Bibliographies thématiques / Stabilite tension

Littérature scientifique sur le sujet « Stabilite tension »

Auteur : Grafiati
Publié le 4 mai 2024

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Articles de revues sur le sujet "Stabilite tension"

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Kuang, Jianxun, Guodong Chen, Zhoulong Yuan, Xiajun Qi, Qianhao Yu et Zhen Liu. « Dynamic Interactions of a Cable-Laying Vessel with a Submarine Cable during Its Landing Process ». Journal of Marine Science and Engineering 10, no 6 (3 juin 2022) : 774. http://dx.doi.org/10.3390/jmse10060774.

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The rapid development of offshore electricity grid construction has led to a great demand for submarine cable deployment. In this study, a numerical model is established based on the commercial software ANSYS-AQWA to investigate the dynamic interactions between a cable-laying vessel and a submarine cable during its landing process, which has not yet been reported and is critical to the safety of the cable. The numerical model was validated by an experimental test on the mooring stability of a vessel conducted in a wave tank. The effects of the cable length, the current velocity, the incident wave, and the wind direction on vessel stability and the tensions in the mooring lines and cable were investigated. When the cable length is short, the submarine cable acts as a mooring cable that can stabilize the hull, but it is not safe to apply force to the submarine cable. At the same time, an increase in the current speed also increases the tensile force of the submarine cable. The influence of different incident wave directions and wind directions on the stability and tension of ships in mooring lines and cables was studied, and the most unfavorable environmental conditions for submarine cable laying were determined under different environmental conditions.
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Liu, Peng, Yuanying Qiu, Yu Su et Jiantao Chang. « On the Minimum Cable Tensions for the Cable-Based Parallel Robots ». Journal of Applied Mathematics 2014 (2014) : 1–8. http://dx.doi.org/10.1155/2014/350492.

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This paper investigates the minimum cable tension distributions in the workspace for cable-based parallel robots to find out more information on the stability. First, the kinematic model of a cable-based parallel robot is derived based on the wrench matrix. Then, a noniterative polynomial-based optimization algorithm with the proper optimal objective function is presented based on the convex optimization theory, in which the minimum cable tension at any pose is determined. Additionally, three performance indices are proposed to show the distributions of the minimum cable tensions in a specified region of the workspace. An important thing is that the three performance indices can be used to evaluate the stability of the cable-based parallel robots. Furthermore, a new workspace, the Specified Minimum Cable Tension Workspace (SMCTW), is introduced, within which all the minimum tensions exceed a specified value, therefore meeting the specified stability requirement. Finally, a camera robot parallel driven by four cables for aerial panoramic photographing is selected to illustrate the distributions of the minimum cable tensions in the workspace and the relationship between the three performance indices and the stability.
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Liu, Peng, Haibo Tian et Xinzhou Qiao. « Minimum Cable Tensions and Tension Sensitivity for Long-Span Cable-Driven Camera Robots with Applications to Stability Analysis ». Actuators 12, no 1 (31 décembre 2022) : 17. http://dx.doi.org/10.3390/act12010017.

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Employing cables with strong flexibility and unidirectional restraints to operate a camera platform leads to stability issues for a camera robot with long-span cables considering the cable mass. Cable tensions, which are the constraints for the camera platform, have a critical influence on the stability of the robot. Consequently, this paper focuses on two special problems of minimum cable tension distributions (MCTDs) within the workspace and the cable tension sensitivity analysis (CTSA) for a camera robot by taking the cable mass into account, which can be used to investigate the stability of the robot. Firstly, three minimum cable tension distribution indices (MCTDIs) were proposed for the camera robot. An important matter is that the three proposed MCTDIs, which represent the weakest constraints for the camera platform, can be employed for investigating the stability of the robot. In addition, a specified minimum cable tension workspace (SMCTW) is introduced, where the minimum cable tension when the camera platform is located at arbitrary position meets the given requirement. Secondly, the CTSA model and cable tension sensitivity analysis index (CTSAI) for the camera robot were proposed with grey relational analysis method, in which the influence mechanism and influence degree of the positions of the camera platform relative to cable tensions was investigated in detail. Lastly, the reasonableness of the presented MCTDIs and the method for the CTSA with applications in the stability analysis of the camera robot were supported by performing some simulation studies.
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Shuaiquan, Zhao, Chang Yuping, Yang Yadie, Zhang Minglonghai, Hasan Kamrul et Hu Hong. « Auxetic behavior of warp knitted fabric under repeating tension ». Textile Research Journal 91, no 15-16 (25 janvier 2021) : 1732–41. http://dx.doi.org/10.1177/0040517521989277.

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In our previous study, a novel class of auxetic warp knitted fabrics were developed and their auxetic behaviors were studied under a single tensile test. However, during daily use, the fabrics are usually subjected to repeating tension rather than single tension. Therefore, the durability of the fabrics’ auxetic performance is of great importance. So far, the auxetic behavior of fabrics under repeating tension has not systematically been investigated. In this paper, we report a study on the auxetic behavior of warp knitted fabrics under repeating tension. All the fabric samples were subjected to a repeating tensile test within a tensile strain of 25% until 100 tensile cycles. The results show that the fabrics can keep their auxetic effect in both course and wale testing directions after 100 tensile cycles, and the auxetic effect in the wale direction is retained longer under higher tensile strains than that under lower tensile strains with the increase of tensile cycles. The results also indicate that auxetic stability in the course direction is much better than that in the wale direction. We hope that this study can offer useful information to improve the auxetic stability of auxetic fabrics for practical use.
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Igwe, Charles Arizechukwu, Hermansah, Martin Eze Obi et Toshiyuki Wakatsuki. « Using Selected Structural Indices to Pinpoint the Field Moisture Capacity of Some Coarse-Textured Agricultural Soils in Southeastern Nigeria ». Journal of Tropical Soils 16, no 2 (9 juillet 2013) : 151–59. http://dx.doi.org/10.5400/jts.2011.v16i2.151-159.

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Over- or underestimation of field capacity (FC) of agricultural soils could misguide soil and water management and this might have negative agronomic and environmental impacts. The study sought to identify the moisture tension for reliably estimating in the laboratory the FC of some sandy soils with low-activity clay minerals and at different levels of structure development in Nsukka agroecological zone in southeastern Nigeria. Fifty-four samples of topand subsoils under contrasting vegetation cover at three locations in the zone were analyzed for texture, organicmatter contents, bulk density and total porosity. Saturated hydraulic conductivities (Ksat) of the samples were equallydetermined. Water-conducting and water-filled porosities at each of 0.06-, 0.10- and 0.33-bar tensions were implied from water retention data at the respective tensions. The soils were categorized based on their levels of structure development using a structural stability index [(organic matter: silt+clay) %] as follows: very low (< 4%), low (4-7.5%) and moderate to high (> 7.5%) stability soils. Series of simple correlation tests were run among the waterconducting porosities at the various tensions and the Ksat of the soils. In each case, the soil was assumed to have attained FC at that moisture tension which the associated water-conducting porosity showed significant positive correlation with the Ksat. Our results revealed that the 0.06-bar tension overestimated the FC of the soils. The 0.10-bar tension, the commonly used moisture tension for the purpose in the study area, proved suitable only for soils within the moderate to high structural stability category. From all indications, the 0.33-bar tension best corresponded to the FC of the less structurally developed soils in the other two categories. The level of soil structure development should therefore be considered before deciding the suitable moisture tension for the determination of FC of these and similar soils in other tropical locations.Keywords: Coarse mineral soils, field moisture capacity, saturated hydraulic conductivity, structural stability,water-conducting pores
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REES, S. J., et M. P. JUNIPER. « The effect of surface tension on the stability of unconfined and confined planar jets and wakes ». Journal of Fluid Mechanics 633 (25 août 2009) : 71–97. http://dx.doi.org/10.1017/s0022112009007186.

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In this theoretical study, a linear spatio-temporal analysis is performed on unconfined and confined inviscid jet/wake flows with surface tension in order to determine convective/absolute instability criteria. There is a single mode that is due to surface tension and many modes that are due to the jet/wake column. In the unconfined case, the full impulse response is considered in the entire outer flow. On the one hand, the surface tension mode propagates slowly in the cross-stream direction but dominates at the front and back of the wavepacket. On the other hand, the jet/wake column modes propagate more quickly in the cross-stream direction and therefore define the boundaries of the central region of the wavepacket. The flow is particularly unstable when these modes interact. For unconfined flows, it is found that at low and intermediate surface tensions the flow can be more absolutely unstable than that without surface tension but at high surface tensions the flow is stabilized. The effect of confinement has previously been studied but not with the inclusion of surface tension. Confinement and surface tension combined cause the transition from convective to absolute instability to occur even with significant coflow. This effect is examined over an infinite domain of density ratios and confinement.
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Wei, Naying, Zhen Zhang, Xu Xu et Wenjuan Yao. « Stability Analysis of a TLP with Inclined Tension Legs under Different Marine Survival Conditions ». Journal of Marine Science and Engineering 10, no 8 (31 juillet 2022) : 1058. http://dx.doi.org/10.3390/jmse10081058.

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To verify that inclined tension legs can improve the stability of the tension leg platform, this paper established the dynamic equation of a tension leg platform (TLP) under marine environmental loads by using the modified Morrison equation considering the influence of ocean currents on wave forces. Additionally, the velocity and acceleration of random wave water particles were simulated via the JONSWAP spectrum. In addition, a three-dimensional model of a tension leg platform with inclined tension legs was established by AQWA, and its dynamic responses under variable survival conditions were compared and analyzed. The results showed that the surge and heave were more sensitive to the sea current, while the pitch was more sensitive to the wind. There is a significant difference in tendon tensions between the atypical TLP with inclined tension legs established in this study and the typical International Ship and Offshore Structures Committee (ISSC) TLP.
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Yakupov, R. G., et D. M. Zaripov. « Seismic stability of the underground main pipeline ». Proceedings of the Mavlyutov Institute of Mechanics 8, no 1 (2011) : 275–86. http://dx.doi.org/10.21662/uim2011.1.027.

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The stress-deformed state of the underground main pipeline under the action of seismic waves of an earthquake is considered. The generalized functions of seismic impulses are constructed. The pipeline motion equations are solved with used Laplace transformation by the time. Tensions and deformations of the pipeline have been determined. A numerical example is reviewed. Diagrams of change of the tension depending on earthquake force are provided in earthquake-points.
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Liu, Peng, Haibo Tian, Xiangang Cao, Xuhui Zhang, Xinzhou Qiao et Yu Su. « Dynamic Stability Measurement and Grey Relational Stability Sensitivity Analysis Methods for High-Speed Long-Span 4-1 Cable Robots ». Mathematics 10, no 24 (8 décembre 2022) : 4653. http://dx.doi.org/10.3390/math10244653.

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High-speed long-span 4-1 cable robots (4-1HSLSCRs) have the characteristics of a simple structure, superior performance and easy control, and they can be used comprehensively in coal quality sampling, water quality monitoring, aerial panoramic photographing, etc. However, because of the high-speed movement of the end-effector and the unidirectional constraint property and nonlinear characteristics of the long-span cables, the dynamic stability of the 4-1HSLSCRs presents severe challenges. This paper, as a result, focuses on the two special problems of carrying out dynamic stability measurement and a stability sensitivity analysis for the 4-1HSLSCRs. First, a systematic approach that combines the cable tension, position and velocity of the end-platform based on both the dynamic model and the determinations of the cable tension is proposed for the high-speed robot, in which two cable tension and two position influencing factors are developed, respectively, whereas a velocity function is constructed, which represents the influence of the end-effector velocity on the dynamic stability of the 4-1HSLSCRs. Second, a grey relational analysis method for analyzing the dynamic stability of the 4-1HSLSCRs is developed, where the relationship between the dynamic stability of the 4-1HSLSCRs and the influencing factors (the position and velocity of the end-effector, as well as the cable tension) is investigated in detail. Finally, the measure approach and sensitivity analysis method for dynamic stability of 4-1HSLSCRs, namely, a camera robot with a high speed and long-span cables, is verified through simulation results. The results show that the large-span cable sags have significant effects on both the cable tensions and the dynamic stability of the camera robot, whereas the stability sensitivity evaluation results indicate that the effect of the stability sensitivity of the cable tensions on the dynamic stability of the camera robot is the greatest, followed by the velocity of the end-effector, and last is the position of the end-effector.
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Howard, Anthony, Paul Harwood, Alice Benton, Charlotte Merrel, Peter Culmer, William Bolton et Todd Stewart. « AN IN VITRO STUDY EXAMINING WIRE TENSION IN FINE WIRE CIRCULAR EXTERNAL FIXATION CONSTRUCTS ». Orthopaedic Proceedings 106-B, SUPP_5 (23 avril 2024) : 27. http://dx.doi.org/10.1302/1358-992x.2024.5.027.

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IntroductionIlizarov fixators are reliant on tensioned fine wires for stability. The tension in the wires is generated using specific tensioning devices. Loss of wire tension over time may lead of loss a stability and complications. A series of in vitro experiments were undertaken to explore wire tensioner accuracy, the impact of fixation bolt torque and initial tension on loss of tension in ilizarov constructs under static and dynamic loads.Materials & MethodsMedical grade materials were applied to a synthetic bone analogue using surgical instruments in all experiments. Bolt torque was fixed at 6, 10 or 14 Nm using a torque limiting wrench. Wire tension was assessed using a strain measurement bridge. Wires were tensioned to 90, 110 and 130kg as measured by a commercial dynamometric tensioner. Static and dynamic testing was undertaken using an instron testing machine. Cyclical loads from 50–750N were applied for 5000 cycles.ResultsActual wire tension was approximately 15% less than indicated by the tensioner device. Using fixation bolt torques of 10Nm and 14Nm achieved final wire tensions of around 60% and 80% of that applied at 90 and 130kg of applied tension. Static load testing demonstrated self stiffening to similar levels in all pre-tensions. Dynamic testing demonstrated significant loss of tension, most of which occured in the first 3 cycles, inversely proportional to the tension initially applied.ConclusionsThese experiments provides insight into the effect of initially applied wire tension on Illizarov mechanical performance. It is important surgeons understand how the different ways that these devices are applied affects mechanical performance. Further research examining what factors affect performance across different manufacturers equipment would therefore be relevant, alongside the development of novel fixation methods to reduce wire slippage and the further development of equipment for clinical use.
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Thèses sur le sujet "Stabilite tension"

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Holtzscherer, Christine. « Polymerisation de l'acrylamide en microemulsion inverse : influence des electrolytes sur la stabilite des latex obtenus ». Université Louis Pasteur (Strasbourg) (1971-2008), 1986. http://www.theses.fr/1986STR13324.

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Preparation de polymeres de masse moleculaire elevee, encapsules dans des microgouttelettes d'eau dispersees dans l'huile, de faible viscosite et stabilite elevee. Effets de "saltingin" et de "salting out" (acetate de sodium)
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REYNAUD, JEROME. « Stabilite de structures metal isolant semi-conducteur a base de silicium amorphe et silicium polycristallin sous l'effet de contraintes en tension d'apres des mesures de capacite ». Paris 6, 1996. http://www.theses.fr/1996PA066356.

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Cette etude porte sur des structures metal/isolant/semi-conducteur (mis) a base de silicium amorphe et de silicium polycristallin en relation avec l'application aux ecrans plats a cristaux liquides des transistors a effet de champ en couches minces (tft). L'analyse theorique des mesures de capacite quasi-statique et quasi-stationnaire met l'accent sur la prise en compte d'un continuum d'etats localises dans le volume du semi-conducteur amorphe. Pour le silicium polycristallin, nous avons compare deux methodes d'hydrogenation: l'hydrogenation au moyen d'une couche de nitrure de silicium hydrogenee et l'hydrogenation par un plasma micro-onde. L'hydrogenation par nitruration ameliore la densite d'etats par rapport a la structure non hydrogenee. Cependant, la densite reste elevee et des post-recuits a basse temperature ne conduisent pas a une amelioration importante. L'hydrogenation par plasma micro-onde donne une densite d'etats plus faible. Les resultats tires de mesures de capacite de structures mis et des caracteristiques courant-tension i#d(v#g) des tft presentent la meme evolution en fonction de recuits successifs de 200c a 450c. Sur les structures a base de silicium amorphe, nous avons etudie l'effet de contraintes en tension a differentes temperatures. A temperature ambiante, seules les contraintes positives ont un effet sur les diodes mis. Les memes lois regissent l'evolution temporelle des tensions caracteristiques des transistors et des structures mis sous l'effet de contraintes de duree variable realisees a 100c. Avec des contraintes a 200c, les resultats tires des mesures de capacite quasi-statique montrent que les contraintes induisent une modification de la densite des defauts electriquement actifs dans le semi-conducteur. Finalement, seules les structures a base de silicium polycristallin hydrogene par plasma micro-onde presentent une densite d'etats d'interface comparable a la densite d'etats ramenee a l'interface des structures a base de silicium amorphe
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Hardiyatmo, Hary Christady. « Approche expérimentale du dimensionnement des massifs renforcés à parement cellulaire ». Université Joseph Fourier (Grenoble), 1995. http://www.theses.fr/1995GRE10092.

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Les murs cellulaires associes a un massif de sol renforce par geosynthetiques constituent une technique tres utilisee en france depuis dix ans. Ce concept est interessant techniquement et esthetiquement. Nous presentons l'etude de comportement des massifs renforces par geosynthetiques associes a un parement cellulaire, a partir d'un modele analogique plan de schneebeli. Ce modele nous a permis de montrer l'influence d'un certain nombre parametres constructifs. Nous presentons une etude parametrique concernant l'evolution des contraintes horizontales sur le mur cellulaire, les contraintes verticales a la base de l'ouvrage ainsi que la tension des armatures aux points d'attache. On montre: les effets de l'espacement entre les nappes, de la longueur des armatures, de leur raideur, ainsi que l'effet de la liaison des armatures aux cellules du parement, de la coupure des armatures. De meme, l'etude parametrique concernant la mesure des contraintes horizontales sur le mur cellulaire engendrees par une charge en tete a permis de montrer l'influence du renforcement sur la repartition de ces contraintes le long du parement cellulaire. Finalement, nous presentons l'etude cinematique du comportement a la rupture des massifs renforces avec ou sans surcharge en tete et les calculs de stabilite associes, en proposant une methode d'etude independante, de l'equilibre du mur cellulaire et du massif en sol renforce a l'arriere de ce parement
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Praing, Chulasa. « Stabilité d'un réseau de transport avec pôles de production et de consommation éloignés en période de forte croissance ». Phd thesis, Grenoble INPG, 2000. http://www.theses.fr/2000INPG0106.

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Aujourd'hui, l'exploitation des grands réseaux électriques est de plus en plus complexe du fait de l'augmentation de leur taille. De la présence de lignes d'interconnexion de grande longueur, de l'adoption de nouvelles techniques, de contraintes économiques, politiques et écologiques. Ces facteurs obligent les opérateurs à exploiter ces réseaux près de la limite de stabilité et de sécurité. Les situations de pays à forte croissance de consommation accroissent encore les risques d'apparition du phénomène d'instabilité. Pour éviter ce phénomène, l'étude de stabilité (de tension et des angles) est proposée dans cette thèse. Cette étude est un outil très important pour déterminer la possibilité de transfert de puissance dans le contexte de dérégulation future. Le travail de cette thèse est mené grâce à l'utilisation des techniques d'analyse statique et de simulation dynamique avec les logiciels Matlab et Eurostag. Ces techniques sont appliquées principalement au cas du grand réseau (220 et 500 kV) du Vietnam, du réseau test 500 kV BPA aux Etats Unis et à celui du Massif Central français. Dans ce travail, plusieurs techniques d'analyse statique sont présentées de façon à estimer la marge de stabilité et à identifier les lieux critiques pour la stabilité de tension. Les résultats obtenus sont conformes à l'exploitation réelle du réseau du Vietnam. Puis, la simulation dynamique permet d'étudier tous les comportements du réseau de manière plus détaillée pour n'importe quel régime de fonctionnement. Grâce à ces simulations, la réponse de chaque variable des éléments du réseau est observée; les résultats entre les mesures et les simulations sont comparés ; les composants les plus sensibles à la stabilité de tension sont identifiés ainsi que les origines de l'instabilité (de tension ou des angles). Enfin, la combinaison entre l'analyse statique et la simulation dynamique est réalisée pour tirer avantage des deux analyses. Dans certaines conditions critiques, le réseau électrique peut connaître un phénomène d'instabilité. Ce phénomène peut être évité grâce à l'application de mesures préventives et correctrices. Dans cette thèse, trois méthodes de mesures préventives sont présentées : deux méthodes classiques et une nouvelle méthode. Elles servent à diminuer les risques d'instabilité de tension en régime permanent avant ou après une perturbation en utilisant les techniques de l'optimisation du calcul de répartition de puissance. Une nouvelle méthode de mesure correctrice est également présentée dans cette thèse, elle sert à éviter l'instabilité de tension en utilisant la sensibilité des puissances active et réactive avec la tension. Les nœuds critiques, où la charge doit être délestée, sont déterminés par les analyses statiques. Enfin, les solutions, pour améliorer la stabilité (de tension et des angles) et pour éviter l'instabilité, sont données en utilisant des dispositifs de réglage modernes (FACÎS, compensateur de charge, PSS)
Today's opération of large povver Systems is continuously increasing in complexity due to size growth, to high ievel of interconnections, to the use of new techniques, and to economical, political and ecological constraints. Thèse factors lead the operators to operate thèse Systems close to their limit of stability and security. The risk of instability is increasing in case of a strongïy growing power consumption. To avoid this phenomenon, the study of stability (voltage and rotor angle) is proposed in this thesis. This study is a very signtficant mean to détermine available transfer capability (ATC) in deregulated envïronment. The work of this thesis has been conducted vvith the use of the static analysis techniques and dynamic simulation vvith Matlab and Eurostag software. Thèse techniques are applied mainly in the Vietnam povver System {220 and 500 kV), the BPA test System 500 kV in USA and the Massif Central power System in France. In this work, several static analysis techniques are presented in order to estimate the stability margin and to identify the entical areas for the voltage stability. The results obtained are in conformity with the real exploitation of Vietnam povver system. Then, dynamic simulation allows studying ail the behaviors of the system for any opérations. With thèse simulations, the response of each variable of the éléments of the system is observed; the results of measurements and simulations are compared: the components most sensitive to the voltage stability are identified as well as the origins of instability (voltage or rotor angle). In the end, the eombination between the static analysis and dynamic simulation are carried out in order to take advantage from the two analyses. Under certain critical conditions, the povver system can be affected by a phenomenon of instability. This phenomenon can be avoided by applying préventive and corrective measures. In this thesis, three methods of préventive measures are presented: two classical methods and a new method. They are used to decrease the risks of voltage instability in the steady state before or after a disturbance, by using the optimal power flow techniques (OPF). A new method of corrective measure is also presented in this thesis, it is used to avoid the voltage instability by using the sensitivity of the active and reactive power to the voltage. The critical nodes, where the load must be shed, are determined by the static analysis. In the end, several solutions, to improve stability (voltage and rotor angle) and to avoid instability. Are given by using modem reguîatory devices (FACTS, load compensation, PSS)
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Hasic, Anida. « La tensione tra interiore ed esteriore. Studio attorno all'idea di securitas in Seneca ». Thesis, Paris 4, 2016. http://www.theses.fr/2016PA040079.

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Ce travail de recherche reconstruit la valeur de la notion de securitas d'un point de vue conceptuel et du point de vue de l'histoire de la philosophie dans le but de montrer la centralité du concept et la cohérence de son développement dans la réflexion philosophique de Sénèque. À cette fin les dimensions intérieure et extérieure sont examinées dans leur relation d'implication mutuelle : premièrement la securitas est étudiée par rapport à la dimension psychologique du sujet dans le contexte du progrès moral, deuxièmement, elle est étudiée par rapport à la relation à autrui dans le contexte sociale de l'Empire. La securitas est également analysée en référence au statut épistémologique des Naturales Quaestiones pour étudier la relation que l'homme entretient avec le monde des phénomènes naturels grâce à la science. En outre le concept a été examiné à l’intérieur de la relation entre oeuvre philosophique et oeuvre tragique (Oedipus). Le postulat éthique de la securitas trouve une résonance et un sens complémentaires dans la poétique de l’oeuvre tragique, ce qui détermine donc une poétique de l'incertain. La recherche montre que la présence du focus sur la dimension intérieure vise des objectifs éthiques concernant la sphère extérieure. Ce qui ressort en outre de l’étude de la notion de securitas est une relation tendue avec le monde. Ce caractère tendu de la relation au monde nous a conduit à clarifier la position de Sénèque vis-à-vis de la tradition stoïcienne à laquelle il appartient, ainsi que son attitude par rapport aux autres influences philosophiques (Lucrèce, Cicéron, Celse) et idéologiques (Velleius Paterculus) auxquelles il est perméable
This research reconstructs the value of the concept of securitas in Seneca's thought with the aim to show its centrality and the organic nature of its development both from a conceptual point of view and from the point of view of the history of ideas. Therefore the interior and the exterior dimensions of the notion and their mutual implications are analyzed: securitas is examined in its interior psychological dimension in the context of moral progress, subsequently the importance of the concept is taken into account in connection with social relations in the imperial context. The epistemological questions of the notion in Naturales Quaestiones are also studied in order to investigate the relationship that man entertains with the world of natural phenomena through science. Securitas was also examined within the relationship between philosophical and dramatic works (Oedipus), suggesting the presence of ethical assumptions of securitas in their inverted sense on a poetic level and allowing us to describe Seneca's poetic as a poetic of uncertainty. The research shows that the ethical aspects which focus on the interior dimension become part of relating to the outside world as well. The tense relationship with the world, which emerges from the study of the concept of securitas, can also be linked to the way Seneca deals with previous philosophical tradition and have contributed to clarify his position with respect to the Stoic tradition to which he belongs, as well as with respect to other philosophical (Lucretius, Cicero, Celsus) and ideological (Velleius Paterculus) influences which are present in his works
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Rios, Mario Alberto. « Modélisation pour analyses dynamiques des réseaux électriques avec compensateurs de puissance réactive-SVC ». Grenoble INPG, 1998. http://www.theses.fr/1998INPG0099.

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Cette Thèse traite de la modélisation des réseaux électriques comportant des compensateurs statiques de puissance réactive (SVC). La modélisation est basée sur des modèles d'ordre réduit utilisant la réduction par troncature des valeurs singulières de Hankel et l'identification dynamique N4Sid. Pour le cas de réseaux comportant plusieurs SVC ou composants FACTS (Flexible AC Transmission Systems), on a proposé une structure de modélisation par sous-systèmes calculée par des techniques d'ordre réduit. Ces modèles réduits permettent de calculer des lois de commande type LQG (Linear Quadratic Gaussian Regulator) et des commandes robustes d'ordre réduit qui ont des performances supérieures par rapport aux correcteurs traditionnels des SVC (commande proportionnelle). Avec la structure en sous-systèmes, on a proposé des méthodes de calcul des correcteurs décentralisés appliqués aux réseaux électriques. D'autre part, on a proposé une technique d'analyse de la robustesse des réseaux en utilisant la théorie d'analyse des valeurs singulières structurées, permettant de déterminer les frontières de stabilité basées en le calcul des fonctions de transfert de l'ensemble système-commande. Les différentes techniques développées dans le cadre de cette thèse sont appliquées à un réseau test de 11 nœuds et à un grand réseau électrique et donnent des résultats très satisfaisants
This thesis studies the modeling and analysis of power System containing static VAR compensators (SVC). Low-order models, calculated by Hankel singular-value truncation réduction and N4Sid dynamic identification, provide the foundation for the modeling and analysis techniques. For cases where many SVCs or FACTS (Flexible AC Transmission Systems) devices are installed in a power System, a new subsystem structure based on thèse low-order modeling techniques has been developed. The proposed low-order models allow the computation of low-order LQG-type (Linear Quadratic Gaussian Regulator) control laws, as well as low-order robust controls, which provide a better performance relative to traditional SVC controls (proportional type). Using the subsystem structure formulated in this thesis, methods for calculating decentralized controllers for power Systems hâve been conceived. In addition, through the use of structured singular values, a new robustness analysis technique has been developed which allows the détermination of stability boundaries through the calculation of closed-loop transfer functions. The theoretical approaches in this work hâve been applied to a test power system containing 11 nodes, as well as a larger 173-node test system
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Haywood, Kieran. « The dynamic surface properties and foam stability of protein solutions ». Thesis, University of Reading, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.252241.

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Cosson, Marjorie. « Stabilité du réseau électrique de distribution. Analyse du point de vue automatique d'un système complexe ». Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLC065/document.

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Pour maintenir la tension dans des bornes admissibles, des régulations locales de puissance réactive (Q) en fonction de la tension (U) sont envisagées sur les réseaux de distribution. Ces travaux étudient l’impact de ces régulations sur la stabilité des réseaux de distribution accueillant de la production. Une étude empirique confirme le risque d’instabilité de la tension et souligne le lien avec les paramètres de la régulation. Pour aider les gestionnaires à les choisir, trois méthodes d’étude de la stabilité sont proposées. Tout d’abord, une méthode formelle fondée sur les notions d’abstraction discrète et de bisimulation est développée. Elle offre une grande précision au prix d’un effort de calcul important. Pour contournercette difficulté, un critère analytique portant sur le temps de réponse des régulations Q(U) est formulé. Ensuite, un critère valable dans tous les cas est proposé pour les codes de réseaux. Enfin, l’extension desméthodes à des cas plus complexes est discutée
To maintain the voltage within specified limits, local control laws of distributed generators (DGs) reactive power (Q) with respect to their voltage (U) have been considered. This work studies the impact of Q(U) control laws on distribution feeders’voltage stability. An empirical study confirms the risk of voltage instability and highlights its dependence on control law parameters. To help distribution grid operators to choose these parameters, three methods assessing stability are formulated.First, a formal method based on discrete abstraction and bisimulation calculation is developed. The proposed approach yields precise results but with a high computational load. Then, to overcome this issue, an analytical criterion adapting Q(U) control laws response time with respect to grid parameters is formulated. Finally, a general criterion, valid in any cases, is established in order to be included in the grid codes. To conclude this work, extension to more complex cases is discussed
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El, Kerri Nabil. « Etude par tensiométrie dynamique de la stabilité d'interfaces modèles asphalténées ». Pau, 2003. http://www.theses.fr/2003PAUU3019.

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L'industrie pétrolière est souvent confrontée à des émulsions eau/pétrole extrêmement stables qu'elle doit rompre pour éviter des surcoûts très élevés dans la chaîne de production, ou réduire les pollutions environnementales lors de déversements accidentels en mer. La stabilité de ces systèmes peut en grande partie être attribuée aux propriétés tensioactives des molécules d'asphaltènes présentes dans le pétrole brut. L'objectif de ce travail était de tenter de préciser les mécanismes d'action de ces molécules, et ceux d'additifs habituellement utilisés pour séparer l'eau et le pétrole, en mettant en œuvre la tensiométrie dynamique. Nous avons commencé par extraire des molécules d'asphaltènes du pétrole brut par addition de pentane. Nous avons ensuite dissous ces molécules dans du cyclohexane pour fabriquer des émulsions modèles eau/cyclohexane asphalténé dont nous avons vérifié, par la méthode des bottle-tests , que la stabilité est tout à fait comparable à celle des émulsions eau/pétrole. Ainsi nous avons validé l'utilisation d'interfaces modèles eau/cyclohexane asphalténé pour la suite de notre travail. En utilisant le tensiomètre à goutte Tracker commercialisé par la Société I. T. Concept, nous avons trouvé que la relaxation de l'interface modèle eau/cyclohexane asphalténé présente une large distribution de temps de relaxations. Les temps les plus courts correspondent à la migration des asphaltènes de petite taille vers l'interface; les temps les plus longs traduisent l'association des asphaltènes adsorbés à l'interface. Les mesures de rhéologie interfaciale confirment que, au cours du temps, les molécules d'asphaltène forment des agrégats bidimensionnels de plus en plus liés. Nous avons étendu le domaine d'étude à une plus grande gamme de pulsations grâce au principe d'équivalence temps-température. Cette extension nous a permis de montrer que dans l'intervalle de températures 20 ʿC - 55 ʿC (pulsations faibles) l'interface modèle eau/cyclohexane asphalténé est recouverte par un gel d'asphaltènes au voisinage de son point de gel. Au dessous de 20ʿC (pulsations élevées) nous avons trouvé que ce gel subit une transition vitreuse responsable de l'observation des poches solides qui apparaissent au dégonflement des gouttes dans cette gamme de températures. Ainsi la grande stabilité de l'émulsion eau/cyclohexane asphalténé est due à la présence d'un gel d'asphaltènes à la surface des gouttelettes, ce qui empêche leur coalescence. La méthode des bottle-tests montre que les sels ne sont pas des désémulsifiants. Sans doute parce que l'agrégation des asphaltènes responsable de la formation du gel stabilisateur ne se fait pas sous l'action de forces électrostatiques mais plutôt sous l'action de forces hydrophobes. Cette hypothèse est corroborée par le comportement rhéologique de l'interface qui, en présence de sel, conserve toutes les caractéristiques de l'interface asphalténée en milieu non salé et par conséquent reste recouverte par le gel. La méthode des bottle-tests montre également que le dodécylsulfate de sodium n'est pas un désémulsifiant alors que les tensioactifs PE 6800 et PE 6200 de la famille des Pluronic le sont. L'étude rhéologique des interfaces eau/cyclohexane asphalténé révèle que, en présence du dodécylsulfate de sodium, l'interface conserve toutes les caractéristiques de l'interface asphalténée, alors qu'en présence du PE 6800 ou du PE 6200, l'interface présente les propriétés viscoélastiques d'une interface non asphalténée, respectivement recouverte par le PE 6800 ou le PE 6200. Un bon désémulsifiant est donc un tensioactif qui est capable de détruire le gel stabilisateur. Ainsi la rupture de l'émulsion eau/cyclohexane asphalténé par le PE 6200 ou le PE 6800 est due à la disparition du gel d'asphaltène à la surface des gouttelettes, ce qui autorise leur coalescence.
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Hasic, Anida. « La tensione tra interiore ed esteriore. Studio attorno all'idea di securitas in Seneca ». Doctoral thesis, Università degli studi di Padova, 2016. http://hdl.handle.net/11577/3427135.

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This research reconstructs the value of the concept of securitas in Seneca's thought with the aim to show its centrality and the organic nature of its development both from a conceptual point of view and from the point of view of the history of ideas. Therefore the interior and the exterior dimensions of the notion and their mutual implications are analyzed: securitas is examined in its interior psychological dimension in the context of moral progress, subsequently the importance of the concept is taken into account in connection with social relations in the imperial context. The epistemological questions of the notion in Naturales Quaestiones are also studied in order to investigate the relationship that man entertains with the world of natural phenomena through science. Furthermore securitas was examined within the relationship between philosophical and dramatic works (especially Oedipus), suggesting the presence of ethical assumptions of securitas in their inverted sense on a poetic level and allowing us to describe Seneca's poetic as a poetic of uncertainty. Contrary to the most common interpretation of senecan ethics as focused on the withdraw into one's self, the research shows that the ethical aspects which focus on the interior dimension become part of relating to the outside world as well. The tense relationship with the world, which emerges from the study of the concept of securitas, can also be linked to the way Seneca deals with previous philosophical tradition and have contributed to clarify his position with respect to the Stoic tradition to which he belongs, as well as with respect to other philosophical (Lucretius, Cicero, Celsus) and ideological (Velleius Paterculus) influences which are present in his works.
La presente ricerca ricostruisce dal punto di vista storico-filosofico e concettuale il valore della nozione di securitas in Seneca con l'obiettivo di mostrare la centralità del concetto e l'organicità del suo svolgimento nell'ambito della riflessione filosofica del pensatore Romano. Vengono pertanto esaminate le dimensioni interiore ed esteriore della nozione nella loro relazione di reciproca implicazione: da un lato la securitas viene studiata con riferimento alla dimensione psicologica interiore del soggetto nel contesto del progresso morale, dall'altro, se ne prendono in considerazione gli effetti quanto alla dimensione dei rapporti sociali nel contesto imperiale. La nozione di securitas è analizzata anche con riferimento allo statuto epistemologico delle Naturales Quaestiones per indagare il rapporto che l'uomo intrattiene col mondo dei fenomeni naturali attraverso la scienza. Si è inoltre esaminato il concetto all'interno della relazione tra opera filosofica e opera tragica (in particolare l'Oedipus), suggerendo la presenza degli assunti etici della securitas a livello poetico nel loro senso rovesciato e determinanti perciò una poetica dell'incertezza. Contrariamente all'interpretazione più ricorrente secondo cui la riflessione etica senecana sarebbe focalizzata sul ripiego su se stessi, la ricerca mostra come gli aspetti etici che si concentrano sulla dimensione interiore, siano in realtà finalizzati alla sfera esteriore. La relazione tensiva col mondo, che emerge dallo studio della nozione di securitas, risente anche del rapporto di Seneca alla tradizione filosofica precedente e ha permesso di chiarire la sua posizione rispetto alla tradizione stoica cui appartiene, nonché rispetto alle influenze filosofiche (Lucrezio, Cicerone, Celso) e ideologiche (Velleio Patercolo) cui è permeabile.
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Livres sur le sujet "Stabilite tension"

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Aharon, I. Hydrodynamic stability of multicomponent droplet gasification in reduced gravity. [Washington, DC : National Aeronautics and Space Administration, 1995.

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Aharon, I. Hydrodynamic stability of multicomponent droplet gasification in reduced gravity. [Washington, DC : National Aeronautics and Space Administration, 1995.

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W, McConley Marc, et United States. National Aeronautics and Space Administration., dir. Stability of thin liquid sheet flows. [Washington, DC : National Aeronautics and Space Administration, 1997.

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Group, International Crisis. Uganda : No resolution to growing tensions. Nairobi] : International Crisis Group, 2012.

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Colinet, P. Nonlinear dynamics of surface-tension-driven instabilities. Berlin : Wiley-VCH, 2001.

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Till, Geoffrey, dir. The Changing Maritime Scene in Asia : Rising Tensions and Future Strategic Stability. London : Palgrave Macmillan UK, 2015. http://dx.doi.org/10.1057/9781137506320.

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Andy, Resnik, Kaukler William F et United States. National Aeronautics and Space Administration., dir. Stability limits and dynamics of nonaxisymmetric liquid bridges : First annual report ... Huntsville, Ala : Center for Microgravity and Materials Research, University of Alabama in Huntsville, 1993.

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Anita, Garg, Hull David R, United States. National Aeronautics and Space Administration. et U.S. Army Research Laboratory., dir. Microstructural and strength stability of a developmental CVD SiC fiber. [Washington, D.C.] : National Aeronautics and Space Administration, 1995.

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Anita, Garg, Hull David R, United States. National Aeronautics and Space Administration. et U.S. Army Research Laboratory., dir. Microstructural and strength stability of a developmental CVD SiC fiber. [Washington, D.C.] : National Aeronautics and Space Administration, 1995.

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E, McCaughan Frances, et United States. National Aeronautics and Space Administration., dir. Coupled Marangoni-Benard/Rayleigh-Benard instability with temperature dependent viscosity. [Washington, DC] : National Aeronautics and Space Administration, 1994.

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Chapitres de livres sur le sujet "Stabilite tension"

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Straughan, Brian. « Surface Tension Driven Convection ». Dans The Energy Method, Stability, and Nonlinear Convection, 132–44. New York, NY : Springer New York, 1992. http://dx.doi.org/10.1007/978-1-4757-2194-2_8.

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Straughan, Brian. « Surface tension driven convection ». Dans The Energy Method, Stability, and Nonlinear Convection, 161–79. New York, NY : Springer New York, 2004. http://dx.doi.org/10.1007/978-0-387-21740-6_8.

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Toshev, Borislav V. « Metastability and Lability in Surface Phase Transitions : Surface Forces and Line Tension Effects ». Dans Colloid Stability, 335–52. Weinheim, Germany : Wiley-VCH Verlag GmbH & Co. KGaA, 2011. http://dx.doi.org/10.1002/9783527631070.ch13.

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Toshev, Borislav V. « Metastability and Lability in Surface Phase Transitions : Surface Forces and Line Tension Effects ». Dans Colloid Stability, 335–52. Weinheim, Germany : Wiley-VCH Verlag GmbH & Co. KGaA, 2014. http://dx.doi.org/10.1002/9783527631193.ch13.

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Speedy, Robin J. « Limits of Stability for Liquids Under Tension ». Dans Liquids Under Negative Pressure, 1–12. Dordrecht : Springer Netherlands, 2002. http://dx.doi.org/10.1007/978-94-010-0498-5_1.

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Scolaro, S., C. Totaro, D. Presti, Sebastiano D’Amico, G. Neri et B. Orecchio. « Estimating Stability and Resolution of Waveform Inversion Focal Mechanisms ». Dans Moment Tensor Solutions, 93–109. Cham : Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-77359-9_5.

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Tvergaard, V. « Tensile Instabilities at Large Strains ». Dans Bifurcation and Stability of Dissipative Systems, 251–91. Vienna : Springer Vienna, 1993. http://dx.doi.org/10.1007/978-3-7091-2712-4_6.

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Zhang, Yingbin. « Seismic Slope Stability Analysis by Considering Tension Crack ». Dans Springer Natural Hazards, 41–62. Singapore : Springer Singapore, 2017. http://dx.doi.org/10.1007/978-981-10-2935-6_3.

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Campbell, I. C. « Rock of Ages : Tension Underlying Stability in Tonga ». Dans The GeoJournal Library, 273–88. Dordrecht : Springer Netherlands, 2006. http://dx.doi.org/10.1007/1-4020-3826-7_16.

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Fuhrmann, Paul A., et Uwe Helmke. « Tensor Products, Bezoutians, and Stability ». Dans The Mathematics of Networks of Linear Systems, 209–79. Cham : Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-16646-9_5.

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Actes de conférences sur le sujet "Stabilite tension"

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Gallagher, Conor, Dara Williams et Donogh Lang. « Modelling of Marine Riser Tensioner Load Variations and Implications for Minimum Top Tension Settings in Drilling Risers ». Dans ASME 2012 31st International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/omae2012-83753.

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As the pace of deepwater oil and gas exploration continues to grow, so too does demand for modern drilling vessels with equipment capable of operating in water depths of 10,000ft or greater. These greater water depths place significant demands on the drilling riser and the riser tensioning system. Modern riser tensioners are complex hydro-pneumatic systems and far from applying a constant top tension, the stiffness and damping characteristics associated with the tensioner mean that the applied tension can vary substantially as the tensioner strokes in response to vessel heave. As a result it is critical that the riser tensioner system response be captured in sufficient detail when evaluating the loads on the drilling riser. Riser tensioner systems for deepwater drilling must be capable of supplying the required tension to satisfy the minimum stability tension requirement, as per API RP 16Q; however this recommended practice does not adequately account for dynamic tensioner load variation, which can be up to 50% of the nominal tension. For deepwater drilling riser systems, where riser load limits are being approached, accurate modeling of the tensioner system load variation is required to ensure that the riser does not experience compression or excessive stresses. Furthermore, as the dynamic tension variations are largely velocity dependent, they can be relatively independent of water depth. Thus larger percentage variations in tension are experienced at low tensions when compared to higher tensions. This is an important consideration when calculating minimum top tensions for deepwater drilling rigs in shallower water depths. This paper presents a comparison of the response of a direct-acting riser tensioner (DAT) system for a range of environments. The comparison is based on results from detailed tensioner models that include the individual hydraulic and pneumatic components of the tensioner system and that are fully integrated with a non-linear 3D structural FE analysis tool [1]. The FE model is based on a widely-validated-non-linear software tool [3]. The detailed tensioner model has been validated against manufacturer performance data for existing in-service tensioner systems. The detailed tensioner model has also been used as part of a drilling riser recoil analysis study [1] which provided a good comparison of recoil analysis results against a published recoil test case. The impact on the global riser response of accurately modeling the tensioner system behavior is demonstrated, while the implications for the calculation of minimum top tension are also discussed.
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Teman, Adam. « Dynamic stability and noise margins of SRAM arrays in nanoscaled technologies ». Dans 2014 IEEE Faible Tension Faible Consommation (FTFC). IEEE, 2014. http://dx.doi.org/10.1109/ftfc.2014.6828617.

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Bidkar, Rahul A., Arvind Raman et Anil K. Bajaj. « Aeroelastic Stability of Wide Webs and Narrow Ribbons ». Dans ASME 2007 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/detc2007-35169.

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Uni-axially tensioned wide webs and narrow ribbons commonly used in the paper-handling, textile, sheet-metal, and plastics industries are known to undergo large amplitude vibrations characterized as aeroelastic flutter. The aeroelastic stability of stationary wide webs and narrow ribbons coupled with fluid flow across the free edges of the web or ribbon is investigated in this article. The web or ribbon is modeled as a uni-axially tensioned Kirchhoff plate with vanishingly small bending stiffness. The 3D unsteady fluid flow surrounding the web or ribbon is evaluated numerically by using the vortex-lattice method. Wide webs are mainly found to exhibit the divergence instability. For some values of the applied tension, the clustered web modes exhibit frequency curve veering accompanied by a weak flutter instability before the occurrence of the divergence instability. The applied tension plays a critical role in deciding the type of instability in narrow ribbons. In cross flow, depending on the applied tension, narrow ribbons undergo flutter instability or divergence instability or the simultaneous onset of both instabilities.
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Brown, Darren, et Jim Glancey. « Stability and Fatigue Analysis of Long-Span Continuous Band Saw Blades ». Dans ASME 2006 International Mechanical Engineering Congress and Exposition. ASMEDC, 2006. http://dx.doi.org/10.1115/imece2006-14402.

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Long span, unsupported, continuous steel band saw blades are commonly used for cutting in a number of industries worldwide. A model of the stresses generated in the blade under several loading scenarios are developed and used to evaluate the potential for fatigue failure with different support pulley and blade designs. Torsional blade stability is modeled and used to determine the critical in-plane cutting force above which the blade will twist. The effects of blade thickness and tension on stability are examined. Results indicate that stability can be improved with increasing thickness and tension at the expense of fatigue life. For spans greater than 1.5m, blade tensions required for stability are not practical, and suggest that a blade guide is necessary to achieve required cutting forces.
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Todd, William. « Stability and Frequency Response of Top-Tensioned Risers and SCR’s : The L/D Ratio in Perspective ». Dans ASME 2009 28th International Conference on Ocean, Offshore and Arctic Engineering. ASMEDC, 2009. http://dx.doi.org/10.1115/omae2009-79549.

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Stability is closely linked to the dynamic behavior of risers and SCR’s. This paper reviews the L/D criterion as used to categorize offshore structural elements and places this criterion in perspective when used in VIV calculations to compare slender beams, beam-columns and cable behavior to anticipated results for top-tensioned risers with like L/D ratios. The stability of beam-columns with various end conditions and loadings are compared to that of an in-service 2400m top-tensioned riser. An analytic solution for the frequencies and mode shapes of top-tensioned risers at varying top-tension is given and factors which influence the dynamic behavior detailed. The analysis demonstrates that loads and representation of the load distribution are vital to obtaining valid results. Close-coupling of displacement and slope with loading are essential to the analysis. Results are shown of the effects of varying top-tension factor (TTF) on the stability and dynamic response of risers and SCR’s.
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Roe, Philip, et Keiichi Kitamura. « Artificial Surface Tension to Stabilize Captured Shockwaves ». Dans 38th Fluid Dynamics Conference and Exhibit. Reston, Virigina : American Institute of Aeronautics and Astronautics, 2008. http://dx.doi.org/10.2514/6.2008-3991.

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Lu, Jun, Gary Arnold Pope et Upali Peter Weerasooriya. « Stability Investigation in Low-Tension Surfactant Floods ». Dans SPE International Symposium on Oilfield Chemistry. Society of Petroleum Engineers, 2013. http://dx.doi.org/10.2118/164090-ms.

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Xu, Ning, et Jun Zhang. « Pitch/Roll Static Stability of Tension Leg Platforms ». Dans ASME 2010 29th International Conference on Ocean, Offshore and Arctic Engineering. ASMEDC, 2010. http://dx.doi.org/10.1115/omae2010-20625.

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Severe hurricanes in recent years have raised concerns about the safety and the robustness of the Tension Leg Platform (TLP) concept in the deep water Gulf of Mexico. This study investigates the static stability of different types of TLPs representing those deployed in the Gulf of Mexico, under three different scenarios. That is, a TLP with an intact tendon system, a partially damaged tendon system, and a completely damaged tendon system. The two types of TLP chosen for this study are the conventional four-leg TLP (C-TLP) and the Mono-column TLP. To avoid buckling and yielding occurring in a tendon, the maximum righting moment provided by an intact or partially damaged tendon system is reached when the tension in one or more tendons on the down tension leg becomes zero or when the tension in one or more tendons on the up tension leg reach the yielding strength. This definition leads us to identify the most sensitive directions of met-ocean conditions to a TLP with an intact or partially damaged tendon system. Hence, our finding may also be used in the study on the dynamic simulations of a TLP. The righting moments of each TLP in the three different scenarios are respectively computed and compared with related wind-induce static upsetting moment at certain velocities. By comparing their ratios, the static stability of a TLP and the redundancy of its tendon system may be revealed, which has important implication to its design.
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Chiou, Richard Y., et Lin Lu. « Analysis of Tension Effect on Chatter Stability in Machining ». Dans ASME 2002 International Mechanical Engineering Congress and Exposition. ASMEDC, 2002. http://dx.doi.org/10.1115/imece2002-39115.

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This paper presents an analysis of the effect of tension on machining stability. It studies the mechanism of a self-excited vibration process by applying a tension force in the axial direction in a turning operation. This research investigates the tension effect on machining stability and develops a comprehensive model for the simulation of stability resulting from the axial tension force in machining, particularly for those applications in cutting long, slender, or thin materials. In addition, a new tension-fixturing technology is introduced to maximize stability and minimize undesirable chatter vibration in machining. The research can lead to a better understanding of stability and control of the cutting processes. It also can improve the traditional clamping method and provide important information in the design of the machine tool system, as well as in the planning, optimization, and production control for cutting processes. Following the theoretical analysis, an experimental study on chatter boundary illustrates the tension effect on machining stability. A comparison between the predicted and experimentally measured stability boundary, over a range of cutting conditions, shows favorable agreement.
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Chandan, Rahul, Dario Paccagnan et Jason R. Marden. « The Tension Between Anarchy and Stability in Congestion Games ». Dans 2022 American Control Conference (ACC). IEEE, 2022. http://dx.doi.org/10.23919/acc53348.2022.9867335.

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Rapports d'organisations sur le sujet "Stabilite tension"

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Walshire, Lucas, Joseph Dunbar et Benjamin Breland. Stability analysis of Old River Low Sill Structure. Engineer Research and Development Center (U.S.), septembre 2022. http://dx.doi.org/10.21079/11681/45349.

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An updated stability analysis was performed on the Old River Low Sill Structure due to a change in the operating conditions from historic river sedimentation. Sedimentation of the Mississippi River channel since the 1973 spring flood has caused higher river stages at lower discharges. Numerical methods used included nonlinear analysis of pile group stability, seepage analyses, and limit equilibrium methods. The structure’s foundation was compromised during the 1973 flood, and emergency repairs were conducted to prevent scouring and undermining of the foundation by the flood scour. Rehabilitation included the reconstruction of a failed wing wall on the left abutment, rock and riprap fill in the forebay channel, and emergency grouting to fill the scour hole beneath the structure. An operating restriction was emplaced to limit the differential head across the structure due to flood damage. Taking these conditions into account, results from an updated analysis showed that full headwater uplift caused increased tension in the piles, while the increased body load caused increased compressive loads in the piles. Review of piezometric monitoring and the seepage analyses showed that full headwater uplift is unlikely, indicating the foundation grouting adequately sealed the scour hole beneath the structure. Analysis results exhibited lower magnitude compression and tension loads in the piles with design load cases compared to previous analyses. Recommendations from these analyses indicate that increased monitoring and additional investigation may support increasing the differential head limitation.
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Hull, Andrew J., Benjamin A. Cray et Albert H. Nuttall. Stability Analysis of a Tensioned String With Periodic Supports. Fort Belvoir, VA : Defense Technical Information Center, mai 2007. http://dx.doi.org/10.21236/ada470346.

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Klueh, R. L. Tensile behavior of irradiated manganese-stabilized stainless steel. Office of Scientific and Technical Information (OSTI), octobre 1996. http://dx.doi.org/10.2172/414884.

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Unknown, Author. PR-213-9103-R01 Capabilities-Limitations of the S-Curve Pipelay Method. Chantilly, Virginia : Pipeline Research Council International, Inc. (PRCI), septembre 1991. http://dx.doi.org/10.55274/r0011969.

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Evaluated the typical Gulf of Mexico pipelay barges and assess their ability to install 8 to 20-inch diameter pipelines in water depths ranging from 1000 ft to 3000 ft. McDermott's LB-29 and DB-28, Global Pipelines PLUS' Cherokee, and OPI's DLB-423 were evaluated. Allseas' the North Sea dynamically positioned lay vessel Lorelay was also evaluated for comparison. Pipe wall thicknesses to satisfy buckle propagation, collapse, and stability criteria were determined, and the results were used to select wall thicknesses for 8, 12, 16, and 20-inch nominal pipe diameters in water depths of 1000, 1500, 2000, 2500, and 3000 feet. The selected wall thickness and diameters were then used as inputs for a finite element model to determine stinger and tensioner requirements for each vessel. Each vessel's mooring system was analyzed to assure satisfactory performance, after taking into account pipe-induced tensions and environmental loads resulting from a 1.5-knot current and a 30-knot wind. Mooring system upgrading options include the use of anchor chains or additional mooring line pendants. The scope of work did not include dynamic pipe stress, dynamic mooring system analysis, vessel motions analysis, or move-up analysis.
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Hassan, Saeed, AbdulKhaliq Alshadid, Ravinder Saini et Lujain Aldosari. Assessment of Mechanical Properties of Hybrid PVES Elastomeric Material in Comparison to its Parent Materials - A Systemic Review. INPLASY - International Platform of Registered Systematic Review and Meta-analysis Protocols, mars 2023. http://dx.doi.org/10.37766/inplasy2023.3.0043.

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Review question / Objective: Does the hybrid elastomeric impression materials have better elastic memory, tensile strength, hydrophilicity, and dimensional stability as compared to polyether and poly vinyl siloxane. Condition being studied: Dimensional Stability, Tear Strength, yield strength, wettability and other properties of impression materials. Information sources: Original studies from corresponding databases were exported using Harzing’s Publish or Perish (Tamra Software Research Ltd) Widows GUI v8.8 edition with MeSH keywords. Data was exported to MS Excel 2021 edition (Microsoft Corporation, Washington USA).
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Melanson III, Lester M. The Rearmament of Japan : Increased Regional Stability in the Western Pacific or Unnecessary Increase in Tensions. Fort Belvoir, VA : Defense Technical Information Center, mai 2011. http://dx.doi.org/10.21236/ada546105.

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Youngblood, G. E., C. H. Jr Henager, D. J. Senor, G. A. Newsome et J. J. Woods. Dimensional stability and tensile strength of irradiated Nicalon-CG and Hi-Nicalon SiC fibers. Office of Scientific and Technical Information (OSTI), mai 1997. http://dx.doi.org/10.2172/319772.

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Subramanian, K. H. Tensile Properties for Application to Type I and II Waste Tank Flaw Stability Analysis. Office of Scientific and Technical Information (OSTI), septembre 2000. http://dx.doi.org/10.2172/764654.

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Terzyan, Aram. Post-Soviet State - Building in Kyrgyzstan : Behind and Beyond the Revolutions. Eurasia Institutes, avril 2021. http://dx.doi.org/10.47669/caps-1-2021.

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This paper explores post-Soviet state-building in Kyrgyzstan, with a focus on the root causes of the three revolutions faced by the country. It suggests that the revolutions have not produced significant results in terms of fundamental economic and political reforms. Rather, Kyrgyzstan has turned into the Central Asian “island of instability”. The situation is compounded by deep- rooted inter-ethnic tensions, the prevalence of traditional informal institutions and weakness of democratic institutions, as well as country’s heavy reliance on international donors. The presidential elections and constitutional referendum of 2021 have provided grounds for cautious optimism. A question remains of whether and to what extent Sadyr Japarov’s ambitious agenda will translate into reality, thus leading the country to prosperity and stability.
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Egeresi, Zoltán. More than one Year Later : an Evaluation of the Geopolitical Implications of the Second Karabakh War. Külügyi és Külgazdasági Intézet, 2022. http://dx.doi.org/10.47683/kkielemzesek.ke-2022.05.

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This paper describes the background and main cornerstone of the Nagorno-Karabakh conflict and reveals the main geopolitical outcomes of the second Karabakh war. It argues that the war has caused a major geopolitical shift in the region, as it has cemented Russia’s military presence in Karabakh, thus creating a frozen conflict despite the Azerbaijani victory and territorial gains. Furthermore, it has also strengthened the position of Turkey in the region and boosted the Azerbaijani-Turkish alliance, which gathered pace throughout 2021. However, other regional actors such as Iran see this change as increasingly threatening. Various attempts to create a regional forum to mend fences and establish stability have had limited results, thus tensions remain permanent in the South Caucasus.
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