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1

Goulart, Jair Trapé 1987. "Vulnerabilidade de miócitos cardíacos a campos elétricos de alta intensidade = influência da estimulação beta-adrenérgica = The lethal effect of high-intensity electric fields on cardiac myocytes: influence of the beta-adrenergic pathway". [s.n.], 2012. http://repositorio.unicamp.br/jspui/handle/REPOSIP/259400.

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Orientadores: José Wilson Magalhães Bassani, Rosana Almada Bassani
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação
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Resumo: A aplicação de campos elétricos de alta intensidade (CEAI) no coração é realizada frequentemente durante tentativas de reversão da fibrilação, e para gerar sincronismo cardíaco com o uso de marca-passos. Entretanto, este procedimento rotineiro pode causar danos ao miocárdio. O objetivo deste trabalho foi investigar se a estimulação ?-adrenérgica afeta a vulnerabilidade de miócitos ventriculares ao CEAI, uma vez que, durante a fibrilação ventricular, há aumento reflexo do tônus simpático, em virtude da consequente hipotensão arterial, e a administração de catecolaminas é um procedimento comum neste tipo de emergência. Miócitos foram isolados do ventrículo esquerdo de ratos Wistar adultos por digestão enzimática. As células foram perfundidas com solução de Tyrode a 23 °C e estimuladas a 0,5 Hz. Aplicou-se CEAI em intensidades crescentes até que fosse induzida uma lesão letal na célula. A probabilidade de morte celular foi determinada em função da amplitude do CEIA e da máxima variação estimada do potencial de membrana (?Vmax) por análise de sobrevivência (curva de letalidade). Destas curvas, obteve-se o parâmetro EL50 (valor de CEAI ou ?Vmax com probabilidade de letalidade de 0,5). A estimulação ?-adrenérgica, pela perfusão com 10 nM de isoproterenol (ISO), foi realizada na ausência e presença de 150 nM de metoprolol (MET, bloqueador de adrenoceptores ?1), 10 ?M de H-89 (inibidor de PKA) e 500 nM de BIS I (inibidor de PKC), bem como após protocolo para minimizar o aumento de mobilização celular de Ca2+. As curvas foram comparadas por teste de Mantel-Cox. O tratamento com ISO promoveu o deslocamento da curva para a direita (p < 0,01) e EL50 aumentou de 85 para 100 V/cm. MET e H-89 aboliram o efeito protetor do ISO, e, quando perfundidos na ausência de ISO, não tiveram quaisquer efeitos sobre a indução de letalidade por CEAI. A redução da mobilização de Ca2+ e o tratamento com BIS I não alteraram as curvas de letalidade, na presença ou ausência de ISO, mas provocaram significante aumento no tempo de recuperação das células após um choque não letal. As curvas em função de ?Vmax foram similares àquelas em função da intensidade do campo. Os resultados mostram que a estimulação ?-adrenérgica é capaz de proteger os miócitos dos efeitos deletérios do CEAI, permitindo que a célula suporte maiores ?Vmax. A proteção parece ser mediada por adrenoceptores ?1 e PKA, e possivelmente envolve ativação de mecanismos de reparo. Estas vias de proteção podem ser futuramente exploradas para atenuar os danos miocárdicos causados pela desfibrilação/cardioversão
Abstract: The myocardium is exposed to high-intensity electric fields (HIEF) during cardiac electric defibrillation, which may reverse life-threatening arrhythmias, but also cause cell damage. Impairment of cardiac pumping during ventricular fibrillation is usually associated with high sympathetic tone, and catecholamine infusion is a common procedure for the emergencial treatment of this arrhyhmia. The present study was carried out to investigate whether adrenergic stimulation affects the vulnerability of ventricular myocytes to the lethal effect of HIEF. Left ventricular myocytes were isolated from adult Wistar rat hearts by collagenase digestion. Under perfusion with Tyrode's solution at 23 ºC, cyclic contractile activity was evoked by stimulation at 0.5 Hz. A HIEF pulse was then applied, after which cells were allowed to rest and recover from the shock. Afterward, the protocol was repeated increasing HIEF amplitude until cell death ensued. The probability of cell death as a function of the field intensity or the estimated maximum change in membrane potential, ?Vmax (lethality curve) was determined by survival analysis. The protocol was carried out during exposure to 10 nM isoproternol (ISO), in the absence and presence of the ?1-adrenoceptor blocker metoprolol (MET, 150 nM), the PKA inhibitor H-89 (10 ?M), the PKC inhibitor BIS I (500 nM), or after a protocol designed to attenuate the increase in cell Ca2+ mobilization by ISO. Lethality curves were compared with the Mantel-Cox test. Exposure to ISO produced a marked rightward shift of the lethality curves (p< 0.01), and the field intensity associated with the cell death probability of 0.5 (EL50) was increased from 85 to 100 V/cm. Treatment with MET or H-89 alone did not significantly affect the curves, but completely abolished ISO protective effect. Decreasing Ca2+ mobilization and BIS I treatment did not produce significant effects on the lethality curves, either in the absence or presence of ISO, but they increased the time spent to cell recovery after a non-lethal shock. Similar results were obtained for the lethality curve as a function of ?Vmax. Therefore, ?-adrenergic stimulation confers protection to ventricular myocytes from the lethal effects of HIEF, even though cells apparently experience higher variations of ?Vmax, which should lead to extensive electroporation. This effect, which seems to be mediated by ?1-adrenoceptors and dependent on PKA activation, possibly involving recruitment of membrane repair mechanisms. This protective effect may be further explored as a means to attenuate HIEF deleterious effects on cardiac function that frequently result from electric defibrillation/cardioversion
Mestrado
Engenharia Biomedica
Mestre em Engenharia Elétrica
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2

Hermany, Jiří. "Záření soustav antén v blízké zóně". Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2008. http://www.nusl.cz/ntk/nusl-217536.

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The aim of my diploma thesis is to analyze the antenna array radiation and to produce the antenna array radiation computation program. The program should display the electric and magnetic intensity and radiation power density distribution over the planar or cylindrical surface in the near-field area. The antenna array analyzed in this paper consists of a number of elementary dipoles placed in a row with a reflector which represents the conductive board situated in parallel to the row of dipoles. The demonstration program was built in MATLAB and allows computing and displaying the computed values components of antenna array radiation on the planar or the cylindrical surface. The program also allows saving computed values, saving displayed graphs, or saving the adjusted parameters of antenna array. The created program can be used for the presentation of the antenna array radiation in a school laboratory or for the graphical representation when a new antenna is designed.
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3

Ткаленко, Р. Г. "Чисельне моделювання аксіально-симетричних електронних потоків у НВЧ приладах типу ЛБХ". Master's thesis, Сумський державний університет, 2019. http://essuir.sumdu.edu.ua/handle/123456789/73319.

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4

Harvey, Christopher. "Electron dynamics in high-intensity laser fields". Thesis, University of Plymouth, 2010. http://hdl.handle.net/10026.1/301.

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We consider electron dynamics in strong electromagnetic fields, such as those expected from the next generation of high-intensity laser facilities. Beginning with a review of constant classical fields, we demonstrate that the electron motion (as given by the Lorentz force equation) can be divided into one of four Lorentz invariant cases. Parameterising the field tensor in terms of a null tetrad, we calculate the radiative energy spectrum for an electron in crossed fields. Progressing to an infinite plane wave, we demonstrate how the electron orbit in the average rest frame changes from figure-of-eight to circular as the polarisation changes from linear to circular. To move beyond a plane wave one must resort to numerics. We therefore present a novel numerical formulation for solving the Lorentz equation. Our scheme is manifestly covariant and valid for arbitrary electromagnetic field configurations. Finally, we reconsider the case of an infinite plane wave from a strong field QED perspective. At high intensities we predict a substantial redshift of the usual kinematic Compton edge of the photon emission spectrum, caused by the large, intensity dependent effective mass of the electrons inside the laser beam. In addition, we find that the notion of a centre-of-mass frame for a given harmonic becomes intensity dependent.
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5

Jennings, Jessica Amber. "Regulation of gene expression in response to continuous low Intensity direct current electrical fields". Birmingham, Ala. : University of Alabama at Birmingham, 2007. https://www.mhsl.uab.edu/dt/2009r/jennings.pdf.

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Thesis (Ph. D.)--University of Alabama at Birmingham, 2007.
Additional advisors: Susan Bellis, Vladimir Fast, Chi-Tsou Huang, Donald Muccio. Description based on contents viewed June 23, 2009; title from PDF t.p. Includes bibliographical references.
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6

Hangya, Josef. "Účinky elektrického namáhání na vlastnosti elektroizolačních materiálů". Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2014. http://www.nusl.cz/ntk/nusl-220958.

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Diploma thesis treat of effect of direct, alternate and pulse electrical stress on the properties surveyed electrical insulating material. Object of this experiment is crystalline high-density polystyrene QUINN PS. To monitor the stress is used the method of dielectric relaxation spectroscopy. Under examinations are the resultant dielectric spectra, which constitute the frequency dependencies of components of complex permitivity. Samples of the selected material are exposed to effects of alternate and pulse electrical stress on the different intensities of the electric field. In the direct field are then monitored absorption characteristics and specific volume resistance of the samples.
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7

Sánchez, Vega Rogelio. "Effects of high-intensity pulsed electric fields on the bioactive compounds stability and enzymes of broccoli juice". Doctoral thesis, Universitat de Lleida, 2016. http://hdl.handle.net/10803/383050.

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This thesis doctoral was focused on evaluating the influence of HIPEF-processing parameters (electric field strength, treatment time and polarity) on bioactive compounds (chlorophylls, carotenoids, vitamin C and total phenolic compounds), minerals, amino acids and enzymes (myrosinase, polyphenol oxidase and lipoxygenase) of broccoli juice. Results of HIPEF-processed broccoli juice were compared with those of thermally treated (90 °C/60 s) and untreated juices. The HIPEF processing parameters significantly influenced the relative content (RC) of lutein, β-carotene, total phenolics (TP), vitamin C, minerals and amino acids, relative antioxidant capacity, as well as the RC of chlorophylls degradation compounds, the enzymes chlorophyllase, polyphenol oxidase, lipoxygenase and color difference (ΔE). However, polarity did not exert influence neither on Chl a, Chl b nor on ΔE. HIPEF-treated broccoli juice exhibited superior content of chlorophylls, carotenoids, TP, vitamin C, minerals, amino acids, and antioxidant capacity than those thermally treated or untreated juice. Also, the highest ΔE (7.89) was observed in the broccoli juice processed by heat.
La presente tesis doctoral se centro en evaluar la influencia de los paramétros de procesamiento de HIPEF (intensidad de campo eléctrico, tiempo de tratamiento y polaridad) sobre los compuestos bioactivos (clorofilas, carotenoides, vitamina C y compuestos fenólicos totales), minerales, aminoácidos y enzimas (mirosinasa, polifenol oxidasa y lipoxigenasa) de zumo de brócoli. Los resultados del zumo de brócoli procesado con HIPEF fueron comparados con aquellos del zumo tratado térmicamente (90 °C/60 s) y del zumo sin procesar. Las parámetros de procesamiento con HIPEF influyó significativamente sobre el contenido relativo (RC) de luteína, β-caroteno, fenoles totales (TP), vitamina C, minerales y aminoácidos, capacidad antioxidante relativa, así como el RC de compuestos de degradación de clorofila, las enzimas clorofilasa, polifenol oxidasa, lipoxigenasa y diferencia de color (ΔE). Sin embargo, la polaridad no tuvo influencia sobre Chl a, Chl b ni sobre ΔE. El zumo de brócoli tratado con HIPEF mostró un mayor contenido de clorofilas, carotenoides, TP, vitamina C, minerales, aminoácids, y capacidad antioxidante que aquellos procesados térmicamente y sin tratar. Además, la ΔE más elevada (7.89) fue observada en el zumo de brócoli procesado con calor.
La present tesi doctoral es va centrar en avaluar la influència dels paràmetres de processament de HIPEF (intensitat de camp elèctric, temps de tractament i polaritat) sobre els compostos bioactius (clorofil•les, carotenoides, vitamina C i compostos fenòlics totals), minerals, aminoàcids i enzims (mirosinasa, polifenol oxidasa i lipoxigenasa) de suc de bròquil. Els resultats del suc de bròquil processat amb HIPEF van ser comparats amb aquells del suc tractat tèrmicament (90 °C/60 s) i del suc sense processar. Les paràmetres de processament amb HIPEF va influir significativament sobre el contingut relatiu (RC) de luteïna, β-carotè, fenols totals (TP), vitamina C, minerals i aminoàcids, capacitat antioxidant relativa, així com el RC de compostos de degradació de clorofil•la, els enzims clorofilasa, polifenol oxidasa, lipoxigenasa i diferència de color (ΔE). No obstant això, la polaritat no va tenir influència sobre Chl a, Chl b ni sobre ΔE. El suc de bròquil tractat amb HIPEF va mostrar un major contingut de clorofil•les, carotenoides, TP, vitamina C, minerals, aminoácids, i capacitat antioxidant que aquells processats tèrmicament i sense tractar. A més, la ΔE més elevada (7.89) va ser observada en el suc de bròquil processat amb calor.
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8

Cameron, Douglas Gordon. "Studies on the use of high intensity pulsed electric fields for the inactivation of problematic food-borne microorganisms". Thesis, University of Strathclyde, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.401574.

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9

Morozionkov, Jevgenij. "Pramoninio dažnio elektromagnetinių laukų tyrimas". Master's thesis, Lithuanian Academic Libraries Network (LABT), 2006. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2006~D_20060613_110343-33965.

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Literary review, according to theoretical and experimental researches, it was noticed that electromagnetic fields of industrial frequency influence the human and environment. Power force of low frequentative electromagnetic beaming is little. However electromagnetic beams of these low frequentative domains have clearly expressed electrical and magnetic fields which affect the separate parts of human body. The most sensitive parts to the effect of electromagnetic fields are the nervous system and the neuroendocrine system. The biggest sources of electromagnetic fields are the domestic appliances, the installations of electricity transmission, transference and the distributing installations in residential and working places. Electromagnetic fields are generated with electric installations and spread in space by 1/r3; 1/r2 and 1/r law. It is typical of the value change of electric and magnetic fields. Parameter value of electromagnetic fields is solved with electricity installations tension, stream and the location of analyzed point in point of installations. Summing up the wide energetic net of our country, the fact of usable electric installations (which create electromagnetic fields in residential and working places) assume the marked social signification, there is posed the opportunity to forecast the available values of low electromagnetic fields effect, and to forecast means to remove it.
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10

Almousa, Almaksour Khaled. "Etude de l’émission cathodique sous vide en présence d'un champ électrique intense et des paramètres physiques gouvernant son intensité". Thesis, Paris 11, 2014. http://www.theses.fr/2014PA112017/document.

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L’émission électronique par effet de champ est un domaine qui concerne de nombreuses applications techniques. Dans ce travail, nous avons réalisé une étude essentiellement expérimentale des différents paramètres susceptibles d’avoir une influence sur l’émission électronique. En première partie, nous exposons les résultats obtenus pour un champ électrique homogène correspondant aux faibles intensités de courant. Le rôle de la distance inter-électrodes à champ constant et l’influence de la rugosité de surface sur l’émission électronique ont été étudiés. Nous discutons la méthode classique de Fowler-Nordheim utilisée pour le dépouillement des mesures en y portant un regard critique. Un modèle simple visant à prendre en compte l’échauffement des sites émetteurs est proposé. La seconde partie concerne l’effet de l’injection de gaz sur l’émission électronique, effet qui se traduit par une diminution du courant émis quand on augmente la pression de 10⁻⁶ Pa à 10⁻² Pa à champ macroscopique constant. Nous exposons des résultats montrant un effet de seuil concernant l’apparition de l’effet du gaz sur l’émission électronique. Nous présentons également des résultats pour différents matériaux de cathode et pour différents gaz (He, H₂, N₂, Ar). Une réversibilité de cet effet est montrée après le pompage pour redescendre à 10⁻⁵ Pa. La décroissance de courant par effet de gaz est interprétée par la diminution de la valeur du facteur d’accroissement local du champ électrique (β) au niveau des émetteurs à cause du bombardement de ces sites par les ions créés à leur proximité. Un calcul du flux d’ions bombardant un site émissif a permis d’estimer le temps nécessaire pour modifier un émetteur de façon cohérente avec les observations expérimentales. La théorie de la migration des atomes en surface de l’électrode en présence d’un champ électrique est proposée pour expliquer la réversibilité de l’effet de gaz observée qui est, selon cette théorie, liée à l’augmentation de la valeur de β au niveau des émetteurs
Field electronic emission is a domain which concerns numerous different technical applications. In this work, we have taken an essentially experimental approach to study various parameters having influence on field emission. In the first part of the thesis, we have described the results obtained with a homogeneous electric field with relatively weak field emission. The role of the inter-electrode distance at constants field as well as that of the cathode surface roughness on field emission are studied. The classical method of Fowler-Norheim was then used for the analysis of the measurements. A simple model aiming to take into account the effect of the heating of the emission sites is then proposed. The second part of the theses concerns the effect of the injection of gas on the field emission; this effect being to significantly reduce emission intensity when the gas pressure is raised from 10⁻⁶ to 10⁻² Pa at constant field. A threshold value of emission intensity is shown to be necessary for the observation of this gas effect. The effect of different gas types (He, H₂, N₂, Ar) and cathode materials are also described. The gas effect is shown to be reversible upon lowering of the gas pressure to 10⁻⁵ Pa. The reduction in current is interpreted by a lowering of the field enhancement factor (β) of emission sites by ionic bombardment by ions created locally (within distances on the order of microns) near the cathode surface. A calculation of the flux of bombarding ions is used to estimate the time necessary to modify an emission site in a way corresponding to the observations. The phenomenon of surface migration in the presence of intense electric field is then proposed to explain the reversibility of the gas effect, increasing the local field enhancement factor
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11

Kuprusevičius, Vaidas. "Transformatorinių pastočių skleidžiamų elektromagnetinių laukų tyrimas". Master's thesis, Lithuanian Academic Libraries Network (LABT), 2010. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2010~D_20100618_134150-69461.

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Atlikus literatūros apžvalgą, remiantis teoriniais ir eksperimentiniais tyrimais, įsitikinta, kad elektromagnetiniai laukai turi įtakos žmogui ir aplinkai. Elektromagnetinio lauko poveikiui daugiausiai jautri centrinė nervinė ir neuroendokrininė sistemos. Didžiausi elektromagnetinių laukų šaltiniai, gyvenamojoje ir darbo aplinkoje, yra buitiniai prietaisai, elektros perdavimo, transformavimo ir skirstomieji įrenginiai. Elektros įrengimų kuriami elektromagnetiniai laukai, erdvėje sklinda pagal 1/r3; 1/r2 ir 1/r dėsnius. Tai charakteringa tiek elektrinių, tiek magnetinių laukų verčių kitimui. Elektromagnetinių laukų parametrų vertę apsprendžia elektros įrenginių įtampa, srovė ir tiriamo taško padėtis įrenginių atžvilgiu. Įvertinant labai platų mūsų šalies energetikos tinklą, naudojamų elektros įrenginių, kuriančių elektromagnetinius laukus gyvenamoje ir darbo aplinkoje, duomenys apie tai įgauna ženklią socialinę prasmę, sudaroma galimybė prognozuoti galimas silpnų elektromagnetinių laukų poveikio reikšmes, numatyti priemones joms pašalinti.
Literary review, according to theoretical and experimental researches, it was noticed that electromagnetic fields of industrial frequency influence the human and environment. The most sensitive parts to the effect of electromagnetic fields are the nervous system and the neuroendocrine system. The biggest sources of electromagnetic fields are the domestic appliances, the installations of electricity transmission, transference and the distributing installations in residential and working places. Electromagnetic fields are generated with electric installations and spread in space by 1/r3; 1/r2 and 1/r law. It is typical of the value change of electric and magnetic fields. Parameter value of electromagnetic fields is solved with electricity installations tension, stream and the location of analyzed point in point of installations. Summing up the wide energetic net of our country, the fact of usable electric installations (which create electromagnetic fields in residential and working places) assume the marked social signification, there is posed the opportunity to forecast the available values of low electromagnetic fields effect, and to forecast means to remove it.
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Soueid, Malak. "Contribution au développement et à la caractérisation d’applicateurs pour les études bioélectromagnétiques portant sur les ondes radiofréquences et les impulsions électriques nanosecondes de haute intensité". Thesis, Limoges, 2016. http://www.theses.fr/2016LIMO0081/document.

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Dans cette thèse, nous proposons et étudions des systèmes d’exposition en vue d’explorer les effets biologiques sanitaire et thérapeutique des ondes électromagnétiques sur le vivant. Nous proposons une antenne micro-onde pour l’ablation thermique des tumeurs cancéreuses du foie à 2.45 GHz. Son originalité réside en ses dimensions miniatures et la possibilité de l’insérer dans le foie par voie endoscopique. Pour cette antenne, un débit d’absorption spécifique (DAS) supérieur à 50 W/kg/W inc a montré une zone exposée de 1-cm de diamètre. Nous proposons ensuite une cellule transverse électromagnétique (TEM) avec une ouverture fermée par un matériau transparent conducteur l’Indium tin oxyde (ITO). Cette cellule TEM peut être utilisée pour évaluer les effets sanitaires potentiels des signaux de télécommunications sans fils. Ce système permet l’observation microscopique en temps réel du milieu biologique exposé, à travers son ouverture fermée par l’ITO. L’influence de la présence de l’ouverture et de la couche d’ITO sur le DAS dans le milieu exposé a été évaluée. Les valeurs du DAS obtenues à 1.8 GHz dans le milieu exposé dans la cellule TEM avec l'ouverture fermée ou non par l’ITO étaient de 1.1 W/kg/W inc et 23.6 W/kg/W inc, respectivement. Une excellence homogénéité du DAS a été obtenue dans le milieu en présence de l’ITO. Enfin, nous proposons plusieurs dispositifs spécifiques pour l’exposition des cellules biologiques aux champs électriques pulsés nanosecondes de haute intensité (nsPEFs). Les effets biologiques des nsPEFs sont utilisés pour des applications dans le domaine médical et en biotechnologie. Nous proposons deux dispositifs à électrodes en contact direct avec le milieu biologique et trois dispositifs à électrodes isolées. Nous démontrons l’adaptation de ces dispositifs aux impulsions courtes de durée 3-ns et la capacité de ceux à électrodes en contact à fournir des champs intenses de l’ordre de quelques MV/m. Nous illustrons aussi l’importance des dispositifs isolés pour délivrer des impulsions ultracourtes
In this thesis, we propose and study exposure systems to explore healthy and therapeutic biological effects of EM signals. We propose a microwave antenna for thermal ablation of liver tumors at 2.45 GHz. Its original feature consists in its reduced dimensions that permits the endoscopic insertion in the zone to be treated. For this antenna, a specific absorption rate (SAR) greater than 50 W/kg/W inc showed an exposed zone of 1-cm diameter. We propose a transverse electromagnetic cell (TEM) with an aperture sealed with a transparent conducting material Indium tin oxide (ITO).This TEM cell can be used to study the potential effects of wireless communication systems on biological cells. This delivery device allows real-time observation of biological cells during exposure across the aperture sealed with ITO. The effect of the aperture and the ITO layer presence on the SAR in the exposed sample was evaluated. The SAR values obtained at 1.8 GHz in the sample exposed in the TEM cell with the sealed or non-sealed aperture of 20-mm diameter were 1.1 W/kg/W inc and 23.6 W/kg/W inc, respectively. An excellent homogeneity of SAR was achieved in the medium in the presenceof ITO. Finally, we propose several devices for the exposure of biological medium to nanosecond pulsed electric field with high intensity (nsPEFs). The biological effect of nsPEFs are used in biotechnology and medicine. We propose two devices with electrodes in direct contact with the biological medium and three devices with isolated electrodes. We demonstrate their adaptation for 3-ns duration pulses and the suitability of those with electrodes in contactwith the biological medium to provide high intensities fields in the order of several MV/m. We demonstrate the importance of the isolated devices for delivering ultrashort pulses
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13

Ho, Sheng-Hao y 何晟豪. "Simulating and Analyzing the Intensity of the Electric-field in an RFID Portal". Thesis, 2013. http://ndltd.ncl.edu.tw/handle/xj8bhb.

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碩士
國立臺北科技大學
製造科技研究所
101
When RFID technology was bringing in business company, the first problem that we might face is how to contain the stability of RFID tag’s read-rate. Due to so many interferences, such as environment, tag’s positions, antenna’s gain ability and design…etc, all interferences could cause the read-rate declining. If we can build a way to setup the antenna’s parameter, and remove the interferences of RFID read-rate, we must could increase more benefit of this technology. My research is talked about how to use the simulation software—HFSS(built by Ansoft Co.) to adjust the RFID portal, and to increase the read-rate stability(when high quantity tags in). Then we use experiments and simulations to make a standard way to adjust RFID portal, and help the RFID portal users to utilize simply and standardly.
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14

Koehler, Robert. "Intensity error sensing in the active control of free field sound radiation / Robert Keohler". 2001. http://hdl.handle.net/2440/21780.

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"28th September 2001"
Bibliography: p. 285-310.
xlvi, 350 p. : ill. (some col.), plates (col.) ; 30 cm.
Title page, contents and abstract only. The complete thesis in print form is available from the University Library.
This thesis describes by theory and experiment, the effectiveness of an alternate error sensing strategy suitable for the control of general free field sound radiation problems, namely active intensity. In this research, active intensity error sensing has been rigorously analysed: 1. in the near and far field of the disturbance source; 2. to determine its ability to lead to global control via sound power attenuation; 3. in a real control system. The performance of active intensity error sensors were evaluated both analytically and experimentally in progressively more complex environments to identify their capabilities and limitations.
Thesis (Ph.D.)--University of Adelaide, Dept. of Mechanical Engineering, 2001
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15

Fu, Chien-Hua y 傅建樺. "Analysis of electric field intensity between zero-potential and charged conductors in insulation oil". Thesis, 2011. http://ndltd.ncl.edu.tw/handle/y9jtuz.

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碩士
中原大學
電機工程研究所
99
It is necessary to consider the electric field intensity between zero-potential and charged conductors when designing the interior of a transformer. When the interior intensity of a transformer exceeds the maximum limit, the insulation will be destroyed and the life-span of the transformer will be reduced. This technical report addresses this problem to ensure the security of a transformer usage and reduce the design cost. It is expected to know the interior of a transformer detailedly.
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16

Wang, Wei-Hsin y 王偉欣. "Effect of the Design of Wire Electrode and Process Parameters on the Electric Field Intensity of Polypropylene Electret Nonwoven Fabric". Thesis, 2002. http://ndltd.ncl.edu.tw/handle/8sbub8.

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碩士
逢甲大學
紡織工程所
90
As the improvement of the technology and the living quality, the high performance filters have been a necessity for the industrial and the consumer product. Recently, the quantity of the filter made by the non-woven material is increased day by day. The consuming volume of the non-woven material made by the organic synthesis fiber for the air filtration is increasing steadily also. The main topic for this research is focused on the influence about the charging capability carried by the modified wire electrode and the capability of keeping the electrostatic voltage carried of the electret made by polypropylene melt-blow nonwoven fabric. The process parameters in the experiment are design of the electrode, electric field intensity of the charge( 167 kV/m, 333 kV/m, 500 kV/m, 667 kV/m), heating temperature (30~35 0C, 50~55 0C, 70~75 0C), cooling temperature( 23 0C, 15 0C, 10 0C, 5 0C, 0 0C, -5 0C) and the distance between the electrodes (70 mm, 140 mm, 210 mm). In order to increase the charging ability of the electret, we install a 165 W UV lamp at the position before the area of elimination of electrostatic voltage in the machine for the purpose of the initiation of the material by the exposure of light. Besides, the capability of the charging and keeping of the electricity of the electret can be improved by the installation of heating equipment before the electrode area of the machine and the cooling equipment in the area of the electrodes located. From the result of this experiment, we found the stronger intensity of the surface electrical field of the electret can be got is under the situation when the charged intensity reaches 500 kV/m when we use 100 μm golden wire electrode as the material for the wire electrode and pick up the copper pipe with 10 mm radius for this research. This combination will lower the interference of the electric field intensity between the electrodes. The best condition for the charging efficiently of the electricity into the electret is to assign the heating temperature around 50~55 0C and the cooling temperature as 150C respectively. The charging space of the machine can be reduced by the choice the copper— pipe electrode, because the intensity of the charging field will not be influenced when the distance between the electrodes becoming smaller.
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17

Chou, Jung-Feng y 周榮峯. "Effect of the Design of Needle Electrode and Process Parameters on the Electric Field Intensity of Polypropylene Electret Nonwoven Fabric". Thesis, 2002. http://ndltd.ncl.edu.tw/handle/vk4j9k.

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碩士
逢甲大學
紡織工程所
90
The most convenient and plentiful life which human being never had before is equipped with by the improvement of the science and technology. Unformatually, the pollution problem follows the progress of the science also and our environmental is destroyed gradually. The scientists around the world are doing their best to bring higher quality air back to the earth for us to breath. The main topic in this research is studying the influence of surface electric field intensity from the processing parameters for we to made the electret air filter and the efficiency of the filter after treated with the discharge process. The parameters in this research are voltage for discharge, the height of the electrodes, processing time in the electric field, temperature for pre-heating treatment, heating temperature in the electric field, cooling temperature and the type of the electrodes we use. In order to increase the stability of the surface electric field intensity of the electric filter, the equipment for elimination of the electrostatic is installed at the feeding area of the charging machine. Another way we use at the same time to increase the intensity of the surface electric field is to install a 165 W UV lamp at the position after the part of elimination of electrostatic in the machine. We wish the outer layer of the electron in the materials can be stimulated to get the stronger intensity of the surface electric field bring by the effect of opto-electret. By the result of this research, the better electric field intensity can be inquired by the fine needle type of the electrode and the charge intensity can be reached to 857.14 kV/m. The electret material can capture more charge if the pre-heating temperature can set as 60~65 0C and the intensity of the electric field is stronger also. The decrease about the intensity of the electric field intesity will become slower if the cooling temperature of the electret became 10 0C.
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18

Chen, Bo-Syuan y 陳柏軒. "Broadband Electrical Field Intensity Detector". Thesis, 2012. http://ndltd.ncl.edu.tw/handle/42233612764521705289.

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碩士
國立勤益科技大學
電子工程系
100
This thesis proposed a broad band electrical field intensity detector. The circuit combines with logic integrated circuit and RF circuit. It can detect frequency from 50MHz to 3GHz. The detector can be used in RFID system, cellular phone and microwave oven signal detection. The detector also equipped with LED display and sound buzzer for different kinds of output in showing the strength of electric field. In comparison with the available products nowadays, this detector provides more cheaper, more smaller and effective operation benefit.
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19

Wan, Xi-Haw y 萬子豪. "A Novel Dual-Electrode Plug to Achieve Intensive Electric Field for High Performance Ignition". Thesis, 2015. http://ndltd.ncl.edu.tw/handle/12475199352328026604.

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碩士
國立高雄第一科技大學
綠色能源及IC設計產業碩士專班
103
This thesis proposes a novel dual-electrode plug to achieve high performance ignition. The proposed plug not only can establish a much intensive electric field to promote ignition efficiency, but further saves fuel consumption and decreases exhaust emission. Furthermore, the proposed plug associated with a capacitor discharge ignitor (CDI) is able to ignite an engine system effectively, overcoming the disadvantage of long charging time caused from a traditional inductive discharging ignition (IDI). Thus, it has the particular feature of saving energy and is an eco-friendly product. To verify the proposed research, simulated waveforms and experimental results will be illustrated and explained in this thesis.
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20

Mirza, Salma. "Scalable, Memory-Intensive Scientific Computing on Field Programmable Gate Arrays". 2010. https://scholarworks.umass.edu/theses/404.

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Cache-based, general purpose CPUs perform at a small fraction of their maximum floating point performance when executing memory-intensive simulations, such as those required for many scientific computing problems. This is due to the memory bottleneck that is encountered with large arrays that must be stored in dynamic RAM. A system of FPGAs, with a large enough memory bandwidth, and clocked at only hundreds of MHz can outperform a CPU clocked at GHz in terms of floating point performance. An FPGA core designed for a target performance that does not unnecessarily exceed the memory imposed bottleneck can then be distributed, along with multiple memory interfaces, into a scalable architecture that overcomes the bandwidth limitation of a single interface. Interconnected cores can work together to solve a scientific computing problem and exploit a bandwidth that is the sum of the bandwidth available from all of their connected memory interfaces. The implementation demonstrates this concept of scalability with two memory interfaces through the use of available FPGA prototyping platforms. Even though the FPGAs operate at 133 MHz, which is twenty one times slower than an AMD Phenom X4 processor operating at 2.8 GHz, the system of two FPGAs performs eight times slower than the processor for the example problem of SMVM in heat transfer. However, the system is demonstrated to be scalable with a run-time that decreases linearly with respect to the available memory bandwidth. The floating point performance of a single board implementation is 12 GFlops which doubles to 24 GFlops for a two board implementation, for a gather or scatter operation on matrices of varying sizes.
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21

Τζινευράκης, Αντώνιος. "Συμβολή στην ανάλυση του ηλεκτρικού και του μαγνητικού πεδίου στο περιβάλλον εναερίων γραμμών ηλεκτρικής ενέργειας". Thesis, 2009. http://nemertes.lis.upatras.gr/jspui/handle/10889/2467.

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Η παρούσα διδακτορική διατριβή αποτελεί μια συμβολή στην ανάλυση του ηλεκτρικού πεδίου στο περιβάλλον εναέριων γραμμών απλού και διπλού κυκλώματος. Αναπτύσσονται αναλυτικές σχέσεις για τον ακριβή υπολογισμό της έντασης του ηλεκτρικού πεδίου καθώς και απλούστερες προσεγγιστικές σχέσεις. Η προτεινόμενη μέθοδος υπολογισμού προέκυψε από τον συνδυασμό της ανάλυσης των φορτίων των αγωγών σε συμμετρικές συνιστώσες, της περιγραφής της έντασης του ηλεκτρικού πεδίου με διπλούς μιγαδικούς αριθμούς και της χρήσης του αναπτύγματος πολυπόλων για την έκφραση της έντασης του ηλεκτρικού πεδίου. Με τους διπλούς μιγαδικούς αριθμούς επιτυγχάνεται η παράσταση με μιγαδικούς αριθμούς τόσο των χρονικά ημιτονοειδώς μεταβαλλόμενων μεγεθών (τάσεων και φορτίων) όσο και των γεωμετρικών αποστάσεων. Το ανάπτυγμα πολυπόλων είναι μια σειρά απείρων όρων, όπου ο κάθε επόμενος όρος είναι αντιστρόφως ανάλογος της αυξανόμενης δύναμης της απόστασης. Αναπτύσσονται επίσης ακριβείς αναλυτικές σχέσεις, καθώς και απλούστερες προσεγγιστικές σχέσεις, για τον υπολογισμό της μαγνητικής επαγωγής γραμμών διπλού κυκλώματος. Για την ανάπτυξη των σχέσεων αυτών συνδυάζεται η χρήση των διπλών μιγαδικών αριθμών με το ανάπτυγμα πολυπόλων για την έκφραση της μαγνητικής επαγωγής.
This thesis is a contribution to the analysis of the electric field in the vicinity of single-circuit and double-circuit overhead power lines. Analytical formulas are developed for the accurate calculation of the intensity of the electric field as well as simpler approximate formulas. The proposed calculation method has arisen from the combination of the analysis of the conductors’ charges in their symmetrical components, the description of the intensity of the electric field using double complex numbers and the use of multipole expansions to express the intensity of the electric field. The use of double complex numbers allows the simultaneous representation of sinusoidal varying quantities (voltages and charges) and geometrical distances with complex numbers. The multipole expansion is a series of infinite terms, where each term is inversely proportional to an increasing power of the distance. Accurate analytical formulas are also developed as well as simpler approximate formulas for the calculation of the magnetic flux density produced by double-circuit lines. For the development of those formulas the use of double complex numbers is combined with the multipole expansion to express the magnetic flux density.
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