Synthesis, characterization, structure determination from powder X-ray diffraction data, and biological activity of azo dye of 3-aminopyridine and its complexes of Ni(II) and Cu(II)

In the present work azo dye ligand of 3-aminopyridine (L) and its complexes of NiII and CuII were synthesized, characterized and evaluated for antibacterial and antifungal activities in vitro. The L ligand was synthesized by reacting diazonium ion of 3-aminopyridine with 1-naphthole in presence of sodium acetate. The ligand (L) and its complexes were characterized by elemental analysis (CHN), magnetic susceptibility, molar conductivity, UV-Vis spectra, and infrared technique. The (L) azo dye exhibited high sensing for the pH changes. The color of L dye changed from red in basic medium to yellow color in acidic medium. The data of CHN, UV-Vis and magnetic susceptibility indicate that the complexes [Ni(L)2Cl2] and [Cu(L)2Cl2] are tetrahedral. The complexes of Ni(II) and Cu(II) exhibited potent activity against growth of Staphylococcus aureus and Escherichia Coli as well as against Penicillium Sp. And Aspergillus niger. Under visible irradiation (395 nm), the (L) azo dye of pyridine exhibited a significant change in the spectra under irradiation.                     KEY WORDS: Pyridine, Photoisomerization, Pyridylazo, Biological activity, pH sensor   Bull. Chem. Soc. Ethiop. 2020, 34(3), 523-532. DOI: https://dx.doi.org/10.4314/bcse.v34i3.

Towards a Realization of the Condensed-Matter/Gravity Correspondence in String Theory via Consistent Abelian Truncation

We present an embedding of the 3-dimensional relativistic Landau-Ginzburg model for condensed matter systems in an $\mathcal{N}=6$, $U(N)\times U(N)$ Chern-Simons-matter theory (the ABJM model) by consistently truncating the latter to an abelian effective field theory encoding the collective dynamics of ${\cal O}(N)$ of the ${\cal O}(N^2)$ modes. In fact, depending on the VEV on one of the ABJM scalars, a mass deformation parameter $\mu$ and the Chern-Simons level number $k$, our abelianization prescription allows us to interpolate between the abelian Higgs model with its usual multi-vortex solutions and a $\phi^4$ theory. We sketch a simple condensed matter model that reproduces all the salient features of the abelianization. In this context, the abelianization can be interpreted as giving a dimensional reduction from four dimensions.Comment: 4 pages, revtex; reference added, typo corrected; added clarifying paragraphs at end of introduction and on pages 3-4. Version accepted to PR

Numerical solution for the time-Fractional Diffusion-wave Equations by using Sinc-Legendre Collocation Method

In this paper the numerical solution of fractional diffusion wave equation is proposed. The fractional derivative will be in the Caputo sense. The proposed method will be based on shifted Legendre collocation scheme and sinc function approximation for time and space respectively. The problem is reduced to the problem into a system of algebraic equations after implementing this method. For demonstrating the validity and applicability of the proposed numerical scheme some examples are presented. Keywords: Fractional diffusion equation, Sinc functions, shifted Legendre  polynomials, Collocation method

Spectroscopy Characterization of Ethylene Vinyl Acetate Degradation by Different Kinds of Accelerated Aging

يقدم البحث رؤية حول التشوه الحاصل في التركيب الكيمياوي للبوليمر المشترك المتحلل  اثلين فنيل الخلات EVA وذلك بحسب تغير نسبة قيم ثوابت المعدل المستحصلة من منحنيات الحركية الطيفية للعينات المتحللة. اذ تم تحديد  تضبيط رسم منحنيات الحركية الطيفية للفلورة ولمجالين مميزين من الاطوال الموجية لشدات الفلورة. حيث أظهرت الاطوال الموجية القصيرة (320-400 nm) تداخلا في الاطياف, بينما عند الاطوال الموجية الطويلة (400-800 nm) بدت الاطياف منتظمة وحسب أزمنة التعتيق المعجل. أن النسبة لثابت معدل سرعة التفاعل  عند الاطوال الموجية الطويلة الى ثابت معدل سرعة التفاعل للاطوال الموجية القصيرة هو المعيار لدرجة التشوه في البنية الكيمياوية. حيث يعتمد المعامل المولاري الخارجي على البنية الكيمياوية. من خلال قياس الامتصاصية, تم تصنيف نماذج EVA الى مجموعتين. اذ ان وجود اضافات Cyasorb هي النقطة الرئيسية في التصنيف. تم دراسة تأثير الأنواع المختلفة للتعتيق المعجل وهي, تسخين جاف عند 115 ℃و تسخين رطب عند رطوبة نسبية مقدارها 85% ودرجة حرارة 85 ℃ وتعتيق التشعيع بالاشعة فوق البنفسجية عند درجة حرارة 65 ℃ وعند ازمنة تعتيق مختلفة لكل مجموعة. وقد تم مناقشة نتائج اطياف الامتصاص والفلورة للعينات. اجمالا, فان اضافة Cyasorb تسبب تشوه اعلى في التركيب الكيمياوي عند تحلل. EVA  أن العامل الاكثر تأثيرا هو التعتيق الرطب بينما الاقل يحصل بواسطة التشعيع بالاشعة فوق البنفسجية. بينما تغير التركيب الكيمياوي الاكبر يحدث للعينة الخالية من اضافة Cyasorb , حيث ينتج من التعتيق الرطب أما التغير الاقل فينتج بواسطة التسخين الجاف.            This paper presents a sight about the chemical structure deformation of poly (ethylene-co-vinyl acetate) (EVA) samples according to the change ratio of rate constant values. Spectroscopy kinetics fluorescence curves are fitted for two characteristic wavelength domains of fluorescent intensities. The short wavelengths (320-400 nm) domain show spectra overlapping, while at long wavelengths (400-800 nm) domain spectra are arranged in regular for each specific accelerated aging time. The ratio of kinetics rate constant at long wavelengths to kinetics rate constant of short wavelengths is the criterion of the degree chemical structure deformation. Molar extrinsic coefficient relies on the chemical structure change. Through absorbance measurement, EVA samples have been classified into two groups. Presence of Cyasorb additive is the key point of the ranking. The effect of three different accelerated aging of dry (115 oC), damp (85% moisture, 85 oC), and irradiated (UV, 65 oC) aging have been considered for two samples of each group over different aging time. Spectroscopy of absorbance and fluorescent for aged samples have been discussed. In general, Cyasorb adding causes higher chemical structure deformation for the EVA sample. The most effective factor is the damp aging and the less one is the UV irradiation aging, while the biggest chemical structure change of Cyasorb-free sample is produced by damp aging and the less by dry heat.  &nbsp