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Sheridan, Richard Stuart. „Optimisation of HDDR processing parameters of sintered NDFEB magnets“. Thesis, University of Birmingham, 2014. http://etheses.bham.ac.uk//id/eprint/4929/.
Der volle Inhalt der QuelleFengming, Li. „Modeling and Control of Algae Harvesting, Dewatering and Drying (HDD) Systems“. Case Western Reserve University School of Graduate Studies / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=case1333480231.
Der volle Inhalt der QuelleSilva, Suelanny Carvalho da. „Nanocompósitos à base de Pr2Fe14B/ α - Fe para aplicações térmicas“. Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/85/85134/tde-29042013-101915/.
Der volle Inhalt der QuelleIn this work, PrxFe94-xB6 (x = 6, 8, 10 and 12) nanostructured powders were prepared by a combination of hydrogenation, disproportionation, desorption and recombination (HDDR) process with high energy milling applied to the mixture of an as-cast alloy (Pr14Fe80B6) and α-Fe. The produced nanoparticles showed magnetic properties comparable to those reported in hyperthermia studies. The optimal time to obtain the magnetic nanoparticles is 5 hours (at 900 rpm). It was verified that longer milling times cause an increase in carbon percentage on the particles. The carbon is derived from oleic acid added as a surfactant in the milling step. The nanocomposites exhibit coercive force ranging from 80 Oe (6.5 kAm-1) to 170 Oe (13.5 kAm-1) and magnetic moments in the range of 81 129 Am2kg-1. From the x-ray diffraction analyses, only two phases were found in all samples: α-Fe and the magnetic phase Pr2Fe14B. Individual nanoparticles with diameter of about 20 nm were verified. The samples studied presented heating when exposed to an alternating magnetic field (f = 222 kHz e Hmax ~3.7 kAm-1) comparable to reported in literature. Temperature variations (ΔT) of the powders were: 51 K for Pr6Fe88B6, 41 K for Pr8Fe86B6, 38 K for Pr10Fe84B6 and T = 34 K for Pr12Fe82B6. The specific absorption rates (SARs) of the powders were 201 Wkg-1 for Pr6Fe88B6 composition, 158 Wkg-1 on the composition Pr8Fe86B6, and 114 Wkg-1 for Pr10Fe84B6 and Pr12Fe82B6 compositions.
Sun, Peng. „HPV-16 E6, hDlg and Connexin 43 in cervical carcinogenesis“. Thesis, University of Glasgow, 2005. http://theses.gla.ac.uk/5003/.
Der volle Inhalt der QuelleFujita, Akira. „A study on magnetic anisotropy induced in the HDDR process“. Thesis, University of Birmingham, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.343855.
Der volle Inhalt der QuelleShivane, Chetan. „Environment-friendly anti-corrosion 'Superprimers' for HDG“. Cincinnati, Ohio : University of Cincinnati, 2006. http://www.ohiolink.edu/etd/view.cgi?acc%5Fnum=ucin1140205616.
Der volle Inhalt der QuelleTitle from electronic thesis title page (viewed Apr. 20, 2006). Includes abstract. Keywords: Superprimer,Corrosion, Coatings, Silanes, primers, HDG Includes bibliographical references.
SHIVANE, CHETAN. „ENVIRONMENT-FRIENDLY ANTI-CORROSION 'SUPERPRIMERS' FOR HDG“. University of Cincinnati / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1140205616.
Der volle Inhalt der QuelleCannesan, Nicolas. „The production and characterisation of anisotropic HDDR (Pr,Nd)FeB-based powders“. Thesis, University of Birmingham, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.402527.
Der volle Inhalt der QuelleKonigsberg, Paul C. (Paul Carey) 1976. „Acquisition behavior for a HDD interpolative timing recovery system“. Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/80089.
Der volle Inhalt der QuelleIncludes bibliographical references (leaf 20).
by Paul Carey Konigsberg.
S.B.and S.Eng.
Engerroff, Juliano Assis Baron. „Obtenção via HDDR de pós nanocristalinos anisotrópicos à base de Nd-Fe-B“. reponame:Repositório Institucional da UFSC, 2015. https://repositorio.ufsc.br/xmlui/handle/123456789/169331.
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O mercado de ímãs permanentes para aplicações de alto desempenho é hoje dominado pelos ímãs à base de terras raras (TR), como os ímãs de Nd-Fe-B. Neste contexto, uma das técnicas mais promissoras atualmente para obtenção de pós para ímãs compósitos é o processo d-HDDR (hidrogenação-desproporção-dessorção-recombinação, d = dinâmico), tratamento este realizado a alta temperatura sob atmosfera de hidrogênio a fim de promover o endurecimento magnético pelo refinamento da microestrutura, além de induzir textura magnética que, por consequência, maximiza o valor de produto de energia máximo. O presente trabalho tem como foco o estudo do processo d-HDDR aplicado a uma liga à base de Nd-Fe-B da classe comercial N42 para obtenção de pós nanocristalinos próprios para preparação de ímãs anisotrópicos. Sendo assim, elaborou-se um ciclo próprio de d-HDDR de referência e, a partir do mesmo, determinou-se as influências das seguintes variáveis: tempo de patamar para desproporção; tempo de patamar para recombinação final e temperatura de patamar para desproporção e recombinação. A caracterização magnética das amostras se deu por meio de um histeresígrafo. Já a microestrutura foi caracterizada via difração de raios X e microscopia eletrônica de varredura com emissão de campo. Os resultados mostraram que o processo d-HDDR estudado foi efetivo para obtenção de pós nanocristalinos com tamanho de grão de aproximadamente 300 nm e com grau de alinhamento de 80%. Para os intervalos de tempo de patamar de desproporção analisados, não há mudanças significativas dos valores de propriedades magnéticas quando comparados aos valores de referência, mantendo-se em Br ? 1,07 T, Hcj ? 700 kA/m e (BH)max ? 75 kJ/m³. Já para diferentes intervalos de tempo de patamar para recombinação final, ocorrem mudanças significativas dos valores de propriedades magnéticas, havendo um patamar de valores máximos em intervalos próximos ao de referência, onde Br ? 1,1 T, Hcj ? 700 kA/m e (BH)max ? 85 kJ/m³. Considerando as diferentes temperaturas de patamar para desproporção e recombinação avaliadas, os máximos valores de propriedades magnéticas atingidos foram: Br ? 1,05 T, Hcj ? 700 kA/m e (BH)max ? 80 kJ/m³.
Abstract : Rare earth-based magnets, e.g. Nd-Fe-B, now dominate the market of permanent magnets used for high performance applications. In this regard, one of the most promising techniques is currently the so called d-HDDR process (hydrogenation-disproportionation-desorption-recombination, d = dynamic), which includes a set of high temperature treatments under hydrogen atmosphere, in order to ensure magnetic hardening by microestrutural refinement and induce magnetic texture, whose consequently maximize maximum energy product value. This work focuses on the study of d-HDDR process applied to Nd-Fe-B-based alloy of N42 commercial class in order to obtain nanocrystalline powders, proper for anisotropic magnets fabrication. Therefore, it was prepared a proprietary d-HDDR cycle in which the following variables were studied: holding time for disproportionation; holding time for final recombination and disproportionation-recombination temperature. Magnetic characterization of the samples was carried out by means of a histeresigraph, whereas the formed phases were characterized via X-ray diffraction and the microstructure by scanning electron microscopy. Results showed that d-HDDR process was effective for obtaining anisotropic powders with grain size of approximately 300 nm and alignment degree of 80%. For the studied interval of holding time for disproportionation, no significant change of the magnetic values occurred if compared to the reference cycle, with values of Br ? 1.07 T, Hcj ? 700 kA/m e (BH)max ? 75 kJ/m³. However, for different time intervals in final recombination, there are significant changes in the values of magnetic properties, with a plateau of maximum values near the reference range, in which Br ? 1.1 T, Hcj ? 700 kA/m e (BH)max ? 85 kJ/m³. Regarding the different studied temperatures for disproportionation and recombination, the maximum values of magnetic properties achieved were Br ? 1.05 T, Hcj ? 700 kA/m and (BH)max ? 80 kJ/m³.
Perugi, Fabien. „HDLG, un médiateur cellulaire de l'assemblage des rétrovirus VIH-1 et HTLV-1“. Paris 7, 2008. http://www.theses.fr/2008PA077020.
Der volle Inhalt der QuelleUnderstanding the various steps leading to the production of viral particles is, nowadays, a major axis of research in retrovirology. In order to find a cellular protein able to link Gag and envelope (Env) precursors of HTLV-1, we performed a two hybrid screen. First of ail, our team identified hDIg as a cellular partner of the cytoplasmic tail of the HTLV-1 envelope glycoproteins. Our study demonstrated that this interaction is needed for the late steps of membrane fusion during cell to cell transmission of HTLV-1. We also evidenced an interaction between Gag and hDIg in Env-enriched areas of the plasma membrane which suggests that hDIg could be a linker for Gag and Env precursors assembly. Based on these findings and the strong homologies of structure and functions between the domains of Gag precursors of different retroviruses, we focused our study on the role of hDIg in the viral cycle of HIV-1. In this case, hDIg seems to be a protein that negatively regulates the infectivity of HIV-1 particles, by retaining Gag proteins at the plasma membrane. We suggest that hDIg could prevent Gag precursors from reaching a trafficking pathway by optimizing the incorporation of Env into virions. Thus, hDIg would be the first restriction factor of the late steps of the HIV-1 lifecycle
Geier, Florian. „The differences between SSD and HDD technology regarding forensic investigations“. Thesis, Linnéuniversitetet, Institutionen för datavetenskap (DV), 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-44921.
Der volle Inhalt der QuelleMagnusson, Fredrik. „Implementing a Backup-Scheme with the 3-2-1 Strategy : A Comparison of the Active Solution with a New Implemented 3-2-1 Backup-Scheme“. Thesis, Mittuniversitetet, Avdelningen för informationssystem och -teknologi, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-34347.
Der volle Inhalt der QuelleThis report handles the theory behind probability, backups and hard drives. Based on this, a backup-scheme is implemented with the help of NASes, to replace the current solution. The need for a more secure, more reliable and a solution that is expandable due to the quick growth of the company, was put forward together with a budget to provide a solution suited after the effective need. This scheme is based upon theory in combination with third-party results and for this specific case has the budget, provided by the company, as a starting point to accomplish a sustainable, expandable and automated backup. Furthermore, this report implements this solution into the existing infrastructure where automation and simple handling of backups and why a 3-2-1 solution will be used. The report finds that after the new solution is implemented there is significantly less risk of data failure as well as an overall increase in speed and automation. Finally, with the help of standardized tools this report lay a decent groundwork for others to use in their implementation or to dig deeper into the world of reliability.
Amorim, Felipe Guedes, und (92) 99537-5427. „Caracterização da infecção pelos vírus da hepatite B e D em plasma e tecido hepático de portadores crônicos“. Universidade Federal do Amazonas, 2018. https://tede.ufam.edu.br/handle/tede/6722.
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Fundação de Amparo a Pesquisa do Amazonas (FAPEAM)
The hepatitis B virus (HBV) is responsible for a serious global public health problem, and the problem becomes even greater when coinfection or superinfection of D virus (HDV). It is estimated that of the 240 million people worldwide with chronic HBV infection, 15 million are carriers of HDV infection. Some regions of the Amazon Basin, particularly the State of Amazonas, are considered endemic areas of infection by these viruses. HDV is classified into eight different types (HDV-1-HDV-8) and HBV in ten (A-J). Thus, this research aims to characterize the genotypes of hepatitis B and D virus in plasma and hepatic tissue and to investigate possible association of genotypes with the evolution of the disease. Plasma and hepatic tissue samples from chronic HBsAg-reactive patients coinfected with HDV were analyzed. Plasma VHD viral load was quantified by real-time PCR; amplification of HBV DNA and VHD RNA by conventional PCR; direct sequencing of both viruses; phylogenetic analysis and research of resistance mutations in rt HBV. As a result, a total of 30 reactive HBsAg and Total Anti-HD patients, all from the State of Amazonas, were included in the study. Of these, 9/30 had both plasma and hepatic tissue samples. RNA-VHD was detected in 13/30 (46.67%) and HBV DNA in 11/30 (36.67%). Of the 09 plasma and hepatic tissue samples, VHD-RNA was detected in 2/9 (22.27%) and HBV DNA in 8/9 (88.89%). Of the 30 plasma samples submitted to VHD RNA quantification, viral load was obtained in 13/30 (46.67%). We also analyzed the 9 samples of hepatic tissue, obtaining viral load in 2/9 (22.27%). In the phylogenetic analysis, all the Delta sequences clustered in the clade VHD-3, already those of HBV, the genotypes A 15/19 (78%), D 2/19 (11%) and F 2/19 (11%). Concerning the search for antiviral resistance mutations in rt-HBV, 3/11 (27%) and 5/08 (62%) sequences isolated from plasma and hepatic tissue, respectively, showed resistance mutations. Conclusions: three HBV genotypes A, D and F were detected, independent of the source material; all extracted from delta were exclusively VHD-3; the viral load of the delta virus was higher in those extracted from hepatic tissue; a high percentage of mutations in the HBV polymerase region was detected, especially in isolated hepatic tissue sequences. Finally, the profile of the HBV and VHD genotypes found in the study reflects the same pattern found in the region by other authors.
O vírus da hepatite B (VHB) é responsável por um grave problema de saúde pública mundial, sendo que o problema torna-se ainda maior quando ocorre coinfecção ou superinfecção com o vírus D (VHD). Estima-se que das 240 milhões de pessoas no mundo portadoras crônicas de infecção pelo VHB, 15 milhões são portadoras de infecção pelo VHD. Algumas regiões da Bacia Amazônica, particularmente o Estado do Amazonas são consideradas áreas endêmicas de infecção por esses vírus. O VHD é classificado em oito diferentes tipos (VHD-1-VHD-8) e o VHB em dez (A-J). Sendo assim, esta pesquisa tem como objetivo, caracterizar os genótipos do vírus da hepatite B e D no plasma e tecido hepático e investigar possível associação dos genótipos com a evolução da doença. Foram analisadas amostras de plasma e de tecido hepático de pacientes portadores crônicos HBsAg reativos coinfectados com o VHD. Foi realizada a quantificação da carga viral do VHD no plasma por PCR em tempo real; amplificação do DNA-VHB e RNA-VHD por PCR convencional; sequenciamento direto de ambos os vírus; análise filogenética e pesquisa de mutações de resistência na rt do VHB. Como resultados, foram incluídos no estudo um total de 30 pacientes HBsAg e Anti-HD Total reativos, todos procedentes do Estado do Amazonas. Destes, 9/30 tinham simultaneamente amostras de plasma e tecido hepático. O RNA-VHD foi detectado em 13/30 (46,67%) e o DNA-VHB em 11/30 (36,67%). Das 09 amostras de plasma e tecido hepático o RNA-VHD foi detectado em 02/9 (22,27%) e o DNA-VHB em 08/9 (88,89%). Das 30 amostras de plasma submetidas a quantificação do RNA VHD, obteve-se a carga viral de 13/30 (46,67%). Também analisamos as 9 mostras de tecido hepático, obtendo-se a carga viral em 2/9 (22,27%). Na análise filogenética, todas as sequências de Delta agruparam-se no clado VHD3, já as de VHB, foram identificados os genótipos A 15/19 (78%), D 2/19 (11%) e F 2/19 (11%). Em relação à pesquisa de mutações de resistência à antivirais na rt-VHB, verificou-se que 3/11 (27%) e 05/08 (62%) sequencias isoladas do plasma e tecido hepático, respectivamente, apresentavam mutações de resistência. Conclusões: foi detectado três genótipos do VHB A, D e F, independente do material de origem; todos os extraídos de delta foram exclusivamente VHD-3; a carga viral do vírus delta, foi maior nos extraídos de tecido hepático; quanto ao perfil de mutações de resistência, foi detectado um percentual elevado de mutações na região da polimerase do VHB, principalmente nas sequências isoladas do tecido hepático. Por fim, o perfil dos genótipos do VHB e VHD encontrados no estudo reflete o mesmo padrão encontrado na região por outros autores
Freire, Thamires Batello. „Desenvolvimento e avaliação da segurança e eficácia de nanoemulsão com cafeína com ação na HDLG“. Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/9/9139/tde-01062017-162648/.
Der volle Inhalt der QuelleGinoide Hydrolipodystrophy (HDLG), commonly known as cellulite, occurs in 80-90% of the female population after the puberty period, comes from a metabolic modification in cutaneous adipose tissue. Caffeine, in turn, promotes a lipolytic action and is widely used by formulators. This project obtained nanoemulsion containing as main ingredients surfactants (Oleth-3; Oleth-20) and caffeine by emulsification method by (TIF). Emulsions were developed, with F3 being chosen, the most translucent with clearing-boundary Temperature (Tcb) of approximately 80 °C and phase inversion temperature (TIF) of 85 °C. In the Preliminary Stability Test (PET), the nanoemulsion showed no changes in its organoleptic characteristics, except in the thermal stress test in which phase separation occurred above 70 °C. In the Normal Stability Test (TEN) the condition of 45.0 ± 2.0 °C showed instability, in the other temperature values the nanoemulsions were classified as normal. The pH values for the conditions of 25.0 ± 2.0 °C and 5.0 ± 2.0 °C declined over the course of 90 days, 13.7 and 2.0% respectively. These values were evaluated by ANOVA, followed by Tukey\'s test, suggesting that F3 storage should be refrigerated. The polydispersion indices showed reduced deviation of 0.1. Indicating the presence of droplets with high polydispersity and monodisperse character. The droplet size in the condition of 5.0 ± 2.0 °C had size and percentage of variation lower than the condition 25.0 ± 2.0 ° C. The zeta potential at t0 was -3.9. The percentage of Transmittance at t0 and with t90 days of TEN presented values of 48.7 and 6.5% respectively, indicating a loss of transparency over time. Evaluated constant of Ostwald, in the refrigerator condition was the most favorable for stability. In the Raman spectroscopy assay the caffeine spectrum was compared in solution at various pH values and the band displacement and its protonation were not observed. The caffeine bands found in F3 were compatible with those found in the caffeine solution (1337, 652.5 and 558.2 cm -1). There was no interaction of caffeine anhydrous with Caprylic/Capric Triglyceride oil (TAAC) nor with Oleth-3 and Oleth-20 surfactants. The analytical validation of the method was linear, precise and accurate. There was a reduction of the caffeine concentration over the TEN time, in the condition of 5.0 ± 2.0 °C (15.1%). The caffeine association efficiency in the droplet was 4.8%. In the safety assay of using nanoemulsion in vitro HET CAM - Hen\'s Egg Test - Chorioallantoic Membrane, the result of 1.4 ranked the nanoemulsion F3 as slightly irritating. In the natural membrane cutaneous permeation test (human skin) permeate concentrations did not exceed the saturation concentration of the (PBS) Phosfate Saline (48.96 µg/3 mL). The caffeine solution permeated more than the nanoemulsion with caffeine F3, but the nanoemulsion visually and sensorially improved the caffeine precipitation.
Nehmetallah, Georges. „Méthodes Galerkin discontinues hybrides couplées à des schémas de type explicite/implicite pour les équations de Maxwell instationnaires“. Thesis, Université Côte d'Azur, 2020. http://www.theses.fr/2020COAZ4098.
Der volle Inhalt der QuelleIn this thesis, we study and develop different families of time integration schemes combined with a hybrid discontinuous Galerkin (HDG) discretization in space for Maxwell’s equations. After presenting a review of HDG methods for Poisson equation, time-harmonic Maxwell’s equations and for the time-domain Maxwell’s equations with a fully implicit time discretization in the first part, we construct a fully explicit HDGTD method for the 3D time-domain Maxwell’s equations in the second part. This HDGTD method is high order accurate in both space and time and can be seen as a generalization of the classical DGTD scheme based on upwind fluxes. In particular, it coincides with the latter scheme for a particular choice of the stabilization parameter introduced in the definition of numerical traces in the HDG framework. We provide numerical results aiming at assessing its numerical convergence properties. Then we propose a novel postprocessing technique for the latter method that we couple with an explicit Runge-Kutta time-marching scheme. The postprocessed electromagnetic field converges one order faster than the unpostprocessed solution in the H(curl) -norm. The proposed approach is local, in the sense that the enhanced solution is computed independently in each cell of the computational mesh, and at each time step of interest. As a result, it is inexpensive to compute, especially if the region of interest is localized, either in time or space. We present several numerical experiments that highlight the superconvergence properties of the postprocessed electromagnetic fields. Pursuing our aim, we propose a methodology to construct hybrid explicit/implicit (IMEX) HDGTD methods for Maxwell’s equations in the last part. We present the IMEX HDGTD methods obtained from dividing the semi-discrete formulation into coarse and fine parts and then applying three different IMEX time-marching of three different orders (less or equal to 3). We present numerical results for various test cases. An L shape domain where we have a singularity in the solution, a heterogeneous domain where we have an important variation of the wave speed, and a crystal photonic device where the spheres made of silicium are too close to each other. In these cases, the locally refined meshes are a must for the accuracy of the approximated solution and the and the obtained numerical results demonstrate that our methods are efficient in terms of accuracy and CPU time metrics.obtained numerical results demonstrate that our methods are efficient in terms of accuracy and CPU time metrics
Engerroff, Juliano Assis Baron. „Obtenção via HDDR de pós nanocristalinos anisotrópicos à base de Nd-Fe-B“. reponame:Repositório Institucional da UFSC, 2015. https://repositorio.ufsc.br/xmlui/handle/123456789/162585.
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O mercado de Ãmãs permanentes para aplicações de alto desempenho é hoje dominado pelos Ãmãs à base de terras raras (TR), como os Ãmãs de Nd-Fe-B. Neste contexto, uma das técnicas mais promissoras atualmente para obtenção de pós para Ãmãs compósitos é o processo d-HDDR (hidrogenação-desproporção-dessorção-recombinação, d = dinâmico), tratamento este realizado a alta temperatura sob atmosfera de hidrogênio a fim de promover o endurecimento magnético pelo refinamento da microestrutura, além de induzir textura magnética que, por consequência, maximiza o valor de produto de energia máximo. O presente trabalho tem como foco o estudo do processo d-HDDR aplicado a uma liga à base de Nd-Fe-B da classe comercial N42 para obtenção de pós nanocristalinos próprios para preparação de Ãmãs anisotrópicos. Sendo assim, elaborou-se um ciclo próprio de d-HDDR de referência e, a partir do mesmo, determinou-se as influências das seguintes variáveis: tempo de patamar para desproporção; tempo de patamar para recombinação final e temperatura de patamar para desproporção e recombinação. A caracterização magnética das amostras se deu por meio de um histeresÃgrafo. Já a microestrutura foi caracterizada via difração de raios X e microscopia eletrônica de varredura com emissão de campo. Os resultados mostraram que o processo d-HDDR estudado foi efetivo para obtenção de pós nanocristalinos com tamanho de grão de aproximadamente 300 nm e com grau de alinhamento de 80%. Para os intervalos de tempo de patamar de desproporção analisados, não há mudanças significativas dos valores de propriedades magnéticas quando comparados aos valores de referência, mantendo-se em Br ? 1,07 T, Hcj ? 700 kA/m e (BH)max ? 75 kJ/m³. Já para diferentes intervalos de tempo de patamar para recombinação final, ocorrem mudanças significativas dos valores de propriedades magnéticas, havendo um patamar de valores máximos em intervalos próximos ao de referência, onde Br ? 1,1 T, Hcj ? 700 kA/m e (BH)max ? 85 kJ/m³. Considerando as diferentes temperaturas de patamar para desproporção e recombinação avaliadas, os máximos valores de propriedades magnéticas atingidos foram: Br ? 1,05 T, Hcj ? 700 kA/m e (BH)max ? 80 kJ/m³.
Abstract : Rare earth-based magnets, e.g. Nd-Fe-B, now dominate the market of permanent magnets used for high performance applications. In this regard, one of the most promising techniques is currently the so called d-HDDR process (hydrogenation-disproportionation-desorption-recombination, d = dynamic), which includes a set of high temperature treatments under hydrogen atmosphere, in order to ensure magnetic hardening by microestrutural refinement and induce magnetic texture, whose consequently maximize maximum energy product value. This work focuses on the study of d-HDDR process applied to Nd-Fe-B-based alloy of N42 commercial class in order to obtain nanocrystalline powders, proper for anisotropic magnets fabrication. Therefore, it was prepared a proprietary d-HDDR cycle in which the following variables were studied: holding time for disproportionation; holding time for final recombination and disproportionation-recombination temperature. Magnetic characterization of the samples was carried out by means of a histeresigraph, whereas the formed phases were characterized via X-ray diffraction and the microstructure by scanning electron microscopy. Results showed that d-HDDR process was effective for obtaining anisotropic powders with grain size of approximately 300 nm and alignment degree of 80%. For the studied interval of holding time for disproportionation, no significant change of the magnetic values occurred if compared to the reference cycle, with values of Br ? 1.07 T, Hcj ? 700 kA/m e (BH)max ? 75 kJ/m³. However, for different time intervals in final recombination, there are significant changes in the values of magnetic properties, with a plateau of maximum values near the reference range, in which Br ? 1.1 T, Hcj ? 700 kA/m e (BH)max ? 85 kJ/m³. Regarding the different studied temperatures for disproportionation and recombination, the maximum values of magnetic properties achieved were Br ? 1.05 T, Hcj ? 700 kA/m and (BH)max ? 80 kJ/m³.
Bollero, Real Alberto. „Isotropic nanocrystalline (Nd,Pr)(Fe,Co)B permanent magnets“. Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2003. http://nbn-resolving.de/urn:nbn:de:swb:14-1069758225796-19366.
Der volle Inhalt der QuelleNanocrystalline permanent magnets present unusual magnetic properties because of surface/interface effects different from those of bulk or microcrystalline materials. This work presents results of a systematic investigation of the relationship between microstructure and magnetic properties in isotropic nanocrystalline (Nd,Pr)(Fe,Co)B permanent magnets. Highly coercive (Nd,Pr)FeB-type magnets have been produced using high energy ball milling and melt-spinning. The influence of small amounts of additives, Dy and Zr, and the substitution of Nd by Pr on the microstructural and magnetic properties are shown. An assessment of the hot deformation behaviour has been carried out. Intensive milling of an alloy with starting composition Pr9Nd3Dy1Fe72Co8B6.9Zr0.1 yields, after annealing treatment, nearly single-phase magnet powders with a maximum energy product (BH)max?î140kJm-3. Co has a beneficial effect on the intrinsic magnetic properties but also on the microstructure, with a mean grain size of 20nm. Intensive milling is used to produce high-performance nanocomposite magnets by blending this latter alloy with different fractions of soft magnetic alfa-Fe. Addition of 25wt.% alfa-Fe leads to a high (BH)max=178 kJm-3 due to an effective exchange-coupling between the hard and the soft magnetic phases. The intergrain interactions between the crystallites of the nanocomposite structure are analysed. Demagnetisation recoil loops of the nanocomposite magnets show relatively open minor loops due to the exchange-spring mechanism. Information about the intergrain interactions during demagnetisation are obtained by plotting the deviation of the demagnetising remanence from the Wohlfarth-model (¡§deltaJ-plot¡¨). Exchange-coupling phenomena are studied by analysing the evolution of the corresponding deltaJ values when varying (i) the alfa-Fe content, (ii) the annealing temperature, i.e. the grain size and (iii) the measurement temperature. Low temperature measurements do not reveal any sign of spin reorientation for these Pr-based nanocomposite magnets. The work concludes showing the possibility of using a mechanically activated gas-solid reaction to obtain an effective grain refined microstructure starting from stoichiometric Nd2(Fe1-xCox)14B alloys (x=0-1). These compounds were milled under enhanced hydrogen pressure and temperature leading to their disproportionation into NdH2+delta and bcc-(Fe,Co) (x=0-0.75) or fcc-Co (x=1). Grain sizes of recombined Nd2(Fe,Co)14B materials were found to be 40-50nm
Jamal, Fernando Galvanin. „Avaliação da precisão da declividade da técnica de perfuração direcional horizontal para instalações de redes de esgoto“. Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/18/18132/tde-10102008-091541/.
Der volle Inhalt der QuelleThe present work is focused on the horizontal directional drilling (HDD) method to install gravity sewers. The results of different techniques are described intending to meet the demands of gradient. Therefore, 4 experimental pilot bores were drilled simulating a section of those structures extending 30 m with HDPE pipelines of 125 mm external diameter. Those installations were engineered in the city of São Carlos, Brazil, in a clayey sand. For each of the 4 installations a distinct constructive process was adopted. Such characteristic was on account of the diameter of the selected reamer, the number of reamer steps and the vertical drills performed to relieve the pressure in the annular space, as well as the direct depth measurements of the pilot hole. After installing the pipes, altimetric measurements were performed inside them, hence enabling to quantitatively assess the obtained results. These results indicate the need to further refine the directional drilling technique for sanitary sewers. Yet it can be seen that the employed variations for each of the holes lead to an improved course of action with the observed results. Such improvement is perceived in the holes where the selected reamer had a smaller diameter, hence allowing for less displacement in the pipes final position. Also emphasized are the resulting benefits of the vertical drills that lead to less pressure in the annular space, as well as enabling altimetric measurements of the pilot hole position. Thus, it is presumed that with further experiments and technological developments the final objective is reached, meaning, putting into effect constant and low level gradient sewer networks. Tests for precision and accuracy assessment of the tracking system were also performed in each tube installed. The tracking system is responsible for providing information related to position and temperature of the drill head during the drilling operation. The steps for the development of a new HDD solution for sewer installation are presented. The idea is based on the application of a tensile force to an element external to the product, aiming at attaining a constant gradient. Equipments and procedures developed for this new technique are described.
Ferreira, Eliner Affonso. „Estudo das propriedades magnéticas e da microestrutura em ímãs permanentes à base de Pr-Fe-B-Co-Nb obtidos pelo processo HD e HDDR“. Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/85/85134/tde-18082009-162039/.
Der volle Inhalt der QuelleSintered magnets have been produced with powder obtained using the hydrogenation, disproportionation, desorption and recombination (HDDR) process. The HDDR process for the production of the sintered magnets has been adopted in an attempt to reduce the milling time and to investigate its effect on the magnetic properties and microstructure. Commercial cast ingot alloys based on the compositions Pr14Fe75.9CoxB6Nb0.1 (x = 0; 4; 8; 10; 12; 16) and Pr20.5Fe72.5B5Cu2.0 (sintering aid) have been employed in this investigation. The HDDR powder was used to produce sintered magnets with a mixture of these alloys (alloy main + sintering aid), in the following proportion: 80%wt of the main alloy and 20%wt of the sintering aid. Standard hydrogen decrepitation (HD) magnets have also been included in this work for a comparison (milling time: 20, 15, 10, 5 hours). The sintering temperature and time were kept constant for all magnets (1050ºC for 1 hour). The sintered magnet produced using the process HD exhibited the best remanence (1220 mT). It was prepared with the Pr14Fe67.9Co4B6Nb0.1 alloy using a milling time of 20 hours. The best intrinsic coercivity was achieved with the Pr14Fe67.9Co4B6Nb0.1 magnet in both processes, namely: 1020 mT for the HDDR process with 5 hours of milling time and 1190 mT for the HD process with 20 hours of milling time. The microstructures of the permanent magnets have been investigated by scanning electron microscopy and energy dispersive X-ray analysis.
SILVA, SUELANNY C. da. „Estudo da influência da temperatura nas propriedades magnéticas e na microestrutura nos imãs permanentes à base de Pr-Fe-B-Nb-Co obtidos com hidrogênio“. reponame:Repositório Institucional do IPEN, 2007. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11612.
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IPEN/D
Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP
Li, Hai. „Storage Physics and Noise Mechanism in Heat-Assisted Magnetic Recording“. Research Showcase @ CMU, 2016. http://repository.cmu.edu/dissertations/706.
Der volle Inhalt der QuelleXue, Dingchuan. „Electro-deposition of resin-modified water-based hydrophobic silane on HDG steel for corrosion protection“. University of Cincinnati / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1229010186.
Der volle Inhalt der QuelleOlivares, Nicole Michelle. „Accuracy of Wave Speeds Computed from the DPG and HDG Methods for Electromagnetic and Acoustic Waves“. PDXScholar, 2016. http://pdxscholar.library.pdx.edu/open_access_etds/2920.
Der volle Inhalt der QuelleSilva, Suelanny Carvalho da. „Estudo da influência da temperatura nas propriedades magnéticas e na microestrutura nos ímãs permanentes à base de Pr-Fe-B-Nb-Co obtidos com hidrogênio“. Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/85/85134/tde-24102011-104115/.
Der volle Inhalt der QuelleFine magnetic powders were produced using the hydrogenation disproportionation desorption and recombination (HDDR) process. The first stage in this work involved an investigation of the effect of the Co content and range of desorption/ recombination temperatures between 800 and 900°C with the purpose of optimizing the HDDR treatment for Pr14Fe80B6 and Pr14FebalCoxB6Nb0,1 (x= 0, 4, 8, 10, 12, 16) alloys. The cast alloys were annealed at 1100°C for 20 hours for homogenization. The processing temperature (desorption/ recombination) affected the microstructure and magnetic properties of the bonded magnets. The alloy with low cobalt content (4 at.%) required the highest reaction temperature (880°C) to yield anisotropic bonded magnets. The optimum temperature for alloys with 8 at.% Co and 10 at.% Co were 840°C and 820°C, respectively. Alloys with high cobalt content (12 at.% and 16 at.%) were processed at 840°C. The optimum desorption temperature for achieving high anisotropy for Pr14Fe80B6 and Pr14Fe79,9B6Nb0,1 was 820°C. The best remanence (862mT) was achieved with the Pr14Fe67,9B6Co12Nb0,1 magnet, processed at 840°C. Each alloy required an optimum reaction temperature and exhibited a particular microstructure according to the composition. The second stage of the work involved the characterization, for each temperature, of the Pr14Fe80B6 HDDR powder processed using X-ray diffraction analysis. The samples of the HDDR material were studied by synchrotron radiation powder diffraction using the Rietveld method for cell refinement, phase quantification and crystallite sizes determination. Scanning electron microscopy (SEM) has also been employed to reveal the morphology of the HDDR powder.
Santos, Patricia Brissi. „Efeitos da adição de surfactante e moagem de alta velocidade em pós magnéticos à base de Pr-Fe-B obtidos via HDDR“. Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/85/85134/tde-26012012-145626/.
Der volle Inhalt der QuelleThis work verified the effect caused by adding the surfactant in the high speed/energy milling in order to obtain Pr12Fe65.9Co16B6Nb0.1 magnetic nanopowders. The first part of this work involved the magnetic powder obtainment through the process of hydrogenation, disproportionation, desorption and recombination (HDDR). The pressure of H2 during the hydrogenation and disproportion steps was 930 mbar and the temperature of desorption and recombination was 840 ºC. Initially, the HDDR powders were subjected a highspeed milling process at 900 rpm, with quantity variations of the milling medium (cyclohexane) and without the addition of oleic acid. Then, the HDDR powders were subjected to the milling process with the addition of oleic acid and with milling time variations. After the milling process, heat treatments of the powder were carried out at 700 °C or 800 °C for 30 minutes in order to obtain the crystallization of the powder. By performing the procedures, it was verified that the milling efficiency improved with the addition of 6.6 ml of cyclohexane as the milling medium and with the addition of oleic acid. It was determined that for the surfactant additions of 0.02 ml to 0.05 ml, with a milling time of up to 360 minutes, powder agglomeration does not occur in the milling pot and the milling efficiency is higher than 90%. The second stage of this work involved the magnetic powders characterization obtained by using vibrating sample magnetometer, scanning electron microscopy, transmission electron microscopy and X-ray diffraction. Through the characterizations it was found that the powders magnetic properties improved when the addition of oleic acid in a high-speed /energy milling occurred. It was also verified that the α-Fe phase, present in the powder, shows a crystallite size decrease (from 35 nm to ~ 10 nm) when the time milling variation occurred; meanwhile, the crystallinity degree was lower in the Pr2Fe14B phase when the time milling variations was carried out.
SANTOS, PATRICIA B. „Efeitos da adição de surfactante e moagem de alta velocidade em pós magnéticos à base de Pr-Fe-B obtidos via HDDR“. reponame:Repositório Institucional do IPEN, 2011. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10044.
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IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
Carson, Hugh Alexander. „A priori analysis of global and local output error estimates for CG, DG and HDG finite element discretizations“. Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/105608.
Der volle Inhalt der QuelleCataloged from PDF version of thesis.
Includes bibliographical references (pages 103-105).
In this thesis, a priori convergence estimates are developed for outputs, output error estimates, and localizations of output error estimates for Galerkin finite element methods. Specifically, Continuous Galerkin (CG), Discontinuous Galerkin (DG), and Hybridized DG (HDG) methods are analyzed for the Poisson problem. A mixed formulation for DG output error estimation is proposed with improved convergence rates relative to the common approach utilizing statically condensed, p-dependent lifting operators. The HDG output error estimates are new and include the impact of stabilization. Comparisons to numerical results demonstrate (1) the sharpness of the estimates and (2) that the HDG estimates are approximately an order of magnitude more accurate than CG and DG.
by Hugh Alexander Carson.
S.M.
Elander, Per, und Dennis Thai. „Datalagring : en komparativ stude av datalagringslösningar“. Thesis, Högskolan Kristianstad, Sektionen för hälsa och samhälle, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:hkr:diva-15554.
Der volle Inhalt der QuelleFrydryszak, Andrzej. „Ocena zasadności budowy podziemnych przewodów metodą przewiertów sterowanych“. Rozprawa doktorska, [Nakł.aut.], 2005. http://dlibra.utp.edu.pl/Content/181.
Der volle Inhalt der QuelleOLIVEIRA, MARA C. L. de. „Preparacao de imas HDDR e ligas de PrFe-Co-B-Nb-M (M=Al,P,Cu,Ga e/ou Gd) e caracterizacao de suas propriedades magneticas e resistencia a corrosao“. reponame:Repositório Institucional do IPEN, 2009. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11783.
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IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
BARBOSA, LUZINETE P. „Estudo das propriedades e microestrutura de ímãs permanentes de Pr-Fe-B-(Co-Nb) preparados pelo processo de hidrogenação, desproporção, dessorção e recombinação (HDDR)“. reponame:Repositório Institucional do IPEN, 2005. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11280.
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Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
FERREIRA, ELINER A. „Estudo das propriedades magnéticas e da microestrutura em imãs permanentes à base de Pr-Fe-B-Co-Nd obtidos pelos processos HD e HDDR“. reponame:Repositório Institucional do IPEN, 2008. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11694.
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Hattasingh, Thanyaporn. „Bridging multinational companies intra-firm technology transfer and host country institutional factors- the cases of Thailand's HDD and IC sectors“. Thesis, University of Manchester, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.489635.
Der volle Inhalt der QuelleGalego, Eguiberto. „Estudo de ligas e ímãs preparados pelo processo hidrogenação, desproporção, dessorção e recombinação (HDDR) à base de Pr-Fe-B com adição de dopantes elementos de liga“. Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/85/85134/tde-09062008-153410/.
Der volle Inhalt der QuelleEstudo de Ligas e Ímãs Preparados pelo Processo Hidrogenação, Desproporção, Dessorção e Recombinação (HDDR) à Base de Pr-Fe-B com Adição de Dopantes e Elementos de Liga Eguiberto Galego RESUMO A adição de elementos dopantes e elementos de liga aos magnetos permanentes policristalinos à base de terras raras tem como objetivo a melhora das propriedades magnéticas. Neste trabalho estudou-se a adição de 0,1% at. dos elementos: Ti, V, Cr, Ni, Zr, Nb ou Mo na composição Pr14FebalCo16B6 ; as adições de 0,1 % at., 0,3 % at. e 0,5 % at. dos elementos Al, Si, P, Cu ou Ga na composição Pr14FebalCo16B6Nb0,1 ; e a variação de cobalto de 0 % at. até 16 % at. ao sistema Pr2Fe14-xCoxB. Através de processo HDDR (hidrogenação, desproporção, dessorção e recombinação) obteve-se pós com tamanho de grão da ordem de 200 a 300 nm para quase todas as composições estudadas. Os pós foram utilizados para a confecção de magnetos consolidados por cianoacrilato de baixa viscosidade. De maneira geral, a adição destes dopantes resultou no aumento ou diminuição da remanência e da coercividade intrínseca da liga quando comparadas com os valores obtidos para magnetos de referência sem adição de dopantes. Porém, não foram observadas correlações entre as composições estudadas quer quanto ao número atômico ou em relação à concentração do elemento adicionado. Os resultados obtidos com a adição de Al, Si, P, Ti, V, Cr, Ni, Cu, Ga, Zr ou Nb indicaram que alguns elementos atuam como substituintes do átomo de ferro na estrutura cristalina da fase magnética dura ou como modificador da microestrutura da liga. A determinação dos parâmetros da célula unitária, as posições atômicas, os sítios de substituição do ferro pelo cobalto (fator de ocupação) para a sistema Pr2Fe14-xCoxB foi realizada pelo refinamento dos padrões de pó obtidos por difração de raios X pelo método de Rietveld. Estes dados foram utilizados no cálculo das iii propriedades magnéticas por ab-initio com base na teoria do funcional densidade empregando o método LAPW (linearized augmented plane wave). A comparação dos resultados teórico e experimental apresentou forte concordância mostrando que este método é importante para o estudo da adição de dopantes ao sistema Pr-Fe-Co-B.
GALEGO, EGUIBERTO. „Estudo de ligas e imás preparados pelo processo hidrogenação, desproporção, dessorção e recombinação (HDDR) a base de Pr-Fe-B com adição de dopantes e elementos de liga“. reponame:Repositório Institucional do IPEN, 2008. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11611.
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Liesert, Silke. „Analyse physico-chimique des paramètres du développement d'une microstructure coercitive et anisotrope dans des poudres pour aimants liés puissants par application du procédé HDDR au néodyme-fer-bore“. Université Joseph Fourier (Grenoble), 1998. http://www.theses.fr/1998GRE10027.
Der volle Inhalt der QuelleRoßbach, Stefan [Verfasser]. „Untersuchungen zur Reduzierung der Zugkräfte beim Einziehen von Rohrleitungen mittels Schwingungstechnologie : ein innovativer Beitrag zur Reduzierung des Baurisikos bei HDD-Vorhaben / vorgelegt von Stefan Roßbach“. [Clausthal-Zellerfeld] : [Univ.-Bibliothek], 2008. http://d-nb.info/992514770/34.
Der volle Inhalt der QuelleSládek, Petr. „Disková pole RAID a jejich budoucnost v éře SSD“. Master's thesis, Vysoká škola ekonomická v Praze, 2012. http://www.nusl.cz/ntk/nusl-124667.
Der volle Inhalt der QuelleOliveira, Mara Cristina Lopes de. „Preparação de ímas HDDR e ligas de Pr-Fe-Co-B-Nb-M (M=Al, P, Cu, Ga e/ou Gd) e caracterização de suas propriedades magnéticas e resistência à corrosão“. Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/85/85134/tde-21092009-103331/.
Der volle Inhalt der QuelleHDDR process has attracted great interest for producing polymer- bonded rareearth based magnets. It presents commercial advantages when compared with conventional sintered magnets owing to easy and low cost manufacturing. With the development of anisotropic powders using praseodymium, the expectations about this process grow e also the need for studying new compositions and alloy additions. In this work the magnetic properties of polymer-bonded magnets prepared with PrFeB magnetic alloys using HDDR process have been studied. Pr14FebalCo16B6Nb0,1 was used as the reference alloy Phosphorus, copper, aluminium, galium and gadolynium additions have been performed to increase the magnetic properties of the reference alloy. The microstructural characterization of the magnets has been carried out through optical microscopy and SEM. The complex microsctructure influences the electrochemical behavior of the magnetic alloys. The literature about this subject is scarce. Thus, the corrosion resistance of the different alloys prepared during this work was evaluated using electrochemical impedance spectroscopy and potentiodynamic polarization curves. A correlation between the microstructural features and the electrochemical behavior of the alloys has been established. The results showed that phosphorus and aluminium additions up to 1.0wt% had a beneficial effect on the magnetic properties and corrosion resistance of the alloys. Copper additions, on the other hand, strongly diminished the magnetic properties of the reference alloy.
Ouarnoughi, Hamza. „Placement autonomique de machines virtuelles sur un système de stockage hybride dans un cloud IaaS“. Thesis, Brest, 2017. http://www.theses.fr/2017BRES0055/document.
Der volle Inhalt der QuelleIaaS cloud providers offer virtualized resources (CPU, storage, and network) as Virtual Machines(VM). The growth and highly competitive nature of this economy has compelled them to optimize the use of their data centers, in order to offer attractive services at a lower cost. In addition to investments related to infrastructure purchase and cost of use, energy efficiency is a major point of expenditure (2% of world consumption) and is constantly increasing. Its control represents a vital opportunity. From a technical point of view, the control of energy consumption is mainly based on consolidation approaches. These approaches, which exclusively take into account the CPU use of physical machines (PM) for the VM placement, present however many drawbacks. Indeed, recent studies have shown that storage systems and disk I/O represent a significant part of the data center energy consumption (between 14% and 40%).In this thesis we propose a new autonomic model for VM placement optimization based on MAPEK (Monitor, Analyze, Plan, Execute, Knowledge) whereby in addition to CPU, VM I/O and related storage systems are considered. Our first contribution proposes a multilevel VM I/O tracer which overcomes the limitations of existing I/O monitoring tools. In the Analyze step, the collected I/O traces are introduced in a cost model which takes into account the VM I/O profile, the storage system characteristics, and the cloud environment constraints. We also analyze the complementarity between the two main storage classes, resulting in a hybrid storage model exploiting the advantages of each. Indeed, Hard Disk Drives (HDD) represent energy-intensive and inefficient devices compared to compute units. However, their low cost per gigabyte and their long lifetime may constitute positive arguments. Unlike HDD, flash-based Solid-State Disks (SSD) are more efficient and consume less power, but their high cost per gigabyte and their short lifetime (compared to HDD) represent major constraints. The Plan phase has initially resulted in an extension of CloudSim to take into account VM I/O, the hybrid nature of the storage system, as well as the implementation of the previously proposed cost model. Secondly, we proposed several heuristics based on our cost model, integrated and evaluated using CloudSim. Finally, we showed that our contribution improves existing approaches of VM placement optimization by a factor of three
Boman, Joel, Markus Forsmark und Waldemar Schagerström. „Att presentera information i virtuell verklighet : En studie om var och hur information bör presenteras i virtuell verklighet vid användning av en fordonssimulator“. Thesis, Umeå universitet, Institutionen för informatik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-135586.
Der volle Inhalt der QuelleSherif, Ahmed. „Compact High-Order Accurate Scheme for Laminar Incompressible Two-Phase Flows“. Electronic Thesis or Diss., Ecole centrale de Nantes, 2023. http://www.theses.fr/2023ECDN0004.
Der volle Inhalt der QuelleThe objective of this thesis is to develop a high-order accurate method to solve the two-phase incompressible laminar flowproblem. Three main tasks are to be achieved. First, the method has to be energy-stable meaning that the divergence-free condition of the incompressible Navier-Stokes equation is satisfied everywhere in the computational domain. Second, the local discontinuities arising in the two-phase flow field have to be captured accurately. Third, the material interface betweenthe two fluids has to be represented accurately in each time step. In this work, a novel Hybridizable Discontinuous Galerkin (HDG) method is used for the spatial discretization. This hybrid method that belongs to the family of DG-FEM methods satisfies the divergence-free condition by introducing velocity and pressure trace variables of the same order plus a tailoredvelocity and pressure approximation inside the elements. Furthermore, the concepts of eXtended FEM (X-FEM) are used toapproximate discontinuities in the flow field by enriching the standard FEM approximation in elements where two fluids exist. Finally, the moving material interface between the twofluids is captured using the Level-Set method
Järrendal, Dan, und Dillekås Hans Tinggård. „Engreppsskördare med Head-Up Display“. Thesis, Linköping University, Department of Management and Engineering, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-8632.
Der volle Inhalt der QuelleArbetsbelastningen för föraren i en engreppsskördare är stor. Vid aptering måste föraren fokusera om blicken för att läsa av information från en Head-Down Display (HDD) samtidigt som föraren måste ha kontroll på kranspetsen vilket bidrar till arbetsbelastningen.
Syftet med projektet var att undersöka om arbetsbelastningen i engreppsskördare reducerades med Head-Up Display (HUD) under aptering. Först testades fyra HUD-gränssnitt i en simulator, därefter omarbetades gränssnitten innan de slutligen testades i en engreppsskördare i fält. En HUD-demonstrator utvecklades för detta ändamål.
Resultatet visade att arbetsbelastningen samt apteringstiderna minskade i simulatortestet med HUD jämfört med HDD. I fältstudien förblev arbetsbelastningen oförändrad men apteringstiderna minskade.
Att arbetsbelastningen minskade med HUD jämfört med HDD kan bero på att HUD är bättre än HDD och/eller att konceptens gränssnitt är effektivare att arbeta med än Valmet Maxi gränssnittet.
En HUD-demonstrator som fungerar under ljusstarka förhållanden och som tål påfrestningarna i en skördare borde utvecklas för vidare tester.
Wicht, Sebastian. „Atomar aufgelöste Strukturuntersuchungen für das Verständnis der magnetischen Eigenschaften von FePt-HAMR-Prototypmedien“. Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-216054.
Der volle Inhalt der QuelleHighly textured L10-ordered FePt+C-films are foreseen to become the next generation of magnetic data storage media. Therefore prototypes of such media (provided by HGST- A Western Digital Company) are structurally investigated down to the atomic level by HR-TEM and the observed results are correlated to the magnetic performance of the film. In a first study the occurrence of a strongly disturbed surface layer with a lattice spacing that corresponds to cementite is observed. Furthermore the individual particles are surrounded by a thin carbon layer that suppresses the deposition of further material and leads, therefore, to the formation of a second layer of particles. Without a contact to the seed layer these particles are randomly oriented and degrade the magnetic performance of the media. A further study reveals, that a selection of single-crystalline substrates with appropriate lattice mismatch to the L10-ordered unit cell can be applied to avoid the formation of in-plane oriented and L12-ordered crystals. Unfortunately, the required large mismatch results in a broadening of the texture of the [001]-axes of the individual grains. As electron holography studies reveal, the orientation of the magnetization of the individual grains can differ from the structural [001]-axis due to local fluctuations of the uniaxial anisotropy
Eklund, Rikard. „Presentation av taktisk information på bildskärm : Head-Up Display som stöd för tidsstyrd taxning med flygplan“. Thesis, KTH, Ergonomi, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-109317.
Der volle Inhalt der QuelleGürkan, Ceren. „Extended hybridizable discontinuous Galerkin method“. Doctoral thesis, Universitat Politècnica de Catalunya, 2018. http://hdl.handle.net/10803/664035.
Der volle Inhalt der QuelleEsta tesis propone una nueva técnica numérica: eXtended Hybridizable Discontinuous Galerkin (X-HDG), para resolver eficazmente problemas incluyendo fronteras en movimiento e interfaces. Su objetivo es superar las limitaciones de los métodos disponibles y mejorar los resultados, heredando propiedades del método Hybridizable Discontinuous Galerkin method (HDG), junto con una definición de interfaz explícita. X-HDG combina el método HDG con la filosofía de eXtended Finite Element method (X-FEM), con una descripción level-set de la interfaz, para obtener un método numérico hp convergente de orden superior sin ajuste de la malla a la interfaz o frontera. HDG supera a otros métodos de DG para los problemas implícitos con operadores autoadjuntos, debido a sus propiedades de hibridación y superconvergencia. El proceso de hibridación reduce drásticamente el número de grados de libertad en el problema discreto, similar a la condensación estática en el contexto de Continuous Galerkin (CG) de alto orden. Por otro lado, HDG se basa en una formulación mixta que, a diferencia de CG u otros métodos DG, es estable incluso cuando todas las variables (incógnitas primitivas y derivadas) se aproximan con polinomios del mismo grado k. Como resultado, la convergencia de orden k + 1 en la norma L2 se demuestra no sólo para la incógnita primal sino también para sus derivadas. Por lo tanto, un simple post-proceso elemento-a-elemento de las derivadas conduce a una aproximación superconvergente de las variables primales, con convergencia de orden k+2 en la norma L2. X-HDG hereda estas propiedades. Por otro lado, gracias a la descripción level-set de la interfaz, se evita caro remallado tratando las interfaces móviles. Este trabajo demuestra que X-HDG mantiene la convergencia óptima y la superconvergencia de HDG sin la necesidad de ajustar la malla a la interfaz. En los capítulos 2 y 3, se deduce e implementa el método X-HDG para resolver la ecuación de Laplace estacionaria en un dominio donde la interfaz separa un solo material del vacío y donde la interfaz separa dos materiales diferentes. La precisión y convergencia de X-HDG se prueba con ejemplos de soluciones fabricadas y se demuestra que X-HDG supera las propuestas anteriores mostrando convergencia óptima y superconvergencia de alto orden, junto con una reducción del tamaño del sistema gracias a su naturaleza híbrida, pero sin ajuste de la malla. En los capítulos 4 y 5, el método X-HDG se desarrolla e implementa para resolver el problema de interfaz de Stokes para interfaces vacías y bimateriales. Con X-HDG, de nuevo se muestra una convergencia de alto orden en mallas no adaptadas, para problemas de flujo incompresible. X-HDG para interfaces móviles se discute en el Capítulo 6. Se considera un problema térmico transitorio, donde el término dependiente del tiempo es discretizado usando el método de backward Euler. Un ejemplo de una interfaz circulas que se reduce, junto con el problema de Stefan de dos fases, se discute en la sección de ejemplos numéricos. Se demuestra que X-HDG ofrece un alto grado de convergencia óptima para problemas dependientes del tiempo. Además, con el problema de Stefan, usando un grado polinomial k, se demuestra una aproximación más exacta de la posición de la interfaz contra X-FEM, gracias a la aproximación del gradiente convergente k + 1 de X-HDG. Una vez más, se mejoran los resultados obtenidos por las propuestas anteriores
Semati, Massimiliano. „Soluzioni per il controllo delle testine di lettura/scrittura in hard disk drive magnetici“. Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amslaurea.unibo.it/11748/.
Der volle Inhalt der QuelleZhu, Xi. „High frequency CMOS integrated filters for computer hard disk drive and wireless communication systems“. Thesis, University of Hertfordshire, 2008. http://hdl.handle.net/2299/2069.
Der volle Inhalt der QuelleChiou, Wei-Rong, und 邱威融. „Miniemulsion copolymerization kinetics of HDDA/MMA and HDDA/styrene based microgel particles“. Thesis, 2016. http://ndltd.ncl.edu.tw/handle/84527723935489011168.
Der volle Inhalt der Quelle國立臺灣科技大學
化學工程系
104
The isothermal kinetic of miniemulsion copolymerization of 1,6- hexanediol diacrylate (HDDA) /styrene(ST) and 1,6-hexanediol diacryl- ate (HDDA) /methyl methacrylate (MMA) system was investigate by using differential scanning calorimeter ( DSC ) in this work . Miniemuslion and solution ( solvent such as toluene) copolymerization were carried out.The model-fitting method was linked with the model- free method was used to decide the relevant kinetic parameters. The reaction mechanisms for miniemulsion copolymerization and solution copolymerization were satisfactorily predicted by the nucleation Avrami - Erofeyev model [g(α)=-[ln(1-α) ]^(1/n) ] . The minieulsoin copolymer- izations were characterized by TEM、 FTIR.