merit by up to ~50%). Options: This spectroscopy will most efficiently be done by covering as much of the optical and near-infrared spectrum as possible at modestly high spectral resolution (λ/Δλ>~3000), while maximizing the telescope collecting area, field of view on the sky, and multiplexing of simultaneous spectra. The most efficient instrument for this would likely be either the proposed GMACS/MANIFEST spectrograph for the Giant Magellan Telescope or the OPTIMOS spectrograph for the European Extremely Large Telescope, depending on actual properties when built. The PFS spectrograph at Subaru would be next best and available considerably earlier, c. 2018; the proposed ngCFHT and SSST telescopes would have similar capabilities but start later. Other key options, in order of increasing total time required, are the WFOS spectrograph at TMT, MOONS at the VLT, and DESI at the Mayall 4m telescope (or the similar 4MOST and WEAVE projects); of these, only DESI, MOONS, and PFS are expected to be available before 2020. Table 2-3 of this white paper summarizes the observation time required at each facility for strawman training samples. To attain secure redshift measurements for a high fraction of targeted objects and cover the full redshift span of future experiments, additional near-infrared spectroscopy will also be required; this is best done from space, particularly with WFIRST-2.4 and JWST. Calibration: The first several moments of redshift distributions (the mean, RMS redshift dispersion, etc.), must be known to high accuracy for cosmological constraints not to be systematics-dominated (equivalently, the moments of the distribution of differences between photometric and true redshifts could be determined instead). The ultimate goal of calibration is to characterize these moments for every subsample used in analyses - i.e., to minimi

Novel Ag@TiO₂ nanocomposite synthesized by electrochemically active biofilm for nonenzymatic hydrogen peroxide sensor

Khan, M.M.,Ansari, S.A.,Lee, J.,Cho, M.H. Elsevier 2013 Materials science & engineering. C, Materials for Vol.33 No.8

A novel nonenzymatic sensor for H<SUB>2</SUB>O<SUB>2</SUB> was developed based on an Ag@TiO<SUB>2</SUB> nanocomposite synthesized using a simple and cost effective approach with an electrochemically active biofilm. The optical, structural, morphological and electrochemical properties of the as-prepared Ag@TiO<SUB>2</SUB> nanocomposite were examined by UV-vis spectroscopy, X-ray diffraction, transmission electron microscopy and cyclic voltammetry (CV). The Ag@TiO<SUB>2</SUB> nanocomposite was fabricated on a glassy carbon electrode (GCE) and their electrochemical performance was analyzed by CV, differential pulse voltammetry and electrochemical impedance spectroscopy. The Ag@TiO<SUB>2</SUB> nanocomposite modified GCE (Ag@TiO<SUB>2</SUB>/GCE) displayed excellent performance towards H<SUB>2</SUB>O<SUB>2</SUB> sensing at -0.73V in the linear response range from 0.83μM to 43.3μM, within a detection limit and sensitivity of 0.83μM and ~65.2328+/-0.01μAμM<SUP>-1</SUP>cm<SUP>-2</SUP>, respectively. In addition, Ag@TiO<SUB>2</SUB>/GCE exhibited good operational reproducibility and long term stability.

GP3 is a structural component of the PRRSV type II (US) virion

de Lima, M.,Ansari, I.H.,Das, P.B.,Ku, B.J.,Martinez-Lobo, F.J.,Pattnaik, A.K.,Osorio, F.A. Academic Press 2009 Virology Vol.390 No.1

Glycoprotein 3 (GP3) is a highly glycosylated PRRSV envelope protein which has been reported as being present in the virions of PRRSV type I, while missing in the type II PRRSV (US) virions. We herein present evidence that GP3 is indeed incorporated in the virus particles of a North American strain of PRRSV (FL12), at a density that is consistent with the minor structural role assigned to GP3 in members of the Arterivirus genus. Two 15aa peptides corresponding to two different immunodominant linear epitopes of GP3 derived from the North American strain of PRRSV (FL12) were used as antigen to generate a rabbit monospecific antiserum to this protein. The specificity of this anti-GP3 antiserum was confirmed by radioimmunoprecipitation (RIP) assay using BHK-21 cells transfected with GP3 expressing plasmid, MARC-145 cells infected with FL12 PRRSV, as well as by confocal microscopy on PRRSV-infected MARC-145 cells. To test if GP3 is a structural component of the virion, <SUP>35</SUP>S-labelled PRRSV virions were pelleted through a 30% sucrose cushion, followed by a second round of purification on a sucrose gradient (20-60%). Virions were detected in specific gradient fractions by radioactive counts and further confirmed by viral infectivity assay in MARC 145 cells. The GP3 was detected in gradient fractions containing purified virions by RIP using anti-GP3 antiserum. Predictably, the GP3 was less abundant in purified virions than other major structural envelope proteins such as GP5 and M. Further evidence of the presence of GP3 at the level of PRRSV FL12 envelope was obtained by immunogold staining of purified virions from the supernatant of infected cells with anti-GP3 antiserum. Taken together, these results indicate that GP3 is a minor structural component of the PRRSV type II (FL12 strain) virion, as had been previously described for PRRSV type I.

Enhanced thermoelectric performance and ammonia sensing properties of sulfonated polyaniline/graphene thin films

Ansari, M.O.,Khan, M.M.,Ansari, S.A.,Amal, I.,Lee, J.,Cho, M.H. North-Holland 2014 Materials letters Vol.114 No.-

Highly conducting nanocomposite film of polyaniline (Pani) with graphene (GN) was prepared by incorporating GN nanoplatelets in Pani matrix, followed by sulfonating it with fuming sulfuric acid. Sheet-like GN nanoplatelets were distributed uniformly in a Pani matrix, leading to high electrical conductivity due to π-π interaction between sulfonated Pani (s-Pani) and GN. Studies of the thermoelectrical behavior and ammonia-sensing behavior on GNσ-Pani showed high DC electrical conductivity retention under ageing conditions as well as excellent reproducible sensing response towards ammonia vapor in contrast to acid-protonated Pani.

Analysis of T-Slot Loaded Disk Patch Antenna for Dual Band Operation with Small Frequency Ratio

J. A. Ansari,Sapna Verma 보안공학연구지원센터 2015 International Journal of Future Generation Communi Vol.8 No.3

In this article, a dual band patch antenna is achieved by introducing T-slot in circular disk with small frequency ratio. It is theoretically investigated using equivalent circuit theory concept. The resonance frequency is found to be 1.84 and 2.02 GHz suitable for DCS-1800, PCS-1900 and IMT-2000 applications. The measured bandwidths at lower and upper resonances are found to be 6.59% and 6.89% respectively for proposed antenna specifications. The effect of slots dimension in the patch is studied. The frequency ratio is found to be 1.09. The maximum gain of the proposed antenna is found to be 6.52 dBi whereas efficiency is found to be 62.17% and 76.42% at lower and upper resonance frequencies respectively. The theoretical results are compared with simulated and measured results and they are in good agreement.

Highly visible light active Ag@ZnO nanocomposites synthesized by gel-combustion route

Ansari, S.A.,Khan, M.M.,Lee, J.,Cho, M.H. Korean Society of Industrial and Engineering Chemi 2014 Journal of industrial and engineering chemistry Vol.20 No.4

Highly visible light active 1% and 3% Ag@ZnO nanocomposites were synthesized via a gel combustion route using citric acid as a fuel. The formation of the nanocomposites with enhanced properties was confirmed using a range of characterization techniques, photocatalysis and photoelectrochemical studies. Compared to the pristine ZnO nanoparticles, the Ag@ZnO nanocomposites exhibited enhanced visible light photocatalytic activity for the degradation of methylene blue and photoelectrochemical response. A mechanism was proposed to account for the photocatalytic activities of the Ag@ZnO nanocomposite that showed the surface plasmon resonance (SPR) of Ag is an effective way of enhancing the visible light photocatalytic activities.

Preparation of nanofibers consisting of MnO/Mn3O4 by using the?electrospinning technique: the nanofibers have two band-gap energies

Barakat, N. A.,Woo, K. D.,Ansari, S. G.,Ko, J. A.,Kanjwal, M. A.,Kim, H. Y. Springer Science + Business Media 2009 APPLIED PHYSICS A MATERIALS SCIENCE AND PROCESSING Vol.95 No.3

Oxygen vacancy induced band gap narrowing of ZnO nanostructures by an electrochemically active biofilm

Ansari, S.,Khan, M.,Kalathil, S.,Nisar, A.,Lee, J.,Cho, M. Royal Society of Chemistry 2013 Nanoscale Vol.5 No.19

Mining phosphorus from anaerobically treated dairy manure by forward osmosis membrane

Biplob Kumar Pramanik,Faisal I. Hai,Ashley J. Ansari,Felicity A. Roddick 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.78 No.-

We investigated the effect of draw solution type on the forward osmosis (FO) performance for enrichingnutrients from anaerobically treated dairy manure (ATDM) followed by chemical precipitation forphosphorus recovery as struvite crystal. The FO membrane significantly rejected COD (>97%) andphosphate (>98%) whereas there was only 70%–73% and 73%–76% rejection of ammonia-nitrogen andtotal nitrogen, respectively. The draw solution type had little impact on the retention of theaforementioned wastewater constituents by the FO membrane. At 60% water recovery, a waterfluxdecline of 82%–96% was observed due to increasing contaminant concentration in the concentrated feedsolution. Waterflux decline was less for MgCl2 than EDTA-2Na and NaCl as draw solutes. On the contrary,the reverse soluteflux was higher for NaCl than MgCl2, which in turn was higher than EDTA-2Na. Preconcentrationof ATDM by FO facilitated struvite precipitation. MgCl2 as the draw solute provided ahigher purity of struvite than EDTA-2Na and NaCl. This is because when MgCl2 was used as the drawsolute, the reverse saltflux of magnesium to the concentrated ATDM provided favourable conditions forstruvite crystal formation. This study demonstrates the technical feasibility of phosphorus recovery fromATDM using the FO process.