IOSR-JAP   Volume-9 ~ Issue-6 ~ Nov-Dec 2017

ABSTRACT: Intrinsic Fermi level and charged intrinsic defect density in doped semiconductors has been calculated by a new method proposed earlier, that utilizes the conduction band offset in a semiconductor/insulator interface of an MIS device. This paper generates new and improved data to corroborate the new method. The method is now found to be applicable to all semiconductors, provided the band offsets are determined correctly. Very high and very low values of defect densities can be obtained by this new method that is not possible by the existing experimental techniques like DLTS, EPR, and others. The article also gives a new equation of the intrinsic Fermi level in semiconductors with an added term due to the density of charged intrinsic defects...........

[1]. A. Alkauskas, M.D. McCluskey, and C.G. Van de Walle, "Tutorial: Defects in semiconductors- Combining experiment and theory", J. Appl. Phys., vol. 119, 181101, 2016.
[2]. R.K. Chanana, "N-Channel silicon MOSFET as a device to characterize MIS structures by the BOEMDET technique", IOSR-J. Appl. Phys., vol. 7, Issue-4, pp.17-25, Jul-Aug, 2015.
[3]. Y.C. Yeo, T.J. King and C. Hu, "Metal-dielectric band alignment and its implication for metal gate complementary metal-oxide-semiconductor technology", J. Appl. Phys., vol.92, pp.7266-7271, 2002.
[4]. E.G. Seebauer, M.C. Kratzer, "Fundamentals of defect ionization and transport" in Charged Semiconductor defects-Structure, thermodynamics and diffusion, Springer, 2009, pp. 5-34.
[5]. E. Janzen, N.T. Son, B. Magnusson, A. Ellison, " Intrinsic defects in high-purity SiC", Microelectronic Engineering, vol.83, pp. 130-134, 2006.

ABSTRACT: Nanomaterial's play a pivotal role in physical, spinel ferrites are useful magnetic materials because of their low cost and high electromagnetic performance over a wide frequency range as compared to the pure metals. In this research we have Preparedzinc-copper ferrite (ZnOX CuO1-X Fe2O3 ) nanoparticles by using powder metallurgy route,where x = ( 0.2).A mold is designed in diameter (1cm) with a hight of (3cm), and the weight of the sample is (1.3 g), and ferrite parts are formed by pressingwith a pressure of (700) psi,the sintering temperature of (1000 °C) for four hours .X-ray Diffraction (XRD) to find the lattice parameters and crystallite size of the sintered ferrite specimensconfirmed the formation of tetragonal single phase zinc-copper ferrite nanoparticles. The particle size calculations were done...........

[1]. A. Animesh, C. Upadhyay and H.C. Verma, Physics Letters A, 311(2003)410.
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[3]. C. Barry; N. Grant "Ceramic materials: science and engineering"Springer,(2007).
[4]. A. Hernandezbattez , R. Gonzalez, J. Viesca, J. Fernandez, J. Diazfernandez, A. MacHado, R. Chou, J. Riba, "CuO, ZrO2 and ZnO nanoparticles as antiwear additive in oil lubricants" Wear ,Vol. 265, P.422-428, (2008).
[5]. Zhong J, Kitai AH, Mascher P and Puff W, "The influence of processing conditions on point defects and luminescence centers in ZnO", J. Electrochem. Soc. 140,3644-3649 (1993).

ABSTRACT: In present work the series of aluminium and cobalt doped lithium hexaferrites with chemical compositional formula Li0.5Fe0.5+xAl12-2X CoX O19 ( where x=2,3,4,5 and 6) was synthesized using perfect stoichiometric mixtures of oxide by standard ceramic solid state reaction method at 12000C for 120 hrs. The chemical phase analysis of all compounds has been checked by X-ray powder diffraction (XRD) which confirmed the formation of the ferrite structure. It shows all are hexagonal magnetoplumbite (M -type) structure without traces of uncertainly ambiguous reflection having unit cell dimension 'a' parameter in the range from 5.6953 A.U to 5.8594 A.U and 'c' parameter varies between 21.2626 A.U to 22.3234 A.U pertaining the space group P63/mmc (No.194). The mass density of the ferrites were found linearly varies and depends upon the mass and volume of sample. The magnetic properties of polycrystalline sample are studied by using the external applied magnetic field up to 10 KOe and it shows the moderate values of coercivity (Hc), saturation magnetization (Ms) and retentivity (Mr).This measurements were carried out on a vibrating sample magnetometer (VSM).

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ABSTRACT: We study the optimal Tarzan jump from massive rigid rod. Since a part of the initial potential energy of the rod can be changed to the kinetic energy of Tarzan, he can jump further than that from massless rope.We find that his flying distance can be arbitrarily large depending on mass and density distribution of the rod. This study will be suitable for students of introductory calculus-based physics class.

[1]. K. P. Trout and C. A. Gaston, Active-learning physics experiments using the Tarzan Swing,Physics Teacher, vol. 39(3), pp. 160-163, 2001.
[2]. H. Shima, How far can Tarzan jump?European Journal of Physics, vol. 33, pp. 1687-1693, 2012.
[3]. M. Rave and M. Sayers, Tarzan's Dilemma: A Challenging Problem for Introductory Physics Students,Physics Teacher, vol. 51(8), pp.456-458, 2013.
[4]. C. E. Mungan, Analytically solving Tarzan's Dilemma, Physics Teacher, vol. 52, pp. 6, 2014.
[5]. Y. Kajiyama, Tarzan's Dilemma for Elliptic and Cycloidal Motion, Journal of Basic and Applied Physics, Vol. 5 Iss. 1, PP. 1-7, 2016.

ABSTRACT: The research study represents fabrication and characterizations of CdSe nanorod based dye-sensitized solar cells (DSSCs). In this work natural dyes are used as a photosensitizer to enhance the efficiency of the as prepared solar cells. It was extracted from Clitoria ternatea, Hibiscus rosa-sinensis and Ixora chinensis petals in a cost effective way. A comparative study is made to find the effect of optical absorption properties of different natural dyes on the CdSe nanorod-based DSSCs. The fill factor (FF), efficiency (η), short-circuit current density (Jsc), open-circuit voltage (Voc) of the DSSCs are determined from current-voltage measurements and power –voltage characteristics. The incident photon-to-current efficiencies (IPCE) of the DSSCs are also reported.

[1]. K. I. Bahadur, N. J. Jyoti, M.P. Kumar, C. Suman, Dye-Sensitized Solar cell using extract of Punica Granatum L. Pomegranate (Bedana) as a Natural Sensitizer. Research of J. Chem. Sci 2 : 2012, 81–83.
[2]. C. Bayron et al Natural dyes as sensitizers to increase the efficiency in sensitized solar cells. Journal of Physics: Conseries 720, 2016,doi : 10.1088/1742-6596/720/1/012030.
[3]. R. Buscaino, C. Baiocchi , C. Barolo Inorganica.Chimica.Acta. 361, 2008, 798–805.
[4]. H, Chang et al Characterization of Natural Dye Extracted from Wormwood and Purple Cabbage for Dye-Sensitized Solar Cells. International Journal of Photoenergy, 2013, dx.doi.org/10.1155/2013/159502.
[5]. Y.Chiba , A.Islam , Y. Watanabe , R. Komiya , N. Koide , L. Y Han Japanese.J.Appl.Phys. 45, 2006, 638–640..

ABSTRACT: In this work, a high-performance photocatalyst Ag: ZnO nanowires (Ag: ZnO NWs) was synthesized via a chemical bath deposition method for the photo degradation of organic dye under UV light irradiation.The structure, morphology, and photocatalytic activity of as synthesized sample were determined using X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-visible absorption spectroscopy (UV-vis spectrum). The XRD result showed that this catalyst was composed of metallic Ag and ZnO. The photocatalytic activity of the as synthesized samples were evaluated by the degradation of methyl orange (MO) in aqueous solution under UV light irradiation. Ag: ZnO NWs show better crystallinity, high specific area, and an increased area of contact. Hence they are better photocatalysts than undoped ZnO NWs. The Ag: ZnO NWs has influenced the photocatalytic activity of nanocrystalline........

[1] O. Ozdemir, B. Armagan, M. Turan, M.S. Celik, Comparison of the adsorptioncharacteristics of azo-reactive dyes on mezoporous minerals,Dyes Pigments,62(1), 2004, 49–60.
[2] S. Wang, H. Li, S. Xie, S. Liu, L. Xu, Physical and chemical regeneration of zeoliticadsorbents for dye removal in wastewater treatment,Chemosphere,65(1),2006, 82–87.
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[4] K. Hashimoto, H. Irie, A. Fujishima, TiO2 Photocatalysis: A Historical Overview and Future Prospects, Japanese Journal Applied Physics, 44 (12),2005, 8269–8285.
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ABSTRACT:This study aims to examine the mobility of uranium and its isotopes and daughters during the acid leaching. In the same context the study of the daughter / parent ratios in the three phases, original sample, leach liquor and residue will gave a complete picture about the behavior during weathering and alterations of these rocks. Five samples of different rock types were collected and prepared for various analyses. Wet chemical analyses were carried out for major oxides and trace elements. Natural radionuclides were measured by HPGe detector in original samples, pregnant solution and residuals. The results showed that the relation between the sum of activities of 238U in both pregnant solutions and residuals.......

[1]. Andersen M. B, Erel Y and Bourdon B., (2009): "Experimental Evidence for 234U-238U Fractionation During Granite Weathering with Implications for 234U/238U in Natural Waters", Geochimica et Cosmochimica Acta, V. 73, PP. 4124-4141.
[2]. Anjos, R.M.; Veiga, R.; Soares, T.; Santos, A.M.A.; Aguiar J.G.; Frascá, M.H.B.O.; Brage, J.A.P.; Uzêda, D.; Mangia, L.; Facure, A.; Mosquera, B.; Carvalho, C. and Gomes, P.R.S., (2005): " Natural Radionuclide Distribution in Brazilian Commercial Granites", Radiation Measurements, V.39, PP.245-253.
[3]. Bourdon B, Bureau S, Andersen M. B, Pili E and Hubert A., (2009): " Weasthering Rates from Top to Bottom in a Carbonate Environment", Chem. Geol, Vol. 258(3-4), PP. 275-287.
[4]. Depaolo D. J, Maher K, Christensen J. N and Mcmanus J., (2006): "Sediment Transport Time Measured with U-series Isotopes: Results from ODP North Atlantic Drift Site 984", Earth and Planetary Science, V. 74, PP. 47-53.
[5]. El Aassy I. E., El Feky M. G., El Kasaby M. A., Ibrahim E. M., Sewefi S. and Attia R. M., (2017): "Behavior of Radionuclides during Acidic Leaching Processes of Different Rock Materials, Allouga Locality, Southwestern Sinai, Egypt", International Journal of Scientific & Engineering Research, V. 8, Issue 1, ISSN 2229-5518

ABSTRACT: Nano materials involve research and technology development at the 1nm -100nm range. It creates and uses structures that have novel properties because of their small size. It builds on the ability to control or manipulate at the atomic level. Nano materials are been applied to almost every field imaginable, including electronics, magnetic, optics, information technology, materials development and biomedicine. Because of their small size, nano scale devices can readily interact with molecules on both surface and inside cells. It's a review on nano materials: as to what are nano materials, how are they formed, what is significance of nanoscale, how the properties of materials changes as it enters nanoscale range. What are the tools to prepare nanostructure and preparation of nanomaterials is briefly discussed. To explain properties and applications of nanomaterial's examples like carbon nanotubes and buckyballs are considered. To explain usefulness of nanomaterials in everyday life some applications are discussed.

[1]. Nanotechnology: Principle and Practice, Sulabha K. Kulkarni,2007
[2]. Nano materials: An introduction to synthesis, Properties and Applications, Dreter Vollath
[3]. Springer Handbook of Nanotechnology, Bharat Bhushan,2004
[4]. Nanostructures and Nano materials , Guozhong Cao,2004
[5]. Nano materials, Nanotechnologies and Design, Michael F,Ashly,2009

ABSTRACT: The two temperature models are reported to investigate the results of intensity And temperature depending upon pulse the pulse interaction .The propagation of ultra-short laser pulse depends upon the dielectric and the electron and electron collision frequency. The basic results are reported in terms of intensity and temperature profile .This results provides a better understanding of the amplitude modulation and demodulation of the high intensity laser wave incorporating the carrier heating (CH) effect in opto-acosutic semiconducting plasma. The carrier effects add a new dimension to investigate the results of ultra-laser pulse propagation in high strain dielectric material under a different different wave number regime over a wide range of cyclotron frequency .This result provides a...........

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ABSTRACT: In this paper the current understanding of the electron-electron scattering contribution to the temperature dependent part of the thermal resistivity (Wee) of the alkali metals is reviewed. These systems are modelled by a uniform electron gas, with the electron mass modified to take account of bandstructure effects and the electron-electron interaction modified to take account of the screening of this interaction by the core electrons. A simple approximation for the scattering function based on the Landau parameters has been used. By Comparing predicted values of Wee with experiment in the alkali metals, where the model is most appropriate, we conclude that the approximate scattering function is sufficiently accurate. Predicted values of Wee in most simple metals are mush smaller than in the alkalis. Estimates of the contribution from electron-electron scattering to the electrical resistivity based on the same scattering function have also been calculated for the akali metals.

Key words: Band structure, core electrons, electrons gas, Landau parameter, scattering function, thermal resistivity.

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