IOSR-JAP   Volume-13 ~ Issue-6 ~ Nov. – Dec. 2021

ABSTRACT: This article derives a simple linear model for semiconductor bandgap variation with temperature. The model is based on the theorem of equipartition of energy for the electrons and holes at thermal equilibrium which gives the average kinetic energy of an electron or hole to be 3/2(kT). The calculated bandgaps at temperatures of 100K to 600K of Silicon matches with the observed experimental values to within ±1%. The model is applicable to bandgaps of all covalently bonded semiconductors at high temperatures and is possibly valid for the electron work functions of metals and the oxide/semiconductor band offsets as well..

Keywords: Bandgap, Semiconductors, Silicon, Silicon Carbide, Temperature

[1]. G.L. Pearson, J. Bardeen, "Electrical properties of pure silicon and silicon alloys containing Boron and Phosphorus", Physical Review, 1949;75(5):85-883.
[2]. H.Y. Fan, "Temperature dependence of the energy gap in semiconductors", Physical Review, 1951;82(6):900-905.
[3]. Y.P. Varshni, "Temperature dependence of the energy gap in semiconductors", Physica, 1967;34:149-154.
[4]. C.D. Thurmond, "The standard thermodynamic functions for the formation of electrons and holes in Ge, Si, GaAs, and GaP", J. Electrochemical Soc., Solid-State Science and Technology, 1975;122(8):1133-1141.
[5]. G.G. Macfarlane, T.P. McLean, J.E. Quarrington, V. Roberts, "Fine structure in the absorption-edge spectrum of Si", Physical Review, 1958;111(5):1245-1254..

ABSTRACT: The concentrations of the naturally occurring radionuclides in rock fragments from two quarry sites in Akamkpa, Cross Rivers State, South-south Nigeria have been measured, using gamma ray spectrometry (NaI (TI) detector). The photo peaks observed with reliable regularity in all the samples analysed belonged to the naturally occurring radionuclides......

Keywords: Gamma radiation, natural radionuclide, Gamma spectroscopy, radioactivity, quarry sites

[1]. Avwiri, G.O. (2011). Radiation–The Good, the Bad and the Ugly in our Environment. AnInaugural Lecture 79th Series University of Port Harcourt Press
[2]. Shittu H. O., Olarinoye I.O., Baba-Kutigi A.N., Olukotun S.F., Ojo E.O., & Egga A. (2015). Determination of the Radiological Risk Associated with Naturally Occurring Radioactive Materials (NORM) at Selected Quarry Sites in Abuja FCT, Nigeria: Using Gamma-Ray Spectroscopy. American Institute of Science.PhysicsJournalVol. 1, No. 2, 2015, pp. 71-78.
[3]. United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR, 2000). Sources and effects of ionizing radiation. Report to General Assembly, with Scientific Annexes, United Nations, New York, USA. [4]. Faanu A, Kpeglo DO, Sackey M, Darko EO, Emi-Reynolds G, Lawluvi H, Awudu R, Adukpo OK, Kansaana C, Ali ID, Agyeman B, Agyeman L, Kpodzro R. Natural and artificial radioactivity distribution in soil, rock and water of the Central Ashanti Gold Mine. Ghana: Environ Earth Sci; 2013.
[5]. Ekwueme B, Nyong N, Petters SW (1995). Geological and excursion map of Cross River State Geological guide of Cross River State 1: 9.

ABSTRACT: In this study, we present the results obtained in our investigation of the heat dissipation efficiency of the U-shaped liquid-cooled configuration for LED bulbs. Measurement results showed that the U-shaped liquid-cooled configuration did improve heat dissipation efficiency by reducing the temperature of LED chips from 9°C to 12°C compared to conventional heat dissipation without using liquid. In addition to that, our estimated calculation also showed that the U-shaped liquid-cooled configuration helped to increase the chip's lifetime by about 248%, compared to the conventional cooling method without using liquid. At the same time, because of its high transparency, the liquid does not affect the brightness of the bulb at all. Finally, the use of a U-shaped configuration saves liquids and increases the contacted surface areas with the environment, thus greatly improving the heat dissipation efficiency of LED bulbs even more [1].

Keywords: Heat dissipation, U-shaped liquid-cooled configuration, LED bulbs, durability, lifetime.

[1]. Patent application "U-shaped liquid-cooled configuration for LED bulbs", No. 9553w/QD-SHTT dated 11/06/2021.
[2]. Feng S, Liu Z, Cheng B, Sun S, Lu T.J, Xu F, Design of a novel LED bulb with entire surface thermally activated for passive cooling. Applied Thermal Engineering, 2021, 198, 117466.
[3]. Pan M, Chen Z, Li C, Experiment and simulation analysis of oriented cut copper fiber heat sink for LED water cooling. Case Studies in Thermal Engineering, 2021, 24, 100878.
[4]. Liu W, Liu Y.F, Wang L, Malcolm D, "A 3D stacked step-down integrated power module", 2017 IEEE Applied Power Electronics Conference and Exposition (APEC).
[5]. Guorong S, Chen J, Ni H, Ma Y, Gao Z, Wang N, Improvement of LED Performance with an Integrated Thermoelectric Cooling Package. IEEE Access, 2020, PP. 1-1..

ABSTRACT: In this work, The (BaxFe1-xTiO4) (x=1, 0.1, 0.2, 0.3, 0.5, 0.6, 0.7,08, 0.9 and 0) were prepared by the sol- gel. The effect of Fe concentration on the Nano structure and optical properties of the samples were studied by using x-ray diffraction (XRD), and UV-VIS spectroscopy. The X-ray diffraction (XRD) analyses show that for all samples the average Nano size decreases upon decreasing iron concentration. UV-visible absorption spectra shows that decreasing iron concentration increases absorption coefficient. Moreover decreasing Nano size, increases absorption coefficient.

Keywords: Nano size, dielectric, absorption coefficient, crystal size, x-ray diffraction, Ultra violet

[1]. Chen, K., Chen, X., Xue, D., Hydrothermal route to crystallization of FeOOH nanorods via FeCl36H2O: effect of Fe3+ concentration on pseudocapacitance of ironbased materials, 2015.
[2]. Arico AS, Bruce P, Scrosati B, Tarascon J-M, Schalkwijk WV Nanostructured materials for advanced energy conversion and storage devices. (2005) Nat Mater 4:366–377
[3]. Claassen, J.O., Sandenbergh, R.F. Influence of mixing on the quality of iron precipitates in zinc-rich solutions. Hydrometallurgy. 2007
[4]. Clogston, J., Patri, A.,. Characterization of nanoparticles delivery intended for drug delivery. In: McNeil, S.E. (Ed.), Methods in Molecular Biology. Springer, New York, pp. 63–70, 2011
[5]. Jeevanandam, J., Barhoum, A., Chan, Y.S. et al. Review on nanoparticles and nanostructured materials: history, sources, toxicity and regulations (2018)..

ABSTRACT: The goal of this work is to investigate the total cross section of electrons, atoms, and molecules in iron oxides. On the basis of this total cross section, one can choose the best radiation shielding material of iron oxides in a radiation field ranging from 0MeV to 10MeV. At low energy, the total cross section of electrons, atoms, and molecules is large, indicating that scattering is significant. High scattering indicates photon divergence and material protection behind the target, implying radiation shielding. As a result, the best radiation shielding material is iron rich oxides with a high FW of iron. Electrons have a smaller total cross section than atoms and molecules. The total cross section of electrons, atoms, and molecules is the same as that of a high energy photon

Keywords: Total cross section, Photon, Radiation shielding material, Iron Oxides.

[1]. Limkitjaroenporn P, Kaewkhao J, Chewpraditkul W, Limsuwan P. Mass Attenuation Coefficient and Effective Atomic Number of Ag/Cu/Zn Alloy at Different Photon Energy by Compton Scattering Technique. Procedia Engineering. 2012;32:847 – 854.
[2]. Turgut U, Ims OS¸ Ukkasap EB. Measurement of mass attenuation coefficients in some Cr, Co and Fe compounds around the absorption edge and the validity of the mixture rule. Pramana: Journal of Physics. 2017;69(2):99-200.
[3]. Yilmaz D, Ahin YS, Demir L. Studies on mass attenuation coefficient, mass energy absorption coefficient, and kerma for Fe alloys at photon energies of 17.44 to 51.70 keV, Turkish Journal of Physics. 2015;339:81-90.
[4]. Junior TAA, Nogueira MS, Vivolo V, Potiens MPA, Campos LL. Mass attenuation coefficients of X-rays in different barite concrete used in radiation protection as shielding against ionizing radiation. Radiation Physics and Chemistry. 2017;140:349–354.
[5]. Akça B, ErzeneoLlu SZ. The Mass Attenuation Coefficients, Electronic, Atomic, and Molecular Cross Sections, Effective Atomic Numbers, and Electron Densities for Compounds of Some Biomedically Important Elements at 59.5 keV. Science and Technology of Nuclear Installations. 2014;2014:1-8..

ABSTRACT: God's Particles by definition are the building blocks of the universe. Logically God's Particles should obey Five Principles of The Universe. Also, they should be able to build all matters in the universe especially those subatomic particles with Four Basic Forces. Based on the Five Principles of The Universe, a pair of super fine anti-particles (Yangton and Yington) with an inter-attractive force (Force of Creation) can be created temperately from vacuum space. Consequently, in compliance with Big Bang Theory, a permanent circulating particle pair (Wu's Pair) composed of Yangton and Yington particles can be generated as the building blocks (God's Particles) of the universe. In this review paper, subatomic particle structures and Four Basic Forces based on Wu's Pairs and Yangton and Yington Theory are studied. Also, Standard Model and Quantum Field Theory are compared with.....

Keywords: God's Particles, Wu's Particles, Yangton and Yington Theory, Force of Creation, String Theory, String Force, Four Basic Forces, Gravitational Force, Electromagnetic Force, Weak Force, Strong Force, Magnetic Force, Proton, Neutron, Unified Field Theory, Subatomic Particles, Standard Model, Quark, Electron, Positron, Neutrino, Gluon, Photon, Graviton, Higgs Boson, Wave Particle Duality, Quantum Field Theory, Quantum Gravity Theory..

[1]. Edward T. H. Wu" Five Principles of The Universe and the Correlations of Wu's Pairs and Force of Creation to String Theory and Unified Field Theory." IOSR Journal of Applied Physics (IOSR-JAP), vol. 10, no. 4, 2018, pp. 17-21.
[2]. Edward T. H. Wu, "Yangton and Yington–A Hypothetical Theory of Everything", Science Journal of Physics, Volume 2015, Article ID sjp-242, 6 Pages, 2015, doi: 10.7237/sjp/242.
[3]. "Big-bang model". Encyclopedia Britannica. Retrieved 11February 2015.
[4]. Edward T. H. Wu. "Subatomic Particle Structures and Unified Field Theory Based on Yangton and Yington Hypothetical Theory". American Journal of Modern Physics. Vol. 4, No. 4, 2015, pp. 165-171. doi: 10.11648/j.ajmp. 20150404.13.
[5]. "Subatomic Particle" Encyclopedia Britannica. Retrieved 2008-06-29.

ABSTRACT: A body is said to be in equilibrium[1] if it is at rest or moving with uniform velocity. In other words if the linear and angular acceleration of a body are zero, the body is said to be in Equilibrium. or we can say that when two or more forces act on a body such that their resultant or combining effect on the body is zero and the body retains its state of rest or of uniform motion then the body is said to be in equilibrium. Introduction A spring is regarded [1]as weightless, as always obeying Hooke's law and as having zero cross-sectional area so that it always lies along a straight line. Our reason for using such an abstraction instead of a real spring is that we believe it reproduces the main phenomena of oscillatory motion involving a spring while reducing considerably the mathematical complexity. Then the connection between force and motion is given by........

[1]. Applying general equilibrium Shoven, John B and Whalley, John, 1992, Cam- bridge university press
[2]. Informational equilibrium Riley, John G 1979, JSTOR
[3]. A classificatory note on the determinateness of equilibrium Kaldor, Nicholas, 1934, JSTOR
[4]. Foreword: Law as equilibrium Eskridge Jr, William N and Frickey, Philip P, 1994, HeinOnline
[5]. Equilibrium unemployment theory Pissarides, Christopher A, 2000, MIT press
[6]. Institutional equilibrium and equilibrium institutions Shepsle, Kenneth A, Polit- ical science: The science of politics, 51, 1986

ABSTRACT: This paper presents the design and development of a high-performance computer cluster that can perform parallel computational task in batch mode. In order to benchmark the performance of the developed system, we have studied two cases related to the intense computational task. Firstly, we performed a simulation using Gaussian09 package with time dependent density functional theory at B3LYP/6-31G level to find out the UV-vis Spectrum of L-Tyrosine by increasing the number of compute nodes. The absorption spectra were also compared with the experimentally obtained results from the UV-vis spectrometer. Secondly, we dealt with a three-body problem by solving the Sitnikov equation of motion.

Keywords: High Performance Computing, Computer Cluster, Parallel Computing, Gaussian09 Simulation. UV-VIS Spectroscopy, L-Tyrosine, Sitnikov solution..

[1]. Eijkhout, V., Chow, E., & Geijn, R. v. (2011). Introduction to High Performance Scientific Computing (1st Edition ed.). Texas: The Saylor Foundation.
[2]. Becker, D. J., Sterling, T., Savarese, D., Dorband, J. E., Ranawak, U. A., & Parker, C. V. (1995). Beowulf: A Parallel Workstation for Scientific Computation. International Conference on Parallel Processing.Stavrakas, I. K. (2005). Beowulf Clusters for Parallel Programming Courses. The International Conference on Computer as a Tool. 1, pp. 791-794. IEEE.
[3]. Ayanda, D. &. Adejumo (2011). A Prototype Model of High Performance Computing Using Beowulf Cluster. International Journal of Emerging Sciences, 1 (4), 696-705.
[4]. Gaussian 09, Revision A.02, M. J. Frisch et al, Gaussian Inc.,Wallingford, CT 200, 2009, 28.
[5]. T. H. Dunning, Gaussian basis sets for use in correlated molecular calculations. I. The atoms boron through neon and hydrogen. J. Chem. Phys. 90, 1989, 1007..

ABSTRACT: The zinc oxide thin film have been synthesized and studied as the sensing element for the detection of H2S gas. The zinc oxide thin films were synthesized by dip-coating method. Gas sensing properties of zinc oxide thin films were studied for H2S, LPG and NH3 gases by changing the concentration of test gases. The prepared zinc oxide thin films can be used as promising material for semiconductor gas sensor for poisonous gases like H2S with high sensitivity. We report the conducting and transparent ZnO thin films fabricated by sol-gel dip -coating method. XRD, UV-VIS, SEM and PL are used to characterize these films. X- ray diffraction studies show that films are polycrystalline in nature and have hexagonal wurtzite structure. These films are found to show (002) preferential growth

Keywords: Zinc oxide; Thin film; Gas sensors; Dip coating; XRD; SEM.

[1]. R. Ionescu, A. Hoel, C.G. Granqvist, E. Llobet, P. Heszler, Low-level detection of ethanol and H2S with temperature-modulated WO3 nanoparticle gas sensors, Sens. Actuators B 104 (2005) 132–139.
[2]. M. Kaur, S. Bhattacharya, M. Roy, S.K. Deshpande, P. Sharma, S.K. Gupta, J.V. Yakhmi, Growth of nanostructures of Zn/ZnO by thermal evaporation and their application for room temperature sensing of H2S gas, Appl. Phys. A 87 (2007) 91–96.
[3]. Abideen, Z., Kim, J.-H., Mirzaei, A., Kim, W. H., and Kim, S. S. (2018). Sensing behavior to ppm-level gases and synergistic sensing mechanism in metal-functionalized rGO-loaded ZnO nanofibers.Sens. Actuat. B Chem. 255, 1884–1896.
[4]. Yue, Y., and Yu, H. (2019). Study on gas sensitivity of new SnO2 nanosheets. Enterprise Sci. Technol. Dev. 6, 90–91.
[5]. M. Kaur, S. Bhattacharya, M. Roy, S.K. Deshpande, P. Sharma, S.K. Gupta and J.V. Yakhmi, Growth of nanostructures of Zn/ZnO by thermal evaporation and their application for room temperature sensing of H2S gas, Appl. Phys. A 87 (2007) 91–96

ABSTRACT: The Big Bang gives the universe the force to continue to expand, but it would stand to reason that gravity would eventually slow this force down. When gravity begins to overpower this force the universe would begin to contract. Several cosmological observations demonstrated that the universe is expanding. By studying supernovae type Ia (SNe Ia), it was found that the universe's expansion is speeding up rather than slowing down, as was expected if only matter and radiation were present. This unknown 'anti-gravity' force at work is termed 'dark energy'. Dark energy or cosmological constant or quintessence is an unknown form of energy. This is the dominant component.......

Keywords: Dark energy, Dark matter, ΛCDM universe, Cosmological constant, Supernovae Ia etc.

[1]. Robert P. Kirshne Hubble's diagram and cosmic expansion vol. 101 no. 1 Proceedings of National Academy of Sciences of United States of America
[2]. "Type Ia Supernova". Weekly Topic. Caglow. Retrieved 30 January 2012.
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[4]. HUBBLE Riess, A.; et al. (September 1998). "Observational Evidence from Supernovae for an Accelerating Universe and a Cosmological Constant". The Astronomical Journal 116 (3): 1009–1038. arXiv:astro-ph/9805201.Bibcode:1998AJ.116.1009R.
[5]. Perlmutter, S.; et al. (June 1999). "Measurements of Omega and Lambda from 42 High-Redshift Supernovae".The Astrophysical Journal 517 (2): 565–586. arXiv:astro-ph/9812133. Bibcode:1999ApJ...517..565P.doi:10.1086/307221