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In the next decade, technology trends--smaller dimension, lower voltage, higher operating frequency--introduce new technical considerations and challenges for radiation effects in integrated circuits. Semiconductor based circuits and traditional dynamic random-access memories will malfunction when exposed to extreme environments, such as space and nuclear reactor. The mechanisms for radiation effect are mainly attributed to the radiation-induced charging of the oxide in a CMOS device. Spintronics is an emerging area of nanoscale electronics involving the detection and manipulation of electron spin. The magnetic tunnel junctions (MTJs), based on the intrinsic spin of the electron, can be used as the storage elements in non-volatile magnetoresistive random-access memories (MRAMs). In this effort, we study radiation tolerance of MTJs by exposing the devices in gamma and neutron radiation environment. Theoretical model for the radiation-induced defects is analyzed in this work. Experiments of the MgO-based MTJs under the conditions of pre- and post-radiation are concluded. MTJs were irradiated with gamma ray to a total dose of 10 Mrad. During the neutron irradiation, total epithermal neutron fluence up to 2.9��10�����/cm�� was obtained. The experimental results show that neither the electrical nor the magnetic properties of MTJs are affected by the radiation. / Graduation date: 2013 / Access restricted to OSU community at author's request from Sept. 11, 2012 - Sept. 11, 2014

A large multi-aperture telescope has the potential to reach the diffraction limit corresponding to its baseline. To do so, Adaptive Optics (AO) and beam combination are critical to good performance. Operation as an interferometer is a complicated mode for the telescope. The system now has much tighter tolerances and is difficult to align. The alignment process needs to be planned in multiple steps, and tolerance and sensitivity analysis needs to be performed for each step. Alignment tools can be prepared based on the resolution found in the sensitivity analysis in each step. Random fluctuation is another critical factor that reduces system performance. If noise sources near the telescope are characterized and identified, image quality can be improved by post-image processing. Measuring the outer scale of atmosphere is also helpful for understanding the system performance. The fringe tracking method in the Large Binocular Telescope Interferometer (LBTI) system provides optical path difference (OPD) variation, and the power spectral density of the OPD variation is used to estimate the size of the outer scale. However, this method is limited by the baseline of the LBTI by 5√3 B, where B is the baseline, and by this equation the outer scale size which is able to be estimated should be more than 125 m. AO simulation can provide an understanding of new AO system concepts and parameter variations before they are applied to the real system. In this dissertation study, we simulated an LBTI system with structural vibration of 10 Hz and 20 Hz and with various amplitudes. From the simulation, we learned that the slower bandwidth of piston-correcting systems allows stars as faint as ~13the magnitude to be observed. If there is significant vibration on the structure, the increased bandwidth will limit the phasing stars to 10~11th magnitudes. This demonstrates the limits of the LBTI system regarding structural vibration. An alternative phasing sensor for the LBTI system, the pseudo phasing sensor, can be used for more than 1000 m of outer scale of atmosphere. If the direct phasing sensor embedded in the LBTI system cannot be used for a very faint star, the pseudo phasing sensor, which approximately estimates the phase difference by AO wavefront sensor, can be useful for atmospheric conditions with estimated outer scale of about 1000 m. The analyses in this dissertation provide a partial guide for developing large-scale telescopes and astronomical instruments.

Because of a perceived increase in school related violence, a political reaction occurred in Missouri that led in 1997 to the Missouri Safe Schools Act. This new law significantly changed school disciplinary policy and allowed administrators to move large groups of students to alternative education programs, or expel them to the streets. The purpose of this qualitative study was to learn from students who attended at least one year in an alternative education program about their experiences. I interviewed 26 former students and another 14 former students entered into the conversation by posting their thoughts on a Facebook site for alumni of a specific alternative program. The 40 former students shared common stories that indicated their confusion, a misuse of power by the school district, and a lack of due process surrounding the events that led to their suspensions. At the same time, they shared many stories of relationships, kindnesses, and empathy that they experienced from the alternative school teachers and administrators. Results point to the need for families to educate themselves (and sometimes resist) arbitrary decisions made by school personnel, and the importance of teacher and administrator selection for alternative school programs.

Made available in DSpace on 2014-06-11T19:35:00Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-05-15Bitstream added on 2014-06-13T20:45:44Z : No. of bitstreams: 1 rocha_kcg_dr_botfca.pdf: 895303 bytes, checksum: cd87505fac20f9742a811226a9c1fc11 (MD5) / Considerando o aumento de begomovírus e mosca-branca no campo o presente trabalho teve como objetivos a detecção, a caracterização molecular e a análise da diversidade genética de begomovírus em pimentão e tomateiro em diferentes municípios do Estado de São Paulo: Piraju, Tejupá, Santa Cruz do Rio Pardo, São Pedro do Turvo, São Miguel Arcanjo, Itapetininga, Lins, Sabino, Timburí, Iacanga, Pirajuí, Avaí, Reginópolis e Salto; a identificação de biótipos de B. tabaci por meio da amplificação do gene mitocondrial (citocromo oxidase I - mtCOI) seguido de seqüenciamento ou RFLP utilizando a enzima Taq I e a avaliação para resistência de acessos de Capsicum spp. a dois isolados de ToSRV. A análise da variabilidade foi realizada por meio de seqüenciamento da região da capa protéica (DNA-A) com oligonucleotídeos universais e, paralelamente, as mesmas amostras foram testadas por amplificação por círculo rolante (RCA) sendo, posteriormente, clivadas com a enzima de restrição HpaII. Um total de 812 amostras foi analisado, sendo 709 de pimentão e 103 de tomate. Por PCR tradicional, foram detectadas positivas para presença de begomovírus 98 amostras provenientes de pimentão e 39 de tomateiro, e por RCA-PCR, foram 332 e 82 respectivamente, evidenciando maior sensibilidade desta técnica. Dessas amostras, foram seqüenciadas 39 de pimentão e 25 de tomateiro, verificando-se ocorrência prevalente da espécie ToSRV no estado de São Paulo. Infecção mista com ToSRV e ToYVSV foi observada tomateiro. Por RCA-RFLP, foram observados quatro padrões de clivagem com a enzima HpaII e todos foram confirmados como sendo da espécie ToSRV indicando variabilidade molecular intraespecífica. Para tomateiro, foram observados 18 padrões de restrição, dois idênticos aos verificados em plantas de pimentão indicando, possivelmente, infecção pelos mesmos isolados de ToSRV, porém... / Considering the high incidence of begomoviruses and the whitefly on the field, the objetives of this work were to analyze the genetic diversity of begomoviruses infecting pepper and tomato plants in different counties of São Paulo State: Piraju, Tejupá, Santa Cruz do Rio Pardo, São Pedro do Turvo, São Miguel Arcanjo, Itapetininga, Lins, Sabino, Timburí, Iacanga, Pirajuí, Avaí, Reginópolis and Salto; the identification of biotypes of B. tabaci through the amplification of the mitochondrial gene (cytochrome oxidase I) 4 followed by sequencing the gene or analysis by RFLP using the enzyme TaqI and the evaluation of Capsicum spp. for the resistance source for two isolates of ToSRV. The coat protein from the DNA A of the begomovirus was amplified and sequenced, and the same samples were amplified by rolling circle amplification (RCA) followed by analysis by RCA-RFLP using the HpaII enzyme. A total of 812 samples were analyzed, 709 from pepper and 103 from tomato. By PCR, 98 samples from pepper and 39 from tomato were positives for the presence of begomoviruses, while by RCA-PCR 332 and 82 respectively. Thirty-nine samples from pepper and 25 from tomato were sequenced indicating the prevalence of the ToSRV species in São Paulo State. Mixed infections with ToSRV and ToYVSV were found in tomato plants. By RCA-RFLP four restriction profiles were found for ToSRV in pepper plants. In tomato 18 profiles were observed: two identical as observed for ToSRV in pepper, indicating possible infection with the same ToSRV isolates, a profile for ToSRV and ToYVSV mixed infections and also different profiles for ToSRV isolates didn’t found in pepper plants. The sequencing of 17 samples of B. tabaci mitochondrial citochrome oxidase I gene and analysis by Taq I digestion of whiteflies collected in growers areas of pepper and tomato indicated only the presence of the B biotype... (Complete abstract click electronic access below)

Orientador: Renate Krause Sakate / Banca: Carlos Frederico Wilcken / Banca: Arlete Marchi Tavares de Melo / Banca: Marcelo Agenor Pavan / Banca: Antonio Carlos Maringoni / Resumo: Considerando o aumento de begomovírus e mosca-branca no campo o presente trabalho teve como objetivos a detecção, a caracterização molecular e a análise da diversidade genética de begomovírus em pimentão e tomateiro em diferentes municípios do Estado de São Paulo: Piraju, Tejupá, Santa Cruz do Rio Pardo, São Pedro do Turvo, São Miguel Arcanjo, Itapetininga, Lins, Sabino, Timburí, Iacanga, Pirajuí, Avaí, Reginópolis e Salto; a identificação de biótipos de B. tabaci por meio da amplificação do gene mitocondrial (citocromo oxidase I - mtCOI) seguido de seqüenciamento ou RFLP utilizando a enzima Taq I e a avaliação para resistência de acessos de Capsicum spp. a dois isolados de ToSRV. A análise da variabilidade foi realizada por meio de seqüenciamento da região da capa protéica (DNA-A) com oligonucleotídeos universais e, paralelamente, as mesmas amostras foram testadas por amplificação por círculo rolante (RCA) sendo, posteriormente, clivadas com a enzima de restrição HpaII. Um total de 812 amostras foi analisado, sendo 709 de pimentão e 103 de tomate. Por PCR tradicional, foram detectadas positivas para presença de begomovírus 98 amostras provenientes de pimentão e 39 de tomateiro, e por RCA-PCR, foram 332 e 82 respectivamente, evidenciando maior sensibilidade desta técnica. Dessas amostras, foram seqüenciadas 39 de pimentão e 25 de tomateiro, verificando-se ocorrência prevalente da espécie ToSRV no estado de São Paulo. Infecção mista com ToSRV e ToYVSV foi observada tomateiro. Por RCA-RFLP, foram observados quatro padrões de clivagem com a enzima HpaII e todos foram confirmados como sendo da espécie ToSRV indicando variabilidade molecular intraespecífica. Para tomateiro, foram observados 18 padrões de restrição, dois idênticos aos verificados em plantas de pimentão indicando, possivelmente, infecção pelos mesmos isolados de ToSRV, porém... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Considering the high incidence of begomoviruses and the whitefly on the field, the objetives of this work were to analyze the genetic diversity of begomoviruses infecting pepper and tomato plants in different counties of São Paulo State: Piraju, Tejupá, Santa Cruz do Rio Pardo, São Pedro do Turvo, São Miguel Arcanjo, Itapetininga, Lins, Sabino, Timburí, Iacanga, Pirajuí, Avaí, Reginópolis and Salto; the identification of biotypes of B. tabaci through the amplification of the mitochondrial gene (cytochrome oxidase I) 4 followed by sequencing the gene or analysis by RFLP using the enzyme TaqI and the evaluation of Capsicum spp. for the resistance source for two isolates of ToSRV. The coat protein from the DNA A of the begomovirus was amplified and sequenced, and the same samples were amplified by rolling circle amplification (RCA) followed by analysis by RCA-RFLP using the HpaII enzyme. A total of 812 samples were analyzed, 709 from pepper and 103 from tomato. By PCR, 98 samples from pepper and 39 from tomato were positives for the presence of begomoviruses, while by RCA-PCR 332 and 82 respectively. Thirty-nine samples from pepper and 25 from tomato were sequenced indicating the prevalence of the ToSRV species in São Paulo State. Mixed infections with ToSRV and ToYVSV were found in tomato plants. By RCA-RFLP four restriction profiles were found for ToSRV in pepper plants. In tomato 18 profiles were observed: two identical as observed for ToSRV in pepper, indicating possible infection with the same ToSRV isolates, a profile for ToSRV and ToYVSV mixed infections and also different profiles for ToSRV isolates didn't found in pepper plants. The sequencing of 17 samples of B. tabaci mitochondrial citochrome oxidase I gene and analysis by Taq I digestion of whiteflies collected in growers areas of pepper and tomato indicated only the presence of the B biotype... (Complete abstract click electronic access below) / Doutor

Stucture simple, faible coût, grand espace de travail et technologie mature, ces avantages font que les manipulateurs sériels sont largement utilisés dans de nombreux domaines industriels. Avec le développement rapide de l'industrie et les diverses applications des manipulateurs sériels, de nouvelles exigences strictes sont souhaitées, telles que la stabilité robuste, la grande précision de positionnement et la cadence élevée.Un des moyens efficaces pour améliorer les performances mentionnées est la conception de manipulateurs sériels à découplage dynamique. Dans ce cadre, l'objectif de cette thèse est de valider une structure simple permettant de réaliser un découplage dynamique complet des manipulateurs sériels en tenant compte de la charge embarquée.Le chapitre 1 présente les solutions connues et décrit les inconvénients liés aux différentes techniques permettant une simplification de la dynamique des manipulateurs. L'étude de la bibliographie a permis d'affiner les objectifs à atteindre. Le chapitre 2 traite de la conception de manipulateurs sériels réglables à dynamique linéarisée et découplée. Sans la charge embarquée, la méthode développée réalise le découplage dynamique par rotation inverse des bras et par redistribution optimale des masses. La charge embarquée qui conduit à une perturbation au niveau des équations dynamiques dedécouplage est compensée par la commande.Le chapitre 3 envisage un nouveau concept de découplage dynamique qui consiste à relier aux bras initiaux d'un manipulateur sériel, deux bras additionnels pour réaliser un mécanisme Scott-Russell. Les mouvements opposés des bras du mécanisme Scott-Russell associés à une redistribution optimale des masses permettent de supprimer les termes non linéaires des équations dynamiques du manipulateur. Le modèle linéaire et découplé ainsi obtenu permet de tenir compte de la charge embarquée.Dans le chapitre 4, on considère les propriétés de robustesse (incertitudes paramétriques) de quatre modèles de manipulateurs sériels (un manipulateur couplé, un manipulateur découplé par la commande et les deux manipulateurs découplés qui sont issus des chapitres 2 et 3). Les études qualitatives sont effectuées par simulation en utilisant la même loi de commande optimale et la même trajectoire de référence. Les résultats des simulations permettentde conclure sur la robustesse des manipulateurs décrits aux chapitres 2 et 3 par rapport au manipulateur couplé et au manipulateur découplé par la commande.La méthodologie de conception et les techniques de commande proposées sont illustrées par des simulations réalisées à l'aide des logiciels ADAMS et MATLAB. Les simulations ont confirmé l'efficacité des approches développées. / Simple structure, low cost, large workspace and mature technology, these advantages make the serial manipulators are widely used in many industrialfields. With the rapid development of industry and various applications of serial manipulators, new strict requirements are proposed, such as highstability, high positioning accuracy and high speed operation.One of the efficient ways to improve the mentioned performances is the design of manipulators with dynamic decoupling. Therefore, the goal in thisthesis is to find simple structure pennitting to carry out complete dynamic decoupling of serial manipulators taking into account the changing payload.The review, given in Chapter I, sunmarizes the known solutions and discloses the drawbacks of different techniques permitting a simplification of thedynamics of manipulators. lt allows an identification of objectives that are of interest and should be studied \within the framework of this thesis.Chapter 2 deals with the design of adjustable serial manipulators with linearized and decoupled dynamics. Without payload, the developed methodaccomplishes the dynamic decoupling via opposite rotation of links and optimal redistribution of masses. The payload which leads to the perturbation ofThe dynamic decoupling equations is compensated by the optimal control technique.Chapter 3 deals with a new dynamic decoupling concept, which involves connecting to a serial manipulator a two-link group forming a Scott-Russell mechanism combined with optimal redistribution of masses allows the cancellation of the coefficients of nonlinear terms in the manipulator's dynamic equations. Then, by using the control, the dynamicdecoupling taking into account the changing payload is achieved.In chapter 4, robustness properties (parametric uncertainties) of four various models of serial manipulators (one coupled manipulator, one decoupled manipulator by feedback linearization and the two decoupled manipulators that modeled in chapters 2 and 3) are considered. The given comparison performed via simutations is achieved with the same optimal control law and the same reference trajectory. Simulation results allow one to derive robustness assessments of manipulators described in chapters 2 and 3.The suggested design methodology and control techniques are illustrated by simulations carried out using ADAMS and MATLAB software, which have confirmed the efficiency of the developed approaches.