A modulus gradient model for an axially loaded inhomogeneous elastic rod

A new gradient elasticity formulation is proposed for a one-dimensional linear elastic inhomogeneous rod. In the new formulation, similar to the differential relation between the local strain and the gradient enhanced strain in the classical models of gradient elasticity, a differential relation is proposed for the Young’s modulus. Analytical and finite element solutions of the proposed formulation are derived. Results of the proposed model are compared with a classical model of gradient elasticity for a model problem of carbon nanotube reinforced polymer composite.     

An efficient synthesis of a rationally designed 1,5 disubstituted imidazole AT<Subscript>1</Subscript> Angiotensin II receptor antagonist: reorientation of imidazole pharmacophore groups in losartan reserves high receptor affinity and confirms docking studies

A new 1,5 disubstituted imidazole AT₁ Angiotensin II (AII) receptor antagonist related to losartan with reversion of butyl and hydroxymethyl groups at the 2-, 5-positions of the imidazole ring was synthesized and evaluated for its antagonist activity (V8). In vitro results indicated that the reorientation of butyl and hydroxymethyl groups on the imidazole template of losartan retained high binding affinity to the AT₁ receptor concluding that the spacing of the substituents at the 2,5- positions is of primary importance. The docking studies are confirmed by binding assay results which clearly show a comparable binding score of the designed compound V8 with that of the prototype losartan. An efficient, regioselective and cost effective synthesis renders the new compound as an attractive candidate for advanced toxicological evaluation and a drug against hypertension.     

Nanostructure‐Directed Physisorption vs Chemisorption at Semiconductor Interfaces: The Inverse of the HSAB Concept

A concept, complementary to that of hard and soft acid–base interactions (HSAB‐dominant chemisorption) and consistent with dominant physisorption to a semiconductor interface, is presented. We create a matrix of sensitivities and interactions with several basic gases. The concept, based on the reversible interaction of hard‐acid surfaces with soft bases, hard‐base surfaces with soft acids, or vice versa, corresponds 1) to the inverse of the HSAB concept and 2) to the selection of a combination of semiconductor interface and analyte materials, which can be used to direct a physisorbed vs chemisorbed interaction. The technology, implemented on nanopore coated porous silicon micropores, results in the coupling of acid–base chemistry with the depletion or enhancement of majority carriers in an extrinsic semiconductor. Using the inverse‐HSAB (IHSAB) concept, significant and predictable changes in interface sensitivity for a variety of gases can be implemented. Nanostructured metal oxide particle depositions provide selectivity and complement a highly efficient electrical contact to a porous silicon nanopore covered microporous interface. The application of small quantities (much less than a monolayer) of nanostructured metals, metal oxides, and catalysts which focus the physisorbtive and chemisorbtive interactions of the interface, can be made to create a range of notably higher sensitivities for reversible physisorption. This is exemplified by an approach to reversible, sensitive, and selective interface responses. Nanostructured metal oxides developed from electroless gold (Au_xO), tin (SnO₂), copper (Cu_xO), and nickel (NiO) depositions, nanoalumina, and nanotitania are used to demonstrate the IHSAB concept and provide for the detection of gases, including NH₃, PH₃, CO, NO, and H₂S, in an array‐based format to the sub‐ppm level.     

Gamow-Teller 1<Superscript>+</Superscript> states in <Superscript>112–124</Superscript>Sb isotopes

The violated supersymmetry property of the pairing interaction between nucleons were restored using the Pyatov method [Pyatov and Salamov, Nucleonica 22, 127 (1977)]. The eigenvalues and eigenfunctions of the restored Hamiltonian with the separable residual Gamow-Teller effective interactions in the particle-hole and particle-particle channels were solved within the framework of proton-neutron quasirandom phase approximation (pnQRPA). The Gamow-Teller resonance energies for ^112–124Sb isotopes and the differential cross-sections for Sn(³He, t)Sb reactions at E(³He) = 200 MeV occurring by the excitation of the Gamow-Teller resonance state were calculated. The calculated values were compared with other calculations and the corresponding experimental data.     

Spectroelectrochemistry of poly(ethylenedithiathiophene)--the sulfur analogue of poly(ethylenedioxythiophene)

Poly(3,4-ethylenedithiathiophene) (PEDTT) is a polythiophene-like conjugated polymer in which each thiophene ring is functionalized with an ethylenedithia bridge. As such, PEDTT is the sulfur analogue of the well-known poly(3,4-ethylenedioxythiophene) (PEDOT). Substituent effects, namely the presence of sulfur atoms in PEDTT replacing the oxygen atoms of PEDOT, do not provide a simple explanation for the different electronic properties of the two polymers in the neutral state. This paper reports the spectroscopic properties of PEDTT, studied by in situ techniques such as IR-, Vis-, and electron spin resonance (ESR) spectroelectrochemistry. The differences observed upon electrochemical oxidation of PEDTT and PEDOT (e.g., the different infrared active vibrational band patterns in IR spectroelectrochemistry as well as the different nature of the charged states) are even more marked than those observed in the neutral state. These results, with AM1 calculations, indicate conformational effects as a possible explanation for the different electronic and spectroscopic properties of PEDTT and PEDOT.     

Polynomial Basis Multiplication over GF(2 m )

In this paper, we describe, analyze and compare various multipliers. Particularly, we investigate the standard modular multiplication, the Montgomery multiplication, and the matrix–vector multiplication techniques.     

Determination of Naphthazarin Derivatives in 16 Alkanna Species by RP-LC Using UV and MS for Detection

As part of our ongoing studies, a new and validated method for analysis of isohexenyl-naphthazarines in Turkish Alkanna species was developed. By using reversed phase material (Synergi MAX RP) it was possible to determine four known isohexenylnaphthazarin-derivatives, namely alkannin, acetylalkannin, deoxyalkannin, and β,β-dimethylacrylalkannin within 25 min in n-hexane extracts of the roots. The quantification of these compounds in 16 Anatolian Alkanna species is described for the first time. In order to assure peak identity LC-MS experiments were performed. Quantitative results revealed that the most dominant compound in the extracts was β,β-dimethylacrylalkannin.     

Equivalence of Constrained Models

We study two constrained scalar models. Whilethere seems to be equivalence when the partiallyintegrated Feynman path integral is expandedgraphically, the dynamical behaviors of the two modelsare different when quantization is done using Diracconstraint analysis.     

Influence of the solvent on the crystal structure of PCBM and the efficiency of MDMO-PPV:PCBM ''plastic'' solar cells

Two crystal structures of PCBM, obtained from different crystallisation solvents, are presented; a proposed link with solvent dependence of the efficiency of MDMO-PPV:PCBM solar cells is described.     

Copper(II)–nickel(II) complexes of novel 1,9-dioxa-3,6-dithiacyclotridecane-10,12-dione and 1,4-dioxa-7,10-dithiacyclododecane-2,3-dione ligands

1,9-Dioxa-3,6-dithiacyclotridecane-10,12-dione (L¹), and 1,4-dioxa-7,10-dithiacyclododecane-2,3-dione, (L²), two novel ligands, and their mono- and di-nuclear copper(II) and/or nickel(II) complexes have been prepared and characterized by elemental analyses, ¹H- and ¹³C-n.m.r., i.r., magnetic moments and mass spectral studies. Elemental analyses, stochiometric and spectroscopic data on the complexes indicate that the metal ions are coordinated to the nitrogen, oxygen and sulphur atoms and the data support the proposed structure for the diones and their mono–dinuclear copper(II) complexes. Moreover, copper(II) complexes of the dione ligands have a 1:1 metal:ligand ratio.