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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.
31

Implant Placement in Conjunction with the Ridge Split Technique

Harrison, Kevin Charles 27 July 2011 (has links)
No description available.
32

An Efficient Split-Step Digital Filtering Method in Simulating Pulse Propagation with Polarization Mode Dispersion Effect

He, Kan January 2007 (has links)
<p> The rapid increasing bandwidth requirement of communication systems demands powerful numerical simulation tools for optics fiber. The computational efficient, memory saving and stable are of the most important characteristics for any simulation tools used for long-haul and broadband optics fiber. An optimized split-step digital filtering method is developed in this paper. The concept of Fourier integral and Fourier series are used in extracting a FIR filter which is used to fit the original transfer function. A further optimization process which employs windowing technique to improve computation efficiency had also been done. Compared with split-step frequency method, our method improves the computation efficiency. Only simple shifts and multiplications are needed in our method. This optimized digital filtering method differs from the former digital filtering method in a sense that the filter length of the FIR filter we extracted is reduced to a very small number. The computation time can be saved as much as 96% than before. This method can also be used to solve coupled nonlinear Schrodinger equation which governs polarization mode dispersion effect in fibers. A new simulation scheme for PMD is proposed to save computation time. The propagation results shows good accordance to those already published results. </p> / Thesis / Master of Applied Science (MASc)
33

Interactions Between Grg (Groucho related gene) and Hes (Hairy/enhancer of split) Proteins in the Notch Signalling Pathway

Taylor, Catherine 06 1900 (has links)
<p> The Notch signalling pathway is a lateral inhibition pathway that serves to limit the number of cells in a proneural cluster (a group of equipotent cells) that will adopt a neural cell fate during neurogenesis in Drosophila. The proper segregation of neural and epidermal progenitor cells during neurogenesis requires the expression of both the proneural genes and the neurogenic genes. Expression of proneural genes, such as achaete, gives cells the potential to commit to a neural cell fate. The neurogenic genes encode proteins that act in the Notch signalling cascade and are required for cell fate determination during Drosophila neurogenests. Notch and Delta are neurogenic genes that encode large transmembrane proteins. Interaction between the extracellular domains of Notch and Delta is thought to transmit a signal to the nucleus by way of the DNAbinding Suppressor of Hairless protein. In response to Notch activation Suppressor of Hairless is translocated to the nucleus where it activates the transcription ofthe neurogenic genes ofthe Enhancer of split complex (E(spl)-C). The products of the E(spl)-C are bHLH transcription factors. They possess a Cterminal tryptophan-arginine-proline-tryptophan (WRPW) motif that interacts with the product of another neurogenic gene, groucho. The groucho gene product encodes a protein containing a WD40 repeat element. When bound to Groucho, E(spl) bHLH proteins are able to repress transcription of proneural genes, such as achaete, thereby directing the cell to adopt a non-neural cell fate.</p> <p> A number of murine groucho homologues have been identified and named Grg's (Groucho related genes). Three full length Grg proteins have been identified which contain all five domains found in the Drosophila Groucho protein. Two short Grg proteins have also been identified which only contain one of the domains found in the full-length Grg proteins. A number of murine homologues of the Drosophila E(spl)-C have also been identified and named Hes (Hairy/Enhancer of split) proteins. Like the gene products of the Drosophila E(spl)-C, the Hes proteins are bHLH proteins containing a C-terminal WRPW motif. One of the Hes proteins, Hes3, is lacking a basic domain and therefore lacks the DNA-binding activity possessed by the other Hes proteins. </p> <p> Attempts were made to detect interactions between Grg and Hes proteins using co-immunoprecipitation techniques. The anti-WD40 antibody, which recognizes the long WD40-containing Grg proteins, was able to specifically immunoprecipitate 35S-labelled Grgl . This antibody was also able to recognize WD40-containing Grg proteins present in Pl9 cell extracts. However, attempts to co-immunoprecipitate radiolabelled Hesl and AMLlb proteins with Grg proteins present in P19 cell extract were unsuccessful due to the low affinity of the antiWD40 antibody and the background caused by the binding of the test proteins to Sepharose. A second method of co-immunoprecipitation was attempted using an HA-tagged Grgl fusion protein and a commercially available anti-HA antibody. The attempt to co-immunoprecipitate 35S-labelled Hesl with radiolabelled HAtagged Grg 1 was unsuccessful due to a high degree of background caused by Hesl binding to protein G Agarose. Using the Yeast Two-Hybrid interaction assay, the WD40-containing Grg proteins, Grgl and Grg4, were found to interact with Hesl. However, using the same assay WD40-containing Grg proteins were found not to interact with Hes3, which lacks DNA-binding activity. A Western blot was performed to determine if the Hes3 fusion proteins were being expressed in transformed yeast but none were detected. This may have been due to the poor affinity of the anti-GAL4 activation domain antibody. A similar Western blot demonstrated that the Grg proteins, fused to the GAL4 DNA binding domain, were being expressed in transformed yeast extract. The WD40-containing Grg proteins, Grgl and Grg4, were also found not to interact with AMLlb, a protein which contains a C-terminal VWRPY domain which is reminiscent of the Cterminal WRPW interaction domain found in Hes proteins and Drosophila E(spl) proteins. However, WD40-containing Grg proteins were able to interact with an AML 1 b mutant in which the VWRPY motif was mutated to VWRPW in the Yeast Two Hybrid assay. </p> / Thesis / Master of Science (MSc)
34

Split-flow Stormwater Management Strategy Design Feasibility and Cost Comparison

Echols, Stuart Patton 10 December 2002 (has links)
This dissertation develops a new distributed split-flow stormwater management strategy and compares its site design feasibility and construction cost to existing stormwater management methods. The purpose of the split-flow strategy is to manage stormwater by preserving predevelopment flows in terms of rate, quality, frequency, duration and volume. This strategy emulates the predevelopment hydrology: it retains and infiltrates additional runoff volume created by development by using bioretention and paired weirs as proportional flow splitters connected to small infiltration facilities distributed throughout a site. Results show that 1) the distributed split-flow stormwater management strategy can provide a higher level of environmental protection at comparable construction cost to existing detention-based methods, 2) split-flow systems are less expensive to construct than current truncated hydrograph-based bioretention and infiltration systems and 3) non-point source water pollution-reduction objectives, currently achieved with either detention with first flush or comparable bioretention and infiltration systems, could be achieved in a more cost-effective manner using distributed split-flow stormwater management strategy. / Ph. D.
35

Oro taršos nustatymas naudojant hy split oro pernašos modelį ir izotopų santykio metodą / Determination of air pollution using Hysplit air transmission model and stable isotopes mass ratio method

Kaluškevičius, Gytis 22 January 2014 (has links)
Šiame darbe apžvelgiamos aerozolio dalelių savybės, jų sudėtis, tyrimo metodai ir poveikis klimatui. Nagrinėjamos jų matavimo technikos ir galimas poveikis klimatui, dėl kurio ir oro taršos kyla uždavinys tyrinėti aerozolio daleles Lietuvoje. Kadangi oro teršalai gali būti atnešti iš kitų valstybių, tai norint rūpintis aplinkos apsauga, reikia nustatyti jų kilmę, ištirti oro masių judėjimą. Atomo izotopų santykio matavimas gali padėti aptikti teršalus, o oro masių judėjimo modeliavimas naudojant hy split metodą - išsiaiškinti, iš kur jie kilę. Šiame darbe tam buvo panaudoti oro masių siurbimo, vykdyto Vilniuje, Fizikos institute, duomenys. Rezultatai rodo, kad dažniausiai oro masės į Lietuvą ateina nuo Atlanto vandenyno, taip pat nuo Rusijos ir Skandinavijos. Iš ten gali ateiti ir teršalai. / It is reviewing properties, research methods, composition, affects on climate of aerosols in this work. It analyses measurement techniques, affects on climate, because from it and air pollution it is useful to research particles of aerosols in Lithuania. Air pollutants can be transported from other countries, so we need to find out origin of aerosols and transmission of air masses to take care of environment. Measurement of atom isotopes ratio can help to find pollutants, and mases transmission modeling using hy split method - to find out origins. In this work air mass pumping in Vilnius, Institute of Physics, data was used for that purpose. Results shows that most frequently air masses comes to Lithuania from Atlantic ocean, and Russia and Scandinavia too. The pollutants can come from that locations.
36

Einfluss von Genotyp und Umwelt auf die N-Rhizodeposition von Leguminosen

Landgraf, Anke 01 February 2017 (has links) (PDF)
Im Rahmen der Untersuchungen wurde die N-Rhizodeposition verschiedener Futter- und Körnerleguminosen mittels Split-Root-Technik und kontinuierlicher 15N-Anreicherung quantifiziert. Anteilig an der gesamtpflanzlichen N-Menge unterschieden sich die durch Rhizodeposition abgegebenen N-Mengen zwischen den geprüften Leguminosenarten weder im Gewächshaus noch im Feld signifikant voneinander, so dass der Einflussfaktor Pflanzenart und –sorte auf die Höhe der spezifischen N-Rhizodeposition als eher gering einzuschätzen ist. Der Einfluss der Umwelt (Gewächshaus versus Freiland) auf die untersuchten Kenngrößen der Trockenmassen und N-Akkumulationen sowie der N-Rhizodeposition fiel hingegen sehr viel deutlicher aus. Die Untersuchungen zeigten zudem positive Zusammenhänge zwischen den N-Rhizodepositionsmengen und den Trockenmasseerträgen bzw. akkumulierten N-Mengen der Leguminosen.
37

Development of Orthogonal Split-Kinase and Split-Phosphatase Systems for Interrogating and Rewiring Signal Transduction

Castillo-Montoya, Javier, Castillo-Montoya, Javier January 2016 (has links)
The function of most proteins is regulated by post-translational modifications, of which phosphorylation in particular has been shown to be ubiquitous and of paramount importance to cell signaling. Two enzyme families, protein kinases and phosphatases, regulate phosphorylation, and aberrant activities of family members have been implicated in many diseases such as cancer and neurological disorders. Thus, understanding the function of these enzymes in living cells is important for understanding their biology and for designing new therapies, but a challenging task due to their highly conserved architecture. The major focus of the dissertation is on the development of a new approach to selectively turn-on multiple specific kinases and/or phosphatases using orthogonal ligands as chemical inducers of dimerization (CIDs). Specific kinases or phosphatases were dissected at particular sites into two inactive fragments or split-proteins. The split fragments are attached to interacting protein pairs of CID systems, such that upon addition of the specific ligand they heterodimerize with subsequent reassembly of the split-protein and concomitant activity. We demonstrated the in vitro and in cellulo feasibility of this approach using three orthogonal CIDs, rapamycin, abscisic acid, and gibberellic acid, to turn-on members of the tyrosine kinase group such as Lyn and Src, and of the tyrosine phosphatase group such as PTP1B and SHP1. We have also developed a new synthetic photocleavable di-trimethoprim CID that allows for ligand-gated turn-on of desired kinases in live cells. The new CID can be cleaved or turned-off by UV irradiation which results in a turn-off of kinase activity. Small molecule controlled split-proteins allow for developing logic gates and we demonstrate that the systems we have developed can be used to construct 7 out of the 10 basic, circuit-type Boolean phosphorylation-based logic gates in living cells. These post-translational logic gates may have interesting applications in synthetic biology. Finally, we present an initial approach to use redesigned kinases and redesigned ligands as potential scaffolds for developing new CIDs. Thus, we provide and extend new methodologies that potentially allow for posttranslational control over the activity of user defined split-kinases and split-phosphatases for interrogating and redesigning signaling pathways. The last section of this work focuses on understanding small-molecule selectivity toward protein kinases. We systematically analyzed different reported kinase screens to further understand the reliability of large scale data in the kinome field as the design of selective inhibitors is one the most useful approaches for understanding the function of enzymes or the development of drugs in a natural setting such as a primary cell or an organism.
38

Modelagem e controle de microturbina a gás do tipo split-shaft. / Modeling and control of slip-shaft gas microturbine.

Faria, Vítor Pereira 19 February 2010 (has links)
O objetivo deste trabalho é o desenvolvimento do modelo de uma microturbina a gás do tipo split-shaft com sistema de controle por retro-alimentação. Uma revisão bibliográfica dos trabalhos sobre controle de turbinas a gás indicou que praticamente inexistem trabalhos focando este tipo de turbina. O modelo foi desenvolvido a partir da geometria básica da turbina, aplicando-se os fundamentamentos de termodinâmica, mecânica newtoniana e mecânica dos fluidos mencionando os usos da primeira lei da termodinâmica, teoria de momento angular e atrito viscoso entre outros. O trabalho descreve os componentes, materiais e controles que podem ser usados em uma turbina split-shaft. O modelo foi simulado primeiramente sem controle e posteriormente com controle. Através dos resultados da simulação do modelo sem controle puderam ser vistos fenômenos que podem ocorrer em um sistema desse tipo como picos de temperatura, influência de uma turbina sobre a outra e a variação de injeção de combustível devido à variação de pressão na câmara de combustão entre outros. Para o modelo controlado, foram testados os controles PI, PID, PI-D, I-PD e PI-PD com feedback negativo. A escolha dos parâmetros de cada controle foi determinada pelo método ITAE dentro de um intervalo para cada parâmetro. O controle escolhido foi o PI-D por seu melhor desempenho e maior simplicidade. O controle fez com que as temperaturas de pico abaixassem em relação ao sistema sem controle e a rotação do gerador de energia elétrica foi mantida com uma variação máxima menor que 1% em relação à rotação de referência. Uma modelagem foi feita para um sistema lubrificante seguindo os mesmos princípios da modelagem da turbina split-shaft. Usou-se fundamentos de mecânica newtoniana e mecânica dos fluidos, com o equacionamento da conservação da quantidade de movimento, perdas de pressão localizada e distribuída entre outros. O modelo foi simulado primeiramente sem controle e posteriormente com controle. Através do modelo sem controle viu-se os efeitos do aumento da perda de carga em um dos ramos do sistema e os efeitos de uma entrada de referência em degrau. Esses efeitos são as variações das perdas no sistema e a variação do fluxo nos ramos do sistema. Para o modelo controlado foram testados os controles PI e PI-D com feedback negativo. Utilizou-se o método ITAE dentro de um intervalo para escolha dos parâmetros. O controle escolhido foi o PI porque a diferença de desempenho não foi significativa e a parte derivativa poderia tornar o erro maior devido à forma como o sistema foi modelado. A variável de processo foi controlada e os efeitos da variação de perda de carga em um dos ramos do sistema pôde ser observada. Os modelos são constituídos de várias partes simples, cada qual pode ser substituída por um modelo mais preciso. Assim, a modelagem funciona como um guia, mostrando as partes principais do sistema e podendo fornecer dados para a elaboração de novos modelos. / The objective of the present work is the development of the model of a split-shaft micro gas turbine with feed back control system. A bibliographical review of the works on control of gas turbines indicated that there are very few works dealing this type of gas turbines. The model was developed starting from the basic geometry of the turbine and applying the fundamentals of thermodynamics, newtonian mechanics and fluid mechanics. The components, materials and controls which can be used in a split-shaft turbine are described. The model is simulated firstly without control and later with control. The results showed that, for the uncontrolled model, typical phenomena which may happen in this type of system are seen such as temperature peaks, influence of one turbine on the other and fuel injection variation due to combustion chamber pressure variation amongst others. For the controlled model, the controls PI, PID, PI-D, I-PD and PI-PD with negative feedback are tested. The parameters choice of each control is determined by the ITAE method within an interval for each parameter. The PI-D control was chosen for its best performance and simplicity. The control made the peak temperatures lower than the uncontrolled system and the electricity generator rotation error was kept under 1% with respect to the reference value. A modeling is done for a lubrification system following the same principles of the split-shaft turbine modeling. Conservation laws of mechanics and fluid mechanics are used, such as momentum conservation and energy conservation equations (pressure loss). The model is simulated firstly without control and later with control. For the uncontrolled model, the effects on increasing the head loss in one branch of the system and the effects for a step reference was showed. These effects are the variations of system losses and the flow variation in the system branches. For the controlled model, the PI and PI-D controls with negative feedback were tested. The parameters choice of each control is determined by the ITAE method within an interval for each parameter. The PI control was chosen because the performance difference was not significant and the derivative part could turn the error bigger due to the way the system was modelled. The process variable was controlled and the effects on the variation head loss in one of the system branches was observed. The models have many simple parts; each one can be replaced by a more complex one if necessary. Thus, the present modeling may be used as guide for future improvements.
39

Espectroscopia do núcleo 23Mg acima do limiar de decaimento de prótons com interesse para astrofísica nuclear / Spectroscopy of 23Mg nucleus above the proton threshold of interest to nuclear astrophysics

Lara, Alessandro Luiz de 05 November 2018 (has links)
O conhecimento das reações nucleares que ocorrem no interior das estrelas permite estudar como será a evolução destes astros e as relações de abundância entre os isótopos de alguns elementos. Em alguns casos, a detecção de elementos traços pode ser útil para inferir a ocorrência de eventos explosivos, como novas e supernovas. Um destes elementos é o 22Na, cuja abundância depende da reação de captura de próton 22Na(p, ?)23Mg. Assim, o estudo dos estados de ressonância do 23Mg, é importante para compreender o mecanismo de reação e determinar a abundância do 22Na. O núcleo de 23Mg ainda participa do ciclo NeNa na fase AGB da evolução de estrelas de massa média. Com essa motivação propomos o estudo espectroscópico do núcleo 23Mg por meio da reação de transferência 24Mg(3He, 4He)23Mg, cujos dados experimentais foram obtidos no laboratório Tandem-Orsay (França), com o uso de um feixe de 3He de 25 MeV. As ressonâncias de interesse do núcleo 23Mg estudadas nesse trabalho estão compreendidas na faixa de energia de excitação 7.5 MeV a 9.5 MeV. Os estados de ressonância do 23Mg foram populados com a interação do feixe com o alvo de natMg, e as partículas de 4He foram analisadas com o espectrógrafo Split-pole. Os espectros de posição das partículas de 4He foram então calibrados em rigidez magnética, por meio de um polinômio de segunda ordem. Após a calibração os espectros de rigidez magnética foram transformados em espectros de energia de excitação. Nesses espectros pudemos identificar e estudar a presença de contaminantes. Vários estados abaixo e alguns estados acima do limiar de decaimento foram observados e identificados. Dentre os estados acima do limiar estão os estados: 7.586, 7.648, (7.782 e 7.786), 7.855, 8.076, 8.163, 8.420, 8.453, 8.943 e 8.990 MeV do 23Mg. Sendo que apenas os estados 7.586 e 8.163 tem o spin J=5/2+ estabelecido. Ao final apresentamos uma discussã / The knowledge of the nuclear reactions that take place inside the stars allows to study how the evolution of this star will be and the relations of abundance between the isotopes of some elements. In some cases the detection of trace elements can be useful to infer about the occurrence of explosive events, as novae and the supernovae. One of these elements is the 22Na, whose abundance depends on the proton capture reaction 22Na(p, ?)23Mg. The gamma radiation photon with energy 1.275 MeV emitted by 22Na may be a novae type event indicator. Thus, the study of the resonance states of 23Mg is important to understand the mechanism of reaction and determine the 22Na abundance. The nucleus of 23Mg still participate in the cycle NeNa in the AGB phase of the evolution of average stars. With this motivation, we propose to study the spectroscopy of the 23Mg by the 24Mg(3He, 4He)23Mg neutron transfer reaction, whose experimental data were obtained in the Tandem-Orsay facility (France), using the 3He beam of energy 25 MeV. The resonances of interest for this work are in the range of 7.5 MeV up to 9.5 MeV, above the decay threshold for protons. The resonance states of 23Mg were obtained with the interaction of the beam with the natMg target, and the 4He particles were analyzed in a Split-pole spectrograph. The position spectra were then calibrated in magnetic rigidity by means of a second-order polynomial function. The effects of the contaminants were analyzed by converting the spectra into excitation energy, in which it was possible to separate the states 7.586, 7.648, (7.782 e 7.786), 7.855, 8.076, 8.163, 8.420, 8.453, 8.943 e 8.990 MeV of 23Mg. Finally we present a qualitative discussion of the angular distribution for some states and we discuss the possibilities for the future.
40

Split intransitivity : thematic roles, case and agreement

Baker, James Samuel January 2018 (has links)
This dissertation is an extended argument for the syntactic structure proposed in (1), referred to as the 'VICTR Hierarchy' after the initials of the five functional heads it comprises: (1) [VolitionP Volition [InitiationP Initiation [ConsecutionP Consecution [TransitionP Transition [ResultP Result [VP ] ] ] ] ] ] The VICTR Hierarchy is a hierarchy of functional heads corresponding to the part of the clause generally known in the minimalist literature as `vP' or the `thematic domain'. Nominal arguments are merged in the specifiers of one or more of these heads and receive their thematic interpretations on the basis of their merged positions. Evidence for a model of thematic roles and syntactic argument structure based in the VICTR Hierarchy is presented for a range of domains, with a focus on 'split intransitivity'. Split intransitivity is explored initially in regard to English, with close consideration of a range of split intransitive diagnostics (e.g. 'out'-prefixation, the resultative construction); a VICTR account of these patterns is presented. A VICTR account of auxiliary selection patterns in Western European languages is also given. This is followed by analysis of split intransitive case and agreement systems. A formal account of the case and agreement patterns in these languages based in the VICTR hierarchy is presented, derived in part from the inherent case theory of ergativity (Legate 2002, Aldridge 2004 and others) and drawing on a detailed typology. The dissertation then proceeds to detailed analysis of the semantic basis of split intransitive alignment in two languages, Basque and Georgian. Other split intransitive behaviours in these languages are also considered in VICTR terms. Throughout, the VICTR approach is compared to other approaches to split intransitivity following Perlmutter's (1978) Unaccusative Hypothesis. The VICTR Hierarchy is also compared to the similar proposal of Ramchand (2008). It is argued that the VICTR Hierarchy accounts more readily than these other approaches for the particular classes of verbs identified by split intransitivity diagnostics in the languages considered, and also for cross-linguistic variation in split intransitive behaviours. Much support, with some caveats, is also found in the data considered for the applicability of Sorace's (2000) Auxiliary Selection Hierarchy (ASH) to a range of split intransitive phenomena cross-linguistically. Together with acquisitional considerations, the VICTR features are argued to allow for a formalisation of the patterns described by the ASH.

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