N.M.R. study of segmental molecular interactions in liquid crystals

Abstract

A simple statistical model of interacting non-rigid molecules, based on a perturbation expansion of the pair correlation function and the additivity of segmental interactions, is applied to the study of orientational order as measured by N.M.R. in the nematic and S_A phases of 4-n-alkyl-4′-cyanobiphenyls (N-CB, N = 5 to 8), the nematic and S_C phases of 4-n-alkyloxybenzoic acids (N-OBA, N = 7, 8) and the D _h0 columnar discotic phase of hexa-alkyloxytriphenylenes (N-THE, N = 5 to 8). The order parameters of each homologous series are correctly described in terms of two isotropic and two anisotropic segmental coupling constants. The model predicts certain relations among coupling constants pertaining to different homogous series. These predictions are supported by the results obtained for the three types of compounds studied.     

Economic model predictive inventory routing and control

Central European Journal of Operations Research - The paper proposes an economic model predictive control (EMPC) strategy for the inventory routing problem under demand uncertainty. The strategy is...     

N.M.R. study of segmental molecular interactions in liquid crystals

A simple statistical model of interacting non-rigid molecules, based on a perturbation expansion of the pair correlation function and the additivity of segmental interactions, is applied to the study of orientational order as measured by N.M.R. in the nematic and S_A phases of 4-n-alkyl-4'-cyanobiphenyls (N-CB, N = 5 to 8), the nematic and S_C phases of 4-n-alkyloxybenzoic acids (N-OBA, N = 7, 8) and the D_h0 columnar discotic phase of hexa-alkyloxytriphenylenes (N-THE, N = 5 to 8). The order parameters of each homologous series are correctly described in terms of two isotropic and two anisotropic segmental coupling constants. The model predicts certain relations among coupling constants pertaining to different homogous series. These predictions are supported by the results obtained for the three types of compounds studied.     

Targeted therapies for advanced non-small cell lung cancer

The incorporation of targeted agents has considerably improved the management of patients with advanced non-small cell lung cancer (NSCLC) over the last years. The main targets include the epidermal growth factor receptor (EGFR) and the vascular endothelial growth factor (VEGF). Currently available agents with established role in NSCLC include the anti-EGFR tyrosine-kinase inhibitors (TKIs) erlotinib/gefitinib and the anti-VEGF monoclonal antibody bevacizumab. Moreover, several other agents targeting critical pathways in lung carcinogenesis are currently under preclinical or clinical evaluation. This review presents an update on the role of targeted agents in advanced NSCLC. In addition, we present the main clinical studies investigating the activity of these agents in NSCLC and we provide recent data with respect to future therapeutic strategies.     

A threshold accepting heuristic with intense local search for the solution of special instances of the traveling salesman problem

In real life scheduling, variations of the standard traveling salesman problem are very often encountered. The aim of this work is to present a new heuristic method for solving three such special instances with a common approach. The proposed algorithm uses a variant of the threshold accepting method, enhanced with intense local search, while the candidate solutions are produced through an insertion heuristic scheme. The main characteristic of the algorithm is that it does not require modifications and parameter tuning in order to cope with the three different problems. Computational results on a variety of real life and artificial problems are presented at the end of this work and prove the efficiency and the ascendancy of the proposed method over other algorithms found in the literature.     

Elastohydrodynamic analysis and Pareto optimization of intact,worn and misaligned journal bearings

In this paper, we propose an engineering approach for the elastohydrodynamic (EHD) analysis and optimization of the steady operation of intact, worn or/and misaligned journal bearings. We develop an iterative algorithm, based on finite element formulations for both the hydrodynamic lubrication and the elastic deformation of the bearing pad, which converges to the solution of the coupled problem. In addition, we formulate a multi-objective optimization problem, and seek combinations of the design variables, namely, length-to-diameter ratio, Sommerfeld number and bearing deformation coefficient, which minimize simultaneously the normalized friction coefficient and the normalized maximum pressure, under intact and representative fault conditions. Optimal solutions are identified based on the Pareto dominance, and are physically interpreted. The present development provides a tool for optimally reducing the parameter space of independent variables in EHD journal bearing design.