Bibliographies thématiques / Cyclic matrice

Sommaire

Articles de revues
Thèses
Livres
Chapitres de livres
Actes de conférences
Rapports d'organisations

Littérature scientifique sur le sujet « Cyclic matrice »

Auteur : Grafiati

Publié le 9 mars 2023

Mis à jour le 10 mars 2023

Créez une référence correcte selon les styles APA, MLA, Chicago, Harvard et plusieurs autres

Choisissez une source :

Consultez les listes thématiques d’articles de revues, de livres, de thèses, de rapports de conférences et d’autres sources académiques sur le sujet « Cyclic matrice ».

À côté de chaque source dans la liste de références il y a un bouton « Ajouter à la bibliographie ». Cliquez sur ce bouton, et nous générerons automatiquement la référence bibliographique pour la source choisie selon votre style de citation préféré : APA, MLA, Harvard, Vancouver, Chicago, etc.

Vous pouvez aussi télécharger le texte intégral de la publication scolaire au format pdf et consulter son résumé en ligne lorsque ces informations sont inclues dans les métadonnées.

Articles de revues sur le sujet "Cyclic matrice"

Uygun, Hilmiye Deniz Ertugrul, Nihat Tinkilic, Azade Attar et Ibrahim Isildak. « Development of Potentiometric Lactate Biosensor Based on Composite pH Sensor ». Journal of New Materials for Electrochemical Systems 19, n^o 3 (20 septembre 2016) : 151–56. http://dx.doi.org/10.14447/jnmes.v19i3.313.

Texte intégral

Résumé :

In this study, a micro-sized lactate sensitive biosensor based on polyvinylchloride, quinhydrone and graphite composite pH sensing platform was developed. Lactate oxidase was immobilized on the composite layer as the biorecognition element. Transformation reaction of lactate to pyruvate and hydrogen peroxide was the basis of this biosensor system. In the reaction, hydrogen peroxide undergoes to give hydronium ions into solution, and the pH sensitive membrane detects the adjunct hydronium ions potentiometrically. The surface of lactate biosensor based composite pH sensing matrice was first examined for electrochemical elucidation by using cyclic voltammetry and electrochemical impedance spectroscopy. A linear response in concentration range from 5x10-5 to 1x10-1 mol/L was obtained with a detec-tion limit of 2x10-5 mol/L. The lactate biosensor developed was successfully applied for highly precise and efficient determination of lactate in food preparations. The biosensor exhibited a fast response time (10 s), had good stability, and had an extended lifetime.

Styles APA, Harvard, Vancouver, ISO, etc.

Tarasov, Vitaly. « Cyclic monodromy matrices forsl(n) trigonometricR-matrices ». Communications in Mathematical Physics 158, n^o 3 (décembre 1993) : 459–83. http://dx.doi.org/10.1007/bf02096799.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Shinjo, Masato, Tan Wang, Masashi Iwasaki et Yoshimasa Nakamura. « Roots of Characteristic Polynomial Sequences in Iterative Block Cyclic Reductions ». Mathematics 9, n^o 24 (12 décembre 2021) : 3213. http://dx.doi.org/10.3390/math9243213.

Texte intégral

Résumé :

The block cyclic reduction method is a finite-step direct method used for solving linear systems with block tridiagonal coefficient matrices. It iteratively uses transformations to reduce the number of non-zero blocks in coefficient matrices. With repeated block cyclic reductions, non-zero off-diagonal blocks in coefficient matrices incrementally leave the diagonal blocks and eventually vanish after a finite number of block cyclic reductions. In this paper, we focus on the roots of characteristic polynomials of coefficient matrices that are repeatedly transformed by block cyclic reductions. We regard each block cyclic reduction as a composition of two types of matrix transformations, and then attempt to examine changes in the existence range of roots. This is a block extension of the idea presented in our previous papers on simple cyclic reductions. The property that the roots are not very scattered is a key to accurately solve linear systems in floating-point arithmetic. We clarify that block cyclic reductions do not disperse roots, but rather narrow their distribution, if the original coefficient matrix is symmetric positive or negative definite.

Styles APA, Harvard, Vancouver, ISO, etc.

Zheng, Yanpeng, et Xiaoyu Jiang. « Quasi-cyclic displacement and inversion decomposition of a quasi-Toeplitz matrix ». AIMS Mathematics 7, n^o 7 (2022) : 11647–62. http://dx.doi.org/10.3934/math.2022649.

Texte intégral

Résumé :

<abstract>We study a class of column upper-minus-lower (CUML) Toeplitz matrices, which are "close" to the Toeplitz matrices in the sense that their ($ 1, -1 $)-cyclic displacements coincide with $ \varphi $-cyclic displacement of some Toeplitz matrices. Among others, we derive the inverse formula for CUML Toeplitz matrices in the form of sums of products of factor circulants by constructing the corresponding displacement of the matrices. In addition, by the relationship between CUML Toeplitz matrices and CUML Hankel matrices, the inverse formula for CUML Hankel matrices is also obtained.</abstract>

Styles APA, Harvard, Vancouver, ISO, etc.

Neumann, Peter M., et Cheryl E. Praeger. « Cyclic Matrices Over Finite Fields ». Journal of the London Mathematical Society 52, n^o 2 (octobre 1995) : 263–84. http://dx.doi.org/10.1112/jlms/52.2.263.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Tam, Bit-Shun. « On matrices with cyclic structure ». Linear Algebra and its Applications 302-303 (décembre 1999) : 377–410. http://dx.doi.org/10.1016/s0024-3795(99)00097-x.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Riaza, Ricardo. « Cyclic matrices of weighted digraphs ». Discrete Applied Mathematics 160, n^o 3 (février 2012) : 280–90. http://dx.doi.org/10.1016/j.dam.2011.09.005.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Sergeev, A. « Interrelation of Symmetry and Antisymmetry of Quasi-Orthogonal Cyclic Matrices with Prime Numbers ». Proceedings of Telecommunication Universities 8, n^o 4 (5 janvier 2023) : 14–19. http://dx.doi.org/10.31854/1813-324x-2022-8-4-14-19.

Texte intégral

Résumé :

Quasi-orthogonal Hadamard matrices and Mersenne matrices with two and three values of the elements, used in digital data processing, are considered, as well as the basis of error-correcting codes and algorithms for transforming orthogonal images. Attention is paid to the structures of cyclic matrices with symmetries and antisymmetries. The connection between symmetry and antisymmetry of structures of cyclic Hadamard and Mersenne matrices on a orders equal to prime numbers, products of close primes, composite numbers, powers of a prime number is shown. Separately, orders equal to the degrees of the prime number 2 are distinguished, both the orders of Hadamard matrices and the basis of the composite orders of Mersenne matrices of block structures with two element values. It is shown that symmetric Hadamard matrices of cyclic and bicyclic structures, according to the extended Riser boundary, do not exist on orders above 32. Mersenne matrices of composite orders belonging to the sequence of Mersenne numbers 2k ‒ 1 nested in the sequence of orders of the main family of Mersenne matrices 4t ‒ 1 exist in a symmetric and antisymmetric form. For orders equal to the powers of a prime number, Mersenne matrices exist in the form of block-diagonal constructions with three element values. The value of prime power determines the number of blocks along the diagonal of the matrix on which the elements with the third value are located. The cyclic blocks are symmetrical and antisymmetric.

Styles APA, Harvard, Vancouver, ISO, etc.

Corr, Brian P., et Cheryl E. Praeger. « Primary cyclic matrices in irreducible matrix subalgebras ». Journal of Group Theory 21, n^o 4 (1 juillet 2018) : 667–94. http://dx.doi.org/10.1515/jgth-2018-0012.

Texte intégral

Résumé :

AbstractPrimary cyclic matrices were used (but not named) by Holt and Rees in their version of Parker’s MEAT-AXE algorithm to test irreducibility of finite matrix groups and algebras. They are matrices X with at least one cyclic component in the primary decomposition of the underlying vector space as an X-module. Let {\operatorname{M}(c,q^{b})} be an irreducible subalgebra of {\operatorname{M}(n,q)}, where {n=bc>c}. We prove a generalisation of the Kung–Stong cycle index theorem, and use it to obtain a lower bound for the proportion of primary cyclic matrices in {\operatorname{M}(c,q^{b})}. This extends work of Glasby and the second author on the case {b=1}.

Styles APA, Harvard, Vancouver, ISO, etc.

Deveci, Omur, Yesim Akuzum, Erdal Karaduman et Ozgur Erdag. « The Cyclic Groups via Bezout Matrices ». Journal of Mathematics Research 7, n^o 2 (22 mars 2015) : 34. http://dx.doi.org/10.5539/jmr.v7n2p34.

Texte intégral

Résumé :

In this paper, we define the Bezout matrices by the aid of the characteristic polynomials of the k-step Fibonacci, the generalized order-k Pell and the generalized order-k Jacobsthal sequences then we consider the multiplicative orders of the Bezout matrices when read modulo m. Consequently, we obtain the rules for the order of the cyclic groups by reducing the Bezout matrices modulo m.

Styles APA, Harvard, Vancouver, ISO, etc.

Plus de sources

Thèses sur le sujet "Cyclic matrice"

Godeau, Amélie. « Cyclic contractions contribute to 3D cell motility ». Thesis, Strasbourg, 2016. http://www.theses.fr/2016STRAF038/document.

Texte intégral

Résumé :

La motilité des cellules est un phénomène fondamental en biologie souvent étudié sur des surfaces planes, conditions peu physiologiques. Nous avons analysé la migration cellulaire dans une matrice cellulaire 3D contenant de la fibronectine fluorescente. Nous démontrons que les cellules y sont confinées, et déforment leur environnement de manière cyclique avec une période de ~14 min avec deux centres de contractions à l’avant et à l’arrière de la cellule qui contractent avec un déphasage de ~3.5 min. Une perturbation de ces cycles entraîne une réduction de la motilité. Par l’utilisation d’inhibiteurs spécifiques, nous avons identifié l’acto-myosine comme étant l’acteur principal de ce phénomène. En imposant des contractions-relaxations locales par ablations laser, nous avons déclenché la motilité cellulaire ce qui confirme notre hypothèse. L’ensemble de cette étude met en évidence un nouveau mécanisme fondamental de dynamique cellulaire impliqué dans le mouvement des cellules
Cell motility is an important process in Biology. It is mainly studied on 2D planar surfaces, whereas cells experience a confining 3D environment in vivo. We prepared a 3D Cell Derived Matrix (CDM) labeled with fluorescently labeled fibronectin, and strikingly cells managed to deform the matrix with specific patterns : contractions occur cyclically with two contraction centers at the front and at the back of the cell, with a period of ~14 min and a phase shift of ~3.5 min. These cycles enable cells to optimally migrate through the CDM, as perturbation of cycles led to reduced motility. Acto-myosin was established to be the driving actor of these cycles, by using specific inhibitors. We were able to trigger cell motility externally with local laser ablations, which supports this framework of two alternating contractions involved in motion. Altogether, this study reveals a new mechanism of dynamic cellular behaviour linked to cell motility

Styles APA, Harvard, Vancouver, ISO, etc.

Raud, Christophe. « Fissuration des composites carbone à matrice thermostable en traction isotherme et cyclage thermique ». Cachan, Ecole normale supérieure, 1993. http://www.theses.fr/1993DENS0013.

Texte intégral

Résumé :

Ce travail vise a mieux comprendre les phénomènes qui régissent la microfissuration des stratifies carbone/matrice organique thermostable. Deux matériaux représentatifs des classes de température 200-250c (t800/5250 et t800/pmr-15), élaborés suivant plusieurs conditions de moulage, ont été étudiés. Il s'agit de déterminer l'influence des paramètres de fabrication sur la sensibilité a la microfissuration d'un drapage modelé 0#2,90#2#s dans des conditions de chargement quasi-statiques (traction uniaxiale) ou en sollicitation thermique alternée : en isotherme, des essais en traction statique interrompus a niveaux de charge croissants ont été effectues a -110, 20# et 250c avec suivi d'endommagement par rayons x et émission acoustique. Les résultats rendent compte d'une hiérarchie des lois d'apparition de fissures en fonction des contraintes thermiques installées. Cette hiérarchie n'est pas remise en cause lorsqu'on modifie la température d'essai. Des modèles analytiques fondes sur un critère énergétique de rupture (Flaggs & Kural, Laws & Dvorak, Nairn) ont été appliques pour prévoir l'accumulation des fissures; des sollicitations thermiques alternées sans chargement mécanique ont été réalisées entre 110 et +250c avec suivi par rayons x et émission acoustique et des courbes d'accumulation de fissures obtenues en fonction du nombre de cycles. La température maximale atteinte au cours de la mise en œuvre gouverne le nombre de cycles nécessaire à l'apparition de la première fissure ainsi que l'état de fissuration final. On met en évidence l'importance de la partie froide du cycle et celle de la vitesse de refroidissement. Dans la limite du nombre d'alternances (n60) qui a pu être explore, l'extension de l'endommagement est seulement fonction de l'amplitude de température et peut être, en première analyse, traitée en termes d'équivalence thermique-mécanique, le rôle de la vitesse restant à préciser.

Styles APA, Harvard, Vancouver, ISO, etc.

Racle, Elie. « Comportement d'un composite à matrice céramique en fatigue et mise en place d'indicateurs d'endommagement par émission acoustique ». Thesis, Lyon, INSA, 2015. http://www.theses.fr/2015ISAL0071.

Texte intégral

Résumé :

La compréhension du comportement d'un composite à matrice céramique (CMC) lorsqu'il est sollicité en fatigue est l'un des points clés pour permettre son utilisation dans un cadre industriel. Il est en effet nécessaire de déterminer la chronologie des différents mécanismes d'endommagement ainsi que d'estimer la durée de vie en conditions d'utilisation. Il est alors nécessaire de réaliser une caractérisation mécanique mais aussi de définir des indicateurs d'endommagement permettant la prévision de durée de vie. Dans ce but, il est intéressant de coupler l'analyse des paramètres mécaniques et les observations microstructurales à des techniques de suivi en temps réel de l'endommagement. L'émission acoustique (EA) est une méthode de suivi non destructive qui permet de répondre à cette problématique. Elle permet notamment de quantifier et de localiser l'endommagement. Dans ce travail, de nouveaux indicateurs d'endommagement sont mis en place tels la "Sévérité" des signaux définie à partir de l'énergie acoustique ainsi que la "Sentry function" définie à partir de l'énergie acoustique et de l'énergie mécanique. Ce travail s'articule autour de deux principaux axes. Dans un premier temps il s'agit de caractériser les effets de la sollicitation cyclique sur ce type de matériau, ceci notamment en comparant l'évolution des paramètres mécaniques, les observations microstructurales ainsi que l’analyse de l'évolution globale de l'émission acoustique (EA) lorsque le matériau est soumis à un chargement statique et à un chargement cyclique. La seconde partie consiste à déterminer un scenario d'endommagement. Dans un premier temps, les signaux d’EA sont analysés en fonction de leur détection dans le cycle (charge/décharge). Ensuite la détermination de la signature acoustique des différents mécanismes d'endommagement par application de techniques de reconnaissance de formes supervisées a permis d'évaluer leur chronologie d'activation durant les essais de fatigue cyclique. Cette étude a permis de mettre en évidence un ensemble de mécanismes propres à la sollicitation cyclique, composé principalement de décohésion et de frottement aux interfaces fibre/matrice et matrice/matrice. De plus, l'utilisation de l'émission acoustique a permis de définir des temps caractéristiques ou critiques pouvant être utilisés dans un objectif de prévision de la durée de vie. En effet, par exemple la sévérité des signaux a permis de mettre en évidence un temps caractéristique situé entre 25 et 45% de la durée de vie du matériau. La détection en temps réel de ce temps caractéristique permet d'estimer la durée de vie restante
The full understanding of a ceramic matrix composite under fatigue loading is needed in view of industrial applications. It is necessary to determine the damage mechanisms chronology and to be able to forecast the lifetime of the material in the conditions of use. To reach these purposes, a mechanical characterisation has to be done as well as the definition of damage indicators. It is then interesting to link the analysis of mechanical parameters and microscope observations with a non-destructive monitoring technique. Acoustic emission (AE) appears to be a good candidate to monitor material damage under loading. It makes the quantification and the material damage localisation possible. In this study, indicators based on released acoustic energy are used as "Severity" of signals or "Sentry function" which depends on both acoustic and mechanical energies. This work is organised in two parts. First, the analysis of mechanical parameters behaviour, material microstructure and global evolution of acoustic emission under static and cyclic loading makes the characterisation of the effects of cyclic fatigue on the material possible. The second part consists in determining a damage scenario. First acoustic emission signals are analysed depending on their acquisition during a cycle (loading or unloading). Then the connection between the acoustic emission signals and the different damage mechanisms, using a supervised clustering method, facilitated the estimation of the activation of these different damage mechanisms during cyclic fatigue tests. This study pointed out different damage mechanisms generated by cyclic loading, which are mainly debonding and friction at matrix/fibre and matrix/matrix interfaces. In addition, damage indicators based on acoustic emission enabled to determine characteristic times which can be used for lifetime forecast. For example, signal severity shows a characteristic time between 25% and 45% of the time to ultimate failure. Detection of this time in real-time during a test can be used to estimate the time of the ultimate failure of the material

Styles APA, Harvard, Vancouver, ISO, etc.

DI, GRAVINA LUCA MARIA. « Some questions about the Möbius function of finite linear groups ». Doctoral thesis, Università degli Studi di Milano-Bicocca, 2022. http://hdl.handle.net/10281/371474.

Texte intégral

Résumé :

La funzione di Möbius definita per insiemi parzialmente ordinati localmente finiti è un classico strumento di analisi combinatoria. Si tratta di una generalizzazione della funzione di Möbius nota in teoria dei numeri e ha varie applicazioni pure in teoria dei gruppi, dalla caratteristica di Eulero di complessi di sottogruppi fino allo studio di aspetti algebrici in automi cellulari. Nella prima parte della tesi richiamiamo alcune informazioni elementari per strutture d'ordine che sono legate alla funzione di Möbius, e ne presentiamo le principali proprietà, quali ad esempio la formula di inversione di Möbius e i teoremi di Crapo. Inoltre analizziamo alcuni legami importanti con argomenti di teoria dei gruppi, al fine di motivare il nostro interesse nei confronti della funzione di Möbius di gruppi lineari finiti. Nella seconda parte, lavoriamo su questi gruppi per studiarne la funzione di Möbius e otteniamo risultati originali che si rivelano utili per calcolarla, nota la struttura di alcuni particolari reticoli di sottospazi associati ai sottogruppi. Vediamo in dettaglio il caso in cui abbiamo un reticolo di sottospazi distributivo. In seguito mostriamo un esempio di sottogruppo del gruppo lineare generale, tale che il reticolo di sottospazi associato al sottogruppo non è distributivo. In questo modo osserviamo che i nostri ragionamenti hanno una validità più ampia e possono essere applicati a situazioni differenti, sotto determinate condizioni. Nell'ultima parte della tesi, colleghiamo i risultati ottenuti in precedenza ad alcune questioni aperte che riguardano gruppi profiniti finitamente generati e gruppi finiti almost-simple, presentando un approccio originale al problema. Benché poi questo problema non venga completamente risolto, otteniamo degli utili risultati parziali che possono essere sviluppati in futuro.
The Möbius function of locally finite partially ordered sets is a classical tool in enumerative combinatorics. It is a generalization of the number-theoretic Möbius function and it has several applications in group theory, from the Euler characteristic of subgroup complexes to algebraic aspects of cellular automata. In the first part of the thesis, we recall some basic notions about the order structures which are related to the Möbius function, and we present its main properties, such as the Möbius inversion formula and Crapo's theorems. Moreover, we investigate some relevant connections with group-theoretical topics to motivate our interest in the Möbius function of finite linear groups. In the second part, we work on these groups to obtain information about their Möbius function, and our original results are useful to compute it if we know the structure of some special subspace lattices related to subgroups. We study in detail the case of distributive subspace lattices. Then we show an example of a subgroup in the general linear group, such that the subspace lattice associated to the subgroup is non-distributive. In this way, we see that our arguments can also be applied to different situations, under certain conditions. In the last part of the thesis, we connect the previously obtained results to an open question about finitely generated profinite groups and finite almost-simple groups, introducing an original approach to the problem. Although we do not completely answer to this last question, we get some useful partial results.

Styles APA, Harvard, Vancouver, ISO, etc.

Dridi, Marwa. « Sur les méthodes rapides de résolution de systèmes de Toeplitz bandes ». Thesis, Littoral, 2016. http://www.theses.fr/2016DUNK0402/document.

Texte intégral

Résumé :

Cette thèse vise à la conception de nouveaux algorithmes rapides en calcul numérique via les matrices de Toeplitz. Tout d'abord, nous avons introduit un algorithme rapide sur le calcul de l'inverse d'une matrice triangulaire de Toeplitz en se basant sur des notions d'interpolation polynomiale. Cet algorithme nécessitant uniquement deux FFT(2n) est manifestement efficace par rapport à ses prédécésseurs. ensuite, nous avons introduit un algorithme rapide pour la résolution d'un système linéaire de Toeplitz bande. Cette approche est basée sur l'extension de la matrice donnée par plusieurs lignes en dessus, de plusieurs colonnes à droite et d'attribuer des zéros et des constantes non nulles dans chacune de ces lignes et de ces colonnes de telle façon que la matrice augmentée à la structure d'une matrice triangulaire inférieure de Toeplitz. La stabilité de l'algorithme a été discutée et son efficacité a été aussi justifiée. Finalement, nous avons abordé la résolution d'un système de Toeplitz bandes par blocs bandes de Toeplitz. Ceci étant primordial pour établir la connexion de nos algorithmes à des applications en restauration d'images, un domaine phare en mathématiques appliquées
This thesis aims to design new fast algorithms for numerical computation via the Toeplitz matrices. First, we introduced a fast algorithm to compute the inverse of a triangular Toeplitz matrix with real and/or complex numbers based on polynomial interpolation techniques. This algorithm requires only two FFT (2n) is clearly effective compared to predecessors. A numerical accuracy and error analysis is also considered. Numerical examples are given to illustrate the effectiveness of our method. In addition, we introduced a fast algorithm for solving a linear banded Toeplitz system. This new approach is based on extending the given matrix with several rows on the top and several columns on the right and to assign zeros and some nonzero constants in each of these rows and columns in such a way that the augmented matrix has a lower triangular Toeplitz structure. Stability of the algorithm is discussed and its performance is showed by numerical experiments. This is essential to connect our algorithms to applications such as image restoration applications, a key area in applied mathematics

Styles APA, Harvard, Vancouver, ISO, etc.

Kahn, Cyril. « Ingénierie tissulaire des ligaments : conception d'un bioréacteur et étude des propriétés mécaniques ». Thesis, Vandoeuvre-les-Nancy, INPL, 2009. http://www.theses.fr/2009INPL010N/document.

Texte intégral

Résumé :

L’ingénierie tissulaire vise à l’élaboration de prothèses biologiques par la régénération ou la culture, in vitro ou in vivo, de tissus ou d’organes. Dans la stratégie de culture in vitro, le développement de nouveaux outils, tels que des bioréacteurs, permettant la culture de cellules ou de tissus sous sollicitations mécaniques spécifiques au tissu est primordial. De plus, l’avancée de cette discipline dans la régénération des tissus nécessite de développer, dès à présent, des méthodes d’évaluation mécanique satisfaisantes permettant de comparer ces néo-tissus aux tissus sains selon des critères de sollicitations physiologiques. En effet, pour parvenir à une bonne évaluation de ces matériaux, il est nécessaire de pouvoir les tester sur des chargements représentatifs des sollicitations physiologiques auxquelles ils sont soumis. Nous avons ainsi, dans un premier temps, conçu et développé un bioréacteur de ligaments permettant la culture de cellules stimulées mécaniquement par des sollicitations cycliques de traction-torsion. Ce bioréacteur a été dimensionné afin de pouvoir obtenir des bio-prothèses de taille comparable aux ligaments et tendons à remplacer (4 à 5 cm de long). Nous avons, dans un deuxième temps, développé un modèle du comportement mécanique global de ces tissus à partir du formalisme thermodynamique développé au sein de notre laboratoire et des observations faites sur des tendons d’Achille de lapin. Ce modèle a pour but d’approfondir la compréhension des structures intervenant de façon prépondérante dans la qualité mécanique de ces tissus ainsi que l’évaluation et l’optimisation des matrices de support et des néo-tissus devant s’y substituer
Tissue Engineering aims to fabricate bio-prostheses by regenerating or culture, in vivo or in vitro, tissues or organs. In the in vitro strategy, developing new tools such as bioréactors which allow the culture of cells or tissues under their specific mechanical solicitations is a huge point. Moreover, the last advances of this discipline in regeneration of tissues require new mechanical model allowing their evaluation and comparison to native tissue under physiological loading. Indeed, in order to obtain a good evaluation of their mechanical quality, it is important to be able to applied mechanical solicitations linked to physiological ones. As a first step, a bioreactor of ligament allowing the culture of cells under mechanical solicitations of cyclic traction-torsion was designed and developed. This bioreactor was sized to potentially obtain a bio-prosthesis comparable to native tissue in term of size (4 to 5 cm long). In a second time, a mechanical model was elaborated based on a thermodynamic formalism developed in our laboratory and the observation made on rabbit Achilles tendons. The goals of this model are to improve our knowledge on the mayor structures involved into the mechanical quality of theses tissues and to evaluate and optimise the scaffolds and neo-tissues of substitution

Styles APA, Harvard, Vancouver, ISO, etc.

吳堉榕 et Yuk-yung Ng. « Cyclic menon difference sets, circulant hadamard matrices and barker sequences ». Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1993. http://hub.hku.hk/bib/B31211823.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Ng, Yuk-yung. « Cyclic menon difference sets, circulant hadamard matrices and barker sequences / ». [Hong Kong] : University of Hong Kong, 1993. http://sunzi.lib.hku.hk/hkuto/record.jsp?B13814291.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Craciun, Ovidiu Engineering &amp Information Technology Australian Defence Force Academy UNSW. « Matric suction response of unbound granular base materials subject to cyclic loading ». Awarded by:University of New South Wales - Australian Defence Force Academy. Engineering & ; Information Technology, 2009. http://handle.unsw.edu.au/1959.4/43927.

Texte intégral

Résumé :

The emergence of analytically-based pavement design has encouraged investigations toward a better understanding of the behaviour of pavement layers under cyclic loading. Unbound granular base (UGB) materials are commonly placed as base course layers in the design of pavement foundations. Due to their nature and geometry they are unsaturated geo-materials and therefore, it is desirable to study their behaviour using the framework of unsaturated soil mechanics. Current literature reflects very limited achievements in this direction. This thesis presents the development of a cyclic triaxial testing system and associated testing methodology that meets the challenges of testing an UGB material as an unsaturated soil. The testing system enables the initialisation of a specimen to target matric suction and facilitates direct measurement of its evolution under cyclic loading. In conjunction with the use of accurate on-specimens strain measurement transducers, ???clean??? strain and matric suction cyclic responses are obtained. Two types of cyclic triaxial testing are investigated: with constant cell pressure (i.e., CSeries testing) and with varying (cyclic) cell pressure where both axial and radial stress components are simultaneously (and in phase) pulsed (i.e., V-Series testing). Different initial matric suctions, si will be imposed in the testing program and the influence of si on material behaviour is analysed. This is investigated in a similar manner for C- and V-Series testing. The influence of si appears to be significant for both cyclic and permanent strain responses. A strong stress path dependency is found to characterise the behaviour of the UGB material. Under a wide range of cyclic deviator stress magnitudes, permanent strain response is found to correlate with that of matric suction response. Both appear to indicate better the relative performance of a UGB material than the response of resilient modulus. Another particular aspect investigated is the influence of additional fines on the behaviour of the UGB material. To ???isolate??? the effects of additional fines the cyclic and permanent strain responses of ???equivalent??? specimens with equivalent compaction and unsaturation condition, but different fines content, are compared. The results showed that the relative performance of the two materials (distinguished by the different percentage of fines content) in intertwined with the strong stress path dependency. It is also found that a material compacted at higher dry density may not improve its behaviour under cyclic loading, but may worsen with load cycles. Soil-water characteristic curve tests are conducted for the UGB materials investigated, showing high sensitivity of initial matric suction to moisture content, which increases further for the material with additional fines. This explains the notion of ???sensitivity??? of UGB materials as commonly suggested by practicing pavement engineers.

Styles APA, Harvard, Vancouver, ISO, etc.

Praud, Francis. « Multi-scale modelling of thermoplastic-based woven composites, cyclic and time-dependent behaviour ». Thesis, Paris, ENSAM, 2018. http://www.theses.fr/2018ENAM0018/document.

Texte intégral

Résumé :

Dans ce travail de thèse, une modélisation multi-échelle est mise en place à partir du concept d’homogénéisation périodique pour étudier le comportement cyclique et dépendant du temps des composites tissés à matrice thermoplastique. Avec l’approche proposée, le comportement macroscopique du composite est déterminé à partir d’une simulation éléments finis effectuée sur une cellule unitaire représentative de la microstructure périodique, où les lois de comportement des constituants sont directement intégrées, à savoir: la matrice et les torons. La réponse locale de la matrice est décrite par une loi de comportement phénoménologique multi-mécanismes intégrant viscoélasticité, viscoplasticité et endommagement ductile. Pour les torons, une loi de comportement hybride micromécanique-phénoménologique est considérée. Cette dernière prend en compte l’endommagement anisotrope et l’anélasticité induite par la présence d’un réseau diffus de microfissures à travers une description micromécanique d’un volume élémentaire représentatif contenant des microfissures. Les capacités du modèle multi-échelles sont validées en comparant les prédictions numériques aux essais expérimentaux. Les capacités du modèle sont également illustrées à travers plusieurs exemples où le composite subit des déformations dépendantes du temps lors de chargements monotones, de chargements à amplitude constante ou cyclique et encore lors de chargement multiaxiaux non proportionnels. En outre, le modèle multi-échelle est aussi utilisé pour analyser l’influence des mécanismes de déformation locaux sur la réponse macroscopique du composite
In this thesis, a multi-scale model established from the concept of periodic homogenization is utilized to study the cyclic and time-dependent response of thermoplastic-based woven composites. With the proposed approach, the macroscopic behaviour of the composite is determined from a finite element simulation of the representative unit cell of the periodic microstructure, where the local constitutive behaviours of the components are directly integrated, namely: the matrix and the yarns. The local response of the thermoplastic matrix is described by a phenomenological multi-mechanisms constitutive model accounting for viscoelasticity, viscoplasticity and ductile damage. For the yarns, a hybrid micromechanical-phenomenological constitutive model is considered. The latter accounts for anisotropic damage and anelasticity induced by the presence of a diffuse micro-crack network through the micromechanical description of a micro-cracked representative volume element. The capabilities of the multi-scale model are validated by comparing the numerical prediction with experimental data. The capabilities of the model are also illustrated through several examples where the composite undergoes time-dependent deformations under monotonic loading, constant or cyclic stress levels and non-proportional multi-axial loading. Furthermore, the multi-scale model is also employed to analyse the influence of the local deformation processes on the macroscopic response of the composite

Styles APA, Harvard, Vancouver, ISO, etc.

Plus de sources

Livres sur le sujet "Cyclic matrice"

R, Johnson Charles, et Loewy Raphael 1943-, dir. The real positive definite completion problem : Cycle completability. Providence, R.I : American Mathematical Society, 1996.

Trouver le texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

N, Lee Kang, Miller Robert A. 1947- et NASA Glenn Research Center, dir. Thermal conductivity and thermal gradient cyclic behavior of refractory silicate coatings on SiC/SiC ceramic matrix composites. [Cleveland, Ohio] : National Aeronautics and Space Administration, Glenn Research Center, 2001.

Trouver le texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Castelli, Michael G. Characterization of damage progression in SCS-6/Timetal 21S [0]₄ under thermomechanical fatigue loadings. [Washington, DC] : National Aeronautics and Space Administration, 1994.

Trouver le texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Heijungs, Reinout. The Computational Structure of Life Cycle Assessment. Dordrecht : Springer Netherlands, 2002.

Trouver le texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Analyse matricielle, cours et exercices résolus : Deuxième cycle universitaire, agrégation. Les Ulis : EDP Sciences, 1999.

Trouver le texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

S, Majumdar Bhaskar, et United States. National Aeronautics and Space Administration., dir. In-phase thermomechanical fatigue mechanisms in an unidirectional SCS-6/Ti 15-3 MMC. [Washington, DC] : National Aeronautics and Space Administration, 1995.

Trouver le texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Trouver le texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Trouver le texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Kevin, O'Brien T., Rousseau Carl Q et United States. National Aeronautics and Space Administration., dir. Fatigue life methodology for tapered composite flexbeam laminates. [Washington, DC : National Aeronautics and Space Administration, 1997.

Trouver le texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Kevin, O'Brien T., Rousseau Carl Q et Langley Research Center, dir. Fatigue life methodology for tapered composite flexbeam laminates. Hampton, Va : National Aeronautics and Space Administration, Langley Research Center, 1997.

Trouver le texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Plus de sources

Chapitres de livres sur le sujet "Cyclic matrice"

Chawla, Nikhilesh, et Krishan K. Chawla. « Cyclic Fatigue ». Dans Metal Matrix Composites, 227–82. New York, NY : Springer New York, 2013. http://dx.doi.org/10.1007/978-1-4614-9548-2_8.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Chawla, K. K. « Mechanical behavior : load transfer ; monotonic, cyclic and creep behavior ». Dans Ceramic Matrix Composites, 224–73. Boston, MA : Springer US, 1993. http://dx.doi.org/10.1007/978-1-4757-2216-1_7.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Chawla, K. K. « Mechanical Behavior : Load Transfer ; Monotonic, Cyclic, and Creep Behavior ». Dans Ceramic Matrix Composites, 205–61. Boston, MA : Springer US, 2003. http://dx.doi.org/10.1007/978-1-4615-1029-1_7.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Rouby, D., O. Penas et P. Reynaud. « Anelastic Behaviour of Ceramic Matrix Composites during Cyclic Fatigue ». Dans High Temperature Ceramic Matrix Composites, 427–39. Weinheim, FRG : Wiley-VCH Verlag GmbH & Co. KGaA, 2006. http://dx.doi.org/10.1002/3527605622.ch68.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Lickorish, W. B. Raymond. « Cyclic Branched Covers and the Goeritz Matrix ». Dans An Introduction to Knot Theory, 93–102. New York, NY : Springer New York, 1997. http://dx.doi.org/10.1007/978-1-4612-0691-0_9.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Vulfson, Iosif. « Vibration Analysis of Cyclic Machines Using Modified Transition Matrices ». Dans Foundations of Engineering Mechanics, 247–65. Cham : Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-12634-0_8.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Zheng, Zhiyong, Kun Tian et Fengxia Liu. « Cyclic Lattices and Ideal Lattices ». Dans Financial Mathematics and Fintech, 119–42. Singapore : Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-7644-5_5.

Texte intégral

Résumé :

AbstractCyclic lattices and ideal lattices were introduced by Micciancio in [45], Lyubashevsky and Micciancio in [40], respectively, which play an efficient role in Ajtai’s construction of a collision-resistant Hash function and in Gentry’s construction of fully homomorphic encryption [22]. Let $$R=\mathbb {Z}[x]/<\phi (x)>$$ be a quotient ring of the integer coefficients polynomials ring, Lyubashevsky and Micciancio regarded an ideal lattice as the correspondence of an ideal of R, but they neither explain how to extend this definition to whole Euclidean space $$\mathbb {R}^n$$, nor exhibit the relationship of cyclic lattices and ideal lattices. In this chapter, we regard the cyclic lattices and ideal lattices as the correspondences of finitely generated R-modules, so that we may show that ideal lattices are actually a special subclass of cyclic lattices, namely cyclic integer lattices. It is worth noting that we use more general rotation matrix here, so our definition and results on cyclic lattices and ideal lattices are more general forms. As application, we provide cyclic lattice with an explicit and countable upper bound for the smoothing parameter. Our results may be viewed as a substantial progress in this direction.

Styles APA, Harvard, Vancouver, ISO, etc.

Voyiadjis, George Z., et Ganesh Thiagarajan. « A Cyclic Plasticity Model For Metal Matrix Composites ». Dans Computational Mechanics ’95, 1739–44. Berlin, Heidelberg : Springer Berlin Heidelberg, 1995. http://dx.doi.org/10.1007/978-3-642-79654-8_283.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Li, Longbiao. « Cyclic-Dependent Vibration Damping of Ceramic-Matrix Composites ». Dans Advanced Ceramics and Composites, 105–24. Singapore : Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-7838-8_6.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Audit, Philippe. « Use of Cyclic Matrices to Obtain Analytic Expressions for Crystals ». Dans Springer Series in Solid-State Sciences, 91–101. Berlin, Heidelberg : Springer Berlin Heidelberg, 1987. http://dx.doi.org/10.1007/978-3-642-82444-9_9.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Actes de conférences sur le sujet "Cyclic matrice"

Mazumder, Golam Rakib, Mohammad Ashraful Haq, Jeffrey C. Suhling et Pradeep Lall. « Effects of Mechanical Cycling Induced Damage on the Creep Response of SAC305 Solder ». Dans ASME 2022 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/ipack2022-93878.

Texte intégral

Résumé :

Abstract In electronic packaging, lead-free solders often experience fatigue failures due to thermal-mechanical cyclic stress and strain caused by changing temperatures and mismatches in thermal expansion coefficients. As a result, damage accumulates in the solder joints including plastic deformation, crack initiation, crack propagation, and finally failure occur. In our previous work, changes in the mechanical behavior of SAC305 lead free solder due to prior damage accumulation was investigated. Circular cross-section solder specimens were first reflowed, and these samples were then mechanically cycled for various durations using a Micro-Mechanical tester. Monotonic stress-strain tests were subsequently conducted on the prior cycled samples to characterize the change in mechanical behavior occurring in the solder due to damage accumulation. Using the data from these tests, we were able to characterize and quantify the cycling induced damage through the observed degradations of several mechanical properties (initial elastic modulus, yield stress, and ultimate tensile strength) with the amount of prior cycling. In the current work, we have extended the experimental work in our prior studies on SAC305 to examine the evolution of the creep response due to prior damage accumulation. In the experimental testing, small uniaxial cylindrical samples of SAC305 solder were prepared and reflowed in a reflow oven. These specimens were then mechanically cycled under several different sets of conditions to induce various levels of damage in the samples. In particular, four levels of initial damage per cycle were considered (ΔW = 0.25, 0.50, 0.75 and 1.00 MJ/m3), as well as three cycling temperatures (T = 25, 100, and 125 °C). For each of these damage levels per cycle, various durations of cycling were applied (e.g., 0, 50, 100, 300, and 600 cycles). This test matrix generated a large set of prior damaged samples, where the damage had been accumulated at different rates (different damage amounts per cycle), different cycling temperatures, and for different durations. In this paper, selected results obtained for isothermal mechanical cycling at T = 25 °C will be presented in detail. Creep tests were performed on the prior damage samples at room temperature and several stress levels including σ = 10.0, 12.0, and 15.0 MPa. The changes in the steady state secondary creep rate were then evaluated and plotted versus the duration of cycling for the various applied levels of damage per cycle. Exponential empirical models were found to fit the material property degradations well for any one set of conditions. More importantly, it was found that the total energy dissipation that had occurred in the sample (sum of ΔW for all cycles) could be used as a governing failure variable independent of the damage level applied during each cycle. In particular, all of the creep rate data for a selected stress level were modeled well using a single degradation curve independent of that rate the damage was accumulated. Using the results of this study, we are working to develop better damage mechanics models and fatigue criteria for lead free solders that are subjected to variable temperature applications.

Styles APA, Harvard, Vancouver, ISO, etc.

Alieva, Tatiana, et Martin J. Bastiaans. « Powers of transfer matrices and cyclic cascades ». Dans ICO XVIII 18th Congress of the International Commission for Optics, sous la direction de Alexander J. Glass, Joseph W. Goodman, Milton Chang, Arthur H. Guenther et Toshimitsu Asakura. SPIE, 1999. http://dx.doi.org/10.1117/12.355031.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Sharma, Pradeep, et Abhijit Dasgupta. « The Connection Between Microstructural Damage Modeling and Continuum Damage Modeling for Eutectic Sn-Pb Solder Alloys ». Dans ASME 2002 International Mechanical Engineering Congress and Exposition. ASMEDC, 2002. http://dx.doi.org/10.1115/imece2002-39185.

Texte intégral

Résumé :

Researchers resort to a wide range of simplified representations at the continuum scale, to model creep-fatigue damage in viscoplastic heterogeneous materials such as Sn-Pb eutectic solders, caused by thermo-mechanical and mechanical cyclic loading (e.g. due to power cycling, environmental temperature cycling, vibration, etc). Typically, in macroscale phenomenological damage models, the cyclic damage is assumed to depend on some loading parameter such as cyclic strain range, work dissipation per cycle, partitioned strain range, partitioned work dissipation per cycle, cyclic entropy changes, cyclic stress range, integrated matrix creep, etc. In many instances, some of these variables are weighted with a factor to account for rate-dependent effects. The task of finding the best damage metric is difficult because of complex microstructural interactions between cyclic creep and cyclic plasticity due to the high homologous temperature under operating conditions. In this study we use insights obtained from microstructural and more mechanistic modeling to identify the most appropriate macro-scale damage metrics. The microstructural models are based on such phenomena as grain boundary sliding, blocking of grain boundary sliding by second-phase particles, grain boundary, volumetric and surface diffusion, void nucleation, void growth and plastic collapse of cavitating grain boundaries. As has been demonstrated in the literature, microstructural models suggest that fatigue damage caused by cyclic plasticity should correlate well with the two most commonly used damage indicators: both cyclic strain range and plastic work dissipation per cycle. This study, however, demonstrates that in the case of damage dominated by cyclic creep, microstructural models developed by the authors indicate closer correlation with creep work dissipation per cycle, than with cyclic creep strain range.

Styles APA, Harvard, Vancouver, ISO, etc.

Xu, Guangjie, Huali Wang, Weijun Zeng, Qingguo Wang et Jun Jin. « Compressed sampling using structurally mixed cyclic measurement matrices ». Dans 2014 Sixth International Conference on Wireless Communications and Signal Processing (WCSP). IEEE, 2014. http://dx.doi.org/10.1109/wcsp.2014.6992206.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Matyushkin, Igor, et Pavel Rubis. « CELLULAR AUTOMATA ALGORITHMS FOR PSEUDORANDOM NUMBERS GENERATION ». Dans International Forum “Microelectronics – 2020”. Joung Scientists Scholarship “Microelectronics – 2020”. XIII International conference «Silicon – 2020». XII young scientists scholarship for silicon nanostructures and devices physics, material science, process and analysis. LLC MAKS Press, 2020. http://dx.doi.org/10.29003/m1648.silicon-2020/354-357.

Texte intégral

Résumé :

Work describes four permutation algorithms of square matrices based on cyclic rows and columns shifts. This choice of discrete transformation algorithms is justified by the convenience of the cellular automaton (CA) formulation. Output matrices can be considered as pseudo-random sequences of numbers. As a result of numerical calculation, empirical formulas are obtained for the permutation period and the function of the period of a single CA-cell on the order of the matrix n. As a parameter of CA dynamics, we analyze two "mixing metrics" on permutations of the matrix (compared to the initial matrix).

Styles APA, Harvard, Vancouver, ISO, etc.

Tondon, Abhishek, Hui-Ju Hsu et Roland Kaunas. « The Direction of Cyclic Stretch-Induced Stress Fiber Orientation Depends on Matrix Rigidity ». Dans ASME 2011 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2011. http://dx.doi.org/10.1115/sbc2011-53501.

Texte intégral

Résumé :

Mechanical properties of the cellular environment such as elastic rigidity have been shown to play an important role in the regulation of important cellular processes such as proliferation, differentiation and apoptosis (1–3). Intracellular tension decreases with decreasing matrix rigidity (1). Actin stress fibers (SFs), the major structural element in cells bearing tension, are also less prevalent on soft vs. rigid matrices (4). We have developed a theoretical model of stretch-induced SFs that predicts SFs reorient perpendicular to the direction of cyclic stretch in order to maintain SF tension at a homeostatic level (5). A theoretical model developed by the Safran group (6) predicts that cells will also align perpendicular to cyclic stretch on soft substrates. To test these predictions, we subjected cells to cyclic uniaxial stretch on soft collagen hydrogels. Interestingly, the cells and their SFs aligned parallel to the direction of stretch without co-alignment of collagen fibrils, indicating the need for a new model to describe the effects of cyclic stretch on SF reorganization on soft matrices.

Styles APA, Harvard, Vancouver, ISO, etc.

Potter, L. C., et D. Chiang. « Distance matrices and modified cyclic projections for molecular conformation ». Dans [Proceedings] ICASSP-92 : 1992 IEEE International Conference on Acoustics, Speech, and Signal Processing. IEEE, 1992. http://dx.doi.org/10.1109/icassp.1992.226458.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Jang, Ji-woong, Jae-dong Yang, Jong-seon No et Habong Chung. « New Construction of Balanced Quasi-Cyclic Generalized Hadamard Matrices ». Dans 2006 IEEE International Symposium on Information Theory. IEEE, 2006. http://dx.doi.org/10.1109/isit.2006.261603.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Baratta, Mirko, Stefano d’Ambrosio, Ezio Spessa et Alberto Vassallo. « Analysis of Cyclic Variability in a Bi-Fuel Engine by Means of a ‘Cycle-Resolved’ Diagnostic Technique ». Dans ASME 2005 Internal Combustion Engine Division Fall Technical Conference. ASMEDC, 2005. http://dx.doi.org/10.1115/icef2005-1214.

Texte intégral

Résumé :

The paper investigates cyclic variability in a fast-burn engine running on both gasoline or CNG by applying a new diagnostic technique based on a quasi-dimensional multizone model. Two different procedures were proposed for the ‘cycle-resolved’ calibration of the heat transfer correlation in the multizone model. The first procedure relates the cycle-resolved unreleased energy of the charge at the end of the flame propagation to the combustion efficiency determined from the average exhaust gas composition. The second procedure evaluates the coefficient in the heat transfer correlation through the application of the overall energy balance to the ensemble-cycle combustion and keeps them unchanged for all cycles. Both methods gave similar results, though the second procedure showed to be more physically consistent and in better agreement with the experimental results reported in the literature. The experimental matrix covered different engine speeds (n = 2000–4600 rpm), loads (bmep = 200–790 kPa), relative air-fuel ratios (RAFR = 0.80–1.60) and spark advances (SA ranging from 8 deg retard to 2 deg advance from MBT), for both CNG and gasoline operations, 100 consecutive in-cylinder pressure cycles were analyzed for each point in the test matrix and the sensitivity to cyclic variability of pressure, burn-rate and flame front position related parameters was analyzed. Main results showed that maximum pressure derivative, delay from SA of detected combustion start, NO exhaust concentration and maximum burning speed were the most sensitive parameters to cyclic variability. Strong correlations were found to hold between PFP and burned-gas temperature peak value, as well as between peak values of HRR and burning speed. On the contrary, some seemingly reasonable correlations were not assessed: for example, delay from SA of detected combustion start is related neither with PFP value nor with combustion duration. Finally, the results from mean cycle and cycle-resolved calculations were compared. Though they were usually in good agreement, in the case of NO emission and combustion interval calculation. cycle-resolved approach results in improved accuracy.

Styles APA, Harvard, Vancouver, ISO, etc.

Aksoy, S. « Thermomechanical Damage Development in SiC(SCS6)/Ti-6-4 Metal Matrix Composite ». Dans ASME 1992 International Gas Turbine and Aeroengine Congress and Exposition. American Society of Mechanical Engineers, 1992. http://dx.doi.org/10.1115/92-gt-342.

Texte intégral

Résumé :

A series of experiments were conducted to investigate the thermomechanical fatigue behavior of SiC(SCS-6)/Ti-6-4 composite. Three types of tests were conducted. In the first, specimens were subjected to load-controlled mechanical cycling under isothermal conditions. The other two types of test involved simultaneous cycling of load and temperature: in-phase and out-of-phase cycles. The effect of temperature cyclic ranges of 250°C to 528°C were evaluated for the out-of-phase (low temperature-high stress) conditions. A single temperature range of 250°C was employed for the in-phase (high temperature-high stress) condition. Fatigue-life diagrams were developed to evaluate the fatigue performance of the composite based on certain damage mechanism maps. In addition, micromechanical stresses in the fiber and matrix were computed using a generalized plane strain finite element analysis. The intention of this analytical effort was to provide the understanding of the fundamental mechanisms governing material behavior for guiding the development of life prediction methodology.

Styles APA, Harvard, Vancouver, ISO, etc.

Rapports d'organisations sur le sujet "Cyclic matrice"

Kinikles, Dellena, et John McCartney. Hyperbolic Hydro-mechanical Model for Seismic Compression Prediction of Unsaturated Soils in the Funicular Regime. Pacific Earthquake Engineering Research Center, University of California, Berkeley, CA, décembre 2022. http://dx.doi.org/10.55461/yunw7668.

Texte intégral

Résumé :

A semi-empirical elasto-plastic constitutive model with a hyperbolic stress-strain curve was developed with the goal of predicting the seismic compression of unsaturated sands in the funicular regime of the soil-water retention curve (SWRC) during undrained cyclic shearing. Using a flow rule derived from energy considerations, the evolution in plastic volumetric strain (seismic compression) was predicted from the plastic shear strains of the hysteretic hyperbolic stress-strain curve. The plastic volumetric strains are used to predict the changes in degree of saturation from phase relationships and changes in pore air pressure from Boyle’s and Henry’s laws. The degree of saturation was used to estimate changes in matric suction from the transient scanning paths of the SWRC. Changes in small-strain shear modulus estimated from changes in mean effective stress computed from the constant total stress and changes in pore air pressure, degree of saturation and matric suction, in turn affect the hyperbolic stress-strain curve’s shape and the evolution in plastic volumetric strain. The model was calibrated using experimental shear stress-strain backbone curves from drained cyclic simple shear tests and transient SWRC scanning path measurements from undrained cyclic simple shear tests. Then the model predictions were validated using experimental data from undrained cyclic simple shear tests on unsaturated sand specimens with different initial degrees of saturation in the funicular regime. While the model captured the coupled evolution in hydro-mechanical variables (pore air pressure, pore water pressure, matric suction, degree of saturation, volumetric strain, effective stress, shear modulus) well over the first 15 cycles of shearing, the predictions were less accurate after continued cyclic shearing up to 200 cycles. After large numbers of cycles of undrained shearing, a linear decreasing trend between seismic compression and initial degree of saturation was predicted from the model while a nonlinear increasing-decreasing trend was observed in the cyclic simple shear experiments. This discrepancy may be due to not considering post shearing reconsolidation in the model, calibration of model parameters, or experimental issues including a drift in the position of the hysteretic shear-stress strain curve. Nonetheless, the trend from the model is consistent with predictions from previously- developed empirical models in the funicular regime of the SWRC. The developments of the new mechanistic model developed in this study will play a key role in the future development of a holistic model for predicting the seismic compression across all regimes of the SWRC.

Styles APA, Harvard, Vancouver, ISO, etc.

Maydykovskiy, Igor. Consciousness as a new form of the matter’s state. Intellectual Archive, août 2021. http://dx.doi.org/10.32370/iaj.2555.

Texte intégral

Résumé :

The article discusses the physical model of the implicative form of Consciousness in the form of a holographic wave matrix, for which the material basis is directly the phase environment that fills the entire Space. It is shown that a similar form of Consciousness that exists outside the human brain can be represented as a kind of software shell that controls all forms of matter by implementing a fractal cyclic iterative algorithm. The condition for the completion of each iterative cycle at each scale level is the observance of the laws of symmetry that ensure the survival of the object in the process of copying-incarnation.

Styles APA, Harvard, Vancouver, ISO, etc.

White, Kenneth W. Modeling of Failure in Monolithic and Ceramic Matrix Composite Under Static and Cyclic Loading. Fort Belvoir, VA : Defense Technical Information Center, juillet 2004. http://dx.doi.org/10.21236/ada430835.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Taya, M., M. S. Lui, W. D. Armstrong et M. L. Dunn. Damage Accumulation in Advanced Metal Matrix Composites Under Thermal Cycling/Creep Loadings. Fort Belvoir, VA : Defense Technical Information Center, septembre 1993. http://dx.doi.org/10.21236/ada271207.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Morrison, Jay. Ceramic Matrix Composite Advanced Transition for 65% Combined Cycle Efficiency Turbines - Final Report. Office of Scientific and Technical Information (OSTI), août 2018. http://dx.doi.org/10.2172/1492685.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Shpigel, Muki, Allen Place, William Koven, Oded (Odi) Zmora, Sheenan Harpaz et Mordechai Harel. Development of Sodium Alginate Encapsulation of Diatom Concentrates as a Nutrient Delivery System to Enhance Growth and Survival of Post-Larvae Abalone. United States Department of Agriculture, septembre 2001. http://dx.doi.org/10.32747/2001.7586480.bard.

Texte intégral

Résumé :

The major bottlenecks in rearing the highly priced gastropod abalone (Haliotis spp.) are the slow growth rate and the high mortality during the first 8 to 12 weeks following metamorphosis and settling. The most likely reason flor these problems is related to nutritional deficiencies in the diatom diet on which the post larvae (PL) feed almost exclusively in captivity. Higher survival and improved growth rate will reduce the considerable expense of hatchery-nursery resisdence time and thereflore the production costs. BARD supported our research for one year only and the support was given to us in order to prove that "(1) Abalone PL feed on encapsulated diatoms, and (2) heterotrophic diatoms can be mass produced." In the course of this year we have developed a novel nutrient delivery system specifically designed to enhance growth and survival of post-larval abalone. This approach is based on the sodium-alginate encapsulation of heterotrophically grown diatoms or diatom extracts, including appetite-stimulating factors. Diatom species that attract the PL and promote the highest growth and survival have been identified. These were also tested by incorporating them (either intact cells or as cell extracts) into a sodium-alginate matrix while comparing the growth to that achieved when using diatoms (singel sp. or as a mixture). A number of potential chemoattractants to act as appetite-stimulating factors for abalone PL have been tested. Preliminary results show that the incorporation of the amino acid methionine at a level of 10-3M to the sodim alginate matrix leads to a marked enhancement of growth. The results ol these studies provided basic knowledge on the growth of abalone and showed that it is possible to obtain, on a regular basis, survival rates exceeding 10% for this stage. Prior to this study the survival rates ranged between 2-4%, less than half of the values achieved today. Several diatom species originated from the National Center for Mariculture (Nitzchia laevis, Navicula lenzi, Amphora T3, and Navicula tennerima) and Cylindrotheca fusiformis (2083, 2084, 2085, 2086 and 2087 UTEX strains, Austin TX) were tested for heterotrophic growth. Axenic colonies were initially obtained and following intensive selection cycles and mutagenesis treatments, Amphora T3, Navicula tennerima and Cylindrotheca fusiformis (2083 UTEX strain) were capable of growing under heterotrophic conditions and to sustain highly enriched mediums. A highly efficient selection procedure as well as cost effective matrix of media components were developed and optimized. Glucose was identified as the best carbon source for all diatom strains. Doubling times ranging from 20-40 h were observed, and stable heterotroph cultures at a densities range of 103-104 were achieved. Although current growth rates are not yet sufficient for full economical fermentation, we estimate that further selections and mutagenesis treatments cycles should result in much faster growing colonies suitable for a fermentor scale-up. As rightfully pointed out by one of the reviewers, "There would be no point in assessing the optimum levels of dietary inclusions into micro-capsules, if the post-larvae cannot be induced to consume those capsules in the first place." We believe that the results of the first year of research provide a foundationfor the continuation of this research following the objectives put forth in the original proposal. Future work should concentrate on the optimization of incorporation of intact cells and cell extracts of the developed heterotrophic strains in the alginate matrix, as well as improving this delivery system by including liposomes and chemoattractants to ensure food consumption and enhanced growth.

Styles APA, Harvard, Vancouver, ISO, etc.

Rodrigo, Maria Fernanda, Claudia Figueroa, Oliver Peña-Habib, Xiomara Rojas-Asqui et Melanie Putic. OVE's Review of Project Completion Reports (PCRs) and Expanded Supervision Reports (XSRs) : The 2020 Validation Cycle. Inter-American Development Bank, novembre 2020. http://dx.doi.org/10.18235/0002944.

Texte intégral

Résumé :

This report summarizes the results of the Office of Evaluation and Oversight's (OVE) annual validation of the self-assessments of project performance and results completed by the Inter-American Development Bank (IDB) and IDB Invest in 2019-2020. The IDB and IDB Invest have systems in place to measure the development effectiveness of their operations. These systems use a number of instruments to assess projects at the design, implementation, and completion phases. The design-phase assessment uses a “Development Effectiveness Matrix” (DEM) for sovereign guaranteed (SG) operations. The effectiveness of non-sovereign guaranteed (NSG) operations is measured with a “Development Effectiveness Learning, Tracking, and Assessment tool” (DELTA). Implementation-phase assessments measure SG operations with “Project Monitoring Reports,” while NSG operations are assessed with “Project Supervision Reports.” Upon completion, SG projects are self-evaluated with “Project Completion Reports,” or PCRs. NSG operations, use “Expanded Supervision Reports,” or XSRs when they reach early operation maturity (EOM). OVE validates Managements self-evaluations (PCRs and XSRs) and assigns a final project performance rating to each operation. As part of the 2020 validation cycle, OVE reviewed PCRs for 63 operations, 62 with operational closure (CO fully justified) in 2018 and one in 2013. XSRs were reviewed for 36 IDB Invest operations that had reached early operating maturity (EOM) in 2018.

Styles APA, Harvard, Vancouver, ISO, etc.

Grummon, D. S., et G. Gottstein. Softening mechanisms and microstructural instabilities during high temperature, low cycle fatigue of Ni, Ni sub 3 Al and their metal matrix composites. Office of Scientific and Technical Information (OSTI), janvier 1989. http://dx.doi.org/10.2172/5050198.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Al-Qadi, Imad, Jaime Hernandez, Angeli Jayme, Mojtaba Ziyadi, Erman Gungor, Seunggu Kang, John Harvey et al. The Impact of Wide-Base Tires on Pavement—A National Study. Illinois Center for Transportation, octobre 2021. http://dx.doi.org/10.36501/0197-9191/21-035.

Texte intégral

Résumé :

Researchers have been studying wide-base tires for over two decades, but no evidence has been provided regarding the net benefit of this tire technology. In this study, a comprehensive approach is used to compare new-generation wide-base tires (NG-WBT) with the dual-tire assembly (DTA). Numerical modeling, prediction methods, experimental measurements, and environmental impact assessment were combined to provide recommendations about the use of NG-WBT. A finite element approach, considering variables usually omitted in the conventional analysis of flexible pavement was utilized for modeling. Five hundred seventy-six cases combining layer thickness, material properties, tire load, tire inflation pressure, and pavement type (thick and thin) were analyzed to obtained critical pavement responses. A prediction tool, known as ICT-Wide, was developed based on artificial neural networks to obtain critical pavement responses in cases outside the finite element analysis matrix. The environmental impacts were determined using life cycle assessment. Based on the bottom-up fatigue cracking, permanent deformation, and international roughness index, the life cycle energy consumption, cost, and green-house gas (GHG) emissions were estimated. To make the outcome of this research effort useful for state departments of transportation and practitioners, a modification to AASHTOWare is proposed to account for NG-WBT. The revision is based on two adjustment factors, one accounting for the discrepancy between the AASHTOware approach and the finite element model of this study, and the other addressing the impact of NG-WBT.

Styles APA, Harvard, Vancouver, ISO, etc.

Amoroso, J. W., et J. C. Marra. Melt processed crystalline ceramic waste forms for advanced nuclear fuel cycles : CRP T21027 1813 : Processing technologies for high level waste, formulation of matrices and characterization of waste forms, Task 17208 : Final report. Office of Scientific and Technical Information (OSTI), août 2015. http://dx.doi.org/10.2172/1214167.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Nous offrons des réductions sur tous les plans premium pour les auteurs dont les œuvres sont incluses dans des sélections littéraires thématiques. Contactez-nous pour obtenir un code promo unique!