http://cirworld.com/index.php/jap/issue/feed JOURNAL OF ADVANCES IN PHYSICS 2017-12-05T15:34:52+00:00 Chief Editor jap@cirworld.com Open Journal Systems scientific, open access, scholarly, peer-reviewed, fully referred international journal with DOI, ISSN ICV and IF http://cirworld.com/index.php/jap/article/view/6459 Non-Linear Abelian Scenarios and Yang-Mills Theory 2017-11-27T16:26:15+00:00 Saulo Machado Moreira Sousa salmac1010@gmail.com I. Soares salmac1010@gmail.com D. Leite salmac1010@gmail.com R. M. Doria salmac1010@gmail.com <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> 2017-11-27T16:26:15+00:00 ##submission.copyrightStatement## http://cirworld.com/index.php/jap/article/view/6436 Effect of rapid Solidification on mechanical properties of free machining lead free aluminum alloys for improved machinability 2017-12-01T01:56:07+00:00 Nermin Ali Abdelhakim drnerminsayed@yahoo.com Rizk Mostafa Shalaby drnerminsayed@yahoo.com Mustafa Kamal drnerminsayed@yahoo.com <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> 2017-12-01T01:56:07+00:00 ##submission.copyrightStatement## http://cirworld.com/index.php/jap/article/view/6113 The Influence of Fat Suppression Technique on Diffusion-weighted (DW) MRI in Lung Cancer 2017-12-05T15:34:52+00:00 Alexander Weller alweller@gmail.com MV Papoutsaki Vasia.Papoutsaki@icr.ac.uk M Orton Matthew.Orton@icr.ac.uk M Blackledge Matthew.Blackledge@icr.ac.uk D Ap Dafydd derfelapdafydd@hotmail.com C Kelly Moreland Christian.Kelly-Morland@rmh.nhs.uk Mary O’Brien Mary.O'Brien@rmh.nhs.uk V Morgan Veronica.Morgan@rmh.nhs.uk D Collins David.Collins@icr.ac.uk NM DeSouza Nandita.Desouza@icr.ac.uk <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> 2017-12-05T15:34:52+00:00 ##submission.copyrightStatement##