English Articles

Comparison between Viscosity and Surface Tension of Polyvinylpyrrolidone/ Silver Nanoparticle (PVP/ AgNP) Solutions and Polyethylene Glycol/ Silver Nanoparticle (PEG/ AgNP) Solutions
 

In the present study, viscosity and surface tension of Polyvinylpyrrolidone (PVP) solutions and Polyethylene glycol (PEG) solutions in water and nitric acid with different concentrations (0.0, 0.2, 0.4, 0.6, 0.8 and 1.0 %) of silver nanoparticles have been measured. However, the relative viscosity of PVP/ AgNP solutions increased from 2.245 to 2.585 and the relative viscosity of PEG / AgNP solutions increased from 1.150 to 1.204. Viscosity is a significant parameter during the electrospinning process. While the surface tension of the PVP/ AgNP solutions has changed from 0.052 Nm^-1 to 1.46 Nm^-1, it has changed from 0.063 Nm^-1 to 0.160 Nm^-1 for PEG / AgNP solutions. In this paper, attempts were made to obtain improvements to the properties of samples by comparing them with the pure samples of polymers. I think that there are personal errors in the measurements. These results can be used in medical, industrial applications and in scientific studies.

Najla Ali Elgheryani

Solutions of the Dirac Equation for the Quadratic Exponential-Manning-Rosen Potential plus Yukawa Potential within theYukawa-like Tensor Interaction using the Framework of Nikiforov-Uvarov Formalism

Here, we solve the Dirac equation for the quadratic exponential-type potential plus Manning-Rosen potential including a Yukawa-like tensor potential with arbitrary spin-orbit coupling quantum number κ. In the framework of the spin and pseudo-spin (pspin) symmetry, we obtain the energy eigenvalue equation and the corresponding eigenfunctions in closed form by using the Nikiforov–Uvarov method. Also, special cases of the potential have been considered and their energy eigenvalues as well as their corresponding eigenfunctions were obtained for both relativistic and non-relativistic scope.

Hitler Louis,

Ita I. Benedict,

Nzeata I. Nelson,

and

Ike V. Chidinma
 

Basic Concepts and Development of Dry Deposition Modelling

Dry deposition is the primary mechanism by which suspended particles are transported from gas onto surfaces. Prediction of this transport rate represented by the dry deposition velocity (V_d) is needed in a vast range of applications, such as atmospheric climate and air quality models, industrial processes, nanomaterials, clean rooms, building engineering, particle losses inside sampling lines, health effect of atmospheric particles and pharmaceutics. The particle transport rate towards the surface depends on many factors: above-surface air flow and fluid characteristics, physical characteristics of the particles and surface properties. Although dry deposition models have been improved significantly, they still need to be further developed to improve the model accuracy and include weak mechanisms of particle transport. In general, a dry deposition model incorporates Fickian diffusion (Brownian and Eddy) and gravitational settling. Turbophoresis was introduced to compensate for the enhancement in V_d as a result of inhomogeneous turbulent mixing. In real-life conditions, electrophoresis and thermophoresis are not strong enough mechanisms to be included in model calculations, but for some applications (such as air purifiers), these transport mechanisms are very important to be considered in model formulation. Magnetophoresis, which is a very weak mechanism in real-life conditions, can be enhanced for certain industrial applications. In general, deposition surfaces are rarely smooth and researchers have put great efforts to describe surface roughness in dry deposition models. After all, a unified dry deposition formulation is needed to be developed/ improved in the future to make dry deposition prediction and calculations easier and more accurate. In this paper, we present the basic concepts that have been developed and implemented in dry deposition models and illustrate the effect of different processes on the transport rate of suspended particles in the fluids towards surfaces. As a benchmark for the accuracy of the current dry deposition modelling, we present a comparison between model calculations and experimental data-bases found in the literature.

Tareq Hussein,

Safa’ Ibrahim

and

Sawsan Malek

Structural, Spectroscopic and Magnetic Characterization of Bi_0.9X_0.1Fe_0.98Mg_0.02O₃ (X = Gd, Sm, Ba) Multiferroic Compounds

The compounds Bi_0.9Gd_0.1Fe_0.98Mg_0.02O₃, Bi_0.9Sm_0.1Fe_0.98Mg_0.02O₃ and Bi_0.9Ba_0.1Fe_0.98Mg_0.02O₃ were found to have a rhombohedral perovskite-like structure. The structural parameters were extracted from the X-ray diffraction data. Fourier transform infrared spectroscopy revealed traces of the a-Fe₂O₃ magnetic phase in the Bi_0.9Ba_0.1Fe_0.98Mg_0.02O₃ compound. The Bi_0.9Gd_0.1Fe_0.98Mg_0.02O₃ and Bi_0.9Sm_0.1Fe_0.98Mg_0.02O₃ compounds were found to show a weak intrinsic ferromagnetic behavior, whereas the ferromagnetism of the Bi_0.9Ba_0.1Fe_0.98Mg_0.02O₃ compound was found to be non-intrinsic in origin. The magnetic transition temperatures were found to be around 340 °C.

Mansour M. Al-Haj

Structural and Magnetic Properties of La_2/3D_1/3MnO₃ (D = Ca, Sr, Ba) Manganites Prepared By Ball Milling

Sami Mahmood,

Haneen Badran,

Eman Al-Hwaitat,

Ibrahim Bsoul

and

Rola Bqaeen

Natural and artificial radioactivity levels in surface soil samples collected from various sites in Tafila governorate in Jordan, have been determined using gamma-ray spectrometry. The average concentrations of ²³⁸U, ²²⁶Ra, ²³²Th, ⁴⁰K and ¹³⁷Cs were 23.6 ± 3.1, 23.3 ± 0.7, 16.7 ± 1.0, 234.1 ± 9.85 and 5.4 ± 0.3 Bq kg^-1, respectively. The activity ratio between ²³⁸U and ²²⁶Ra for all samples was close to unity. The average values of radium equivalent activity, gamma-absorbed dose rate in air, annual effective dose equivalent, external hazard index, internal hazard index and excess lifetime cancer risk were 65.2 Bq kg^-1, 30.6 nGy h^-1, 37.6 µSv y^-1, 0.18, 0.24 and 1.3910^-4, respectively. These values for the collected samples do not exceed the permissible limits. Therefore, the studied area does not pose any significant radiation hazard to the public. Furthermore, it has been found that the activity concentration of ¹³⁷Cs radionuclide is within the values of recommended safe levels.

Ahmad M. Al-Qararah,

Abdallah H. Almahasneh,

Derar Altarawneh

and

Alaa Jaffal
 

 JJP, 2019, 12(2), 153-161

Classification of LRS Bianchi Type I Spacetime through Its Conformal Killing Vector Fields

In this paper, we investigate Conformal Killing Vector Fields (CKVFs) of Locally Rotationally Symmetric (LRS) Bianchi type I spacetime. Ten conformal Killing equations and the CKVF components having unknown functions of integration are derived. Specific solutions of these conformal Killing equations are subject to the twelve integrability conditions. Integrability conditions are solved completely in different cases and CKVFs of dimensions four, five and six are obtained along with their conformal factors. In each case, the exact form of the metric which admits CKVFs is obtained. The inheriting CKVFs are obtained. It is also shown that a particular vacuum solution of LRS Bianchi type I spacetime does not admit proper homothetic or proper CKVF.

Suhail Khan,

Syed Zaheer Ullah,

M. Ramzan

and

Muhammad Ayaz

Wireless Electricity Transmission by Coupled Magnetic Resonances

In this work, we have experimentally demonstrated the ability of transferring electrical power wirelessly using coupled magnetic resonance technique. This technique has been improved by using four resonators, thus maintaining the efficiency of transferring electricity wirelessly during the change of the transfer distance between the transmitter and the receiver coils. We also introduce the concepts of this technique, analyze the used circuit and extract the theoretical model which agrees with experimental results. We have experimentally measured the efficiency of transferred electricity at various transfer distances beginning from 30 cm to 130 cm. The efficiency was more than 50% at a distance of less than 70 cm and 22% at a distance of 100 cm.

DaifAoulah Nassor,

Ali Daroesho

and

Abdalrahaman H. Alhashim

Radiological Characterization of Settled Dust during a Severe Dust Episode in Jordan

An unusually massive dust storm influenced Jordan and neighboring countries on September 8^th to 11^th 2015. The dust from this storm was investigated for its radioactive content using gamma-ray spectroscopy. Such storms may carry a large amount of dust and radioactive content, which may impact human health. Samples were collected from different regions in Jordan. The activity concentrations of natural ²³²Th (Thorium), ²³⁸U (Uranium), ⁴⁰K (Potassium) and artificial ¹³⁷Cs (Cesium) radionuclides were measured. The activity concentrations (Bq kg^-1) had an average of (± Standard Deviation (SD)) 24.7 ± 10, 34.1 ± 13.3, 438 ± 124 and 15.7 ± 4.1 for ²³²Th, ²³⁸U, ⁴⁰K, and ¹³⁷Cs, respectively. The activity concentrations of natural and artificial radionuclides were analogous with results obtained from different studies with seasonal storms. The natural radionuclides were comparable to what was found in the local soil, while the activity concentration of ¹³⁷Cs was larger than that found in soil (2.4 ± 1.2 Bq kg^-1) and this is attributed to particle size effects. Dose assessment of ¹³⁷Cs showed that it does not contribute significantly to the internal dose of a human during inhalation. The correlation between ²³²Th and ⁴⁰K activity concentration in the measured dust particles is a moderate correlation with a value which is in agreement with those found in other studies worldwide.

Manal J. Abdallah,

Molham M. Eyadeh,

Hamed H. Hamadneh,

Abdulrahman N. Akour,

Mustafa M. Hawamdeh

and

Ibtisam F. Almaaitah