The J-OC-PSP (decomposition of J into Orbital Contributions using Orbital Currents and Partial Spin Polarization) method is applied to analyze NMR spin-spin coupling constants in polyenes, which were calculated using coupled perturbed density functional theory in connection with the B3LYP hybrid functional and a [7s,6p,2d/4s,2p] basis set. The analysis revealed that the pi-mechanism for Fermi c...

We study the stability of orientationally disordered crystal phases in a suspension of colloidal hard dumbbells using Monte Carlo simulations. For dumbbell bond length L/sigma<0.4 with L the separation of the two spheres of the dumbbell and sigma the diameter of the spheres, we determine the difference in Helmholtz free energy of a plastic crystal with a hexagonal-close-packed (hcp) and a face-...

In dynamic force spectroscopy, a (bio-)molecular complex is subjected to a steadily increasing force until the chemical bond breaks. Repeating the same experiment many times results in a broad distribution of rupture forces, whose quantitative interpretation represents a formidable theoretical challenge. In this study we address the situation that more than a single molecular bond is involved i...

An analytical theory is developed for the position of the resonances in near-edge X-ray absorption fine structure (NEXAFS) which yields extremely good agreement with experiment and allows a universal curve to be calculated for the resonance energies. The analytical calculations indicates that, if scattering events are taken as purely atomic, the product kp = constant, where k is the wavevector ...

OBJECTIVES This study evaluated the effect of three antioxidizing agents on pull-out bond strengths of dentin treated with sodium hypochlorite. MATERIALS AND METHODS Root canals of 75 single-rooted human teeth were prepared. Fifteen teeth were irrigated with normal saline for a negative control group, and the remaining 60 teeth (groups 2 - 5) with 2.5% NaOCl. The teeth in group 2 served as a ...

enterprise resource planning (erp) has become the most strategic tool for an organization to employ. a leading erp solution is sap®. it has been employed by organizations to enable them to collaborate on different projects and to integrate all aspects of operations. just as organizations have adopted erp solutions, they employed quality initiatives that are designed to help organizations maximi...

In this paper, by considering the notion of $Sigma$-hyperalgebras for an arbitrary signature $Sigma$, we study the notions of regular and strongly regular relations on a $Sigma$-hyperalgebra, $mathfrak{A}$. We show that each regular relation which contains a strongly regular relation is a strongly regular relation. Then we concentrate on the connection between the fundamental relation of $mathf...

The HOOO(-) anion (1) can adopt a triplet state (T-1) or a singlet state (S-1), where the former is 9.8 kcal/mol (DeltaH(298) = 10.3 kcal/mol) more stable than the latter. S-1 possesses a strong O-OOH bond with some double bond character and a weakly covalent OO-OH bond (1.80 A) according to CCSD(T)/6-311++G(3df,3pd) calculations (the longest O-O bond ever found for a peroxide). In aqueous solu...

We propose a critical spin liquid ground state for S=1/2 antiferromagnets on the square lattice. In a renormalization group analysis of the "staggered flux" algebraic spin liquid, we examine perturbations, present in the antiferromagnet, which break its global SU(4) symmetry to SO(5). At physical parameter values, we find an instability towards a fixed point with SO(5) symmetry. We discuss the ...