harish verma - Academia.edu (original) (raw)

Papers by harish verma

Micro & Nano Letters, 2015

The Strathprints institutional repository (https://strathprints.strath.ac.uk) is a digital archiv... more The Strathprints institutional repository (https://strathprints.strath.ac.uk) is a digital archive of University of Strathclyde research outputs. It has been developed to disseminate open access research outputs, expose data about those outputs, and enable the management and persistent access to Strathclyde's intellectual output.

Journal of Infectious Diseases, 2016

Background. Nigeria was one of 3 polio-endemic countries before it was de-listed in September 201... more Background. Nigeria was one of 3 polio-endemic countries before it was de-listed in September 2015 by the World Health Organization, following interruption of transmission of the poliovirus. During 2011-2014, Nigeria conducted serial polio seroprevalence surveys (SPS) in Kano Metropolitan Area, comprising 8 local government areas (LGAs) in Kano that is considered very high risk (VHR) for polio, to monitor performance of the polio eradication program and guide the program in the adoption of innovative strategies. Methods. Study subjects who resided in any of the 8 local government areas of Kano Metropolitan Area and satisfied age criteria were recruited from patients at Murtala Mohammed Specialist Hospital (Kano) for 3 seroprevalence surveys. The same methods were used to conduct each survey. Results. The 2011 study showed seroprevalence values of 81%, 75%, and 73% for poliovirus types 1, 2, and 3, respectively, among infants aged 6-9 months age. Among children aged 36-47 months, seroprevalence values were greater (91%, 87%, and 85% for poliovirus types 1, 2, and 3, respectively). In 2013, the results showed that the seroprevalence was unexpectedly low among infants aged 6-9 months, remained high among children aged 36-47 months, and increased minimally among children aged 5-9 years and those aged 10-14 years. The baseline seroprevalence among infants aged 6-9 months in 2014 was better than that in 2013. Conclusions. The results from the polio seroprevalence surveys conducted in Kano Metropolitan Area in 2011, 2013, and 2014 served to assess the trends in immunity and program performance, as well as to guide the program, leading to various interventions being implemented with good effect, as evidenced by the reduction of poliovirus circulation in Kano.

Journal of Alloys and Compounds, 2015

Abstract Here, we report on the enhancement in the magnetic properties of polycrystalline Bi1−xBa... more Abstract Here, we report on the enhancement in the magnetic properties of polycrystalline Bi1−xBaxFeO3 (x = 0.0, 0.05, 0.1 and 0.2) ceramic samples as a consequence of mechanical activated solid-state-reaction in comparison to standard solid-state-reaction processed samples. Our results suggest that mechanical activation has pronounced effect on the temperature of phase evolution as well as magnetic characteristics of Ba doped BiFeO3. The temperature, at which perovskite phase crystallizes is lower for mechanical activation assisted samples than for standard solid-state-reaction processed samples, attributed to pre-alloying during mechanical activation process. All the samples crystallize in a distorted perovskite structure with space group R3c and no structural change is found up to highest Ba doping. Mechanical activation also leads to significantly altered magnetic properties, particularly in higher Ba-doping samples which show about 50% increase in the magnetization and more than three fold increase in the coercive field. Local magnetic behavior investigated by 57Fe Mossbauer spectroscopy rules out any valence fluctuations of Fe and the hyperfine field corroborates the magnetization data.

Materials Science Forum, 2004

Abstract. Using the 511-511 keV gamma ray coincidence-based Doppler broadening measurements, it i... more Abstract. Using the 511-511 keV gamma ray coincidence-based Doppler broadening measurements, it is found that the positron trapping sites in nanocrystalline ZnFe2O4 are surrounded by Zn 2+ ions. This was inferred from the observation of a characteristic peak around 515.8 keV in the normalised tail of the Doppler broadened gamma ray spectrum of ZnFe2O4 and which exactly coincided with that of pure Zn. The intensity of the peak enhanced when the grain size is reduced from 7nm to 6 nm, depicting an increased ...

Engineering in Agriculture, Environment and Food, 2015

Abstract This paper discusses the implementation of greenhouse climate control simulator based up... more Abstract This paper discusses the implementation of greenhouse climate control simulator based upon dynamic model with intuitive user interface that provides various options to simulate greenhouse climate under open and closed loop control conditions. The simplified greenhouse climate model based upon mass and energy balance principle, encapsulates the realistic situations in a greenhouse to simulate and analyze the effect of different control strategies (shading, ventilation, cooling or heating) on inside climate for various greenhouse design configurations and under different weather conditions. The model is integrated with the proposed greenhouse-crop vapor pressure deficit (GH-crop VPD) based multi-input multi-output fuzzy climate controller that operates in feedforward mode and regulates greenhouse climate conducive for healthy plant growth and yield. Under closed loop operation, the controller automatically readjusts the operating status and rate of different climate control equipments (shade screen, roof vents, exhaust fan, cooling system and heating system) and simulates automatic control of GH-crop VPD within set limits irrespective of the variations in outside weather conditions. Designed as an educational tool, the simulator was used under open loop to demonstrate how for a selected greenhouse design and weather conditions, different climate control strategies affect greenhouse climate conditions. Multiple simulations run under different scenarios were simultaneously displayed for comparison study and analysis. Further, the closed loop simulations were performed that indicated high performance of the controller in regulating GH-crop VPD under different hot weather conditions and depicted what systems (rate and operating status of different climate control equipments) would be needed to meet desired conditions.

Journal of The Institution of Engineers (India): Series B, 2015

The main objective of an image enhancement is to improve eminence by maximizing the information c... more The main objective of an image enhancement is to improve eminence by maximizing the information content in the test image. Conventional contrast enhancement techniques either often fails to produce reasonable results for a broad variety of low-contrast and high contrast images, or cannot be automatically applied to different images, because they are parameters dependent. Hence this paper introduces a novel hybrid image enhancement approach by taking both the local and global information of an image. In the present work, sigmoid function is being modified on the basis of contrast of the images. The gray image enhancement problem is treated as nonlinear optimization problem with several constraints and solved by particle swarm optimization. The entropy and edge information is included in the objective function as quality measure of an image. The effectiveness of modified sigmoid function based enhancement over conventional methods namely linear contrast stretching, histogram equalization, and adaptive histogram equalization are better revealed by the enhanced images and further validated by statistical analysis of these images.

~u r h o n .rc ro prrpuc thctr r m n u w~~p u carcfully acconllng to the followng inmumions Failu... more ~u r h o n .rc ro prrpuc thctr r m n u w~~p u carcfully acconllng to the followng inmumions Failure to do so will result In the rmnuunpt., k i n g-d to the author fm rcv~rim All manuscnpn arc cons~dcrcd on thc undcrstandlng that d r q v d 1he3 will not be offcrcd for publ~cation elsewhere I. GESERAL Pfor publrcaoon arc acccpted from ROM staff mcmbcn. Rcxarch Associates. or from researchers repomng on work done ulth ROM collcct~ons In cxcepuonnl caws.monognpbc works on the flora andor fauna of Onuno will bc conr~derd for publicauon b) authors not affiliated wlth the ROM. Authors arc expected to w n u clcul? ud conc~uly. and to omit 111 mtenal not csrcntlal for an u n d e n t d~n g of thc man them of the papr. 2 FORMAT Manuscnpn arc lo bc wpcd double-spaced (mcludng caprlons. symnomtes. literatuft cltcd. and lables) on I I" x 8%" paper w~th a I H" margtn on all szdcs Three xcrox copies arc to be submincd to the Chaman of the Editorial Boud. and the onglnal retained b) the nuthor(s). A separate sheet IS to be subnuncd glvlng author(s) namcs. aflil!at~on. t~tlc of publlcaoon. wncr ~n whch II IS to appear, numbcr of typd pages. number of obles. and number of figures Manurcnpts shwld normall) bc organized In the following order. Table of Contents. Ahsuact. Introduct~on. Matenals and Methods. Rcruln. Dacuss~on. Concluaons. Summary (d paper 1s long). Acknouledgements, L!terarure Cgted. and Appndlccs Authors arc encouragcd to rnclude forclgn language lranslat~ons of the Summar) *,here appropnale Hcadlngr of sccllons are to bc leh-justfied lo the text m q i n. The lint line of the first paragraph In cach neu sectton should not be tndentcd. Text-figurer arc refemd to as "Ftg I". Llararure ciled In thc text is In the form "Jones (1972)" or "(Jones. 19721" or "(Smith. 1960:71-79. fig 17)". 3. STANDARD SOURCES The primaq source for dec~stanr on format and style IS A Guide lor Contributors and Editors d ROM Life S c i c m Publications. available from the Cha~rman of the Fd~tonal Board Orherwtsc. consult CBE (AIBSl S~l c Manual (3rd Ed~tnonl Other standard sources are as follows: for English spclling (Conaw Oxford D~ct!onaql. for Canadan place namcs and cwrdrnates (Gazetteer of Canada). and for spell~ng of geograph~c namcs (T~mcr [Landon] Atlas) 4 ABSTRACT All papers are preceded b! a shon and factual abstract, about 3 pcr cent as long as t k e r r. but not longcr than 400 words The absusct IS to bc followed b) four to slr keywords enclosed In braclets 5 TAXONOMY Thc namc of a m o n is glven In full m headings, where 11 appears for the first ume. or when the name m. beg~ni a paragraph U x authority and date ~f appropnate. with first ment~on of cach oxon and not thereafter Thl~nomlc papen follow the layout In Llfc Sc~enccs Contribuuon 99. panlcularl) the synonomtes 6 LITERATURE CITED References In the text ate author and date and arc enclosed In parenthercs tSrmth. 1978). Complete refcrcnccs arc listed In alphakt~cal ordcr by authw at thc end of the papcr When thcre arc two or more cltstlons for an author. the works arc ltsted chronologtcally. Names of journals are not abbrevlatul. Consult Life Sclcnces Contnbut~ons bcg~nning w!lh 117 for comct b~bliograph~c f o m. 7 TABLES All tables arc numkred consccut~vcl) In arabic numerals m numcncal order of their fin1 mcnuon In the text Marl t k appropriate text location of each table wrth a marginal notallon. Each table IS ~yped on a separate shcct. Avoid fmlnotcs etc.. to tables by bulld!np them into the tale. 8. FIGL'RES All figures are numkred consecutivel) In arablc numerals. Component photographs or drawlngs are labcllcd q u c n t~a l l y In uppcr case lettcrs Mark the appropnate text location of each figure ~8 t h a marg~nal noot~on. The mended reduct~on for figures IS tdeall) one and a half to two tlmes All labelling on figurer IS In blur pencil and no1 l d e d w Ietraset Halftones must be photograph~c pnnts of high contrast on gloss) paper Authors are to subnut 10" 8" copies wlth the MS and retain ong~nals untll the) are requested Fagure captlonr are lo appear grouped toeelher on a separate pagc at the end of the MS *this pdf prepared from x-copy of the reduced size, thus for true size ammonite images should be enlarged LIFE SCIENCES CONTRIBUTIONS ROYAL ONTARIO MUSEL'M NUMBER 135

$Research paper thumbnail of Fe-bearing phases in a ureilite fragment from the asteroid 2008 TC 3 (= Almahata Sitta meteorites): A combined Mössbauer spectroscopy and X-ray diffraction study$

Meteoritics & Planetary Science, 2014

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10% Co-doped BiFeO3 nanoparticles have been prepared by a low temperature sol-gel method. XRD res... more 10% Co-doped BiFeO3 nanoparticles have been prepared by a low temperature sol-gel method. XRD result shows that particles are single phase in nature and crystallizes in distorted perovskite structure (space group R3c) with average particle size of 60 nm. Room temperature ferromagnetism along with saturation magnetization of about 2.24 emu/g and high coercive field of 1260 Oe has been found

AIP Advances, 2013

Structural and magnetic properties of Cr doped BiFeO 3 multiferroic nanoparticles

Journal of Infectious Diseases, 2014

Background. In 2009, enhanced poliovirus surveillance was established in polio-endemic areas of U... more Background. In 2009, enhanced poliovirus surveillance was established in polio-endemic areas of Uttar Pradesh and Bihar, India, to assess poliovirus infection in older individuals. Methods. In Uttar Pradesh, stool specimens from asymptomatic household and neighborhood contacts of patients with laboratory-confirmed polio were tested for polioviruses. In Bihar, in community-based surveillance, children and adults from 250 randomly selected households in the Kosi River area provided stool and pharyngeal swab samples that were tested for polioviruses. A descriptive analysis of surveillance data was performed. Results. In Uttar Pradesh, 89 of 1842 healthy contacts of case patients with polio (4.8%) were shedding wild poliovirus (WPV); 54 of 85 (63.5%) were ≥5 years of age. Shedding was significantly higher in index households than in neighborhood households (P < .05). In Bihar, 11 of 451 healthy persons (2.4%) were shedding WPV in their stool; 6 of 11 (54.5%) were ≥5 years of age. Mean viral titer was similar in older and younger children. Conclusions. A high proportion of persons ≥5 years of age were asymptomatically shedding polioviruses. These findings provide indirect evidence that older individuals could have contributed to community transmission of WPV in India. Polio vaccination campaigns generally target children <5 years of age. Expanding this target age group in polio-endemic areas could accelerate polio eradication.

Scanning, 2014

ABSTRACT Locating and profiling porosity or cavities in materials science has been of great inter... more ABSTRACT Locating and profiling porosity or cavities in materials science has been of great interest and importance. However, it has been a great challenge to detect and analyze these hidden cracks because of lack of efficient measurement technique. Artificial voids are created and covered by self-supporting thin films in order to replicate a hidden crack situation. Subsequently, these hidden voids are located in the scanning electron microscope images and the backscattered electrons, which emerge from a deeper part of a material and depend on the material property (such as atomic number, atomic density, etc.), are shown to play the key role in locating these hidden voids. Detection has been done by collecting the backscattered electrons as well as the secondary electrons (produced by the backscattered electrons). The efficacy of the detection technique is presented in terms of variation in the grayscale intensity values of the scanning electron microscope images. The role of the primary beam energy and the beam dwell time in the detection efficiency is discussed. The successful demonstration of the imaging technique in profiling hidden voids shows a promising and efficient analytical technique in detecting and analyzing invisible cracks in materials. SCANNING 9999:1–7, 2014. © Wiley Periodicals, Inc.

Radiation Physics and Chemistry, 1998

... Titre du document / Document title. Mev ion beam mixing of Au in Fe 78 B 13 Si 9 amorphous me... more ... Titre du document / Document title. Mev ion beam mixing of Au in Fe 78 B 13 Si 9 amorphous metallic alloy. Auteur(s) / Author(s). DHAR S. (1) ; SOM T. (1) ; VERMA HC (1) ; KULKARNIVN (1) ; Affiliation(s) du ou des auteurs / Author(s) Affiliation(s). ...

Powder Technology, 2003

Nanosized zinc ferrite of controlled crystallite size has been prepared by calcining an amorphous... more Nanosized zinc ferrite of controlled crystallite size has been prepared by calcining an amorphous zinc-iron-citrate precursor at different temperatures up to 650 jC. The variation of crystallite size with calcination temperature has been investigated using X-ray diffraction (XRD), thermogravimetry-differential thermal analysis (TG-DTA), and transmission electron microscopy (TEM), and a recipe for the preparation of nano zinc ferrite of desired size has been developed. Zinc ferrite has been found to crystallize at temperatures as low as 200 jC and calcination time as little as 1 h. The crystallite size varied from 7 to 23 nm as the calcination temperature was increased from 200 to 600 jC. It has been observed that the crystallization of zinc ferrite from the amorphous powder is complete at 350 jC, forming 7-nm crystallites. Calcination at higher temperatures leads to a linear growth of the crystallites from 7 nm at 350 jC to 23 nm at 600 jC.

Physica B: Condensed Matter, 2014

ABSTRACT Nanosized hematite with 1.53% Mg well dispersed in the crystal could be prepared using a... more ABSTRACT Nanosized hematite with 1.53% Mg well dispersed in the crystal could be prepared using a wet chemical method. The chemical reaction followed by aging at 60 degrees C for 12?h produced Mg-doped hematite of mean crystallite size (MCD) 78 nm as shown by X-ray diffraction. Transmission electron microscopy measurement showed that particles are nearly spherical in shape. However, FTIR and differential thermal analysis results indicated presence of ferric hydroxide phase which was also confirmed from Mossbauer spectroscopy. The sample annealed at 400 degrees C did not show any extra phase other than alpha-Fe2O3. Mg-doped alpha-Fe2O3 showed a weak ferromagnetism with a hysteresis loop superimposed on antiferromagnetic M-H curve. The saturation magnetization and coercivity decreased when the sample was annealed at 400 degrees C. The presence of ferrihydrite in alpha-Fe2O3 matrix seems to provide pinning centers for domain walls, increasing the coercivity showing that this composite can also be an interesting magnetic material. Mossbauer spectrum of (a) as-prepared and (b) annealed sample of Mg-doped hematite recorded in transmission geometry at 300?K. Black circles are the experimental data points and solid blue line is the Lorentzian fit.

New Journal of Chemistry, 2014

The present investigation describes the evolution of nanoiron oxide/oxyhydroxide phases synthesiz... more The present investigation describes the evolution of nanoiron oxide/oxyhydroxide phases synthesized under identical conditions of precipitation using different starting reagents.

Nanotechnology, 2006

... zinc ferrite MK Roy1, Bidyut Haldar2 and HC Verma1,3 1 Department of Physics, Indian Institut... more ... zinc ferrite MK Roy1, Bidyut Haldar2 and HC Verma1,3 1 Department of Physics, Indian Institute of Technology, Kanpur 208 016, India 2 Department of Physics, Institute of Engineering and Technology, CSJM University, Kanpur 208 024, India ... 233 Page 4. MK Roy et al ...

Nanotechnology, 2011

Electron-and ion-induced bending (EIB/IIB) phenomena have been studied in self-supported polycrys... more Electron-and ion-induced bending (EIB/IIB) phenomena have been studied in self-supported polycrystalline metallic and metal-amorphous bilayered nanocantilevers. The experiments reveal many interesting facts regarding electron/ion-matter interaction, which builds a proper foundation for the understanding of the phenomenon. The mechanism for bending of metallic cantilevers has been proposed to be primarily due to void-induced stress generation during ion beam irradiation. On the other hand, thermal effects have been found to play the dominant role in the case of bending of bilayer (amorphous-metal) nanocantilevers. The instantaneous, reversible, highly controllable and permanent nature of the process has been exploited to fabricate several complicated nanostructures in three dimensions. IIB of the fabricated cantilevers is shown to have a high precession mass sensing aptitude, capable of detecting a change in mass of the order of femtograms.

Micro & Nano Letters, 2011

... Vishwas N. Kulkarni at the initial stage of this work. We thank Prof. ... 287300 [3] Tripath... more ... Vishwas N. Kulkarni at the initial stage of this work. We thank Prof. ... 287300 [3] Tripathi SK, Shukla N., Rajput NS, Dhamodaran S., Kulkarni VN: &amp;amp;amp;amp;amp;amp;amp;amp;amp;#x27;Fabrication of nano-mechanical switch using focused ion beam for complex nano-electronic circuits&amp;amp;amp;amp;amp;amp;amp;amp;amp;#x27;, Micro Nano Lett., 2010, 5, pp. ...