Sharma R C;Sharma S
000073 Sharma R C;Sharma S (Department of Mathematics, Himachal Pradesh University, Summer Hill, Shimla-171 005) : On couple-stress fluid heated from below in porous medium. Indian J Phys-Pt B 2000, 75(1), 59-61.
A layer of couple-stress fluid heated from below in porous medium is considered. Using linearized stability theory and normal mode analysis, the dispersion relation is obtained. For stationary convection, the couple-stress postpones the onset of convection whereas the medium permeability hastens the onset of convection. The principle of exchange of stabilities is valid for the couple-stress fluid heated from below in porous medium.
Sastry M;Gole A;Banpurkar A G;Limaye A V; Ogale S B
000072 Sastry M;Gole A;Banpurkar A G;Limaye A V; Ogale S B (Materials Chemistry Division, National Chemical Laboratory, Pune-411 008) : Variation in viscous fingering pattern morphology due to surfactant-mediated interfacial recognition events. Curr Sci 2001, 81(2), 191-3.
Study of the formation of finger-like patterns during displacement of a viscous fluid by a less viscous one is of technological importance. The morphology of the viscous-finger patterns generated is a function of many parameters such as the flow rate, difference in viscosities of the two fluids and the interfacial tension. Demonstrates herein that the morphology of patterns formed during viscous fingering in a Hele-Shaw cell during displacement of paraffin oil by aqueous solutions of the surfactant sodium dodecyl sulphate (SDS), is extremely sensitive to interfacial tension variation brought about by complexation of divalent cations with the sufactant SDS. The variation in morphology of the patterns formed has been quantified by measuring the fractal dimensions of structures formed in a radial Hele-Shaw cell as well as the average finger width in a linear Hele-Shaw cell. This technique shows promise for studying other interfacial phenomena in chemistry such as biorecognition as well as dynamic processes occurring at interfaces.
2 illus, 17 ref
Sarma L P;Gowd T N
000071 Sarma L P;Gowd T N (National Geophysical Research Institute, , Hyderabad-500 007) : Raman and Brillouin scatterng studies on liquids and solids using an ultra high resolution spectrometer. Indian J pure appl Phys 2000, 38(5), 335-43.
Use of a state of the art ultra high resolution spectrometer (0.04 cm<^>-1) for both Raman and Brillouin scattering studies on liquids and solids has been reported. Thbmspectrometer calibrated with mercury lines has been standardized by resolving the isotopes of chlorine in the v
21 ref
Ramanjappa T;Bhavani J A;Rajagopal E;Manohara Murthy N
000070 Ramanjappa T;Bhavani J A;Rajagopal E;Manohara Murthy N (Department of Physics, University of Botswana, Gaborone, Botswana) : Excess sound velocity and excess specific acoustic impedance of (2,2,2-trifluoroethan-1-01+benzene), (benzene+dimethyl sulphoxide) and (2,2,2-trifluoroethan-1-01+dimethyl sulphoxide) at 298.15 K. Indian J pure appl Phys 2000, 38(5), 301-5.
Excess sound velocity (U<^>E) and excess specific acoustic impedance (Z<^>E
22 ref
Purohit P P;Pandey V P;Rajput B S
000069 Purohit P P;Pandey V P;Rajput B S (Department of Physics, Kumaun University, Nainital-263 002) : Scattering of monopoles and decay of anti-monopolium. Indian J pure appl Phys 2000, 38(5), 287-95.
Undertaking the study of behaviour of a spin-1/2 monopole moving in the field of mother monopole, Dirac's equation has been solved for energy eigen values and the Hamiltonian of this system has been shown to involve spin contribution. Spin momentum of a monopole has been shown to behave as extra energy source for monopoles interacting with electromagnetic field. Interaction of spin snd orbital moments of a monopole moving in the electromagnetic field has been analysed. S-matrix expansion, scattering amplitude and total Hamiltonian for monopole-anti-monopole scattering has also been undertaken. Study of bound state of a monopole and an anti-monopole has been carried out and it has been shown that this state is very short lived and decays in to two or three photons depending on the spin-statistics of the monopoles involved.
17 ref
Pandey J D;Sharma A K;Pandey A;Soni N K; Murkherjee S
000068 Pandey J D;Sharma A K;Pandey A;Soni N K; Murkherjee S (Department of Chemistry, University of Allahabad, Allahabad-211 002) : Molal volume of multicomponent liquid mixtures of non-electrolytes. Indian J pure appl Phys 2001, 39(4), 222-5.
Inspite of tremendous impressive developments of the molecular theory, an engineer frequently finds the need for physical properties, which have not been measured. The molal volume of a fluid at a given pressure and temperature is an equilibrium thermodynamic property. Wassiljewa equation in conjunction with Hildebrand's relation has been applied to evaluate molal volume of the various classes of liquid mixtures (binary, ternary and quaternary). It has the advantage over the empirical relations since it can be applied to a wide variety of fluids in moderate range. Moreover, it is very simple in form and the parameters have physical significance that is easy to conceive. It was observed after extensive fitting to the Hildebrand relation that V
11 ref
Nicula T
000067 Nicula T (Military Chemistry Application School, , Str. Marasti 48, Campulung-Arges,-0425, Romania) : Particle size distribution measurements using polarized light methods. Indian J Phys-Pt B 2000, 75(1), 53-5.
Attention was paid to particle size distribution (PSD) measurements analyzing the polarization ratio of the light scattered by a polydisperse solution. The sample solutions were prepared mixing latex isotropic spheres of different sizes in order to simulate a variety of size distributions. The scattering computations have been performed to fit the experimental data and thus to determine the sample PSD. Measurements were made using an optical bench-mounted ellipsometer employing a laser diode source as light source.
Navin Chand;Vashishtha S R
000066 Navin Chand;Vashishtha S R (Regional Research laboratory(CSIR), , Habibganj Naka, Hoshangabad Road, Bhopal-462 026) : Melt flow studies of flyash particulate filled PP/PMMA blend. Clay Res 2000, 19(2), 49-56.
New type of filled blend material based on flyash (FA) particulate polypropylene/polymethyl methacrylate (PP/PMMA) blend having flyash loading ranging from 5 to 15 weight per hundred have been developed. Rheological data on filled blends are obtained by using a capillary rheometer at 220°C in shear rate range ranging from 10<^>1-10<^>4 S<^>-1. It has been found that incorporation of flyash into PP/PMMA blend increased the melt viscosity and shear stress. It also reduced recoverable shear strain (S
Midya S K;Maitra S N;Tarafdar G
000065 Midya S K;Maitra S N;Tarafdar G (Department of Physics, Serampore College, Serampore, Hooghly-712 201) : Study of the variation of daily O
Atmospheric ozone even being a very minor constituent, plays a central role to absorb (not all) the solar UV radiations (200 nm to 320 nm) which are lethal to man and other living organisms. The ozone concentration is slowly declining every where throughout the world, but dramatic decrease of O
17 ref
Mangla A;Sil A
000064 Mangla A;Sil A (School of Basic and Applied Sciences, Thapar Institute of Engineering and Technology, Patiala-147 004) : Transport characteristics of 0.3 KC1 : 0.7 ZrO
Composite solid electrolyte having composition 0.3 KC1 : 0.7 ZrO
11 ref
Lataifeh M S
000063 Lataifeh M S (Department of Physics, Mu'tah University, Mu'tah, Al-Karak, Jordan) : Magnetic and mossbauer spectroscopic study of some rare earth-iron intermetallic compounds. Indian J pure appl Phys 2000, 38(5), 331-4.
Magnetization measurements of the rare earth iron intermetallic compounds YFe
Khetrapal C L
000062 Khetrapal C L (NO, University of Allahabad, Allahabad-211 002) : Biomolecular structural studies using NMR. J Indian Chem Soc 2001, 78(3), 112-14.
During recent years, the use of dipolar couplings has gained prominence in biomolecular structural studies particularly with the discovery and use of lyotropic liquid crystalline media with low molecular orders and appropriate solubility properties. Though the idea of using dipolar couplings for such purposes has been there ever since the discovery of the technique of NMR spectroscopy of molecules oriented in liquid crystalline media nearly four decades back, practical difficulties such as the solubility and the spectral complexities in general have been responsible for such a long delay in actually exploiting the idea for biomolecular structural studies. During all these years attempts have been made by several active groups all over the world to overcome the difficulties, to use media with low order parameters and the discovery of new systems with desired solubility and the ordering properties. Such developments are discussed with emphasis on authors contributions and efforts in this emerging area of research.
19 ref
Khah S K;Pourush P K S
000061 Khah S K;Pourush P K S (Department of Instrumentation, Dau Dayal Institute of Vocational Education, Khandari, Agra-282 002) : Eight element circular array of circular patch microstrip antenna in dielectric medium. Indian J Phys-Pt B 2000, 75(1), 63-65.
Theoretical analysis of eight element circular array of circular patch microstrip antenna is proposed for X-band in plasma medium. The far-zone field patterns are obtained using vector wave function approach and analytical technique of microstrip antennas. The field patterns are plotted for both freespace and plasma modes. Other antenna parameters like half power beam width (HPBW), radiation conductance and directive gain are also computed. The results are used for the design of phased array antenna system in mobile communication systems.
Jigeesh N;Radha Krishna Murthy A; Rangacharyulu M
000060 Jigeesh N;Radha Krishna Murthy A; Rangacharyulu M (Physics Department, Nagarjuna University, Nagarjuna Nagar-522 510) : Molecular force field of sulphadimethoxine. Indian J Phys-Pt B 2000, 75(1), 49-51.
Infrared and Raman spectroscopic study of the broad spectrum antibotic sulpha drug sulphadimethoxine have been made. Based on the assignments made to various vibrational frequencies, force constants are evaluated. Force constant studies are needed to have a qualitative study on the properties of molecules. The molecular model, the force constants and G matrices used for the molecule and the method of evaluation of force constants are given. The normal coordinate analysis is attempted on the molecule, treating it as an SO
Islam M N;Alam M K;Zaman M A;Molla N I
000059 Islam M N;Alam M K;Zaman M A;Molla N I (Institute of Nuclear Science and Technology, AERE, GPO Box 3787, Savar, Dhaka, Bangladesh, ) : Application of neutron radiography to building industries. Indian J pure appl Phys 2000, 38(5), 348-54.
Neutron radiography (NR) technique has been adopted to study the characteristics of some Bangladeshi building materials, e.g. bricks, ceramic bricks, heavy concrete, MS rod and shielding materials (borax mixed and boron carbide maixed shields) and some Slovanian building materials, local names of which are Siporex, Malta, Opeka and Beton. Measurements were made to determine defects in all the samples and water absorption behaviour of the Slovanian building materials. Optical density of the neutron radiographs was adopted for measurements in both the cases.
Ishwara Bhat J;Shiva Kumar H R
000058 Ishwara Bhat J;Shiva Kumar H R (Department of Chemistry, Mangalore University, Manalagangothri-574 199) : Acoustic and solvation behaviour of potassium thiocyanate in mixed solvents. Indian J pure appl Phys 2000, 38(5), 306-12.
Measurement of ultrasonic velocity and density at different concentrations of potassium thiocyanate in water, dimethylsulphoxide (DMSO), dimethylformamide (DMF) and their mixtures have been investigated at 298K using ultrasonic interferometer at frequency 2MHz. These data are used to evaluate adiabatic compressibility (βad), intermolecular free length L
11 ref
Gupta S J;Das R
000057 Gupta S J;Das R (Department of Physics, University of Mumbai, Mumbai-400 098) : Vibrational spectra of one-dimensional binary alloys. Indian J pure appl Phys 2001, 39(4), 213-21.
Vibrational frequency spectra of the random one-dimensional binary alloys A
11 ref
Gupta J P;Abrol V
000056 Gupta J P;Abrol V (Environmental Assessment Division, Bhabha Atomic Research Centre, Trombay, Mumbai-400 085) : Theory of purging of multireflection sample cell of an infrared gas analyser. Indian J pure appl Phys 2000, 38(5), 355-8.
Expression has been derived to explain the experimentally observed results of purging of a multireflection sample cell of an infrared gas analyser during its calibration and measurement. This expression can be used to calculate the actual concentration of the specific gas in a limited volume of a gas mixture insufficient to purge completely the sample cell.
Gupta G P;Msezane A Z
000055 Gupta G P;Msezane A Z (Department of Physics, S D (Postgraduate) College, University of Meerut, Muzaffarnagar-251 001) : Energy levels, oscillator strengths and lifetimes in Mg-like sulphur. Indian J Phys-Pt B 2000, 75(1), 23-8.
Energy levels betwen the ground and the various excited states, oscillator strengths and transition probabilities for all dipole-allowed transitions among the 24 LS target states 3s<^>2(<^>1S), 3s3p(<^>1.3p<^>0), 3p<^>2(<^>1S,<^>3P,<^>1D), 3s3d(<^>1.3D), 3s4s(<^>1.3S), 3p3d(<^>1.3p<^>0
20 ref
Gopala Rao R V;Venkatesh R
000054 Gopala Rao R V;Venkatesh R (Department of Chemistry, Banaras Hindu University, Varanasi-221 005) : Estimation of Gruneisen parameter and associated derived quantities. Indian J pure appl Phys 2000, 38(5), 313-18.
Value of Y<^>th, Y'
23 ref
Gohain Barua A;Baruah G D
000053 Gohain Barua A;Baruah G D (Department of Physics, Gauhati University, Guwahati-781 014) : Propagation of dye laser beam through p-benzoquinone-H
Interaction of a tunable dye laser beam with p-benzoquinone-H
Garg M;Shyam Kumar;Quamara J K
000052 Garg M;Shyam Kumar;Quamara J K (Department of Applied Physics, Regional Engineering College, Kurukshetra-136 119) : Thermally stimulated depolarization current behaviour of 50 MeVLi<. Indian J pure appl Phys 2001, 39(4), 259-62.
Different dielectric relaxation processes such as dipolar and space charge have been investigated in high-energy ion-irradiated kapton-H polyimide using thermally stimulated discharge current (TSDC) technique. Kapton-H samples (12.5 μm thickness) are irradiated with Li<^>+ ion (50 MeV0 at different flux (5x10<^>5, 10<^>5, 10<^>4 opms/cm<^>2) at Nuclear Science Center, New Delhi (PELLETRON facility). The thermoelectret of irradiated samples are prepared following the usual method for various poling fields and temperatures. The TSD currents are obtained at heating rate of 2°C/min. The peak appearing at low temperature and associated with dipolar polarization is largely affected in irradiated samples. This is mainly due to the dimerization of the carbonyl groups. The high temperature peak which is associated with space charge relaxation becomes more pronounced in irradiated samples. High-energy ion-irradiation provides deep energy trap centers in the form of conjugated bonds due to de-localized electrons. Low temperature tail of TSDC shows many kinks. These kinks are due to creation of new cross-linking dependent sub polar groups and shallow energy traps as a result of high-energy ion-irradiation.
14 ref
Das R;Sahoo S;Roy K
000051 Das R;Sahoo S;Roy K (Department of Theoretical Physics, Indian Association for the Cultivation of Science, Jadavpur, Calcutta-700 032) : Electron capture in H<. Indian J Phys-Pt B 2000, 75(1), 19-22.
Cross sections for one electron capture in proton-oxygen collisions are calculated by applying two center atomic state expansion method in the energy range of 0.1 to 300 keV. Slater type orbitals are used to represent the ground state wave function of oxygen atom, obtained from the model potential. Comparisons have been made with the existing theoretical findings as well as with the experimental data. The calculated values are found to be encouraging.
14 ref
Bazboruah T;Boruah K;Boruah P K
000050 Bazboruah T;Boruah K;Boruah P K (Department of Electronics Science, Gauhati University, Guwahati-781 014) : Cosmic ray energy spectrum above 10<. Indian J Phys-Pt B 2000, 75(1), 5-10.
Gauhati University mini array of eight plastic scintillator of carpet area 2m<^>2 was operated since September 1996. The array detects giant Extensive Air Shower (EAS) by the method of time spread measurement of secondary particles. All the eight dectors were connected to a data acquisition system capable of recording arrival time spread of secondary particles upto 2.5 μS. Fast electronic circuits were employed to measure the density of shower particles as well as their arrival time spread with a resolution of 10 nS. Reanalyzed the data recorded by the array during September 1996 to April 1999. The reanalysis shows marked improvement in the slope of the energy spectrum above 10<^>17 eV. The best fitted differential energy spectrum observed by the mini array is j(E)=10<^>25.38xE<^>-3.04±06m<^>-2sr<^>-1S <^>-1eV<^>-1.
11 ref
Banerjee P;Bose A;Mathur B S
000049 Banerjee P;Bose A;Mathur B S (Time and Frequency Section, National Physical Laboratory, , New Delhi-110 012) : Semi-empirical model to improve the accuracy of GPS time. Indian J Radio Space Phys 2001, 30(5), 243-8.
New generation of multichannel GPS receivers having a provision of a second pulse output is available. Presents an improved technique to get precise time with the help of such GPS receiver. This technique is based on semi-empirical model utilising the error in instantaneous position co-ordinates from the precise co-ordinates known in advance. The detailed experimental observations show a remarkable improvement in time jitter to about 50 ns from the jitter of 140 ns as observed by the normal technique. This method may also be used for real time applications.
Bandyopathyay K;Bhattacharyya K;Bhattacharya A K
000048 Bandyopathyay K;Bhattacharyya K;Bhattacharya A K (Department of Physics, Burdwan University, Burdwan-713 104) : The maximum entropy principle and Schrodinger eigenvalue problems. Indian J Phys-Pt B 2000, 75(1), 29-35.
Possibility of employing the maximum entropy principle, without any a priori knowledge of moments, to construct approximate density functions for bound, stationary quantum states has been explored. A viable scheme based on the fusion of the prescription provided by the above principle, with modifications as and when necessary, and the Rayleigh-Ritz variational approach has been put forward. Both ground and excited states of several problems in [∞, ∞] are considered. The extension to problems with finite boundaries has also been investigated. Pilot calculations involving various harmonic oscillators, the particle-in-a-box and its supersymmetric partner demonstrate the success of the endeavour beyond any soubt.
22 ref
Awasthi A;Rastogi M;Gupta M;Shukla J P
000047 Awasthi A;Rastogi M;Gupta M;Shukla J P (Department of Physics, University of Lucknow, Lucknow-226 007) : Radio and microwave dielectric properties of PMA and PiBMA in solution. Indian J pure appl Phys 2000, 38(5), 319-23.
Dielectric absorption of dilute solutions of poly (methyl acrylate) (PMA) and poly (isobutyl methacrylate) (PiBMA) in benzene have been studied in the radio and microwave frequency region of 10 to 800 kHz and 10 GHz respectively and at five different temperatures 303, 313, 323, 328 and 333 K. Using frequency variation technique enthalpies of activation for PMA and PiBMA have been found to be 11.4 and 26.1 kJ/mol respectively. For both the systems, data evaluated using frequency variation method were also supported by the measurements carried out using concentration variation method at the microwave frequency. The enthalpies of activation ΔHε observed here were expected to be arising due to the internal rotation involving the ester group-C<^>"O
30 ref
Ashok Kumar
000046 Ashok Kumar (Department of Physics, Tezpur University, Napaam-784 028) : Dependence of dopant ion selectivity on incorporation of proton in doped perovskite oxides. Indian J pure appl Phys 2001, 39(4), 263-6.
Proton conducitivity of doped perovskite metal oxides with ABO
23 ref
Ansari M S;Mir G M
000045 Ansari M S;Mir G M (Regional Engineering College, , Srinagar-190 006) : On eigen values of simple harmonic motion. Indian J Phys-Pt B 2000, 75(1), 57-8.
In order to establish correspondence between Bohr's method of quantization and Schrodinger wave function approach, solved wave equation for simple harmonic oscillator, quartic potential and hydrogen atom with the assumption that the particle is totally confined within the classical limits. For certain values of the energy, the wave functions have maximum divergence at large distance from the classical turning points. Call such energy levels a Anti-eigen values. Anti-eigen values are also reported for harmonic and quatic potentials.
12 ref
Angalkalinin D;SIngh G
000044 Angalkalinin D;SIngh G (Centre for Advanced Technology, , Indore-452 013) : Emittance measurements of microtron beam. Indian J pure appl Phys 2000, 38(5), 296-300.
Transverse beam emittance and twiss parameters of a 21 MeV classical microtron beam have been measured using nondestructive method. The beam profiles were recorded as a function of quardrupole strengths. A Gaussian curve is fitted in to the discrete points obtained from the secondary emission wire monitor. The beam ellipse parameters thus obtained have been used for deciding the beam optics of the transfer line which transports the beam from the microtron to the synchrotron. The results of the emittance measurements are discussed.
Alfaz Uddin M;Islam F N;Shahjahan M;Choudhury M G M
000043 Alfaz Uddin M;Islam F N;Shahjahan M;Choudhury M G M (Department of Physics, Rajashahi University, Rajshahi-6205, Bangladesh) : Semi-empirical formulae for electron impact ionization cross-sections. Indian J pure appl Phys 2001, 39(4), 205-12.
Semi-empirical formulae and BEB models are used to calculate the total cross-sections of single ionization of neutral atoms Mg, Al, Si, P, S by electron impact. The parameters of the semiempirical formulae are obtained by fitting the experimental data on the total cross-section of single ionization of the atoms by electron impact over the range of energy varying from the threshold to 200 eV. It is found that the semi-empirical models give qualititively as well as quantitatively good fits, while BEB model gives qualitative fits to the reference set of experimental data.
19 ref
Acharya M;Dash G C;Singh L P
000042 Acharya M;Dash G C;Singh L P (Department of Physics, College of Basic Science and Humanities, O.U.A.T, Bhubaneswar-751 003) : Hall effect with simultaneous thermal and mass diffusion on unsteady hydromagnetic flow near an accelerated vertical plate. Indian J Phys-Pt B 2000, 75(1), 37-47.
Effect of Hall current with simultaneous thermal and mass diffusion on unsteady laminar hydromagnetic viscous incompressible and electrically conducting fluid past a uniformly accelerated vertical porous plate (electrically non conducting) embedded in a uniform transverse magnetic field with heat source is investigated on the assumption of small magnetic Reynolds number. The results are discussed with respect to hydro magnetic parameter (Mt), Hall parameter (m), the buoyancy ratio parameter (N), Suction or injection parameter (a) Schmidt number (Sc) and heat source parameter (S) for Pr=0.71 with respect to air
18 ref
Abd El-Daiem A
000041 Abd El-Daiem A (Physics Department, Faculty of Science(Sohag), South Valley University, Egypt) : Characteristics from Si<. Indian J pure appl Phys 2001, 39(4), 198-204.
Main experimental characteristics (multiplicity correlations) of secondary particles, angular distributions and forward-backward correlations have been investigated from Si<^>28 with emulsion at 4.5 GeV/c per nucleon have been investigated. The mean multiplicity ,n
13 ref
Yadav B C;Shukla R K
000051 Yadav B C;Shukla R K (Opto-Electronic Research Laboratory, Phys Dep, Lucknow University, Lucknow-226 007) : An opto-electronic sensor for monitoring glucose concentration in water. J Optics 2003, 32(1), 13-17.
The proposed sensor is based on monitoring the light scattered by the red particles of cuprous-oxide produced in the chemical reaction of glucose with Benedict's reagent. The experimental set-up is based on the simple scattering phenomenan. Theoretical values are also calculated for a cubical particle of size 1.67 micron.
5 illus, 8 ref
Varadharajan R;Kalyana Sundaram S;Maria Eugenie Pia K
000050 Varadharajan R;Kalyana Sundaram S;Maria Eugenie Pia K (Phys Dep, National College, Trichy) : Internal pressure and free volume from hydration number. J pure appl Ultrasonics 2002, 24(1), 15-7.
The method of determining the isothermal compressibility, ratio of specific heats and hence the internal pressure using hydration number has been described. The internal pressure is compared with thsoe obtained by Suryanarayana's formula.
1 table, 8 ref
Varadharajan R;Kalyana Sundaram S;Maria Eugenie Pia K
000049 Varadharajan R;Kalyana Sundaram S;Maria Eugenie Pia K (Phys Dep, National College, Trichy) : Solvation study of aqueous potassium-acetate using Padova's model. J pure appl Ultrasonics 2002, 24(1), 11-4.
Due to-solvent interaction the compressibility of the solution decreases with the increase in solute concentration. According to Padova's model the compressibility of the solvated part is assumed to be zero and the compressibility of the solution is entirely due to the free solvent part. On the basis of this model, the hydration number, apparent molal compressibility, apparent molal volume and molar solvated volume are calculated. Eventhough the compressibility of the solvated part is zero, the density and viscosity of the solvated part is not equal to zero. Hence a theory to estimate the density and viscosity of the solvated part have been developed and the formula has been applied to aqueous solutions of acetate at different temperatures and verified.
1 table, 7 ref
Sudhanshu S N;Nepal S;Bhattarai G P;Adhikari M P
000048 Sudhanshu S N;Nepal S;Bhattarai G P;Adhikari M P (Phys Dep, Institute of Science & Technology, M M A Campus, Biratnagar, Tribhuvan, Nepal) : Ultrasonic study of molar sound velocity and molar compressibility in binary liquid mixtures of carbontetrachloride with isobutylmethylketone and methylethylketone in the temperature range of 298. 15K to 318.15K. J pure appl Ultrasonics 2002, 24(3-4), 79-86.
The molar sound velocity(R), the molar compressibility (W), free length (Lf), adiabatic compressibility (β), free volume (vf), relative interaction (D) and their excess values have been calculated by experimentally measured values of ultrasonic velocities (U), densities (p) and viscosities (η) of binary liquid mixtures of carbon tetrachloride (CCL4) with isobutylmethylketone (IBMK) and methylethylketone (MEK) in the temperature range of 298.15K to 318.15K. The molar sound velocity (R) and molar compressibility (W) are also found to be very useful tools to predict the nature of interaction. The excess values have been calculated to study the relative molecular interactions between the constituents of the liquid mixtures and the strength of interaction was found stronger in system II (CCl4+MEK) than in system I(CCI4+IBMK)
12 illus, 8 tables, 10 ref
Subrahmanyam Naidu P;Ravindra Prasad K
000047 Subrahmanyam Naidu P;Ravindra Prasad K (Phys Dep, SVUPG Centre, Kavall-524 201) : Ultrasonic study in the binary liquid mixtures of dimethyl sulphoxide. J pure appl Ultrasonics 2002, 24(1), 18-23.
Ultrasonic velocities, densities and viscosities have been measured at temperatures 30, 40 and 50°C over the entire composition range in the binary mixtures of dimethyl sulphoxide (DMSO) with acetonitrile (ACN) and NN dimethyl formamide (DMF). Velocities theoretically evaluated at all concentrations have been compared with the experimental ones. Excess parameters like excess isentropic compressibilities, excess volumes and excess free lengths have been computed and inter molecular interactions have been estimated.
8 illus, 16 ref
Sebastian M D J;Rudraswamy B;Radkhkrishna M C;Ramani
000046 Sebastian M D J;Rudraswamy B;Radkhkrishna M C;Ramani (Physics Dep, Bangalore Univ, Jnanabharathi, Bangalore-560 056) : Mossbauer effect studies and X-ray diffraction analysis of cobalt ferrite prepared in powder form by thermal decomposition method. Bull Mater Sci 2003, 26(5), 509-15.
Cobalt ferrite (CoxFe3-xO4 is prepared in powder form by thermal decomposition of iron and cobalt salts and is analysed by X-ray diffraction and Mossbauer spectroscopic techniques. The variation of Mossbauer parameters, lattice parameters and crystallite size of the products formed with variation in the composition of Fe and Co ratios are studied. The studies confirm the formation of nano-size cobalt ferrite particles with defect structure and it is found to be maximum for the Fe : Co = 60 : 40 ratio of the initial precursor oxides.
6 illus, 6 tables, 11 ref
Saxena M;Bhatnagar P K
000045 Saxena M;Bhatnagar P K (Sci and Humanities Dep, Moradabad Inst of Technol, Moradabad-244 001) : Crystallization study of Te-Bi-Se glasses. Bull Mater Sci 2003, 26(5), 547-51.
Crystallization studies are carried out under non-isothermal conditions with samples heated at several uniform rates. The dependence of the glass transition temperature (Tg), the crystalline temperature (Tc) and the peak temperature of crystallization (Tp) on the composition and heating rate (β) has been studied. For a memory/switching material, the thermal stability and ease of glass formation are of crucial importance. The glass transition temperature Tg, increase slightly with the variation of Bi content. From the heating rate dependence of Tg, the activation energy for glass transition (Et) has been evaluated. The results are discussed on the basis of Kissinger's approach and are interpreted using the chemically ordered network model (CONM).
5 illus, 1 table, 14 ref
Rao S;Rao N B S;Shirlal K G;Reddy G R
000044 Rao S;Rao N B S;Shirlal K G;Reddy G R (Applied Mechanics and hydraulics Dep, National Institue of Technology, Karnataka, Suathkal-575 025) : Energy dissipation at single row of suspended perforated pipe breakwaters. J Instn Engrs-Pt CI 2003, 84(Aug), 77-81.
A laboratory investigation on a single row of suspended porous pipes was conducted in a two-dimensional regular wave flume to study their hydraulic performance. The wave energy losses at the structure were computed and the effects of depth of submergence, incident wave steepness, water depth, pipe diameter, percentage of perforations, size of perforations and relative wave height on loss coefficient were studied. It was found that as incident wave steepness increases, loss coefficient K1 increases. Water depth has insignificant effect on K1. It is also observed that as percentage of perforations increases, K1 increases. For the range of vaiables studied, as the relative wave eight increases, K1 decreases.
7 illus, 1 table, 7 ref
Rao A D P;Raju S B;Vadera S R;Sharma D R
000043 Rao A D P;Raju S B;Vadera S R;Sharma D R (Nuclear Physics Dep, Andhra Univ, Visakhapatnam-530 003) : Mossbauer studies of Sn<. Bull Mater Sci 2003, 26(5), 505-07.
At room temperture, Mossbauer spectra of Sn4+/Nb5+ substituted Mn-Zn ferrites have been taken to understand the site occupancy of substituted ions. The results indicate that both the substituted ions occupy tetrahedral (A) site only at lower concentration of substitution while at higher concentration they occupy both tetrahedral and octahedral sites. At higher concentration of Nb substitution a doublet has been observed besides sextets. The possibility of canting existence on octahedral sites has been discussed. The observed variation of the hyperfine fields, isomer shift, line widths and B/A peak area ratio with the ferrite composition are interpreted.
1 illus, 4 tables, 7 ref
Rajagopalan S;Sharma S J
000042 Rajagopalan S;Sharma S J (Phys Dep, Nagpur University, Nagpur-440 010) : Acoustical studies in shellac-methanol solution. J pure appl Ultrasonics 2002, 24(3-4), 87-90.
Ultrasonic characterization of natural products has gained momentum recently since ultrasonic technique has proved to be very effective, powerful and reliable. Shellac in methanol is chosen it is observed that the ultrasonic velocity varies non-linearly with concentration of shellac in the solution, indicating formation of a complex between solute and solvent molecules. Such a behaviour is due to the presence of COOH and OH groups in the shellac.
3 illus, 22 ref
Rajagopalan S;Sharma S J
000041 Rajagopalan S;Sharma S J (Physics Dep, , Nagpur-440 010) : Adiabatic compressibility and solvation studies of cellulose acetate in cyclohexanone and in carbon tetrachloride. J pure appl Ultrasonics 2002, 24(1), 1-5.
Ultrasonic propagation studies in polymer solutions give insight into the various properties of polymers. Ultrasonic velocity, adiabatic compressibility and solvation studies are reported in cellulose acetate in cyclohexanone and in carbon tetrachloride at different temperatures. It is observed that the adiabatic compressibility decreases almost linearly with increase in the cellulose acetate concentration in the solution. The number of solvent molecules solvated per polymer repeat unit of the polymer is found to decrease with increase in polymer concentration in both the solvents.
6 illus, 34 ref
Pandit A A;More S S;Dorik R G;Jadhav K M
000040 Pandit A A;More S S;Dorik R G;Jadhav K M (Physics Dep, Dr Babasaheb Ambedkar Marathwada Univ, Aurangabad-431 004) : Structural and magnetic properties of Co1+ySnyFe2-2y-xCrxO4 ferrite system. Bull Mater Sci 2003, 26(5), 517-21.
The samples of the series Co1+ySnyFe2-2y-xCrxO4 ferrites with x = 0.0, 0.1, 0.2, 0.3, 0.4, 0.5 and y = 0,05, were prepared by the usual double sintering ceramic technique. The single-phase spinel structure of the samples was confirmed by using X-ray diffractometry technique. The lattice parameter 'a' with an accuracy of ± 0.002 Angstrom were determined using Bragg peaks of XRD pattern. The lattice parameter 'a' decreases with concentration, x, which is due to the difference in the ionic radii of Cr3+ and Fe3+ ions. The X-ray intensity calculations were carried out in order to determine the possible cation distribution amongst tetrahedral and octahedral sites. The X-ray intensity calculation show Cr3+ ions occupying B site. The saturation magnetization, σs, and magneton number, nB (the saturation magnetization per formula unit), measured at 300 K determined from high field hysteresis loop technique decrease with increase in concentration, x, suggesting a decrease in ferrimagnetic behaviour. Thermal variation of low field a.c. susceptibility measurements from room temperature to about 800 K exhibits almost normal ferrimagnetic behaviour and the Curie temperature, Tc determined from a.c. susceptibility data decreases with increase in x.
5 illus, 4 tables, 19 ref
Neelamegam P;Rajendran A
000039 Neelamegam P;Rajendran A (Res & PG Dep of Applied Phys, Nehru Memorial Coll, Puthanampatti, Tiruchirappalli-621 007) : Linear heating system for measurement of thermoluminescence using 8031/51 microcontroller. Bull Mater Sci 2003, 26(5), 565-8.
A linear heating system is developed using a 8031/51 microcontroller for the measurement of thermoluminescence (TL) in alkali halides and other related compounds. This system also measures the temperature and the amount of light emitted by the sample for TL studies.
8 illus, 4 ref
Narayana C
000038 Narayana C (Chem & Phys of Materials Unit, JNU centre for Advanced Sci Res, Bangalore-560 064) : Brillouin scattering studies on charge-ordered manganites. J Indian Inst Sci 2002, 82(2), 93-103.
Brillouin scattering studies were carried out for the first time on charge-ordered maganites, namely, Nd0.5Ca0.5MnO3 and Pr0.63Can0.37MnO3. Surface and bulk magnetic excitations (magnons) were observed in the Brillouin spectra with the characteristics of ferromagnetic magnons. The frequency and intensity of these magnons in the temperature range 300 to 25 K, covering both charge-ordering and antiferromagnetic transition, follow exactly the temperature dependence of the DC magnetic susceptibility. The study strongly suggests the presence of ferromagnetic inhomogeneities in the charge-ordered as well as antiferromagnetic phases.
10 illus, 21 ref
Murthy S R
000037 Murthy S R (Phys Dep, Osmania Univ, Hyderabad-500 007) : Development of low-power loss Mn-Zn ferrites using microwave sintering method. Bull Mater Sci 2003, 26(5), 499-503.
Microwave sintering (MS) method has been successfully used for densifying Mn-Zn ferrites used for high frequency applications. This method needs only a short time to obtain high density when compared to conventionally sintered (CS) Mn-Zn ferrites. The lowest power loss was also achieved at 100 kHz and 200 mT condition for the microwave sintered samples. Conductor embedded ferrite transformers were constructed using CS and MS samples and output power, efficiency, and surface rise of temperature were measured at sinusoidal voltage of 25 V with frequency, 1 MHz. The efficiency and surface rise of temperature of transformer were found to be high and low, respectively.
6 illus, 2 tables, 18 ref
Muraliji D;Sekar S;Dhanalakshmi A;Ramkumar A R
000036 Muraliji D;Sekar S;Dhanalakshmi A;Ramkumar A R (P G & Research Dep of Phys, National College, Tiruchirapalli-1) : Internal pressure and free volume studies in isomers of cresol. J pure appl Ultrasonics 2002, 24(3-4), 76-8.
Cresol draws its importance as a group of important aromatic organic compounds, which finds extensive use in various fields. It occurs in three isomeric forms. Internal pressure of a solution is a single factor, which varies due to all internal intractions. Free volume is the average volume in which the center of the molecule moves inside the hypothetical cell due to the repulsion of the surrounding molecules. Study of these parameters requires determination of ultrasonic velocity, viscosity and density. Internal pressure and free volume studies in aqueous solutions of all the three isomers of Cresol with various concentrations at 304K have been carried out. Comparative study of the variations in molecular interactions of these isomers has been done on the basis of non-linear variation of their internal pressure and free volume with concentration.
3 illus, 3 tables, 5 ref
Muraliji D;Sekar S;Dhanalakshmi A;Ramkumar A R
000035 Muraliji D;Sekar S;Dhanalakshmi A;Ramkumar A R (P G & Research, Dep of Phys, National College, Tiruchirapalli-1) : Comparative study of ultrasonic and thermodynamic parameters of aqueous solutions of cresols. J pure appl Ultrasonics 2002, 24(3-4), 71-5.
Cresol is one of the most important groups of aromatic organic compounds which occur in three isomeric forms. Variations in ultrasonic velocity, vicosity and density play a significant role in understanding the nature of solute-solvent, intra and intermolecular interactions. Acoustical impedance, adiabatic compressibility, intermolecular free length Rao's constant, Wada's constant, relative association and available volume of aqueous solutions of ortho-, meta- and para-Cresol with various concentrations at 304K have been evaluated by experimentally determining their ultrasonic velocity, density and viscosity. Their acoustical relaxation time, ultrasonic attenuation, Lennard Jones potential and Van der Waal's constant have also been computed. Comparative analysis of the molecular interactions in these solutions of isomers of cresol has been carried out on the basis of variation of these parameters with solute concentration.
6 illus, 4 tables, 7 ref