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Study on Graphs Associated with Groups
In this dissertation, the notions of non-inverse graphs, order sum graphs and coset newlinecomponent graphs associated with groups are introduced. These graphs are simple graphs whose vertices are the elements of the group and the adjacency between the vertices depends on certain properties of the group concerned. Vertices belonging to non-inverse graphs are adjacent if they are not inverses of each other in the group. The vertices in order sum graphs are adjacent if the sum of their orders is strictly greater than the order of the group. The vertices belonging to the coset component graphs are adjacent if their left cosets or right cosets of the subgroups of groups are equal. These algebraic graphs are studied in detail in terms of their structural characteristics, parametric properties and spectral properties. Various characterisations of these graphs are obtained in the study concerned. These notions are further extended to the concept of signed graphs and domination. Properties of signed graphs such as balance, clusterability, consistency, sign-compatibility and so on are investigated for these algebraic signed graphs. The relations between various types of domination are obtained for non-inverse graphs, order sum graphs, complement and line graphs of order sum graphs. -
Study on Falkner-Skan Flow of MWCNT-MgO/ EG Hybrid Nanofluid
In this chapter, a theoretical study of the Falkner-Skan flow and heat transport of a Newtonian ethylene glycol containing MWCNT-MgO hybrid nanoparticles on a wedge-shaped surface using the modified Buongiorno nanofluidic model (MBNM) is performed. The mechanisms of Brownian motion (BM) and microscopic thermophoresis (MT) of solid nanoparticles are implicitly included together with the thermophysical properties. The effects of thermal radiation, the Lorentz force, and Joule heating are examined. The passive control of the nanoparticles and the thermal jump boundary conditions are considered. The governing equations are modeled using the conservation of mass, the Navier-Stokes equation, the conservation of energy, and the conservation of nanoparticle volume fraction. The Prandtl boundary layer and Rosseland heat flux approximations were used. The velocity, temperature, and volume fraction of nanoparticles behaviors are analyzed for various parameters. It is determined that the temperature of the hybrid nanofluid increased due to the presence of Joule heating, radiative heat flux, Brownian motion, and thermophoresis aspects in the system. Furthermore, a hybrid nanoliquid exhibits a higher heat transfer rate than mono nanoliquid and base fluid. 2024 selection and editorial matter, Katta Ramesh, Fateh Mebarek-Oudina, and Basma Souayeh; individual chapters, the contributors. -
Study on factors influencing purchase of branded formal apparel in Indian apparel industry /
International Journal of Business, Management & Social Sciences, Vol-3 (5(2), pp. 51-54. ISSN-2249-7463. -
Study on Effect of Overdraft facility on market liquidity and income of private banks in Bangalore
This Dissertation depicts about the use of overdraft facility by the business men/women as customers of the private banks and how it affects the liquidity status and income of those private banks in Bangalore. This study helps the private bankers to identify the financial changes in the annual reports supported by statistical tools depicting the significant changes in relation to market liquidity and the income of the private banks. An overdraft allows an individual to continue withdrawing money even if the account has no funds in it and the bank will cover the checks which would otherwise bounce. The interest on the outstanding balance of an overdraft loan often is lower than credit cards. Market Liquidity is an asset's ability to be sold without causing a significant movement in the price and with minimum loss of value. Referring this meaning to the banks, overdraft plays a small part in changing the interest rates and also incurring a very minimal expense to maintain the OD account for the customers among the banks compared to cash credits and loan repayable on demand which are the major reasons for the influence on bank rates. In order to provide for the overdraft facility to the customers, even though for period of 22 days up to 45 days depending on the respective banks policies, banks must maintain a ready source to compensate the customers demand to withdraw beyond a nil balance. Thus Total Deposits are considered to represent the market liquidity of the banks. Income of private banks mainly in connection to the topic of the study considers only the interest earned on the overdraft for approximate comparison between the overdraft balance and interest earned on it. Thus giving no grounds for confusions as to why net profit or income earned through other sources is not considered. Reason for taking the liquidity and income to compare it with overdraft is that all three factors are of shorts terms in nature. It gives a common ground for significant comparison. It also provides appropriate data for correct statistical analysis giving accurate result. While increase in overdraft balance increases the interest amount earned on it or the banks have to increase the deposits to provide for the increasing overdraft balances. Other than the problem of the study, smooth or turbulent financial periods, behaviour of funds rate in response to declining required reserves, political scandals, bad cheques etc. are the various factors practically influencing the overdraft to affect the private banks market liquidity and income The scope of the study reckons to give the results as an answer for various queries of not only to the selected sample private banks but also to other banks that are providing the overdraft facility. It also helps the other researchers to carry on the further study. The hypothesis is to prove whether or not the overdraft affects the market liquidity and income. Sample size N=20 taken for data analysis includes the five years of the three variables of the study from 17 NSE Listed and 3 non listed private banks located in Bangalore which are available from annual reports the websites of sample banks, pay sites like report junction and CMIE-business beacon. This sample size is accumulated through convenient sampling of non-probabilistic sampling technique. Mainly Correlation is used as Statistical Technique for analysis and other than that, financial analytical tools are also employed i.e. Growth analysis, Peer group comparison and Industrial benchmarking. Through correlation analysis, findings are drawn that the effect of overdraft on market liquidity and as well as the effect of overdraft on income of the 20 banks are highly significant (p<0.01). Thus, the null hypothesis 1 and 2which shows that overdraft does not affect the market liquidity and income is proved otherwise. Increase in overdraft does affect the market liquidity and income positively. -
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Study on academics and stress during Covid-19 outbreak
The objectives of the study were to identify and analyze the leading causes of academic stress that may have significant effects on the success and well-being of students and explore the significant sources of stress among students during their studies during the COVID-19 outbreak. The study was also conducted to understand if their gender-wise differences on the basis of academic stress reported. The sample consisted of 100 students and 15 sources of stress divided into three categories: relations with other people, personal factors, and academic factors. results show the academic sources of stress appeared to be the most stressful for all the students due to the pressure originated from the course overloads and the academic evaluation procedures. The findings from this study may be useful for further research on how these potential sources of stress influence the performance and the health of the students. 2021 Ecological Society of India. All rights reserved. -
Study on 5G Massive MIMO Technology Key Parameters for Spectral Efficiency Improvement Including SINR Mapping on Rural Area Test Case
Massive MIMO is one of the key disruptive technologies in 5G which offers significant change in the core network architecture and channel modeling compared to the previous wireless communication standards. There are many research works currently focusing on implementing Massive MIMO network in different channel propagation models. ITU, 3GPP and IMT consortium deliver timely 5G LTE releases and taken as benchmark documents by various telecom companies and universities to set up testing, trials and hardware deployments. However, without optimization on spectral efficiency parameter, the specifications proposed by 5G in terms of improvement in data rate or throughput could be difficult to achieve. This paper initially provides an in-depth study on spectral efficiency estimation and optimization in Massive MIMO by investigating different research papers. From these papers, list of parameters involved in spectral efficiency are identified, such as, fading characteristics, power or energy efficient parameters, standard deviation, angle of arrival factors in antennas installed in base stations and many others. The author however concludes with the best selection of constraint optimization parameters to improve the spectral efficiency taking into account of its simple design and major impact on the improvement in the result by taking downlink scenario of a simulation environment using 5G Massive MIMO network. SINR mapping of standard Rural Macro test scenario adopted from M 2314, LTE release 17 of 5G framework is simulated in this research paper. 2022 IEEE. -
Study of X-Ray Intraday Variability of HBL Blazars Based on Observations Obtained with XMM-Newton
We present an extensive study on the X-ray intraday variability of 10 teraelectronvolt-emitting high synchrotron peaked blazars (HBLs): 1ES 0229+200, 1ES 0414+009, PKS 0548-322, 1ES 1101-232, 1H 1219+301, H 1426+428, Mrk 501, 1ES 1959+650, PKS 2005-489, and 1ES 2344+514 made with 25 XMM-Newton pointed observations during its operational period. Intraday variability has been estimated in three energy bands: soft (0.3-2 keV), hard (2-10 keV), and total (0.3-10 keV). Although seven out of 10 teraelectronvolt HBLs exhibited some intraday variability at 3? levels, no major variations exceeding 6% were detected. We explored the spectral properties of the sample by extracting the hardness ratio from the soft and hard bands; no significant variations in the hardness ratio were observed in any source. We performed power spectral density analyses on the variable light curves by fitting power laws, yielding slopes lying in the range of 1.11-2.93 for different HBLs. We briefly discuss possible emission mechanisms and carry out rough estimates for magnetic fields, electron Lorentz factors, and emission region sizes for seven of these HBLs. 2022. The Author(s). Published by the American Astronomical Society. -
Study of two-dimensional, all-time dispersion of a solute in a fluid-saturated porous medium
The effect of interphase mass transfer on dispersion in a unidirectional flow through a horizontally extent of infinite porous channel is examined using the generalized dispersion model of Sankarasubramanian and Gill [91]. The model brings into focus three important coefficients namely the exchange coefficient, the convection coefficient and the dispersion coefficient. The exchange co- efficient exists due to interphase mass transfer. The effects of reaction rate parameter, ? porous parameter, ? and Brinkman number, ??, on the veloc- ity and thereby the convective and dispersion coefficients are discussed. The time-dependent dispersion coefficient and mean concentration distribution are computed and results are represented graphically for various values of ? ? and ??. The results have applications in heat exchangers, petroleum and chemical engineering problems, chromatography and bio-mechanical problems. -
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Study of triple diffusive convection in non newtonian liquids
This thesis presents the study of triple diffusive convection in two nonNewtonian liquids couple stress liquid and viscoelastic liquid of type Oldroyd-B in the presence of external constraints like rotation, gravity modulation and temperature modulation. Linear stability analysis provides the stability condition of stationary and oscillatory convection and the resultant eigen function describes the newlineconvective flow. However, linear analysis can neither help to examine the rate newlineof heat and mass transfer nor provides information on the convection newlineamplitudes. Therefore, it is also important to do nonlinear analysis. In view of newlinethis, all the problems considered in this thesis are studied for both linear and newlinenonlinear cases. The eigen value arising in the linear case for the problems newlinewithout modulation is solved by normal mode technique whereas for the problems with modulation is solved by perturbation method by adopting Venezian approach. The nonlinear study is done by using Ginzburg Landau newlinemodel for the problems with couple stress liquid whereas the nonlinear study is done by truncated representation of Fourier series by Lorenz model for the problems with viscoelastic Oldroyd-B liquid. The present study has wide range of applications in material processing, solidification of alloys, underground spreading of chemical pollutants, petroleum reservoirs, cooling of electronic devices, thermal insulation newlinematerial, crystal growth, transport of chemical substances, solar receivers, newlineinjection moulding, chemical industries, nuclear industries, bioengineering, newlineoceanography, meteorology, astrophysics, geophysics and so on. The extensive description of wide-ranging applications of triple diffusive convection in non-Newtonian liquids is accountable for the motivation of this thesis. The following four problems are carried out in this thesis: (i) EFFECT OF ROTATION ON TRIPLE DIFFUSIVE CONVECTION IN COUPLE STRESS LIQUID The effect of rotation on triple diffusive convection in couple newlinestress liquid is considered. -
Study of Transport Characteristics using Impedance Spectroscopy and Memristor Property Analysis of Protonated Polyaniline-WO3 Nanocomposite
Polyaniline-WO3 nanocomposite was synthesized through in-situ chemical polymerization. The structural properties are studied by using XRD and FESEM characterization. The XRD results confirmed the presence of crystalline WO3 nanoparticles in the polymer nanocomposite structure. FESEM images confirmed the sheet-like structure with heterojunction of WO3 nanoparticles and polyaniline matrix. The transport properties of the synthesized nanocomposites are studied using impedance spectroscopy analysis. The complex impedance analysis conducted using the Nyquist plot and equivalent circuit model of the nanocomposites are simulated using ZSimpWin software. The major conduction mechanism in the material is found to be grain boundary effect and the grain boundary conduction parameters are calculated. The polyaniline-WO3 nanocomposite with WO3 doping concentration of 15% has exhibited better sensing characteristics towards the target VOC (Volatile Organic Compound) 3-Carene, a breath-based biomarker for malaria. The memristor sensor model of the polyaniline nanocomposite with 15% of WO3 is simulated using MATLAB-Simulink. The pinched hysteresis loop obtained confirmed the memristor properties of the material. 2022, Universiti Malaysia Perlis. All rights reserved. -
Study of transient nature of classical Be stars using multi-epoch optical spectroscopy
Variability is a commonly observed property of classical Be stars (CBe) stars. In extreme cases, complete disappearance of the H? emission line occurs, indicating a disc-less state in CBe stars. The disc-loss and reappearing phases can be identified by studying the H? line profiles of CBe stars on a regular basis. In this paper, we present the study of a set of selected nine bright CBe stars, in the wavelength range of 62006700 to better understand their disc transient nature through continuous monitoring of their H? line profile variations for five consecutive years (20152019). Based on our observations, we suggest that four of the program stars (HD 4180, HD 142926, HD 164447 and HD 171780) are possibly undergoing disc-loss episodes, whereas one other star (HD 23302) might be passing through disc formation phase. The remaining four stars (HD 237056, HD 33357, HD 38708 and HD 60855) have shown signs of hosting a stable disc in recent epochs. Through visual inspection of the overall variation observed in the H? EW for these stars, we classified them into groups of growing, stable and dissipating discs, respectively. Moreover, our comparative analysis using the BeSS database points out that the star HD 60855 has passed through a disc-less episode in 2008, with its disc formation happening probably over a timescale of only two months, between January and March 2008. 2022, Indian Academy of Sciences. -
Study of Three-Dimensional Mapping of Interstellar Extinction in Milky Way Galaxy
The Ultraviolet Imaging Telescope (UVIT) is scheduled to be launched as a part of the ASTROSAT satellite. As part of the mission planning for the instrument we have studied the efficacy of UVIT observations for interstellar extinction measurements. We find that in the best case scenario, the UVIT can measure the reddening to an accuracy of about 0.02 magnitudes, which combined with the derived distances to the stars, will enable us to model the three-dimensional distribution of extinction in our Galaxy. The knowledge of the distribution of the ISM will then be used to study distant objects, affected by it. This work points the way to further refining the UVIT mission plan to best satisfy different science studies. newlineWe report here on our plans to use data from the Ultraviolet Imaging Telescope (UVIT) aboard the ASTROSAT mission to probe the extinction across the entire sky. This mission has been in develonment since 2000 (Agrawal 2001) and is expected to be launched on a Polar Satellite Launch Vehicle (PSLV) rocket by the Indian Space Research Organization (ISRO) in 2013. The UVIT instrument is being developed at the Indian Institute of Astrophysics (IIA) and includes three telescopes, two in the ultraviolet (FUV and NUV) and one in the visible, each including a filter wheel with a number of different filters (Kumar et al. 2012). We have run a series of simulations to determine which filters are best suited for our purpose and will use these results in planning our observations with the UVIT. -
Study of three-dimensional mapping of interstellar extinction in milky way galaxy
It is very difficult to model the three-dimensional distribution of interstellar matter (ISM) in our Galaxy because of the general lack of distance information. One of the few ways to probe the distance of the interstellar gas and dust is through absorption line measurements (in the case of gas) or through extinction (in the case of the dust), but these have been limited to a relatively small number of directions. -
Study of the structural, optical, electrical and electrochemical properties of copper oxide thin films synthesized by spray pyrolysis
In our present study we focus on characterizing copper oxide (CuO) thin films synthesized at various substrate temperatures and to assess the electrochemical performance of the optimized sample. The spray pyrolysis method was used to fabricate CuO thin film samples, with the substrate temperatures ranging from 250 to 400C. The coatings underwent characterization through different analytical techniques, including X-ray diffraction, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, field emission scanning electron microscopy, Raman spectroscopy, and Hall effect measurements. All the thin film samples were confirmed to have a monoclinic phase. The presence of Cu=O was confirmed by Raman spectroscopy. All the samples exhibited P type conductivity except the one synthesized at 400C. Galvanostatic chargedischarge studies revealed a pseudocapacitive nature for the optimized sample synthesized at 350C. The symmetrical charging and discharging curves imply excellent material reversibility, indicating long-term cyclic stability. The Nyquist plot exhibited a semicircle at high frequencies, representing the materials intrinsic resistance and a linear behavior at low frequencies, depicting the ion transfer resistance. The electrode demonstrated favorable electrochemical properties and potential use of the material in supercapacitor applications. 2024, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature. -
Study of the personal factors influencing voluntary turnover amongst women
In a country where the economic and social independence of a woman is dependent on the way households are structured and organised, the rise in their education and decline in their workforce participation rate is an indication of their paradoxical situation. In this study we evaluate the direct effect of the factors in the personal domain of women on her career break decision. The data from 402 Indian women was analysed using Exploratory Factor Analysis and Confirmatory Factor Analysis, which was then followed by Structural Equation Modelling to check the conceptual model developed through literature review. In present study support personal predictors to turnover intention outcome model, confirming the influence of role conflict, role expectation, role perception, stress, financial soundness, role overload and guilt. Role perception and expectation of women were most significant factors influencing turnover intention of women, implying that the most important change needed is for a change in their own mindset and those around them to arrest their exit from the workforce. 2021 Ecological Society of India. All rights reserved. -
Study of the diffuse ultraviolet background radiation at high galactic latitudes
The diffuse background radiation is observed throughout the whole sky and across every wavelength of the electromagnetic spectrum. The study of this background is of great importance as it contains photons coming from a va- riety of astrophysical environments, traveling over the time scales of a few hundred light years to the age of the universe itself. After the discovery of the cosmic microwave background, the diffuse sky in all the other wave- lengths was studied with great interest as they could provide useful insights into the formation history of the universe. In the work outlined in this the- sis, I will be describing this diffuse background radiation observed in the ultraviolet (UV) region. Over more than three decades of observations of the diffuse sky in the UV has revealed our lack of understanding of all the components that con- tribute to the observed background sky in this wavelength region. Initial studies arrived at controversial conclusions with one group suggesting that most of the observed diffuse surface brightness is due to the dust scat- tered starlight while another group suggested contribution from an exotic component along with the dust scattered component. We will explore this background sky in detail by trying to identify individual components and quantify its contribution at various regions in the sky. We have started our analysis at the Galactic pole regions with |b| > 80 using the data from Galaxy Evolution Explorer (GALEX) in the ultravio- let band. A major Galactic component of the diffuse sky in the UV is the starlight scattered by interstellar dust (also called Diffuse Galactic Light: DGL). We chose to study the Galactic poles due to the low dust environ- ment in these regions and easier modeling of the DGL component. We found consistent offsets in the UV data at a level of 230 290 photons s?1 cm?2 sr?1 1 (hereafter photon units) in the far-UV (FUV: 1539 and 480 580 photon units in the near-UV (NUV: 2316 when the UV surface brightness was compared with Galactic tracers like E(B-V) and the infrared surface brightness. These offsets represent the UV brightness at zero column densities. Part of this offset comes from the extragalactic background light (EBL) originating in background galaxies, Quasi-Stellar Objects (QSOs), etc. After careful estimation of this EBL component, we found a residual UV surface brightness of about 120 180 photon units in the FUV and 300 400 photon units in the NUV. The DGL component came to be about 120 photon units in these regions. We also found evidence for contribution from molecular hydrogen fluorescence at a column density of log NH > 20.2 (NH is in cm?2). We conclude that this contribution from H2 is from the cirrus features present at high Galactic latitudes. We further confirmed our findings at the north and south Galactic poles by studying the region between latitudes 70< b < 80 where we found similar offsets and the fluorescence contribution from H2 at the same levels as in the NGP. We proposed a possible contribution to the observed residual surface brightness coming from Hawking evaporation of Primordial Black Holes. But the level of this radiation was not sufficient to account for the entirety of the observed excess. The failure of this explanation only further deepens the mystery of the source of the excess surface brightness of the UV sky. -
Study of the diffuse ultraviolet background radiation at high galactic latitudes
The diffuse background radiation is observed throughout the whole sky and across every wavelength of the electromagnetic spectrum. The study of this background is of great importance as it contains photons coming from a variety of astrophysical environments, traveling over the time scales of a few hundred light years to the age of the universe itself. After the discover of the cosmic microwave background, the diffuse sky in all the other wavelengths was studied with great interest as the could provide useful insights into the formation history of the universe. -
Study of the Balmer Decrements for Galactic Classical Be Stars Using the Himalayan Chandra Telescope of India
In a recent study, Banerjee et al. (2021) produced an atlas of all major emission lines found in a large sample of 115 Galactic field Be stars using the 2-m Himalayan Chandra Telescope (HCT) facility located at Ladakh, India. This paper presents our further exploration of these stars to estimate the electron density in their discs. Our study using Balmer decrement values indicate that their discs are generally optically thick in nature with electron density (ne) in their circumstellar envelopes (CEs) being in excess of 1013 cm-3 for around 65% of the stars. For another 19% stars, the average ne in their discs probably range between 1012 cm-3 and 1013 cm-3. We noticed that the nature of the H? and H? line profiles might not influence the observed Balmer decrement values (i.e. D34 and D54) of the sample of stars. Interestingly, we also found that around 50% of the Be stars displaying D34 greater than 2.7 are of earlier spectral types, i.e. within B0B3. 2024 Societe Royale des Sciences de Liege. All rights reserved.