IOSR-JAP   Volume-5 ~ Issue-1 ~ Nov–Dec 2013

Abstract: Thermal oxidation of copper has been restudied to control the formation of photovoltaic active cupric oxide (CuO) phase against the cuprous oxide (Cu2O) phase. It has been established that the thermal oxidation of copper is governed by the outward lattice diffusion and grain boundary diffusion of copper ions at the interface. The lattice diffusion favors the formation of Cu2O phase whereas grain boundary diffusion favors the formation of CuO phase. In the present work, a fine copper powder is taken as starting material for thermal oxidation to increase the grain boundary diffusion and to study its on phase formation. Further, to suppress the grain boundary diffusion the starting material is chemically passivated with diethylenetriamine and olelamine to chameically passivated the surface defects. Thermal oxidation of these pre-treated materials is carried out in open air at temperature 500 oC and 700 oC to study the phase formation. The resulting materials are characterized by x-ray diffraction and scanning electron microscopy. These studies clearly confirm that grain boundary diffusion or defect mediated diffusion due to small particle size and more surface atoms of copper favor the formation of CuO at low temperature in case of pure copper, whereas the chemical passivation and high temperature heating favours the formation of Cu2O phase and hence the resulting material is biphasic. Hence, the present study is useful information in controlling the phase formation of copper oxide to obtain more photoactive material that is CuO.

Keywords: Thermal Oxidation, copper, lattice diffusion, grain boundary diffusion, CuO and CuO2 phases.

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[6] Z. Hai, C. Zhu, J.Huang , H.Liu , and J. Chen, Controllable Synthesis of CuO Nanowires and Cu2O Crystals with Shape Evolution viaγ-Irradiation, Inorg. Chem. , 49,2010, 7217–7219.

[7] S. Manna , K.Das , and S.K. De, Template-Free Synthesis of Mesoporous CuO Dandelion Structures For Optoelectronic Applications, Applied materials and interfaces, 2(5), 2010, 1536-1542.

[8] X. Zhang , W.Shi ,J. Zhu, D.J. Kharistal , W.Zhao , High-Power and High-Energy-Density Flexible Pseudocapacitor Electrodes Made from Porous CuO Nanobelts and Single-Walled Carbon Nanotubes, ACS Nano.,5(3), 2011,2013–2019.

[9] A.P. Jia , S.Y. Jiang , J.Q.Lu , M.F. Luo ,Study of Catalytic Activity at the CuO-CeO2 Interface for CO Oxidation, J. Phys. Chem. C.,114, 2010,21605–21610.
[10] T. Li, X.P. Ai , H.X. Yang , Reversible Electrochemical Conversion Reaction of Li2O/CuO Nanocomposites and Their Application as High-Capacity Cathode Materials for Li-Ion Batterie , J. Phys. Chem. C. , 115,2011,6167–6174.

Abstract: In fact, the vertical position of Michelson-Morley experiment is not the only possible explanation for the new phenomenon of the vertical Aether flow into any mass or any fundamental building block. This paper shows, for the first time, that the cosmic blue shift due to a gravitational field is a direct consequence of the vertical Aether flow into any mass. The vertical Aether speeds of different stellar objects have been given, which suggest reclassifying the categories of black holes. To confirm the theory presented, new formulas for Doppler Effect in a gravitational field and its correlation with the time dilation, as derived from the General Relativity, has also been derived. The theoretical expressions corresponding to the two experimental results have been given. Also, a new prediction has been proposed, for the first time, to confirm the theories presented in this paper.

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Abstract: CdO-Mn3O4 nanocomposite has been prepared by a simple solvothermal method using a domestic microwave oven. Cadmium acetate, manganese acetate and urea were used as the precursors and ethylene glycol as the solvent. The as-prepared sample was annealed for 1 hour in each case at different temperatures, viz. 100, 200 and 300°C. The as-prepared and annealed samples were characterized by X-ray diffraction and scanning electron microscopic analyses. Results indicate that annealing at 300°C is required to get the sample with high phase purity and homogeneity. The present study indicates that the method adopted can be considered as an economical and scalable one to prepare the proposed nanocomposite with reduced size, phase purity and homogeneity.

Keywords: Nanoparticles, Nanocomposites, Solvothermal method, X-ray diffraction, SEM analysis.

[1] Jinghong Li and Jin Z. Zhang, Optical properties and applications of hybrid semiconductor nanomaterials, Coord Chem Rev, 253(23-24), 2009, 3015-3041.
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[7] Weixin Zhang, Zeheng Yang, Yi Liu, Shupei Tang and Xiaozhao Han Min Chen, Controlled synthesis of Mn3O4 nanocrystallites and MnOOH nanorods by a solvothermal method, J Cryst Growth, 263(1-4), 2003, 394-399.
[8] Maryam Lashanizadegan and Hoda Mirzazadeh, Synthesis of (CdOH)2 and CdO nanoparticles via a PEG assisted route, J Ceram Process Res, 13(4), 2012, 389-391.
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Abstract: CoxZn1-xS (x=0-0.1) polycrystalline semiconductor compounds were synthesised by co-precipitation method and were characterised by X-ray diffraction (XRD), UV-absorption, EDAX, SEM and Fourier Transform Infrared (FTIR) studies. XRD studies have shown that these powders have polycrystalline nature with a gradual variation from hexagonal to cubic structure while x changing from 0 to 0.1. UV-abosrption studies revealed that the band gap of CoxZn1-xS (x=0-0.1) samples decreased with increase in cobalt concentration, owing to the enhancement of sp-d exchange interactions and typical d-d transitions. Chemical homogeneity and surface morphology studies were carried out by using EDAX and SEM. Fourier Transform Infrared (FTIR) spectroscopy also revealed that cobalt is induced into the lattice replacing Zinc.

Keywords: Polycrystalline Semiconductor CoxZn1-xS, X-ray Diffraction, EDAX, SEM, Optical Properties.

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[7] K. Siva Kumar, A. Divya and P. Sreedhara Reddy, Synthesis and characterization of Cr doped CdS nanoparticles stabilized with polyvinylpyrrolidone, Applied Surface Science, 257(22), 2011, 9515-9518.
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Abstract: In recent years there has been an increasing interest in the use of natural substances, and some questions concerning the safety of synthetic compounds have encouraged more detailed studies of plant resources. Essential oils, odorous and volatile products of plant secondary metabolism, have a wide application in folk medicine, food flavoring and preservation as well as in fragrance industries. In our present work with the vibrational spectroscopy of quantum chemical calculations of Eugenol,Geronial have been carried out. The compounds are responsible for most of the characteristic aroma .DFT analysis is performed before and after application of clove oil on Asbergillus fungi..Vibrational analysis on Eugenol( 4-allyl-2-methoxyphenol is also carried out.The fluorescent property of the material was also discussed.

Key words: Essential oils, Antibacterial activity, Antifungal activity ,Eugenol (4-allyl-2-methoxyphenol)

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[3] X. Tai, X. Yin, Q. Chen, and M. Tan, "Synthesis of some transition metal complexes of a novel Schiff base ligand derived from 2,2_-bis(p-methoxyphenylamine) and salicylicaldehyde," Molecules, vol. 8, no. 5, pp. 439–443, 2003.

[4] A. A. H. Kadhum, A. B. Mohamad, A. A. Al-Amiery, and M.S. Takriff, "Antimicrobial and antioxidant activities of new metal complexes derived from 3-aminocoumarin," Molecules, vol. 16, no. 8, pp. 6969–6984, 2011.

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Abstract: This paper is an extended review paper about the use of a new intensity formula in optical emission spectroscopy, atmospheric physics and astronomy. The laboratory data of atomic- and ionic spectra from different light sources do support the new formula. In the atmospheric field dominant light mechanisms in aurora have been revealed, which follow the new formula. The inverse of this formula can also be used to show the photoelectric effect for many elements. In astronomy new methods have been developed of determining electron- and effective temperature, density and mass of stars with the new formula as a basis, which are in accordance with literature values. An investigation of the Balmer lines in the sun shows that they do follow the new formula. Therefore the new formula is important in the sun and the stars.

Keywords: Optical emission spectroscopy, Analytical Chemistry, Light sources, Spectral tables UV-IR, Atmospheric emissions, Auroral spectroscopy, Astrophysics, Linear relationships, Photoelectric effect, Star temperature determinations, Star density determinations and Star mass determinations.

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Abstract: The activity concentrations of naturally occurring radionuclides (40 K, 226 Ra 232 Th) in nine organic fertilizers were measured using NaI (Tl) gamma ray spectrometry. The results show that 40K mean activity concentration was 305.33±0.196Bqkg-1 ranging from 120Bq/kg to 907 Bqkg-1, 232Th mean concentration was 45.04Bqkg-1 ranging from 14.66 Bq/kg to 60.20Bqkg-1. While 226Ra mean concentration was 24.87±0.02Bqkg-1 with a range of 12.83 to 65.69Bqkg-1. Radiological hazard indices were calculated and the mean air absorbed dose rate was 51.59nGyh-1 it ranged from 30.33 to 101.23nGyh-1. The annual effective dose rate averaged 61.33μSvy-1(0.061) which is lower than the world average (0.07μSvy-1) it ranged from 33.39 to 124.51μSvy-1. The Raeq was 112.90Bqkg-1 which is far below the 370Bqkg-1maximum.The Hex and Hin averaged 0.31 and 0.37respectively. From Radiological point, organic fertilizers do not impart significant radiological risk, because the radiological hazard indices are lower than Bench marks. Key words: Activity concentrations, Radionuclides, Health implications, Gamma ray, organic fertilizers

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Abstract: Nanocrystalline multiphase CaCu3Ti4O12 (CCTO) was prepared using Ca(NO3)2.4H2O, Cu(NO3)2.3H2O, TiO2 and C2H2O4.2H2O. The X-Ray differection and SEM analysed of the prepared CCTO powder sintered at 900oC and 950oC. A homogeneous ceramics-polymer nanocomposites consisting of CCTO particles as fillers and epoxy polymer as matrix have been prepared using a casting process. The nanocomposites exhibit enhanced dielectric constant and dielectric loss. Dielectric properties of CCTO ceramics were characterized in a broad frequency range (100 Hz-1 MHz) and at a temperature ranged from 25 oC to 150 oC. As a result of increasing the content of CCTO, the dielectric constant and dielectric loss of composites are increased. The increase of dielectric loss at high frequencies is due to the relaxation process in the polymer matrix.

Keywords: Dielectric Constant , CCTO, Nanopartical.

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Abstract: Dirac-Maxwell's equations, retained for magnetic monopoles, are generalized by introducing magnetic scale field. It allows the magnetic monopoles to be time-dependent and the potentials to be Lorentz gauge free. The non-conserved part or the time-dependent part of the magnetic charge density is responsible to produce the magnetic scalar field which further contributes to the magnetic and electric vector fields. This contribution makes possible to create an ideal square wave magnetic field from an exponentially rising and decaying magnetic charge.

Keywords: Dirac-Maxwell's equations, Lorentz Gauge, Magnetic scalar field

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Abstract: This study aimed at designing an improved hybrid algorithm by explicitly solving the linearized Boltzmann transport equation (LBTE) which is the governing equation that describes the macroscopic behaviour of radiation particles (neutrons, photons, electrons, etc). The algorithm accuracy will be evaluated using a newly designed in-house verification phantom and its results will be compared to those of the other XiO photon algorithms. The LBTE was solved numerically to compute photon transport in a medium. A programming code (algorithm) for the LBTE solution was developed and applied in the treatment planning system (TPS). The accuracy of the algorithm was evaluated by creating several plans for both the designed phantom and solid water phantom using the designed algorithm and other Xio photon algorithms. The plans were sent to a pre-calibrated Eleckta linear accelerator for measurement of absorbed dose.The results for all treatment plans using the hybrid algorithm compared to the 3 Xio photon algorithms were within 4 % limit. Calculation time for the hybrid algorithm was less in plans with larger number of beams compared to the other algorithms; however, it is higher for single beam plans. The hybrid algorithm provides comparable accuracy in treatment planning conditions to the other algorithms. This algorithm can therefore be employed in the calculation of dose in advance techniques such as IMRT and Rapid Arc by a radiotherapy centres with cmsxio treatment planning system as it is easy to implement.

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Abstract: The discovery of GMR opened new windows in the field of nano-materials, and nowadays research in these materials has become fashionable due to its tremendous technological potential and the deep fundamental physics involved in it. The discovery of giant magneto-resistance (GMR) has been a huge impact on our life, especially for mass data storage devices. Initial experiments conducted by Grunberg and Fert are explained. Basic physics of the GMR effect can be explained by the two-current model, which the conduction of a current is, consist of two different spin electrons. Details of GMR applications, such as hard-disk read-heads, sensors and magnetic memory chips are presented. One of the important aspects of GMR discovery was that it was immediately turned into commercially available products (the first GMR Hard disk head was introduced by IBM in 1997) with a giant market share. The highest storage capacity in the modern computers is attributed to the discovery of GMR. The story of GMR effect tells us how an unexpected scientific discovery could give rise to completely new technologies, new science and new commercial products, that means the new technology promises smaller and faster tools.

Keywords: GMR; Spin Dependent Tunneling (SDT); Hard disk drive; Sensors; Spin-Valve

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