014206   Konar S (Department of Physics & Meteorology, Centre for Theoretical Studies, Indian Institute of Technology, Kharagpur 721 302) : The magnetar fields. Bull Astr Soc India 2003, 31(3-4), 363-4.

Discusses the nature of evolution of the magnetic field in magnetars

1 illus, 5 ref

014205   Konar S (Department of Physics & Meteorology, Indian Institute of Technology, Kharagpur 721302) : The binary history and the magnetic field of neutron stars. Bull Astr Soc India 2003, 31(3-4), 187-93.

There has been strong observational evidence suggesting a causal connection between the binary history of neutron stars and the evolution of their magnetic field. One of the plausible mechanisms proposed for the evolution of the surface magnetic field, that of the diamagnetic screening of the field by accreted material has been discussed.

3 illus, 17 ref

014204   Konar C;Saikia D J;Ishwara-Chandra C H; Kulkarni V K (NCRA, TIFR, Pune University Campus, Pune 411 007) : A study of giant radio galaxies. Bull Astr Soc India 2003, 31(3-4), 437-8.

Multi-frequency radio observations have been made of a sample of 17 giant radio galaxies, many of whose structures were not well determined earlier. These sources were observed with the VLA D-and B/C arrays at C and L bands respectively. Two of the sources were also observed with the GMRT at 610 MHz. Presents some of the radio images, and discusses their evolution and consistency with the unified scheme for radio galaxies and quasars.

2 illus, 3 ref

014203   Kharb P;Gabuzda D;Shastri P (NO, Indian Institute of Astrophysics, Bangalore-560 034) : Magnetic field geometry of 3C111 on pc-scales. Bull Astr Soc India 2003, 31(3-4), 433-5.

Multi-epoch Very Long Baseline Polarimetric observations of the Broad Line Radio galaxy 3C111 performed at 8 and 43 GHz after a large millimetre outburst, reveal rapidly evolving parsec-scale radio structure and the corresponding evolution of the magnetic field geometry.

2 illus, 3 ref

014202   Kameswara Rao N (NO, Indian Institute of Astrophysics, Bangalore) : Ultra violet imaging telescope (UVIT)-science. Bull Astr Soc India 2003, 31(3-4), 249-55.

Some of the significant areas of astronomy that would be persued by UVIT, one of the payloads on the proposed Indian multiwavelength astronomy satellite ASTROSAT, is described. Some of the consideraitions and uniqueness of the system are highlighted. UVIT aims to provide flux calibrated images of the sky at a spatial resolution of about a second of arc in the wavelength range 1250 to 3200ÅA along with optical bands.

illus, tables, ref

014201   Joshi Y C;Pandey A K;Narasimha D;Sagar R (State Observatory, , Manora Peak, Naini Tal - 263 129) : Possible microlensing event in the direction of M31. Bull Astr Soc India 2003, 31(3-4), 417-18.

The Cousin R and I band photometric observation of <126>13' X 13' field in the direction of M31 galaxy have been carried out during 1999-2001 to search for microlensing events using pixel technique. Reports a microlensing-like event, of which preliminary analysis indicates that it is a long duration (t_1/2<126> 66 days) event.

1 illus, 5 ref

014200   Joshi B C;Lyne A G;Kramer M (NO, National Centre for Radio Astrophysics (TIFR), Pune 411007) : Next generation software based instruments for pulsar astronomy. Bull Astr Soc India 2003, 31(3-4), 237-42.

High time resolution studies of pulsars require specialized instrumentation to counter the degradation in the quality and time resolution of their radio signals due to dispersion in the inter-stellar medium. The availability of cheap computer hardware in recent years has provided a new alternative to dedicated hardware based solutions used in the past for this purpose. A comparison of old and modern instrumentation to obtain high time resolution data is presented and future trends in pulsar instrumentation are discussed. The salient features of Coherent On-line baseband receiver for astronomy(COBRA), a new digital receiver for pulsar observations at Jodrell Bank Observatory, are listed followed by a brief description of the benchmark code used for designing such systems

1 illus, 13 ref

014199   John A V (NO, Tata Institute of Fundamental Research, Mumbai) : Analysis system for GRAPES-III extensive air shower data. Bull Astr Soc India 2003, 31(3-4), 411-12.

GRAPES-III experiment [Tonwar S.C] consists of 271 scintillators of 1 m². area each and a large area (560 m²) muon detector to record Extensive Air Showers (EAS) produced in the atmosphere by high energy cosmic rays (<128><62>3X10¹³ eV). A comprehensive set of software modules have been developed to analyze this vast amount of data (<128><62>Giga byte/day). A brief description of this is presented.

2 ref

014198   Javaraiah J (NO, Indian Institute of Astrophysics, Bangalore 560034) : `1.3-year' and `153-day' perodicities in the Sun's surface rotation. Bull Astr Soc India 2003, 31(3-4), 317-18.

Using the daily Mt Wilson velocity data during 1986-1994, found that 1.3<145>0.1 yr periodicity is dominant in the Sun's surface `mean' rotation rate (⋅) during 1986-1994 (solar cycle 22). A 153 ± 5 day periodicity found to be substanitially significant in ⋅ during the decay phase of solar cycle 22.

1 illus, 4 ref

014197   Janawelkar S B;Malkar J P;Rao A R;Vadawale S V;Vahia M N;Umapathy C N (NO, Tata Institute of Fundamental Research, Mumbai) : Control and operation of SOXS high energy detector. Bull Astr Soc India 2003, 31(3-4), 483-4.

The control and operation of the SOXS High Energy Detector (HED) experiment is done using a micro-processor based data handling system (the GSAT-2 SOXS High Energy Electronics package - GXHE). The GXHE system is used for onboard data analysis, data compression and satellite interfaces for telemetry, telecommand and on-board power.

3 ref

014196   Jain K;Hasan S S (NO, Indian Institute of Astrophysics, Koramangala, Bangalore 560 034) : Reconstruction of total solar irradiance on multiple time scales. Bull Astr Soc India 2003, 31(3-4), 315-16.

Developed regression models of total solar irradiance on different time scales by parameterizing the combined influence of sunspots and faculae. These models are useful in identifying the key parameters responsible for temporal variations.

1 illus, 3 ref

014195   Indulekha K;Vijayagovindan G V;Ramadurai S (School of Pure and Applied Physics, Mahatma Gandhi University, Kottayam 686 560) : Dissipative collapse of a spherical cluster of gas clouds. Bull Astr Soc India 2003, 31(3-4), 447-50.

Investigates the time scale for the dissipative collapse of a spherical cluster of gas clouds by supplementing for scalar uirial equation with an evolution equation for the energy. Finds that collapse times are more than doubled even for low filling factors f<126>10^-2-10^-3, for which support by supernovae, usually considered for galactic structure formation models is ineffective.

1 illus, 9 ref

014194   Hota A;Saikia D J (Joint Astronomy Programme, Indian Institute of Science, Bangalore 560 012) : Radio study of a superwind-galaxy: NGC1482. Bull Astr Soc India 2003, 31(3-4), 425-6.

Presents GMRT and VLA observations of the superwind galaxy, NGC1482, which has been discovered to have a remparkable hour-glass shaped optical emission line outflow on both sides of the galactic disk. The central region has a prominent compact component, and suggestions of additional compact features.

1 illus, 2 ref

014193   Hoo Lim Sun; Samat A;Othman M R (Sch of Environmental Sci and Natural Resources Fac of Sci and Technol, Universiti Kebangsaan, Malaysia, 43600 Bangi, Malaysia) : Cadmium and lead concentration at residential area nearby labu river system riverbank, Malaysia. Res J Chem Envir 2003, 7(3), 60-3.

A study had been carried to determine the concentration of cadmium (Cd) and lead (Pb) at residential area near Labu River System, in Malaysia and to highlight the potential discharge sources into watercourses. Results obtained showed that Cd (0.022-0.042 mg/l) was classified as Class V while Pb (0.219-0.325mg/l) was categorized in class IV based on Interim National Water Quality Standard (INWQS) of Malaysia with respect to aquatic life, water supply, livestock drinking and irrigation, Concentrations of Cd and Pb also exceed the permissible level for drinking-water quality regulated by World Health Organization (WHO). Results obtained indicate that water bodies of Labu River System were not suitable to be used as potable water supply. Domestic wastewater effluent, household piping systems, infrastructure networks, local scale open burning and agricultural activities were the main sources of Cd and Pb contributor to the Labu River System.

3 illus, 1 tables, 17 ref

014192   Hasan P;Kilambi G C;Baliyan K S (Dep of Astronomy, Osmania University, Hyderabad 500 007) : Near infreared photometry of the young star cluster NGC 2384. Bull Astr Soc India 2003, 31(3-4), 383-6.

The work involves near infrared photometry of the young cluster NGC 2384. Observations were taken at the Mt. Abu Infrared Observatory using the NICMOS3 detector in February 2000. The distance to the cluster is obtained as 2187 pc. The HR diagram for this cluster has been extended to M_J≈5^m and the gaps studied. The age has been determined as 40 Myr. The luminosity function for NGC 2384 is plotted.

2 illus, 10 ref

014191   Goswami A;Kameswara Rao N;Lambert D L (NO, Indian Institute of Astrophysics, Bangalore 560034) : A spectral analysis of HD 165553. Bull Astr Soc India 2003, 31(3-4), 341-2.

High resolution spectra of HD 165553, a star reported to be a spectroscopic binary of spectral type F8 Ib are analysed. The stellar parameters-effective temperature, surface gravity and microturbulence are determined using model atmospheres. A detail chemical composition study indicates a near-solar composition for HD 165553. Comparison of its spectrum with that of γCyg, a normal supergiant of spectral type F8 lab indicates that the star is of a later spectral type; a spectral type G Iab seems more likely for HD 165553.

1 illus

014190   Gopal Krishna; (NO, National Centre for Radio Astrophysics/TIFR, Pune 411007) : Did radio galaxies play a major role in the evolution of the universe. Bull Astr Soc India 2003, 31(3-4), 215-21.

During the 'quasar era', at z<126>2-3, radio galaxies had a much higher comoving density; however, such source are only detectable for small fractions of their active lifetimes, thanks to expansion losses and inverse Compton losses against the much more intense cosmic microwave background. Combining models for the evolution of the size and luminosity of double radio sources with cosmological simulations of the cosmic web of baryonic material, found that during the quasar era a large volume fraction of this web was pervaded by the lobes associated with generations of double radio sources. These overpressured, expanding radio lobes could compress gas clouds in the space engulfed by them and trigger global starburst activity. In the process, radio galaxies could have also seeded the IGM with an average magnetic field <126>10_-8G; moreover, they could have played an important role in the widespread metal pollution of the IGM.

43 ref

014189   Ghosh S K;Kulkarni V K;Ojha D K;Verma R P (NO, Indian Institute of Fundamental Research, Mumbai-400 005) : A multiwavelength study of the galactic star forming region associated with IRAS 20255+3712/S 106. Bull Astr Soc India 2003, 31(3-4), 391-3.

The Galactic star forming region associated with IRAS 20255+3712/S 106 has been mapped simultaneously in 150 and 210 μm bands using the TIFR 1-meter balloon borne far-infrared(FIR) telescope with an angular resolution 1 arc min. The presence of a disk of cold dust is inferred from these FIR maps. High sensitivity and angular resolution radio continuum imaging at 325, 610 and 1280 MHz carried out using the Giant Metrewave Radio Telescope (GMRT), demonstrates the morphological contrast between the emission from the ionized gas and the thermal dust emission. The emission from the carriers of Unidentified Infrared Bands (UIBs) in the mid infrared 6-9 μm as extracted from the Midcourse Satellite Experiment (MSX) survey (at 8, 12, 14 and 21 μm), compares rather well with the radio emission.

2 illus, 4 ref

014188   Ghosh S K;Kulkarni V K;Ojha D K;Verma R P (NO, Tata Institute of Fundamental Research, Mumbai-400 005) : A multiwavelength study of the galactic star forming region associated with IRAS 20255+3712/S106. Bull Astr Soc India 2003, 31(3-4), 391-3.

The Galactic star forming region associated with IRAS 20255+3712/S106 has been mapped simultaneously in 150 and 210μm bands using the TIFR 1-metre balloon borne far-infrared (FIR) telescope with an angular resolution of 1 arc min. The presence of a disk of cold dust is inferred from these FIR maps. High sensitivity and angular resolution radio continuum imaging at 325, 610 and 1280 MHz carried out using the Giant Metrewave Radio Telescope (GMRT), demonstrates the morphological contrast between the emission from the ionized gas and the thermal dust emission. The emission from the carriers of Unidentified Infrared Bands (UIBs) in the mid infrared 6-9μm as extracted from the Midcourse Satellite Experiment (MSX) survey (at 8, 12, 14 and 21 μm), compares rather well with the radio emission.

2 illus, 4 ref

014187   Dhar V K;Tickoo A K;Kaul M K;Kaul C L;Rannot R C;Yadav K K;Dubey B P;Koul R (Bhabha Atomic Research Centre, Nuclear Research Laboratory, Mumbai-400 085) : Artificial neural network-based image-cleaning method for atmospheric cerenkov imaging telescopes. Bull Astr Soc India 2003, 31(3-4), 495-6.

A novel image-cleaning method, based on the utilization of Artificial neural network (ANN) is shown to 'correctly' select more pixels in a Cerenkov images than in the conventional approach.

1 illus, 4 ref

014186   Deep A et al (NO, Inter University Centre for Astronomy and Asrophysics, Pune - 411 007) : Near infrared PICNIC imager (NIPI) - A progress report. Bull Astr Soc India 2003, 31(3-4), 465-6.

A preliminary design of Near Infrared PICNIC Imager was presented in 2002. Progress that has been made since then has been presented

1 illus, 3 ref

014185   Chatterjee S;Banyal R K;Prasad B R; Chandrasekharan K (NO, Indian Institute of Astrophysics, Bangalore 560 034) : On the resolving power of an Echelle grating in the presence of a corrugated wavefront of incidence. Bull Astr Soc India 2003, 31(3-4), 461-3.

2 illus, 3 ref

014184   Chandrasekhar T;Shah R;Mondal S (Asronomy & Astrophysics Division, Physical Research Laboratory, Ahmedabad 380 009) : Lunar occultations with infrared arrays. Bull Astr Soc India 2003, 31(3-4), 471-4.

Successfully observed the lunar occultation of a carbon star IRC+20120 and a M5 star IRC+10241 with the NICMOS sub array at the 1.2m Gurushikhar telescope. The integration times were respectively 5 millisec and 3 millisec per sample in the broad K band. The interval between two integrations was <126>16 millisec. FOV of the sub array was 10 arcsec x 10 arcsec. Details of the experiment and results are discussed.

2 illus, 2 ref

014183   Chandrasekhar T;Kikani P K;Mathur S N (Astronomy & Astrophysics Division, Physical Research Laboratory, Ahmedabad 380009) : Optical observations of a lunar meteor event during Lenid meteor showers in 2001. Bull Astr Soc India 2003, 31(3-4), 325-8.

Reports probable transient lunar meteor event observed during careful video recording of the unlit portion of the moon during the Leonid shower activity on 18th November 2001. A video CCD was attached to the 1.2m Gurushikhar telescope with a tele-compressor for observing an unit portion of the moon with a field of view of 3'.95 X 2'.75 Absolute time accuracy of 1 sec was maintained. Subsequent study of the video tape yielded five candidate events one of which has been independently observed. Details of the experiment, results and prospects of co-ordinated observations are discussed.

2 illus, 2 tables, 5 ref

014182   Bhattacharyya S;Bhatt N;Misra R;Kaul C L (Bhabha Atomic Research Centre, Nuclear Research Laboratory, Mumbai - 400 085) : The effect of non-thermal protons on the high energy spectra of black hole binaries. Bull Astr Soc India 2003, 31(3-4), 375-6.

Investigates the effect on the emitted spectrum of a black hole binary due to the presence of accelerated protons in the inner region of the accretion disk. The study shows that e^-e⁺ pairs and high energy γ-rays created in inelastic p-p collisions contribute mainly in the 1 - 10 MeV range and produce a broad feature in the spectrum in this energy range which can be verified by INTEGRAL and GLAST observations.

1 illus, 4 ref

014181   Bhatt N;Paul B;Koul C L (Bhaba Atomic Research Centre, , Trombay, Mumbai - 400 085) : Orbital evolution of the binary X-ray pulsar Her X-1. Bull Astr Soc India 2003, 31(3-4), 367-8.

Reports the discovery of a break in the orbital period evolution of Her X-1, coincident with a recent anomalous low state.

1 illus, 4 ref

014180   Bhat C K;Kaul R K (Bhabha Atomic Research Centre, Nuclear Research Laboratory, Trombay, Mumbai-400085) : Multi-fractal and wavelet analysis for cosmic ray mass composition studies using the TACTIC telescope. Bull Astr Soc India 2003, 31(3-4), 499-500.

Investigates the efficiency of multifractal and wavelet parameters of the simulated images of atmospheric Cerenkov events, in segregating the events in terms of primary mass. Finds that the fractal dimension D₆ and the wavelet dimension β₆ can be employed effectively for studying cosmic ray mass composition at <62>20 Te V energy with the TACTIC array.

1 illus, 2 ref

014179   Bhardwaj Anil (Space Physics Laboratory, Vikram Sarabhai Space Centre, Trivandrum 695022) : X-ray emissions from the Jovian system. Bull Astr Soc India 2003, 31(3-4), 159-66.

X-ray emissions from Jupiter, discovered by Einstein observatory and followed up by ROSAT, have been thought to be excited by energetic and highly changed sulphur and oxygen ions precipitating from the inner magnetosphere into the planet's polar regions. However, recent observations by Chandra telescope have revealed surprising new results, including mysterious pulsating (period 45 minutes) x-ray hot spot in the northern polar regions of Jupiter, that have called into question understainding of Jovian auroral x-rays. Further, X-rays from the moons of Jupiter-Io, Europea, and probably Ganymede and from the Io plasma torus have been discovered by the Chandra observatory. Presents a brief review of the X-ray emissions from the Jupiter, the Galilean satellites and the Io plasma torus.

4 illus, 30 ref

014178   Banerjee D P K;Ashok N M (NO, Physical Reasearch Laboratory, Ahmedabad-380 009) : IR spectroscopy of nova-like sources. Bull Astr Soc India 2003, 31(3-4), 181-6.

Near-IR spectroscopic and photometric observations of the eruptive variables V838 Mon and V445 Puppis in the JHK bands are reported. These objects erupted in nova-like explosions but evolved into rather unique and enigmatic objects. One of the unusual features of the V838 Mon spectra is the detection of several strong TiI lines in emission in the K band. These spectra also show the strong presence of the ¹²CO bands. Deep water bands at 1.4μm and 1.9μm are also seen later in the object's evolution. Blackbody fits to the JHK photometric data show that V838 Mon evolves to low temperatures between 2400-2600 K after its outburst. The spectra of V445 Puppis are found to be hydrogen dificient and unusually rich in CI lines leading to the possibility that it is a rare Helium nova. The nature of both the objects is discussed and it is shown that they do not fit into known categories of eruptive variables.

2 illus, 23 ref

014177   Baliyan K S;Ganesh S;Joshi U C;Glass I.S. (Physical Research Laboratory, , Ahmedabad - 380 009) : Near infrared survey of the galactic nuclear bulge region. Bull Astr Soc India 2003, 31(3-4), 403-5.

Inner 300 pc of the Galactic Center region is surveyed with the SIR IUS camera mounted on the Infra Red Survey Facility (IRSF) telescope of the SAAO, during June-July 2002, resulting the deepest near infrared view of the Milky Way Nuclear Bulge Region. Presents first results from this survey underlining the capabilities of the SIRIUS camera and the photometric procedures adopted in this work involving highly crowded star fields.

2 illus, 18 ref

014176   Balasubramanyam (NO, Raman Research Institute, Bangalore -560080) : Sub-millimeterwave efforts in India. Bull Astr Soc India 2003, 31(3-4), 231-6.

The submillimeter waveband (3 to 0.3 mm) is important for photometric and spectroscopic studies of the high redshift Universe and of the deeply embeddded star forming regions in the galaxy of the Sun and nearby galaxies. The upcoming Atacama Large Millimeterwave Array (ALMA) will have a large collecting area and high spatial resolution, but small field of view and correlation bandwidth. This creates both an opportunity and a need for an effective complement: a large single dish fitted with a modern photon detector array can be faster than ALMA for continuum source detection. Besides being powerful in its own right, such an instrument can also supply zero-spacing data for making more complete spectral line images with ALMA. The natural strength in having many high altitude desert sites in the Himalayas can be leveraged to take nascent submillimeter efforts to the frontiers of this new waveband. Building large submillimeterwave telescopes calls for unconventional approaches. The astronomical importance of the submillimeter waveband has been discussed, ongoing site survey efforts in the Himalayas has been presented and then put forth a novel way to build a large submillimeterwave antenna has been put forth.

1 illus, 10 ref

014175   Babu G S D;Jayakumar K;Velu C;Sujatha S (Vainu Bappu Observatory, Indian Institute of Asrophysics, Kavalur 635701) : Spectral line variations in the AP star HD 42536. Bull Astr Soc India 2003, 31(3-4), 337-9.

The Sr-Cr type chemically peculiar star HD 42536 (= HR 2195) was observed with the 2.34 meter Vainu Bappu Telescope, Kavalur during the period of November 1998 to April 1999. A total of 46 spectrograms were obtained in the wavelength region of 3900 Armstrong to 4300 Armstong at a linear dispersion of 0.65Armstrong per pixel. The equivalent widths of Sr (4077) and Cr (4172) have been found to be varying with a period of 0.58 ±0.02 day, the amplitudes being about 100 m Armstrong and 60m Armstrong respectively. This period is a resonance value of the period given by Manfroid and Mathys (1985).

2 illus, 4 ref

014174   Ashok N M;Banerjee D P K (NO, Physical Research Laboratory, Ahmedabad 380 009) : JHK Spectroscopy of the enigmatic variable V445 Puppis. Bull Astr Soc India 2003, 31(3-4), 343-4.

Near-IR spectroscopic observations are reported for the enigmatic, nova like, variable V445 Puppis. The near-IR spectra are hydrogen-deficient and unusually rich in CI lines. The spectra indicate that the object could be a rare Helium nova.

1 illus, 6 ref

014173   Anupama G C (NO, Indian Institute of Asrophysics, Bangalore 560 034) : The 2002 outburst of the recurrent nova IM Normae. Bull Astr Soc India 2003, 31(3-4), 345-6.

IM Nor was discovered as a possible nova in 1920, with a light curve that suggested similarity with slow novae such as DQ Her and T Pyx (Elliot & Liller 1972). A second outburst was discovered on 10 January 2002, when IM Nor was found to be at a red magnitude of 8.3 (Liller 2002). Subsequent observations confirmed the nova outburst, adding to the group of recurrent novae. The light curve of the recent outburst indicates it to be a moderately fast-slow nova with t₃<62><126>50 days (Kato et el 2002, Duerbeck el at 2002a). The spectral evolution of the outburst here presented, based on spectra obtained from VBO using the 2.34m VBT during 2002 Feb-Apr and in 2003 Feb, and those available in the literature.

2 illus, 7 ref

014172   Ananthakrishnan S;Kantharia N G;Nityananda R (NCRA-TIFR, Pune University Campus, Pune - 411007) : Extra-planar radio emission from edge-on disk galaxies. Bull Astr Soc India 2003, 31(3-4), 421-4.

2 illus, 4 ref

014171   Ambastha A;Gosain S (Udaipur Solar Observatory, Physical Research Laboratory, P.O. Box No. 198, Udaipur -313004) : White light and emission line polarization of solar corona during TSE of June 21, 2001. Bull Astr Soc India 2003, 31(3-4), 295-6.

Coronal intensity and polarization maps have been obtained for the total eclipse (TSE) of June 21, 2001, observed from Lusaka, Zambia (location: 28°17.5'E15°24.5'S, Alt. 1300 mtr) at broadband Hα 6563 Armstrong(FWHM 80 Armstrong,) as well as, around the coronal emission lines 5303 Armstrong (FWHM 12 Armstrong and 6374 Armstrong (FWHM 12 Armstrong). The results are discussed.

10 ref

014170   Ambastha A;Basu S;Antia H M (Udaipur Solar Observatory, Physical Research Laboratory, P.O. Box No. 198, Udaipur - 313004) : Excitation of solar p-mode oscillations by flares. Bull Astr Soc India 2003, 31(3-4), 319-20.

Solar flares release large amounts of energy at different layers of the solar atmosphere. It is, therefore, expected that major flares would be able to excite waves, thereby affecting the p-mode oscillation characteristics. From the analysis of MDI data, it has been found that power in p-mode appears to increase for some flares, beyond the normal values expected from the influence of magnetic field.

1 illus 8 ref

012112   Pant T K;Suhasini R;Gurubaran S;Sridharan R (Space Physics Laboratory, , Thiruvananthpuram 695 002) : An improved data reduction technique for the retrieval of the doppler parameters from interference fringes obtained by a high resolution Fabry-perot spectrometer. Indian J Radio Space Phys 2003, 32(6), 329-36.

A new data analysis scheme for retrieving Doppler temperatures from high resolution Fabry-Perot spectrometer fringes is described. Important aspects of parametric representation of the instrument function, convolution and the various instrument-broadening functions are discussed in detail. Complete theoretical background highlighting the method for recovering Doppler parameters and involved errors using the instrument-broadened airglow emission profile are provided. Further, a criterion is set to select proper airglow line profiles for the analysis.

4 illus, 24 ref

010092   Nath B (NO, Raman Research Institute, Sadashivnagar, Bangalore- 560 080) : Compton scattering in Astrophysics. Phys Educ 2003, 19(4), 293-7.

After reviewing the basic principles of Compton scattering, discusses a few examples from astrophysics, including inverse Compton scattering.

2 illus, 3 ref

010091   Narlikar J V (NO, Inter-University Centre for Astronomy and Astrophysics, Post Bag 4, ganeshkhind, Pune 411 007) : Spectral shifts in Astronomy. Phys Educ 2003, 19(4), 285-92.

Describes how shifts in the lines in the spectrum of an object can arise due to various physical process. In particular, it discusses the Doppler effect, the gravitational redshift and the cosmological redshift. It then shows that all three shifts can be unified in a single picture.

2 illus, 6 ref

019988   Thakur V K;Singha A S (Material Science Laboratory, National Institute of Technology, Hamirpur-177 005, Email: assingha@gmail.com) : Natural fibres-based polymers: part I-mechanical analysis of pine needles reinforced biocomposites. Bull Mater Sci 2010, 33(3), 257-64.

Lack of resources and increasing environmental pollution has evoked great interest in the research of materials that are friendly to our health and environment. Polymer composites fabricated from natural fibres is currently the most promising area in polymer science. Keeping in view the various advantages of natural fibres, in current series of green composites a study on natural fibre reinforced polymer composites has been made. This paper presents the results of an experimental series designed to assess the possibility of Pine needles as reinforcing material in polymer composites. First of all, urea-formaldehyde resin was synthesized and optimized by evaluating its mechanical properties. Optimized resin was reinforced with employing Pine needles of different dimensions such as particle reinforcement, short fibre reinforcement and long fibre reinforcement. Experimental results obtained shows that mechanical properties such as tensile strength, compressive strength and wear resistance of UF resin increases to a considerable extent when reinforced with Pine needles. Further it has been observed that particle reinforcement is more effective as compared to short fibre and long fibre reinforcement. These results suggest that Pine needles can be potential candidates for use in natural fibre reinforced polymer composites. Thermal and morphological studies of these composites have also been carried out.

7 illus, 2 tables, 23 ref

019987   Sriramkumar L (NO, Harish-Chandra Research Institute, Chhatnag Road, Jhunsi, Allahabad-211 019, Email: sriram@hri.res.in) : Introduction to inflation and cosmological perturbation theory. Curr Sci 2009, 97(6), 868-86.

This article provides an introductory review of inflation and cosmological perturbation theory. I begin by motivating the need for an epoch of inflation during the early stages of the radiation dominated era, and describe how inflation is typically achieved using scalar fields. Then, after an overview of linear cosmological perturbation theory, I derive the equations governing the perturbations, and outline the generation of scalar and tensor perturbations during inflation. I illustrate that slow-roll inflation naturally leads to an almost scale-invariant spectrum of perturbations, a prediction that seems to be in good agreement with the measurements of the anisotropies of the cosmic microwave background. I describe the constraints from the recent observations on some of the more popular models of inflation. I conclude with a brief discussion on the status and certain prospects of the inflationary paradigm.

3 illus, 81 ref

019986   Sashadri T R (Physics and Astrophysics Dep, Delhi Univ, Delhi-110 007, Email: sashadri.tr@physics.du.ac.in) : Learning about the universe from cosmic microwave background radiation. Curr Sci 2009, 97(6), 858-67.

The Cosmic Microwave Background Radiation (CMBR) is a nearly isotropic radiation that carries information about the state of the Universe in its early phase and about different physical processes that occur at different times during the course of its evolution. The high degree of isotropy is a compelling evidence of the inflationary model of the Universe. The nature of specific features on the CMBR like the minute level of temperature anisotropy and polarization can narrow down the parameters which govern the evolution of the Universe. In these features the information about the initial conditions, evolution, geometry as well as the material content of the Universe is encoded. I have given in this review an overview of the physics involved in CMB studies and what it tells us about the Universe. I have also discussed the observations from 5-year data of WMAP and their implications.

4 illus, 35 ref

019985   Sami M (Theoretical Physics Centre, Jamia Millia Islamia, New Delhi-110 025, Email: sami@iucaa.ernet.in) : Primer on problems and prospects of dark energy. Curr Sci 2009, 97(6), 887-910.

This review on dark energy is intended for a wider audience, beginners as well as experts. It contains important notes on various aspects of dark energy and its alternatives. The section on Newtonian cosmology followed by heuristic arguments to capture the pressure effects allows us to discuss the basic features of physics of cosmic acceleration without actually resorting to the framework of the general theory of relativity. The brief discussion on observational aspects of dark energy is followed by a detailed exposition of underlying features of scalar field dynamics relevant to cosmology. The review includes pedagogical presentation of generic features of models of dark energy and its possible alternatives.

9 illus, 72 ref

019984   Patel P;Srivastava H S;Navalgund R R (Space Applications Centre, Indian Space Research Organization, Satellite Road, Ahmedabad-380 015, Email: parul@sac.isro.gov.in) : Use of synthetic aperture radar polarimetry to characterize wetland targets of keoladeo national park, Bharatpur, India. Curr Sci 2009, 97(4), 529-37.

Timely and accurate information about various habitats of a wetland ecosystem is necessary for the assessment, monitoring and management of a wetland. In this article, the state-of-the-art Polarimetric Synthetic Aperture Radar (PolSAR) data have been analysed to characterize various components of a wetland ecosystem. SAR polarimetry has received negligible attention in India, mostly owing to lack of data over the Indian sub-continent. With a recent DLR-ESAR (Ex-pcrimental-SAR) flight over India, it was possible to conduct a detailed, planned experiment to explore the potentials of SAR polarimetry. This study has been carried out using fully polarimetric, multi-frequency DLR-ESAR data over parts of a world heritage and Ramsar site, the Keoladeo National Park, Bharatpur, India. Scattering models based on physical principles have been applied to characterize the wetland targets like open-water habitat, various types of aquatic vegetation with or without standing water, along with various species of forested areas. Entropy, alpha angle and anisotropy have been derived by performing eigen vector-based target decomposition on L- and P-bands fully polarimetric SAR data, enabling us to understand the differences in wetland targets in terms of their scattering behaviour at the L- and P-bands. A significant outcome of this study is that it explores and demonstrates the potential of the state-of-the-art technique of PolSAR for characterizing scattering behaviour of various components of a wetland ecosystem, which is a less explored application of SAR, particularly in the Asian countries.

6 illus, 1 table, 30 ref

019983   Parveen M N;Ghosh B (NO, Geological Survey of India, Southern Region, Kerala Unit, Thiruvananthapuram-695 014, Email: bghosh_geol@hotmail.com) : Submarine volcanic facies and its implication as possible tracker of sulphide mineralization - a study from Jilharidev area, betul belt, Central india. Curr Sci 2009, 97(5), 670-9.

Felsic volcaniclastic rock forms part of host rock sequences in many of the base metal prospects in the Betul belt. However, the volcanic facies, fragmentation processes and depositional environments in mineralized areas are poorly understood because of the effects of synvolcanic hydrothermal alteration and subsequent regional metamorphism. A section in the Kanhan river valley, which exposes volcanics with relatively well preserved primary textures was mapped in detail to understand the disposition of the felsic volcanics namely rhyolite and to identify the various volcanic facies present within them (viz. massive, flow-banded, autobreccia and hyaloclastite). Four different facies types were distinguished based on phenocryst type, size and abundance. Presence of hyaloclastite autoclastic rocks and pillow lava and absence of pyroclastic deposits suggest a deep, submarine, passive, effusive-type volcanic setting. Auto-breccia and hyaloclastite in the felsic volcanic sequence of the present study area lying within Betul Belt has similarities with well-known volcanic-hosted massive sulphide (VHMS) bearing areas in other parts of the world. Proper identification of the volcanic facies within highly altered host rocks near the deposits can help in building up facies models that would establish the genetic relationship between sulphide mineralization and the host-rock facies which in turn will have important implications for base metal exploration in the area.

4 illus, 1 table, 37 ref

019982   Mitra A (Theoretical Astrophysics Section, Bhabha Atomic Research Centre, Mumbai-400 085, Email: amitra@barc.gov.in) : Quantum information paradox: real or fictitious?. Pramana J Phys 2009, 73(3), 615-22.

One of the outstanding puzzles of theoretical physics is whether quantum information indeed gets lost in the case of black hole (BH) evaporation or accretion. Let us recall that quantum mechanics (QM) demands an upper limit on the acceleration of a test particle. On the other hand, it is pointed out here that, if a Schwarzschild BH exists, the acceleration of the test particle would blow up at the event horizon in violation of QM. Thus the concept of an exact BH is in contradiction with QM and quantum gravity (QG). It is also reminded that the mass of a BH actually appears as an integration constant of Einstein equations. And it has been shown that the value of this integration constant is actually zero! Thus even classically, there cannot be finite mass BHs though zero mass BH is allowed. It has been further shown that during continued gravitational collapse, radiation emanating from the contracting object gets trapped within it by the runaway gravitational field. As a consequence, the contracting body attains a quasi-static state where outward trapped radiation pressure gets balanced by inward gravitational pull and the ideal classical BH state is never formed in a finite proper time. In other words, continued gravitational collapse results in an 'eternally collapsing object' which is a ball of hot plasma and which is asymptotically approaching the true BH state with M = 0 after radiating away its entire mass energy. And if we include QM, this contraction must halt at a radius suggested by the highest QM acceleration. In any case no event horizon (EH) is ever formed and in reality, there is no quantum information paradox.

27 ref

019981   Layek Samar;Verma H C (Physics Dep, Indian Institute of Technology, Kanpur-208 016, Email: hcverma@iitk.ac.in) : Meteorite fall at Karimati village, Hamirpur, Uttar pradesh. Curr Sci 2009, 97(5), 632-3.

2 illus, 2 tables, 3 ref

019980   Dhariwal A;Parihar R (Civil Engineering Dep, Faculty of Engineering, Jai Narain Vyas Univ, Jodhpur-342 011, Email: rdevparihar@yahoo.com) : Shrinking of worlds armour-the ozone. Asian J chem envir Res 2011, 4(1), 44-9.

The paper deals with ozone layer depletion and its effects round the globe. It's also include classification of good and bad zone, process of ozone depletion, common myths surrounding the globe, effects of ozone depletion and ray of hope for recovery of ozone layer.

6 illus, 7 ref

019979   Dadhich N (NO, Inter-Univ Centre for Astronomy & Astrophysics, Post Bag 4, Pune-411 007, Email: nkd@iucaa.ernet.in) : Characterization of the lovelock gravity by Bianchi derivative. Pramana J Phys 2010, 74(6), 875-82.

The second-order quasilinear differential operator as a second-rank divergence-free tensor in the equation of motion for gravitation could always be derived from the trace of the Bianchi derivative of the fourth-rank tensor, which is a homogeneous polynomial in curvatures. The existence of such a tensor for each term in the polynomial Lagrangian is a new characterization of the Lovelock gravity.

9 ref