IOSR-JAP   Volume-8 ~ Issue-6 ~ Nov-Dec 2016

ABSTRACT: In this paper, we study the band structures of Boron compounds (BX, X=N, P, As, Sb) under III-V semiconductor compounds. Our calculations were performed using a Generalized Gradient Approximation (GGA) and the modified Becke-Johnson potential (mBJ) within the Full Potential Linearized Augmented Plane Wave (FP-LAPW) method. We have compared our results calculated by GGA and mBJ and we found that the mBJ approximation gives better results in semiconductor compounds compared to GGA. We also obtained the results on the band structures with the inclusion of Spin-Orbit Interaction(SOI) on both approximations and also compared the results.............

Keywords: FP-LAPW, GGA, mBJ, spin-orbit interaction, band structure, splitting energy, pnictides.

[1]. N. E.Christensen and I.Gorczyca, Optical and Structural Properties of III-V Nitrides under Pressure, Phys. Rev. B 50, 1994, 4397.
[2]. B.Abbar, B. Bouhafs, H. Aourag, G. Nouet and P. Ruterana, First-Principles Calculations of Optical Properties of AlN, GaN, and InN Compounds under Hydrostatic Pressure, Phys. Stat. Sol. (b) 228, 2001, 457.
[3]. I. Gorczyca and N. E.Christensen, Band Structure and High-Pressure Phase Transition in GaN, AlN, InN and BN, Physica B 185, 1993, 410.
[4]. B.T. Liou, C. Liu and Y.K. Kuo, Investigation of Material Properties for Zincblende AlGaN Alloys Applied in UV LEDs, Proc. of SPIE, 2007, 6669.
[5]. C. Stampel and C. G. Van de Walle, Density-Functional Calculations for III-V Nitrides Using the Local-Density Approximation and the Generalized Gradient Approximation, Phys. Rev. B 59, 1999, 5521.

ABSTRACT: The madden Julian oscillation (MJO) is defined as propagation of rainfall from Indian ocean to west pacific ocean with an average velocity of 5m/s. the purpose of this paper is to study the impact of mjo on basic parameters of atmosphere like, temperature, wind velocity, wind direction and pressure. To study this, the Radiosonde data of Jakarta (A low latitude station from which MJO is passing) for the years 2014 and 2015 is collected. Finally some variation is noticed in the temperature, wind velocity, wind direction and pressure. This study is helpful for forecasting and understands the dynamics of atmosphere

Keywords: Madden Julian Oscillation, Pressure, Temperature, Meridional Wind & Zonal Wind

[1] Hartmann D L & Michelsen M L, Intras easonal periodicities in Indian rainfall, J Atmos Sci (USA), 46 (1989) pp 2838–2862
[2] Madden R A & Julian P, Detection of a 40–50 day oscillation in the zonal wind in the tropical pacific, J Atmos Sci (USA), 28 (1971)
pp 702–708
[3] Hendon Harry H, Zhabg C & Glick J D, Inter-annual variation of the Madden – Julian Oscillation during austral summer, J Clim
(USA), 12 (1999) pp 2538–2550.
[4] Hartmann D L & Michelsen M L, Intras easonal periodicities in Indian rainfall, J Atmos Sci (USA), 46 (1989) pp 2838–2862.
[5] Sikka D R & Gadgil S, On the maximum cloud zone and the ITCZ over Indian longitudes during the south west monsoon, Mon
Weather Rev (USA), 108 (1980) pp 1840-1853, doi: 10.1175/1520-0493(1980).

ABSTRACT: In this work we report the study of optical properties for titanium dioxide, The samples all showed high transmission in the UV region with transmission edges in the blue region of the electromagnetic spectrum. Photo activation of 𝑇𝑖𝑂2 in this region causes transition from the ground to excited state, also we can found The relation between the absorption coefficient (α) and the incident photon energy , and found rapidly decrease in absorption coefficient value .until to arrive to peak, then it reduce from high temperature because of less absorption in high energies from energy gap Transition decreasing due to transmission decreasing

Keywords: Beer Lamberts, Energy band gap, Optical Properties

[1] "Market Study: Titanium Dioxide". Ceresana. Retrieved 21 May 2013.

[2] Winkler, Jochen (2003). Titanium Dioxide. Hannover: Vincentz Network. pp. 5. ISBN 3-87870-148-9.

[3] Koleske, J. V. (1995). Paint and Coating Testing Manual. ASTM International. p. 232. ISBN 978-0-8031-2060-0.

[4] Koleske, J. V. (1995). Paint and Coating Testing Manual. ASTM International. p. 229. ISBN 978-0-8031-2060-0.

[5] Pearlescence with Iriodin. pearl-effect.com

ABSTRACT: Amplitude modulation as well as demodulation of an electromagnetic wave in transversely magnetized quantum plasma with strain dependent dielectric constant is analyzed in different wave number regions over a wide range of carrier cyclotron frequency. The consideration of quantum effects in modulation and demodulation is of prime importance for the adding of new dimensions in acousto-electric magnetized semiconductor plasma. It is found that quantum effects modify the amplitude modulation and demodulation processes effectively. Numerical estimates are made for n-BaTiO3 crystal at 77K duly shined by a pulsed 10.6 μm CO2 laser .Complete absorption of the wave takes place in all the possible wavelength regimes when the cyclotron frequency ωc becomes nearly equal to ω0.

Keywords: Acoustoelectric effect, Strain dependent dielectric constant, Quantum effects.

[1]. F. Hass, L.G. Garcia, J. Goedert and G. Manfredi, Quantum ion-acoustic wave, 2003, Phys. Plasmas, 10(10), 2003, 3858-3866.
[2]. P. K. Shukla and S. Ali, Dust acoustic waves in quantum plasmas Phys. Plasmas, 12, 2005, 114502-03.
[3]. A.P. Mishra and A.R Chowdhury, Modulation of dust acoustic waves with a quantum correction, Phys. Plasmas 13, 2006, 072305-
12.
[4]. R. Sanghvi and S. Ghosh, Amplitude Modulation and Demodulation of Electromagnetic Waves in Magnetized with Strain-
Dependent Dielectric Constant, Material, Phys. Stat. Sol. 118, 1990, 235.
[5]. Aartee Sharma, Nilesh Nimje, N. Yadav and S. Ghosh, Effect of Density Gradient on Longitudinal Phonon-Plasmon

ABSTRACT: The aim of this study is to analyze the drought characteristics and draw a spatial pattern maps for drought by using the ordinary kriging interpolating method within a GIS environment. The Standardized Precipitation Index (SPI) was used to analyze the drought, based on the historical data for ten meteorological stations during the years from 1980 to 2011in the Iraq region. The result shows that the maximum severity of drought (Smax) value was identified during the periods 2007-2011 for most of the stations and the highest value of average severity of drought (Savg) was found in the north (central) region of Iraq for SPI 9 month (SPI 12 month), respectively. The results showed that the 1999, 2008 and 2009 years were the worst drought years have passed in all parts of Iraq at SPI 9, and 12-month time scale.

Keywords: Standardized Precipitation Index (SPI); Drought; Iraq.

[1] D. C. Edwards, and T. B. McKee. Characteristics of 20th Century Drought in the United States at Multiple Time Scales. Atmospheric Science Paper. 1997, 634.
[2] W.C. Palmer. Meteorological drought. Vol. 30. Washington, DC: US Department of Commerce, Weather Bureau, 1965.
[3] W.J. Gibbs,and J.V. Maher. Rainfall Deciles as Drought Indicators, Bureau of Meteorology bulletin No. 48. Commonwealth of Australia: Melbourne; 1967,29.
[4] T.J. Brown, and R.S. Kangas. Characteristics of US drought and pluvials from a high-resolution spatial dataset. International Journal of Climatology, 2007, 27,1303e1325.
[5] T.B. McKee, N.J. Doeskin, and J. Kleist. The relationship of drought frequency and duration to time scales. In: 8th Conference on Applied Climatology. American Meteorological Society, 1997, pp. 179e184.

ABSTRACT: The term fusion barrier distribution provides a clear method to test the effect of nuclear structure on the behavior of nuclear matter and dynamics of nuclear reactions, especially for energies where penetrability effects are considered. It presents an unexpected enhancement, as compared with conventional models of tunneling through a one-dimensional penetration model. The quantum mechanical barrier penetration effects play a central role, where the fusion cross section has been vanished suddenly as the bombarding energy becomes less than the barrier.............

Keywords: Barrier distribution, barrier height, excitation function , penetrability

[1]. E. Piasecki et al , acta phys. Pol. B33 , 397,(2002)
[2]. L. C. Vaz, et al, Phys. Rep. 69, 373,(1981)
[3]. L. C. Vaz and J. M. Alexander, Phys. Rev. C 18 , 2152, (1978)
[4]. R. Bass , Nucl.Phys. ,A231 ,45, (1974)
[5]. H. J. Krappe, et al, Phys .Rev. C 20 , 992 ,(1979)
[6]. H. Esbensen et al., Phys. Rev. C 40 , 2046 , (1989)

ABSTRACT: Fine powders of Y3+ doped Ni1-X Cdx Yy Fe2-YO4 (where x = 0, 0.2, 0.4, 0.6 and y = 0, 0.075) spinel nanoferrite were prepared using a sol-gel autocombustion techniques and sintered at 400 oC for duration of 2 hrs. The analysis of XRD patterns revealed the formation of single phase cubic spinel structure. The lattice parameter and crystallite size decreases with increase in Y3+ concentration and average grain size was found to be between 12.5 to 34.8 nm. The dielectric properties have been studied as a function of frequency (100 Hz to 5 MHz) at room temperature using LCR meter and shown the normal dielectric behaviour. The value of ac conductivity increases with increase in frequency for all the compositions. TG-DTA analysis of the auto combusted ferrites was carried out with a heating rate of 10 ℃/min in air. These results may be applicable for promising area such as high frequency electrical devices.

Keywords: Nanoferrite; Sol-gel autocombustion method; Optical properties; Dielectric constant; Thermal properties

[1]. Chand J., Kumar Gagan, Kumar P., Sharma S. K., Knobel M., and Singh M. (2011). Effect of Gd3+ doping on magnetic, electric and dielectric properties of MgGdxFe2−xO4 ferrites processed by solid state reaction technique. J. Alloys and Compds., 509: 9638-9644.
[2]. Lakshmi M., Vijaya Kumar K. and Thyagarajan K. (2016). Study of the Dielectric Behaviour of Cr-Doped Zinc Nano Ferrites Synthesized by Sol-Gel Method. Advances in Materials Physics and Chemistry, 6: 141-148.
[3]. http://dx.doi.org/10.4236/ampc.2016.66015
[4]. Srivastava M., Chaubey S. and Ojha A.K. (2009). Investigation on Size Dependent Structural and Magnetic Behavior of Nickel Ferrite Nanoparticles Prepared by Sol-Gel and Hydrothermal Methods. Materials Chemistry and Physics, 118: 174-180. http://dx.doi.org/10.1016/j.matchemphys.2009.07.023
[5]. Kharabe R.G., Devan R.S., Kanamadi C.M. and Chougule B.K. (2006). Dielectric Properties of Mixed Li-Ni-Cd Ferrites. Smart Materials and Structures, 15: 36-39. http://dx.doi.org/10.1088/0964-1726/15/2/N02

ABSTRACT: The isomorphous alkaline earth nitrates Ba(NO3)2 and Pb(NO3)2 are materials with cubic structure. Mixed crystals of BaxPb1-x(NO3)2 were grown from solution by slow evaporation. Single phase mixed crystals were formed. The capability of mixing the materials and Vegard`s law are tested. Powder diffractometer was employed to record their X-ray patterns. The non-linear dependence of composition with positive and negative deviations from linearity is observed in mean Debye Waller factor and Debye temperatures respectively. Melting temperatures measured also show a non-linear dependence with negative deviations from linearity.

Keywords: Vegard`s law, Debye Waller factor, Debye temperature, Bragg reflections, lattice constants, melting temperatures.

[1]. Bon, A. M., Benoit, F. C. and Bernard, O. (1976a). Phys. Stat. Sol. (b), 78, 67.
[2]. Bon, A. M., Benoit, F. C. and Giorano, J. (1976b). Phys. Stat. Sol. (b), 78, 453.
[3]. Brooker, M. H., Irish, D. E. and Boyd, G. E. (1970). J. Chem. Phys. 53, 1083.
[4]. Santos. R. A. Tang. T., Chien. W. J., Kwan. S. and Harbison. G. S. (1990). J. Chem. Phys. 94. 2717.
[5]. Couture, L., Mathieu, J. P. and Ann. (1948) Phys. (NY). 3,521.

ABSTRACT: On the basis of the thermodynamic theory of transfer and transformation of all forms of energy and of the principle of mass-energy equivalence is established a more general law of gravity, according to which in the non-baryonic matter there is a gravitational force of attraction and repulsion. This theory predicts the existence of gravitational equilibrium, strong and weak gravity, as well as the presence of a huge free gravitational energy re-serves with the possibility of its use. This makes unnecessary the introduction of dark energy as a hypothetical me-dium, causing the accelerated expansion of the Universe.............

Keywords: Universe, baryonic and non-baryonic matter, theory and consequences, attraction and repulsive force, gravitational equilibrium, strong and weak gravity, data of observations.

[1]. Clowe D. et al. 2006, A Direct Empirical Proof of the Existence of Dark Matter.) // The Astrophysical Journal Letters. Vol. 648, no. 2. — P. L109–L113.

[2]. Riordan M. 2012, Shadows of Creation: Dark Matter and the Structure of the Universe. — W H Freeman & Co (Sd). — ISBN 0-7167-2157-0.

[3]. Perlmutter S. 2012, Nobel Lecture: Measuring the acceleration of the cosmic expansion using supernovae. // Rev. Mod. Phys. Vol. 84. P. 1127—1149.

[4]. Ade P. A. R. et al. 2013, Planck 2013 results. I. Overview of products and scientific results. //Astronomy and Astrophysics, 1303: 5062

[5]. Etkin V. 2011. Energodynamics (Thermodynamic Fundamentals of Synergetics). — New York, 480 p.

ABSTRACT: A single crystal of Zirconyl oxy urea thiourea has been grown successfully from its aqueous solution. The grown crystals have been subjected to X-ray diffraction studies to identify the morphology and structure. The TGA-DTA studies showed the thermal properties of the crystals. The functional group of the grown crystals was found by UV - Visible double beam spectra, FT-IR analysis, NMR and XRD studies.

Keywords: Urea, Thiourea, Zirconium Oxy-chloride, Zirconyl oxy urea thiourea (ZrOTU), X-Ray diffraction, UV-Vis, FT-IR, NMR, TGA, NLO and micro hardness.

[1]. Saha J K and Podder J, 2011. Crystallization of zinc sulphate single crystals and its structural, thermal and optical characterization. J. of Bang. Aca. Of Sci. 35: 203-210.
[2]. Viruthagiri G, Praveen P, Mugundan S and Anbuvannan M, 2013. Growth and Characterization of L-Histidine Doped Thiourea Single Crystals by Slow Evaporation method. Ind. J. of Adv. in Chem. Sci. 1: 193-200.
[3]. Sundararajan R S, Senthilkumar M and Ramachandraraja C, 2013. Growth and Characterization of Bisthiourea Nickel Bromide-New Semi organic Nonlinear Optical Crystal. J. of Crys. Pro. and Tech. 3: 56-59.
[4]. Gunasekaran S, Anand G, Arun Balaji R, Dhanalakshmi J and Kumaresan S, 2010. Crystal growth and comparison of vibrational and thermal properties of semi-organic nonlinear optical materials. J. of Phy. 75: 683-690.
[5]. Thomas Joseph Prakash J and Ruby Nirmala L, 2011, Synthesis, spectral and thermal properties of bisthiourea zinc acetate (BTZA) single crystals. Int. J. of Comp. App., 6: 0975-8887.

ABSTRACT: Lead Titanate (PbTiO3) sample was prepared using Solid State reaction method. The structural analysis done using X-ray diffraction (XRD) at room temperature. The crystal structure has been refined using FULLPROF program by employing Rietveld analysis. The direct lattice parameter found out to be a = b = 3.9015 Å and c = 4.1280 Å. The crystal system is tetragonal with space group found out to be P4mm and the ATZ value is 303.078. The micro structural analysis done using Scanning Electron Microscope (SEM).

Keywords: Lead Titanate, XRD, Rietveld analysis, SEM

[1]. F. Jona and G. Shirane, Ferroelectric Crystals, MacMillan, New Yor k, NY, US A, 1962 .
[2]. R. Migoni, H. Bilz, and D. Bauerle, "Origin of raman scattering and ferroelectricity in oxidic perovskites," Physical Review Letters, vol. 37, no. 17, pp. 1155–1158, 1976.
[3]. L. E. Cross, "Dielectric, piezoelectric and ferroelectric components," The Bulletin of the American Ceramic Society,vol.63, pp. 586–590, 1984.
[4]. K. Sasazawa, K. Oshima, and N. Yamaoka, "Surface potential decay and residual voltage measurements in highly elongated polyethylene," Japanese Journal of Applied Physics,vol.26, pp. L65–L67, 1987.
[5]. T. R. Shrout and A. Halliyal, "Preparation of lead-based ferroelectric relaxors for capacitors," American Ceramic Society Bulletin,vol.66,pp.704–711,1987.