Existence results to a nonlinear p(k)-Laplacian difference equation

In the present paper, by using variational method, the existence of non-trivial solutions to an anisotropic discrete non-linear problem involving p(k)-Laplacian operator with Dirichlet boundary condition is investigated. The main technical tools applied here are the two local minimum theorems for differentiable functionals given by Bonanno.     

Existence and multiplicity of the solutions of the p(x)–Kirchhoff type equation via genus theory

In this paper, by using variational approach and Krasnoselskii's genus theory, we show the existence and multiplicity of the solutions of the p(x)‐Kirchhoff type equation. Copyright © 2011 John Wiley & Sons, Ltd.     

Synthesis,antioxidant activity and SAR study of novel spiro-isatin-based Schiff bases

Molecular Diversity - A new series of 21 Schiff bases of spiro-isatin was synthesized, and their DPPH, CUPRAC and ABTS cation radical scavenging abilities were investigated for antioxidant...     

Computer-simulated determination of isoconcentration lines for unsteady diffusion in a cylindrical body

The diffusion functions in the radial and axial directions of a cylindrical body are evaluated using an iterative method and a computer plotter system. For a given total concentration and relative radius, the relative height of this cylinder is calculated. Using the above parameters new diagrams for isoconcentration lines are plotted.

---

Die Bestimmung von Isokonzentrationslinien für instationäre Diffusion in einem zylindrischen Körper

Zusammenfassung Nach einer iterativen Methode und mit Hilfe eines Computers wird versucht, die Diffusionsfunktionen in den radialen und axialen Richtungen eines zylindrischen Körpers zu berechnen. Für eine vorgegebene Gesamtkonzentration und einen relativen Radius wird die relative Höhe des Zylinders ermittelt. Bei Anwendung der obigen Parameter werden neue Diagramme für Isokonzentrationslinen dargestellt.

     

Modeling the free radical polymerization of acrylates

Acrylates have gained importance because of their ease of conversion to high‐molecular‐weight polymers and their broad industrial use. Methyl methacrylate (MMA) is a well‐known monomer for free radical polymerization, but its α‐methyl substituent restricts the chemical modification of the monomer and therefore the properties of the resulting polymer. The presence of a heteroatom in the methyl group is known to increase the polymerizability of MMA. Methyl α‐hydroxymethylacrylate (MHMA), methyl α‐methoxymethylacrylate (MC₁MA), methyl α‐acetoxymethylacrylate (MAcMA) show even better conversions to high‐molecular‐weight polymers than MMA. In contrast, the polymerization rate is known to decrease as the methyl group is replaced by ethyl in ethyl α‐hydroxymethylacrylate (EHMA) and t‐butyl in t‐butyl α‐hydroxymethylacrylate (TBHMA). In this study, quantum mechanical tools (B3LYP/6‐31G*) have been used in order to understand the mechanistic behavior of the free radical polymerization reactions of acrylates. The polymerization rates of MMA, MHMA, MC₁MA, MAcMA, EHMA, TBHMA, MC₁AN (α‐methoxymethyl acrylonitrile), and MC₁AA (α‐methoxymethyl acrylic acid) have been evaluated and rationalized. Simple monomers such as allyl alcohol (AA) and allyl chloride (AC) have also been modeled for comparative purposes. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005     

Molecular structure, IR and NMR spectra of 2,6 distyrylpyridine by density functional theory and ab initio Hartree-Fock calculations

Vibrational frequencies and gauge including atomic orbital (GIAO) 13C NMR and 1H NMR chemical shift values of 2,6 distyrylpyridine (C21H17N) in the ground state have been calculated by using the Hartree-Fock (HF) and density functional method (B3LYP) with 6-31G(d) basis set. These methods are proposed as a tool to be applied in the structural characterization of 2,6 distyrylpyridine (C21H17N). The title compound has C2v point group, thus providing useful support in the interpretation of experimental IR data. In addition, obtained results were related to the linear correlation plot of experimental 13C NMR, 1H NMR chemical shifts values and IR data.     

Molecular structure, vibrational and chemical shift assignments of 8-hydroxy-1-methylquinolinium iodide hydrate by density functional theory (DFT) and ab initio Hartree-Fock (HF) calculations

The molecular geometry, the normal mode frequencies and corresponding vibrational assignments, (1)H and (13)C NMR chemical shift values of 8-hydroxy-1-methylquinolinium iodide monohydrate [(C(10)H(10)NO)(+)I(-)H(2)O] in the ground state were performed by HF and B3LYP levels of theory using the LanL2DZ basis set. The optimized bond lengths and bond angles are in good agreement with the X-ray data. The vibrational spectra of the title compound which is calculated by HF and DFT methods, reproduces vibrational wave numbers and intensities with an accuracy which allows reliable vibrational assignments. The title compound [(C(10)H(10)NO)(+)I(-)H(2)O] have been studied theoretically in the 4, 000-200 cm(-1) region and the assignment of all the observed bands were made. The analysis of the infrared spectra indicates that there are some structure-spectra correlations. These methods are proposed as a tool to be applied in the structural characterization of 8-hydroxy-1-methylquinolinium iodide monohydrate [(C(10)H(10)NO)(+)I(-)H(2)O], and thus providing useful support in the interpretation of experimental NMR data.     

Functionalization and crosslinking reactions of ethyl-α-hydroxymethylacrylate

Ethyl-α-hydroxymethylacrylate (EHMA) was esterified with hexanoyl chloride in 80% yield. The homopolymer of the hexanoate ester was found to be a glassy thermoplastic and soluble polymer. Copolymerization of the hexanoate ester with EHMA in varying ratios gave polymers that were thermoplastic and more soluble as a result of internal lubrication of the long alkyl pendant groups. Copolymers with styrene were synthesized with relatively high conversion. Reaction of EHMA with adipoyl chloride gave a bis-ester which served as crosslinking agent when copolymerized with different monomers including EHMA itself. In a separate synthesis EHMA was reacted with toluenediisocyanate (TDI). In the absence of catalyst a monourethane was formed. This monomer still contains one isocyanate function and is capable of further reactions subsequent to double bond addition polymerization. This reaction was also carried out on poly-EHMA, with or without catalyst. The products were the mono and the crosslinked bisurethanes as expected. Thus, acyl chlorides and isocyanates were found to be excellent reagents for derivatization of EHMA. © 1993 John Wiley & Sons, Inc.     

Synthesis and photopolymerizations of first monomers with phosphonate and bisphosphonate or phosphonic and bisphosphonic acid functionalities for potential dental applications

The first monomers containing both phosphonate and bisphosphonate (M1) or phosphonic and bisphosphonic acid (M2) functionalities are synthesized, aiming to improve binding abilities of self-etching adhesive systems and composites: An amine having both phosphonate and bisphosphonate functionalities is prepared via Michael addition reaction between diethyl (6-aminohexyl)phosphonate and tetraethyl vinylidene bisphosphonate, its reaction with 2-isocyanatoethyl methacrylate gives M1 which is converted to M2 by selective dealkylation of the phosphonate/bisphosphonate ester groups. Their copolymerization with commercial dental monomers (bisphenol A glycidyl methacrylate, triethylene glycol dimethacrylate, and 2-hydroxyethyl methacrylate) investigated by photo-differential scanning calorimetry shows adequate photopolymerization rate and conversion. X-ray diffraction, Fourier transform infrared, and X-ray photoelectron spectroscopy analyses of M2-treated hydroxyapatite particles show formation of stable M2-calcium salts. These monomers are assessed to be not toxic according to MTT standards by in vitro cytotoxicity studies with NIH 3T3, U2OS, and Saos-2 cells. All these properties make these monomers potential candidates as biocompatible components for dental adhesives and composites. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 , 56, 2739–2751