A precision measurement of the d(gamma ,n)p reaction was performed at the High Intensity gamma-ray Source (HIGS), which is located at the Duke Free Electron Laser Laboratory on the campus of Duke University. The gamma-ray beams were nearly 100% linearly polarized, allowing the angular distributions of both the analyzing power and unpolarized cross section to be measured at 14 and 16 MeV. The photons were incident on a heavy water target and the neutrons from the photodisintegration reaction were detected using the Blowfish detector array, which consists of 88 liquid scintillator detectors with large angular coverage.A transition matrix element (TME) analysis was performed on the data which allowed the amplitudes of the TMEs which contribute to the reaction at these energies to be extracted. This was done by invoking Watson's theorem, which fixes the relative TME phases using the n-p scattering phase shifts, leaving the TME amplitudes as free parameters in fits to the data. The results indicated very good agreement with a recent potential model calculation for the amplitudes of the three electric dipole (E1) p-waves, which account for over 90% of the cross section at these energies.The extracted TME amplitudes were then used to construct the observable which enters into the Gerasimov-Drell-Hearn (GDH) Sum Rule integrand. The results are the first experimental indication of a positive value of the GDH integrand in the region near photodisintegration threshold. A positive value at these energies has been shown by theory to be due to relativistic contributions. / Dissertation

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Made available in DSpace on 2015-04-15T12:50:25Z (GMT). No. of bitstreams: 1 303818.pdf: 559380 bytes, checksum: f7bfdfb49822ed168302226c1f88bf15 (MD5) Previous issue date: 2006-06-22 / The dissertation To hear and to love Iahweh: Dt 6,4-9, a way towards a culture of peace is an exegetic biblical-pastoral study of the pericope of Deuteronomy 6,4-9, which is called Shem? Israel, which is the challenge faced by Israel of listening and accepting Iahweh as the only God in response to His love and fidelity. His attitude should be of loving Him with all his heart, with all his soul and with all his strength and to inculcate into the children these teachings. Such demonstration of love towards Iahweh and not towards other gods, leads Israel to organize a society based not in violence or social classes, but determined by fraternal structures. In our times, the recuperation of these actions express values such as solidarity, cooperation and fraternity that have been abandoned throughout history, causing situations of violence. The Kings Hezekiah and Josiah, in the VIII and VII centuries B.C., favored reforms aiming at uniting Israel around the unique God, the unique people, the unique land, an unique sanctuary and a unique Law, to keep the nation strong and united. During that period they found in the Temple the Book of the Law that was used as the basis for those reforms. This book is part of the present Deuteronomy in which the Shem? Israel works as a set of values such as solidarity, fraternity, and justice that helps to build up actions towards peace. In our days, in the middle of conflicts and dehumanization, the Shem? is presented as an alternative way to recognize the signs already existent in our society, that focus on the construction of a culture of peace. It points towards a social change in the perspective of a communitarian solidarism, having the Jesus complement in the commandment to love your neighbor as yourself, becoming a fundament for attitudes that consolidate traditions of peace. / A disserta??o Ouvir e amar a Jav?: Dt 6,4-9, um caminho para a cultura de paz ? um estudo exeg?tico b?blico-pastoral da per?cope de Deuteron?mio 6,4-9, que ? denominado de Shem? Israel, sendo Israel desafiado a ouvir e a reconhecer Jav? como ?nico Deus em resposta de amor e fidelidade. A atitude de Israel deveria ser de am?-lo com todo o cora??o, com toda a alma e com toda a for?a e inculcar aos filhos estes ensinamentos. Esta demonstra??o do amor evidenciado unicamente por Jav?, e n?o por outros deuses, leva Israel a formar uma sociedade em que a organiza??o n?o se ap?ia na viol?ncia, nem se estratifica em classes sociais, mas ? determinada por estruturas fraternas. Atualmente, o resgate destas a??es expressa valores como a solidariedade, a coopera??o e a fraternidade que foram minimizados no decorrer da hist?ria, ocasionando situa??es de viol?ncia. Os reis Ezequias e Josias, no s?c VIII e VII a.E.C., promoveram reformas religiosas e pol?ticas com o objetivo de unir Israel em torno de um s? Deus, um s? povo, uma s? terra, um s? santu?rio e uma s? lei, a fim de manter a na??o forte e coesa. Neste per?odo, foi encontrado, no Templo, o livro da Lei que serviu como base para estas reformas. Este livro comp?e o Dt atual, em que o Shem? Israel ? agregador de valores como a solidariedade, a fraternidade e a justi?a que impulsionam a??es de paz. Na contemporaneidade, em meio aos conflitos e desumaniza??es, o Shem? ? apresentado como um caminho alternativo, possibilitando reconhecer sinais existentes na sociedade, que enfoca a forma??o de uma cultura de paz. O Shem? aponta para uma mudan?a social na perspectiva do comunitarismo solid?rio, onde o complemento de Jesus Cristo em amar?s o teu pr?ximo como a ti mesmo (Mc 12,31), ? fundamento de atitudes que consolidam tradi??es de paz.

<p>Reaction cross sections were measured for protons at 65.5 MeV, for deuterons at 37.8, 65.5, 97.4 MeV, for ³He at 96.4, 137.8, 167.3 MeV, and for ⁴He at 69.6, 117.2, 163.9 and 192.4 MeV. Targets were ⁹Be, ¹²C, ¹⁶O, ²⁸Si, ^40,48Ca, ^58,60Ni, ^{112,116,118,120,124}Sn and ²⁰⁸Pb. ⁴⁸Ca and ¹¹⁸Sn targets were used only for some of the measurements. Rest of the targets have been measured for all energies and projectiles but ⁴He at 69.6 MeV where reaction cross sections were measured for ⁹Be, ¹²C, ¹⁶O, ²⁸Si, ⁴⁰Ca targets. A modification of a standard attenuation technique was used. Details of the experimental design are presented.</p><p>Experimental uncertainties were 2-3% for p, 3% for d and 3-10% for ^3,4He. </p><p>A strong forward peaking of the reaction products was observed for ^3,4He. Therefore the standard reaction cross section measurement technique was not applicable for these projectiles. The forward peaking is also responsible for the increase of experimental uncertainties for these projectiles. The forward peaking of the reaction products is not known for other projectiles and has also not been observed with ^3,4He at different - both higher and lower - energies. Possible explanations for this phenomenon are discussed.</p><p>Optical model calculations of the reaction cross sections are in good agreement with the measured values.</p><p>The measurements were performed with beams from the Gustav Werner cyclotron at the The Svedberg Laboratory, Uppsala.</p>

Reaction cross sections were measured for protons at 65.5 MeV, for deuterons at 37.8, 65.5, 97.4 MeV, for 3He at 96.4, 137.8, 167.3 MeV, and for 4He at 69.6, 117.2, 163.9 and 192.4 MeV. Targets were 9Be, 12C, 16O, 28Si, 40,48Ca, 58,60Ni, 112,116,118,120,124Sn and 208Pb. 48Ca and 118Sn targets were used only for some of the measurements. Rest of the targets have been measured for all energies and projectiles but 4He at 69.6 MeV where reaction cross sections were measured for 9Be, 12C, 16O, 28Si, 40Ca targets. A modification of a standard attenuation technique was used. Details of the experimental design are presented. Experimental uncertainties were 2-3% for p, 3% for d and 3-10% for 3,4He. A strong forward peaking of the reaction products was observed for 3,4He. Therefore the standard reaction cross section measurement technique was not applicable for these projectiles. The forward peaking is also responsible for the increase of experimental uncertainties for these projectiles. The forward peaking of the reaction products is not known for other projectiles and has also not been observed with 3,4He at different - both higher and lower - energies. Possible explanations for this phenomenon are discussed. Optical model calculations of the reaction cross sections are in good agreement with the measured values. The measurements were performed with beams from the Gustav Werner cyclotron at the The Svedberg Laboratory, Uppsala.

Techn. University, Diss., 2006--Darmstadt.

Made available in DSpace on 2014-12-17T15:14:55Z (GMT). No. of bitstreams: 1 RooseweltFS_DISSERT.pdf: 3975312 bytes, checksum: 63a58c8e9991d4e260aa50d3b1e14e27 (MD5) Previous issue date: 1993-03-05 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / O vidro de spins de Ising com intera??es de alcance infinito (modelo Sherrington Kirkpatrick), na presen?a de um campo magn?tico aleat?rio distribu?do segundo uma lei de probabilidades gaussiana, ? investigado pelo m?todo das r?plicas. Na aproxima??o de simetria entre r?plicas, a fronteira cr?tica que separa as duas fases poss?veis, Ferromagn?tica (F) e Independente (I), ? determinada. A an?lise de estabilidade de Almeida Thouless ? efetuada e as regi?es de instabilidade da solu??o de simetria entre r?plicas s?o encontradas: I (parte inst?vl da parte I) e F (PARTE INST?VEL DA FASE f). Tais regi?es podem ser identificadas respectivamente, com as fases de vidro de spins e ferromagn?tica mista do modelo Sherrington Kirkpatrick

The heaviest fragments, recoils, have been studied in proton and deuteron induced 28Si reactions and proton-20Ne reactions at 100-300 MeV per nucleon. Inclusive charge and angular distributions and coincidences between He nuclei and recoils have been compared to two theoretical models, Dubna Cascade Model and JAERI Quantum Molecular Dynamics. The overall agreement was good for the reactions with 28Si, however the angular distributions of He fragments could not be reproduced. For the 20Ne reactions the recoil angular distributions were only reproduced for large angles. There was a significant underestimation at small angles and low recoil charge. α-clustering in the bombarding nucleus is a possible explanation for the deviations. In the 100 MeV per nucleon reactions all assumptions of the models may not be valid and the agreement was worst for these reactions. In proton-natXe reactions intermediate mass fragments have been studied from 200 to 1400 MeV. Slow ramping was used to scan the energy. Charge distributions and a caloric curve have been compared to Cascade Fragmentation Evaporation Model. Charge distributions showed good agreement for fragments with Z&lt;8 but the heavier fragments were underestimated.

Radionuclide production is always the first step of radiopharmaceutical research. The production of n.c.a.197Hg together with the short-lived 197mHg isomer is possible by proton or deuteron irradiation of natural gold using a cyclotron, as two promising nuclear reactions reported: 197Au(p,n)197(m)Hg reaction, 197Au(d,2n)197(m)Hg reaction. The access to n.c.a. 197(m)Hg should be in sufficient quantity and quality so as to be suitable for analytical studies and labeling studies with small scale and for animal and other preclinical studies on large scale. Moreover, an improved design by studying irradiation time and energy will provide the facility with sufficient quantity and quality for imaging and experimental therapeutically purposes. The development of a rapid, reliable method for Hg/Au separation represents an important prerequisite for increasing yields which will obtain 197(m)Hg in higher activity level with the product elution into a small volume. Here, many of previously established methods for mercury separation should be employed, such as distillation of the metal, extraction by organic solvents, extraction by resin, etc. However, owing to the different mechanisms, these separations do not always give satisfactory results. The purity and the final volume of product, efficiency, automatization and total processing time of separation procedure, these factors are extremely important for the next coming labeling studies. Therefore, comparison studies need to be employed to select the most suitable method enable for labeling studies. Establishing strategies for development of 197(m)Hg labeled in vivo stable labeling units. Several ready-to-use chelators are urgent needed before 197(m)Hg labeling unit conjugated with any specific targeted molecules. Numerous factors need to be considered for the development of the agents: Firstly, a robust synthetic and labeling strategy should be developed for the chelators or precursors of 197(m)Hg. Secondly, it should be strongly stable (especially bio-stability) to avoid the accumulation of radioactive substances in non-target organs. Thirdly, water solubility should be high enough for animal administration and avoid the toxicity of organic solvent. Fourthly, high selectivity (specificity) to avoid the transchelation/side reaction(s) with other metal ions. There are mainly two different approaches for 197(m)Hg labeling, first kind of ligands are based on Hg-S bonds, which form 197(m)Hg-S based compounds. It is well known that mercury shows strong ability on chelating of thiols, dithiols, disulfide, sulfur based and other sulfur rich interacting ligands, which shows great potentials for 197(m)Hg labeling. Thus, thiol based chelators should be investigated in the thesis. 197(m)Hg-organometallics was the second. Mercury is unique among metals in its capability to form covalent Hg-C bonds and has its own organic chemistry because the existence of large numbers of organic Hg compounds, which shows great potential to be labeled and applied in the field of radiopharmacy. After synthesizing novel agents, its theranostics capability should be accessed by a series of in vitro and in vivo studies. Depending on the type of different agents, the radiolabeling strategies should be optimized. Soon afterwards, detailed analytical and in vitro characterization with high-performance liquid chromatography (HPLC), radio thin-layer chromatography (radio-TLC), among other methods should be performed to determine several radiochemical behaviors such as labeling efficiency and stability. Besides, for the purpose of in vivo animal studies, removal of organic solvents and well-suited methods for purification of the radiolabeled units should be developed if necessary. Then, the most promising radiolabeled compounds were selected for further pharmacokinetic studies in rats. In vivo SPECT imaging studies should be employed for further investigations of radiopharmacological behaviors.