JITENDRA GANGWAR
@rpsdegreecollege.org
Assistant Professor, Department of Physics
RPS Degree College, Balana, Mahendergarh (Haryana)
RESEARCH, TEACHING, or OTHER INTERESTS
Condensed Matter Physics, Energy, Materials Science
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Vartika Khandelwal, Piyush Siroha, S. Satapathy, Sonali Pradhan, Surendra Kumar, Narender Kumar, Jitendra Gangwar, S.K. Majumder, Ramovatar, and Neeraj Panwar
Elsevier BV
Priyanka Khaparde, Kamlesh S. Patle, Hitesh Borkar, Jitendra Gangwar, Anil K. Roy, and Vinay S. Palaparthy
Institute of Electrical and Electronics Engineers (IEEE)
It is pivotal to monitor and examine the plant disease during in situ measurements to abate the crop loss. For this purpose, leaf wetness sensors (LWS) are widely used. However, for the LWS during in situ measurements, operational exposure is always a concern considering the plant growth at different stages. During the plant growth, the stem angle changes and even the leaf canopy bends either inward or outward due to environmental factors or physical trauma. Thus, LWS placed on the leaf canopy may produce erroneous results. In this letter, we have examined the effect of leaf bending radius (outward or inward) and angle (from 0° to 90°) on the flexible LWS fabricated on the polyamide substrates. LWS comprises of interdigitated electrodes (IDEs) having interelectrode spacing 0.05 cm. Fabricated LWS are 3.5 cm long and 1.5 cm wide in dimension. We have used the two LWS viz. one bare IDEs and another with molybdenum disulfide (MoS2) coated LWS. Lab experiments indicated that sufficient wetness remained on the bare IDEs and MoS2-coated IDEs till 40° and 70° of bending angle, respectively. Subsequently, when the LWS are bended outward or inward, bare IDEs and MoS2-coated IDEs retain water molecules till 0.7 and 1 cm, respectively, when bended from its initial length (3.5 cm).
Manu Kumar Bhandoria, Ravi Kumar Rana, Yashpal Sharma, and Jitendra Gangwar
AIP Publishing
Naveen Kumar, Davender Singh, Rajesh Kumar, and Jitendra Gangwar
AIP Publishing
Jitesh Pani, Devkaran Maru, Priyanka Chaudhary, Jitendra Gangwar, Kanapuram Uday Kumar, Bal Chandra Yadav, and Hitesh Borkar
Wiley
Priyanka Khaparde, Kamlesh S Patle, Yash Agrawal, Hitesh Borkar, Jitendra Gangwar, Anil K Roy, and Vinay S Palaparthy
Institute of Electrical and Electronics Engineers (IEEE)
To abate crop loss, it is important to explore the plant disease management systems, where leaf wetness sensors (LWS) are widely used. The leaf wetness duration (LWD) extracted from the LWS is related to plant diseases. In this work, we have fabricated the LWS on the polyamide flexible substrate where Molybdenum disulfide (MoS2) is used as the sensing film to explore the leaf wetness sensing mechanism. Further, we have passivated the MoS2 with the help of acrylic protective lacquer (APL) conformal coating (MoS2 + APL), which reduce the interaction of the water molecules with the sensor. Lab measurements indicated that fabricated LWS on the flexible substrate with MoS2 and MoS2 + APL as the sensing film offers a response of about ≈ 40 000% and ≈ 250%, respectively, at 500 Hz excitation frequency when the entire sensing area is filled with the water molecule. The response time of the MoS2 and APL-coated flexible sensor is about 180 s. Fabricated LWS sensors offer hysteresis of about ± 4% in wetness. Further, we have identified that oxidation of the sulphur in the MoS2 plays an important role in the leaf wetness sensing mechanism. Furthermore, we understood that MoS2 when passivated with APL coating, the oxidation effect is reduced and the sensor response is negligible.
Naveen Kumar, Hitesh Borkar, Piyush Siroha, Rajesh Kumar, Kamlesh S. Patle, Kajal Kumar Dey, Yash Agrawal, Davender Singh, Yashpal Sharma, Ramovatar,et al.
Elsevier BV
Naveen Kumar, Piyush Siroha, Hari Shankar, Davender Singh, Yashpal Sharma, Rajesh Kumar, Ramovatar, Navneet Yadav, Kajal Kumar Dey, Hitesh Borkar,et al.
IOP Publishing
Abstract This paper reports the formation of flower-like hierarchical molybdenum disulfide (MoS2) nanoparticles following a simple one-step hydrothermal process with varying temperatures (200 °C and 220 °C). The as-synthesized particles were examined crystallographically by X-ray diffraction (XRD) method which revealed the formation of hexagonal MoS2 (2H-MoS2) and that the crystallite size of the particles increased with increasing hydrothermal temperature. Surface morphological characteristics of the particles were investigated by a field emission scanning electron microscope (FESEM) and interesting details were revealed such as the rounded 3D flower-like microstructure of the MoS2 particles and the petals of the flowers were composed of platelets built up by stacked-up MoS2 nanosheets. With the increase in hydrothermal temperature, the interlayer spacing of stacked layers of intense (002) plane is slightly decreased although the crystallinity of the material is improved. Both diameter and thickness of the nanoflowers and the nanoplatelets increased twice with increasing the temperatures. A visual crystallographic perspective was presented through simulation of 3D wireframe unit cell associated with the individual lattice planes as observed in the XRD pattern of the samples. In addition, a plausible growth mechanism is proposed for the formation of the obtained MoS2 nanoflowers on the basis of experimental observations and analysis.
Hitesh Borkar, Siju Mishra, Jitendra Gangwar, D. Haranath, and Ashok Kumar
Elsevier BV
Suman Gora, Lavanya Thyda, Gnyaneshwar Dasi, Reddivari Muniramaiah, Atul Thakre, Jitendra Gangwar, D. Paul Joseph, M. Kovendhan, P. Abdul Azeem, D. Dinakar,et al.
Elsevier BV
Yashpal Sharma, Ashok K. Sharma, Naveen Kumar, Rajesh Kumar, Piyush Siroha, and Jitendra Gangwar
Elsevier
Naveen Kumar, Piyush Siroha, Yashpal Sharma, Davender Singh, Kajal Kumar Dey, Rajesh Kumar, Hitesh Borkar, and Jitendra Gangwar
Elsevier BV
Amita, Asha, Vishakha, Neetu, Davender Singh, Naveen Kumar, Rajesh Kumar, and Jitendra Gangwar
AIP Publishing
The Patterson densities in terms of model electron densities and model nuclear densities have been performed on α-phase of Fe2O3. A theoretical work is carried out using VESTA software on the crystallographic visualization of Patterson densities of α-Fe2O3. The analyzed result mainly attributes to the packing fraction of α-Fe2O3 and is promising for the use of α-phase of Fe2O3 as ultraviolet (UV) blocking agent in paints.
Neetu, Devender Singh, Naveen Kumar, and Jitendra Gangwar
IOP Publishing
Herein, a comparative study of the various crystallographic characteristics of ZrO2 polymorphs has been carried for the monoclinic, tetragonal and cubic structures. First, different structural models are provided for apparent visualization of three ZrO2 polymorphs. The most intense lattice planes observed in all three ZrO2 polymorphs are then briefly covered. The model density, an essential feature to understand the atomic arrangements that depends on electron and nuclear distributions, is also compared in ZrO2 polymorphs. From these results, we suggest that this approach is a remarkable importance of polymorphs ZrO2, which is one of many stable oxides in Zr–O chemistry. The crystallography characteristics are, therefore, suitably simple to analyze the utility of the approach.
Naveen Kumar, Davender Singh, Parveen Kumar, and Jitendra Gangwar
AIP Publishing
Piyush Siroha, Davender Singh, Rakhi Soni, and Jitendra Gangwar
Author(s)
Over the past decades, a rapidly increasing interest towards miniaturization of electronic devices, structures with a size in the nanometer realm have perked up intensive and worldwide research activities in transition metal oxides nanostructures (TMONs). Various TMONs (NiO, CuO, ZnO, TiO2, ZrO2, VO2, V2O5, Fe2O3 etc.) have excellent properties such as unique crystal structure, multi dimensionality and quantum size confinement effects. Currently they are the most promising oxides with Polymorphism (materials with same composition and different crystal structures) property and applied as sensors, impurity separators and electronic components, in magnetic storage, recording media, as well as antimicrobial agents for diagnosis of diseases, drug delivery systems, sun screens and ceramics in biomedical and pharmaceutical arena. Both experimental and theoretical aspects of highly ordered TMONs (in particular Fe2O3 and TiO2) assemblies have received a great deal of attention in recent years. With the advancement of nanoscience and nanotechnology, the present work comprise of crystallographic representation of polymorphs Fe2O3 (α-Fe2O3) and TiO2 (anatase-, brookite-, and rutile-TiO2) nanomaterials using VESTA software. Herein, we constructed the visualization of different parameters in terms of crystal structures and lattice planes for transition metal oxide polymorphs material in particular Fe2O3 and TiO2. By using VESTA software, we calculated the bond-length of iron (Fe) and titanium (Ti) materials with oxygen (O) and the calculated bond-length is in angstrom. This research work attempts to mainly elaborate the crystallographic information of Fe2O3 and TiO2 polymorphs and their plausible potentials in bio-safety, health and drug delivery applications.Over the past decades, a rapidly increasing interest towards miniaturization of electronic devices, structures with a size in the nanometer realm have perked up intensive and worldwide research activities in transition metal oxides nanostructures (TMONs). Various TMONs (NiO, CuO, ZnO, TiO2, ZrO2, VO2, V2O5, Fe2O3 etc.) have excellent properties such as unique crystal structure, multi dimensionality and quantum size confinement effects. Currently they are the most promising oxides with Polymorphism (materials with same composition and different crystal structures) property and applied as sensors, impurity separators and electronic components, in magnetic storage, recording media, as well as antimicrobial agents for diagnosis of diseases, drug delivery systems, sun screens and ceramics in biomedical and pharmaceutical arena. Both experimental and theoretical aspects of highly ordered TMONs (in particular Fe2O3 and TiO2) assemblies have received a great deal of attention in recent years. With the advancement...
Davender Singh, Virender Singh Kundu, R. L. Dhiman, and Jitendra Gangwar
Author(s)
Zn-doped SnO2 nanoparticles were synthesized successfully by Sol-Gel technique with different doping concentration of zinc. The calcined nanoparticles at 400°C, were characterized by means of X-ray diffraction (XRD). XRD analysis reveals that the nanoparticles of various doping concentration are polycrystalline in nature and existed as tetragonal rutile structure. The particle size of the nanoparticles was calculated by Scherrer formula and was found in the range of 7-24 nm. The morphology and nature of nanoparticles was analyzed by using scanning electron microscope (SEM), study of images confirms the existence of very small, spherical and unvaryingly distributed crystalline nanoparticles. Energy dispersive X-ray (EDX) analysis confirms the presence of zinc. The formation of Sn–O phase and hydrous nature of pure and Zn-doped SnO2 nanoparticles were confirmed by FTIR study.Zn-doped SnO2 nanoparticles were synthesized successfully by Sol-Gel technique with different doping concentration of zinc. The calcined nanoparticles at 400°C, were characterized by means of X-ray diffraction (XRD). XRD analysis reveals that the nanoparticles of various doping concentration are polycrystalline in nature and existed as tetragonal rutile structure. The particle size of the nanoparticles was calculated by Scherrer formula and was found in the range of 7-24 nm. The morphology and nature of nanoparticles was analyzed by using scanning electron microscope (SEM), study of images confirms the existence of very small, spherical and unvaryingly distributed crystalline nanoparticles. Energy dispersive X-ray (EDX) analysis confirms the presence of zinc. The formation of Sn–O phase and hydrous nature of pure and Zn-doped SnO2 nanoparticles were confirmed by FTIR study.
Rajni Verma, Jitendra Gangwar, and Avanish K. Srivastava
Royal Society of Chemistry (RSC)
This review article provides an exhaustive overview of efficient synthesis, growth mechanism and research activities of multiphase TiO2nanostructures to provide their structural, morphological, optical and biological properties co-relations.
Jitendra Gangwar, Bipin Kumar Gupta, and Avanish Kumar Srivastava
Defence Scientific Information and Documentation Centre
<p>This review article mainly focused on the recent progress on the synthesis and characterization of emerging artificially engineered nanostructures of oxide materials as well as their potential applications. A fundamental understanding about the state-of-the-art of the synthesis for different size, shape and morphology, which can be tuned to the desired properties of oxide nanomaterials have discussed in details in this review. The present review covers the a wide range of artificially engineered oxide nanomaterials such as cadmium-, cupric-, nickel-, magnesium-, zinc-, titanium-, tin-, aluminium-, and vanadium-oxides and their useful applications in sensors, optical displays, nanofluids and defence.</p>
Achu Chandran, Jai Prakash, Jitendra Gangwar, Tilak Joshi, Avanish Kumar Srivastava, D. Haranath, and Ashok M. Biradar
Royal Society of Chemistry (RSC)
A low-power nonvolatile memory device is fabricated by dispersing nickel oxide nanorods (nNiO) into a ferroelectric liquid crystal (FLC) host. The dipolar nNiO adsorbed ions in the FLC and thereby reduced the screening effect, which resulted in the enhanced memory behavior.
Gaurav Jamwal, Jai Prakash, Achu Chandran, Jitendra Gangwar, A. K. Srivastava, and A. M. Biradar
AIP Publishing LLC
In the present paper, we have studied the improvement in dielectric and optical properties of nematic liquid crystal (NLC) by doping of nickel oxide (NiO) nanoparticles. We have observed the dielectric and optical properties of pure and doped cells in order to understand the influence of NiO nanoparticles in the pure NLC. The experimental results have been analyzed through dielectric spectroscopic and optical texural methods.Detailed studies of dielectric parameters such as dielectric permittivity, dielectric loss and dielectric loss factor as a function of frequency with temperature were carried out. It has been observed that on doping the nanoparticles in NLC, the value of dielectric parameters (dielectric permittivity, dielectric loss and dielectric loss factor) decreases. The impedance and resistance of both pure and nanoparticles doped NLC cells were studied and found that for doped NLC, these parameter have low value. In addition to this, optical textures of the pure and doped samples have also been observed with a polarizing optical microscope at room temperature. All the results i.e. related to the investigation of dielectric and electro-optic properties have been explained by using existing theory of NLC.In the present paper, we have studied the improvement in dielectric and optical properties of nematic liquid crystal (NLC) by doping of nickel oxide (NiO) nanoparticles. We have observed the dielectric and optical properties of pure and doped cells in order to understand the influence of NiO nanoparticles in the pure NLC. The experimental results have been analyzed through dielectric spectroscopic and optical texural methods.Detailed studies of dielectric parameters such as dielectric permittivity, dielectric loss and dielectric loss factor as a function of frequency with temperature were carried out. It has been observed that on doping the nanoparticles in NLC, the value of dielectric parameters (dielectric permittivity, dielectric loss and dielectric loss factor) decreases. The impedance and resistance of both pure and nanoparticles doped NLC cells were studied and found that for doped NLC, these parameter have low value. In addition to this, optical textures of the pure and doped samples have also been...
Jitendra Gangwar, Bipin Kumar Gupta, Surya Kant Tripathi, and Avanish Kumar Srivastava
Royal Society of Chemistry (RSC)
In this review, we discuss new developments and recent trends in both amorphous and crystalline Al2O3 oxide nanofluids related to their phase dependent characteristics in detail. Nowadays, nanofluids have gained significant attention with the enhanced energy/heat efficiency, which is highly desirable to improve the performance of any energy based devices and technology. This review article systematically describes the various chemical synthesis routes followed by bottom-up approaches, surface morphologies, and detailed microstructure characteristics, and phase dependent thermal as well as optical properties for potential use of such materials in various applications.
Jitendra Gangwar, Achu Chandran, Tilak Joshi, Rajni Verma, Ashok M Biradar, Surya Kant Tripathi, Bipin Kumar Gupta, and Avanish Kumar Srivastava
IOP Publishing
Herein, we have investigated the various characteristics of two structurally different phases of Al2O3 nanowires: (i) γ-Al2O3 (cubic) and (ii) θ-Al2O3 (monoclinic). These nanowires were synthesized via hydrothermal treatment followed by calcination. The structural and luminescent properties were analyzed by scanning electron microscopy, high-resolution transmission electron microscopy and time-resolved photoluminescence spectroscopy. A plausible formation mechanism was proposed on the basis of experimental observations and analysis. These nanowires of both phases exhibit blue emission at ∼466 nm (2.65 eV) upon 253 nm UV excitation wavelength. The time-resolved photoluminescence spectroscopy indicated that the decay time (τ) of θ-Al2O3 nanowires (τ = 273 picoseconds) is longer than that of γ-Al2O3 nanowires (τ = 198 picoseconds). Moreover, these Al2O3 nanowires were dispersed in ferroelectric liquid crystal (FLC) to observe their effect on the electro-optical characteristics. The electro-optical response of the composite devices showed faster electro-optical response, thereby suggesting potential applications in electro-optical shutters and modulators.
Jitendra Gangwar, Bipin Kumar Gupta, Pawan Kumar, Surya Kant Tripathi, and Avanish Kumar Srivastava
Royal Society of Chemistry (RSC)
Herein, we have demonstrated the high yield facile growth of Al2O3 nanowires of uniform morphology with different polymorph phases (e.g. γ, δ and θ) via a hydrothermal method with varying calcination temperatures. The synthesized θ-Al2O3 nanowires were well characterized by XRD, FTIR, SEM/EDAX, AFM and HRTEM techniques. Microstructural analysis confirmed that the dimensions of the individual θ-Al2O3 nanowires are approximately in the ranges 5-20 nm in width and 40-150 nm in length, and the aspect ratio is up to 20. AFM results evidenced the uniform distribution of the nanowires with controlled morphology. Furthermore, UV-vis spectroscopic data reveal that the estimated optical band gap of the θ-Al2O3 nanowires was ~5.16 eV. The photoluminescence spectrum exhibits blue emission upon excitation at a wavelength of 252 nm. Time-resolved spectroscopy demonstrates that these nanowires illustrate a decay time of ~2.23 nanoseconds. The obtained photoluminescence results with a decay time of nanoseconds suggest that the θ-Al2O3 phase could be an exceptional choice for next generation fast optical sensors.
J. Gangwar, A. K. Srivastava, S. K. Tripathi, M. Wan, and R. R. Yadav
AIP Publishing
In the present work, the temperature and concentration dependence of thermal conductivity (TC) enhancement in ethylene glycol (EG)-based amorphous and crystalline Al2O3 nanofluids have been investigated at temperatures ranging from 0 to 100 °C. In our prior study, nanometer-sized particles of amorphous-, γ-, and α-Al2O3 were prepared via a simple sol-gel process with annealing at different temperatures and characterized by various techniques. Building upon the earlier study, we probe here the crystallinity, microstructure, and morphology of the obtained α-Al2O3 nanoparticles (NPs) by using X-ray powder diffraction with Rietveld full-profile refinement, scanning electron microscopy, and high-resolution transmission electron microscopy, respectively. In this study, we achieved a 74% enhancement in TC at higher temperature (100 °C) of base fluid EG by incorporating 1.0 vol. % of amorphous-Al2O3, whereas 52% and 37% enhancement is accomplished by adding γ- and α-Al2O3 NPs, respectively. The amorphous phase of NPs appears to have good TC enhancement in nanofluids as compared to crystalline Al2O3. In a nutshell, these results are demonstrating the potential consequences of Al2O3 NPs for applications of next-generation efficient energy transfer in nanofluids.