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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.
71

Absolutely Pure Modules

Pinzon, Katherine R. 01 January 2005 (has links)
Absolutely pure modules act in ways similar to injective modules. Therefore, through-out this document we investigate many of these properties of absolutely pure modules which are modelled after those similar properties of injective modules. The results we develop can be broken into three categories: localizations, covers and derived functors. We form S1M, an S1R module, for any Rmodule M. We state and prove some known results about localizations. Using these known techniques and properties of localizations, we arrive at conditions on the ring R which make an absolutely pure S1Rmodule into an absolutely pure Rmodule. We then show that under certain conditions, if A is an absolutely pure Rmodule, then S1A will be an absolutely pure S1Rmodule. Also, we dene conditions on the ring R which guarantee that the class of absolutely pure modules will be covering. These include R being left coherent, which we show implies a number of other necessary properties. We also develop derived functors similar to Extn R (whose development uses injective modules). We call these functors Axtn R, prove they are well dened, and develop many of their properties. Then we dene natural maps between Axtn(M;N) and Extn(M;N) and discuss what conditions on M and N guarantee that these maps are isomorphisms.
72

An analysis of modular patterns in healthy and post-stroke hemiparetic gait

Routson, Rebecca Linn 06 November 2014 (has links)
Recent studies have suggested the biomechanical subtasks of walking can be produced using a reduced set of co-excited muscles or modules. Individuals post-stroke often exhibit poor inter-muscular coordination characterized by poor timing and merging of modules that are normally independent in healthy individuals. However, whether locomotor therapy can influence module quality (timing and composition) and whether these improvements lead to improved walking performance is unclear. Further, it is unknown whether the same modules that produce self-selected walking can also produce the execution of different mobility tasks. In this study, experimental analyses were used to compare module quality pre- and post-therapy. In subjects with four modules pre- and post-therapy, locomotor training resulted in improved timing of the ankle plantarflexor module and a more extended paretic leg angle that allowed the subjects to walk faster with more symmetrical propulsion. In addition, subjects with three modules pre-therapy increased their number of modules and improved walking performance post-therapy. Thus, locomotor training was found to influence module composition and timing, which can lead to improvements in walking performance. Experimental and simulation analyses were then used to characterize modular organization in specific mobility tasks (walking at self-selected speed with maximum cadence, maximum step length, and maximum step height). We found that the same underlying modules (number and composition) in each subject that contribute to steady-state walking also contribute to the different mobility tasks. In healthy subjects, module timing, but not composition, changed when the task demands were altered. This adaptability in module timing, in addition to the ability to adapt to the changing task demands, was limited in the post-stroke subjects. The primary difference in the execution of the walking biomechanical subtasks occurred in the control of the leg during pre-swing and swing. To increase cadence, the ankle plantarflexors and dorsiflexors contributed more power to the ipsilateral leg in pre-swing and swing, respectively. To increase step height, the hamstrings provided energy to the ipsilateral leg that accelerated the leg into swing in pre-swing and swing. These results provide a first step towards linking impaired module patterns to mobility task performance in persons post-stroke. / text
73

Serre Weights: The Partially Ramified Case

Smith, Ryan Bixby January 2012 (has links)
We study the possible weights of an irreducible 2-dimensional modular mod p representation of Gal (F/F), where F is a totally real field in which p is allowed to ramify, and the representation is tamely ramified at primes above p. We describe a set of possible weights and completely determine the weights in some cases when e = 2, f = 2.
74

Investigation of the reliability of the encapsulation system of photovoltaic modules

Wu, Dan January 2015 (has links)
Good reliability of the encapsulation system of Photovoltaic (PV) modules is crucial to ensure the long-term performance of PV modules. A carefully controlled lamination process is required to produce a reliable encapsulation system. To date, the influences of different lamination conditions on the reliability of the encapsulation system are poorly understood. To predict the performance of the encapsulation system, the correlation of the reliability of the encapsulation system with various stress levels is required, which is poorly developed. This thesis improves the understanding of these issues by investigating the correlation of different lamination conditions with the reliability of the encapsulation system and the degradation of adhesion strength under variable damp-heat conditions. The influence of the curing temperature and curing time on the long-term reliability of the encapsulation system is investigated from various viewpoints such as curing level of EVA, chemical and optical stability of EVA and adhesion strength within the encapsulation system. The correlation of curing level and lamination quality has been identified. The effects of over-curing are demonstrated. Results show that the chemical stability, optical stability and the adhesion strength between encapsulant and backsheet increases with the increasing curing level. However, the best long-term adhesion performance at the glass-encapsulant interface is obtained at lower gel content. Too high curing can cause problems of bubble generation, discoloration and unstable interfaces. Among those identified degradation phenomena, interfacial adhesion strength demonstrates the fastest and the largest degradation. The reliability of the adhesion strength is further examined under different stress levels. Among different environmental stress factors, moisture is considered to cause the greatest problems of adhesive interfacial stability. Therefore, the adhesion strength is investigated under different damp-heat conditions. A methodology is developed that can be used to model the adhesion degradation induced by moisture at different humidity and temperature conditions. To do so, a stress model is established which enables quantitative description of the moisture related stresses on PV modules. Based on this model, an exponential correlation is established between the adhesion strength and the humidity and temperature levels. This enables the comparison of adhesion strength of PV modules operating at different humid environments.
75

Sur la 2-cohomologie non abélienne : corps des modules / On the non abelian 2-cohomology : field of moduli

Djamaï, Bénaouda 16 May 2008 (has links)
Soit f : X ? Y un morphisme de schémas et G un Y -schéma en groupes. Lorsque G est abélien, la suite spectrale de Leray associée à f, Ep,q= Hp(Y,Rq,f.Gx)=> Hp+q(X,Gx), nous donne une suite exacte en basses dimensions : 0 ?H1(Y,f*G_x)? H1(X,Gx)?H0(Y,R1f*Gx)? H2(Y,f*Gx)?H2(X, Gx)tr?H1(Y,R1f*Gx)?H3(Y,f*Gx). Le but de ce travail est d'étudier l'analogue de cette situation lorsque G n'est plus abélien. La notion de gerbe introduite par Grothendieck permet de construire un substitut au cobord d0,1H0(Y,R1f*Gx)? H2(Y,f*Gx). Ici nous étudions plus particulièrement l'obstruction à descendre une Gx-gerbe sur X en une f*Gx-gerbe sur Y. Pour cela, à partir de l'interprétation de Giraud du R1f*Gx, nous construisons un substitut non abélien du H1(Y,R1f*Gx) et du cobord d1.1 :H1(Y,R1f*GX)?H3(Y, f*Gx), en termes de condition de corps des modules et de 2-gerbes. Nous donnerons ensuite deux exemples de descente de gerbes dans le cas non abélien: le premier, considéré par Grothendieck, est celui des surface fibrées sur des droites, le deuxième, de nature arithmétique, concerne l'extension maximale abélienne d'un corps des fractions d'un anneau local, excellent, henselien de dimension 2. / Let f: X-Y be a morphism of schemes and G a group scheme over Y. If G is abelian, the Leray spectral sequence associated to f, Epq=HP(Y, Rqf*Gx)==>Hp+q(X,Gx), gives rise to an exact sequence in low dimensions: 0- H1(y ,f*Gx)- H1 (X,Gx)- W(Y,R If*GX)_ H2(y ,f*Gx)- H2(X, Gx)tr_ H1(Y,R1f*GX)_ H3(Y,f*Gx). ln this thesis, we consider the case of a non abelian group G. The notion of a gerb, due to Grothendieck allows us to get an equivalent morphism to d0,1:H0(Y,R1f*Gx)-H2(Y,f*Gx). Here we study the obstruction to a Gx-gerb on X to be the image of an f*Gx-gerb on Y. For this aim, we use the Giraud's iterpretation ofR1f*Gx, to build an equivalent object to H1(Y,R1f*Gx) and an equivalent morphism to d1,1: H1(Y,R1f*Gx)_H3(Y,f*GX), in terms of field of moduli condition and 2-gerbs. We will then give two results in the non abelian case: a cohomological one, wich is the case of a surface fibred on a curve, studied by Grothendieck, and a arithrnetical one wich deals with the maximal abelian extension of the fractions field of a local, heselian, excellent ring of dimension 2.
76

Le gène cse, de création récente, code une hydrolase du peptidoglycane impliquée dans la séparation des cellules de Streptococcus thermophilus / The cse gene, recently created, encodes a cell-wall hydrolase involved in cellular separation in Streptococcus thermophilus

Layec, Séverine 07 November 2008 (has links)
Streptococcus thermophilus est une bactérie lactique utilisée dans l’industrie laitière pour la fabrication de yaourts et de divers fromages. S. thermophilus se développe en chaîne de cellules. Le mécanisme de la séparation des cellules n’est pas connu chez S. thermophilus. Un mutant de S. thermophilus présentant des chaînes de cellules extrêmement longues a été caractérisé. Le gène identifié est nommé cse pour cell separation. La particularité de cse est qu’il résulte d’un réassortiment de modules. En effet, l’analyse a montré que son extrémité 5’ est homologue à celle de sip de S. salivarius, tandis que son extrémité 3’ est homologue à celle de pcsB de S. thermophilus. Le gène cse spécifique de S. thermophilus code une protéine modulaire. A son extrémité N-terminale, Cse possède un peptide signal et un domaine de liaison à la paroi, LysM. Et à son extrémité C-terminale, Cse possède un domaine CHAP, présent dans les hydrolases du peptidoglycane. Dans cette étude, la localisation de Cse à la surface des cellules de S. thermophilus a été réalisée par microscopie électronique à transmission et immunofluorescence à l’aide d’anticorps dirigés contre cette protéine. Cse est localisée spécifiquement aux septa matures de S. thermophilus. De plus, l’activité de Cse a été démontré par zymogramme et présente une activité lytique qui est conférée par son domaine CHAP. L’analyse par RP-HPLC des muropeptides de la paroi de S. thermophilus après digestion avec le domaine CHAP a révélé que Cse est une hydrolase du peptidoglycane et plus précisément une endopeptidase. L’ensemble de ces résultats montre que Cse est l’enzyme majeure de la séparation cellulaire de S. thermophilus. / Streptococcus thermophilus is a lactic bacteria used a stater of fermentation in dairy factories for the production of yogurt and many cheeses. S. thermophilus grows as chains of ovoid cells. However, the genetic basis of S. thermophilus cell separation is still unknown. A S. thermophilus mutant displaying extremely long chains of cells was characterized and demonstrated to be impaired a gene that we named cse for cell separation. The originality of this gene is that cse creation resulted from domain shuffling. Indeed, the analysis has revealed that its 5’extremity has homology with that of sip from S. salivarius, while its 3’extremity shares homology with pcsB from S. thermophilus.The cse gene specific from S. thermophilus, encodes a modular protein. The N-terminal end of Cse contains a secretion signal and cell-wall binding LysM domain. Its C-terminal end includes a CHAP domain found in bacterial cell-wall hydrolases. In this study, the localization of Cse on S. thermophilus cell surface has been undertaken by immunogold electron and immunofluorescence microscopies using of antibodies raised against this protein. Immunolocalization shows that the presence of the Cse protein at mature septa. Moreover, the CHAP domain of Cse exhibits a lytic activity on the cell wall of S. thermophilus that has been demonstrated by zymogram. Additionally, RP-HPLC analysis of muropeptides released from S. thermophilus after digestion with the CHAP domain shows that Cse is a cell wall hydrolase that can function as an endopeptidase. Alltogether, these results suggest that Cse is a major cell wall hydrolase involved in daughter cell separation of S. thermophilus.
77

Design and Evaluation of an Online Pharmacy Preceptor Training Module

Bulthuis, Alisha, Riley, Heidi January 2007 (has links)
Class of 2007 Abstract / Objectives: The purpose of this study is to design and evaluate an online preceptor education module for pharmacy preceptors at the University of Arizona. Methods: A computer-based preceptor teaching program was developed and made available online. In order to evaluate this program, a focus group was conducted with pharmacy preceptors from the Southern Arizona VA Healthcare System. Additionally, a brief questionnaire collecting demographic data was administered. Results: A 60-minute computer-based program was developed for teaching microskills (e.g. setting goals and expectations). The seven preceptors who participated in the focus group liked the program design and content. They found the format and subject matter useful in precepting students and found the cases presented to be applicable to students they had encountered. The preceptors also showed interest in future programs of this nature. Conclusions: Preceptors found a computer module using slides and audio to teach microskills useful and indicated that it would improve their ability to precept students.
78

Period integrals and other direct images of D-modules

Tveiten, Ketil January 2015 (has links)
This thesis consists of three papers, each touching on a different aspect of the theory of rings of differential operators and D-modules. In particular, an aim is to provide and make explicit good examples of D-module directimages, which are all but absent in the existing literature.The first paper makes explicit the fact that B-splines (a particular class of piecewise polynomial functions) are solutions to D-module theoretic direct images of a class of D-modules constructed from polytopes.These modules, and their direct images, inherit all the relevant combinatorial structure from the defining polytopes, and as such are extremely well-behaved.The second paper studies the ring of differential operator on a reduced monomial ring (aka. Stanley-Reisner ring), in arbitrary characteristic.The two-sided ideal structure of the ring of differential operators is described in terms of the associated abstract simplicial complex, and several quite different proofs are given.The third paper computes the monodromy of the period integrals of Laurent polynomials about the singular point at the origin. The monodromy is describable in terms of the Newton polytope of the Laurent polynomial, in particular the combinatorial-algebraic operation of mutation plays an important role. Special attention is given to the class of maximally mutable Laurent polynomials, as these are one side of the conjectured correspondance that classifies Fano manifolds via mirror symmetry. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 1: Accepted. Paper 2: Manuscript. Paper 3: Manuscript.</p>
79

Affine Cellularity of Finite Type KLR Algebras, and Homomorphisms Between Specht Modules for KLR Algebras in Affine Type A

Loubert, Joseph 18 August 2015 (has links)
This thesis consists of two parts. In the first we prove that the Khovanov-Lauda-Rouquier algebras $R_\alpha$ of finite type are (graded) affine cellular in the sense of Koenig and Xi. In fact, we establish a stronger property, namely that the affine cell ideals in $R_\alpha$ are generated by idempotents. This in particular implies the (known) result that the global dimension of $R_\alpha$ is finite. In the second part we use the presentation of the Specht modules given by Kleshchev-Mathas-Ram to derive results about Specht modules. In particular, we determine all homomorphisms from an arbitrary Specht module to a fixed Specht module corresponding to any hook partition. Along the way, we give a complete description of the action of the standard KLR generators on the hook Specht module. This work generalizes a result of James. This dissertation includes previously published coauthored material.
80

Theory of distributive modules and related topics.

January 1992 (has links)
by Ng Siu-Hung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1992. / Includes bibliographical references (leaves 80-81). / Introduction --- p.iii / Chapter 1 --- Distributive Modules --- p.1 / Chapter 1.1 --- Basic Definitions --- p.1 / Chapter 1.2 --- Distributive modules --- p.3 / Chapter 1.3 --- Direct sum of distributive modules --- p.9 / Chapter 1.4 --- Endomorphisms of a distributive module --- p.13 / Chapter 1.5 --- Distributive modules satisfying chain conditions --- p.20 / Chapter 2 --- Rings with distributive lattices of right ideals --- p.25 / Chapter 2.1 --- Rings of quotients of right D-rings --- p.25 / Chapter 2.2 --- Localization of right D-rings --- p.28 / Chapter 2.3 --- Reduced primary factorizations in right ND-rings --- p.31 / Chapter 2.4 --- ND-rings --- p.38 / Chapter 3 --- Distributive modules over commutative rings --- p.43 / Chapter 3.1 --- Multiplication modules --- p.43 / Chapter 3.2 --- Properties of distributive modules over commutative rings --- p.48 / Chapter 3.3 --- Distributive modules over arithematical rings --- p.52 / Chapter 4 --- Chinese Modules and Universal Chinese rings --- p.59 / Chapter 4.1 --- Introduction --- p.59 / Chapter 4.2 --- Chinese Modules and CRT modules --- p.61 / Chapter 4.3 --- Universal Chinese Rings --- p.65 / Chapter 4.4 --- Chinese modules over Noetherian domains --- p.70 / Chapter 4.5 --- Remarks on CRT modules --- p.77 / Bibliography --- p.80

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