019638   Dole B N;Shah S S (Phys Dep, J E S Research Centre, J E S College, Jalna-431 203) : Some properties of BSCCO-Ag added high temperature superconductors. Indian J Phys 2005, 79(1), 81-4.

The samples of (Bi-Pb)₂ Sr₂ Ca₂ Cu₃ O_10+δ system were prepared by conventional solid state reaction method with silver addition from 0 to 50% Some interesting results have been obtained. It has been observed from the X-ray diffraction data that the enhancement in 2212 phase reduction in 2223 phase may exhibit the suppress on of T_c at certain concentration of Ag wt%. It is also viewed from X-ray diffraction and intensity data that the addition of silver of 30 to 40%, does not deteriorate the sample quality of (2223) compounds. But addition of silver beyond this, may lead to formation of 2212 phase in increasing proportion.

3 illus, 4 tables, 17 ref

019637   Dianov E M;Bufetov I a;Frolov A A (Fiber Optics Research Center, A M Prokhorov General Physics Institute, The Russian Academy of Scienc, 38 Vavilov Street, 119991, Moscow, Russian Federation) : Catastrophic damage in specialty optical fibers under cw medium power laser radiation. J Optics 2004, 33(3), 171-80.

Authors investigated some features of the catastrophic damage propagating along fibers of different type under the action of laser radiation. All fibers investigated (silica based ordinary and microstructured fibers, fluoride and chalcogenide fibers) can be damaged by laser radiation, but the processes of destruction in silica based fibers and in fluoride and chalcogenide fibers are of quite different nature. The destruction process in silica based fibers is accompanied by the plasma (optical discharge) formation in the core region. In fluoride and chalcogenide fibers this process is characterized by thermal decomposition and embrace the whole cross-section of the fiber. For the first time the catastrophic damage in microstructured fibers has been investigated. For this type of fibers the threshold intensity for the catastrophic damage process is higher than that for conventional fibers. The phenomenon of silica fiber cladding destruction by the fiber fuse effect has been observed in the case of preliminary reduction of its mechanical strength. The cladding destruction leads to the termination of the optical discharge propagation in a fiber that can be used to confine the fiber fuse effect in fiber systems.

6 illus, 3 tables, 16 ref

019636   Choudhuri P R;Lu C (Institute for Infocomm Research, Innovation Centre, 18 Nanyang Drive,, , , Email: roycp@i2r.a-star.edu.sg) : Design and realisation of asymmetric core index guiding photonic crystal fiber with high birefringence characteristics. J Optics 2004, 33(3), 187-94.

Investigates the modal birefringence behaviour of a near-elliptic core indexguiding photonic crystal fiber (PCF) intended for realizing high birefringence characteristics. For this analysis, authors has devised a semi-vectorial finite difference (FD) algorithm in combination with the perturbation correction technique of mode calculation. The approach yields accurate results, simple to implement, and much faster than any of the existing methods. The effectiveness of design analysis has been verified by comparing the results with otherwise known solutions. Using this analysis as a design recipe, we have realized PCF of reasonably high birefringence characteristics.

8 illus, 1 table, 17 ref

019635   Ananda Kumari R;Chandramani R (Physics Dep, Sree Siddaganga College for Women, Tumkur-572 101) : Electrical conductivity and dielectric properties of KH₂PO₄ crystals modified with KBr and NaBr. Indian J Phys 2005, 79(1), 31-5.

Pure KH₂ PO₄(KDP) and KDP crystals containing KBr and NaBr with/without gold doping were grown by slow evaporation technique. All the grown crystals were <103><255>- irradiated using ⁶⁰ Co source. Electrical conductivity measurements were carried out perpendicular to the unique direction before and after <103><255>-irradiation. The present measurement shows that the conductivity of KDP crystals increases with the addition of KBr and NaBr and with gold-doping as well as temperature. Computed values of activation energies from the conductivity measurements are given. Dielectric constant is measured as a function of frequency. Study confirms the contribution of space charge polarization.

11 illus, 2 tables, 12 ref

019634   Afify H H;EL-Hefnawi S;Eliwa A;Abdel-Naby M; Ahmed N M (Solid State Physics Dep, National Research Centre, Cairo, Egypt) : Preparation of pure ZnO films having an almost one plane of growth. Indian J Phys 2005, 79(1), 19-23.

Spray pyrolysis technique was used to prepare zinc oxide films on glass substrate. All the spraying parameters are kept constant except the deposition temperature and the precursor solvent composition. The used solvent was a mixture of distilled water and methyl alcohol. The empirical formula is H ₂ O _(100-x) and CH₃OH_(x). The characteristic planes of the deposited ZnO films at 698° K for 30 minutes depends on the value of x. For x=0 or 100, the deposited ZnO films have most of the characteristic planes. When 50<62> x <62> 20, almost one plane (002) is appeared. This behaviour could be attributed to the modulation of the dielectric constant of distilled water (80) by the addition of methyl alcohol (32.6). The deposition temperature has nearly the same effect on zinc oxide films prepared from the modulated solvent. The ZnO films deposited around 673° K show the most characteristic planes of ZnO while those deposited above this temperature up to 773° K show almost one plane. The relative crystallite size was calculated by applying Scherrer's relation on the intensive plane in XRD pattern. It is found that the values of the calculated crystallite size is ranged from 30 to 55 nm as the substrate temperature increases. The measured transmittance is found to be higher for oriented films than those oriented randomly.

6 illus, 1 table, 28 ref

018520   Ying-le L;Ji-ying H (Box 273,, Science School, Xidian Univ, Xi'an, 712000, China, Email: liyinglexidian@yahoo.com.cn) : Analytic solution of scattering field and its characteristics for an ellipsoid. Indian J Radio Space Phys 2004, 33(5), 301-5.

The analytic solution of scattered field by an ellipsoid of any shape is presented utilizing transformation of coordinates. The cross polarization discrimination (XPD) of electromagnetic waves induced by the ellipsoid is derived and simulated. Results show that XPD changes depend on ellipsoidal size, shape and observing location. The XPD varies smoothly with the shape at the forward points in comparison with that at the backward points. For a given shape, measuring in opposition to the incident direction provides the maximum in XPD.

7 illus, 6 ref

018519   Vijayalaxmi K K;D'Souza M P (Studies in Applied Zoology Dep, Mangalore Univ, Mangalagangotri-574 199) : Studies on the genotoxic effects of anticancer drug carboplatin in in vivo mouse. Int J Hum Genet 2004, 4(4), 249-55.

Genotoxicity of platinum antitumor agent carboplatin (Cbp) was investigated by using mouse in vivo test system. Three different doses of carboplatin viz., 30, 60 and 90 mg/kg b.w were used for the experiment. Fetal liver micronucleus (MN) test and sperm abnormality assay were used as the test parameters. Cyclophosphamide (50 and l00mg/kg b.w) was used as positive control and distilled water formed the negative control. Both the chemicals were administered intraperitoneally to experimental animals. MN and sperm preparations were made at 24 hr. and 35 days respectively. Carboplatin induced significant MN both in the fetal liver and the maternal bone marrow at different doses. It also induced high frequency of abnormal sperms at higher doses and the effect was significant at all the 3 doses tested.

4 tables, 40 ref

018518   Tiwari V K;Bhardwaj V;Saini J S;Kumar P; Sharma K B;Bhatnagar D (Microwave Lab., Physics Dep, Rajasthan Univ, Jaipur-302 004) : Investigations of radiation properties of a circular disk microstrip antenna with a slot. Indian J Radio Space Phys 2004, 33(5), 336-40.

The radiation characteristics of a circular disc microstrip antenna (CDMAS) carrying a narrow slot on its surface are investigated experimentally and measured results are compared with computed results. The theoretical analysis of this an-tenna is carried out by applying cavity model-based modal expansion technique. A reasonably good agreement between computed and measured results is recorded which verifies the theoretical formulation applied in this work.

6 illus, 2 tables, 10 ref

018517   Sengwa R J;Soni A;Ram B (Microwave Research Laboratory, Physics Dep, J N V Univ, Jodhpur-342 005, Rajasthan) : Dielectric behaviour of shale and calcareous sandstone of Jodhpur region. Indian J Radio Space Phys 2004, 33(5), 329-35.

Dielectric permittivity ε' and loss ε" of dry and water saturated shale, sandy sandstone (sandy shale) and calcareous sandstone of Jodhpur region were studied at room temperature in the frequency range from 100 Hz to 100 kHz and also at 10.1 GHz. It is observed that the ε' values of these samples decrease with increase in frequency. The complex plane plots (ε" versus ε") of these geological materials are Cole-Cole arcs. The low frequency limiting dielectric constant ε₀ high frequency limiting dielectric constant ε_∝, dielectric relaxation time τ and distribution parameter a of these samples have been determined from these Cole-Cole plots. The ac conductivity of dry and water-saturated samples has also been reported. The large enhancement in the permittivity value of water-saturated samples was found due to electrochemical polarization. Further it is observed that the increase in ε' value of water saturated shale and sandy sandstone is proportional to the volume fraction of water absorbed in the samples. The effect of the density, porosity, grain sizes and chemical composition on the frequency dependent dielectric permittivity of these samples has been explored.

6 illus, 3 tables, 33 ref

018516   Saju S;Jamema S V;Dinesh Kumar M;Narayanan S S;Kinhikar R A;Deshpande D D (Medical Physics Dep, Tata Memorial Hospital, Parel, Mumbai-400 012) : Comparison of IAEA TRS 398, TRS 381 and AAPM TG 51 protocols for high energy electron beams. J med Phys 2004, 29(1), 9-16.

Compares the measured absorbed dose to water (D_w) between various protocols, such as IAEA TRS 398, TRS 381 and AAPM TG 51, for the clinical electron energies of 6,9, 12,15 and 18 MeV. Two cylindrical chambers, PTW 30001 and NE 2571, and two plane parallel chambers, PTW Roos and PTW Markus chambers, were used. All chambers have been calibrated for ⁶⁰ Co quality, in terms of both absorbed dose (N_D,W) and air kerma (N_K), traceable to Secondary Standards Dosimetry Laboratory (SSDL), BARC, India. Absorbed dose to water ratios TRS 398/TG 51 and TRS 398/TRS 381 are graphically represented as a function of R⁵⁰. To study the difference in the absorbed dose to water, basic data from all the protocols are analyzed. In case of cylindrical chambers and plane parallel Roos chamber, maximum deviations of 0.7% between TRS 398 and TG 51 and 2% between TRS 398 and TRS 381 are observed. In the case of Markus chamber, maximum deviations of 1.8% between TRS 398 and TG 51 and 0.5% between TRS 398 and TRS 381 are obtained. Between TRS 398 and TRS 381, sources of variation are calibration factors such as N_{D, air} & N_DW and S_W,air data. Though the difference between the protocols is not very significant, the change could be justified for the homogeneity in dosimetry.

4 illus, 6 tables, 11 ref

018515   Roy M;Agarwal V K (Physics Dep, M.L. Sukhadia Univ, Udaipur- 313 002, Email: mroy1959@yahoo.co.in) : X-Ray, SEM, EDAX and thermal analysis of water dissolved solids. Int J chem Sci 2004, 2(4), 657-64.

Water dissolved solids have been extracted by conventional boiling and filtering technique.The extracted solids have been characterized by X-ray diffraction, scanning electron microscopy (SEM), energy dispersive X-ray microanalysis. (EDAX), thermogravimetric analysis (TGA) and dc electrical conductivity measurement methods. Comparision of the results of the as extracted and heat treated (up to 1200 ° C) samples show that the heat treated composite sample is thermally very stable, showing very high value of electrical resistivity almost temperature independent and hence, showing very high dielectric strength, useful for high temperature dielectric devices.

5 illus, 1 tables, 5 ref

018514   Naik Y (Radiopharmaceuticals Div, Bhabha Atomic Research Centre, Mumbai-400 085) : Preparation of intermetallic compounds and thin films of zirconium and titanium for hydrogen storage. Bull Indian Vacuum Soc 2004, 7(4), 17-22.

zirconium based intermetallic compound for the safe storage of hydrogen isotopes have been developed. Pressure composition isotherms for the reaction of the intermetallic compound with hydrogen is studied with a view to find its suitability for storage, delivery and safe transport. Storage capacity of the intermetallic compound is found to be 169 mL/g of ZrCo at room temperature with equilibrium plateau pressure of less than 10^-4 cm of Hg. Method of permanent storage of hydrogen in the form of thin film of titanium hydride have been developed. Importantce of cacuum technology in the preparation of both the intermetallic compounds and thin films of the metal for hydrogen storage is highlighted.

4 illus, 1 table, 4 ref

018513   Mohanty M;Pradeep Kumar P (Physics Dep, Pune Univ, Pune-411 007) : Electric field measurements of overhead thunderstorm at a tropical station using network of plate antennas. Indian J Radio Space Phys 2004, 33(5), 310-5.

Electric field measurements due to lightning discharge from overhead thunderstorms were carried out by using a network of five plate antennas which covered an area of 6 km² over Pune, a tropical station and a plateau region about 560 m above mean sea level. Three ground lightning discharges from two thunderstorms were analyzed. From the field measurements the height and magnitude of the charge centre has been determined. Two of the ground discharges analyzed originated from the lower positive charge pocket and were located below the freezing level. The negative charge centre is located above the freezing level. The recovery time of electric field due to positive discharge (positive charge getting destroyed in the cloud) is about three times more than that of the field recovery after a negative discharge.

8 illus, 1 tables, 16 ref

018512   Calla O P N;Baruah A;Das B;Mishra K P;Kalita M;Haque S S (NO, International Centre for Radio Science, A-23, Shastri Nagar, Jodhpur-342 003) : Emission and scattering behaviour of dry soils from northeast India. Indian J Radio Space Phys 2004, 33(5), 321-8.

With the database of the dielectric constants of four dry soils from Assam and one dry soil from Meghalaya, the computations of emissivity and scattering coefficient have been carried out using emissivity model and perturbation model, respectively. The database of estimated emissivity and scattering coefficient have been generated at different frequencies of X-band from 8 GHz to 10 GHz. The estimations are made at 12 different angles of incidence and for both vertical and horizontal polarization. The values of emissivity and scattering coefficient can be used for designing passive and active remote sensing sensors.

10 illus, 2 tables, 7 ref

018511   Bhushan K G;Gadkari S C;Yakhmi J V (Bhabha atomic Research Centre, , Trombay, Mumbai-400 085) : A new design for triode sputter ion pump element. Bull Indian Vacuum Soc 2004, 7(4), 3-9.

A new pumping element has been developed for the triode sputter ion pump based on electromagnetic field simulations of a penning cell. The new element gives a higher pumping speed for the same volume as compared to the standard element based on titanium strips. This is attributed to the different geometrical structure of the cathode, which enhances the pumping by inducing the production of larger numbers of energetic neutral getter atoms. This also results in obtaining better pumping speed for inert gases like argon and helium.

4 illus, 15 ref

018510   Anjaria K B;Rao B S (Radiological Physics and Advisory Div, Bhabha Atomic Research Center, Trombay, Mumbay-400 085) : Effect of tumour promoter anthralin on Gamma radiation and 4-nitroquinoline 1-oxide induced genotoxicity in diploid yeast. Int J Hum Genet 2004, 4(4), 243-8.

The potentiating effect of tumour promoter anthralin on gamma radiation and 4-Nitroquinoline 1-oxide (4-NQO)induced gene conversion and back mutation was studied using diploid yeast Saccharomyces cerevisiae D7. Cells were exposed to 20-400 Gy of gamma radiation and plated on media without anthralin or containing 0.05-10 mg/ml of anthralin. In another set of experiments, cells were treated with 0.15-0.5 μM 4-NQO and plated on media without anthralin or containing 0.05-0.5 μg/ml of anthralin. The results indicated that anthralin did not modify gamma radiation induced gene conversion or back mutation. Anthralin, however, was found to enhance 4-NQO induced back mutation but not gene conversion. The enhancement was highest with the lowest concentration of anthralin and it decreased subsequently as anthralin concentration was increased.

6 tables, 36 ref

017474   Walia M S;Jain S C;Mahapatra P K;Singh M; Singla M L (Material Research Div, Central Scientific Instruments Organisation, Sector 30 C, Chandigarh-160 030, Email: prasant22@yahoo.com ) : Microcontrollr (MCS-51) based optoelectronic system for the determination of metal and non metal ions. J scient ind Res 2005, 64(3), 181-4.

An optoelectronic system using Microcontroller 89C51 for measurement of concentration, absorption and transmission of inorganic phosphate phosphorous is described. Phosphorous reacts with potassium antimony tartrate and ammonium molybdate solution to form phosphoantimonyl molybdate complex, which on reduction with ascorbic acid forms blue colour. This blue coloured complex shows absorption maxima at 695 nm and obeys Lambert-Beer's law in the concentration range of 0.05-1.00 ppm. Tungsten lamp is used as a light source with a grating (600 lines/mm) to obtain a linear spectrum. A sine drive is used along with the stepper motor that can adjust the grating to achieve the desired wavelength (695 nm). Silicon photodiode is used as a detector having peak spectral response at 800 nm.

2 illus, 1 table, 6 ref

017473   Uma Sankar S (Physics Dep, IIT Bombay, Powai, Mumbai-400 076) : Long Baseline neutrino oscillation experiments. Proc Indian Natn Sci Acad-Pt A 2004, 70(1), 63-9.

Discusses the physics motivations for long baseline neutrino experiments and the strategies that are being used and planned at these experiments. A summary of the experiments that are running or has are being constructed or have been approved been given. Very briefly, Some of the studies done for planning experiments in future have been discussed.

1 illus, 38 ref

017472   Singh N;Jain S C;Aggarwal A K;Bajpai R P (Coherent Optics Division, Central Scientific Instruments Organization, Sector 30, Chandigarh-160 030, Email: nsmehla@rediffmail.com ) : Fibre Bragg grating writing using phase mask technology. J scient ind Res 2005, 64(2), 108-15.

Fibre Bragg gratings (FBGs) are novel components of communication and sensors. The technique commonly employed for production of FBGs involves exposure of photosensitive germanosilicate fibre cores to intense excimer laser radiation through an optical phase mask located in close proximity of the fibre. FBGs were written using this technique in two different fibre samples and their strain and temperature sensing characteristics were investigated. The paper describes the techniques used for fabrication and their characteristic studies.

10 illus, 24 ref

017471   Sarkar S (Physics Dep, Oxford Univ, 1 Keble Road, Oxford OX1 3NP (UK)) : Neutrinos from the big bang. Proc Indian Natn Sci Acad-Pt A 2004, 70(1), 163-77.

The standard Big Bang cosmology predicts the existence of an, as yet undetected, relic neutrino background, similar to the photons observed in the cosmic microwave background. If neutrinos have mass, then such relic neutrinos are a natural candidate for the dark matter of the universe, and indeed were the first particles to be proposed for this role. This possibility has however been increasingly constrained by cosmological considerations, particularly of large-scale structure formation, thus yielding stringent bounds on neutrino masses, which have yet to be matched by laboratory experiments. Another probe of relic neutrinos is primordial nucleosynthesis which is sensitive to the number of neutrino types (including possible sterile species) as well as to any lepton asymmetry. Combining such arguments with the experimental finding that neutrino mixing angles are large, excludes the possibility of a large asymmetry and disfavours new neutrinos beyond those now known.

5 illus, 185 ref

017470   Sarkar C;Kimothi S;Bhattacharya B K;Dadhwal V K (Crop Inventory and Modeling Div, Agriculture Resources Group, RESIPA, Space Applications Centre (ISRO), Ahmedabad-380 015) : Characterisation of diffuse radiation fraction at selected stations over India. J Agrometeorol 2004, 6(Spl, Iss), 237-41.

The relation between atmospheric transmissivity (T) and diffuse radiation fraction (D) was studied using daily radiation data from India Meteorological Department (IMD) over 18 land stations at daily as well as hourly (10:00 hrs and 13:00 hrs IST) measurements between July 1998 to June 1999. Using the atmospheric transmissivity threshold criteria of T<62>0.35 as indicative of clear sky and T <60>0.35 for cloudy sky, linear clear sky models were developed and R² varied from 0.685 to 0.861 and from 0.746 to 0.887 for inland and coastal stations, respectively. The model coefficients were similar to those reported from globally validated models. Station-wise regression for cloudy sets yielded poor correlation, quadratic fits with R² (0.12 to 0.744 and from 0.512 to 0.615 for pooled datasets for daily and hourly observations respectively). The distinct linear regression for clear sky conditions for inland (Bhopal) and coastal (Mumbai) stations indicated that the presence of higher atmospheric water vapour content in latter could produce 10-15 percent higher diffuse fraction. The seasonal effect, i.e., effect of solar zenith angle was also investigated. Clear and cloudy sky T-D models would be useful in mapping diffuse fraction, insolation and PAR from transmissivity or clearness index, which can be obtained from INSAT geostationary satellite database.

3 illus, 2 tables, 12 ref

017469   Raychaudhuri A (Physics Dep, Calcutta Univ, 92 Acharya Prafulla Chandra Road, Kolkata-700 009) : Neutrino oscillations: a solution to anomalies in observations of solar, atmospheric and laboratory neutrinos. Proc Indian Natn Sci Acad-Pt A 2004, 70(1), 179-88.

Evidence in support of neutrino oscillations is now compelling. A pedagogic introduction to vacuum neutrino oscillations and resonant flavour conversion is presented. The results from solar and atmospheric neutrinos are discussed and their combined implications on neutrino properties are outlined. Laboratory tests of neutrino oscillations are also summarized.

1 table, 35 ref

017468   Pakvasa S;Valle J W F (Physics and Astronomy Dep, Hawaii Univ, Manoa 2505 Correa Road, Honolulu, Hawaii 96822 (USA)) : Neutrino properties before and after Kamland. Proc Indian Natn Sci Acad-Pt A 2004, 70(1), 189-222.

Reviews neutrino oscillation physics, including the determination of mass splittings and mixings from current solar, atmospheric, reactor and accelerator neutrino data. A brief discussion is given of cosmological and astrophysical implications. Non-oscillation phenomena such as neutrinoless double beta decay would, if discovered, probe the absolute scale of neutrino mass and also reveal their Majorana nature. Non-oscillation descriptions in terms of spin-flavour precession (SFP) and non-standard neutrino interactions (NSI) currently provide an excellent fit of the solar data. However they are at odds with the first results from the Kam LAND experiment which imply that, despite their theoretical interest, non-standard mechanisms can only play a sub-leading role in the solar neutrino anomaly. Accepting the LMA-MSW solution, one can use the current solar neutrino data to place important restrictions on non-standard neutrino properties, such as neutrino magnetic moments. Both solar and atmospheric neutrino data can also be used to place constraints on neutrino instability as well as the more exotic possibility of CPT and Lorentz Violation. The potential of future data from experiments such as KamLAND, Borexino and the upcoming neutrino factories in constraining non-standard neutrino properties have been illustration.

30 illus, 148 ref

017467   Narasimham V S (Tata Institute of Fundamental Research, , Mumbai-400 005) : Perspectives of experimental neutrino physics in India. Proc Indian Natn Sci Acad-Pt A 2004, 70(1), 11-25.

A description of the early work on experimental observation and study of cosmic ray neutrinos in India is sketched here. This includes experiments to measure the variation of intensity of cosmic ray muons down to great depths underground, the first detectors for neutrino detection, and the consolidation of neutrino data using large scale proton decay experiments. Also included is a brief description of special (Kolar) events recorded in the KGF detectors, that defy explanation on the basis of normal muon or neutrino interactions. Results from the neutrino experiments conducted in other laboratories around the same time period as well as those recorded in all the first-generation proton decay experiments have been reviewed briefly.

13 illus, 4 tables, 38 ref

017466   Mukhopadhyay B (Harish-Chandra Research Institute, , Chhatnag Road, Jhusi, Allahabad-211 019) : Supersymmetry and neutrino mass. Proc Indian Natn Sci Acad-Pt A 2004, 70(1), 239-49.

The existence of neutrino mass and mixing is a strong pointer towards physics beyond the Standard Model. An overview of the possibility of having neutrino masses in supersymmetric theories is attempted here. Some of the recent works reviewed suggest Dirac masses, whereas others include Majorana masses as well. Side by side, it is shown how R-parity violating supersymmetry opens new avenues in the neutrino sector. Reference is also made to light sterile neutrinos, nearly degenerate neutrinos and neutrinos acquiring masses from hard supersymmetry breaking terms which are suppressed by the Planck scale. In several of the cases, it is pointed out how the models that give neutrino masses and mixing have independent motivations of their own, and can be tested in accelerator experiments.

39 ref

017465   Ma E (Physics Dep, California Univ, Riverside, California 92521 (USA)) : Neutrino mass matrix a la mode. Proc Indian Natn Sci Acad-Pt A 2004, 70(1), 233-8.

With the accumulation of many years of solar and atmospheric neutrino oscillation data, the approximate form of the 3 neutrino mixing matrix is now known. What is not known is the (presumably Majorana) neutrino mass matrix M_v itself. In this chapter, the approximate form of M_v is derived, leading to seven possible neutrino mass patterns: three have the normal hierarchy, two have the inverse hierarchy, and two have three nearly degenerate masses. The generalization of this to allow U_e3o with maximal CP violation is also discussed. A specific automatic realization of this M_v from radiative corrections of an underlying non-Abelian discrete A₄ symmetry in the context of softly broken supersymmetry is presented.

2 illus, 11 ref

017464   Krishnamurthy R;Chandorkar M S;Kalzunkar B G; Palsuledesai M R;Pathak J M;Gupta R (Zandu Foundation for Health Care, , Ambach (Village), Pardi (Tal.), Valsad (Dist)-396 145) : Agronomic manipulations for improving the productivity of shatavari (Asparagus racemosus) under irrigated and rainfeed conditions. J med aromatic Pl Sci 2004, 26(4), 740-5.

Tubers of shatavari (Asparagus racemosus) are extensively used in drug formulations as nutritive tonic, anabolic and galactagogue in the Indian system of medicine. As a field crop, this prickly perennial climber produces higher tuber yield at a closer spacings of 1.0 x 0.5 (20,000 plants/ha) and optimum tuber yield at moderate spacing of 1.0 x 1.0 (10,000 plants/ha) metres with the application of fertilizer dose 100 kg Nitrogen and 50 kg P₂O₅ per hectare). The crop needs 15 shallow irrigations to produce 3.7 - 5.2 tonnes of peeled tubers (dry) / ha in 19 months duration in sub-tropical regions at two spacings studied for two crop cycles from 1997 to 2000. As rain - fed crop under South Gujarat, Western India, it yields 1.8-3.1 tonnes of peeled tuber (dry) / ha in population densities of 10,000 - 20,000 plants / ha at 19 months age. It is economical to grow this medicinal crop on commercial scale for increasing the income by the growers.

4 illus, 2 tables, 7 ref

017463   Klapdor-Kleingrothaus H V;Sarkar U (Max Planck-Institut fur Kernphysik, , P O 10 39 80 D-69029 Heidelberg (Germany)) : Models of neutrino masses and mixings: implications of neutrinoless double beta decay. Proc Indian Natn Sci Acad-Pt A 2004, 70(1), 251-66.

One of the most important features of neutrinos is that they could be Majorana particles, which violates lepton number. This can be verified in neutrinoless double beta (Ovββ) decay experiments. An evidence for neutrinoless double beta decay has recently been announced, which has several very strong implications, some of which have been reviewed article. If the neutrinos are Majorana particles violating lepton number, then the Majorana masses could explain the baryon asymmetry of the universe. The solar, atmospheric and other laboratory experiments give is the mass squared difference between different neutrinos; only the Ovββ decay can give is the absolute masses. The latest result from Ovββ decay restricts the patterns of neutrino masses to very few choices, only the degenerate and the inverted hierarchical mass matrices are allowed for three generations of neutrinos. The allowed textures of the neutrino masses are also constrained.

10 illus, 48 ref

017462   Klapdor-Kleingrothaus H V (HEIDELBERG-MOSCOW and GENIUS Collaborations, Max-Planck-Institut for K, , P O 10 39 80, D-69029 Heidelberg (Germany)) : One year of evidence for neutrinoless double beta decay. Proc Indian Natn Sci Acad-Pt A 2004, 70(1), 95-122.

The experimental status in the search for neutrinoless double beta decay is reviewed, with emphasis on the first indication for neutrinoless double beta decay found in the HEIDELBERG-MOSCOW experiment, giving first evidence for lepton number violation and a Majorana nature of the neutrinos. Future perspectives of the field are briefly outlined.

21 illus, 9 tables, 133 ref

017461   Khan K A;Khan R A (Physics Dep, S P College, Srinagar (J&K) 190 001, Email: khurshid545@rediffmail.com) : Probabilistic cellular automata model for reaction diffusion systems. Indian J Chem-Sect A 2005, 44(2), 286-90.

Class of cellular automata (CA) for modeling reaction diffusion systems has been presented. The construction of the CA is general enough to be applicable to large class of reaction diffusion equations. The automata are based on running average procedure and on probabilistic table look up to implement diffusion reactions. The evolution of probabilistic CA simulates a spatially distributed process, given by a partial differential equation (PDE). The solutions are very isotropic despite the discreteness and the anisotropic nature of the CA. The adverse effects of discretization are overcome by the use of probabilistic rules. In order to obtain the assurance of the proposed method, the probabilistic CA approach for evolution of reaction diffusion process usually given bv PDE is proposed.

^ssc2 illus, 19 ref

017460   Joshipura A S (Theoretical Physics Group, Physical Research Laboratory, Navarangpura, Ahmedabad-380 009) : Introduction to models of neutrino masses and mixings. Proc Indian Natn Sci Acad-Pt A 2004, 70(1), 223-232.

An introduction has been given to models of neutrino masses for non-experts. Topics discussed are(i) different types of neutrino masses (ii) structure of neutrino masses and mixing needed to understand neutrino oscillation results (iii) mechanisms to generate neutrino masses in gauge theories and (iv) discussion of generic scenarios proposed to reliaze the required neutrino mass structures.

45 ref

017459   Indumathi D;Murthy M V N;Rajasekaran G (Institute of Mathematical Sciences, , Madras-600 113) : Neutrino physics. Proc Indian Natn Sci Acad-Pt A 2004, 70(1), 1-10.

2 illus, 1 tables, 15 ref

017458   Indumathi D (The Institute of Mathematical Sciences, , Chennai-600 113) : Physics from neutrino factories. Proc Indian Natn Sci Acad-Pt A 2004, 70(1), 79-87.

Reviews the physics potential of future neutrino factories, given the current status of knowledge about neutrino mixing parameters.

3 illus, 16 ref

017457   Goswami S (Harish-Chandra Research Institute, , Chhatnag Road, Jhusi, Allahabad-211 019) : Solar neutrino experiments. Proc Indian Natn Sci Acad-Pt A 2004, 70(1), 27-37.

Describes the seven experiments Homestake, Kamiokande, SAGE, GALLEX, Super-Kamiokande, GNO and SNO which have so far provided data on the measurement of the solar neutrino fluxes. The detection mechanism, the salient features of the detectors and the results of each experiment are presented. How the solar neutrino problem has evolved and become more focused with each experiment is summarized. The goals for the future experiments are outlined.

4 illus, 2 tables, 35 ref

017456   Dugad S R (Tata Institute of Fundamental Research, , Colaba, Mumbai-400 005) : Atmospheric neutrinos: probe beyond the standard model. Proc Indian Natn Sci Acad-Pt A 2004, 70(1), 39-51.

Atmospheric neutrinos are produced through interactions of cosmic rays in the atmosphere. They were first detected in 1965 and have been studied extensively since then. The detection of atmospheric neutrinos requires large-area detectors located deep underground. Observations from several experiments involving different techniques have finally led to conclusive evidence for neutrino oscillations. Neutrino physics relevant for atmospheric neutrino detection has been discussed first followed by the current knowledge on neutrino flux. Observations made by past and current experiments and their consequences for the Standard Model of particle physics have been reviewed. Future prospects for atmospheric neutrino observations have been summarissed.

8 illus, 3 tables, 28 ref

017455   Datar V M (Nuclear Physics Div, Bhabha Atomic Research Centre, Trombay, Mumbai-400 085) : Direct neutrino mass measurements. Proc Indian Natn Sci Acad-Pt A 2004, 70(1), 89-94.

The direct neutrino mass measurements for neutrinos of the three flavours are reviewed.

5 illus, 14 ref

017454   Choubey S;kar K (Physics and Astronomy Dep, Southampton Univ, Highfield, Southampton S017 1BJ (UK)) : Neutrinos from supernovae. Proc Indian Natn Sci Acad-Pt A 2004, 70(1), 123-33.

The effect of flavor oscillations on the neutrinos released during supernova explosion after core collapse is described. In some scenarios there is a large enhancement of the number of events compared to the no oscillation case. Various other features associated with supernova neutrinos are also discussed.

2 illus, 1 table, 54 ref

017453   Bhattacharya K;Pal P B (Saha Institute of Nuclear Physics, , 1/AF Bidhan-Nagar, Calcutta-700 064) : Neutrinos and magnetic fields. Proc Indian Natn Sci Acad-Pt A 2004, 70(1), 145-61.

Neutrinos have no electric charge, but a magnetic field can indirectly affect neutrino properties and interactions through its effect on charged particles. After a brief field-theoretic discussion of charged particles in magnetic fields, two broad kinds of magnetic field effects on neutrinos have been discussed. First, effects which come through virtual charged particles and alter neutrino properties. Second, effects which alter neutrino intractions through charged particles in the initial or final state. Some possible physical implications of these effects have been discussed.

5 illus, 74 ref

017452   Baba C V K (Nuclear Science Centre, , New Delhi-110 067) : Survey of experiments with reactor neutrinos. Proc Indian Natn Sci Acad-Pt A 2004, 70(1), 53-61.

Beginning with the very first detection of the electron anti-neutrino by Reines and Cowan, reactor neutrinos have played an important role in the understanding of the properties of the neutrinos. Summarises the recent experiments with reactor neutrinos which is now in a decisive phase.

7 illus, 3 tables, 22 ref

016348   Wisniak J (Chemical Engineering Dep, Ben-Gurion Univ of the Negev, Beer-Sheva, Israel-84105) : The nature of heat. Indian J chem Technol 2004, 11(4), 582-92.

The nature and effects of heat have intrigued philosophers and scientists since ancient times. Different theories were developed to explain the phenomena, and of these, the wave theory and the caloric theory were the ones that remained in force until the second half of the nineteenth century when overwhelming evidence led to the conclusion that heat was not a material substance, that the molecules of a gas were not stationary but could move in space, and that radiation and light were basically the same phenomena.

^iia36 ref

016347   Venugopalan K;Lakshmi N;Somayajulu D R S (Phys Dep, Mohanlal Sukhadia Univ, Udaipur-313 001, Email: nambakkat@yahoo.com) : Nuclear quadrupole interaction at F3-57 in semimetals Arsenic and Bismuth. Indian J Phys 2004, 78(9), 919-22.

Nuclear quadrupole interaction at iron impurities in arsenic and bismuth semimetals were measured using iron Mossbauer spectroscopy. From the quadrupole splitting values, the electric field gradient in arsenic is evaluated to be 8.42(22) x 10¹⁷ V/cm² and 3.87(12) x 10¹⁷ V/cm² for bismuth. The ratio of electronic contribution of electric field gradients to ionic contribution is found to be larger than that normally found in sp metals. In general, the electron contributions follow the trend set by the electron densities in these metals. However, the magnitudes of electric field gradient are not consistent with electron densities.

2 illus, 2 tables, 27 ref

016346   Vandana T;Rajendra Prasad K J (Chemistry Dep, Bharathiar Univ, Coimbatore-641 046) : Synthesis of quinolinocyclooct[b]indoles and diazocine in the same single step using friedlander's method. Indian J Heterocyclic Chem 2004, 13(4), 315-18.

Treatment of 1-oxo-1,2,3,4,5,6-hexahydrocyclooct[b] indoles,with o-amnioacetophenone in gl acetic acid afforded 7,8,9,10-tetrahydroquinolino [2',3':8,7] cyclooct[b]indoles. This reaction surprisingly yielded 12 methyl-6-(1'-propen-2'-ol)-dibenzo [b,f] [1,5]-diazocine as a side product. A plausible mechanism for the formation of the new product has been described.

1 scheme, 1 table, 8 ref

016345   Vaidya D J;Poria K (Phys Dep, South Gujarat Univ, Surat-395 007) : Systematic microhardness measurement on 5N pure single crystalline, non-crystalline and wire plate type bismuth samples. Indian J Phys 2004, 78(9), 1007-9.

Microhardness measurements were carried out on 5N pure crystalline, non-crystalline and wire plate type bismuth samples. The samples choosen have good cleavage or faceted surfaces. These samples were indented and average Vickers' microhardness number is calculated. The plots of microhardness variation with load were obtained and results were correlated with their anisotropy properties, slip planes and defect produced in it. The study of plastic deformation produced by point loading is of practical importance and the deformation produced in the study may be related to intrinsic microhardness values of bismuth.

4 illus, 1 table, 8 ref

016344   Thapa R K;Das G;Zadeng L;Bhattacharjee R (Condensed Matter Theory Res Group, Phys Dep, Pachhunga Univ Coll, Mizoram Univ, Aizawl-796 001) : Calculation of photofield emission from band stages using Kronig-Penney model and spatially varying photon field. Indian J Phys 2004, 78(9), 939-42.

A model photofield emission calculation is discussed which takes into consideration the band states and spatially dependent vector potential of the incident radiation. The initial state wavefunction is the one derived by using the Kronig-Penney potential model for the bulk and the surface region of metal.

1 illus, 17 ref

016343   Singh J P (Management Studies Dep, Indian Institute of Technol, Roorkee-247 667) : Supersymmetric quantum mechanics in quaternion space. Indian J Phys 2004, 78(9), 989-94.

Basic formulation of supersymmetry has been carried out in quaternionic Hilbert space in terms of quaternionic spinorial charges and the identification of extra imaginary components with the supertime anti-commuting variables and internal degrees of freedom.

8 ref

016342   Santhosh K P;Joseph A (Phys Dep, Coll Payyanur, Payyanur-670 327) : Exotic decay in <. Indian J Phys 2004, 78(9), 973-7.

Exotic decay of various Sm isotopes emitting ⁴He, ⁸Be, ¹²C, ²⁰Ne, ²⁴Mg, ²⁸Si, ²⁹Si and ³²S clusters were studied taking the potential barrier as the sum of Coulomb and proximity potential. The predicted half life time values for most of these clusters are well within the present upper limit for measurements and our values lie close to those of CYEM and ASAFM. It is found that ²⁴Mg emission from ¹²⁴Sm and ²⁸Si from ¹³⁰Sm are most favourable for measurements with lowest half life time ( T_1/2 ≤ 10¹⁷ s). Lowest half life time for ²⁴Mg from ¹²⁴Sm stress the role of doubly magic ¹⁰⁰Sn daughter in exotic decay. Nuclear structure effects and shell effects are evident from the variation in slope and intercept of the Geiger Nuttall plots for different clusters. It is found that the presence of neutron excess in the parent nuclei will slow down the exotic decay process.

6 illus, 2 tables, 25 ref

016341   Rashid M H;Bhandari R K (Variable Energy Cyclotron Centre, , Sector-1, Block-AF, Bidhan Nagar, Kolkata-700 064) : Sufficient cusp field generated by permanent magnet for compact ECR ion source. Indian J Phys 2004, 78(9), 955-9.

Cusp modified minimum-B field configuration has been used earlier for designing electron cyclotron resonance ion source (ECRIS) for 2.45 GHz μ-wave (microwave) frequency but the usage was very rare. Few ECRIS of this type were tested for <62>2.45 GHz using conventional minimum-B configuration comprising the axial field and radial multipole field created by permanent magnets. Some people used permanent magnet also to generate conventional field or cusp field configuration for such source. In the note, it has been attempted to understand the problems of the old cusp field ECRIS. They are mitigated using available permanent magnet having very high remanence and coercivity and negatively-biased metal ring and disk in the mid-plane and at the injection end for designing and constructing a compact and very cost-effective ECRIS of the future.

3 illus, 14 ref

016340   Rajkhowa R;Sarma J K (Phys Dep, Tezpur Univ, Napaam, Tezpur-784 028) : Particular solution of DGLAP evolution equation in next-to-leading order and structure functions at low-x. Indian J Phys 2004, 78(9), 979-87.

Authors present particular solutions of singlet and non-singlet Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) evolution equations in next-to-leading order (NLO) at low-x. Authors obtain t-evolutions of deuteron, proton, neutron and difference and ratio of proton and neutron structure functions at low-x from DGLAP evolution equations. The results of t-evolutions are compared with HERA and NMC low-x and low-Q² data and with those of leading order (LO) solutions of DGLAP evolution equations. Authors also compare the result of t-evolution of proton structure function with a recent global parameterization.

4 illus, 19 ref

016339   Rajamanickam N;Prabhu A S;Raja V;Kumar K B; Karthikeyan B;Bagare S P (Physics Research Centre, V.H.N.S.N College, Virudhunagar-626 001) : Transition probability parameters for certain band systems of TlCl and TlF molecules. Asian J Spectrosc 2004, 8(1), 37-41.

Franck-Condon factors and r-centroids, which are very closely related to transition probabilities and are a theoretical measure of the relative intensity distribution, have been evaluated by a reliable numerical integration procedure for the bands of A ³Π₀ - X ¹Σ⁺ system of TlCl and A ³Π₀ - X ¹Σ⁺, B ³Π₀ - X ¹Σ⁺ systems of TlF.

3 tables, 7 ref

016338   Modi B P;Mathai A J;Patel K D;Pathak V M; Srivastava R (Phys Dep, Sardar Patel Univ, Vallabh Vidyanagar-388 120) : Charge transport through In-pSi (100) Schottky barrier. Indian J Phys 2004, 78(9), 995-7.

Schottky barrier devices on p-type silicon were fabricated using indium as contacting metal. Barrier heights and ideality factors of the prepared devices were evaluated by analyzing the V-I data at room temperature. The results have been discussed for the type of charge transport. They have also been compared with expected values on some basic models for SBHs.

2 illus, 1 table, 8 ref