English Articles

Effect of Substrate Temperature on Optical Properties of Spray Pyrolytic Cadmium Sulphide Thin Films
 

Cadmium sulphide (CdS) thin films were prepared by chemical spray pyrolysis technique on micro-slide glasses using cadmium acetate and thiourea as precursors. The substrate temperature was varied in the range of 250°C- 350°C. The prepared films were annealed at 500°C for 1hour. The effects of substrate temperature and annealing on the optical properties of the films were investigated. The films were characterized using UV-Visible Spectrophotometer. The absorption and transmission spectra revealed that the transmission increases with wavelength, while the absorbance reduces as the wavelength increases in the visible region. The optical band gaps of the films were found to be 2.26eV, 2.07eV and 1.88eV with deposition temperature of 250°C, 300°C and 350°C, respectively. It was observed that the refractive index of the thin film obtained reduces as the substrate temperature increases and that annealing reduces the refractive index of the cadmium sulphide thin film. These findings show that cadmium sulphide is one of the most promising materials to be used as a window layer in hetero-junction thin film solar cells. It is also of good interest for its applications in some optoelectronic devices, like photoresistor and photodiode.

I. S. Akinsola,

A. B. Alabi,

A. A. Ajayi,

K. S. Adedayo and O. A. Babalola

Density and Surface Tension of Propanol and Propanol-Water Mixtures Using Molecular Dynamic Simulations

Optimized Potentials for Liquid Simulations-All Atoms (OPLS-AA) and Transferable Potentials for Phase Equilibria-United Atom (TraPPE-UA) have been examined with two water models (TIP4P and SPC/E) to estimate the density and the surface tension for unary propanol and binary propanol-water mixtures. While both models predicted the experimental trend of the density for the unary system as a function of temperature and for the binary mixtures as a function of mole fraction of propanol, TraPPE-UA shows better fit with experimental data of pure propanol at low temperatures range (200K-300K). On the other hand, for the surface tension, TraPPE-UA provides a better agreement with the experimental data for pure propanol, while OPLS-AA shows better agreement for the binary mixtures at 300K for the entire mole fraction of propanol (0-1). The density profiles of the mixtures show that the structure of the mixtures changes from core-shell at low mole fractions of propanol to well-mixed at high concentrations of propanol.

K. A. Khasawneh ,

M. M. Al-Ali,

R.M. Al-Salman,

H. A. Abu-Ghazleh and A. A. Obeidat
 

Simulation-Assisted Environment-Mapping Using Unidirectional Ultrasonic Pulses

In this paper, a new system for mapping and discovering an environment using simple ultrasound transceivers, connected to a microcontroller, is developed with the aid of an ultrasonic wavelet propagation simulation program. Environment mapping is achieved by sending ultrasonic pulses with known characteristics and listening to the reflections from all directions in real time. The change induced in the shape of a pulse wavefront due to reflection is found to be dependent on the barriers in the environment and on its geometry. The correlation between the changes in the shapes of the wavefronts and the shapes of the reflecting objects is investigated. This includes the slope or curvature of the reflecting wall (or barrier), wall tilt or angle and possible twists in corners. By analyzing the interference patterns and counting the interference fringes in the reflected pulses, a method for measuring object orientation is developed. The presented technique can also discover unseen objects behind corners. The results obtained show that this method is not only effective in discovering an environment, but also in measuring subtle features, such as the rotation of an object with an accuracy of 0.1^◦. The mapping and discovery techniques described in this paper are targeted for artificial intelligence applications and robotics. The infinite number of possibilities in the reflected wavefront characteristics, due to the similarly infinite environment shapes, makes experimentally collecting this data impossible. The simulated data presented in this paper will take more than six months to be collected experimentally.

M. Al-Shorman,

M. Al-Kofahi and

Q. I. Mohaidat

The Collision-Induced Absorption Spectra of Hydrogen Complexes in the Second Overtone Band

The second overtone band (3-0) of pure hydrogen spectra at different temperatures and hydrogen gas densities is reviewed with particular emphasis on the most recent theoretical and experimental results. Different experimental and theoretical techniques were used to record and calculate the second overtone band profiles. The calculated theoretical binary and ternary absorption coefficients are in good agreement with experimental values obtained. Different line shapes were used to fit the experimental profiles. The fitting values are tabulated in the references therein. The goal of this article is to draw the attention of the absorption spectroscopy community to the fact that there have been only a few investigations on the latter subject on the second overtone band (3-0) on hydrogen, even though the investigations on the other bands are quite abundant.

M. Abu-Kharma,

Mahmoud H. Saleh,

Z. M. Elimat and

W. J. Kadhem

Estimation of Radionuclide Concentrations and Average Effective Dose from Some Selected Imported Foodstuff

Radionuclide concentrations in imported food products depend on the geological and mineralogical characteristics of the soil from which the products are derived and this is a major cause of concern in radiation monitoring. The analysis of three naturally occurring radionuclides that are: ²²⁶Ra, ²³²Th and ⁴⁰K in fourteen selected imported food samples was carried out in this research using sodium iodine detector. Reasonable quantities of each of the samples were packed in cylindrical containers and kept for a month to attain secular equilibrium. The activity concentrations of the analyzed samples ranged from 48.76 ± 5.03 to 85.45 ± 3.20, from 10.10 ± 1.70 to 21.10 ± 2.20 and from 8.06 ±1.4 to 10.54 ± 3.64 Bq/kg and their average values were 65.32 ± 4.14, 11.23 ± 2.18 and 9.68 ± 2.08 for ⁴⁰K, ²²⁶Ra and ²³²Th, respectively. For ²³²Th, ten samples were seen to be below detention limit BDL. The mean effective dose was estimated to be 4.17 µSv/y. The result of the radiation dose was less than the average value of 1mSv/y for general public, making the foodstuff analyzed radiologically safe for consumption.

A. B. Ogunremi and

K. A. Adewoyin

In the present paper, the structural and electronic properties have been studied with the help of thermodynamic parameter. The lattice parameter and nanoparticle size in lead chalcogenides [(PbX, X = S, Se and Te)] are calculated with the help of fitting parameter under the effect of temperature. The calculated values are in close agreement with the experimental results.

D. R. Adhikari,

S. K. Adhikari and

H. P. Lamichhane
 

 JJP, 2019, 12(3), 241-245

Magnetization and Magnetic Susceptibility of GaAs Quantum Dot with Gaussian Confinement in Applied Magnetic Field

We present a theoretical study of the magnetization (M) and the magnetic susceptibility ( of single electron Gaussian quantum dot (GQD) presented in a magnetic field. We solve the Hamiltonian of this system including the spin by using exact diagonalization method. All the energy matrix elements are obtained in closed analytic form. We investigate the effects of temperature, magnetic field and confining potential depth on the behavior of magnetization and magnetic susceptibility of the quantum dot. Comparisons show that our results are in very good agreement with reported works.

M. Ali,

M. Elsaid and

A. Shaer

JRTR, the First Research Reactor in Jordan: Results of Commissioning in Light of Safety Enhancement Following Fukushima-Daiichi Accident

The Jordan Research and Training Reactor (JRTR) is a multipurpose, 5 MWth upgradable to 10 MWth reactor. Currently, the JRTR is in the operational phase. Prior to the start of JRTR operation, a set of commissioning tests have been performed. The IAEA safety guide NS-G-4.1 has been followed. The commissioning process was divided into three main stages with hold points at the end of each stage. These stages are; tests prior to fuel loading, fuel loading tests and initial criticality tests which include low power tests. The last stage constitutes power ascension tests and power tests up to rated full power. The performed tests proved that all design and performance parameters have been achieved. For instance, the thermal power of 5 MW, maximum thermal neutron flux of 1.5 ×10¹⁴ (n/cm².s) and negative reactivity feedback have been achieved. The safety of the JRTR was under extensive inspection from all involved parties. Particular attention has been paid to the lessons learned from the Fukushima-Daiichi accident and the recommendations made by the national regulator, the IAEA, the consultants and the owner. For instance, all safety aspects of the JRTR fall under the category of SC-3 according to the ANSI/ANS 51.1 classification system of nuclear reactors. ...

Khalifeh AbuSaleem

Discrimination of Aerosol Types over Nairobi, Skukuza and Ilorin Using AOD-AE Clusters

Climatology of aerosols, their trends and classification based on the long-term Moderate Resolution Imaging Spectroradiometer (MODIS) measurements (from February 2000 to July 2015) of aerosol optical depths at 550 nm (τ₅₅₀) and Angstrom exponent   (α_470-660) using the wavelengths of 470 and 660nm in Nairobi, Skukuza and Ilorin AERONET stations were analyzed in this work. The level-2 collection-6 Deep Blue (L2 C006 DB) of the parameters listed above from the aqua- (MYD04) and terra- (MOD04) MODIS of the study area were statistically analyzed using SPSS. To be able to understand the temporal variation in the characteristics of aerosols in the three stations and during each season separately, MODIS measurements of τ, retrieved for the study area, were compared with AERONET τ. Overall, aqua-MODIS τ corroborate the AERONET measurements well in Nairobi and Ilorin stations with underestimation of 29.80 % and overestimation of     2.90 % respectively, whereas Skukuza station has terra-MODIS τ as the best representation of the AERONET measurements with underestimation of 1.90 %. ....

S. B. Sharafa,

B. I. Tijjani,

R. Aliyu,

T. H. Darma,

H. T. Sulu and

M. M. Bube