• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 50
  • 13
  • 8
  • 4
  • 3
  • 2
  • 1
  • 1
  • Tagged with
  • 98
  • 98
  • 14
  • 14
  • 14
  • 13
  • 11
  • 10
  • 10
  • 9
  • 9
  • 9
  • 8
  • 8
  • 8
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Stability of Compounded Pyrimethamine Oral Suspension Stored at Room and Refrigerated Temperature

Brown, Stacy, Huffman, Jessica, Ogle, Amanda, Lewis, Paul 23 July 2016 (has links)
Abstract available in the American Journal of Pharmaceutical Education.
22

Factors Affecting Public Support for Energy-Saving and Carbon-Reduction Policies

Lin, Tzu-ting 09 August 2011 (has links)
To lessen the threats of global climate change, governments have to set and enforce robust polices to save energy and reduce greenhouse gases. But will the public support these policies? And what cognitive factors will affect the public's support? To answer these two questions, this study surveyed a convenience sample consisted of 171 Taichung citizens and 132 Kaohsiung citizens. The survey questionnaire asked questions for 2 variables about the threats of climate change and 5 variables about carbon reducing policies. The variables were vulnerability, severity, personal benefit, social benefit, response efficacy, self-efficacy, and response cost. All these were cognitive variables based on Rogers' (1983) protection motivation theory. The latter 5 variables were assessed for each of the 3 policies mentioned in the questionnaire. The policies were (a) rebate on electric bills for energy saving; (b) energy tax; and (c) ordering public places to keep temperatures above 26 degrees Celsius in summer. Results showed that though respondents moderately supported energy taxation policy, this policy was the least welcomed. Further, personal benefit, social benefit and self-efficacy had significant effects on all three policies. In contrast, perceived vulnerability to climate threats and response cost (policy-induced personal cost) had no effect on any of the policies. Implications of these findings are discussed.
23

Magnetic Studies on the Radicals of Methyl Viologen

Chan, Cheng-Lien 14 July 2008 (has links)
Abstract Methyl Viologen is a kind of organic molecular magnet of current interest which comprises with organic radicals (unpaired electrons). The molecular formula of the sample is (C12H14N2)2+X2-, where ¡§X2-¡¨ denotes a non-magnetic anion (CdI42-, I3-I- etc.). We perform the magnetization (using SQUID magnetometer) and electron paramagnetic resonance (EPR) measurements. Two absorption peaks are observed in EPR spectrum indicating that there are two radical forms in our samples. One of the radicals exists in every sample having the g1-factor value 2.004. The other radical which has the g2-factor 2.001 exists only in certain samples. Interestingly, we find that these samples exhibit ferromagnetism at room temperature. We use Lorentzian profile to quantitatively analyze the EPR spectrum of the samples and derive the ratio (A2/A1) of two different absorption peaks, which represents the amount of g2 radical. The remanent magnetization and saturation magnetization are found to increase as the ratio value increases, indicating that the strength of ferromagnetism is strongly correlated with g2 radical.
24

Palladium Doped Nano Porous Silicon to Enhance Hydrogen Sensing

Luongo, Kevin 24 March 2006 (has links)
A mass manufacturable impedance based, palladium doped porous silicon sensor, was fabricated for hydrogen detection. The sensor was built using electrochemical etching to produce mesoporous silicon. Four nanometers of palladium was defused directly into the porous silicon and another four nanometers of Pd was deposited on the defused surface to enhance sensing. The sensor was tested in a sealed chamber in which the impedance was measured while hydrogen in nitrogen was ranged from 0-2 percent. Unlike conventional hydrogen sensors this sensor responded at room temperature to changes in hydrogen concentration. The electrical impedance response due to adsorption and desorption of hydrogen reacted relatively quickly due to the nanoparticle nature of palladium diffusion in and Pd evaporation on porous silicon.
25

Avaliação da dureza e do grau de conversão de uma resina composta em função do pré-tratamento térmico e da fonte de luz fotopolimerizadora

Saade, Esther Gomes [UNESP] 18 February 2009 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:24:08Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-02-18Bitstream added on 2014-06-13T20:12:01Z : No. of bitstreams: 1 saade_eg_me_arafo.pdf: 674732 bytes, checksum: 3bfed6ac99e5345683bc3cdd8c9e6925 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O objetivo desse trabalho foi investigar a influência do pré-aquecimento da resina composta anterior à fotopolimerização, sobre suas propriedades físicas e mecânicas como: o grau de conversão e dureza. As amostras foram fotopolimerizadas com uma unidade de luz halógena de quartzo-tungstênio (QTH) e uma unidade diodos emissores de luz azul (LED) por 40 s. Os compules de resina composta híbrida foram pré-aquecidos no dispositivo denominado Calset. A conversão dos monômeros a polímeros foi determinada através do FTIR-ATR. A propriedade de dureza foi avaliada no Microdurômetro MMT-3 Microhardness Tester equipado com o diamante Vickers. Para o teste de dureza Vickers cinco amostras para cada grupo (4 mm de diâmetro e 2 mm de espessura) foram confeccionadas com a resina composta pré-aquecida nas seguintes temperaturas: 37ºC, 54ºC e 60ºC (n=5). As amostras foram submetidas ao teste de dureza Vickers imediatamente após a sua confecção. Foram efetuadas 4 medidas no topo e 4 na base de cada amostra. De acordo com a interação entre as duas unidades de luz e o aumento de temperatura da resina composta, os resultados indicam que somente a unidade de luz influenciou nas médias dos valores de dureza Vickers. A unidade LED apresentou valores de dureza mais homogêneos entre o topo e a base da resina composta, evidenciando uma polimerização mais uniforme. O preaquecimento da resina composta não apresentou diferenças estatisticamente significativas nos valores de dureza. Para a avaliação do grau de conversão foram confeccionadas 5 amostras (4 mm de diâmetro e 2 mm de espessura) para cada grupo, utilizando a unidade QTH e LED, e a resina composta nas seguintes temperaturas: 25ºC (temperatura ambiente), 37ºC, 54ºC e 60ºC (n=40). Após a confecção as amostras foram preparadas para a análise do grau de conversão através do FTIR-ATR. Segundo os resultados conclui-se que não houve diferenças estatisticamente significativas. / The aim of this study was to evaluate the physics and mechanical properties of the pre-heating of the composite resin photo-activated. The samples were photo-activated with a light-curing unit QTH and LED for 40 s. The compules of hybrid composite resin for anterior restorations were pre-heated in the device called “Calset”. The monomer conversion was analyzed using the FTIR-ATR. The hardness property was evaluated with microdurometer MMT-3 equipped with diamond Vickers. Five samples were made for each group (4 mm in diameter and 2 mm in thickness) which the composite resin were pre-heated at temperatures three: 37°, 54° and 60°C. Immediately were submitted to hardness test, which the top and bottom surfaces of the samples took, place an impression for quadrant. According to the interaction between both light-curing units and the increase of the temperature of composite resin, the results showed that only lightcuring unit influenced the hardness average values. The LED light showed a cure homogeneous across the surface of the composite resin and good values of Vickers hardness. The pre-heating of composite resins prior to cure did not show statistically significant differences in the hardness values. For to evaluate the degree of conversion, five samples were made (4 mm in diameter and 2 mm in thickness) for each group using light-curing unit QTH and LED, with the composite resin pre-heated at temperatures of 25ºC (room temperature), 37ºC, 54ºC and 60ºC and analyzed in the spectrophotometer. No significant differences were found in the degree of conversion of the composite resin cured with QTH or LED and to different pre-heating of the composite resin. In this study, any evidence was found that type of light-curing unit used and pre-heating of composite resin could improve the degree of conversion.
26

Avaliação da dureza e do grau de conversão de uma resina composta em função do pré-tratamento térmico e da fonte de luz fotopolimerizadora /

Saade, Esther Gomes. January 2009 (has links)
Resumo: O objetivo desse trabalho foi investigar a influência do pré-aquecimento da resina composta anterior à fotopolimerização, sobre suas propriedades físicas e mecânicas como: o grau de conversão e dureza. As amostras foram fotopolimerizadas com uma unidade de luz halógena de quartzo-tungstênio (QTH) e uma unidade diodos emissores de luz azul (LED) por 40 s. Os compules de resina composta híbrida foram pré-aquecidos no dispositivo denominado Calset. A conversão dos monômeros a polímeros foi determinada através do FTIR-ATR. A propriedade de dureza foi avaliada no Microdurômetro MMT-3 Microhardness Tester equipado com o diamante Vickers. Para o teste de dureza Vickers cinco amostras para cada grupo (4 mm de diâmetro e 2 mm de espessura) foram confeccionadas com a resina composta pré-aquecida nas seguintes temperaturas: 37ºC, 54ºC e 60ºC (n=5). As amostras foram submetidas ao teste de dureza Vickers imediatamente após a sua confecção. Foram efetuadas 4 medidas no topo e 4 na base de cada amostra. De acordo com a interação entre as duas unidades de luz e o aumento de temperatura da resina composta, os resultados indicam que somente a unidade de luz influenciou nas médias dos valores de dureza Vickers. A unidade LED apresentou valores de dureza mais homogêneos entre o topo e a base da resina composta, evidenciando uma polimerização mais uniforme. O preaquecimento da resina composta não apresentou diferenças estatisticamente significativas nos valores de dureza. Para a avaliação do grau de conversão foram confeccionadas 5 amostras (4 mm de diâmetro e 2 mm de espessura) para cada grupo, utilizando a unidade QTH e LED, e a resina composta nas seguintes temperaturas: 25ºC (temperatura ambiente), 37ºC, 54ºC e 60ºC (n=40). Após a confecção as amostras foram preparadas para a análise do grau de conversão através do FTIR-ATR. Segundo os resultados conclui-se que não houve diferenças estatisticamente significativas. / Abstract: The aim of this study was to evaluate the physics and mechanical properties of the pre-heating of the composite resin photo-activated. The samples were photo-activated with a light-curing unit QTH and LED for 40 s. The compules of hybrid composite resin for anterior restorations were pre-heated in the device called "Calset". The monomer conversion was analyzed using the FTIR-ATR. The hardness property was evaluated with microdurometer MMT-3 equipped with diamond Vickers. Five samples were made for each group (4 mm in diameter and 2 mm in thickness) which the composite resin were pre-heated at temperatures three: 37°, 54° and 60°C. Immediately were submitted to hardness test, which the top and bottom surfaces of the samples took, place an impression for quadrant. According to the interaction between both light-curing units and the increase of the temperature of composite resin, the results showed that only lightcuring unit influenced the hardness average values. The LED light showed a cure homogeneous across the surface of the composite resin and good values of Vickers hardness. The pre-heating of composite resins prior to cure did not show statistically significant differences in the hardness values. For to evaluate the degree of conversion, five samples were made (4 mm in diameter and 2 mm in thickness) for each group using light-curing unit QTH and LED, with the composite resin pre-heated at temperatures of 25ºC (room temperature), 37ºC, 54ºC and 60ºC and analyzed in the spectrophotometer. No significant differences were found in the degree of conversion of the composite resin cured with QTH or LED and to different pre-heating of the composite resin. In this study, any evidence was found that type of light-curing unit used and pre-heating of composite resin could improve the degree of conversion. / Orientador: Sizenando de Toledo Porto Neto / Coorientador: Alessandra Nara de Souza Rastelli / Banca: Darlon Martins Lima / Banca: José Roberto Cury Saad / Mestre
27

Tailoring the interfacial properties of magnetic multilayers for the observation of skyrmions at room temperature / Etude et contrôle des propriétés interfaciales de multicouches magnétiques pour l'observation de skyrmions à température ambiante

Moreau-Luchaire, Constance 21 December 2016 (has links)
Dans cette thèse, nous montrons que nous avons réussi à observer des skyrmions isolés sub-100nm dans des échantillons Ir|Co|Pt. Ces observations ont été faites via deux techniques différentes : le STXM (technique synchrotron qui permet d’imager l’aimantation hors du plan de l’échantillon) et le MFM (technique de laboratoire qui permet d’imager le gradient de l’aimantation). Nous avons également montré que nous les avions observés à la fois dans les films étendus ainsi que dans des nanostructures (nanodisques de diamètre entre 200 nm et 1 μm, ainsi que les bandes dont la largeur varie de 400 nm à 1 μm). Nous avons également développé deux approches différentes pour estimer l’amplitude DMI dans les échantillons. La première est basée sur la périodicité des domaines dans les échantillons après désaimantation. La deuxième technique est basée sur l’évolution de la taille des skyrmions avec un champ magnétique appliqué hors-plan. Pour la nécessité des simulations micromagnétiques, nous avons également essayé de déterminer l’échange de nos échantillons. Avec cette valeur, le DMI trouvé dans nos échantillons est d’environ 2 mJ/m². Nous avons effectué une étude systématique sur des échantillons avec variation de différents paramètres: nombre de répétitions de la tricouche principale, épaisseur du Co, épaisseur du Pt, épaisseur de l’Ir, composition des couches d’Ir avec W ou AlOx. Nous avons montré que pour tous les systèmes, nous avons pu observer des skyrmions stabilisés à température ambiante grâce au MFM. Nous avons également observé que la densité des skyrmions diminue avec l’augmentation de l’anisotropie effective. / We have been able to successfully observe isolated sub-100nm skyrmions in Ir|Co|Pt samples. Moreover, we have been able to observe them with two different techniques: STXM - a synchrotron technique that maps the out-of-plane magnetization of a sample, and MFM - a laboratory technique that images the gradient of the magnetization. We have also shown that we have stabilized them in extended films as well as in nanostructures (nanodisks with diameter from 200 nm to 1 μm, as well as stripes with width from 400 nm to 1 μm). Secondly, we have developed two different approaches to estimate the DMI amplitude in samples. The first one is based on the mean domain periodicity in samples after demagnetization. The second technique is based on the size evolution of skyrmions with applied out-of-plane magnetic field. For the need of the micromagnetic simulations, we have also tried to determine the exchange stiffness of our samples. With this value, the DMI aplitude found in our samples is about 2 mJ/m². We have performed a systematic study on samples with variation of different parameters : number of repetitions of the main trilayers, Co thickness, Pt thickness, Ir thickness, composition of the buffer layers, and switching Ir with W or AlOx. We also observed that the density of skyrmions is decreasing with increasing effective anisotropy.
28

Drawing Functional Micropatterns on Flexible Polymer Substrates via VUV-lithography / VUVリソグラフィによる可撓性高分子基板上への機能性微細パターンの構築

Wu, Cheng-Tse 23 September 2020 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第22776号 / 工博第4775号 / 新制||工||1747(附属図書館) / 京都大学大学院工学研究科材料工学専攻 / (主査)教授 杉村 博之, 教授 邑瀬 邦明, 教授 宇田 哲也 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM
29

Optimalizace vnitřního prostředí historické místnosti / Optimization of indoor climate in a historical room

Vaňková, Klára January 2016 (has links)
Diploma thesis solves an indoor climate specializing to historical buildings. The thesis is devided to three parts. First part contains The experiment in historical rooms took place at Austerlitz chaetau. Humidity and temperature was mesuared and the impact of these two parametres was evaluated according to chosen methodic. Diploma thesis sol-ves optimalization of internal microclimate of these two rooms. Two types of heating are designed in accordance with technical standards. These types are evaluated according to different criterions and the best type of heating is chosen – infraheating.
30

Tomografische Rekonstruktion der Raumtemperaturverteilung aus einer Raumimpulsantwort

Bleisteiner, Marcus, Barth, Markus, Raabe, Armin, Holstein, P. 03 November 2017 (has links)
Temperature can be estimated by acoustic propagation time measurements along known sound paths. By using a multitude of known sound paths in combination with a tomographic reconstruction technique a spatial and temporal resolution of the temperature field can be achieved. Based on it, this article focuses on an experimental method in order to determine the spatially differentiated development of room temperature with only one loudspeaker and one microphone. The theory of geometrical room acoustics is being used to identify sound paths under consideration of reflections. The propagation time along a specific sound path is derived from the room impulse response. Temporal variances in room impulse response can be attributed primarily to a change in air temperature and airflow. It is shown that in the absence of airflow a three-dimensional acoustic monitoring of the room temperature can be realized with a fairly limited use of hardware. / Die Temperatur kann mithilfe von akustischen Laufzeitmessungen auf definierten Schallstrecken ermittelt werden. Der Einsatz multipler Schallstrecken, in Verbindung mit einem tomografischen Rekonstruktionsverfahren, erlaubt eine räumliche Auflösung der genannten klimatologischen Größe. Aufbauend darauf, befasst sich dieser Artikel mit einer experimentellen Methode zur Erfassung der räumlich und zeitlich aufgelösten Entwicklung der Raumtemperatur mit lediglich einem Lautsprecher und einem Mikrofon. Die Theorie der geometrischen Raumakustik wird genutzt, um Schallstrecken, unter der Berücksichtigung von Reflexionen, zu identifizieren. Die zu den Ausbreitungswegen gehörenden Laufzeiten werden aus einer gemessenen Raumimpulsantwort abgeleitet. Zeitliche Varianzen in Raumimpulsantworten sind in erster Linie auf die Veränderung der Lufttemperatur und von Strömungsverhältnissen zurückzuführen. Es wird gezeigt, dass bei Abwesenheit von Raumluftströmungen, eine dreidimensionale, akustische Überwachung der Raumtemperatur mit einem sehr geringen Einsatz an Messtechnik realisiert werden kann.

Page generated in 0.03 seconds