A highly efficient visible-light responsive sprayed WO₃/FTO photoanode for photoelectrocatalytic degradation of brilliant blue

Hunge, Y.M.,Yadav, A.A.,Mahadik, M.A.,Mathe, V.L.,Bhosale, C.H. Elsevier 2018 Journal of the Taiwan Institute of Chemical Engine Vol.85 No.-

<P><B>Abstract</B></P> <P>In present article, WO<SUB>3</SUB> thin films have been successfully synthesized by chemical spray pyrolysis approach. The effect of spraying quantity of solution onto the photoelectrochemical (PEC), structural, morphological, and optical properties has been studied. Film prepared at 40 ml solution quantity shows the excellent photoelectrochemical performance (<I>I</I> <SUB>sc</SUB> <SUB> </SUB>= 0.69 mA/cm<SUP>2</SUP> and <I>V</I> <SUB>oc</SUB> = 0.64 V) in 0.05 M concentrated H<SUB>2</SUB>SO<SUB>4</SUB> electrolyte. X-ray diffraction studies reveal that the synthesized WO<SUB>3</SUB> thin films are polycrystalline with monoclinic crystal structure. The chief vibrational modes of the WO<SUB>3</SUB> sample, located at 712.64 and 804.28 cm<SUP>−1</SUP> corresponding to the stretching and the bending of OWO bond respectively and are consistent with a monoclinic structure. The estimated band gap energy of WO<SUB>3</SUB> thin films varies from 2.37 to 2.45 eV with respect to quantities of spraying solution and it exhibits absorption in visible region. Film shows a maximum specific surface area of 31.63 m<SUP>2</SUP>/g. Photoelectrocatalytic degradation of brilliant blue dye in aqueous solutions is studied. The end result shows that the degradation percentage of brilliant blue using WO<SUB>3</SUB> photoelectrode has reached 92% under visible light illumination after 240 min. The enhancement in photoelectrocatalytic activity of optimized 40 ml WO<SUB>3</SUB> sample is mainly due to the suppressed the recombination rate of photogenerated electron–hole pairs. This study provides an effective WO<SUB>3</SUB> photoelectrode for removing of organic pollutants present in the water.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Monoclinic WO<SUB>3</SUB> homogeneous thin films prepared by the simple, cost-effective, eco-friendly spray pyrolysis approach. </LI> <LI> Photoelectrode with 710 nm thickness display superior photocatalytic degradation of brilliant blue dye. </LI> <LI> Degradation rate constant was 0.2238 cm<SUP>3</SUP>/s for BB under visible-light illumination. </LI> <LI> Decreased COD values from 76 to 16 mg/l confirm the mineralization of the BB dye molecule. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Room temperature liquefied petroleum gas sensing using Cu₂SnS₃/CdS heterojunction

Lokhande, A.C.,Yadav, A.A.,Lee, JuYeon,He, Mingrui,Patil, S.J.,Lokhande, V.C.,Lokhande, C.D.,Kim, Jin Hyeok Elsevier 2017 JOURNAL OF ALLOYS AND COMPOUNDS Vol.709 No.-

<P><B>Abstract</B></P> <P>In the present work, for the first time, we report the fabrication of Cu<SUB>2</SUB>SnS<SUB>3</SUB> (CTS)/CdS heterojunction for room temperature (27 °C) liquefied petroleum gas (LPG) sensing. The heterojunction is formed between sputter deposited CTS thin films and chemically bath deposited CdS thin films. The structural, morphological and optical properties of the thin films are evaluated using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and UV–visible spectroscopy techniques, respectively. The fabricated heterojunction quality is evaluated from the forward biased current-voltage (I-V) study and the influence of annealing treatment of p-CTS thin film on LPG sensing properties of the heterojunction has been investigated. The CTS/CdS heterojunction exhibits maximum LPG response of 56% at room temperature under exposure of 780 ppm LPG concentration with 31s and 56s response and recovery time, respectively. The device retained 95% gas sensing stability after time period of 60 days suggesting that the fabricated CTS/CdS heterojunction is reliable and promising for LPG sensing. The factors affecting LPG sensing performance and plausible gas sensing mechanism are discussed in this study.</P> <P><B>Highlights</B></P> <P> <UL> <LI> CTS/CdS heterojunction based LPG sensor. </LI> <LI> 56% LPG sensing response upon exposure of 780 ppm LPG concentration. </LI> <LI> 95% gas sensing stability of the junction after time period of 60 days. </LI> <LI> LPG gas sensing mechanism. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Nanocrystalline hydroxyapatite doped with aluminium: A potential carrier for biomedical applications

Kolekar, T.V.,Thorat, N.D.,Yadav, H.M.,Magalad, V.T.,Shinde, M.A.,Bandgar, S.S.,Kim, J.H.,Agawane, G.L. Ceramurgica ; Elsevier Science Ltd 2016 CERAMICS INTERNATIONAL Vol.42 No.4

Biocompatible materials based on hydroxyapatite are potentially attractive for a wide range of medical applications. The effect of aluminium substitution on the biocompatibility of hydroxyapatite (HA) under the physiochemical conditions has been investigated. Various samples of aluminium doped hydroxyapatite (Al-HA) with different concentration (0, 0.5, 1.0, 1.5, 2.0, 2.5mol%) were successfully synthesised by solution combustion method and characterized by X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM), and Scanning Electron Microscopy (SEM), and thermal analysis technique. XRD and TEM results reveal uniform and crystalline nature of Al-HA nanoparticles. The biocompatibility of the Al-HA nanoparticles was studied using L929 cell lines by MTT assays up to 24h. These Al-HA nanoparticles are biocompatible on cell lines L929 and do not have toxic effects for further possible in vivo applications. The results of these studies confirmed the biocompatibility of Al-HA and demonstrated the suitability for biomedical applications. The present work reveals the importance of structural, morphological, biocompatible properties of Al-HA nanoparticles and predicts the suitability for biomedical applications.

Enhanced Hemolytic Biocompatibility of Hydroxyapatite by Chromium (Cr³⁺) Doping in Hydroxyapatite Nanoparticles Synthesized by Solution Combustion Method

Bandgar, Sneha S.,Yadav, Hemraj M.,Shirguppikar, Shailesh S.,Shinde, Mahesh A,Shejawal, Rajendra V.,Kolekar, Tanaji V.,Bamane, Sambhaji R. The Korean Ceramic Society 2017 한국세라믹학회지 Vol.54 No.2

For the better success of biomedical implant surgery, we used a modified solution combustion method to synthesize Hydroxyapatite (HA) and Chromium ($Cr^{3+}$) modified Cr-HA with different concentrations of 0.5, 1.0, 1.5, 2.0 and 2.5. The Cr-HA nanopowder was characterized by TGA, XRD, SEM-EDS and TEM. The HA and Cr-HA powders were subjected to in vitro biological studies to determine their biocompatibility and hemocompatibility. The cytotoxicity of HA and Cr-HA were evaluated on Hela (Cervical cancer) cells and L929 (mouse fibroblast) cells by using MTT assay. Hemocompatibility studies demonstrated a noticeable haemolytic ratio below 5%, which confirms that these materials are compatible in nature with human blood. The results of the present work confirm that the synthesised HA and Cr-HA are biocompatible and can be extensively used in the biomedical field to improve overall material biological properties.

Ageing and vapor chopping effect on the properties of MgO thin films

Tamboli, S.H.,Jatratkar, A.,Yadav, J.B.,Puri, V.,Puri, R.K.,Cho, H.H. Elsevier Sequoia 2014 JOURNAL OF ALLOYS AND COMPOUNDS Vol.588 No.-

Nanoscale magnesium oxide thin films have been prepared on glass substrates by thermal oxidation (in air) of vacuum evaporated magnesium films. The ageing (air exposure) effect for 1, 10, 20 and 30days on the various properties of MgO thin films was studied. The ageing effect on the optoelectronic devices i.e. optical waveguide and plasma display panel's performance was examined by measuring their optical transmission loss and secondary electron emission yield, respectively. Vapor chopping technique was employed for thin film quality improvement followed by ageing inhibition. The firing voltage for fresh vapor chopped (VC) MgO thin films was in 125-150V range, which shifted to 140-178V after 30days, whereas in the non-chopped (NC) films it increased up to 165-210V from 140-160V. After 30days ageing, NC thin film surface morphology changed from polished to dull due to wrapped moisture like layer, whereas VC thin film morphology was unpretentious. The XPS analysis also confirmed the VC MgO thin films superior sustainability against the ageing than NC films.

Measurement of outgassing rates of Kevlar and S-Glass materials used in torque tubes of High Tc Superconducting (HTS) Motors

S. Thadela,B V A S Muralidhar,B Kalyani,U K Choudhury,S N Yadav,V. V. Rao 한국초전도.저온공학회 2018 한국초전도저온공학회논문지 Vol.20 No.4

Torque tubes in High Temperature Superconducting (HTS) motor transfer torque from superconducting field winding rotor to the room temperature shaft. It should have minimum heat conduction property for minimizing the load on cryo-refrigerator. Generally, these torque tubes are made with stainless steel material because of high strength, very low outgassing and low thermal contraction properties at cryogenic temperatures and vacuum conditions. With recent developments in composite materials, these torque tubes could be made of composites such as Kevlar and S-Glass, which have the required properties like high strength and low thermal conductivity at cryogenic temperatures, but with a reduced weight. Development and testing of torque tubes made of these composites for HTS motor are taken up at Bharat Heavy Electricals Limited (BHEL), Hyderabad in collaboration with Central Institute of Plastics and Engineering Technology (CIPET), Chennai and Indian Institute of Technology (IIT), Kharagpur. As these materials are subjected to vacuum, it is important to measure their outgassing rates under vacuum conditions before manufacturing prototype torque tubes. The present study focusses on the outgassing characteristics of Kevlar and S-Glass, using an Outgassing Measurement System (OMS), developed at IIT Kharagpur. The OMS facility works under vacuum environment, in which the test samples are exposed to vacuum conditions over a sufficient period of time. The outgassing measurements for the composite samples were obtained using pressure-rise technique. These studies are useful to quantify the outgassing rate of composite materials under vacuum conditions and to suggest them for manufacturing composite torque tubes used in HTS motors.

Degradation of organic dyes using spray deposited nanocrystalline stratified WO₃/TiO₂ photoelectrodes under sunlight illumination

Hunge, Y.M.,Yadav, A.A.,Mahadik, M.A.,Bulakhe, R.N.,Shim, J.J.,Mathe, V.L.,Bhosale, C.H. Elsevier 2018 Optical materials Vol.76 No.-

<P><B>Abstract</B></P> <P>The need to utilize TiO<SUB>2</SUB> based metal oxide hetero nanostructures for the degradation of environmental pollutants like Rhodamine B and reactive red 152 from the wastewater using stratified WO<SUB>3</SUB>/TiO<SUB>2</SUB> catalyst under sunlight illumination. WO<SUB>3</SUB>, TiO<SUB>2</SUB> and stratified WO<SUB>3</SUB>/TiO<SUB>2</SUB> catalysts were prepared by a spray pyrolysis method. It was found that the stratified WO<SUB>3</SUB>/TiO<SUB>2</SUB> heterostructure has high crystallinity, no mixed phase formation occurs, strong optical absorption in the visible region of the solar spectrum, and large surface area. The photocatalytic activity was tested for degradation of Rhodamine B (Rh B) and reactive red 152 in an aqueous medium. TiO<SUB>2</SUB> layer in stratified WO<SUB>3</SUB>/TiO<SUB>2</SUB> catalyst helps to extend its absorption spectrum in the solar light region. Rh B and Reactive red 152is eliminated up to 98 and 94% within the 30 and 40 min respectively at optimum experimental condition by stratified WO<SUB>3</SUB>/TiO<SUB>2</SUB>. Moreover, stratified WO<SUB>3</SUB>/TiO<SUB>2</SUB> photoelectrode has good stability and reusability than individual TiO<SUB>2</SUB> and WO<SUB>3</SUB> thin film in the degradation of Rh B and reactive red 152. The photoelectrocatalytic experimental results indicate that stratified WO<SUB>3</SUB>/TiO<SUB>2</SUB> photoelectrode is a promising material for dye removal.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Enhanced photoelectrocatalytic activity of sprayed deposited stratified WO<SUB>3</SUB>/TiO<SUB>2</SUB> thin films. </LI> <LI> Photoelectrocatalytic degradation of rhodamine B and reactive red 152 dye. </LI> <LI> Reaction kinetics and degradation of pollutants by COD measurement. </LI> </UL> </P>

X-RAY ASTRONOMY EXPERIMENT ON THE INDIAN SATELLITE IRS-P3

AGRAWAL P. C.,PAUL B.,RAO A. R.,SHAH M. R.,MCKERJEE K.,VARIA M. N.,YADAV J. S.,DEDHIA D. K.,MALKAR J. P.,SHAH P.,DAMLE S. V.,MARAR T. M. K.,SEETHA S. The Korean Astronomical Society 1996 Journal of The Korean Astronomical Society Vol.29 No.suppl1

An x-ray astronomy experiment consisting of three collimated proportional counters and an X-ray Sky Monitor (XSM) was flown aboard the Indian Satellite IRS-P3 launched on March 21, 1996 from SHAR range in India. The Satellite is in a circular orbit of 830 km altitude with an orbital inclination of $98^{\circ}$ and has three axis stabilized pointing capability. Each pointed-mode Proportional Counter (PPC) is a multilayer, multianode unit filled with P-10 gas ($90\%$ Ar + $10\%\;CH_4$) at 800 torr and having an aluminized mylar window of 25 micron thickness. The three PPCs are identical and have a field of view of $2^{\circ}{\times}2^{\circ}$ defined by silver coated aluminium honeycomb collimators. The total effective area of the three PPCs is about 1200 $cm^2$. The PPCs are sensitive in 2-20 keV band. The XSM consists of a pin-hole of 1 $cm^2$ area placed 16 cm above the anode plane of a 32 cm$\times$32 cm position sensitive proportional counter sensitive in 3-8 keV interval. The position of the x-ray events is determined by charge division technique using nichrome wires as anodes. The principal objective of this experiment is to carry out timing studies of x-ray pulsars, x-ray binaries and other rapidly varying x-ray sources. The XSM will be used to detect transient x-ray sources and monitor intensity of bright x-ray binaries. Observations of black-hole binary Cyg X-1 and few other binary sources were carried out in early May and July-August 1996 period. Details of the x-ray detector characteristics are presented and preliminary results from the observations are discussed.

Enhanced visible light photocatalytic activity of Cr³⁺-doped anatase TiO₂ nanoparticles synthesized by sol-gel method

Yadav, H. M.,Kolekar, T. V.,Barge, A. S.,Thorat, N. D.,Delekar, S. D.,Kim, B. M.,Kim, B. J.,Kim, J. S. Chapman and Hall 2016 Journal of materials science Materials in electron Vol. No.

<P>The photocatalytic degradation of methylene blue (MB) has been investigated under visible light irradiation with an incandescent light bulb using chromium doped TiO2 nanoparticles. Cr-TiO2 photocatalysts were successfully synthesized by sol-gel method at room temperature and characterized by X-ray diffraction (XRD), UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS), Raman spectroscopy, Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy. The band gap energy of the nanoparticles were estimated using UV-Vis DRS technique. With increasing Cr3+ cations content into TiO2 host lattice, the optical absorption band tuned in the visible region. XRD and TEM results reveal uniform and crystalline anatase TiO2 nanoparticles. The photodegradation of MB indicated that the photocatalytic activity of pure TiO2 nanoparticles increased with increasing Cr3+ cations concentration.</P>

Subfertility in Males: An Important Cause of Bull Disposal in Bovines

Mukhopadhyay, C.S.,Gupta, A.K.,Yadav, B.R.,Khate, K.,Raina, V.S.,Mohanty, T.K.,Dubey, P.P. Asian Australasian Association of Animal Productio 2010 Animal Bioscience Vol.23 No.4

The study had two objectives, namely, to estimate the andrological disorders leading to disposal of Karan Fries (KF), Sahiwal cattle and Murrah buffalo bulls and to study the effect of various factors (species/breeds, season of birth and period of birth) on male reproductive parameters. Records on occurrence of subfertility problems and disposal pattern of bulls maintained at the National Dairy Research Institute herd were collected for 15 years (1991 to 2005). Percentage of bulls producing freezable semen was less in the crossbred cattle (58.46%) as compared to Sahiwal (81.69%) and Murrah bulls (81.05%). Various subfertility traits like poor libido and unacceptable seminal profile were found to be the significant reasons (p<0.01) for culling of the breeding bulls. Inadequate sex drive was the main contributing factor for bull disposal in Sahiwal (22.55%) and Murrah bulls (15.12%) whereas poor semen quality and freezability were most frequently observed in KF bulls (24.29 and 7.29 percent, respectively). Least squares analyses of different male reproductive parameters showed that species/breeds had significant effect (p<0.05) on all traits except for frozen semen production periods (FSPP). Periods of birth were significantly different (p<0.05) for all traits except for semen volume. Age at first semen collection (AFSC), age at first semen freezing (AFSF) and age at disposal (AD) were highest in Murrah, while frozen semen production period (FSPP) and semen production period (SPP) were highest in KF and lowest in Sahiwal. The age at first semen donation and breeding period could be reduced by introducing the bulls to training at an early age. These results revealed a declining trend in AFSC, AFSF, FSPP, SPP and AD, thereby indicating an improvement in reproductive performance over the years. The age at first semen donation in bovines can be reduced by introducing the young male calves to training at an early age, which could increase the dosage of semen obtained from each male.