IOSR-JAP   Volume-7 ~ Issue-4 ~ July-August 2015

ABSTRACT: Despite the continuously increasing use of mobile phones and the consequent proliferation of GSM antenna masts, few studies on the health effects of the radiofrequency (RF) radiation from the antennas have been carried out in Nigeria and none in Ado-Ekiti, Nigeria. A baseline RF radiation assessment survey of thirty base stations was carried out in Ado-Ekiti to assess the level of radiofrequency pollution from their antennas. Power density measurements were undertaken using a calibrated Spectrum Analyzer.

[1]. O.A.Babatunde, B.T.Eguma, O.C.Igwilo, O.G.Awosanya, and O.Adegbenro. Mobile Phone Usage and Battery Disposal in Lagos, Nigeria. International Journal of Applied Psychology 4(4), 2014, 147-154.
[2]. S.Sivani, D.Sudarsanam. Impacts of radio-frequency electromagnetic field (RF-EMF) from cell phone towers and wireless devices on biosystem and ecosystem – a review. Biology and Medicine, 4 (4), 2012, 202–216.
[3]. ICNIRP. Guidelines for limiting exposure to time-varying Electric, Magnetic and Electromagnetic Fields (up to 300GHz). Health Physics 74(4), 1998, 494-522.
[4]. H. Cember. (Introduction to Health Physics: 4th Ed, 2009,New York: McGraw Hill).
[5]. A.A.Ayeni, K.T.Braimoh, O.B.Ayeni. Effects of GSM Phone Radiation on Human Pulse Rate (Heartbeat Rate). Journal of Emerging Trends in Computing and Information Sciences, 2(1), 2011, 580-587.

ABSTRACT: Nano crystalline Cu Substituted Mg-Zn ferrites having nominal compositional formula Mg0.2CuxZn0.8-xFe2O4 ranging from x=0.0 to 0.8 with step increment of 0.2 were synthesized by citrate gel auto combustion method using nitrates of respective elements, citric acid as a fuel and by keeping 1:1 ratio of metal nitrates to citric acid. The synthesized powders of the investigated samples were sintered at 500oC for 4 hours. X- ray diffraction patterns of all the investigated samples confirmed the single phase spinel structure which indicates the solubility of cations into their respective lattice sites.

[1] M. Siva Ram Prasad, B. Rajesh Babu, K.V. Ramesh, K.Trinath, J Supercond Nov Magn DOI 10.1007/s10948-014-2637-6
[2] Pankov, V.V. Pernet M, Germi P, Mollard. P, J of Magn and Magn Materials, 120,69 (1993).
[3] I.Soibama, S.Phanjobama, C.Prakash, J of Alloys and Compounds 475 (2009) 328-331
[4] I.H.Gul, A.Z.Abbasi, F.Amin, M.Anis-ur Rehman, A.Maqsood, J Of Mag Mag Mat 311 (2007) 494-499
[5] M.A.Gopal, Material Research Bullitin 45 (2010) 589-593
[6] A.Pradeep, P.Priyadarshini, G.Chandrashekaran, J of mag Mag Mat 320 (2008)
[7] G.Aravind, D.Ravinder, V.Nathanial, Physics Research International, Haindawi Publication Volume 2014, Article ID 672739,11
pageshttp://dx.doi.org/10.1155/2014/672739

ABSTRACT: Thin films of Barium Sulphide semiconductor were deposited on glass substrate using Chemical Bath Deposition Technique. The films were optically characterized using Camspec M501 Single Beam Scanning UV/VIS Spectrophotometer. The results show that films exhibited poor absorbance and reflectance properties with values range of 0.002-0.065 and 0.002-0.0.070 respectively. The transmittance of the films to the incident radiation was found to be high with a value range of 0.950-0.993 in arbitrary unit. The films were found to possess high optical conductivity of 7.43 x 1010S-1 – 5.52 x 1012S-1, and the films thickness found to increase as the dip time increases with value range of 1.668μm – 1.775μm.The calculated refractive index was found to be within the range of 1.132-2.205 and with low extinction coefficient value of 0.00159-0.00517. The band gap energy of the deposited films was found to be 1.25-1.35eV.

[1]. Kelin D.L., Roth R., Lim A.K.L., Alivisatos A.P., and McEuen, P.L.,(1997): Nanogap resistance random acess memory based on Natural Aluminium Oxide, Nature, 389, 699
[2]. Colvin V.L., Schlamp, M.C. and Alivisatos, A.P.,(1994): Light emitting diodes made from Cadmium Selenide, Nature., 370, 354
[3]. Onyia A.I. and Okeke C.E. (1989) : Fabrication and Characterization of tin oxide (SnO2) thin films using simple glass spray system , J.Phys D: Appl Phys., 22, 1515-1518
[4]. Engelken R.D. , McCloud H.E.,(1985): J. Electrochem. Soc. 132(3) 567
[5]. Zhuge F., Li X., Gao X. Gan. X, Zhou F.(2009): Mater. Lett. 63, 652
[6]. Anuar K., Zainal Z., Hussein M.Z., Saravanan, Haslina I., (2002): Sol. Energy Mater.Sol. Cells 73, 351
[7]. Nnabuchi M.N. (2006): J.Res.Sci., 17(4), 263-271

ABSTRACT: The electric field strength values of the transmitters of the Ondo State Radiovision Corporation (OSRC), Akure (CH 23, 487.25 MHz); OSRC, Oka Akoko, (CH 25, 503.25 MHz); and OSRC, Okitipupa, (CH 27, 519.25 MHz); were measured radially along several routes with the transmitting stations as references using a digital signal level meter. A hand held Global Positioning System (GPS) receiver was used for determining the geographic coordinates as well as the line of sight of the various data points from the base stations. Data were taken across the eighteen Local Government Areas of the State as far as road accessibility permits using a field vehicle with the receiving antenna attached. Data obtained were used to determine and classify the various grades of coverage as well as the towns and villages within the coverage zones. Surfer 8 software was used to generate the contour maps of the electric field strength of the signals over the Landmass. Coverage areas of 50.5%, 9.0% and 8.0% were determined for UHF Channels23, 25 and 27 respectively.

[1]. Ajayi G. O. And Owolabi I. E.: CoverageArea of the 10kW, 702kHz Medium Wave Transmitter at Minna and Feasibility Studies for full Radio Coverage of Niger State. Technical Report of the Electrical Communication Consultancy Unit (ECCU), Department of Electrical and Electronics Engineering, University of Ife, Nigeria.
[2]. Ajewole, M.O (2011): Radio and Rain: Friends and Foes" An inaugural lecture delivered at the Federal University of Technology, Akure, Nigeria, pp 23-25
[3]. Ajewole, M.O, Oyedun, O. D, Adediji, A. T, Eichie, J. O and Moses, A. S (2012): Spatial Coverage of FM Radio Transmitters in Niger State, Nigeria:IUP Journal of Telecommunications, Vol. iv, No. 4, 2012, Pp7-19.
[4]. Ajewole, M.O, Oyedun, O. D, Adediji, A. T, Moses, A. S, and Eichie, J. O (2013): Spatial Variability of VHF/UHF Electric Field Strength in Niger State, Nigeria, International Journal of Digital Information and Wireless Communications Vol. 3(3), pp26-34.
[5]. Akinbolati, A (2012): "Survey of Electric Field Strength and Path Loss Prediction of UHF Television Signals in Ondo State, Nigeria".

ABSTRACT: Glasses with the composition xCaO-15ZnO- 20Bi2O3- (64−x) B2O3- 1EuO [where x= 0, 5, 10, 15, 20 mol %] were prepared by the conventional melt quenching technique. X-ray diffraction studies, the differential scanning calorimetry (DSC), density of the samples were carried out. Molar volume was calculated from the density data, and the physical properties were calculated using density, refractive index. The optical absorption spectra in UV-Vis region were recorded in the wave length range 200-1000nm. Cut-off wavelength, direct, indirect band gap, Urbach energy, Molar refraction (Rm), Molar electronic polarizability (αm), reflection loss and refractive index values were evaluated from absorbance data The structural changes in the boron and bismuth co-ordination with incorporation of alkaline earth oxide variations and rear earth (EuO) doping were investigated by FT-IR spectroscopic techniques.

[1] C.R. Kesavulu, K. Kiran Kumar, N. Vijaya, Ki-Soo Lim, C.K. Jayasankar, Materials Chemistry and Physics 141 (2013) 903e911

[2] D. Ruter, W. Bauhofer, Appl. Phys. Lett. 69 (1996) 892.

[3] D.A. Turnbull, S.Q. Gu, S.G. Bishop, J. Appl. Phys. 80 (1996) 2436.

[4] P.E.A. Mobert, E. Heumann, G. Huber, B.H.T. Chai, Appl. Phys. Lett. 73(1998) 139.

[5] S. Schweizer, L.W. Hobbs, M. Secu, J. Spaeth, A. Edgar, G.V.M. Williams, Appl.Phys. Lett. 83 (2003) 449.

ABSTRACT: Different zinc oxide (ZnO) nanostructured thin films were grown on glass substrates at low temperatures by combining successive ionic layer adsorption and reaction (SILAR) method and chemical bath deposition (CBD). Morphologies and structures of the samples were investigatedby X-ray diffraction (XRD), energy-dispersive x-ray spectroscopy (EDX) and scanning electron microscopy (SEM). The reaction mechanism for the growth of ZnO microstructures is analyzed. The results show that the surface morphology of the ZnO nanostructures films changed from hexagonal nanorods into hexagonal nanodisc with increasing the growth time ofZnO. According to XRD.

[1]. J. Hupkes, B. Rech, S. Calnan, O. Kluth, U. Zastrow, H. Siekmann, and M.Wuttig, Material study on reactively sputtered zinc oxide for thin filmsilicon solar cells, thin solid films journal,502 (1),2006, 286–291.
[2]. C. Ying Lee, S. Yi Li, P. Lin, and T.Yuen Tseng, Field-emission triode of low temperature synthesized ZnO nanowires, IEEE Transactions on Nanotechnology, 5(3),2006,216–219.
[3]. S. Yi Li,P.Lin,C.Ying Lee, and T.Yuen Tseng, Field emission and photofluorescent characteristics of zinc oxide nanowires synthesized by a metal catalyzed vapor–liquid–solid process, Journal of Applied Physics, 95(7),2004 ,3711–3716.
[4]. S.N. Bai, T.Y. Tseng, Effect of alumina doping on structural, electrical,and optical properties of sputtered ZnO thin films, thin solid films Journal, 515(3),2006, 872–875.
[5]. Z. L. Wang, Nanostructures of zinc oxide,MaterialsToday, 7(6),2004.,26–33 .

ABSTRACT: Single crystals of Beta Alanine Thiourea Oxalate (BATO) were grown by slow evaporation solution growth method. The crystal structure was found to be monoclinic according to single crystal X-ray diffraction studies. Sharp peaks appeared in the powder X-ray diffraction pattern proved the good crystalline nature of the sample. FTIR spectral analysis revealed the possible functional groups and modes of vibration. Optical parameters such as refractive index , extinction co-efficient , optical absorption co-efficient , optical conductivity , electrical conductivity and electrical susceptibility of the grown crystal were calculated from UV-Vis-NIR spectral studies.

[1]. J.C.Brice.,(1986)Crystal growth processes,(ISBN 0470202688),Blackie(Glasgow and New York),298.
[2]. D.S.Chemla, J,Zyss,(1987) ,Nonlinear optical properties of organic molecules and crystals, Academic press,1:2
[3]. R.T.Bailey, F.R.Cruickshank,D.Pugh,J.N.Sherwood ,(1991), growth perfection and properties of organic nonlinear molecules ,Acta Crystallographica,A ,47:145-155
[4]. J.Thomas Jeyaprakash,L.Ruby Nirmala(2011), Synthesis spectral and thermal properties of bisthiourea zinc acetate single crystals, International journal of computer applications, Vol.6,0975-8887..
[5]. M.Subanandhini ,R.V.Krishnakumar ,M.Sivakumar,S.Natarajan ,9(2002),Crystal structure of beta alanine complex materials ,Acta Crystallographica E 58-307

ABSTRACT: Amorphous Ge20BixSe80-xthin films have been prepared on glass substrates by vacuum deposition. This system is promising candidate for application as a new generation of p-n junctions. Measurements of optical spectra; reflection and transmission during visible to near infrared region; as function of composition were done. The composition of the system was checked by EDAX. HR-Transmission electron microscope patterns, morphology and electron diffraction were introduced. The optical constants like the energy gaps were calculated and found to range from 0.36 e.V to 1.73 e.V. The energy gaps decreases via increasing thicknesses hence they fulfill the quantum size effect. The effect of Bi content on the energy gaps "Eg" is that it decreases with increasing Bi content.

[1]. Trone, P.; Bensoussan, M. ; Brenace, A. Phys. Rev. B, 1973, 8,5947.
[2]. Frumar, M.; Tichy, L. J. noncryst. Solids, 1987, 97/98, 1139.
[3]. Tonge, N.; Minami, T.; Tanaka, M. J. Noncryst. Solids 1980,37, 23.
[4]. Tohge, N.; Matsuo, H.; Tanaka, M. J. Noncryst. Solids 1985,96, 809.
[5]. Tohge, N.; Minami,T.; Tanaka, M. J. Noncryst. Solids 1980,38/39 283.