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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Effect of jet configuration on transverse jet mixing process

Kim, Sin Hyen 12 July 2011 (has links)
Transverse jets in crossflow are widely used to enhance mixing between two flow streams. Such jets exhibit complex flow features, and are highly sen- sitive to a wide variety of operating conditions. The focus of this work is the mixing of relatively low Reynolds number jets that are often encountered in the chemical processing industry. The main objective is to determine if the the jet mixing characteristics can be sufficiently altered by changing the nature of the jet inflow. In particular, we study the effect of jet shape and inflow veloc- ity profile on the mixing properties. Four different jet shapes including circle, square, upstream triangle, and downstream triangle are considered. It is found that the jet shape has tremendous impact on the near field dynamics, gener- ating unique vortical structures for each shape. However, the overall mixing rate is unaffected and is controlled by the evolution of the coherent vortex pair (CVP) in the far-field of the jet. Analyses of turbulence modeling constraints and structure of reaction zones for consecutive-competitive reactions are also presented. / text
22

Transient and Pseudosteady-State Productivity of Hydraulically Fractured Well

Lumban Gaol, Ardhi 2012 August 1900 (has links)
Numerical simulation method is used in this work to solve the problem of transient and pseudosteady-state flow of fluid in a rectangular reservoir with impermeable boundaries. Development and validation of the numerical solution for various well-fracture configurations are the main objectives of this research. The specific case of horizontal well intersected by multiple transverse fractures is the focus of the investigation. The solutions for different operating conditions, constant rate and constant pressure, are represented in the form of transient – peudosteady-state productivity indices. The numerical simulator is validated by comparing results to known analytical solution for radial flow, existing models of productivity for vertical well intersected by vertical fracture, and also with published tables of shape factors. Numerical simulation is a powerful tool to predict well performance. The complexities of well-fracture configurations can be modeled in a truly 3-dimensional system and the pressure and productivity responses for all of the flow regimes can be computed efficiently, enabling optimization of the well-fracture system.
23

Materials with Axis-Dependent Conduction Polarity and their Application in Transverse Thermoelectric Devices

Scudder, Michael Richard January 2021 (has links)
No description available.
24

Transverse Vibrations of a Beam Having Nonlinear Constraint

Kumar, Rajnish 03 1900 (has links)
<p> Transverse vibrations of a beam with one end fixed and the other supported on nonlinear spring have been studied. Theoretical analysis has been carried out for two different cases of springs, viz.; cubic nonlinear and bilinear types. </p> <p> Theoretical results for bilinear case have been compared with those obtained experimentally. The effect of end mass has also been considered in theoretical analysis. </p> / Thesis / Master of Engineering (MEngr)
25

Les représentations du loup garou de l’Antiquité à nos jours : une étude au long cours d’un mythe qui se recharge au fil du temps / Werewolves depictions through centuries : a long-term study of a myth that recharges over time

Trevily, Julie 25 January 2019 (has links)
Cette thèse de doctorat met en oeuvre une analyse transverse au long cours des figures représentant le loup garou à travers les siècles. L’objet de cette enquête est multiple : trouver les fondements du mythe, voir dans quelle mesure il s’est transmis par le biais des élites, comprendre la valeur de la créature d’un point de vue sociologique. Pour résumer l’ensemble, il s’agit de voir comment, depuis l’Antiquité jusqu’à nos jours, ce mythe a traversé les époques, perdant ou gagnant des éléments d’identité mais se rechargeant toujours assez pour rester évocateur de la société qui l’entoure. Malgré la difficile prise en compte des sources très anciennes, celles de la mythologie par exemple – un travail de mise en perspective s’est construit autour de la perception, de la représentation du loup garou comme moyen de questionner l’homme et sa valeur au cours des différentes périodes historiques qui voient évoluer sa valeur de manière tantôt positive, tantôt négative. Ces changements s’expliquent par le poids des guerres, par celui des institutions, mais aussi par la pression, parfois terrible, de canis lupus sur le territoire français. Ce mythe, international et très populaire aujourd’hui, offre de nombreuses possibilités de questionner nos comportements, peurs et attentes, au travers de versions plus ou moins romantiques, plus ou moins réalistes, en fonction des médias choisis, comme nous le montrent les différentes œuvres étudiées depuis l’Antiquité jusqu’à nos jours. / This PhD thesis aims to put emphasis on a long course analysis of werewolves depictions through centuries. This investigation has several aspects : finding the werewolf myth foundations, seeing how it could have spread via elite society, understanding creature’s value on a sociologic way… This thesis involves seeing how, from Antiquity to now, the myth has traveled through times and centuries, gaining or losing identity elements, but always recharging itself in order to stay evocative of the society surrounding it. In spite of the difficulty in trusting very ancient sources, as mythology for example, serious standpoint creation has grown on perceptions, depictions of werewolf as a mean to question human being and his value through different historical periods specific to it, and where its value changes from positive to negative and inversely. Those changes can be explained by the weight of wars, institutions, but also by the pressure, sometimes terrible, of canis lupus on European and French territories. This myth of werewolf, international and very popular today, offers many ways of questioning our habits, fears, hopes through different versions, more or less romantic, more or less realistic depending on the chosen media, as we can notice in the different masterpieces from Antiquity until today.
26

Nuclear effects in high-energy proton-nucleus collisions : transverse momentum broadening of energetic parton systems and soft anomalous dimension matrices / Effets nucléaires dans les collisions proton-noyau à haute énergie : élargissement de l’impulsion transverse des systèmes de partons énergétiques et matrices de dimension anormale

Cougoulic, Florian 21 September 2018 (has links)
Dans le Modèle Standard de la physique des particules, la théorie de l’interaction forte, la chromodynamique quantique (QCD), est une théorie de jauge de groupe de symétrie SU (Nc) par rapport au nombre quantique de couleur. QCD obéit à la propriété de liberté asymptotique, permettant le calcul d’observables physiques à haute énergie en utilisant la QCD perturbative (pQCD). Cette thèse traite de la description en pQCD des taux de production de hadrons dans les collisions hadroniques à haute énergie, en vue d’applications à la phénoménologie des collisions proton-noyau et noyau-noyau dans les collisionneurs de hadrons (RHIC, LHC), où des effets nucléaires (shadowing, perte d’énergie partonique, élargissement de l’impulsion transverse) entrent en jeu. Dans une première partie, j’étudie l’élargissement de l’impulsion transverse d’un système de partons énergétiques traversant un noyau, en mettant l’accent sur la structure de couleur du processus. Un cadre théorique basé sur le formalisme des dipôles est utilisé, et une équation cinétique est dérivée pour la distribution en impulsion transverse de la paire de partons, en demandant que cette paire soit dans un état de couleur donné (représentation irréductible de SU (Nc)) à la fois dans l’état initial et dans l’état final. La structure de couleur est codée dans un opérateur d’évolution de couleur, qui est obtenu pour tout type de paire de partons. Pour une paire compacte de petite taille, la dérivation donne une interprétation physique claire du processus d’élargissement de l’impulsion transverse. Dans une deuxième partie, je discute la matrice de dimension anormale Q, qui est formellement analogue à l’opérateur d’évolution précédent, et qui apparaît lors de l’ étude du rayonnement de gluons mous associé à une diffusion partonique dure 2 −> 2. Il a été remarqué que la matrice Q associée à gg −> gg a une symétrie surprenante (reliant les degrés de liberté externe et interne). J’ai développé des outils pour dériver les matrices Q associées à des diffusions 2 −> 2 impliquant des partons généralisés, afin d’explorer si la symétrie observée pour gg −> gg est fortuite ou non. / In the Standard Model of particle physics,the theory of the strong interaction, Quantum Chromodynamics (QCD), is a gauge theory of symmetry group SU (Nc) with respect to the color quantum number. QCD obeys the property of asymptotic freedom, allowing the computation of high-energy physical observables using perturbative QCD (pQCD). This thesis deals with the pQCD description of hadron production rates in high-energy hadronic collisions, in view of applications to the phenomenology of proton-nucleus and nucleus-nucleus collisions at hadron colliders (RHIC,LHC), where so-called nuclear effects (shadowing, parton energy loss, transverse momentum broadening) come into play. In a first part, I study the transverse broadening of an energetic parton system crossing a nucleus, putting emphasis on the color structure of the process. A theoretical setup based on the dipole formalism is used,and a kinetic equation is derived for the parton pair transverse momentum distribution, requiring the parton pair to be in a given color state (SU (Nc) irreducible representation) both in the initial and final state. The color structure is encoded in a color evolution operator, which is obtained for any type of parton pair. For a small-size compact pair, the derivation yields a transparent physical interpretation of the pair transverse broadening process. In a second part, I discuss the soft anomalous dimension matrix Q, which is formally analogous to the previous evolution operator, and which appears when studying soft gluon radiation associated to 2 −> 2 hard parton scattering. It has been noticed that the Q-matrix associated to gg −> gg has a surprising symmetry (relating external and internal degrees of freedom). I developed tools to derive the Q-matrices associated to2 −> 2 scatterings involving generalized partons, in order to explore if the symmetry observed for gg −> gg is fortuitous or not.
27

Azimuthal decorrelation between leptons in the Drell-Yan process as a probe of infrared QCD : phenomenology, predictions and measurement of a novel collider observable using perturbative resummation techniques

Tomlinson, Lee January 2014 (has links)
This thesis presents phenomenological studies of a state-of-the-art NNLL+NLO theoretical calculation of a novel collider observable known as 'phi star'. In these studies the 'phi star' observable, a measure of azimuthal decorrelation, is applied directly to the leptons in the production of massive lepton pairs in hadron collisions (the Drell-Yan process). This provides an alternate measure of the recoil of the massive vector boson (Z/gamma) against initial state QCD radiation, but with distinct experimental advantages over the traditional boson transverse momentum. Attention is focused on the small-'phi star' regime (the quasi-back-to-back regime) where the infrared dynamics of soft/collinear gluon emissions become important. These phenomenological studies are followed up with the presentation of a measurement of 'phi star' in 'Z to mu mu' events using 20.3 fb^-1 of collision data collected by the ATLAS experiment in 2012. Finally, studies directly related to the ATLAS absolute luminosity calibration by the van der Meer (vdM) method are presented, with the objective of elucidating the role of transverse linear beam correlation. In particular, I present studies using an analytical method I have developed in order to precisely extract individual beam information by way of studying phenomena pertaining to the luminous region during vdM scans. In addition, a dedicated study of the long- and short-term stabilities of the principal detectors for luminosity monitoring is also presented, along with an appropriate recalibration of these detectors.
28

Detailed analysis of the transverse arch of hallux valgus feet with and without pain using weight-bearing ultrasound imaging and precise force sensors / 荷重時の超音波画像と力センサーによる痛みの有無による外反母趾足の横アーチの詳細分析

Zeidan, Hala 23 March 2020 (has links)
付記する学位プログラム名: 充実した健康長寿社会を築く総合医療開発リーダー育成プログラム / 京都大学 / 0048 / 新制・課程博士 / 博士(人間健康科学) / 甲第22388号 / 人健博第74号 / 新制||人健||5(附属図書館) / 京都大学大学院医学研究科人間健康科学系専攻 / (主査)教授 黒木 裕士, 教授 高桑 徹也, 教授 妻木 範行 / 学位規則第4条第1項該当 / Doctor of Human Health Sciences / Kyoto University / DFAM
29

Seismic Retrofit of Concrete Columns by Transverse Prestressing

Sabri, Amirreza 09 September 2013 (has links)
Performance of buildings and bridges during past earthquakes has indicated that many of these structures are vulnerable to seismic damage and structural collapse. The deficiencies in pre-1970s design codes have resulted in poor performance of reinforced concrete structures during seismic excitations. The Richter Magnitude 6.6 - 1971 San Fernando Earthquake raised awareness for seismic retrofit needs of existing buildings for the first time. The majority of deficiencies of vulnerable concrete columns can be overcome through seismic retrofits that involve additional transverse reinforcement. This can be done either by providing reinforced concrete, steel, or fibre-reinforced polymer (FRP) jackets around existing columns; or by applying transverse prestressing to columns (RetroBelt System). The research project presented in this thesis involves a seismic retrofit methodology for seismically deficient building and bridge columns, utilizing the use of high-strength packaging straps as external reinforcement for transverse prestressing. The emphasis in the project is placed on experimental research. Three seismically deficient full-size reinforced concrete columns, with a circular, a square and a rectangular cross- section, either critical in shear or flexure, were designed, built and tested under simulated seismic loading. The results indicate that external prestressing of columns in transverse direction with high-strength steel straps improves ductility and energy dissipation capacity of seismically deficient columns. They further indicate that current analytical techniques can be used to predict the force-displacement relationships of columns. A design approach is presented for the retrofit methodology investigated.
30

Seismic Retrofit of Concrete Columns by Transverse Prestressing

Sabri, Amirreza January 2013 (has links)
Performance of buildings and bridges during past earthquakes has indicated that many of these structures are vulnerable to seismic damage and structural collapse. The deficiencies in pre-1970s design codes have resulted in poor performance of reinforced concrete structures during seismic excitations. The Richter Magnitude 6.6 - 1971 San Fernando Earthquake raised awareness for seismic retrofit needs of existing buildings for the first time. The majority of deficiencies of vulnerable concrete columns can be overcome through seismic retrofits that involve additional transverse reinforcement. This can be done either by providing reinforced concrete, steel, or fibre-reinforced polymer (FRP) jackets around existing columns; or by applying transverse prestressing to columns (RetroBelt System). The research project presented in this thesis involves a seismic retrofit methodology for seismically deficient building and bridge columns, utilizing the use of high-strength packaging straps as external reinforcement for transverse prestressing. The emphasis in the project is placed on experimental research. Three seismically deficient full-size reinforced concrete columns, with a circular, a square and a rectangular cross- section, either critical in shear or flexure, were designed, built and tested under simulated seismic loading. The results indicate that external prestressing of columns in transverse direction with high-strength steel straps improves ductility and energy dissipation capacity of seismically deficient columns. They further indicate that current analytical techniques can be used to predict the force-displacement relationships of columns. A design approach is presented for the retrofit methodology investigated.

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