JOURNAL OF ADVANCES IN PHYSICS scientific, open access, scholarly, peer-reviewed, fully referred international journal with DOI, ISSN ICV and IF en-US <p><a href="" target="_blank">Copyright Notice</a></p> (Chief Editor) (Editorial Support Team) Mon, 27 Nov 2017 16:24:34 +0000 OJS 60 Non-Linear Abelian Scenarios and Yang-Mills Theory <p>We present a natural formulation for constructing Yang-Mills theories from the incorporation of non-linearities to the Maxwell's theory of electromagnetism. Our formulation is strongly based on Noether's Theorem and aims to show how the introduction of non-linearities can turn a global invariance into a local symmetry as the more general Yang-Mills type of symmetry.</p> Saulo Machado Moreira Sousa, I. Soares, D. Leite, R. M. Doria ##submission.copyrightStatement## Mon, 27 Nov 2017 16:26:15 +0000 Effect of rapid Solidification on mechanical properties of free machining lead free aluminum alloys for improved machinability <p>There have been very few reports describing the free machining lead free aluminum alloys containing minimal amounts of tin and indium melt spun process. Our paper describes the effect of fundamental factors on the machinability of free machining lead free aluminum alloys rapidly solidified from melt. Structural and thermal properties have been investigated by x-ray diffraction (XRD) and differential scanning calorimetry (DSC) techniques. Tensile test machine used in studies the mechanical properties such as ultimate tensile strength, elastic constants, yield strength and critical shear stress for Al-Zn-Sn-In alloys. It is noticed that mechanical and thermal properties attributed to fine grained structure, reduced levels of segregation and presence of new intermetallic compounds (IMC) such as AlZn and SnZn due to high casting rate by rapid solidification processes. The determination of mechanical properties was suggested to be attributed to the gradual increase of α-Al crystals. We evaluated the tensile properties using tensile test machine of the melt-spun ribbons at varied stress-strain rates to determine the underlying deformation mechanisms .Critical shear stress (CSS) was also calculated .It was found that it is equal to 9.29 GPa for annealed ribbons at 262 <sup>0</sup>C for 9 hrs. The results showed that several combination of tensile strength ,yield strength ,elastic moduli can be generated from Al- 0.1wt% Zn-1.5 wt% Sn- 1.63 wt% In alloys before and after heat treatment at (262 <sup>0</sup>C for 3,6,9 hrs) to meet the needs of free machining aluminum alloy applications.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</p> Nermin Ali Abdelhakim, Rizk Mostafa Shalaby, Mustafa Kamal ##submission.copyrightStatement## Fri, 01 Dec 2017 01:56:07 +0000 The Influence of Fat Suppression Technique on Diffusion-weighted (DW) MRI in Lung Cancer <p>Purpose: To qualitatively and quantitatively investigate the effect of common vendor-related sequence variations in fat suppression techniques on the diagnostic performance of free-breathing DW protocols for lung imaging.<br>Methods: 8 patients with malignant lung lesions were scanned in free breathing using two diffusion-weighted (DW) protocols with different fat suppression techniques: DWA used short-tau inversion recovery (STIR), and DWB used Spectral Adiabatic Inversion Recovery (SPAIR). Both techniques were obtained at two time points, between 1 hour and 1 week apart. Image quality was assessed using a 5-point scoring system. The number of lesions visible within lung, mediastinum and at thoracic inlet on the DW (b=800 s/mm2) images was compared. Signal-to-noise ratios (SNR) were calculated for lesions and para-spinal muscle. Repeatability of ADC values of the lesions was estimated for both protocols together and separately.<br>Results: There was a signal void at the thoracic inlet in all patients with DWB but not with DWA. DWA images were rated significantly better than DWB images overall quality domains. (Cohen’s κ = 1). Although 8 more upper mediastinal/thoracic inlet lymph nodes were detected with DWA than DWB, this did not reach statistical significance (p = 0.23). Tumour ADC values were not significantly different between protocols (p=0.93), their ADC reproducibility was satisfactory (CoV=7.7%) and repeatability of each protocol separately was comparable (CoVDWA=3.7% (95% CI 2.5 – 7.1%) and CoVDWB=4.6% (95% CI 3.1 – 8.8%)).<br>Conclusion: In a free-breathing DW-MRI protocol for lung, STIR fat suppression produced images of better diagnostic quality than SPAIR, while maintaining comparable SNR and providing repeatable quantitative ADC acceptable for use in a multicentre trial setting.</p> Alexander Weller, MV Papoutsaki, M Orton, M Blackledge, D Ap Dafydd, C Kelly Moreland, Mary O’Brien, V Morgan, D Collins, NM DeSouza ##submission.copyrightStatement## Tue, 05 Dec 2017 15:34:52 +0000 Relationship between soil water content and crop yield under sahelian climate conditions: case study of Tougou experimental site in Burkina Faso <p>This study aims at assessing the relationship between soil water stock and the yield of agricultural practices in Tougou catchment located in northern Burkina Faso. It is a region that has experienced a significant and continuous degradation of its natural resources, especially soils, due to the climate variability and the rapid increase of the population. Areas allocated to subsistence agriculture are increasing at the expense of pastoral land. This degradation causes a change in processes and mechanisms that control ecological systems. In order to provide solutions to this issue, some agricultural practices have been implemented to improve crop yield. This is particularly the case of traditional techniques:“zaï”, “stony line” and “half-moon”, which can significantly improve the soil infiltration capacity and yield. Daily monitoring of soil moisture and pressure in experimental plots based on these agricultural practices show that half-moon and Zaï provided good yield with 2180kg / ha and 1070 kg / ha respectively compared to that of the control plot with about 480 kg/ha. These important yields are due in large part to the improvement of the retention capacity of these soils, thus giving to crops the necessary water need for their development even in drought periods</p> Cheick Oumar Zouré, Mahamadou KOITA, Dial Niang, Izza Issa Baba, Ousmane Roland Yonaba, Amagana Emmanuel Dara, Tazen Fowé, Pierre Queloz, Harouna Karambiri ##submission.copyrightStatement## Sat, 30 Dec 2017 02:20:36 +0000