Search results for "AH"

ChemInform Abstract: Synthesis and Magnetic Properties of Bis(μ-hydroxo)bis((2,2′-bipyridyl)copper(II)) Squarate. Crystal Structure of Bis(μ-hydroxo)…

1990

Abstract The compound [Cu2(bipy)2(OH)2](C4O4)·5.5H2O, where bipy and C4O42− correspond to 2,2′-bipyridyl and squarate (dianion of 3,4-dihydroxy-3-cyclo- butene-1,3-dione) respectively, has been synthesized. Its magnetic properties have been investigated in the 2–300 K temperature range. The ground state is a spin-triplet state, with a singlet-triplet separation of 145 cm−1. The EPR powder spectrum confirms the nature of the ground state. Well-formed single crystals of the tetrahydrate, [Cu2(bipy)2(OH)2](C4O4)·4H2O, were grown from aqueous solutions and characterized by X-ray diffraction. The system is triclinic, space group P 1 , with a = 9.022(2), b = 9.040(2), c = 8.409(2) A, α = 103.51(2…

New Heuristic Algorithms for the Windy Rural Postman Problem

2005

[EN] In this paper we deal with the windy rural postman problem. This problem generalizes several important arc routing problems and has interesting real-life applications. Here, we present several heuristics whose study has lead to the design of a scatter search algorithm for the windy rural postman problem. Extensive computational experiments over different sets of instances, with sizes up to 988 nodes and 3952 edges, are also presented. (c) 2004 Elsevier Ltd. All rights reserved.

Kolonizacja ziem palestyńskich jako czynnik korupcjogenny w Izraelu

2017

Celem tekstu jest wielowymiarowe nakreślenie problematyki korupcji w Izraelu w kontekście projektu kolonizacji ziem palestyńskich. Artykuł składa się z czterech części. Pierwsza pokrótce omawia – opierając się na badaniach opinii społecznej – skalę postrzeganej przez izraelskie społeczeństwo korupcji. Druga analizuje pogranicze między Izraelem a Palestyńczykami. Trzecia kontynuuje wcześniejsze rozważania, skupiając się na wywłaszczeniach Palestyńczyków, dokonywanych przez państwo izraelskie. Ostatnia zawiera przykłady korupcji wśród najwyższych oficjeli izraelskich. W podsumowaniu zwraca się uwagę na potrzebę nowych badań, rozwijających niniejszą analizę.

Mononuclear and tetranuclear Fe(III) complexes with two different types of N, O donor Schiff base ligands

2013

Abstract A mononuclear Fe(III) complex of a tetradentate N 2 O 2 donor Schiff base ligand derived from 3-ethoxysalicaldehyde and ethylenediamine has been reported. In addition two tetranuclear Fe(III) complexes with discrete Fe 4 III (μ 4 -O) cores have been synthesized and characterized using two Schiff base ligands (H 2 L 1–2 ) derived from two different aromatic acid hydrazides and diacetyl monoxime. The mononuclear Fe(III) and one of the tetranuclear Fe(III) complexes have been structurally characterized by single-crystal X-ray crystallography. The mononuclear complex has a highly distorted octahedral geometry. The tetranuclear Fe(III) complexes are found to be rare examples with discre…

1981

The anionic polymerization of tert-butyl methacrylate (TBMA) in tetrahydrofuran, using Na+ and Cs+ as counterions proceeds without side reactions even at room temperature. The resulting molecular weight distributions are nearly monodisperse (Mw/Mn ⩽ 1,01). The rate constants for the propagation of ion pairs were measured in the range from + 15 to −100°C. The Arrhenius plots are linear, but different for the two counterions, resulting in the following numerical values for the frequency exponent A and the activation energy Ea: A = 8,5 and Ea = 7,2 kcal/mol = 30 kJ/mol for Na+; A = 9,5 and Ea = 5,6 kcal/mol = 23 kJ/mol for Cs+. The difference between the counterions, which is in contrast to th…

Über die frühen Werke von Carl Gotthard Graß in der Akademischen Bibliothek der Universität Lettlands, über die Freundschaft, Antiquarismus in der Ge…

2020

Evolutionary Algorithms and Metaheuristics : Applications in Engineering Design and Optimization

2018

Development of artificial neural network for condition assessment of bridges based on hybrid decision making method – Feasibility study

2021

Abstract Managing a bridge at an appropriate level of reliability requires knowledge of its technical condition, which is decisive in terms of maintenance and repair activities. This is a multi-criteria decision-making problem which results from the need to allocate limited financial resources to this work. Although many calculation models have been suggested in published sources, none of them has ever met these requirements. The algorithm presented by the authors allows for the assessment of any number of bridges, taking into account the diversity of solutions in terms of materials and structures, and can provide a solution to this problem. This hybrid calculation model, combining the modi…

Tabu and Scatter Search for Artificial Neural Networks

2003

In this paper we address the problem of training multilayer feed-forward neural networks. These networks have been widely used for both prediction and classification in many different areas. Although the most popular method for training these networks is back propagation, other optimization methods such as tabu search or scatter search have been applied to solve this problem. This paper presents a new training algorithm based on the tabu search methodology that incorporates elements for search intensification and diversification by utilizing strategic designs where other previous approaches resort to randomization. Our method considers context and search information, as it is provided by th…

Hybrid prediction-optimization approaches for maximizing parts density in SLM of Ti6Al4V titanium alloy

2022

AbstractIt is well known that the processing parameters of selective laser melting (SLM) highly influence mechanical and physical properties of the manufactured parts. Also, the energy density is insufficient to detect the process window for producing full dense components. In fact, parts produced with the same energy density but different combinations of parameters may present different properties even under the microstructural viewpoint. In this context, the need to assess the influence of the process parameters and to select the best parameters set able to optimize the final properties of SLM parts has been capturing the attention of both academics and practitioners. In this paper differ…