Search results for "Configuration"
showing 10 items of 601 documents
Fast vibrational configuration interaction using generalized curvilinear coordinates and self-consistent basis
2010
In this paper, we couple a numerical kinetic-energy operator approach to the direct-vibrational self-consistent field (VSCF)/vibrational configuration interaction (VCI) method for the calculation of vibrational anharmonic frequencies. By combining this with fast-VSCF, an efficient direct evaluation of the ab initio potential-energy surface (PES), we introduce a general formalism for the computation of vibrational bound states of molecular systems exhibiting large-amplitude motion such as methyl-group torsion. We validate our approach on an analytical two-dimensional model and apply it to the methanol molecule. We show that curvilinear coordinates lead to a significant improvement in the VSC…
Synthesizing on a reconfigurable chip an autonomous robot image processing system
2003
This paper deals with the implementation, in a high density reconfigurable device, of an entire log-polar image processing system. The log-polar vision reduces the amount of data to be stored and processed, simplifying several vision algorithms and making it possible the implementation of a complete processing system on a single chip. This image processing system is specially appropriated for autonomous robotic navigation, since these platforms have typically power consumption, size and weight restrictions. Furthermore, the image processing algorithms involved are time consuming and many times they have also real-time restrictions. A reconfigurable approach on a single chip combines hardwar…
The electronic spectra of 2-(2′-hydroxybenzoyl)pyrrole and 2-(2′-methoxybenzoyl)pyrrole: a theoretical study
2005
The gas-phase electronic spectra of 2-(2 0 -hydroxybenzoyl)pyrrole and 2-(2 0 -methoxybenzoyl)pyrrole have been determined using multiconfigurational perturbation theory (CASPT2). Solvatochromic spectral shifts for these molecules have been measured in cyclohexane and methanol and the electrostatic components of these shifts have been estimated using the vertical electrostatic model (VEM 4.2) developed for the configuration interaction with single excitations model implemented with the intermediate neglect of differential overlap Hamiltonian (CIS/INDO/ S2). Comparison between theory and experiment and an interpretation of the main spectral differences between the two substituted pyrroles an…
Thermische Diels-Alder-Reaktionen mitN-(2-Alkenoyl)-(S)-prolinestern als chiralen Dienophilen in organischen und wäßrigen Reaktionsmedien
1990
Thermal Diels-Alder Reactions with N-(2-Alkenoyl)-(S)-proline Esters as Chiral Dienophiles Cyclopentadiene reacts with N-acryloyl-(S)-proline benzyl and allyl ester in toluene at 0°C to give the bicycloheptene-carboxylic acid amides with a stereoselection of (2S):(2R) = 81:19. In the reactions with the N,N′-fumaroylbis(proline esters) the cycloadducts are formed in high yields and with isomer ratios of up to 97:3. The absolute configuration of N,N′-〈(1R,2R,3R,4S)-bicyclo[2.2.1]hept-5-ene-2,3-diyldicarbonyl〉bis-[(S)-proline benzyl ester] (6 a) has been determined by an X-ray analysis. In the reactions of the acrylamides with cyclopentadiene and of the fumaramides with cyclopentadiene, isopre…
Novel σ1 antagonists designed for tumor therapy: Structure – activity relationships of aminoethyl substituted cyclohexanes
2021
Abstract Depending on the substitution pattern and stereochemistry, 1,3-dioxanes 1 with an aminoethyl moiety in 4-position represent potent σ1 receptor antagonists. In order to increase the stability, a cyclohexane ring first replaced the acetalic 1, 3-dioxane ring of 1. A large set of aminoethyl substituted cyclohexane derivatives was prepared in a six-step synthesis. All enantiomers and diastereomers were separated by chiral HPLC at the stage of the primary alcohol 7, and their absolute configuration was determined by CD spectroscopy. Neither the relative nor the absolute configuration had a large impact on the σ1 affinity. The highest σ1 affinity was found for cis-configured benzylamines…
Evaluation of different InSAR multi-baseline construction methods over a dam in southern Italy
2018
Monitoring dam displacements using different techniques allows an evaluation of their structural behaviour over time. In this study, dam displacements (for the Castello dam, Agrigento, Italy) have been investigated using different Interferometric Synthetic Aperture Radar (InSAR) techniques exploiting a freely available dataset from the EU Copernicus Sentinel-1 SAR built by the European Space Agency (ESA). The dataset includes Sentinel 1A (S1A) images acquired in dual-polarization and Interferometric Wide (IW) swath using the Terrain Observation with Progressive Scans SAR (TOPSAR) mode. Three main Multi-Baseline Construction methods based on the identification of Persistent Scatterers (PS) h…
Das Unheimliche (Postcolonialisme et reconfiguration à l'extrême gauche). Autour d'une configuration, à partir de : Race et Capitalisme, Les Cahiers …
2013
International audience; Pourquoi ce titre, emprunté à Sigmund Freud1, pourquoi à propos d'une livraison pour Syllepse d'un numéro des Cahiers de l'émancipation ? Le propos n'est pas une lecture pathologique, mais davantage symptomale, soit une façon – à la manière assumée d'un usage « sauvage » du lexique psychanalytique tel que pratiquée naguère par l'histoire du temps présent – de questionner une part de l'agency 2 de l'extrême gauche française contemporaine, entre stratégie(s) académique(s), reconfiguration(s) politique(s) autour des questions du postcolonialisme, du marxisme et de son efficace politique sur la scène française. Cette livraison offre un dossier « Race et capitalisme » coo…
The HisClima database: historical weather logs for automatic transcription and information extraction
2021
Knowing the weather and atmospheric conditions from the past can help weather researchers to generate models like the ones used to predict how weather conditions are likely to change as global temperatures continue to rise. Many historical weather records are available from the past registered on a systemic basis. Historical weather logs were registered in ships, when they were on the high seas, recording daily weather conditions such as: wind speed, temperature, coordinates, etc. These historical documents represent an important source of knowledge with valuable information to extract climatic information of several centuries ago. This paper presents a database for researching about the ca…
Enhanced β-turn conformational stability of tripeptides containing Δphe in cis over trans configuration
2013
Conformations of three pairs of dehydropeptides with the opposite configuration of the Delta Phe residue, Boc-Gly-Delta(Z/E)Phe-Phe-p-NA (Z- p -NA and E- p -NA), Boc-Gly-Delta(Z/E)Phe-Phe-OMe (Z-OMe and E-OMe), and Boc-Gly-Delta(Z/E)Phe-Phe-OH (Z-OH and E-OH) were compared on the basis of CD and NMR studies in MeOH, TFE, and DMSO. The CD results were used as the additional input data for the NMR-based calculations of the detailed solution conformations of the peptides. It was found that Z- p -NA, E- p -NA, Z-OMe, and Z-OH adopt the beta-turn conformations and E-OMe and E-OH are unordered. There are two overlapping type III beta-turns in Z- p -NA, type II' beta-turn in E- p -NA, and type II …
Ultra-fast intensified frame images from an electron cyclotron resonance hydrogen plasma at 2.45 GHz: some space distributions of visible and monochr…
2014
First results from an ultra-fast frame image acquisition diagnostic coupled to a 2.45 GHz microwave hydrogen discharge are presented. The plasma reactor has been modified to include a transparent doubled shielded quartz window allowing to viewing the full plasma volume. Pictures describing the breakdown process at 1μs exposure time have been obtained for integrated visible light signal, Balmer-alpha, Balmer-beta lines, and Fulcher-band. Several different plasma emission distributions are reported. The distribution depends on the magnetic field configuration, incident microwave power, and neutral gas pressure. peerReviewed