013003   Kalyana Raman S B;Paramajothi R;Arulmozhi K T (Physics Dep, Annamalai University, Annamalainagar-608 002) : Acoustic studies on molecular interactions of 1-pentanol with some secondary amines. Acta Cienc Indica-Phys 2007, 33(4), 557-62.

Ultrasonic velocities and acoustic parameters for the binary systems of 1-pentanol with some secondary amines are determined at 303K. The excess properties of the acoustic parameters are calculated and used to discuss the nature and strength of molecular interactions present in these systems.

6 illus, 1 table, 9 ref

013002   Kalyana Raman S B;Jayakumari T;Arulmozhi K T (Physics Wing (DDE), Annamalai University, Annamalainagar-608 002) : Steric hindrance to H-bonding in the binary systems of some aliphatic ketones with 1-pentanol. Acta Cienc Indica-Phys 2007, 33(4), 489-95.

Acoustical parameters of the binary liquid systems of methyl isopropyl ketone (MIPK), diethyl ketone (DEK), methyl ethyl ketone (MEK) and dimethyl ketone (DMK) with 1-pentanol are calculated from the experimentally determined values of ultrasonic velocities, densities and viscosities at 303 K. The excess properties of adiabatic compressibility (β^E), free length (L_f, free volume (V_f), internal pressure (π_i), etc. are evaluated and used to discuss the nature and strength of molecular interactions present in these systems.

5 illus, 5 tables, 11 ref

013001   Kalubarme R S;Shinde K P;Pawar S H (Physics Dep, School of Energy Studies, Shivaji Univ, Kolhapur-416 004, Email: shpawar.phy@unishivaji.ac.in) : Electrochemical synthesis of MnAs thin films for near room temperature magnetic refrigeration. Indian J Cryogenics 2006, 31(1-4), 119-22.

Attempts have been made to synthesize room temperature magnetic refrigeration material like MnAs having large MCE in the thin film form by a novel ecofriendly electrochemical route. Electrochemical bath having 0.1 N (CH₃COO)₂ Mn and AsCl₃ were used for the deposition of the MnAs film on stainless steel (SS) substrates. These films were further heat treated at 225°C in 10^-2 torr pressure. XRD studies confirmed that the MnAs thin films were synthesized with the impurity phase of Mn₂As. A SEM study reveals the well covered growth of MnAs thin film.

7 illus, 14 ref

013000   Jha Y K;Chakrabarti S K;Jha I S (Physics Dep, Tribhuvan University, M.M.A.M. Campus, Nepal) : Thermodynamics of NaPb liquid alloy. Acta Cienc Indica-Phys 2007, 33(4), 469-74.

Flory's model has been applied to understand the alloying behaviour of NaPb liquid alloy. The concentration dependence of the free energy of mixing, activity, heat of mixing and entropy of mixing are computed. The temperature dependence of interchange energy has been introduced to compute the heat of mixing and entropy of mixing. The results indicate that the size effect in NaPb alloys may not be important factor for shaping the entropy of mixing as for other thermodynamic calculations.

4 illus, 15 ref

012999   Inbakumar S;Anukaliani A (P.G. and Research Dep of Physics, Kongunadu Arts and Science Collge, Coimbatore-641 029) : Crystalline and surface analysis of glow discharge in plasma treated polyethyleneterephthalate. Acta Cienc Indica-Phys 2007, 33(4), 461-8.

Polyester fabrics are exposed to glow discharge plasma and the physical and chemical properties of the fabrics were studied. Surface analysis was studied using scanning electron microscope. The crystallinity of the fabric was studied from an XRD spectrum and it is seen that the crystallinity of PET is increased. Vertical dragging and droplet tests are taken for the analysis of hydrophilicity behavior of the fabric.

6 illus, 1table, 13 ref

012998   Desai S;Desai K P;Naik H B (Mechanical Engineering Dep, C. K. Pithwala College of Engg. & Tech., Surat) : Effect of valve opening on the performance. Indian J Cryogenics 2006, 31(1-4), 112-15.

Study of effect of valve opening on the performance of orifice pulse tube refrigerator was carried out. The performance of orifice pulse tube refrigerator was evaluated for the frequency range of 2Hz to 6Hz. An effect of orifice opening on no-load temperature at the cold end was evaluated. The lowest cold end no load temperature was recorded as 74.5K at 3 Hz frequency. It was observed that with the increase in orifice opening, the no load temperature at the cold end decreases and passes through a minimum value.

7 illus, 1 table, 13 ref

012997   Desai H B;Poria K C (Physics Dep, Veer Narmad South Gujarat University, Surat) : Effect of etchant compositions on surface of single crystal of bismuth with 2-chloro propionic acid. Acta Cienc Indica-Phys 2007, 33(4), 485-7.

Bismuth metal of 5N purity was used in the growth of single crystals by the horizontal zone-refining method. The (111) cleavage faces of Bi single crystals were etched in different compositions of etchant. Triangular etch pits were observed at sites of dislocation. The activation energies for the lateral motion of edges were calculated using the Arrhanius law, W = exp(^-E/KT) where W is the width of the etch pit T is the absolute temperature. Graph of log W Vs. I/T is used to get activation energy. It is observed that the variation in activation energy is non-linear with the compositions of etchant used.

1 illus, 1 table, 6 ref

012996   Bhattacharya S;Pal S;Taran S;Chaudhuri B K (Solid State Physics Dep, Indian Association for the Cultivation of Science, Kolkata-700 032, Email: sspbkc@rediffmail.com) : Effect of monovalent alkali metal (i.e. Li, Na, K) doping at the R site of RMnO₃ manganite compounds. Indian J Cryogenics 2006, 31(1-4), 37-70.

Recent investigations done on the monovalent alkali metal (Li, K, Na etc.) doped rare-earth manganites RMnO₃ (R= rare earth) have been reviewed. Substitution of R site cation by a small amount of monovalent alkali metal ion produces large changes in the Mn³⁺/Mn⁴⁺ ratio. The radius of R site also changes with doping. These two phenomena mainly affect the structural, magnetic and transport properties in these manganite materials. Magnetic properties show that almost all the samples undergo ferromagnetic to paramagnetic phase transition with the lowering of temperature. The Curie temperature is close (to room temperature for the Na and K doped samples while it is low for the Li doped manganites In this review, importance has been given on the temperature dependent transport properties of different monovalent alkali metal ion doped systems.

33 illus, 5 tables, 79 ref

012995   Anand Kumar (Physics Dep, T.P. College, Madhepura, Bihar) : Analysis of electron affinity difference in CdS/CdTe solar cells. Acta Cienc Indica-Phys 2007, 33(4), 547-51.

Analysis of electron affinity difference in CdS/CdTe solar cells. Recently growing interests have been shown by researchers to go insight these solar cells in view of their importance. The electron affinity difference ΔE_c in CdS/CdTe solar cells fabricated by four different processes has been measured from observations of the variations of open voltages with temperature. It has been concluded that for CdS/CdTe cells, the electron affinity difference is not dependent on the process of cell fabrication. It may be reduced only by changing material, the quantity (A_i/A₁) is technology dependent and can be reduced by an improved process of cell fabrication. The method used for measuring ΔE_c is very simple and may be extended for the estimation of the saturation current I_o.

2 illus, 1 table, 18 ref

012994   Agarwal S;Bhatnagar D (Microwave Lab, Physics Dep, University of Rajasthan, Jaipur-302 004) : Dielectric relaxation study of mixtures of edible saturated fat and hydrogenated fats using microwaves. Proc Natn Acad Sci India-Sect A 2007, 77(Pt 1), 65-9.

Dielectric constant and dielectric relaxation studies of a mixture of saturated and hydrogenated fats in different proportions by volume are carried out at different frequencies and different temperatures. With the help of measured data, scales to check purity of saturated fats samples are prepared.

4 tables, 11 ref

010964   Yadav M P;Santosh Kumar (Phys Dep, Govt. Tilak PG Coll, Katni-483 501, Email: mp_yadav2005@yahoo.com) : Cosmic ray decreases and geomagnetic storms during. Indian J Phys 2007, 81(4), 425-35.

Ninety Cosmic ray intensity decreases (4%) and geomagnetic storms with criteria such that planetary index Ap<62> 30, disturbance storm time index, Dst ≤ - 40nT have been investigated using neutron monitor data and solar geophysical data during the period 1975-1944. It has been observed that the majority of the i.e. 91% geomagnetic storms (GMS's) are associated with coronal mass ejection (CME's). The ejecta is intercepted only when the solar events, originates within 40° of the Sun's central meridian. Further, it is not necessary that maximum number of GMS's should occur during the maximum activity period only. It is also observed that during 66% events the decrease in the cosmic ray intensity started a few hours later than the occurrence of GMS's at the Earth. Further, statistically, it is observed that the sunspot numbers (SSN's) and solar flux are highly correlated during 21st and 22nd sunspot cycles. The GMS's are better correlated with sunspot numbers during the even solar cycle as compared to odd solar cycle. It is found that CME's transit time from the Sun to the Earth space lies between 1 and 5 days.

4 illus, 3 tables, 38 ref

010963   Venugopal C;Kurian M J;Premnadh V K;Renuka G (School of Pure & Applied Physics, Mahatma Gandhi Univ, Priyadarshini Hills, Kottayam-686 560, Email: cvgmgphys@yahoo.co.in) : Stability of the lower hybrid drift wave in a multi-ion plasma. Indian J Phys 2007, 81(4), 445-53.

Investigated the stability of the lower hybrid drift (LHD) wave in a plasma containing hydrogen and positively and negatively charged oxygen ions. In our model, for the length and time scales of the fluctuations the electrons are treated as magnetized, while all the ions are treated as unmagnetized. The Instability is driven by the equilibrium diamagnetic current associated with the hydrogen ions. The growth/ damping rate is modified by a factor dependent directly on the number densities, square of the charges and masses of the oxygen ions. In the presence of the positive oxygen ions, the wave tends to stabilize due to the increased damping by the electrons. On the other hand, the negative oxygen ions tends to aid the instability due to the decreased damping by the electrons.

4 illus, 16 ref

010962   Umaani D E;Prakash S;Natarajan S;Alagar M (NO, Ayya Nadar Janaki Ammal Coll, Sivakasi, Email: alagaranjac@yahoo.co.in) : Infrared spectral studies of DL- methioninium maleate. Asian J Spectrosc 2007, 11(3-4), 173-4.

The FTIR absorption spectra of DL- methioninium maleate was recorded at room temperature. Tentative assignments of the observed wave numbers were made by comparison with the known assignments of wave number of the parent one. Due to the intermolecular hydrogen bonding in the crystal leads to the shift of frequency bands in functional groups. Also the existence of ionized carboxylic group in the anion and the anion in cis form were confirmed.

1 table, 2 ref

010961   Sridhar R;Shukla S K (UHV Section, Centre for Advanced Technology, , Indore, Email: srisri@cat.emet.in) : Design of the vacuum system for the LHC beam dump lines. Bull Indian Vacuum Soc 2007, 10(1), 15-18.

Two beam dumps for the LHC are planned to dump very high energy proton beams circulating in opposite directions in case of beam abort or at the end of a physics run of the machine. The vacuum line will be installed and commissioned in the dump area between the diluter magnets to beam dump. There are two such lines of 632 metres each, one each in underground TD62 and another in TD68 tunnels catering to two opposite beams. The beam dump vacuum system and the vacuum envelope of increasing cross sections is designed for the operational requirements of internal pressure of 10-6 mbar and such that the beam may never interact with the vacuum chamber. The entire line needs to be maintenance free as the residual radioactivity will be very large. The mechanical design of the dump line beam-envelope with the increasing cross sections, interfacing with the diluter magnet at ring end and the window that is placed in front of the absorber blocks of dump, checking interferences with other equipment in the tunnel/ring and finally design of vacuum system were all done at CAT (now RRCAT). In addition, the conceptual layout showing the vacuum chambers and their supports, pumping ports and the proposed instrumentation was also provided to CERN. This paper discusses the technical specifications and the technical report generated on the design of the vacuum system for the LHC beam dump lines in the frame work of the CERN-DAE Collaboration.

3 illus, 20 ref

010960   Sri Ramachandran P;Rajamanickam N (Physics Research Centre, V>H.N.S.N. College, Virudhunagar-626 001, Email: nrmanickam@rediffmail.com) : Franck-condon factors and r-centroids for the band A<. Asian J Spectrosc 2007, 11(3-4), 165-7.

Vibrational transition probabilities namely Franck-Condon factors and r-centroids for the band A¹∑-x¹∑, N¹II - X¹∑ and D¹ II-X¹∑ systems of scandium monochloride (ScCI) molecule have been calculated. The Franck-Condon (FC) factors and r-centroids are very closely related to transition probabilities. which have been evaluated by the more reliable numerical integration using.a suitable potential. In each electronic state, wave functions were computed for all observed vibrational levels by numerical solution of the radial Schrodinger equation in which the potential energy functions was calculated at equally spaced intervals of 0.01 A in the range of nuclear separation range. Values of FC factors and r-centroids are given for all allowed bands of each system and also available band wavelengths are entered in the respective tables.

3 tables, 6 ref

010959   Singh Y P;Singh R A;Das R (Phys Dep, Govt Women's Polytechnic Coll, Sagar-470 001, Email: mail:y_p_s_2k@yahoo.com) : Spectroscopic and intramolecular studies of pharmaceutically important benzoic acid and its amino substitutents. Asian J Spectrosc 2007, 11(3-4), 169-72.

The vibrational absorption spectra of benzoic acid's monomer molecules and its amino substitutents have been studied using GF matrix and AM1 method. Assumilng C₅ point symmetry, vibrational assignments for the observed frequencies have been proposed. The spectra exhibit distinct features originating from low frequency vibrational modes caused by intra-molecular motion. Normal modes have been calculated and an assignment of the observed spectra has been proposed. Experimental frequencies are compared with those obtained by GF Matrix and AM1 method.

1 table, 20 ref

010958   Sarkar A;Ravi Kumar;De U (Physics Dep, Calcutta Univ, 92 A.P.C. Road Kolkata-700 009) : Superconductivity and fluctuation effect in IOXX irradiate Bi-HTSC. Indian J Cryogenics 2005, 30(4), 169-74.

Radiation damage to high temperature superconductors (HTSC) due to high-energy particle beam limits their applications as superconducting magnets and other devices in radiation environments. For a better understanding of such damage, two Bi₂Sr₂Ca₁Cu₂O_8+d or Bi-2212 HTSC systems with different initial states, quenched and slow-cooled, have been irradiated by 55 MeVL₁³⁺ beam under identical conditions. The .. quenched Bi-2212 shows the usual degradation of T_C⁰ (the zero resistance superconducting transition temperature) from the unirradiated value of 80K. However, the slow-cooled Bi-2212 with an unirradiated T_C⁰ of 65K shows an improvement of T_C⁰ on irradiation. Most importantly, a simple analysis of fluctuation induced conductivity or para conductivity reveals that similar type of defects has modified the quenched and slowly cooled samples differently.

1 illus, 1 table, 22 ref

010957   Roy S;Kulshrestha K (Phys and Comp Sci Dep, Dayalbagh Educ Inst, (Deemed University), Dayalbagh, Agra-282 005, Email: sukhevr@hotmail.com) : Controlling light with light in blue-light plant photoreceptor phototropin. Curr Sci 2007, 92(9), 1275-80.

Theoretically analysed all-optical light modulation in the recently discovered LOV2 domain of the blue-light plant photoreceptor phototropin from Avena sativa (oat), based on nonlinear intensity-induced excited-state absorption. Transmission of a cw probe laser beam at 660 nm through LOV2 can be controlled by a cw or pulsed pump laser beam at 442 nm. This modulation is sensitive to the small-signal absorption coefficient, rate constants of L-state and absorption cross-section of the ground state. It is shown that in wild type LOV2 and its mutant LOV2-C39A, the probe beam can be completely switched by the pump laser beam of intensity 50 and 1 kW/cm² respectively. The switching response in LOV2 is faster (-μS) than in other photo-sensitive retinal proteins. Applicability of the characteristics in the design of an optically addressed spatial light modulator and an all-optical switch has been shown.

6 illus, 42 ref

010956   Ravi J;Thomas Lee S;Arenas M;Hernandez R;Nair K P R (Physics Dep, Cochin University of Sci and Technol, Cochin-682 022, Email: jyotsnaravi2004@gmail.com) : Spectral mixture analysis of ground based reflectance spectra using χ<. Asian J Spectrosc 2007, 11(3-4), 151-6.

We have successfully carried out spectral unmixing of reflectance spectra obtained from laboratory measurements done on mixtures of varying proportions of young, matured and dead leaves of a sequoia tree using χ² minimization procedure. The theoretically calculated results for the fraction of various types of leaves in a mixture are found to be in good agreement with the experiment. This method can be extended for spectral mixture analysis of reflectance spectra on a broader scale, for instance, analysis of the reflectance spectra obtained from helicopter measurements, a technique usually employed for mapping forests and hence can help classifying types of vegetation or identifying healthy and infected trees.

2 illus, 4 tables, 8 ref

010955   Raole P M (Pacilitation Centre for Industrial Plasma Technologies, Institute for Plasma Research, Gandhinagar-382 044) : Surface characterization of low pressure plasma modification of materials. Bull Indian Vacuum Soc 2007, 10(1), 3-11.

Surface modification of materials using low pressure plasma techniques such as plasma ion Implantation and plasma sputtering can lead to the surface changes including the composition, bonding, formation of different phases near the surface, surface morphology and topography. These changes are the manifestation of the material character and its behavior during the process, and dependent on plasma parameters as well as the environment in which the processing is done. This is explained by discussing few examples of plasma modification of materials like stainless steels, diamond and other alloys, characterized mainly by X-ray photoelectron spectroscopy (XPS) and Scanning Electron Microscopy (SEM). Austenitic Steel AISI 316 SS samples modified using nitrogen Plasma Source Ion Implantation (PIII) with different energies show nitrides and a small amount of oxides present near the surface apart from presence of expanded austenite or 'S' phase. The enhanced chromium concentration segregated in the narrow depth of about 17.5 nm below the surface is seen in the depth profile, which is mainly in the form of CrN. In another plasma source ion implantation experiment, natural diamond is implanted with nitrogen at 5 KV and studied for the nitrogen state, its bonding with carbon and concentrations at different depths by XPS. It has been observed that C-C Sp³ bonding is converted in to C-C sp² bonding due to partial graphitisation of the surface and there is C-N bond formation. Plasma sputtering is an important step in plasma processes to remove surface contaminants and thin oxide layer before the actual process starts. However, sputtering can lead to the compositional and/or morphological and topographical changes which are beneficial in some applications. SEM study gives the details of such surface modifications.

6 illus, 3 tables, 15 ref

010954   Patil K D;Thool U S;Mohod A N (Mathematics Dep, B.D. College of Engineering, Sewagram, Wardha-442 102, Email: kishordpatil@yahoo.com) : Analysis of the spacetime singularities arising in higher dimension monopole-Vaidya collapse. Indian J Phys 2007, 81(4), 485-93.

Considers the end state of collapsing null radiation together with monopole field in higher dimensional spacetime. The condition for the formation of a naked singularity as a result of the collapse has been obtained. It is found that under certain restriction on the mass function, the collapse leads to a strong curvature naked singularity, violating CCH.

1 table, 38 ref

010953   Nair K P R;Lee T;Ravi J;Lekshmki S;Rajmohan S;Dinish U S;Rasheed T M A (Fisica Dep, Universidad de Conceplion, Casilla-160, Chile, Email: kprnair@gmail.com) : Compact Photothermal deflection setup for determination of thermal diffusivity. Asian J Spectrosc 2007, 11(3-4), 143-9.

A compact, cost effective and sensitive photothermal deflection experimental setup is proposed. The experimental setup is standardized for thermal diffusivity measurements using indium phosphide and silicon wafers and has obtained results which are in perfect agreement with the literature values.

4 illus, 23 ref

010952   Kumar B;Kumar P;Lovleena;Bdikin I K;Chadha G K (Physics and Astrophysics Dep, Delhi Univ, Delhi-110 007) : Compartivte characterization of undoped and Zn-doped Bi₂Sr₂Cacu₂O_8+<100><255> single crystsls grown by self-flux technique. Indian J Cryogenics 2005, 30(4), 175-8.

Undoped and Zn-doped single crystals of Bi₂S₂2CaCu₂0_8+d have been grown by self-flux technique. The effects of Zn-doping on the transition temperature T_C¹ transition width ΔT_C¹, resistivity and structure of Bi-2212 single crystals have been presented. While the transition temperature T_C has changed marginally, a marked change in transition width deltaATC has been observed. The resistivity of the crystals has also increased almost by a factor of ten. The 'a' and 'b' parameters have been found to change by different amounts due to Zn-doping in the crystals. Rocking curve studies revealed that grain misorientation, dislocation density and modulation structure have also been changed as a result of dooing. The analysis of the incommensurate b'-components and modulation wave vector has been made by x-ray diffraction studied for both doped and undoped single crystals, which are represented as q = 0.210b* + c* and q = 0.211b* + c*, respectively.

4 illus, 19 ref

010951   Khan I A;Saeed M;Rafi M (Phys Dep, Univ of Karachi, Karachi, Pakistan, Email: lqbal_khan47@yahoo.com) : An empirical potential function for diatomic molecules. Asian J Spectrosc 2007, 11(3-4), 161-3.

A new analytical potential function for stable diatomic molecules is proposed. Comparative study of the potential curve calculations of our function with those of the Hulburt-Hirschfelder function and the RKR data has been made for 15 molecular states. It is found that the results of our function are as good as that of Hulburt-Hirschfelder. Furthermore, the proposed function predicts fairly accurate values of the parameters α_e and ω_e, χ_e.

1 table, 4 ref

010950   Gunasekaran S;Renuga Devi T S;Sreenivasakumar M;Santhosam K (NO, Spectrophysics Res Lab, Cheenai-600 030) : Analysis on renal failure blood sera - a spectroscopic approach. Asian J Microbiol Biotechnol envir Sci 2007, 9(2), 281-6.

Study was conducted to evaluate the spectral difference between healthy and renal failure blood sera also to find the significance of dialysis in chronic renal failure patients using FTIR spectroscopic technique. To find the spectral difference between healthy and chronic renal failure blood sera, Ten chronic renal failure patients were enrolled in this study and to analyze the significance of hemodialysis in chronic renal failure patients two dialysis patients waiting on a kidney transplant were enrolled. FTIR Spectra of blood sera were recorded over the region 4000-400 cm^-1 on a Perkin Elmer spectrum one FTIR Spectrometer. The internal standard ratio among the absorption peaks were calculated and it is found to be an indicator to differentiate the diseased subjects from the healthy one. The significance of hemodialysis was also analyzed by comparing the internal standard ratios of pre and post dialysed blood sera. It is Statistically observed from the study that the internal standard ratios of specific modes of vibration of urea and creatinine is found to be more significant between healthy and renal failure subjects.

2 illus, 3 tables, 27 ref

010949   Goel S;Bansal V;Rajendra Kumar (PG Studies and Res Phys Dep, J V Jain Coll, Saharanpur) : Damped vibrations of a linearly tapered homogeneous orthotropic circular plate. Indian J Phys 2007, 81(4), 477-84.

The effect of damping on free vibrations of an orthotropic homogeneous elastic circular plate of lineary varying thickness has been analysed in present research work. The governing differential equation of motion has been solved by Frobenius method. The frequencies corresponding to the first two modes of vibrations have been obtained for an orthotropic circular plate with different combinations of boundary conditions for various values of damping constant and taper constant.

3 illus, 19 ref