Dr Sanjay Panwar | Maharaja Agrasen Institute of Technology (original) (raw)

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Papers by Dr Sanjay Panwar

Physica B: Condensed Matter

Bulletin of Materials Science, Jun 1, 2006

Bulletin of Materials Science, Jun 1, 2003

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment

Fyrir rétt taepum fimmtíu árum (1972) kom út bókin Endimörk vaxtarins, eða The Limits to Growth e... more Fyrir rétt taepum fimmtíu árum (1972) kom út bókin Endimörk vaxtarins, eða The Limits to Growth eins og hún kallaðist á frummálinu, en hún byggðist á rannsóknum vísindamanna við Taekniháskóla Massachusetts sem hugleiddu spurninguna hvernig mannkyni myndi farnast í heimi sem einkenndist af takmörkuðum gaeðum en saektist eftir takmarkalausum hagvexti. 1 Tímaspönnin sem rannsóknin tók til var eitt hundrað og þrjátíu ár eða um það bil frá árinu 1970-fram til ársins 2100. Fimm samverkandi þaettir voru skoðaðir sem allir voru taldir hafa mikil áhrif á framtíðina: fólksfjölgun, matvaelaframleiðsla, iðnvaeðing, þurrð náttúruauðlinda og mengun. Nýlega gaf einn höfunda Endimarka vaxtarins, Jørgen Randers, út bókina 2052 þar sem hann nýtir þekkingu sína og reynslu til að spá fyrir um framtíðina, nánar tiltekið tímabilið 2012 til 2052. 2 Bókin 2052 kom út á fjörutíu ára afmaeli Endimarka vaxtarins (2012) og má segja að í henni bergmáli baeði kunnugleg varnaðarorð frá 1972 en einnig mikilvaegir tónar framtíðarspár aettaðir úr skýrslu milliríkjanefndar SÞ frá árinu 2018. 3 Til að skilja betur inntak bókarinnar 2052 má nefna nokkur kjarnaatriði í Endimörkum vaxtarins sem hún kallast á við. Í inngangi Endimarka vaxtarins segjast höfundarnir vera uggandi um framtíð mannkynsins. Ástaeðan sé sú atburðarás sem hleypt hafi verið af stað af meira kappi en forsjá og vísuðu þar til ýmiskonar athafnasemi mannsins sem hefði neikvaeð áhrif á umhverfi og náttúru. Daemi um birtingarmyndir mannlegrar athafnasemi voru niðurníðsla umhverfisins, stofnanakreppa, taumlaus vöxtur borga, óstöðug atvinna, verðbólga, glundroði í efnahagsmálum og fleira. 4 Vöxtur eða réttara sagt veldisvöxtur er kjarnahugtak Endimarka vaxtarins. Segja má að flest þau fyrirbaeri sem rannsóknahópurinn beindi sjónum að, s.s. fólksfjölgunin, matvaelaframleiðslan, iðnvaeðingin, ágangur á náttúruauðlindir og mengun, hafi

A new model for investigating the value of thermal expansivity is presented. It has been found th... more A new model for investigating the value of thermal expansivity is presented. It has been found that the values obtained in the present study are consistent with the experimental data. The excellent agreement between results obtained and experimental data show the validity of the present work.

Bulletin of Materials Science, 2003

Investigations were carried out on aging of a HSLA-100 steel after varying amounts of cold deform... more Investigations were carried out on aging of a HSLA-100 steel after varying amounts of cold deformation. Mechanical properties (hardness, tensile properties and toughness) were measured and structural changes were studied using optical, TEM and SEM techniques. As a result of various treatments, the hardness and UTS could be significantly improved, but with drastic fall in ductility and impact strength, especially in peak aged conditions. The parameters affecting impact strength were examined and it was concluded that various microstructural features affected toughness through their influence on tensile properties. In this steel the impact strength could be improved by lowering the UTS and increasing the ductility (pct elongation). The improvement in hardness and UTS was attributed to formation of thick precipitate-dislocation tangles. The aging process caused a slow transformation of lath martensite into acicular ferrite due to occurrence of in situ recrystallization. The concentration of Cu in particles precipitating on aging was followed using EDAX technique.

Bulletin of Materials Science, 2006

Bulletin of Materials Science, 2007

International Journal of Innovative Technology and Exploring Engineering

Weathering steels developed under the name COR-TEN steels, established themselves as a promising ... more Weathering steels developed under the name COR-TEN steels, established themselves as a promising material to meet the demand for atmospheric corrosion resistance and eliminate the need for painting. COR-TEN steel is resistant to corrosive effect of weather such as rain, snow, ice, fog, etc. A coating of dark brown oxidation is developed over the metal surface, when it comes in contact with the environment thereby inhibiting the deeper penetration and negating the need for painting and reducing the rust-prevention cost over the years. Thus the steel is allowed to rust which forms a protective layer and slows down the rate of corrosion. The present study emphasizes the age hardening behavior of COR-TEN steel. The steel was subjected to solution treatment at 1000°C following accelerated cooling with water, oil and air. The oil quenched steel was then subjected to aging treatment at 400°C and 500°C for various times ranging from 5 min to 1500 min followed by water quenching. In order to...

Studies were carried out on the effect of austenitization and cooling of line-pipe HSLA steel. Ha... more Studies were carried out on the effect of austenitization and cooling of line-pipe HSLA steel. Hardness measurements were conducted after quenching/cooling the steel. As a result of change in quenching/cooling media hardness could be significantly altered. Consequently fast cooling rates, such as quenching in water and oil lead to high hardness levels as compared to the air cooling. Metallographic examinations revealed decomposition of austenite into martensite and ferrite together with formation of fine precipitate particles within the ferrite matrix and segregation of coarse/fine precipitate particles along the lath boundaries.

The studies of semiconductor core shell nanoparticles have advanced at a rapid pace because of th... more The studies of semiconductor core shell nanoparticles have advanced at a rapid pace because of the fact that their optical properties can be systematically tuned by varying their sizes. However, the optical properties of QDs have been found to be very sensitive to the physical and chemical properties of their surfaces. Core shells are compounds with specific characteristics and varied uses. Their high fluorescence and narrow spectrum shape makes them an excellent tagging alternative to conventional fluorescent dyes. During the past three decades, extensive research has been performed on the properties and uses of core shell nanoparticles. There are several viable methods to make quantum dots, but not all produce dots that can be used for environmental and biological testing. Properties (and therefore uses) are determined in part by the materials that quantum dots are made from as well as how the dots are made

Journal of Electronic Materials, 2021

ZnO-SiO2 nanocomposite thin films were synthesized using a facile and cost-effective chemical bat... more ZnO-SiO2 nanocomposite thin films were synthesized using a facile and cost-effective chemical bath deposition for different growth durations, under alkaline conditions on microscopic glass slides. Effect of deposition time on the morphological and optical properties were thoroughly investigated using x-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive x-ray analysis (EDX), transmittance and time-resolved photoluminescence studies, etc. XRD patterns confirmed the formation of ZnO and diffused ZnO-Silica phases of hetero-structures at a particular growth time starting from the amorphous silica phase. SEM micrographs revealed an appreciable change in morphology of the particles with increasing growth time. Uniform porous films with improved surface coverage resulted on the substrate after an incubation period of 2 h. The EDX spectra confirmed that the thin films composed of ZnO and silica co-exist without any other impurities. It was observed that transmittan...

Journal of Materials Science: Materials in Electronics

Russian Journal of Physical Chemistry A

Journal of the Korean Physical Society

Journal of Materials Science: Materials in Electronics, 2016

International Journal of Scientific and Engineering Research

Journal of Materials Science: Materials in Electronics, 2013

In this work, synthesis and characterization of core-shell zinc sulphide (ZnS)/zinc oxide (ZnO) n... more In this work, synthesis and characterization of core-shell zinc sulphide (ZnS)/zinc oxide (ZnO) nanocomposites has been reported to see the effect of ZnO concentration in core-shell combination. The nascent as well as core-shell nanostructures were prepared by a chemical precipitation method starting with the synthesis of nascent ZnS nanoparticles. The change in morphological and optical properties of core-shell nanoparticles was studied by changing the concentration of ZnO for a fixed amount of ZnS. The nascent ZnS nanoparticles were of 4-6 nm in diameter as seen from TEM, each containing primary crystallites of size 1.8 nm which was estimated from the X-ray diffraction patterns. However, the particle size increases appreciably with the increase in ZnO concentration leading to the well known ZnO wurtzite phase coated with FCC phase of ZnS. Band gap studies were done by UV-visible spectroscopy and it shows that band gap tunability can be achieved appreciably in case of ZnS/ ZnO core-shell nanostructures by varying the concentration of ZnO. Fourier transform infrared analysis also proves the formation of core-shell nanostructures. Photoluminescence studies show that emission wavelength blue shifts with the increase in ZnO concentration. These coreshell ZnS/ZnO nanocomposites will be a very suitable material for any type of optoelectronic application as we can control various parameters in this case in comparison to the nascent nanostructures.