Monika Goyal

GLA University · Department of PHYSICS

In the present paper, a simple qualitative model is proposed to study the effect of dimension and crystal structure on the energy band gap of semiconducting nanomaterials. The energy band gap variation is studied for nanoparticles, nanowires and thin films. The model takes into account the crystal structure and to incorporate the effect of crystal...

This study assesses the dosimetric effectiveness of the commercial trade-offoptimization (TO) module in comparison to iterative optimization for volumetric modulated arc therapy (VMAT) in craniospinal ir- radiation technique. Fifteen patients who had previously undergone VMAT-based craniospinal irradiation (CSI) using manual optimization (TP) under...

Objectives The aim of this study was to determine the number of trade-off explored (TO) library plans required for building a RapidPlan (RP) library that would generate the optimal clinical treatment plan. Methods We developed 2 RP models, 1 each for the 2 clinical sites, head and neck (HN) and cervix. The models were created using 100 plans and w...

Abstract: Background: In healthcare, machine learning is playing a significant role in computer-aided detection and diagnosis of lung nodules to reduce the load and increase the accuracy of radiologists. In the scenario where the datasize is limited, machine learning poses its advantage. The intrinsic information is discerned utilizing radiomics, w...

The variation in bandgap energy with decreased size and varying composition of alloys has attracted the attention of researchers over the past few decades. In the present paper, a simple unified model is presented to study the impact of alloying on the bandgap energy of ternary semiconducting compounds with varying composition. The energy bandgap i...

Introduction: The objective of the present study is to classify chest X-ray (CXR) images into COVID-positive and normal categories with the optimal number of features extracted from the images. The successful optimal feature selection algorithm that can represent images and the classification algorithm with good classification ability has been det...

Purpose The purpose of this study is to evaluate the dosimetric and treatment delivery characteristics of volumetric modulated arc therapy technique (VMAT)-based craniospinal axis irradiation (CSI) between ring gantry Halcyon (HAL) and C-arm based Novalis Tx (NTx) linear accelerator. Set-up margin and treatment delivery time for both machines were...

In the present study, a phenomenological model based on thermodynamic variables is developed to study the thermophysical properties of nanomaterials with respect to size in nanoscale. The model input parameters are lattice packing fraction depending on crystal structure and atomic diameter of nanosolid. The shape parameter is incorporated in the mo...

A simple unified thermodynamic approach is developed to determine the effect of size on Raman frequency of nanomaterials. The model approach is based on the Bond energy model developed to determine cohesive energy of nanomaterials with respect to bulk material. The model formulation includes the size, dimension and shape of nanomaterial. The model...

In the present work, the author focussed on the electrical properties of nanostructures. A qualitative model is extended to obtain the expression of thermal conductivity of nanosolid. Using the Wiedemann-Franz law, electrical conductivity and then expression of electrical resistivity is obtained. The inclusion of scattering term in the calculation...

In the present study, a simple model is presented to study the shape, size and dimension effect on the bulk modulus of nanomaterials. The bulk modulus dependence on group velocity and mass density of material is taken into account. A qualitative melting temperature model for nanocrystals is extended to express the bulk modulus of nanocrystal in ter...

In the present paper, a theoretical model is used to study the optical properties of nanomaterials. The optical properties of nanosized semiconductors are studied in relation to dimension and size. The model proposed by Guisbiers is extended to study the impact of size and shape on band-gap expansion, dielectric constant, vibrational frequency and...

In the present study, a simple model is developed to determine the variation in dielectric constant with size and shape in nanosolids. The dielectric properties are investigated with respect to the size and composition of the nanoalloys. The variation in dielectric constant in nanosized semiconducting compounds of ZnS, CdS, CdSe, CdTe and their nan...

In the present study, the thermal conductivity relation equation given by Leibfried and Schlomann is extended and thermal conductivity is estimated at different pressures and temperatures by predicting the variation of Debye temperature, Gruneisen parameter and volume compression with temperature and pressure. The change in volume under variable pr...

A theoretical formulism is developed to study the impact of temperature and pressure on nanomaterials. Here Shankar equation of state for solids is extended using an analytic model given by Jiang for nanomaterials. The effect of size, dimension and orientation of nanomaterial on the elastic properties is studied. Bulk modulus is found to decrease a...

In the present study, a thermodynamical formulation is developed to determine the melting temperature of alkali halides with increasing pressure. The model is used to estimate the melting temperature of alkali halides at different pressures qualitatively. The formulation is obtained using the Goyal and Gupta thermodynamic equation of state. The mod...

A simple unified model is used to study the variation in Debye temperature in monometallic and bimetallic nanoalloys. In the present study, a systematic investigation of variation in Debye temperature is done to analyze the impact of size, shape, composition and dimension in monometallic and bimetallic nanoalloys. It is found that Debye temperature...

Three different models, viz. Qi model, Jiang model and Lu model, have been used in the present paper for studying the size and shape dependence of magnetic properties of the nanomaterials. The magnetic properties considered here are Curie temperature \((T_{\mathrm {C}})\), magnetisation \((M_{\mathrm {S}})\) and Neel temperature \((T_{\mathrm {N}})...

The study of defects or vacancies helps to understand the transport mechanism that occurs electrically and thermally in materials. It also deals with the mechanical properties of materials. In the present study, the extension of qualitative size-dependent model proposed by Jiang for cohesive energy of nanomaterials is done and size dependence of va...

Purpose: The purpose of this study is to analyze the utility of Convolutional Neural Network (CNN) in medical image analysis. In this study, deep learning (DL) models were used to classify the X-ray into COVID, viral pneumonia, and normal categories. Materials and methods: In this study, we have compared the results 9 layers CNN model (9 LC) dev...

In the present paper, we have studied the dependence of thermal conductivity on shape, size and dimension of nanomaterial. By using the quantitative expression of melting temperature, the expression for thermal conductivity is deduced in this work. Kapitza resistance term is also considered in the study to better explain the thermal conductivity va...

The phenomological model for cohesive energy of metallic nanomaterials is extended to investigate the variation in thermodynamic properties of bimetallic nanostructures. The systematic investigation of variation in melting temperature of bimetallic nanomaterials is done to study the impact of size, composition and dimension. Decrease in melting tem...

In the present work, we have used phenomological models for analyzing the impact of shape and size on energy band gap in semiconducting nanomaterial compounds. The models used presently are Qi model, Bond energy model and Guisbiers model. The extension of melting temperature expression for nanomaterials of the models considered is done and shape an...

Carbon nanostructures have been fascinating mankind since their discovery. Their excellent biocompatibility and toughening properties can virtually reinforce any material. Glass ionomer (GIC) dental cement is bestowed with numerous advantages like anti-caries action, adhesion to a tooth, etc. But, due to its low mechanical properties, it is not the...

In the present study, a theoretical comparative work is done to calculate the variation of melting temperature in nanomaterials by using two quantum models i.e. Lu model and Jiang model and the expression of melting temperature calculated with the help of best model is extended to calculate the variation of Debye temperature and thermal expansion c...

For estimating capabilities of cooling in case of nano fluid materials experiments such as forced convective for steady state have been conducted made of two different Carbon nanomaterials, Multi-Walled Carbon Nano Tubes (MWCNT) and Multi-Walled Carbon Nano Coils (MWCN). Nanomaterials have been synthesized in house and they are denoted using the SE...

A theoretical quantitative model is used in the present work to analyze the size and shape effect on Curie temperature in nanomaterials. The model used here is given by Qi in terms of cohesive energy which is extended to obtain the expression of Curie temperature in terms of shape factor and size. The results depict that Curie temperature in nanoma...

In the present study, a comparative study of thermodynamic properties of nanomaterials, i.e. melting entropy and melting enthalpy is done to analyze the size, shape and dimension effect on them. The models used for the study are Qi model, Guisbiers model and Liquid drop model. The relation of melting entropy and enthalpy are obtained using expressi...

In this paper, Ni-Al compound coatings were electrodeposited from a nickel sulphate electrolyte containing metallic Al particles (1-3um). The deposition conditions adopted were: compound content 50 g/l, pH 4.0, and present density 1.6A/dm'. At electrode position, the particles were held in suspension by magnetic stirring. The deposition was carried...

In the present work, the dependence of thermodynamic properties on shape, size and dimension of the nanomaterials is studied. The theoretical model proposed by Lu et al. is used in the present work and the model is extended to calculate the variation in Young’s modulus and vibrational frequency with size of the nanomaterial for spherical, hexahedra...

In the present study, a thermodynamic model is formulated to determine the melting temperature of metals with increasing pressure using an equation of state (EoS). The model is applied to determine the melting temperature of Cu, Au, Ag, Zn, Cd, In and Pb at high pressure. The model formulation is based on Goyal and Gupta EoS which follows Stacey's...

A phenomenological model based on thermodynamical variables is used to analyze the optical properties of nanomaterials. The expression of cohesive energy given by Qi and Wang model is extended to study the variation of the energy band gap, vibrational frequency, and static dielectric constant with size for nanoparticles, nanowires, and nanofilms. T...

A simple model based on thermodynamic variables is used to study the effect of shape, size and structure on the various thermodynamic properties of nanowires. The expression of cohesive energy derived by Qi and Wang [16] is used and ratio of surface atoms to total number of atoms is expressed in terms of shape parameter, radius of nanowire and atom...

The impact of shape, size and temperature on elastic properties of nanomaterials is studied in this work. We have extended the melting temperature expression for nanostructures formulated by Guisbiers et al. and obtained the expression of elastic moduli and thermal expansivity for nanomaterials. An isobaric Tait equation of state is combined with G...

A phenomological model is described here to study the effect of size, shape and phonon scattering on the thermal conductivity of nanostructures. Using the classical model proposed by Guisbiers et al (Phys. Chem. Chem. Phys. 12, 7203 (2010), J. Phys. Chem. C 112, 4097 (2008)) in terms of the melting temperature of nanostructures, the expression for...

In the present study, the expression of first pressure derivative of bulk modulus B′ earlier derived by Goyal and Gupta EoS [7] is corrected and the validity of the EoS is then verified in extreme compression region. The expressions of second and third order pressure derivative (B″,B″′)of bulk modulus are obtained. The values of B′ B²B‴ to BB″ Grun...

A theoretical model is described here for studying the effect of temperature on nanomaterials. The thermodynamic equation of state (EoS) proposed by Goyal and Gupta in High Temp.-High Press. 45, 163 (2016); Oriental J. Chem. 32(4), 2193 (2016), is extended in the present study using Qi and Wang model [Mater. Chem. Phys. 88, 280 (2004)]. The thermal...

The size- and shape-dependent band gap energy of semiconductor compound nanomaterials (SCNs) is formulated. The model theory is based on the cohesive energy of the nanocrystals compared to the bulk crystals. We have considered CdSe, CdTe, ZnS, ZnSe and ZnTe semiconductors compounds for the study of size- and shape-dependent band gap energy. It is f...

A theoretical model is proposed for the study of size and shape dependent thermal-optical properties of group III wurtzite type nitride nanomaterials. The model proposed is used to calculate the variation in melting temperature, cohesive energy, Debye temperature and energy band gap in AlN, GaN, InN nanostructures in spherical form, nanowire shaped...

A temperature dependent model is formulated to study the thermo-elastic properties of nanomaterials. The model is based on quasi-harmonic approximation and Anderson Gruneisen parameter is considered to vary with temperature linearly. Present model is the modified form of the equation of state (EoS) recently developed by Goyal and Gupta to explain t...

A theoretical model based on thermodynamic variables is employed in the present work to study the thermophysical properties of nanomaterials of different shapes and sizes. The model proposed by Qi and Wang [19] is applied to determine the cohesive energy of nanomaterial. The number of atoms on the surface to the total number of atoms in nanosolid i...

The journal transferred to Taylor and Francis effective 1 January 2018 and all Articles in Press will be published by the new publisher as a result. This Article in Press has therefore been withdrawn from this platform. Should you have any queries please contact the Managing Editor Dr. Moustafa El-Naggar at moustafael_naggar@hotmail.com. The full E...

A new potential independent equation of state is used in the present work to analyze the thermo-elastic properties of nanocrystalline foresterite (nc- Fo) under varying temperature and pressure conditions. The newly developed EOS is found to be valid for explaining the elastic behavior of nanocrystalline forsterite satisfactorily over the temperatu...

The temperature dependent equation of state(EOS) is developed in the present work to analyze the thermo-elastic properties of solids. The new EOS is formulated by modifying the pressure dependent form of EO Sreported recently by the present authors to explain the elastic behavior of nano materials. The values of thermal expansion are calculated for...

In the present paper, it is shown that the equation of state (EOS) [10,11] described earlier on the basis of the Gruneisen theory of thermal expansivity is mathematically and thermodynamically inconsistent. This inconsistency is corrected by Kholiya [12] using the expansion of PV2 in powers V of (1-V/V0) up to the quadratic term. However, in the pr...

The high pressure compression behavior of various nanomaterials have been studied using isothermal equations of state, i.e. Usual Tait's equation, Sharma and Kumar EOS, and modified Usual Tait's equation. The results obtained from the modified usual Tait's equation are compared with the other equations of state considered and also with the availabl...

This paper reports the results of a theoretical investigation on the compress ional behavior of ZnO nanostructures like ZnO-nanowire, ZnO-nanotube and ZnO-nanorods at high pressure during transformation from wurtzite to rock salt structure. A simple theory is proposed to predict the transition pressure (PT) of these nanomaterials, which gets suppor...