ISSN: 1817-2695

Volume 44, Issue 1

Volume 44, Issue 1, Autumn 2018, Page 1-132

Finite Volume and Finite Difference Numerical Methods for Conduction Heat Transfer via an Aluminum Rod

Journal of Basrah Researches (Sciences), Volume 44, Issue 1, Pages 1-10

The aim of this study is to investigate a conduction heat transfer phenomenon in Aluminum metal rod. Finite volume method has been used as a numerical technique to simulate the study in addition to finite difference method for more details. Both methods were compared to the exact solution which has been performed and utilized as a base line for the physical case in current study. Due to its widespread applications, Aluminum material has been used as a viable metal for the solid rod in this study. The Aluminum rod length and diameter were (10 cm) and (1 cm) respectively. The Aluminum rod has been set into a computational domain of air for the convection case to be taken into account. The computational domain of the air length and diameter were (12 cm) and (2 cm) respectively. The left side of the Aluminum rod has been set at temperature of (700 K) and the right side at (300 K). The surrounding computational domain of the air has been set at (300 K). Energy equation has been solved numerically to visualize and calculate the temperature distribution along the Aluminum rod. The results showed that there was good approach between finite volume and finite difference methods in one-dimensional temperature distribution. Hence, in addition to the fact that finite volume is crucial technique in all directions and used in more complicated applications, finite difference is still important method in one dimensional case as well. Moreover the results showed that volumetric heat source raises the temperature of the material during heat transfer operation. Also, the three methods, finite volume, finite difference and exact solution have showed good approach

Dielectric Behavior and Functionality of PVC / Cellulose acetate Composite

Journal of Basrah Researches (Sciences), Volume 44, Issue 1, Pages 20-32

Cellulose acetate powder which is extracted from the cigarette (insulator part as a filler) has been used with polymer to produce PVC Cement/cellulose acetate composite. The dielectric behavior of this composite is analyzed as a function of weight ratio of cellulose acetate powder (0.1, 0.2, 0.3, 0.4, and 0.5 wt%), temperature range (30 - 120) ◦C and frequency (120Hz 2MHz). Impedance and AC conductivity (ζac.) of the composites behaviors as function of frequency and temperature have also studied. The results show that, the real permittivity, dielectric loss and loss tangent for all composites increase the with increasing of cellulose acetate filler content

Diffraction ring patterns and z-scan measurements of nonlinear refractive index of khoba vegetable oil

Journal of Basrah Researches (Sciences), Volume 44, Issue 1, Pages 47-63

The estimation of the nonlinear refractive index of khoba vegetable oil via diffraction ring patterns and Z-scan using continuous-wave (CW) visible, a single mode low power laser beam, is reported. Diffraction ring patterns are numerically obtained using Fresnel-Kirchhoff diffraction integral with good agreement. The khoba oil exhibited strong self-defocusing effect and the mechanism of optical nonlinearity in the low power regime is found to be predominantly of thermal origin. The optical limiting properties of khoba oil under CW illumination is investigated. Based on the obtained results, the khoba vegetable oil can be considered as a potential candidate for the use in photonic and nonlinear optical devices

The Resonance Tunneling Process in the Scanning Tunneling Microscope with Carbon Nanotube as a Tip

Journal of Basrah Researches (Sciences), Volume 44, Issue 1, Pages 76-95

In our work we present an integrated calculation model to investigate the possibility of using carbon nanotubes as a tip for the scanning tunneling microscope. Our model takes into consideration the electronic properties of the substrate and tip that fabricated by using carbon nanomaterials . since we calculated the hybridization function and the quantum shift(as well as the assistant function) due to coupling between the molecule and the tip and the substrate . This calculation are utilized to calculate the local density of states on the molecule . We firstly studied the effect of all the properties of the carbon nanotube tip , since different carbon nanotubes chiral and achiral , metallic and semiconductor with different diameters are considered . Also , we calculated the transport properties for the used system (substrate - molecule – carbon nanotube tip) , these calculations can be considered as an additional step to enhance our results . We conclude that the carbon nanotube tip is not suitable for investigation in the most cases ,since that depends on the molecule effective energy level position with respect to the Van Hove (V.H) singularities in the electronic density of states of the carbon nanotube . And as the normal distance between the tip and the molecule is one of the most important experimental parameters that enhance the process of investigation , the effect of the tip distance on the process of investigation is studied for the carbon nanotube (12,0) . According to our calculations , it's concluded that it is possible to get the exact density of states by controlling the distance which is a function of the molecule effective energy level position .

Mutual Coupling Reduction In Microstrip Antenna Array Using Ebg

Journal of Basrah Researches (Sciences), Volume 44, Issue 1, Pages 122-132

Microstrip antenna array can be used for various application at X and KU-bands . In this paper the design of a microstrip antenna array configurations was 1x2 at 9.46 GHz were presented. A mutual coupling reduction method between closely spaced antenna array elements is proposed by using Electromagnetic Band Gap with T-Shaped slot (EBGT) and with T and L slots (EBGTL) . The simulated results shows that the good performance of antenna array by using EBG structure comparison with the antenna array without the decoupling structures. The mutual coupling in antenna array reducing to -56.83 dB by with EBGT and to -69.26 dB with EBGTL , and the average gain is 9.05 dB , and 9.65 dB with EBGT and EBGTL respectively

Some electronical properties for Coronene-Y interactions by using density functional theory(DFT)

Journal of Basrah Researches (Sciences), Volume 44, Issue 1, Pages 11-19

Density functional theory with hybrid functional (B3LYP) and the basis set 3-21G have been used to investigate the molecular structure for Coronene and Coronene-Y molecules through the geometrical optimization in which (Y=Al, B, C, Ga, In, O). New peaks demonstrate when Y atoms interact with Coronene because new bonds generate between Coronene and Y atoms. Interaction between Coronene and Y atoms lessen the ionization potential but enlarge the electron affinity. Coronene behaves as a donor in Coronene-Y, except Coronene-O. Energy gap becomes similar to semiconductors in Coronene-B and Coronene-C. Coronene behaves as a hard base when interacting with Y atoms. Coronene-In is the most polarizability molecule among all. Coronene-C and Coronene-O are like anti-ferromagnetic materials

Annealing Temperature Dependent Structural, Optical and Electrical Properties of Thermally Deposited CdSe Thin Films

Journal of Basrah Researches (Sciences), Volume 44, Issue 1, Pages 33-46

CdSe thin films have been deposited on suitably cleaned glass substrates by thermal evaporation method. The pressure during evaporation was maintained at 10-6 to 10-5 Torr. The samples are annealed in vacuum for 2h at various temperatures and characterized by structural, optical and electrical properties. The crystal structure and lattice parameter of these films were determined from X-ray diffractograms. It was observed that the films have a polycrystalline hexagonal (wurtzite) structure with preferred orientation along (002) plane. The crystallite size, dislocation density and micro strain were calculated by considering high intense diffraction peaks of the as-deposited and annealed films. It was found that the average size of the crystallites increases and the average dislocation density decreases with increasing annealing temperature. Absorption and transmittance spectra of these thin films were studied using UV-visible double beam spectrophotometer in the wavelength range of 300 – 1100 nm. The energy band gaps have been determined using absorption spectra. The values of the optical band gap energy, Eg, decreased from 2.37 – 2.08 eV with increasing the annealed temperature. Dependence of optical band gap on crystallite size has also been studied. The electrical resistivity and activation energy of CdSe thin films are calculated by two probe resistivity measurements. The decrease in dc resistivity with increase the grain size was also noted.


Journal of Basrah Researches (Sciences), Volume 44, Issue 1, Pages 64-75

The structure of the exotic light nucleus 36P is studied by using proton-neutron Tamm-Dancoff Approximation (pnTDA), where the neutron particle occupies the 2p-1f shells, and the proton hole occupies the 1s-1p, 1d5/2 and 2s1/2 shells. The configurations of one neutron particle- one proton hole are mixed in the presence of Modified Surface Delta Interaction (MSDI), and diagonalized to produce the best values of negative parity 36S, are calculated and compared with the available data. It found necessary introduce the to enhance the calculated log ft values

Evaluation of groundwater quality and the hydrogeochemical processes of shallow Dibdibba aquifer in Basra Governorate, southern Iraq

Journal of Basrah Researches (Sciences), Volume 44, Issue 1, Pages 96-121

Thirty seven groundwater samples were taken from groundwater wells to evaluate the groundwater quality of shallow Dibdibba aquifer at Safwan-Zubair area in Basrah governorate.
The physiochemical parameters were analyzed including pH, total dissolved solids (TDS), electrical conductivity (EC), the cations and anion elements. The results show that 81% and 19% of the studied samples are within (CaCl and NaCl) water type respectively. The results show that the middle and southern parts of the study area have the largest concentration of the most chemical and physical characteristics indicating increasing in it is agricultural and domestic activities.
The geochemical evaluated of the groundwater samples results show that 83.7% represented by probable mixing water affected by dissolution depended on Durov diagrame. All the studied samples were considered unsuitable for drinking purposes because of high total dissolved solids ranged between (2704 to 10322 mg/l). The groundwater samples were considered as unsuitable for irrigation because of higher concentration of Sodium adsorption ratio (SAR), Sodium percentage (Na%), Permeability index (PI), Magnesium ratio MR and Residual sodium bicarbonate (RSBC)