002232   Dwivedi A K (Physics Dep, R.S.K.D.P.G. College, Jaunpur-222 002) : Magnetohydrodynamic cylindrical shock in non uniform medium. Acta Cienc Indica-Phys 2003, 29(3), 227-30.

Self similar solutions for isothermal expansion headed by M.H.D. cylindrical shock surface in a non uniform medium have been investigated. It has been obtained that the region of flow variables behind the shock surface widens in the presence of magnetic field.

2 tables, 9 ref

002231   Dutta K;Sit S K;Acharyya S (Physics Dep, Raiganj College (University College), P.O. Raiganj, Dist. Uttar Dinajpur-733 134) : Relaxation phenomena of polar non-polar liquid mixtures under low and high frequency electric field. Pramana J Phys 2003, 61(4), 759-72.

Simultaneous calculation of the dipole moment μj and the relaxation time τj of a certain number of non-spherical rigid aliphatic polar liquid molecules (j) in non-polar solvents (i) under 9.8 GHz electric field is possible from real ε"_ij parts of the complex relative permittivity ε^*_ij. The low frequency and infinite frequency permittivities ε_0ij and ε_ooij measured by Purohit et al and Srivastava and Srivastava at 25, 35 and 30°C respectively are used to obtain static μ_s. The ratio of the individual slopes of imaginary σ"_ij parts of high frequency (hf) complex conductivity σ^*_ij with weight fractions w_j at w_j → 0 and the slopes of σ"_ij-σ"_ij curves for different w_js are employed to obtain τ_js. The former method is better in comparison to the existing one as it eliminates polar-polar interaction. The hf μjs in Coulomb metre (Cm) when compared with static and reported μs indicate that μ_ss favour the monomer formations which combine to form dimers in the hf electric field. The comparison among μs shows that a part of the molecule is rotating under X-band electric field [5]. The theoretical μ_theo^s from available bond angles and bond moments of the substituent polar groups attached to the parent molecules differ from the measured μ_js and μs to establish the possible existence of mesomeric, inductive and electromeric effects in polar liquid molecules.

6 illus, 2 tables, 16 ref

002230   Dhaliwal A S (Physics Dep, Sant Longowal Institute of Engineering and Technology, Longwal, Sangrur-148 106) : Bremsstrahlung spectra of metallic target produced by <. Indian J Phys-Pt B 2003, 77(2), 185-8.

External bremsstrahlung (EB) specta excited by ³²P beta particles in thick targets of Al,Cu,Sn and Pb have been studied by using a high efficiency scintillation detector. After making the necessary corrections, the experimental distributions were compared with the theoretical distributions obtained from the modified Elwert factor Bethe-Heitler theory. Tseng and Pratt theory and Elwert corrected (non-relativistic) Bethe-Heitler (EBH) theory. The results of measurements for low Z-elements show an agreement with all theories, within 8 to 10% throughout the studied energy region. For medium Z-elements, the experimental results are in agreement with the Tseng and Pratt and modified Elwet factor (relativistic) Bethe-Heitler theories. However, for high Z-elements, particualarly at high-energy end, the experimental results show a better agreement with the modified Elwert factor (relativistic) Bethe-Heitler theory.

2 illus, 12 ref

002229   Demirkol I;Tel E;Arasoglu A;Ozmen A;Sarer B (Phys Dep, Gazi Univ, Fac of Art and Sci, Teknikokullar-Besevler Ankara, Turkey) : The neutron production cross sections for targets Pb, Bi, Au and neutron multiplicity for nuclear spallation reaction induced by 20 to 1600 MeV protons. Bull pure appl Sci-Sect D 2003, 22(1), 55-63.

Various cross sections of the (p + ^206,207,208 Pb), (p + ^nat Pb), (p +<>^>209 Bi) and (p + ¹⁹⁷ Au) reactions have been calculated at energies between 20 and 1600 MeV, using Cascade- Exciton Model (CEM). The neutron multiplicity have been predicted. The Calculated results have been compared with the experimental data taken from the literature. The accordance of the calculated results with the experimental data have been examined.

17 illus, 22 ref

002228   Das S;Jain A K (Nuclear Physics Div, Bhabha Atomic Research Centre, Mumbai-400 085) : Low energy K<. Pramana J Phys 2003, 61(5), 1015-19.

The data for the total cross-section of K⁺ scattering on various nuclei have been analysed in the Glauber multiple scattering theory. Energy-dependent K⁺ -nucleus optical potential is generated using the forward K⁺ -nucleon scattering amplitude and the nuclear density distribution. Along with this, the calculated total K⁺ -nucleus cross-sections using the effective K⁺ -nucleon cross-section inside the nucleus are also presented.

2 illus, 11 ref

002227   Das B S L;Jha A (Physics Dep, C.M. Science College, Darbhanga-846 004) : Analysis of attenuation, phase rotation and cross-polarisation of electromagnetic waves due to rainfall. Acta Cienc Indica-Phys 2003, 29(2), 211-13.

The problem of attenuation, phase rotation and cross polarisation of electromagnetic plane waves due to tropical rain drops has been theoretically investigated using finite element method. The forward scattering amplitudes are employed to obtain the theoretical results using the rainfall data for a tropical country. The theoretical results obtained are compared with those existing in open literature.

2 tables, 10 ref

002226   Das B;Lyga N (Physics Dep, State University of New York, Potsdam, New York-13676, USA) : Cumulant-like correlation function to study temporal behavior of optical sources. Indian J Phys-Pt B 2003, 77(2)195-9, (NULL).

It statistics, the cumulant of a particular order represents the true moment of that order since, in its definition, the effects of all lower orders moments have been washed out. Expressions for the cumulant-like cross-correlation functions (equivalent to cumulants rather than moments) that were obtained by subtracting the effects of lower order correlation functions in a similar manner, cumulant like auto correlating functions were obtained earlier by our group. It is expected that these expressions will provide clearer cross-correlations of two signals showing soem features that may be hidden in the usual cross-correlation functions. Also have been reported the experimental results of the cumulant like auto correlation functions, which were obtained by using the relations reported earlier from the digitized tiem series of the output from a heavily saturated source of amplified spontaneous emission from Xe-He.

3 illus, 15 ref

002225   Choubey N K;Shrivastava G (Mathematics and Statistics Dep, Govt. Science Auto. College, Jabalpur, M.P.) : Elastic vibration in the elliptic crown of thin plate. Acta Cienc Indica-Math 2003, 29(3), 457-60.

3 ref

002224   Chandrasekharan S (Physics Dep, Duke University, Durham, NC 27708-0305, USA) : Connections between quantum chromodynamics and condensed matter physics. Pramana J Phys 2003, 61(5), 901-10.

Features of QCD can be seen qualitatively in certain condensed matter systems. Recently some of the analyses that originated in condensed matter physics have found applications in QCD. Using examples, it discusses some of the connections between the two fields and shows how progress can be made by exploiting this connection. Some of the challenges that remain in the two fields are quite similar. Argues that recent algorithmic developments call for optimism in both fields.

3 illus, 1 table, 20 ref

002223   Chakraborty S;Santra B C;Chakravarty N (Mathematics Dep, Jadavpur University, Kolkata-700 032) : Anisotropic cosmological models and generalized scalar tensor theory. Pramana J Phys 2003, 61(4), 669-73.

Generalized scalar tensor theory has been considered in the background of anisotropic cosmological models, namely, axially symmetric Bianchi-I, Bianchi-III and Kortowski-Sachs space-time. For bulk viscous fluid, both exponential and power-law solutions have been studied and some assumptions among the physical parameters and solutions have been discussed.

15 ref

002222   Chakrabarti S K;Acharya K;Bose K;Mandal S; Chatterjee A;Mandi N M N;Pal S;Khan R (NO, S. N. Bose National Centre for Basic Sciences, JD-Block, Salt Lake, Kolkata-700 098) : Monitoring of Sudden Ionospheric Distrubence (SID) from Kolkata (India). Indian J Phys-Pt B 2003, 77(2), 173-5.

Results of monitoring of sudden ionospheric distrubances (SID). Data have been reported taken continously for two weeks (20th September 2002-4th October 2002). The effects have been found of solar flares on the VLF signal have been compared with those obtained by GOES Satellite of NASA, have been presented monitoring in X-rays adn excellent agreement.

2 illus, 6 ref

002221   Chakrabarti D;De A K;Harindranath A (Theory Group, Saha Institute of Nuclear Physics, 1/AF Bidhan Nagar, Kolkata-700 064) : Fermions in light front transverse lattice quantum chromodynamics. Pramana J Phys 2003, 61(5), 967-77.

Briefly describes motivations for studying transverse lattice QCD. Presence of constraint equation for fermion field on the light front allows different methods to put fermions on a transverse lattice. Summarizes the numerical investigation of two approaches using forward and backward derivatives and symmetric derivatives.

4 illus, 7 ref

002220   Chakrabarti B K;Dutta O (NO, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata-700 064) : An electrical network model of plant intelligence. Indian J Phys-Pt A 2003, 77(6), 549-51.

A simple electrical network model, having logical gate capacities, is proposed for computations in plant cells. It is compared and contrasted with the animal brain network strucuture and functions.

2 illus, 1 table, 9 ref

002219   Carroll A S et al (NO, Brookhaven National Laboratory, Upton, NY 11973, USA) : PHOBOS at RHIC : some global observations. Pramana J Phys 2003, 61(5), 865-76.

Particle production in Au+Au collisions has been measured in the PHOBOS experiment at RHIC for a range of collision energies for a large span of pseudorapidities, <124>η<124> <60> 5.4. Three empirical observations have emerged from this data set which require theoretical examination. First, there is clear evidence of limiting fragmentation. Namely, particle production in central Au + Au collisions, when expressed as dN/dη' (η' ≅ η -y_beam), becomes energy independent at high energy for a broad region of η' around η' = 0. This energy-independent region grows with energy, allowing only a limited region (if any) of longitudinal boost-invariance. Second, there is a striking similarity between particle production in e⁺ e^- and Au + Au collisions (scaled by the number of participating nucleon pairs). Both the total number of produced particles and the longitudinal distribution of produced particles are approximately the same in e⁺e^- and in scaled Au + Au. This observation was not predicted and has not been explained. Finally, particle production has been found to scale approximately with the number of participating nucleon pairs for (N_part)) <62> 65. This scaling occurs both for the total multiplicity and for high P_r particles (3 <60> P_r <60> 4.5 GeV/c).

11 illus, 24 ref

002218   Carroll A S (Collider-Accelerator Dep, Brookhaven National Laboratory, Upton, NY 11973, USA) : Review of Brookhaven nuclear transparency measurements in (p, 2p) reactions at large Q<. Pramana J Phys 2003, 61(5), 847-58.

Summarizes the results of two experiments to measure the transparency of nuclei in the (p, 2p) quasi-elastic scattering process near 90°C in the pp center-of-mass. The incident momenta went from 6 to 14.4 GeV/c, corresponding to 4.8 <60> Q² <60> 12.7 (GeV/c)². First, it describes the measurements with the newer experiment, E850, which has more complete kinematic definition of quasi-elastic events. E850 covers, which has more complete kinematic definition of quasi-elastic events. E850 covers a larger range of incident momenta, and thus provides more information regarding the nature of the unexpected fall in the transparency above 9 GeV/c. Reviews the techniques used in an earlier experiment, E834, and shows that the two experiments are consistent for the carbon data. Uses the transparencies measured in the five nuclei from Li to Pb to set limits on the rate of expansion for protons involved in quasi-elastic scattering at large momentum transfer.

10 illus, 1 table, 26 ref

002217   Boyo A O;Boyo H O (Phys Dep, Lagos State Univ, Ojo, Lagos State, Nigeria) : Some observations on the electrical properties of iron clay composite resistors. Bull pure appl Sci-Sect D 2003, 22(1), 81-9.

An experimental investigation has been carried out to study variations of the electrical properties (Variation of Resistance with length, firing time, Iron content, Firing Temperature, Normalized sheet resistance and particle grain size effect), occurring in thick film (cement) resistors during annealing process. The results point out that the size effects in thick films resistor are to be viewed as a composition - dependent phenomenon. Experimental results show that the resistors exhibit both inverse and direct size effects. Also the measurements of electrical properties showed that the electrical resistors. The peak firing temperature, firing time and furnace atmosphere was found to have condiderable effect on the resistance of the resistors and the particle size affects the values of resistance as expected.

8 illus, 16 ref

002216   Boyo A O;Boyo H O (Phys Dep, Lagos State Univ, Lagos, Nigeria) : Thermodynamics properties of liquid Cr - Mn alloys. Bull pure appl Sci-Sect D 2003, 22(1), 1-11.

First - order quasichemical theory has been used to explain free energy of mixing, Concentration fluctuations in the long avelength limit Scc (0), the Warren Crowley short-range order parameter, Heat of mixing. Entropy of mixing and Diffusion coefficient. The assumption of a complex of the form CrMn enables us to calculate these parameters and to reproduce the important features of compound formation and phase separation observed experimentally at different composition in the alloy. There is a qualitative agreement between the calculated and the experimental quantities. The Cr - Mn is a weakly ordered system. From difusion coefficient D, it has been observed that with increasing concentration of Mn, there is increase in the tendency for compound formation.

8 illus, 11 ref

002215   Bora K;Choudhury D K (Physics Dep, Gauhati University, Guwahati-781 014) : Transversity of quarks in a nucleon. Pramana J Phys 2003, 61(5), 979-85.

The transversity distribution of quarks in a nucleon is one of the three fundamental distributions, that characterize nucleon's properties in hard scattering processes at leading twist (twist 2). It measures the distribution of quark transverse spin in a nucleon polarized transverse to its (infinite) momentum. It is a chiral-odd twist-two distribution function - gluons do not couple to it. Quarks in a nucleon/hadron are relativistically bound and transversity is a measure of the relativistic nature of bound quarks in a nucleon. Reviews some important aspects of this less familiar distribution function which has not been measured experimentally so far.

33 ref

002214   Bishoyi K C;Rout G C;Behera S N (P G Department of Physics, F M College (Autonomous), Balasore-756 001) : Normal state raman spectum of high-T_c cuprates. Indian J Phys-Pt A 2003, 77(6), 593-8.

Presents a microscopic theory to explain Raman spectra of high-T_c cuprates R_2-xM_xCuO₄ in the normal state. Uses electronic Hamiltonian prescribed by Fulde in presence of anti-ferromagnetism. Phonon interaction to the hybridization between the conduction electrons of the system and the f-electrons has been incorporated in the calculation. The phonon spectral density is calculated by the Green function technique of Zubarev at zero wave vector and finite (room) temperature limit. Parameter dependence of Raman active phonon frequencies are studied by varying model parameters of the system i.e. the position of f-level (E_f), the effective electronphonen coupling strength (g), the staggered mangetic field (h1), and the hybridization parameter (v). The four Raman active peaks (P₁ to P₄) represent the electronic states of the atomic sub-systems of the cuprate systems. They show up as phone excitations due to the coupling of the phonen to the electrons and the anti-ferromagnetic gap.

3 illus, 20 ref

002213   Bindu R G;Lilly T;Laila M;Panicker P G T; Domini I;Mohanan S (Physics Dep, University College, Thiruvananthapuram-695 034, Kerala) : A new relation to estimate adiabatic compressibility of binary mixture at different temperatures and concentrations. Indian J Phys-Pt B 2003, 77(2), 189-93.

Using the definition of adiabatic compressibility, a new relation has been deduced to estimate the adiabatic compressibility of liquid mixtures at different temperatures from the knowledge of temperature coefficients of sound velocity and density of pure components. The validity of the relationship is examined by comparing the calculated values with the experimental values of adiabatic compressibility of three binary liquid mixtures, benzene + toluene, pyridine + water and polymethylmethacrylate + chlorobenzene at different tempretures and the results are explained on the basis of molecular interaction between the components.

3 illus, 1 table, 10 ref

002212   Bhownick K;Mukhopadhyay A (Physics Dep, Jadavpur University, Kolkata-700 032) : Variation of the intermolecular distance with temperature of the mesogen CCH₅. Indian J Phys-Pt A 2003, 77(6), 615-17.

The cyanocyclohexyl cyclohexance CCH₅ (C₁₈H₃₁N) shows the following phase transitions. X-ray diffraction studies have been conducted on the mesogen in the solid and liquid phases. However, the temperature variation of its parameters namely apparent molecular length/layer thickness/and intermolecular spacing D in the liquid mesophase has not been determined to date. In the this work, X-ray photographs of the sample in the liquid phase has been taken at different temperatures and the variation of intermolecular separation with temperature determined. The results have been compared with X-ray data in the solid phase.

2 illus, 9 ref

002211   Bhattacharya R (NO, Krishnath College, Berhampur, Murshidabad-742 101) : Measurement of atmospheric radio noise field strength during severe meteorolgoical distrubances. Indian J Radio Space Phys 2003, 32(3), 154-7.

Atmospheric radio noise field strength in the tropical station Calcutta have been analysed with a special emphasis on its types and forms. Some typical records of its variations during disturbed weather conditions due to monsoon depression and cyclonic storm associated with torrential rainfall are presented.

2 illus, 1 table, 14 ref

002210   Bhalerao R S (Theoretical Physics Dep, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai-400 005) : Collective flow in relativistic heavy-ion collisions. Pramana J Phys 2003, 61(5), 1021-5.

A brief introduction is given to the field of collective flow, currently being investigated experimentally at the Relativistic Heavy-Ion Collider, Brookhaven National Laboratory. It is followed by an outline of the work that the author has been doing in this field, in collaboration with Nicolas Borghini and Jean-Yves Ollitrault.

8 ref

002209   Benjamin C;Jayannavar A M (NO, Institute of Physics, Sachivalaya Marg, Bhubaneswar-751 005) : Fano resonance in presence of dephasing and evanescent mode. Indian J Phys-Pt A 2003, 77(6), 565-9.

Elenalyze the effect of incoherent transport of Fano resonances. In Close proximity to recent experimental results has been found that the treansition from Fano to Lorentzian line-shapes with increasing incoherence. In the presence of evanescent wave propagation in th AB interferometer with a quantum well no Fano line shapes are observed. Only when one arm of the AB interferometer is made propagating do we recover Fano line-shapes.

4 illus, 15 ref

002208   Barghouthi I A;Qatanani N A (Physics Dep, Faculty of Science Al-Quds University, P.O. Box 20002, Jerusalem, Palestine) : Monte carlo simulation of maxwell molecule interaction in space plasma. Indian J Phys-Pt B 2003, 77(2), 241-5.

A Maxwell molecule interactions model by the Monte Carlo method is proposed for space plasma simulations. The model describes a collision between a minor ion with a background neutral. As a result of a Maxwell moelcule collisions, the magnitude of the relative velocity is unchanged but its direction is altered. However, the velocity of the center of gravity remains the same both in magnitude and direction beofre and after the collision. In the simulation, pairs of particles are generated at random, the changes in the velocities due to Maxwell nolecule interactions are calculated.

9 ref

002207   Banerjee S (NO, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai-400 005) : α_s Measurements. Pramana J Phys 2003, 61(5), 803-17.

The strong coupling constant, α_s, has been determined from many pure inclusive and semi-inclusive measurements. All these measurements, measured at different scales, are consistent among each other and the measurements can be combined to give αs(mz) = 0.118±0.003.

5 illus, 4 tables, 17 ref

002206   Bakkialakshmi S;Shanthi B;Deepa S (Physics Dep, Annamalai University, Annamalainagar-608 002) : Study of fluorescence quenching of some aromatic amines by P-chloranil in two different solvents. Acta Cienc Indica-Phys 2003, 29(3), 247-52.

An attempt has been made to obtain the fluorescence quenching spectra of some aromatic amines (Aniline, P-Toluidine, P-Anisidine and P-chloroaniline) using p-chloroanil as a quencher in cyclohexane and benzene. The stern-volmer plots for all the quenching processes are drawn. Stoke's shift, ionization potential, electron affinity and the solvent parameter (z) are calculated.

4 illus, 3 tables, 5 ref

002205   Bains B S (Physics Dep, Punjabi University, Patiala-147 002) : Extraction of magnetic moment from neutron pickup spectroscopic data. Acta Cienc Indica-Phys 2003, 29(1), 73-6.

Magnetic dipole sum rule for neutron pickup reactions has been applied to obtain the ground state magnetic dipole moment of some odd-A nuclei. The spectroscopic factors from pickup reactions have been used as input parameters in the sum rule equation.

2 tables, 16 ref

002204   Arun Murthy T V S;Murthy V R (Physics Dep, S.S.G.M. College of Engineering, Shegaon-444 203) : Diamagnetic susceptibility studies of a few simple molecules. Acta Cienc Indica-Phys 2003, 29(3), 231-4.

The diamagnetic susceptibilities of some simple molecules and some simple systems of the type bent symmetric molecules of XY₂ type; planar XY₃; pyramidal XY₃; XY₄ tetrahedral; XY₃Z type; XY₂Z₂ type; XYZ₃ type are studied by a molecular vibration approach from molecular vibration parameters like force constants and mean amplitude of vibration. The estimated values are discussed in relation to the literature values.

2 tables, 7 ref

002203   Anil Kumar;Singh S;Rakesh Kumar (Physics Dep, Hindu College, Moradabad) : Vector valued wavelet packets for vector valued signal spaces. Acta Cienc Indica-Phys 2003, 29(3), 321-6.

Wavelet transforms and quantization methods provide a tool for analyzing the signal processing. The signal space, in which vector valued signals like video images are described, is called vector valued function space. The relatively new field of vector valued wavelet packets offers more design options and are able to combine several desirable transform features. Presents the techniques of formation of vector valued wavelet packets from low pass and band pass filters with matrix forms, which are called matrix quadrature mirror filters (MQMF,s) and then shows some fundamental characteristics of vector valued wavelet packets. The techniques exhibit performance equal to, or in several cases superior to, current analysis of the processing of vector valued signals.

10 ref

002202   Ananthanarayan B (Centre for Theoretical Studies, Indian Institute of Science, Bangalore-560 012) : Review of chiral perturbation theory. Pramana J Phys 2003, 61(5), 911-20.

A review of chiral perturbation theory and recent developments on the comparison of its predictions with experiment is presented. Some interesting topics with scope for further elaboration are touched upon.

59 ref

002201   Al Share M (Physics Dep, Mutah University, P O Box-7, Mutah-Karak (Jordan)) : Effect of rotation of the methyl group on the rotational constants A, B and C of the CH₃CN molecule. Acta Cienc Indica-Phys 2003, 29(3), 241-6.

The effect of the rotation of the methyl group through a polar angle from 0° to 360° on the rotational constants. A, B and C of the CH₃CN molecule over the range of bending angle, (a + b), from 0° to 50°. The variations in these constants from the v₈, 2v₈ and 3v₈ vibrational states were found to be negligible. Therefore, the three hydrogen atoms of hte methyl group can be considered as a point mass of 3m_H in calculating the moment of inertia tensors I_xx, I_yy and I_zz.

4 illus, 13 ref

002200   Ahmad Z;Jackson (Physics Dep, Faculty of Science, University of Maiduguri, P.M.B. 1069, Borno State, Nigeria) : Study of particle-nucleus collisions at 24, 50 and 400 GeV/c. Acta Cienc Indica-Phys 2003, 29(2), 107-18.

An attempt has been made to investigate multiplicity, dispersion, and pseudorapidity distributions of shower particles produced in 24, 50 and 400 GeV/c hadron-nucleus collisions. The study of pseudorapidity reveals that with the increase in the mass number of the target nucleus, the excess of particles appears in the target fragmentation region, shifting the maxima of the distributions towards smaller values of rapidity. Further, with the increase in the incident energy, the excess of particles appears in the projectile fragmentation region. Finally, on using the additive quark model, the mean normalized multiplicity has been observed to be independent of the energy and nature of the projectile, suggesting a new kind of scaling in hadron-nucleus collisions.

9 illus, 4 tables, 18 ref

002199   Ahmad Z;Husani M A (Physics Dep, Faculty of Science, University of Maiduguri, P.M.B. 1069, Borno State, Nigeria) : Related power-law growth of particle multiplicities near midrapidity in central Au+Au collisions and in p<. Acta Cienc Indica-Phys 2003, 29(2), 189-93.

A simple power-law growth of charged-particle multiplications near midrapidity in central Au+Au collisions at √s_NN = 56 and 130 GeV, recently measured at RHIC, is derived. Gives predictions for the central particle densities upto √s_NN = 1800 GeV. A strong growth of the +Au densities above those for p^-(p) - p collisions is predicted.

15 ref

002198   Ahmad Z (Physics Dep, Faculty of Science, University of Maiduguri, P.M.B. 1069, Borno State, Nigeria) : Some characteristic of particles produced in 3.7A GeV/c<. Acta Cienc Indica-Phys 2003, 29(3), 331-3.

3 illus, 2 ref

002197   Ahmad Z (Physics Dep, Faculty of Science, University of Maiduguri, Borno State, Nigeria) : Cluster production in 14.5A GeV/c Si-nucleus collisions. Acta Cienc Indica-Phys 2003, 29(3), 221-6.

Characteristics of clusters of relativistic charged secondaries produced in 14.5A GeV/c Si-nucleus collision are investigated by examining the behaviour of the rapidity gap distribution. The findings reveal that the maximum number of relativistic charged particles constituting a cluster is four. Further, the size of the cluster is observed to remain essentially independent of the mass of the struck nucleus. A comparison of the result of the study with those reported earlier for hadron-hadron and hadron-nucleus collisions indicates that similar mechanisms may operate in the production of secondary particles in both hadronic and nuclear collisions at high energies.

5 illus, 1 table, 13 ref

002196   Ahmad Z (Physics Dep, Faculty of Science, University of Maiduguri, Borno State, Nigeria) : Multiparticle production in 24, 50 and 400 GeV/c particle-nucleus interactions. Acta Cienc Indica-Phys 2003, 29(2), 131-42.

Some interesting aspects of multiparticle production in 24 and 400 GeV/c p-nucleus and 50 GeV/c π-nucleus collision have been studied. The correlation of fast target protons with evaporated and shower particles produced in these interactions have been thoroughly investigated. The results reveal that the average number of shower particles produced in these interactions is in marked disagreement with the values predicted by the simple independent particle and hydrodynamical models. Finally, on invoking the additive quark model, the mean normalized multiplicities R₄ and R₅ are observed to the independent of the nature of the projectile indicating a new kind of scaling in hadron-nucleus interactions.

11 illus, 2 tables, 20 ref

002195   Ahmad Z (Physics Dep, University of Maiduguri Borno State, Maiduguri, PMB 1069, Nigeria, ) : Maximum charged particle density fluctuations in relativistic heavy-ion collisions. Acta Cienc Indica-Phys 2003, 29(2), 119-30.

Correlation and clusterization amongst relativistic charged particles produced in 4.5A and 14.5A GeV/c 28Si-nucleus collisions are investigated by examining the maximum fluctuations in the density of relativistic charged particles in narrow pseudorapidity-bins. Δ η in the Monte Carlo background. For a fixed Δη, in the maximum charged particle particle, density decreases exponentially with features are, however, observed to the essentially independent of the beam energy and target size. Furthermore, the maximum charged correlation and clustribution in a narrow pseudorapidity of the study with those reported by UA5, NA22 Collaborations and other groups permits us to draw some interesting and useful conclusions.

11 illus, 3 tables, 15 ref

002194   Ahmad Z (Physics Dep, Faculty of Science, University of Maiduguri, Maiduguri, P.M.B. 1069, Borno State, Nigeria) : Characteristics of events accompanied by hadrons in the backward hemisphere in relativistic nucleus-nucleus collisions. Acta Cienc Indica-Phys 2003, 29(1), 89-91.

4 illus, 8 ref

002193   Agarwal Y K;Verma P K (Physics Dep, Aligarh Muslim University, Aligarh-202 002, Uttar Pradesh) : Infrared spectrum of C6-spiro steroidal tetrazine. Indian J Phys-Pt B 2003, 77(2), 215-21.

Chloro, Bromo, lodo and Acetate derivatives of C6 - spiro steroidal tetrazine, have been prepared. Infrared spectra of these derivatives and the parent compound have been recorded in the range 650-4000 cm^-1. Vibrational analysis has been performed in terms of various fundamental vibrations and combinations of these vibrations. These compounds exhibit some interaction vibrations, which indicate the nature of complexities in such big molecules. Assignments of all the observed frequencies are proposed and thermodynamic functions calculated for a few temperatures in the range from 100 to 1500 k.

6 tables, 25 ref

001209   Midwest research Institute (NO, , The State of Missourui, 425, Volker Blvd, Kansas City, Missouri 64110, USA) : Process for preparation of a semiconductor film. 0000, (NULL), (NULL).

001208   Veerabuthiran S;Satyanarayana M (NO, Space Physics Laboratory, Vikram Sarabhai Space Centre, Trivandrum - 695 022) : Characteristics of cirrus clouds observed at low latitude tropical coastal station, Trivandrum using lidar. Indian J Radio Space Phys 2003, 32(5), 278-85.

High altitude cirrus clouds at about 1-2 km below the tropopause were observed using the multiwavelength lidar system located at a tropical station, Trivandrum (8°33'N, 77°E). Seasonal variations of these clouds were studied over a period of one year. The clouds were seen almost 50% of the time of lidar operation. An analysis of lidar data has shown frequent occurrence of such clouds near the tropopause. Based on their optical depth, cirrus clouds were classified into two categories, namely thick cirrus (optical depth <62> 0.03) and thin cirrus (optical depth <60> 0.03) and their occurrence frequencies were about 64% and 36% of the total occurrences.

5 illus, 1 table, 28 ref

001207   Singh G N;Shrivastava P K (Physics Dep, Sudarshan Degree College, Lalgaon, Rewa-486 115) : Pressure effect in cosmic ray count rates of neutron monitors. Ultra Scient phys Sci 2002, 14(2), 206-9.

Cosmic rays in the form of neutron component are being continuously detected on earth surface. A neutron monitor is being used by cosmic ray research workers since last three decades. Cosmic ray counts are mainly effected by atmospheric pressure. These count rates are also influenced by atmospheric pressure. The relation between pressure corrected cosmic ray count rates and pressure uncorrected count rates for the year 1991 has been studied. Analysis indicates anticorrelation between pressure corrected and uncorrected count rates.

4 illus, 5 ref

001206   Shrivastava P K;Shrivastava P (Physics Dep, Govt New Science College, Rewa - 486 001) : Observation of recovery time characteristics in cosmic ray Forbush type. Indian J Radio Space Phys 2003, 32(5), 266-70.

An attempt has been made to select about 33 Forbush type decreases occurring during 1986-1999 at Kiel Neutron Monitor Station. This interval covered the whole period of sunspot solar cycle 22 and ascending part of solar cycle 23. Recovery time characteristics of Forbush decreases are studied. The average recovery time of neutron monitor energies is 4 days, but varies from 2 to 10 days. No significant difference in the average recovery time is observed from two different rigidities. The relative amplitudes of these decreases are examined.

7 illus, 1 table, 10 ref

001205   Sharma P R;Mishra U (Mathematics Dep, University of Rajasthan, Jaipur-302 004) : Unsteady flow through a horizontal channel: flower wall bounded by permeable material and upper being impermeable wall. Ultra Scient phys Sci 2002, 14(1), 59-62.

Unsteady flow of an incompressible viscous fluid through a horizontal channel formed by a permeable lower wall and an impermeable upper wall is investigated. Fluid velocity expression is derived in terms of slip velocity, discussed numerically and shown through graphs. The expression of mass flow per unit width through the channel is derived, discussed numerically and values are presented through tables.

2 illus, 2 tables, 5 ref

001204   Sarang K C;Jose C B (Mathematics Dep, University of Rajasthan, Jaipur) : Liquid flowing down an open inclined porous channel. Ultra Scient phys Sci 2002, 14(2), 172-7.

The problem of steady laminar viscous incompressible fluid down an open porous channel under gravity has been studied. The expression of flux across the cross-section is derived and discussed. It is observed that for a given area of cross-section, the flux is maximum when the depth and width are in the ratio 1:2.

2 illus, 16 ref

001203   Sahoo S K;Giri S S;Sahu A K (Central Institute of Freshwater aquaculture, , Kausalyaganga, Bhubaneswar-751 002) : Cannibalism, a cause of high mortality in Wallago attu (Schneider) larvae. Indian J Fish 2002, 49(2), 173-7.

A study was conducted to find the effect of stocking density on b io-growth, specific growth rate, percent weight gain and survival of Wallago attu larvae during in-door larval rearing. The larvae of average weight 2.64±0.21 mg and length 5.80±0.36 mm were stocked at a density of 2,4,6,8 and 10 nos/l and reared by feeding live zooplankton, for a period of 10 days. The final body weight, specific growth rate and percent body weight gain of larvae was influenced significantly (P<60>0.05) by stocking densities and highest performance was observed in fish stocked at 10 nos/I. The percent survival of larvae decreased significantly with increase of stocking density and the rate of survival was similar among 6nos/I- 10 nos/I groups. The loss of larvae was observed due to cannibalism during rearing. The lowest stocking density resulted in least cannibalism. Systematic approach and some anatomical feature of W. attu larvae are beleived to be helpful for predation during rearing.

2 illus, 1 table, 13 ref

001202   Ram Prakash;Singh A P;Agrawal B M (Physics Dep, Bipin Bihari PG College, Jhansi - 284 001) : Consistency of limiting and bounce averaged diffusion coefficients in pitch angle diffusion and energetic electron precipitation in the inner radiation belt. Indian J Radio Space Phys 2003, 32(5), 271-7.

Limiting and bounce averaged diffusion coefficients are calculated at different L-values in the inner radiation zone. The results show that their calculated values decrease with increasing equatorial pitch angles (α). The values of bounce averaged diffusion coefficient at α ≈ 90° are found to be nearly 2-3 orders of magnitude lower than at α ≈ 90°. The results agree well with the experimental fact that farther the pitch angles from the loss cone, less efficient is the diffusion of electrons into the loss cone and that the energetic electrons having pitch angles from the loss cone, less efficient is the diffusion of electrons into the loss cone and that the energetic electrons having pitch angles closs to 90° are stably trapped in the inner radiation zone.

4 illus, 1 table, 42 ref

001201   Ram Prakash;Agrawal B M;Singh A P (Physics Dep, Bipin Bihari PG College, Jhansi - 284 001) : Incoherent Cerenkov radiation as the source of auroral and polar hiss emissions. Indian J Radio Space Phys 2003, 32(5), 261-5.

For known plasma parameters and observed energetic electron spectra, detailed power calculations are carried out under incoherent Cerenkov radiation mechanism for auroral and polar VLF hiss emissions to confirm their generation mechanism. The results indicate a discrepancy of about an order of magnitude between the calculated and observed peak power intensities. The precipitating electrons having energy of the order of a few tens of electron volt radiating incoherently in Cerenkov mode seem to be the fundamental sources of these emissions, which are further amplified probably by electron cyclotron resonance instability mechanism involving energetic electrons up to the observed power levels during their downward propagation from the source region.

2 illus, 2 tables, 19 ref

001200   Raju N V (NO, City Engineering College, Vasanthapura, Bangalore - 560 061) : Atmospheric aerosols and air pollution. Indian J Radio Space Phys 2003, 32(5), 306-11.

Multiwavelength radiometer measurement of aerosol optical depth (AOD) at ten wavelengths in the visible and near IR is an ongoing programme since 1988 at Mysore (12°N, 76°E), a semi-urban continental area with a population of about 1 million. The analysis of 10-yr data indicates an increase in the spectral AOD which is attributed to the increased air pollution resulting from anthropogenic activities. The pollution related aerosol turbidity parameters α and β are determined graphically from AOD. The size-dependent parameter α shows a decrease initially and later on an increase. The number density parameter β remains almost a constant throguhout the data period. Aerosol size spectrum is retrieved by numerically inverting the AODs, and the aerosol characteristics are estimated. These indicate that α depends on the number of accumulation mode particles, and β on the mass loading.

4 illus, 1 table, 20 ref