IOSR-JAP   Volume-12 ~ Issue-3 ~ May – Jun. 2020

ABSTRACT:The study was carried out on a series of 360 samples of Scots pine wood (Pinus sylvestris). A part of them were in their natural state, but the majority of them were superficially polymerized with poly(methyl acrylate). The test specimen comprised natural and modified wood with varying poly(methyl acrylate) (PMM) contents. The samples were tested for tensile strength on a universal testing machine. The purpose of the experiment was to examine the ways, in which polymerization improves on the strength properties and how the properties of materials change if the angle α between the load direction and the fiber orientation changes. An additional purpose of the study was to select an adequate strength criterion to describe the tested composite materials. Samples made of modified wood were uniaxially stretched at an angle of α = 0, 15, 30, 45, 60 and 90⁰, measured between the direction of the load and the longitudinal direction of the fibers......

Key Word: natural wood, modified wood, static tensile test, strength criteria.

[1]. Kowalski S.J., Kyzioł L., Rybicki A., Composite of wood and polymerized methacrylate, Composites: Part B Vol. 33, 2002, pp. 77-
86.
[2]. Kyzioł L. Wood modified for marine structures. Gdynia: Publisher Naval Academy in Gdynia; 2010.
[3]. Y. Li, Wood-Polymer Composites, Intech (2011).
[4]. Kyzioł L., Reinforcing wood by surface modification, Composite Structures 158, (2016), pp. 64–71, http://dx.doi.org/10.1016/j.compstruct.2016.06.055.
[5]. Kyzioł L., Szwabowicz M., Toughness of Scots pine – polymethyl methacrylate composite, Polymer Composites, Vol. 40, Issue 2, 2019, pp. 811-822, DOI: 10.1002/pc.24740).

ABSTRACT:Ni0.7-xZn0.3CaxFe2O4nanoparticles with different Ca concentration were synthesized by chemical co-precipitation technique at different annealing temperatures. The influence of Ca content on the electrical conduction was investigated as a function of frequency and temperature. The ac conductivity, σac, was found to be increases with both temperature and frequency, confirmed semiconductor behavior for all samples. The addition of Ca2+ decrease σacup to certain Ca content. The calculated values of activation energies mainly increase with Zn2+ content and sintering temperature. The dependence of σac on frequency is governed by the relation σac = Aωs. The calculated values of s recorded decreasing with increasing temperature for all studied samples. In the low temperature range......

Keywords- Conduction mechanisms, Nanocomposites, Dielectric, coprecipitation

[1]. H. Shokrollahi, K. Janghorban, J. Magn. Magn. Mater. 308, 238 (2007)
[2]. H. Shokrollahi, K. Janghorban, Iran. J. Sci. Technol. Trans. B: Eng. 30, 413 (2006)
[3]. J. Azadmanjiri, H.K. Salehani, M.R. Barati, F. Farazan,Mater. Lett. 61, 84 (2007)
[4]. Z. Yue, L. Li, J. Zhou, H. Zhang, Z. Gui, Mater. Sci. Eng. B 64, 68 (1999)
[5]. U.N. Trivedi, K.H. Jani, K.B. Modi, H.H. Joshi, Mater.Sci. Lett. 19, 1271 (2000)

ABSTRACT: Semi-classical transport thermoelectric properties of γ-CuI are investigated using density functional theory (DFT) calculation containing Boltzmann transport equations. The Tran–Blaha modified Becke–Johnson potential (Tb-mBJ) approximation is used as the exchange correlation potential. Thermoelectric properties such as, Seebeck co-efficient, electrical conductivity, thermal conductivity, power factor, figure of merit, thermoelectric voltage and thermoelectric conversion efficiency are discussed with constant relaxation time as a function of chemical potential. This is because the chemical potential is directly related with the carrier concentration and temperature. These parameters are strongly dependent on the doping level and temperature. The maximum range of.......

Keywords: Copper Iodide; Density functional theory; thermoelectric properties; chemical potential

[1]. C. Yang, D. Souchay, M. Kneiß, M. Bogner, H.M. Wei, M. Lorenz, O. Oeckler, G. Benstetter, Y.Q. Fu, M. Grundmann, Transparent flexible thermoelectric material based on non-toxic earth-abundant p-type copper iodide thin film, Nature Communications 8 (2017) 16076.
[2]. R. Venkatasubramanian, E. Siivola, T. Colpitts, B. O'Quinn, Thin-film thermoelectric devices with high room-temperature figures of merit, Nature 413 (2001) 597.
[3]. T.C. Harman, P.J. Taylor, M.P. Walsh, B.E. LaForge, Quantum Dot Superlattice Thermoelectric Materials and Devices, Science 297(5590) (2002) 2229-2232.
[4]. Y. Gelbstein, Phase morphology effects on the thermoelectric properties of Pb0.25Sn0.25Ge0.5Te, Acta Materialia 61(5) (2013) 1499-1507.
[5]. K. Kirievsky, M. Shlimovich, D. Fuks, Y. Gelbstein, An ab initio study of the thermoelectric enhancement potential in nano-grained TiNiSn, Physical Chemistry Chemical Physics 16(37) (2014) 20023-20029.

ABSTRACT:Résumé : Les besoins en énergies au monde se sont accrus avec la croissance de la population mondiale. Et cela depuis la révolution industrielle du 18ème siècle, et avec comme conséquence l'augmentation de l'effet de
serre. Pour ralentir tant soit peu les changements climatiques d'origine anthropique, les spécialistes du Groupe International d'Experts sur le Climat (GIEC en sigle) ont alors depuis plus d'une décennie recommandé
l'exploitation des énergies renouvelables. Au Sud-Kivu, aux sites où il y a des thermes, on peut consommer propre en produisant et exploitant de l'électricité géothermique. La population de Kankule et environs, à
Katana au Sud-Kivu, peut alors bénéficier de cette manne qui s'élèverait à de Mégawatts de puissance électrique produite. Ceci en vue de réduire la déforestation et ses conséquences sur le climat.......

[1]. Adelin Mulenda, 2013, Modélisation du transfert des températures sol-air-eau thermale de Kankule dans Katana au Sud-Kivu, Mémoire de D.E.A présenté à l'Université Pédagogique Nationale de Kinshasa (UPN /Kin), Faculté des Sciences, Département de Physique.
[2]. Albert KABASELE YENGA-YENGA, 2019, Modélisation du Fleuve Congo Et Marées Océaniques de Muanda Par Climatologie Spatiale, Géosciences et Innovations Spatiales, Kinshasa.
[3]. Albert KABASELE YENGA-YENGA, 2009, Modélisation Saisonnière Limnimétrie. Atmosphère et Imagerie satellitaire LANDSAT / SRTM dans le Bas Fleuve RD Congo, Thèse de Doctorat présentée à l'Université Pédagogique
[4]. Albert KABASELE YENGA-YENGA et alii, 2017, Utilisation de Station Virtuelle LANSAT en Orbite Héliosynchrone dans l'Amélioration et la Validation des Anomalies Climatiques in Situ sur la ville Province de Kinshasa, Géosciences et Innovations Spatiales, Kinshasa.
[5]. BagalwaMasimango Jean-Jacques et alii, 2016, Caractérisation physico-chimique des espèces végétales indicatrices des eaux thermales de Katana, Sud-Kivu, République Démocratique du Congo, Afrique Science 11(5) (2015) 406-421 406 ISSN 1813-548X.

ABSTRACT: This paper provides the reason for existence of magnetic field. Oersted Law states a relation between magnetic field and electric current. From the same law, a relation is derived between magnetic flux, electric flux and velocity. it has been established that the magnetic flux opposes the resultant vector of electric flux and velocity. The vector analysis demonstrates the reason for magnetic field being circular around conductor. This analysis proves magnetic field is not a fundamental field. The direction of electric field around charged particles is found to be opposite to what conventionally accepted. This analysis also provides clue to universal consciousness and wisdom..

Keywords: Magnetic field, fundamental field.

.......

ABSTRACT:It is shown that in semiconductors with two types of charge carriers, in the presence of a temperature gradient, taking hydrodynamic motions into account leads to the excitation of growing waves. The frequency
and increment of this wave are determined. Expressions are found for the external electric and magnetic fields upon excitation of growing waves. It has been proven that growth occurs in samples with a certain size. It was
found that the speed of the rising waves is the same in all directions of the coordinate axes and is proportional to the speed of thermomagnetic waves. The concentration ratio of electrons and holes is found upon the
appearance of growing waves..

Keywords: semiconductor, electric field, magnetic field, electrons, holes, frequency

[1]. E R Hasanov, R K Qasimova, A Z Panahov, A I Demirel, Ultrahigh Frequency Generation in Ga-As- type , Studies Theor Phys, 3(8), (2009), 293-298.
[2]. E.R. Hasanov, Rasoul Nezhad Hosseyn, A.Z. Panahov and Ali Ihsan Demirel, Instability in Semiconductors with Deep Traps in the Presence of Strong ( H  C)   , Advanced Studies in Theoretical Physics, 5(1), (2011), 25-30.
[3]. A.I. Demirel, A.Z. Panahov, E.R.Hasanov. Radiations of electron –type conductivity environments in electric and magnetic field,
Advanced Studies in Theoretical Physics, (22), (2013), 1077-1086.
[4]. F.F.Aliev, E.R.Hasanov. Nonlinear Oscillations of the charge the Curriers Concentration and Electric Field in Semiconductors with Deep Traps, IOSR Journal of Applied Physics, Volume 10, Issue 1 Ver. II (Jan.-Feb. 2018), p. (36-42)
[5]. E.R.Hasanov, R.A.Hasanova. External and Internal Instability in the Medium Having Electron Typ Conductivity, IOSR Journal of Applied Physics, Volume 10, Issue 3 Ver. II (May-June. 2018), p. 18-26

ABSTRACT:In a paper published in Physics Essays the author had derived the London equations from some basic
assumptions. We had found there that there is a curvature of spacetime and a localized surface tension. We
continue explaining the free energy expansion in Ginzburg Landau theory and find the rest of the hidden
variables,

[1]. About a possible derivation of the London equations, SpirosKoutandos, Physics essays,vol 33, no2 ,2020
[2]. Introduction to superconductivity, Michael Tinkham, Dover editions

ABSTRACT:Noise generated in public places has become a matter of public concern to the Government, traders, merchants and other close residents. Exposure to excessive noise has the ability to cause both physiological and psychological effects in humans. In this research systematic noise evaluation survey was conducted at different strategic locations within Kara market Sokoto, Sokoto state Nigeria. A cumulative noise level of 90.55 dBA was obtained at the grains market; while the wood market showed cumulative noise level of 78.15dBA.The iron work market, onion market and Motor Park showed cumulative noise levels of 72.42dBA, 62.52dBA and 80.88dBA respectively. Minimum and maximum noise levelswere compared with the WHO noise standards. Findings of the research indicated that the use of grinding engines, wood cutting machines and public address systems generated most of the noise

[1]. FEPA. 1991 Guidelines and standards for environmental pollution control in Nigeria. Federal Ministry of Environment, Nigeria;
[2]. Ford 1987 noise sources and their measurement.
[3]. IFC. 2007, Environmental health and safety (EHS) guidelines.
[4]. ISO 1913.Physical methodology of noise measurements, international standard organization.
[5]. NESREA. 2009National Environmental (Noise Standards and Control) Regulations
[6]. NSW. 2000. New South Wales Industrial Noise Policy Published by Environment Protection Authority, 5961 Goulburn Street Sydney South NSW 1232; ISBN 0 7313 27152

ABSTRACT: There is an urgent need of clean, pure drinkable water. Often water sources are brackish and or contain harmful bacteria and therefore cannot be used for drinking. In this research work, proper selection of the type of solar water heater was made between the flat plate collector and evacuated tube collector type solar water heaters to construct a concrete cascade solar still hybrid system. The two types of solar water heaters were tested at the same time under the same metrological conditions. The results obtained shows that the evacuated tube collector type solar water heater with highest water output temperature of 97.2oC at 13:00 was for found to be the most suitable against the flat plate collector type solar water heater with 71.7oC at 14:00.

[1]. Dev R., Tiwari G. N. (2012). Annual performance of evacuated tubular collector integrated solar still. Desalination and water Treatment. 41(13):204-223.
[2]. Suraj, Y., Himanshu M., Mahesh K. and Rakesh K. (2017). Stepped and evacuated tube collector coupled solar stills: a comprehensive review. International journal of current engineering and scientific research.4(10). 62-71.
[3]. Patel M. I., Meena P. M. andInkia S. (2012) Effect of dye on distillation of a single slope active solar still coupled with evacuated glass tube solar collector. International Journal of Engineering Research and Applications.;1(3):456-460.
[4]. Karuppusamy S. (2012) An experimental study on single basin solar still augmented with evacuated tubes. Thermal science.;16(2):573-581
[5]. Yates R, Woto T, Thage JT. Solar Powered Desalination: A Case Study from Botswana Ottawa. International Development Research Centre (IDRC). 1990; 10(5): 11–16p.