Pisipati V.G.K.M.,Koneru Lakshmaiah College of Engineering |
Madhavi Latha D.,Koneru Lakshmaiah College of Engineering |
Datta Prasad P.V.,Hindu College |
Padmaja Rani G.,Jawaharlal Nehru Technological University Kakinada
Journal of Molecular Liquids | Year: 2012
The effective geometry parameter, α g = n o/n e is utilized to calculate the order parameter in a number of liquid crystals of different homologous series. The results are compared with those calculated using the standard techniques of molecular polarizability and birefringence. The effective geometry parameter's, α g influence on the deflection of the light by the liquid crystal compounds is also studied. © 2012 Elsevier B.V.
Rani R.,Electroceramics Research Laboratory |
Rani R.,Thapar University |
Juneja J.K.,Hindu College |
Singh S.,GVM Girls College |
And 2 more authors.
Journal of Magnetism and Magnetic Materials | Year: 2013
Magnetoelectric composites of nickel zinc ferrite (NZF) and La substituted lead zirconate titanate (PLZT) having representative formula 0.1Ni 0.8Zn 0.2Fe 2O 4-0.9Pb 1-3x/2La xZr 0.65Ti 0.35O 3 (x=0, 0.01, 0.02 and 0.03) were synthesized by a conventional solid state route. X-ray diffraction analysis was carried out to confirm the coexistence of individual phases. Scanning electron microscope micrographs were taken for microstructural study of the samples. Dielectric properties were studied as a function of temperature and frequency. To study ferroelectric and magnetic ordering in composite samples, P-E and M-H hysteresis loops were recorded respectively. M-H hysteresis loops were taken for electrically poled and unpoled samples to confirm magnetoelectric coupling between the two phases (NZF and PLZT). La substitution results in significant improvement in dielectric, ferroelectric and piezoelectric properties of composite samples. © 2012 Elsevier B.V. All rights reserved.
Latha D.M.,Andhra University |
Pisipati V.G.K.M.,Andhra University |
Prasad P.V.D.,Hindu College
Molecular Crystals and Liquid Crystals | Year: 2010
Different thermodynamic parameters are estimated from volume expansion coefficient, α, for a number of N-(p-n-alkoxy benzylidene)-p-n-alkyl anilines, nO.m compounds in isotropic phase at TIN+5°C. The parameters like intermolecular free length, Lf, and molecular radius, Mr, are also computed from density, sound velocity, and refractive index for these nO.m compounds for which the data are available in the literature. The results are discussed in light of these parameters' variations with temperature in a particular phase in a liquid-crystal molecule and in a homologous series. The nature of molecular free length and molecular radius is analyzed and discussed with respect to the different expressions used for the estimation of these parameters and the reasons for their deviations in values from one method to the other. Copyright © Taylor & Francis Group, LLC.
Subba Rao N.,Andhra University |
Subrahmanyam A.,Hindu College |
Subrahmanyam A.,Malineni Perumallu Educational Society Groups of Engineering College |
Babu Rao G.,Acharya Nagarjuna University
Environmental Earth Sciences | Year: 2013
The functional factors responsible for fluoride (F-)-bearing groundwater used for drinking as well as for cooking in the area of Gummanampadu Sub-basin, Guntur District, Andhra Pradesh, India are discussed. The study area is a part of an Archean Gneissic Complex, consisting of banded-biotite-hornblende-gneisses, over which the Proterozoic Cumbhum quartzites, shales, phyllites, and dolomitic limestones occur. The chemistry of groundwater is dominated by carbonates (HCO3 - and CO3 2-) at a higher pH. This results in a higher total alkalinity over total hardness, causing an excess alkalinity. Sodium ion is dominated among the cations (Ca2+, Mg2+, and K+). The concentration of F- (2.1-3.7 mg/L) is higher than that of desirable national limit (1.2 mg/L) prescribed for drinking purpose. A significant positive correlation exists between F- and pH as well as that between F- and HCO3 - + CO3 2-. This indicates that the alkaline condition is the prime conducive factor for dissolving F--bearing minerals more effectively leading to a higher concentration of F- in the groundwater. Furthermore, a positive chloro-alkaline index reflects the ion exchange, and an oversaturation with respect to CaCO3 indicates the evaporation. In addition, a negative relation between the well depth and F- shows the effect of solubility and/or leaching of salts in different depth levels. These factors regulate the concentration of F- in the groundwater. On the other hand, a positive correlation of F- with SO4 2- as well as with K+ shows the human land use activities (namely, use of chemical fertilizers, disposal of domestic wastes, etc.), which add F- to the groundwater. A significant number of the residents of the study area suffer from the health disorders related to fluorosis, which is a consequence of higher concentration of F- in the drinking water. Thus, this study emphasizes the need for supply of safe drinking water, nutritional diet, rainwater-harvesting structures, and public education to realize "health for all" motto of World Health Organization. © 2012 Springer-Verlag Berlin Heidelberg.
News Article | November 30, 2016
The future scientist went to school with children of the "lowest" castes in what is now known as Bangladesh. He went on to play a crucial role in pioneering the breakthrough of radio technology, and he developed theories of plant biology which were only proven nearly a century later. He refused to take patents out on his own work. He even wrote science-fiction in his native language. Jagadish Chandra Bose, an overlooked scientist whose work allowed giant leaps at the beginning of the 20th century, is honored today, on what would be his 158th birthday, by a Google Doodle. Bose (1858-1937) was born into a well-to-do family, as his father was a deputy magistrate and assistant commissioner in the British colonial government. But the family’s ideas were progressive – and Bose started his education in a school with members of the lower castes. At that time, most students would want to be at an English school – but his father wanted him to learn in his native language first. Bose later recalled that he was inspired by starting his learning in such an environment. “In the vernacular school, to which I was sent, the son of the Muslim attendant of my father sat on my right side, and the son of a fisherman sat on my left. They were my playmates,” he said. “I listened spellbound to their stories of birds, animals and aquatic creatures. Perhaps these stories created in my mind a keen interest in investigating the workings of Nature.” Bose then went to Hindu College, and St. Xavier’s College in Calcutta. Although his sights were first set on a job in the Indian Civil Service, his father pushed him to be a scholar. He went to England to study medicine at the University of London – but dropped out because of ill health. Instead, he focused his attention on degrees in natural sciences at the University of Cambridge and the London University. Bose made a stand against discrimination upon his return to India. He secured a job through a colonial appointment of the viceroy at Presidency College. Undertaking research, he was allotted 100 rupees per month – while Europeans were offered 300 rupees. Bose refused the salary – and worked without any remuneration at all – for three full years. He apparently impressed his peers enough that they provided him with the full salary – with a retroactive lump sum for all his work. Bose made it worth their while. In a spectacular demonstration of the newly-discovered existence of electromagnetic waves in Calcutta in 1895, the scientist made a public demonstration of igniting gunpowder and ringing a bell using the invisible forces. Bose had essentially reduced electromagnetic waves to the level of millimeters – a logical progression of the physicists Heinrich Hertz in Germany, and Oliver Lodge in England. Bose essentially invented the “mercury coherer” that Guglielmo Marconi would use for his 2,000-mile transmission across the Atlantic in 1901, which has long been celebrated as the invention of radio. But Bose had a reflexive opposition to acquiring patents. He also invented a series of commonplace microwave components which are still fundamentally in use – but never sought financial or other credit for them. (Some other contemporaries, like Pierre Curie and Wilhelm Roentgen, were also fundamentally opposed to the concept of patents). Bose also was fascinated with plants. His theory of how sap moves up plants was proposed as a pumping action of cells in the endodermis was later proven correct – and he also demonstrated the electrical stimulus at work in plants. The crescograph, a tool of high magnification sued to detect movement and growth of plants, also went unpatented. In both the physics and botanical realms, Bose has been described several times as being 50 to 60 years ahead of his time.
Singh V.,Moradabad Institute of Technology |
Agarwal S.,Hindu College
Thermal Science | Year: 2014
An analysis is made to study magnetohydrodynamic flow and heat transfer for Maxwell fluid over an exponentially stretching sheet through a porous medium in the presence of non-uniform heat source/sink with variable thermal conductivity. The thermal conductivity is assumed to vary as a linear function of temperature. The governing partial differential equations are transformed into ordinary differential equations using similarity transformations and then solved numerically using implicit finite difference scheme known as Keller-box method. The effect of the governing parameters on the flow field, skin friction coefficient, wall temperature gradient (in prescribed surface temperature case), wall temperature (in prescribed heat flux case) and Nusselt number are computed, analyzed and discussed through graphs and tables. The present results are found to be in excellent agreement with previously published work of El Aziz and Magyari and Keller on various special cases of the problem.
Veer D.,Hindu College |
Baboo M.,Hindu College
Oriental Journal of Chemistry | Year: 2012
Complexes of M(III) & M(II) transition metals with N, N'-ethylene-bis-(2-amino-benzamide) have been prepared and characterized by elemental analyses, molar condcutivity, magnetic susceptibility measurments, thermal studies , IR and electronic spectra. Based on these studies octahedral geometry has been proposed for these complexes.
Lalitha Kumari J.,Hindu College |
Datta Prasad P.V.,Hindu College |
Latha D.M.,Koneru Lakshmaiah College of Engineering |
Pisipati V.G.K.M.,Koneru Lakshmaiah College of Engineering
Phase Transitions | Year: 2012
An optical study of N-(p-n-alkyloxybenzylidene)-p-n-butyloxyanilines, nO.O4 compounds with the alkoxy chain number n=1, 3, 6, 7, and 10 has been carried out by measuring the refractive indices using modified spectrometer and direct measurement of birefringence employing the Newton's rings method. Further, the molecular polarizability anisotropies are evaluated using Lippincott δ-function model, the molecular vibration method, Haller's extrapolation method, and scaling factor method. The molecular polarizabilities α e and α 0 are calculated using Vuk's isotropic and Neugebauer anisotropic local field models. The order parameter S is estimated by employing the molecular polarizability values determined from experimental refractive indices and density data and the polarizability anisotropy values. Further, the order parameter S is also obtained directly from the birefringence data. A comparison has been carried out among the order parameter obtained from different ways and the results are compared with the body of the data available in the literature. Copyright © 2011 Taylor and Francis Group, LLC.
Sharma V.K.,Md University |
Dua R.,Md University |
Sharma D.,Hindu College
Journal of Chemical Thermodynamics | Year: 2014
Densities and speeds of sound data for ternary o-chlorotoluene (i) + tetrahydropyran (j) + N-methylformamide or N,N-dimethylformamide or cyclohexane (k) and their sub-binary o-chlorotoluene or (tetrahydropyran + cyclohexane) mixtures have been measured at temperatures (298.15, 303.15, 308.15) K and 0.1 MPa. The excess molar volumes, VijkE, VE and excess isentropic compressibilities, (κSE)ijk, κSE for ternary and binary mixtures respectively have been determined from the experimental densities, speeds of sound values and fitted to Redlich-Kister equation to calculate ternary and binary adjustable parameters along with standard deviations. The excess properties, VijkE and (κSE)ijk have been tested in terms of (i) Graph; and (ii) Prigogine-Flory-Patterson (PFP) theories. © 2014 Elsevier Ltd. All rights reserved.
Sharma V.K.,M D University |
Dua R.,M D University |
Dimple,Hindu College |
Jangra S.K.,AIJHM College
Fluid Phase Equilibria | Year: 2014
Molar heat capacities, CP123 and CPmix, have been measured for the ternary o-chlorotoluene (1). +. tetrahydropyran (2). +. benzene or toluene or o-xylene (3) and their binaries tetrahydropyran (1). +. benzene or toluene or o-xylene (2) at 298.15, 303.15 and 308.15. K and atmospheric pressure. From the experimental results, excess heat capacities, CPE and CPE123 values were calculated and fitted to Redlich-Kister equation to determine binary and ternary adjustable parameters along with standard deviations. The observed CPE and CPE123 data have been analyzed by utilizing topology of the constituent molecules (Graph theory). The estimated CPE and CPE123 values from Graph theory are in agreement with experimental values. The interaction parameters, χ* and χ12/ for binary mixtures (simulated by Graph theory) have been discussed to obtain information about molecular interactions in mixtures. © 2014 Elsevier B.V.