3,050 research outputs found

    Second Order Corrections to QED Coupling at Low Temperature

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    We calculate the second order corrections to vacuum polarization tensor of photons at low temperatures, i.e; T 1010\le 10^{10} K (T<<meT << m_e). The thermal contributions to the QED coupling constant are evaluated at temperatures below the electron mass that is T<meT< m_e . Renormalization of QED at these temperatures has explicitly been checked. The electromagnetic properties of such a thermal medium are modified. Parameters like electric permittivity and magnetic permeability of such a medium are no more constant and become functions of temperature.Comment: 8 latex pages and 1 figure (to appear in IJMP

    Classification of colon biopsy samples by spatial analysis of a single spectral band from its hyperspectral cube

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    The histopathological analysis of colon biopsy samples is a very important part of screening for colorectal cancer. There is, however, significant inter-observer and even intra-observer variability in the results of such analysis due to its very subjective nature. Therefore, quantitative methods are required for the analysis of histopathological images to aid the histopatholgists in their diagnosis. In this paper, we exploit the shape and structure of the gland nuclei cells for the classification of colon biopsy samples using two-dimensional principal component analysis (2DPCA) and Support Vector Machine (SVM). We conclude that the use of textural features extracted from non-overlapping blocks of the histopathological images results in a non-linear decision boundary which can be efficiently exploited using a SVM with appropriate choice of parameters for its Gaussian kernel. The SVM classifier outperforms all the remaining methods by a clear margin

    English Competencies and Challenges for Data Science and Cyber Security Students at Al Istiqlal University

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    This present research aims to determine the growing needs and challenges faced by Data Science and Cyber Security students at Al Istiqlal University's Faculty of Information Technology when learning the English language. It also tries to ascertain whether gender and level of competence affected their requirements and difficulties in mastering the English language. 35 cadets who are specializing in Data Science and Cyber Security make up the sample. The researcher gave out 39 questionnaire items divided into eight domains. The results show that cadets in Data Science and Cyber Security did not undergo any guidance regarding how to utilize English in the discipline while engaging in the analysis of data or cyber security keywords. Additionally, the study demonstrates that cadets majoring in data science and cyber security did not receive any guidance on how to learn to communicate in English, and the teaching activities in the English programs they had taken did not match their notions of the standards for expert English. Moreover, English proficiency requirements for cadets enrolling in Data Science and Cyber Security courses should be taken into consideration. &nbsp;Additionally, no statically meaningful differences in the demands for key competencies and barriers faced by Data Science and Cyber Security cadets are found when gender and competency traits are taken into consideration

    4-(4-Nitrophenoxy)biphenyl

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    The two phenyl rings of the biphenyl unit of the title compound, C18H13NO3, are almost coplanar [dihedral angle 6.70 (9)°]. The nitrophenyl ring, on the other hand, is significantly twisted out of the plane of the these two rings, making dihedral angles of 68.83 (4)° with the middle ring and 62.86 (4)° with the end ring. The nitro group is twisted by 12.1 (2)° out of the plane of the phenyl ring to which it is attached. Key indicators: single-crystal X-ray study; T = 173 K; mean &#963;(C–C) = 0.002 A° ; R factor = 0.040; wR factor = 0.118; data-to-parameter ratio = 12.8

    Manifestations of Nature and Politics in Mahmoud Darwish’s Metaphors

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    This paper is an analytical study investigating metaphors, the most aesthetic device, in the poetry of Mahmoud Darwish. In this study, the researcher categorized metaphors into three main groups: metaphors of plants and  trees like wheat, metaphors of birds and animals as the hoopoe, butterfly, and dove, and metaphors of abstract and concrete elements of nature. The researcher concluded that metaphors employed in the Darwishian poetry are linguistic and cultural phenomena. Darwish focuses on the use of metaphors connected with nature with the help of which he turns the sign into the signified, the subject into the object, and nothingness into something, thus transferring the land of Palestine into a poem and making this poem one with Palestine. More importantly, metaphor is a sort of manifestation of identity, a paradoxical and illogical one since it is ‘this’ and ‘that’ at the same time. It combines two entities together that are similar and dissimilar. The poet resorts to metaphor as to the most unrestrained method of thinking in order not to prove anything through reasoning, but rather to reveal a concealed and subtle truth which paradoxically affirms that “poem and land are one.” Keywords: metaphor, aesthetic device, metaphors of plants, metaphors of animals, metaphors of nature. DOI: 10.7176/JLLL/66-08 Publication date:March 31st 202
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