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Partager le résultat de cette recherchePigments : myth, shape and structure / J. R. Fryer in SURFACE COATINGS INTERNATIONAL, Vol. 80, N° 9 (09/1997)
Titre : Pigments : myth, shape and structure Type de document : texte imprimé Auteurs : J. R. Fryer, Auteur Année de publication : 1997 Article en page(s) : P. 421-426 Note générale : Bibliogr. Langues : Anglais (eng) Tags : 'Article synthèse' 'Pigment organique' 'Interaction intermoléculaire' 'Structure cristalline' 'Mode empilement' Morphologie 'Forme 'Composé polaire' 'Relation fabrication structure' non Index. décimale : 667.9 Revêtements et enduits Résumé : The usual textbook describes pigments in terms of the chromophore, and may give a synthetic route by which this compound can be obtained as shown for an azo pigment below.
However, in practice as is well known to those in the industry - the organic synthesis is only part of the process of making a pigment, and indeed may only be a minor part. The handling - eg rheology, the dispersibility, solubility, the colour strength, and even the shade of the pigment are function of the crystal properties.
A molecule has colour by havinf fonctional groups whose electronic transitions absorb energy in the visible spectrum. These transitions can be affected by meighbouring groups within the molecule - particulary in conjugated systems - but also by neighbouring groups in adjacent molecules which are forced into close proximity by the crystal packing. An important aspect of any molecule, which is to be considered as a pigment, is the bonding within the crystal, and how this can affect molecular proximity, and the ultimate shape of the crystal which is formed. It is necessary to consider both molecular shape, and any polar functional groups which may dominate the packing of molecules in the crystal.Note de contenu : - TYPES OF STRUCTURE
- ORGANIC CRYSTALS
- NON-POLAR MOLECULES : Attractive.Dispersion forces - Repulsive forces
- POLAR MOLECULES : Packing of organic molecules in a crystal - Packing coefficient K
- CRYSTAL SHAPE
- CRYSTAL STRUCTUREPermalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=17219
in SURFACE COATINGS INTERNATIONAL > Vol. 80, N° 9 (09/1997) . - P. 421-426[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 006586 - Périodique Bibliothèque principale Documentaires Disponible 
Titre : Films formed from polystyrene latex/clay composites : A fluorescence study Type de document : texte imprimé Auteurs : Saziye Ugur, Auteur ; Önder Pekcan, Auteur ; Ayse Alemdar, Auteur Année de publication : 2005 Article en page(s) : p. 565-575 Note générale : Bibliogr. Langues : Américain (ame) Tags : 'Propriété optique' 'Spectrométrie de fluorescence' 'Etude Morphologique' Transparence Recuit 'Relation mise en oeuvre structure' 'Effet concentration' la température' propriété' Montmorillonite 'Formation film' 'Matériau renforcé' Dispersion composite' Argile Latex Polystyrène Index. décimale : 667.9 Revêtements et enduits Résumé : This study reports a steady-state fluorescence (SSF) technique for studying film formation from surfactant-free polystyrene (PS) latex and Na-montmorillonite (SNaM) composites. The composite films were prepared from pyrene (P)-labeled PS particles and SNaM clay at room temperature and annealed at elevated temperatures in 10-min intervals above glass transition temperature (Tq) of polystyrene. During the annealing processes, the transparency of the film improved considerably. Scattered light (IS) and fluorescence intensity (IP) from P were measured after each annealing step to monitor the stages of film formation. Evolution of transparency of composite films was monitored by using photon transmission intensity, Itr. Scanning electron microscopy (SEM) was used to detect the variation in physical structure of annealed composite films. Minimum film formation temperature, T0' and healing temperatures, Th' were determined. Void closure and interdiffusion stages were modeled and related activation energies were determined. It was observed that both activation energies increased as the percent of SNaM was increased in composite films. DOI : 10.1007/s11998-005-0016-8 En ligne : https://link.springer.com/content/pdf/10.1007%2Fs11998-005-0016-8.pdf Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=3804
in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH > Vol. 2, N° 7 (07/2005) . - p. 565-575[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 002327 - Périodique Bibliothèque principale Documentaires Disponible
Titre : Composite bridges : health monitoring and an evaluation of a temporary field repair system Type de document : texte imprimé Auteurs : Galib Abumeri, Auteur ; Rose Ragalini, Auteur Année de publication : 2006 Article en page(s) : p. 35-37 Note générale : Bibliogr. Langues : Anglais (eng) Tags : 'Etude théorique' 'Simulation numérique' 'Méthode élément fini' 'Mécanique rupture' Modélisation 'Intégrité structure' Endommagement Pont Application Réparation Monitorage 'Matériau composite' Index. décimale : 668.4 Plastiques, vinyles Résumé : Composite bridges offer many advantages compared to current steel and aluminium bridges, including lightweight and superior corrosion resistance. However, their use is challenged by damages due to punctures, impact loads, and deployment-related handling, dropping, and dragging. To address these challenges, a comprehensive research programme was undertaken to develop innovative field repair techniques. Note de contenu : - Methodology
- DPS background
- Evaluation of temporary field repairPermalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=13920
in JEC COMPOSITES MAGAZINE > N° 28 (11/2006) . - p. 35-37[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 005711 - Périodique Bibliothèque principale Documentaires Disponible
Titre : Composite payloag fairing structural architecture assessment and selection Type de document : texte imprimé Auteurs : Thomas M. Krivanek, Auteur ; Bryan C. Yount, Auteur Année de publication : 2012 Article en page(s) : p. 40-48 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Composites à fibres
Industries aérospatiales -- MatériauxTags : 'Matériaux composites' 'Structures 'Composites fibres' 'Poids lourds' 'Lancement levage' Charges Risques spatiale' 'Conception structure' Garde Index. décimale : 620.11 Matériaux (propriétés, résistance) Résumé : This paper provides a summary of the structural architecture assessments conducted and a recommendation for an affordable high performance composite structural concept to use on the
next generation heavy-lift launch vehicle, the Space Launch System (SLS).
The Structural Concepts Element of the Advanced Composites Technology (ACT) project and its follow on the Lightweight Spacecraft Structures and Materials (LSSM) project was tasked with evaluating a number of composite construction technologies for specific Ares V components : the Payload Shroud, the Interstage, and the Core Stage Intertank. Team studies strived to address the structural challenges, risks and needs for each of these vehicle components. Leveraging off of this work, the subsequent Composites for Exploration (CoEx) effort is focused on providing a composite structural concept to support the Payload Fairing for SLS.
This paper documents the evaluation and down selection of composite construction technologies and evolution to the SLS Payload Fairing. Development of the evaluation criteria (also referred to as Figures of Merit or FOMs), their relative importance, and association to vehicle requirements are presented. A summary of the evaluation results, and a recommendation of the composite concept to baseline in the Composites for Exploration (CoEx) project is presented.
The recommendation for the SLS Fairing is a Honeycomb Sandwich architecture based primarily on affordability and performance with two promising alternatives, Hat stiffened and Fiber Reinforced Foam (FRF) identified for eventual program block upgrade.Note de contenu : - PAYLOAD FAIRING REQUIREMENTS AND CONFIGURATION
- EVALUATION CRITERIA AND PRIORITY : Basic mass - Damage tolerance during use - Sensitivity to fabrication defects - Joint mass - Non-recurring cost + 20 production units - Acoustic transmissibility - Repairability - Thermal tolerance - Flexibility in desing - Non-destructive evaluation and inspectability - Environmental sensitivity - Structural health monitoring - Trade process
- RISK AND UNCERTAINTY ISSUES
- RESULTS OF STUDY : Basic mass - Concept overall scoringEn ligne : http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20120009204_2012009492.pdf Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=15610
in SAMPE JOURNAL > Vol. 48, N° 4 (07-08/2012) . - p. 40-48[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 14011 - Périodique Bibliothèque principale Documentaires Disponible
Titre : Microstrain distribution in composites : Digital image correlation Type de document : texte imprimé Auteurs : Ajay Godara, Auteur Année de publication : 2007 Article en page(s) : p. 108-110 Langues : Anglais (eng) Tags : 'Propriété mécanique' 'Fibre minérale' Polyoléfine 'Image numérique' 'Analyse image' 'Mesure déformation' Endommagement 'Intégrité structure' traction' verre' Polypropène 'Matériau renforcé fibre' composite' Index. décimale : 668.4 Plastiques, vinyles Résumé : In this study, tensile tests combined with the digital image correlation (DIC) technique have been used to investigate the structural integrity of thermoplastic matrix composites such as polypropylene with reinforcing E-glass fibres. The spatial distribution of the accumulated plastic surface strain was calculated using DIC, which is based on pattern recognition of the surface before and after straining. The results reveal a relationship between the heterogeneity of plastic surface microstrain and the underlying microstructure of the material. It is found that the surface mapping technique at mesoscale level can successfully identify the internal damage in terms of strain concentration. Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=14209
in JEC COMPOSITES MAGAZINE > N° 31 (03-04/2007) . - p. 108-110[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 006342 - Périodique Bibliothèque principale Documentaires Disponible
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