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Thesis (Ph.D.)--Boston University / PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / The present work involves the study of a simplified atomic system to gain better understanding of controlling and manipulating Rydberg-like systems. Detailed simulations of the classical hydrogen atom have been carried out using, first, the nonrelativistic Lorentz-Dirac classical equation of motion for a charged point particle under the action of a Coulombic binding force, plus applied radiation, then progressing to include the effects of the classical electromagnetic zero-point (ZP) radiation spectrum. This work has been carried out under the guide of the theory called stochastic electrodynamics (SED). Many applications involving atoms in excited Rydberg states can be developed, based on the work described here, to aid in carefully controlled thin film deposition, ion implantation, etching, and sputtering in micro and nanoelectronics, as well as optical instrumentation related applications, via applied electromagnetic fields. The improved simulation code for the long-term numerical integration of non-linear differential equations for tracking particles, should be helpful for a number of other closely related areas. Specifically, investigations into astronomy, including the Kepler problem treated in satellite and planetary orbit simulations in celestial mechanics, as well as problems in such areas as atomic and molecular dynamic studies, may well find benefit from the investigations here. As shown in the present study, very nonlinear behavior occurs for such Rydberg-like system, making a numerical study of the system nearly essential. Little of this work has been explored before in the literature. Resonances, rapid transitions, very long decay times, all influenced by applied radiation, are described and analyzed in detail here. Such results are expected to have significant bearing on recent experiments reported in the literature on "kicked Rydberg" atoms. Moreover, as reported here, the ZP field was included in very lengthy numerical simulations, resulting in a very close comparison with the ground state of hydrogen as predicted by Schrodinger's wave equation. This last result helps to support SED in general, although certainly considerable more work needs to be done for a full confirmation, but in the process this result greatly aids simulating situations where SED is expected to hold very well. / 2031-01-01

In this study, it was experimentally proved, for the first time, that it is possible to predict the frequency of electromagnetic radiation that can modulate activity of proteins and more specifically activity of enzymes. The prediction was obtained using the computational model so called the Resonant Recognition Model (RRM). The model was tested here experimentally using the reaction catalysed with the enzyme l-lactate dehydrogenase (LDH). The RRM model was applied to the group of the enzymes belonging to the sub-subclass EC 1.1.1.27 i.e. l-lactate dehydrogenase. The wavelengths of the electro magnetic radiation calculated by the RRM and proposed to alternate activity of l-lactate dehydrogenate were identified at =620 25 nm and =840 25 nm. Enzyme activity was then measured after the exposure to the low-intensity, electromagnetic radiation (EMR) within the proposed EMR range [560-860 nm]. The experimental results have indeed shown that there is a significant increase in the activity of LDH only after irradiation within the range of the frequencies predicted by the RRM: 596nm (12%; P less than 0.001) and 829 nm (11.8%, P less than 0.001). These results prove successfully that activity of proteins and more specifically enzymes could be modified by EMR radiation of specific frequencies and even more that RRM computational model can successfully predict these frequencies.

Στην παρούσα εργασία μελετήθηκε η επίδραση της ηλεκτρομαγνητικής ακτινοβολίας 960 ΜHz σε ποιοτικά και βιολογικά δραστικά συστατικά του οίνου. Συγκεκριμένα τα δείγματα του οίνου εκτέθηκαν σε ακτινοβολία 960 ΜHz επί 3 και 5 ημέρες, επί 15 και 30 min, σε αποστάσεις 20 και 40 cm, ενώ όλες οι ακτινοβολίες πραγματοποιούνταν ανά 24 ώρες. Μετά την έκθεση των δειγμάτων στο συγκεκριμένο πεδίο έγιναν οι ακόλουθοι προσδιορισμοί: • Ολική οξύτητα • pH • Πολυφαινόλες • Ολικό θειώδες • Απόχρωση χρώματος • Ένταση χρώματος • Ασκορβικό οξύ Από τα αποτελέσματα των παραπάνω προσδιορισμών συμπεραίνουμε :  Υπάρχει, στατιστικά σημαντική μείωση των τιμών της οξύτητας του οίνου, σε όλα τα δείγματα που ακτινοβολήθηκαν.  Δεν παρουσιάστηκαν στατιστικά σημαντικές μεταβολές στις τιμές του pH.  Παρουσιάζεται στατιστικά σημαντική μείωση των τιμών των πολυφαινολών στα δείγματα που εκτέθηκαν στην απόσταση των 20 cm ανεξαρτήτως των λεπτών και των ημερών έκθεσης ενώ δεν παρατηρείται στατιστικά σημαντική μεταβολή στα δείγματα που εκτέθηκαν σε απόσταση 40 cm.  Επίσης, στα δείγματα που εκτέθηκαν στην απόσταση των 20 cm παρατηρήθηκε στατιστικά σημαντική μείωση των τιμών του ολικού θειώδους σε αντίθεση με τα δείγματα που εκτέθηκαν στην απόσταση των 40 cm όπου δεν παρατηρήθηκαν στατιστικά σημαντικές μεταβολές.  Δεν παρουσιάστηκαν στατιστικά σημαντικές μεταβολές στις τιμές της απόχρωσης και της έντασης του χρώματος του οίνου.  Παρατηρήθηκε στατιστικά σημαντική αύξηση των τιμών του ασκορβικού οξέος σε όλα τα ακτινοβοληθέντα δείγματα. Συμπερασματικά, θα μπορούσαμε να αναφέρουμε πως η ηλεκτρομαγνητική ακτινοβολία που παράγεται μέσω κινητού τηλεφώνου μπορεί να επηρεάσει ποιοτικά χαρακτηριστικά του οίνου, εφόσον ο οίνος παράγεται ή αποθηκεύεται σε χώρους που μπορεί να βρίσκονται σε κοντινή απόσταση από πηγές τέτοιας μορφής ηλεκτρομαγνητικής ακτινοβολίας. / The effects of electromagnetic radiation of 960 MHz on the qualitative and biological effective substances of wine were studied. Certain samples of wine were exposed to 960 MHz of EMFs for 3 or 5 successive days duration 15 or 30 min at distances from the antenna of the electromagnetic devise, of 20 and 40 cm. After the expose were studied the following: • Total acidity • pH • Determination of the polyphenols • Sulphite total • Shade of color wine • Color intensity wine • Ascorbic acid Analysis of the wine samples after EMF expose revealed:  Statistical significant decrease of the acidity of the wine in all samples.  No changes on the pH of the samples.  Statistical significant decrease of the levels of polyphenols at distance of expose of 20 cm in all samples, but no effect at samples exposed at distance of 40 cm.  Statistical significant decrease of the levels of sulphite total in all samples exposed at distance of 20 cm but not significant changes at samples at distance of 40 cm.  There was no significant change on the values of shade of color wine and color intensity wine.  Statistical significant increase on values of ascorbic acid in all the exposed samples. In conclusion our results show that expose to electromagnetic fields of mobile phones can change certain qualitative and biological acting substances of wine, when the wine exposed at short distances (20 and 40 cm) of the EMF of the mobile phones.

Thesis (M.S. in Electrical Engineering) Naval Postgraduate School, June 1997. / Thesis advisors, Richard W. Adler, Jovan E. Lebaric. Includes bibliographical references (p. 45). Also available online.

<p> When a beam of electromagnetic radiation, limited by an aperture, undergoes total internal reflection, a sideways displacement of the reflected beam results. This displacement is known as the Goos-Hänchen Shift. </p> <p> In this work the Goos-Hänchen Shift is studied with 3.2 cm microwaves. The observed shifts disagree with three existing theories. For this reason a modified theory is developed in this work. The throey regards the beam from a pyramidal horn antenna as a superposition of a large number of plane waves. The shift is calculated on this basis. Agreement between experiment and theory is good. </p> / Thesis / Doctor of Philosophy (PhD)

<p> A measurement of the cross section for the interaction of electromagnetic radiation with matter has been undertaken. Total cross sections for 29 photon energies from 121 keV to 10.8 MeV in 9 target elements from carbon to uranium have been realized and pair production cross sections, for energies above 2 MeV, deduced from the results. A direct measurement of the partial pair cross section for photons with energies from 1120 to 2754 keV in 6 target elements from titanium to lead has also been included.</p> / Thesis / Doctor of Philosophy (PhD)

>Magister Scientiae - MSc / Physics is the study of natural phenomena. Nuclear physicists have since the discovery of the nucleus been working on understanding its dynamics. The nuclear chart, analogous to the periodic table of elements, is illustrated in Fig. 1.1 and color coded according to decay modes. Several theoretical models, based on various hypothesis, have been developed during the years in order to understand nuclear phenomena such as nucleon-nucleon (n-n) interactions, binding energies, radii, excited states, etc. Unfortunately, no-unique model is actually able to grasp all nuclear phenomena at the desired level of accuracy. Among the di erent models, we notice that two distinct hypotheses can be used to describe nuclear properties. Firstly, the independent particle shell model (IPSM) + the n-n residual interaction, which assumes that a nucleon moves independently in a potential generated by other nucleons. Secondly, the macroscopic models, where a nucleus is considered as a whole, i.e. neutrons and protons behave cooperatively and are mutually coupled to each other; highlighting the short-ranged character of the nuclear force. The liquid-drop model is an example of such macroscopic models. Re nement of these models is dependent on experimental observations that are better detailed for nuclei along the line of - stability, making up a small fraction of the known isotopes, as shown in Fig. 1.1. In practice, various techniques for studying exotic nuclei up to neutron and proton drip-lines have been devised, including the use of radioactive ion beams. However, the main challenges are the synthesization and short lived periods of these exotic nuclei resulting in insu cient data collection from which the characteristics and structural information are extracted. In general, nuclei have unique structures represented by a particular con guration as given by the shell model (SM). These structures impact a number of physical quantities, e.g. transition probabilities, cross sections and photon-strength functions. Experimental methods such as Coulomb excitation or electromagnetic radiation are used to probe these structures without invoking the nuclear force.

Por conta da liberação de uma nova faixa de espectro as aplicações que utilizam transmissão em banda ultralarga se expandiram. Por conta disso, várias formas de transmissão pulsada ganharam destaque. Contudo, o projeto e estudo de antenas até então era majoritariamente feito em banda estreita e regime permanente senoidal. Além disso, para transmissão pulsada, a resposta impulsiva da antena passa a ser mais necessária do que sua resposta em banda estreita. Por isso, o objetivo desse estudo foi explorar o que ocorre com pulsos estreitos se propagando em uma antena de forma a se obter uma aproximação da resposta impulsiva de antenas. Mais especificamente, foi obtido um modelo analítico que explicita a relação entre a geometria e o funcionamento da antena. Através do estudo da espiral equiangular foi possível encontrar o decaimento do pulso de corrente ao longo da linha como também o campo radiado de forma quantitativa. Tal resultado, assim como os procedimentos para sua obtenção, poderá ser utilizado para outras antena filamentares. / The applications for Ultra Wide Band have grown since the new regulation allowed the use of a new large frequency band. Since then, systems for pulsed transmission entered the spotlight. However, the antenna\'s project and study were in big part done in narrowband and sinusoidal steady-state. Besides, the impulse response is of much more interest for these systems than the frequency response. For this reason, the main goal of this work is to explore how current pulses propagate on the antenna to obtain an approximate impulse response. Moreover, an analytical model that unveils the relation between the antenna geometry and its current decay is presented. Through the study of the equiangular spiral it is possible to find the pulse decay as a function of the line length and the radiated field in a quantitative fashion. This result as well as the methods used to obtain it can be used for other antennas.

Este trabalho de tese de doutorado visou identificar as matérias primas naturais produzidas no Brasil e possíveis de serem utilizadas na produção de concretos de elevada massa específica. Desenvolver uma metodologia para a caracterização, preparo, moldagem, ensaios para determinação do coeficiente de atenuação linear experimental, calculo do coeficiente de atenuação linear teórico, e determinação do Z efetivo, culminando com a confecção de um banco de dados embrionário para os concretos de elevada massa específica preparados com matérias primas nacionais. Para tanto foram identificadas onze matérias primas produzidas no Brasil com caracteísticas adequadas para a produção de concretos de elevada densidade. Apresentamos os fundamentos teóricos ao bom entendimento do trabalho tanto no campo da proteção radiológica como naquela dos conceitos que podem ser usados para a produção de blindagem às radiações gama e X. Preparamos vinte e dois tipos de concretos de elevada massa específica com a utilização de matérias primas naturais e nacionais. Os concretos desenvolvidos foram preparados, moldados e ensaiados com uma fonte de 137Cs, de 3,7 1010 Bq (1Ci) de atividade. Foram calculados os coeficientes de atenuação linear com a utilização das análises químicas dos concretos preparados e encontrados os coeficientes de atenução linear experimentais para comparação e avaliação da técnica proposta. Foram medidas as massas específicas dos concretos preparados em virtude de sua importância para a formação da seção de choque do composto quando da predominância do efeito Compton, e determinado o Z efetivo para a região predominante do efeito fotoelétrico. Por fim foram calculados os custos de produção levando-se em conta somente os custos das matérias primas. Para as massas específicas os concretos apresentaram uma variação de 2,74 kg/dm3 até 3,76 kg/dm3, já para o coeficiente de atenuação linear experimental a variação foi de 0,2137 cm-1 a 0,2860 cm-1, o Z efetivo variou de 19 a 25. Finalizando o trabalho foram discutidos os resultados e sugeridos preferências de concretos para utilização em blindagens com a aplicação de alguns conceitos. Comparando os resultados encontrados com vários outros publicados em trabalhos internacionais, verificamos o grau de similaridade. / This PhD thesis the natural raw materials produced in Brazil and in the production of high density concrete. Furthermore, we also develop a methodology for characterization, preparation, molding, testing to determine the linear attenuation coefficient of experimental, theoretical calculation of the linear attenuation coefficient, and determination of the effective Z, culminating with the production of an embryo stock data for the specific high density prepared with local raw materials. For this, we identified eleven raw materials produced in Brazil with suitable characteristics for the production of high density concrete. We present the theoretical understanding of radiological protection and in the fundamental concepts that can be used to produce shielding for gamma and X radiation. During the work, we prepared twenty-two concrete types of high specific weight, with the use of natural materials and domestic materials. These new concretes were prepared, molded and tested with a Cs-137 source (3.7.1010 Bq (1Ci) activity). The linear attenuation coefficients were calculated employing the chemical analyzes of the prepared concrete and the experimental linear attenuation coefficients were also determined for comparison and evaluation of the proposed technique. The specific masses of the concrete samples were determined, given their importance to the cross section for the Compton Effect predominance. The effective Z was also determined were the photoelectric effect was predominant. Finally, the production costs were considered, taking into account only the cost of the raw materials. For the specific masses, the concretes presented a variation from 2.74 kg/dm3 to 3.76 kg/dm3. In the case of the experimental linear attenuation coefficient the variation was from 0.2137 cm-1 to 0.2860 cm-1, and the effective Z varied from 19 to 25. As conclusion, the results were discussed e the preferred concretes for the shielding purposes were suggested. Comparing the results with other published international work, we find the degree of similarity.