Dissertations / Theses on the topic 'Published in N.Z as'

In this thesis, I present my published works in the broad field of medical microbiology. Over a period of thirty years I have worked in a range of settings,. including hospital and public health laboratories, major reference laboratories and academic science departments. I have studied significant public health issues associated with each position, and therefore, while there is no single theme in my work, the emphasis of my research has been very much on the development and validation of methods and their application to public health microbiology. My early work was on obligately anaerobic bacteria. I began to study Clostridium difficile during my doctoral research and continued for several years after I completed my PhD. My expertise in anaerobic microbiology led to several book chapters and ultimately to an undergraduate textbook and an edited volume on anaerobic microbiology methods. My work on anaerobic bacteria forms one of three themes in my commentary. During my tenure at the University of Ulster; I began to broaden my research to encompass pathogens in the environment. Areas of interest included the survival of pathogenic bacteria during anaerobic digestion of cattle slurry and the anaerobic bacterial flora of flax retting. I moved to the University of West Indies in Barbados, where for 13 years I taught microbiology to medical students and provided clinical microbiology support to the hospital and public health laboratories. This venue provided me with the opportunity to follow a diverse research agenda, with a strong concentration on diseases of local and regional public health importance. I have included some of this work in my third commentary theme, clinical and public health microbiology. My major contributions to the field have undoubtedly been in the diagnosis, taxonomy and epidemiology of leptospirosis. I began working on leptospirosis in 1992 in the former Medical Research Council laboratory in Barbados. My work here included both serological and molecular diagnostic studies, and epidemiological research on reservoir animals and other zoonotic diseases. After moving to the Centers for Disease Control and Prevention (CDC), my work was focussed on developing tools for molecular diagnosis and molecular typing of leptospires and on taxonomy of leptospires. At the CDC, I was also the Acting Chief of the Special Bacteriology Reference Laboratory. In this capacity, I had the opportunity to lead a group focussed on the identification and characterization of previously unrecognised bacterial pathogens. Some of this work is included in my third commentary theme. I moved to Saskatchewan in 2003, to my current position in the provincial public health laboratory. My research in Saskatchewan has been directed towards the use of molecular techniques for diagnosis and epidemiological typing of significant public health pathogens, while mentoring younger scientists. Community-acquired methicillin-resistant Staphylococcus aureus is a public health challenge in our communities and I have made significant contributions to a collaborative effort to understand and control these infections in Saskatchewan. In recent years I also have assumed a leadership role in biosafety and biosecurity regulatory issues and in quality assurance and proficiency testing. An abbreviated copy of my curriculum vitae is included to provide an indication both of the range of my research work and my other contributions to the field. In the interests of brevity, papers presented at conferences and published abstracts are not included.

É mostrada a obtenção do Hamiltoniano Quântico Unidimensional associado a um modelo de Mecânica Estatística Clássica de simetria Z(N)xZ(N). O cálculo do Estado Fundamental deste Hamiltoniano é feito através do cálculo da energia livre do modelo de mecânica estatística, sendo que esta, por sua vez, é calculada utilizando-se Equações Funcionais advindas da equação dos triângulos (o método de slução é explanado em detalhes). Este tipo de cálculo foi feito originalmente por Baxter para N=2, sendo que neste caso o modelo de mecânica estatística é conhecido por 8-vértices e o Hamiltoniano quântico associado é o XYZ (Heisenberg completamente anisotrópico). Neste presente trabalho, o Hamiltoniano é obtido formalmente para as demais simetrias (qualquer N) ao incrementar-se o cálculo feito por Baxter com um novo método que torna possível esta generalização. Como exemplos, são feitos cálculos detalhados para N=3, em um limite em que as funções envolvidas na solução do problema de mecânica estatística tornam-se trigonométricas. O limite citado é análogo ao que se faz para N=2 quando do modelo de 8-vértices obtém-se o modelo de 6-vértices e o Hamiltoniano associado torna-se o XXZ (Heisenberg anisotrópico). Além da obtenção do Hamiltoniano é mostrada a dualidade do modelo Z(N)xZ(N). Também aqui este resultado foi obtido pela primeira vez por Baxter, apenas para o caso N=2, usando uma maneira gráfica que não permitiria a generalização para as outras simetrias. O método aqui apresentado, além de simplificar o resultado para N=2 é feito para todo N<br>The one-dimensional quantum Hamiltonian associated to a classical statistical mechanical model with Z(N)xZ(N) symmetry is obtained. The calculation of the Ground state of this Hamiltonian is performed via the calculation of the Free energy of the statistical mechanical model, which in its turn, is calculated by the functional equations originated from the Triangle equations. This type of calculation has been originally performed by Baxter for N=2, in which case the statistical mechanical model is known as the 8-vertex and the associated Quantum Hamiltonian is the XYZ (Completely anisotropic Heisenberg Model). In the present work the Hamiltonian is formally obtained for any N upgrading Baxter´s calculation by the use of a new method which allows its generalization. As an example, detailed calculations for N=3 are performed on a limit in which the functions arising from the triangle equations become trigonometric. This limit is analogous to the case N=2 when the 6-vexter model is obtained from the 8-vexter and the associated Hamiltonian become the XXZ (Anisotropic Heisenberg Model). Besides the obtained of the Hamiltonian, the duality of the Z(N)xZ(N) model is also shown. This result was demonstrated by Baxter only for the case N=2 by means of a graphic method which does not allow generalization for a arbitrary N. The method present in this work, besides the simplification of the result for N=2, is valid for any N

The N/Z, or ratio of neutron to proton, degree of freedom may be used to study intermediate energy nuclear collisions to give information about the origin of emitted collision fragments. Establishing under what conditions the onset of N/Z equilibrium occurs will give a better understanding of the physics of the equation of state through the use of simulation codes. If the nuclear equation of state can be elucidated in terms of the N/Z dependent component and how the N/Z dependent component varies with density, then the equilibrium ratio of protons to neutrons inside high density neutron stars can be inferred, allowing for prediction of cooling rates and supernovae mechanisms. In the current study, isotopic and isobaric ratios at thetalab=40o with cuts of 10% and 20% most central events, respectively, are studied for their N/Z equilibration signals. Light charged particles, or LCPs, are found to be emitted from systems which have not yet fully N/Z combined; the fragments with A=3 are emitted from the least equilibrated systems. Intermediate mass fragments, or IMFs, are seen to be emitted by N/Z equilibrated sources, within statistical error bars. The N/Z tracer method is used with ratios of isotopes and isobars to see how the amount of nuclear stopping or N/Z mixing changes as a function of the centrality of the event. The N/Z observable is used to reinvestigate earlier findings of the isotope and isobar ratio observables and shows the progression (or lack of it, in some cases) of the N/Z equilibration. This observable has proven to be a clear and sensitive tool to use when considering the differences in N/Z mixing of the systems at two energies.

This thesis presents new deep near-infrared imaging data in one of the most well studied regions of the sky, the Great Observatories Origins Deep Survey's northern field (GOODS-N). In particular, we have produced a science grade Ks-band (2.2 μm) source catalogue with a depth of KS(AB) = 23.8 magnitudes. With our K-selected sample, we use the BzK two-colour se lection criterion to find galaxies lying at redshifts between 1.4 and 2.5. We investigate the redshift distribution of these BzKs using spectroscopic redshifts as well as a new photometric redshift catalogue and find respectively, 13% and 14% contamination from low redshift interlopers. We then com pare the relationship between star formation rate and stellar mass with three different star formation rate estimators, derived from the rest-frame ultra violet, mid-infrared and radio properties. We obtain similar relationships from each of these methods and discuss the inherent uncertainty in estimat ing high redshift star formation rates. Finally, we test the BzK selection method with two extreme z~2 galaxy populations. The BzK criterion is able to select submillimetre galaxies at redshifts from 1.4 to 2.5 even though they have extreme star formation rates, and it can also effectively select highly dust obscured galaxies.

Tato dizertační práce je zaměřena vývoj a ověřování nových postupů přispívajících ke zvýšení účinnosti bifaciálních solárních článků založených na monokrystalickém křemíku n-typové vodivosti. Tato práce přináší nové poznatky o vylepšených výrobních procesech a postupech použitých během výroby článků v ISC Konstanz. V rámci práce byly vyrobeny solární články typu n-PERT (Passivated Emitter Rear Totally diffused) s vysokou účinností, a to pomocí standartních procesů a zařízení používaných běžně při průmyslové výrobě. Zapojení těchto průmyslových postupů a metod umožnilo ověřit možnosti výroby n-typových článků za použití téměř totožného vybavení, jaké je potřeba pro výrobu p-typových článků. Zvýšení účinnosti bylo založeno především na vylepšení jednotlivých procesních kroků. Experimenty popsané v této práci dosvědčují zlepšení procesu difúze bóru, přizpůsobení parametrů pasivační a antireflexní vrstvy nově navrženému emitoru, zlepšení procesu metalizace ve smyslu využití past neobsahujících hliník, testování tisku rozličných motivů spolu s různými sekvencemi výpalu. V rámci práce byla testována možnost zamezení jevu potenciální indukované degradace (Potential Induced Degradation – PID) pomocí vhodného složení ARC a pasivační vrstvy. Vyrobené n-typové solární články dosáhly maximální hodnoty účinnosti 20,9 %.

Neste trabalho é apresentado um modelo algébrico para o cálculo de energias de ligação de núcleos pesados com N = Z baseado nas versões invariantes por isospin do Modelo de Bósons interatuantes (IBM). Com a utilização de uma interação adequada para a descrição dos modos isoescalar e isovetorial do emparelhamento nuclear adicionada àquelas interações que descrevem globalmente uma dada região de massa, foram ajustados os parâmetros da hamiltoniana e calculados núcleos com N = Z ao longo das camadas sd e pf. Deste modo, pôde-se fazer algumas predições, para suas massas do estado fundamental e para estados excitados, que oferecem um desafio às novas gerações de feixes radiativos que estão por vir.<br>In this work we present an algebraic model for calculating the binding energies of heavy nuclei with the same number of protons and neutrons which is based in the isospin invariant versions of the Interacting Boson Model (IBM). With an adequate interaction for the description of the isoscalar and isovector pairing modes of the residual nuclear interaction added to those terms responsible for the bulk properties of a given mass region, we have fitted the parameters of our algebraic Hamiltonian and have calculated nuclei with N=Z along the sd and pf shells. Therefore we were able to make some predictions, for their ground state masses as well as for the excited states, which offer a challenge to the new generations of radioactive nuclear beams.

Submitted by Tassia Roberta Zangiacomo null (tassia_zangiacomo@hotmail.com) on 2017-03-23T22:04:31Z No. of bitstreams: 1 TASSIA ROBERTA ZANGIACOMO - MESTRADO.pdf: 1004175 bytes, checksum: 12925ba240f8d9a89e295b32b2efb13e (MD5)<br>Approved for entry into archive by Luiz Galeffi (luizgaleffi@gmail.com) on 2017-03-24T17:23:14Z (GMT) No. of bitstreams: 1 zangiacomo_tr_me_rcla.pdf: 1004175 bytes, checksum: 12925ba240f8d9a89e295b32b2efb13e (MD5)<br>Made available in DSpace on 2017-03-24T17:23:15Z (GMT). No. of bitstreams: 1 zangiacomo_tr_me_rcla.pdf: 1004175 bytes, checksum: 12925ba240f8d9a89e295b32b2efb13e (MD5) Previous issue date: 2017-02-20<br>Este trabalho tem como objetivo construir os sistemas numéricos usuais, a saber, o conjunto dos números naturais N, o conjunto dos números inteiros Z, o conjunto dos números racionais Q e o conjunto dos números reais R. Iniciamos o trabalho tratando de noções sobre conjuntos e relações binárias. Em seguida, apresentamos o conjunto dos números naturais, definido através dos axiomas de Peano; o conjunto dos números inteiros via uma relação de equivalência com o conjunto dos números naturais; o conjunto dos números racionais, que são obtidos também via relação de equivalência, mas dessa vez com o conjunto dos números inteiros; a construção do conjunto dos números reais, feita via cortes no conjunto dos números racionais; e, para todos esses casos, mostramos a imersão do conjunto anterior no conjunto que surge na sequência. Por fim, observamos alguns materiais do ensino fundamental e médio com o intuito de investigar de que forma esses temas estão sendo apresentados para os alunos.<br>This work aims to construct the usual numerical systems, namely the set of natural numbers N, the set of integers Z, the set of rational numbers Q and the set of real numbers R. We begin the work dealing with notions about sets and binary relations. Next, we present the set of natural numbers, defined by Peano's axioms; the set of integers via an equivalence relation with the set of natural numbers; the set of rational numbers, which are also obtained via equivalence relation, but this time with the set of integers; the construction of the set of real numbers, made through cuts in the set of rational numbers; end for all these cases we show the immersion of the previous set in the ensemble that appears in the sequence. Finally, we observed some materials in elementary school and high school in order to investigate how these themes are being presented to the students.

Orientador: Elíris Cristina Rizziolli<br>Banca: Helton Hideraldo Bíscaro<br>Banca: Suzinei Aparecida Siqueira Marconato<br>Resumo: Este trabalho tem como objetivo construir os sistemas numéricos usuais, a saber, o conjunto dos números naturais N, o conjunto dos números inteiros Z, o conjunto dos números racionais Q e o conjunto dos números reais R. Iniciamos o trabalho tratando de noções sobre conjuntos e relações binárias. Em seguida, apresentamos o conjunto dos números naturais, definido através dos axiomas de Peano; o conjunto dos números inteiros via uma relação de equivalência com o conjunto dos números naturais; o conjunto dos números racionais, que são obtidos também via relação de equivalência, mas dessa vez com o conjunto dos números inteiros; a construção do conjunto dos números reais, feita via cortes no conjunto dos números racionais; e, para todos esses casos, mostramos a imersão do conjunto anterior no conjunto que surge na sequência. Por fim, observamos alguns materiais do ensino fundamental e médio com o intuito de investigar de que forma esses temas estão sendo apresentados para os alunos<br>Abstract: This work aims to construct the usual numerical systems, namely the set of natural numbers N, the set of integers Z, the set of rational numbers Q and the set of real numbers R. We begin the work dealing with notions about sets and binary relations. Next, we present the set of natural numbers, defined by Peano's axioms; the set of integers via an equivalence relation with the set of natural numbers; the set of rational numbers, which are also obtained via equivalence relation, but this time with the set of integers; the construction of the set of real numbers, made through cuts in the set of rational numbers; end for all these cases we show the immersion of the previous set in the ensemble that appears in the sequence. Finally, we observed some materials in elementary school and high school in order to investigate how these themes are being presented to the students<br>Mestre

The exotic region of the nuclear chart around the doubly-magic 78Ni (Z = 28, N = 50) nucleus presents an excellent testing ground for our understanding of nuclear structure. The region around N = 50 plays an important role in the astrophysical rapid neutron- capture (r) process. The robustness of the N = 50 conventional magic number could affect current knowledge of nuclear abundances. Measurements of 2+ and 4+ states offer one of the first indications of shell structure and evolution. Measurements of low-lying states in 81,82,83,84Zn were performed. 82,84Zn are the first two even-even nuclei beyond 78Ni, thus are an important test for the strength of the doubly-magic 78Ni core. The Zn nuclei were measured in the first and second experimental campaigns of the SEASTAR (Shell Evolution and Search for Two-plus energies At the RIBF) project conducted at the RIBF, RIKEN, Japan. In-flight fragmentation-fission beams were produced using a 238U primary beam of 345 MeV/nucleon. The BigRIPS spectrometer was used to identify and select the secondary beams impinged onto a liquid hydrogen target. γ rays were detected using DALI2, an array of 186 NaI detectors surrounding the target. The MINOS system provided vertex reconstruction by tracking the outgoing protons in (p, 2p) proton knockout reactions. Reaction products were identified using the ZeroDegree spectrometer. The 2+ and 4+ states in 82Zn were measured, the 4+1 was observed for the first time in this work along with two additional states. The 2+ and 4+ in 84Zn were measured for the first time, extending the known Zn systematics to N = 54. Two new transitions were observed and assigned within 81Zn, while two tentative transitions were seen in 83Zn. Two state-of-the-art shell model calculations were performed: Ni78-II utilised an inert 78Ni core with a large valence space, while the MCSM calculation allowed core-breaking configurations with a limited neutron valence space. Comparisons of these calculations to the results and region systematics have revealed that the breaking of the 78Ni core provides a significant contribution to low-lying states in the direct vicinity of 78Ni. However, the inclusion of core-breaking configurations also needs to be met with an ample model space to accommodate near future measurements of nuclei in the region. Interactions need to be developed to enable such accommodations in current shell-model calculations.

La mesure des masses des noyaux tres riches en protons est un moyen d'etudier la cohesion nucleaire a la limite de la stabilite. En particulier, les noyaux n = z presentent des proprietes d'appariement singulieres, appelees effets de wigner. Ces effets peuvent etre mis en evidence par l'etude de l'interaction residuelle entre le dernier proton et le dernier neutron, directement accessible par les masses, et permet de tester la symetrie de spin-isospin su(4) dans les noyaux. Egalement dans la region n = z = 34 ; 40 les noyaux ont un interet particulier dans la modelisation du processus rp en astrophysique nucleaire. Une experience a ete realisee en utilisant le deuxieme cyclotron du ganil -css2- comme spectrometre de masse de haute resolution. Les noyaux exotiques sont produits par reaction de fusion-evaporation entre un faisceau de 5 8ni a 4. 3 mev/a et des cibles de 2 4mg et 1 2c. Ils sont injectes dans css2 simultanement a des noyaux de masses connues, servant de reference pour la mesure. Les ions sont separes en temps au cours de leur acceleration et leurs difference relative de masses se deduisent directement de leur difference relative de temps de vol. Leur detection se fait par un telescope interceptif situe sur une sonde radiale mobile placee a l'interieur du cyclotron. Des simulations ont ete realisees auparavant concernant chaque etape de la methode afin d'optimiser la production, l'injection simultanee des ions, leur separation et leur identification pour l'appliquer a cette gamme de masses. L'analyse de l'experience a conduit, avec 4 noyaux de reference, a la determination des masses des noyaux n = z : 8 0zr, 7 6sr, 6 8se et a la deuxieme mesure de celle du noyau 8 0y, avec une precision de l'ordre de 10 - 6. Ces mesures ont permis de tester la validite de la symetrie su(4) dans la couche fp et de montrer l'impact des nouvelles masses sur la modelisation du processus rp par la comparaison avec differents modeles de masse.

The nuclear shell model (SM) has been very successful in describing the properties and the structure of near-stable and stable isotopes near the magic nuclei. Today, the advent of powerful facilities capable of producing radioactive isotopes far from stability has enabled the test of the SM on very proton-rich or neutron-rich magic nuclei. 100/50Sn50 is a proton-rich doubly-magic nucleus, but is nearly unstable against proton emission. Key topics of nuclear structure in this region include the location of the proton dripline, the effect of proton-neutron interactions in N ~ Z nuclei, single-particle energies of orbitals above and below the N = Z = 50 shell gaps, and the properties of the superallowed Gamow-Teller decay of ¹⁰⁰Sn. A decay spectroscopy experiment was performed on ¹⁰⁰Sn and nuclei in its vicinity at the RIKEN Nishina Center in June 2013. The isotopes of interest were produced from fragmentation reactions of 124/54Xe on a 9/4Be target, and were separated and identified on an event-by-event basis. Decay spectroscopy was performed by implanting the radioactive isotopes in the Si detector array (WAS3ABi) and observing their subsequent decay radiations. β⁺ particles and protons were detected by WAS3ABi, and γ rays were detected by a Ge detector array (EURICA). Of the proton-rich isotopes produced in this experiment, over 20 isotopes as light as ⁸⁸Zr and as heavy as ¹⁰¹Sn were individually studied. New and improved measurements of isotope/isomer half-lives, β-decay endpoint energies, β-delayed proton emission branching ratios, and γ-ray transitions were analyzed. In general the new results were well reproduced by the SM, highlighting a relatively robust ¹⁰⁰Sn core. However, the level scheme of ¹⁰⁰Sn's β-decay daughter nucleus ¹⁰⁰In was not conclusively determined because of several missing observations which were expected from various SM predictions. Significantly higher β-decay and γ-ray statistics are required on several nuclei, including ¹⁰⁰Sn, to evaluate the limit of the current understanding of their structure.<br>Science, Faculty of<br>Physics and Astronomy, Department of<br>Graduate

The beta+-decay half-lives of the neutron-deficient, odd-odd, N = Z nuclei, 74Rb, 78Y, 82NB and 86Tc were measured following the fragmentation of a primary 92Mo beam at an energy of 60 MeV per nucleon at the GANIL laboratory, France. They were measured by correlating beta+-decays with the implantation of unambiguously identified fragments. The deduced log10 ft1/2-values are consistent with 0+&rarr; 0+, Fermi superallowed transitions, which together with the measured beta+-detection efficiencies suggest T = 1, 1pi- 0+ ground states for these odd-odd, N = Z nuclei. These data represent the heaviest N = Z systems for which Fermi superallowed decays have been established. The results suggest that these nuclei can be used to extend the mass range used to test the Conserved Vector Current hypothesis of the standard model. In addition, an experiment using the reaction 58Ni + 28Si at a beam energy of 200 MeV was performed at the Laboratorio Nationale di Legnaro, Italy, using the EUROBALL spectrometer together with a charged particle silicon detector ball and an array of liquid scintillator neutron detectors. The measured values of the energies of the evaporated, charged-particles and those of the gamma-ray multiplicity (deduced using the liquid scintillator detectors), are used to implement a novel technique for the channel selection of weakly populated evaporation channels.

In this dissertation we expand on the study of Τn-factorizations or generalized integer factorizations introduced by D.D. Anderson and A. Frazier and examined by S. Hamon. Fixing a non-negative integer n, a Τn-factorization of a nonzero nonunit integer a is a factorization of the form a = Λ.a1.a2...at where t ≥ 1, Λ= 1 or -1 and the nonunit nonzero integers a1,a2,...,at satisfy a1 ≡ a2 ≡ ... ≡ at mod n. The Τn-factorizations of the form a = a1,a2,...,at (that is, without a leading -1) are called reduced Τn-factorizations. While similarities exist between the Τn-factorizations and the reduced Τn-factorizations, the study of one type of factorization does not elucidate the other. This work serves to compare the Τn-factorizations of the integers with the reduced Τn-factorizations in Z and the Τn-factorizations in N. One of the main goals is to explore how the Fundamental Theorem of Arithmetic extends to these generalized factorizations. Results regarding the Τn-factorizations in Z have been discussed by S. Hamon. Using different methods based on group theory we explore similar results about the reduced Τn-factorizations in Z and the Τn-factorizations in N. In other words, we identify the few values of n for which every integer can be expressed as a product of the irreducible elements related to these factorizations and indicate when one can do so uniquely.

The aim of the study will be the determination of the kinetic profiles of the polymerization of propene, ethene and their mixtures with commercial Ziegler-Natta catalyst by application of two different experimental procedures. The prepared polymer material will be utilized for the SEC analysis and subsequent evaluation of the concentration of active sites. The determined molecular mass distribution curves will be further investigated by the application of the procedure, which deconvolute the overall profile on the basic Flory's distribution functions. Then the comprehensive study about character and behavior of various types of active centers in dependence on time and type of monomer will result from this investigation.

This thesis is aimed at the study of high angular momentum states in neutron deficient nuclei in the mass 60 region, with approximately equal numbers of protons and neutrons, (N~Z). The main motivations of this work are to provide an insight into the mechanisms for generation of high angular momentum states in a limited particle valence space above the N=Z=28 doubly magic core, and to investigate the role of the isospin quantum number in heavy N=Z nuclei. The decay scheme for the odd-odd N=Z nucleus 6231Ga has been deduced for the first time, and the decay schemes for 61Zn and 61Cu have been extended. The data came from two experiments, the first using the reaction 24Mg + 40Ca at a beam energy of 65 MeV, performed at the Argonne National Laboratory, Chicago, US, using the germanium gamma-ray detector array 'AYEBALL' in conjunction with the Argonne Fragment Mass Analyzer and a gas filled ionisation chamber. The second experiment using the reaction 28Si + 40Ca at a beam energy of 88 MeV was performed at the Niels Bohr Institute, Riso, Copenhagen, Denmark using the 'PEX' gamma-ray detector array with a charged particle detector ball and an array of liquid scintillator neutron detectors. The data analysis techniques and results of the experimental analysis are presented. Gamma-ray energy spectra for different nuclei are shown according to the mass, neutron number and proton number of the nucleus. The proposed decay schemes are justified by coincidence and DCO arguments, and are compared to shell model calculations using a restricted pf5/2 g9/2basis. In the case of 62Ga, these are then compared with the latest IBM-4 calculation, which explicitly includes T=0 and T=1 bosons. Suggestions are also made for future work to complement this data.

Dissertation (PhD)--University of Stellenbosch, 2006.<br>ENGLISH ABSTRACT: The partial double bond character of the carbon-nitrogen bond of the (S)C-NRR’ moiety results in unsymmetrical dialkyl-substituted N-alkyl-N-alkyl(aryl)-N’-acylthioureas, R”C(O)NHC(S)NRR’ (HL) displaying E,Z configurational isomerism in solution. The isomerism manifests itself by the duplication of resonances of the N-alkyl groups in the 1H and 13C NMR spectra. In one class of these ligands where R and R’ groups are non-equivalent alkyl groups the isomerism is easily observable at 298 K in chloroform. In the other class where R’ is still an alkyl group and R is a para-substituted phenyl group the isomerism is only observable at much lower temperatures due to a lower barrier to rotation around the (S)C-N(alkyl)(para-X-Ph) bond (X = O-CH3, H and NO2). The electron-withdrawing nature of the nitro group in N-methyl-N-(4-nitro-phenyl)-N’-2,2-dimethylpropanoylthiourea, HL3A and N-pentyl-N- (4-nitro-phenyl)-N’-2,2-dimethylpropanoylthiourea, HL3D result in the E,Z isomerism of these ligands not observable even at 198 K in dichloromethane. The distribution of E and Z isomers of the unbound ligands vary depending on these R and R’ groups. Several E isomers of these ligands have been isolated and structurally characterised and the (S)C-NRR’ bond falls in the range [1.343(3) – 1.329(3) Å] which shorter than the average C-N single bond of 1.472(5) Å. The E,Z configurational isomerism in the unbound ligands is passed on to the Pt(II) chelates derived from these ligands. The presence of cis-[Pt(ZZ-L-S,O)2], cis-[Pt(EZ-L-S,O)2] and cis-[Pt(EE-L-S,O)2] is readily observable by means of 195Pt NMR spectroscopy which shows three well resolved resonances, and this can be confirmed by 1H and 13C NMR spectra of these complexes. The 195Pt nuclei are spatially linked to the 13C nuclei, four bonds away resulting in 4J(195Pt-13C) couplings with N-CH2- or N-CH3 carbons in a W pathway. The 195Pt NMR spectra are also linked to N-CH2- or N-CH3 proton resonances by means of the ZZ, EZ and EE isomer distributions. Assignment of these configurational isomers was then achieved by means of a combination of low magnetic field 13C NMR spectra and high-resolution gHSQC (1H/13C) NMR experiments. 1H NMR rotational dynamics study showed that the barrier to rotation, ΔG≠, around the (S)C-N(Me)(para-X-Ph) bond in cis-bis(N-methyl-N-(4-methoxy-phenyl)-N’-2,2-dimethylpropanoylthioureato)platinum(II), cis-[Pt(L1AS, O)2]; cis-bis(N-methyl-N-phenyl-N’-2,2-dimethylpropanoylthioureato)platinum(II), cis-[Pt(L2A-S,O)2] and cisbis( N-methyl-N-(4-nitro-phenyl)-N’-2,2-dimethylpropanoylthioureato)platinum(II), cis-[Pt(L3A-S,O)2] complexes was observed to follow the order: (electron-withdrawing group) NO2 < H < (electron-donating group) O-CH3. The ZZ isomer was observed to be favoured over the EZ and EE isomers in this order of the para-substituent on the Nphenyl group. The 1H dynamic NMR trends about the barrier to rotation, ΔG≠, around the (S)C-N(Me)(para-X-Ph) bond were also complemented by DFT linear transit calculations. The isomer distributions were also influenced by solvent polarity and the temperature at which the distributions are determined apart from the electronic influence of the para-substituent of the N-phenyl group. The ZZ, EZ and EE isomers of complexes derived from N-alkyl-N-(para-X-Ph)-N’-acylthioureas with varying Nalkyl substituent (methyl, isopropyl, cyclohexyl and n-pentyl) were determined from the 195Pt NMR spectra which were measured under identical conditions. The ZZ isomer was observed to be favoured over the EZ and EE isomers upon methyl group substitution with a bulkier alkyl group in the order: methyl < isopropyl < cyclohexyl < n-pentyl. Qualitatively it has been shown that a bulkier N-pentyl group increases the barrier to rotation around the (S)CN( alkyl)(para-X-Ph) bond over the N-methyl group and this leads to higher concentrations of the ZZ isomer over the EZ and EE isomers. The combined effects of the electron-donating substituent (X = O-CH3) on the N-(para-X-Ph) group and the bulkier N-alkyl group (n-pentyl) result in highest ZZ concentration (76 %) over EZ and EE isomers in the complex cis-bis(N-pentyl-N-(4-methoxy-phenyl)-N’-2,2-dimethylpropanoylthioureato)platinum(II), cis-[Pt(L1DS, O)2]. The lowest concentration ZZ (27 %) is obtained in the complex cis-bis(N-methyl-N-(4-nitro-phenyl)-N’-2,2- dimethylpropanoylthioureato)platinum(II), cis-[Pt(L3A-S,O)2] when the coordinated ligand has both N-methyl group and N-(4-nitro-Ph) group which both lower the barrier to rotation around the (S)C-N(alkyl)(para-X-Ph) bond. A crystal of the complex cis-bis(N-pentyl-N-(4-methoxy-phenyl)-N’-2,2-dimethylpropanoylthioureato)platinum(II), cis-[Pt(L1D-S,O)2] has been isolated and structurally characterised and was shown to be in the ZZ configuration, which is the major component (76 %) in chloroform. This is the first example of Pt(II) chelates with asymmetrically disubstituted ligands to be reported.<br>AFRIKAANSE OPSOMMING: Die gedeeltelike dubbelbinding karakter van die koolstof-stikstof-binding van die (S)C-NRR’-moieteit lei tot onsimmetriese dialkiel-gesubstitueerde N,N-dialkiel-N’-asieltioureums, R”C(O)NHC(S)NRR’ (HL) wat E,Zkonfigurasionele isomerie in oplossing besit. Die isomerie is sigbaar in die verdubbelling van die seine van die Nalkielgroepe in die 1H- en 13C-KMR spektra. In een so klas ligande waar R- en R’-groepe nie-ekwivalente alkielgroepe is, is isomerie duidelik sigbaar by 298 K in chloroform. In die ander klas waar R’ steeds ’n alkielgroep is, en R ’n para-gesubstitueerde feniel groep, is die isomerie alleenlik sigbaar by baie laer temperature as gevolg van ’n laer rotasieversperring om die (S)C-N(alkiel)(para-X-Ph)-binding (X = O-CH3, H and NO2). Die elektrononttrekkende aard van die nitrogroep in N-metiel-N-(4-nitrofeniel)-N’-(2,2-dimetielpropanoïel)tioüreum, HL3A en N-(4-nitrofenyl)-N-pentiel-N’-(2,2-dimetielpropanoïel)tioüreum, HL3D lei daartoe dat die E,Z-isomerie van die ligande nie eers by 198 K in dichlorometaan waargeneem word nie. Die verspreiding van die E en Z isomere verskil na gelang van die R en R’ groepe. Verskeie E-isomere van hierdie ligande is geïsoleer en struktureel gekarakteriseer en die (S)C-NRR’-bindingslengte is in ‘n gebied [1.343(3) – 1.329(3) Å] wat korter is as die gemiddelde C-N-enkelbindingslengte van 1.472(5) Å. Die Pt(II) chelate wat afgelei is van die ligande is blootgestel aan die E,Z-konfigurasie isomere van die ongebinde ligande. Die teenwoordigheid van cis-[Pt(ZZ-L-S,O)2], cis-[Pt(EZ-L-S,O)2] en cis-[Pt(EE-L-S,O)2] is maklik waarneembaar deur middel van 195Pt-KMR-spektroskopy wat drie goed geresolueerde seine toon, en dit kan bevestig word met 1H- en 13C-KMR spectra van hierdie komplekse. Die 195Pt kerne is ruimtelik geskakel met die 13C kerne deur vier bindings wat aanleiding gee tot 4J(195Pt-13C)-koppelings met N-CH2- of N-CH3-koolstofatome in ‘n Wkonformasie. Die 195Pt KMR spektra word geskakel met die N-CH2- of N-CH3-protonresonansies in al drie die moontlike ZZ, EZ en EE kompleksisomere. Toekenning van die konfigurasionele isomere is dan bewerkstellig deur middel van ‘n kombinasie van lae magneetveld 13C-KMR spectra en hoë resolusie gHSQC (1H/13C) KMR experimente. 1H-KMR-rotasiedinamiek studie toon dat die rotasiegrens, ΔG≠, om die (S)C-N(Me)(para-X-Ph)-binding in cisbis( N-metiel-N-(4-metoksifeniel)-N’-2,2-dimetielpropanoïeltioureato)platinum(II), cis-[Pt(L1A-S,O)2]; cis-bis(Nfeniel- N-metiel-N’-2,2-dimetielpropanoïeltioureato)platinum(II), cis-[Pt(L2A-S,O)2] en cis-bis(N-metiel-N-(4- nitrofeniel)-N’-2,2-dimetielpropanoïeltioureato)platinum(II), cis-[Pt(L3A-S,O)2] komplekse was met die volgende orde bepaal: (elektron-ontrekkende groep) NO2 < H < (elektron-skenkende groep) O-CH3. Die ZZ-isomeer blyk by voorkeur te vorm bo die EZ- en EE-isomere in dieselfde orde as hierbo wat betref para-substituent aan die Nfenielgroep. Die 1H dinamiese KMR tendencies ten opsigte van die rotasiegrens, ΔG≠, om die (S)C-N(Me)(para-XPh)- binding is gekomplimenteer met DFT-linêre organgs berekeninge. Die isomer verspreidings blyk ook beïnvloed te word deur die oplosmiddel polariteit en die temperatuur waarby die verspreidings bepaal is, buiten die elektroniese invloed van die para-substituent aan die N-fenielgroep. Die ZZ, EZ en EE isomeer verspreiding van komplekse wat afgelei is van N-alkiel-N-(para-X-Ph)-N’-asieltioureums met veranderlike N-alkiel substituente (metiel, isopropyl, sikloheksiel, en n-pentiel) is vasgestel deur middel van die 195Pt KMR wat opgeneem is onder identiese kondisies. Die ZZ-isomeer blyk die verkose isomeer te wees bo die EZen EE-isomere waar die metiel substituent vervang word met ‘n groter alkiel groep in die orde van: metiel < isopropiel < sikloheksiel < n-pentiel. Dit is kwalitatief getoon dat die groter N-pentielgroep die rotasiegrens verhoog vir rotasie om die (S)C-N(alkiel)(para-X-Ph)-binding bo dié van die N-metielgroep wat aanleiding gee tot hoër konsentrasies van die ZZ-isomeer relatief tot die EZ- en EE-isomere. Die gekombineerde uitwerking van die electron-skenkende substituent (O-CH3) op die N-(para-X-Ph)-groep en die groter N-alkiel groep (n-pentiel) gee aanleiding tot die hoogste ZZ-konsentrasie (76%) bo EZ- en EE-isomere in die kompleks cis-bis(N-pentiel-N-(4- metoksifeniel)-N’-2,2-dimetielpropanoïeltioureato)platinum(II), cis-[Pt(L1D-S,O)2]. Die laagste konsentrasie ZZ (27%) is verkry in die kompleks cis-bis(N-metiel-N-(4-nitrofeniel)-N’-2,2-dimetielpropanoïel)tioureato)platinum(II), cis-[Pt(L3A-S,O)2] waar die gekoördineerde ligand beide die N-metiel- sowel as die N-(4-nitro-Ph)-groep, wat albei die rotasiegrens van die (S)C-N(alkiel)(para-X-Ph)-binding verlaag. ‘n Kristalstruktuur van die kompleks cis-bis(N-pentiel-N-(4-metoksifeniel)-N’-2,2-dimetielpropanoïeltioureato) platinum(II), cis-[Pt(L1D-S,O)2] wat geïsoleer is, is struktureel gekarakteriseer en is in die ZZ-konfigurasie, wat die hoofkomponent (76%) is in chloroform. Hierdie is die eerste voorbeeld van Pt(II) chelate met asimmetriese digesubstitueerde ligande om geraporteer te word.

1) Utilisation des corpus oraux en FLE. On postule une unité minimale d'information syntaxique qui opère dans les situations d'interaction communicative. Au niveau macro-syntaxique, cette unité informe la syllabe proéminente. Des positions linéarisées sont décrites pour comparer les syllabations concurrentes. Sur cette base, le gabarit syllabique opératif dans l'interlangue de l'apprenant peut être modifié par la présentation d'un modèle alternatif. Les productions déviantes constatées dans les corpus (intra-langue) justifient l'intervention d'un didacticien-tuteur et la formulation de règles établissant des rapports phonologiques entre la syllabation erratique et une syllabation modèle. 2) Les ressources. Les enregistrements de corpus oraux suivant le protocole PFC (Durand, Laks & Lyche, 2002/2009), permettent de répertorier les contextes de liaison de 14 informateurs de niveau B1/B2 apprenants de FLE à Madrid. En lecture les liaisons sont classées selon les analyses disponibles du texte PFC conçu pour étudier la variation chez des francophones. Les transcriptions orthographiques des conversations ont été réalisées par un transcripteur du sous projet IPFC (Detey, et al. 2010) qui vise l'alignement et le traitement de corpus oraux de locuteurs non francophones. 3) Traitement de données et perspectives. Trois notations (lecture, conversation, prosodie) marquent les productions pour analyse. Leur élaboration s'inspire de la méthodologie appliquée en acquisition du français L1 (Chevrot, Dugua & Fayol, 2008) et repèrent les consonnes parasites, omissions et erreurs à distance. Des critères prosodiques sont proposés pour reconstruire la syntaxe par l'élaboration d'exercices correctifs.

This thesis details the study of N~Z~28 nuclei obtained using the fusion evaporation reactions 19Ne +40Ca at a beam energy of 70 MeV and 24Mg-40Ca at a beam energy of 65 MeV. The 19Ne data constitute the first tests of a neutron-deficient Radioactive Ion Beam (RIB) for high-spin nuclear spectroscopy. The radioactive Ne beam was supplied by the coupled cyclotrons at the Louvain-la-Neuve facility, Belgium. Emitted gamma-rays were detected by an array of 7 TESSA-style Ge-detectors in the backward hemisphere in two rings. A degree of channel selection was also allowed by identifying evaporated charged particles with an array of 128 silicon-strip detectors (LEDA array). Background subtraction of radiation from the decay of the beam was achieved using the timing properties of the pulsed beam and through particle detection using the LEDA charged particle array Information on the relative evaporation residue cross-sections was obtained and the problems associated with performing such experiments in a high radioactive background environment are addressed. New information on the high spin states of 58Ni was obtained using the reaction 40Ca (24Mg, alpha2p), performed at the ATLAS facility at Argonne National Laboratory. Emitted 7-rays were detected by high efficiency AYEBALL array which consisted of 18 EUROGAM and TESSA-style Compton suppressed Ge-detectors in four annular rings. Channel selection is demonstrated by use of (a) mass selection using the Argonne Fragment Mass Analyser (FMA), (b) a split anode ionization chamber at the back of the FMA, and (c) an array of 11 neutron detectors in a ring at forward angles. The effectiveness of using recoil-gated gamma coincidence data for the study of nuclear structure in neutron-deficient nuclei close to the proton drip-line is shown. The excited states of 58Ni are compared with OXBASH shell model calculations and the problems associated with forming high angular momentum states in the limited valence space are addressed.

Nous présentons un corpus de lectures et de conversations d'apprenants de FLE élaboré sous le protocole PFC (Durand, Laks &amp; Lyche, 2002). Les lectures révèlent des problèmes phono-tactiques et la non reconnaissance des consonnes de liaison. Dans les conversations on peut constater que les groupes accentuels sont décalés par rapport aux morphèmes intonatifs attendus pour un locuteur de français standard ; l'accent démarcatif n'est pas reconnu et l'information phonologique reste déficiente. L'hypothèse est que le gabarit syllabique de l'interlangue produit des interférences qui empêchent la constitution de l'énoncé français. Nous constatons par ailleurs que la syllabation atypique concerne les mêmes positions en conversation qu'en lecture : /n/, /z/ et /t/. On conclut qu’il s'agit de positions prosodiques opaques dont l'identification peut aider l'apprenant à reconstruire l'énoncé en l'ajustant à la syntaxe du français. Nous postulons alors une structure syntaxique minimale où est représentée la consonne épenthétique définie par /ʔ/ (Encrevé, 1988); elle permet de rendre explicites des critères métriques par lesquels éviter la production de segments parasites. Nous proposons finalement une approche didactique basée sur la phonologie dont nous avons présenté quelques exemples d'exercices comme modèle. Ceux-ci permettent la reconnaissance des consonnes de liaison et favorisent la production de syntagmes conformes<br>1) Using speech corpora in FFL. We postulate a minimal syntactical informed unit in communicative interaction. On macro—syntactical level, this syntactical unit informs prominent syllables. Linear positions are then described in order to compare syllabification competitors. Operative syllabic template in learner’s interlanguage can then be modified by presentation of an alternative model. Deviant productions identified in corpora (intra—language) justify action—oriented learning by tutors and elaboration of rules to describe phonological relations between erratic syllabification and other syllabification models. 2) Resources. Corpora have been recorded according to the PFC protocol (Durand, Laks &amp; lyche, 2002/2009). Inventory of &lt;&lt; Liaison » contexts for reading and conversation have been compiled on l4 informants [level Bl/B2) tested in Madrid. In reading, liaisons have been classified according to the available PFC reading analyses over French speakers studies in linguistic variation. Conversational orthographic transcriptions were conducted by a transcriber of IFFC (Detey,et al. , 2010). This subproject deals with alignment, treatment and study of non-French speakers oral corpora. 3) Data processing and perspectives. Three notations (reading, conversation, prosody) classify productions to be analyzed. They are inspired in corpora L1 acquisition processing (Chevrot, Dugua &amp; Fayol, 2008) where parasite consonants’, omissions and mistakes “in distance” are concerned. Prosodic criteria are put forward to rebuild syntax structures and to elaborate corrective exercices

Several low-lying levels in the exotic N = Z nucleus 62Ga have been observed for the first time using a new fast β-decay tagging system at the Argonne National Laboratory. The system provides enhanced selectivity on proton-rich nuclei, produced in heavy-ion fusion-evaporation reactions, that exhibit ‘fast’ β decays compared with isobaric contaminants. A 103 MeV beam of 40Ca ions, produced by the Argonne Tandem-Linac Accelerator System (ATLAS), was used to bombard an isotopically enriched 24Mg target, allowing 62Ga nuclei to be produced via the evaporation of one proton and one neutron in heavy-ion fusion evaporation reactions. Prompt γ rays were detected by the Gammasphere array, and recoiling reaction products dispersed by their mass-to-charge ratio by the fragment mass analyzer (FMA). New β-tagging capabilities were provided by the installation of a 1 mm thick, highly segmented 160×160 double-sided Silicon strip detector (DSSD) at the focal plane of the FMA, which allowed implanted reaction residues to be correlated in both space and time with subsequent β+ decays. The experiment was carried out with the benefit of digital acquisition systems for the Gammasphere, FMA and DSSD. The exotic nucleus 62Ga has a β-decay half-life of ∼ 100 ms. The main contaminants in the 40Ca + 24Mg fusion-evaporation reaction are 62Zn, which has a ∼ 9 hour half-life, and 58Ni, which is stable. A clean ‘singles’ γ-ray spectrum of 62Ga transitions was made permissible for the first time by the high levels of selectivity achieved, through requiring the detection of a β particle in the DSSD in close proximity to implanted reaction residues within 400 ms of implantation. Several low-lying low-spin states are reported in this thesis work, and discussed in the context of previous experimental results and theoretical predictions made using shell model, deformed shell model and IBM-4 calculations.

La mesure des masses des noyaux permet d'obtenir l'énergie de liaison qui reflète toutes les interactions régnant au sein du noyau atomique. Pour les noyaux N=Z, l'énergie de liaison présente une singularité qui peut être reproduite par l'ajout d'un terme de Wigner dans les formules de masses. Cet effet est étudié par l'intermédiaire de l'interaction neutron-proton qui présente un excédent pour les noyaux N=Z qui tend à disparaître pour les noyaux pair-pair lorsque le nombre de masse A augmente. Cependant, pour les noyaux N=Z impair-impair, l'interaction neutron-proton tend à se stabiliser au delà de A=40 avec un excédent d'environ 2 MeV. Une mesure de la masse atomique du noyau N=Z=37 74Rb a été réalisée avec le spectromètre à radiofréquence MISTRAL qui est installé au CERN. La fréquence cyclotron du 74Rb à l'intérieur d'un champ magnétique est mesurée en la synchronisant avec la fréquence d'un champ électrique, qui module l'énergie cinétique des ions. Cette fréquence cyclotron est comparée à celle d'un noyau de référence, de masse bien connue, à l'intérieur du même champ magnétique et le rapport des deux fréquences donne le rapport des deux masses atomiques. Cette mesure dont la précision obtenue est de 116 keV, a confirmé la stabilisation de l'interaction neutron-proton pour les noyaux N=Z impair-impair. Différentes formules de masses ont été étudiées et l'interaction neutronproton a été calculée à partir des masses prédites par ces formules puis comparée aux valeurs expérimentales. En particulier, le modèle IBM-4, basé sur la symétrie SU(4) a été utilisé pour calculer les masses des noyaux N=Z et des noyaux pair-pair et ainsi en déduire l'interaction neutron-proton pour les noyaux N=Z pair-pair. Un autre point intéressant du 74Rb est sa décroissance super-permise vers le 74Kr dont l'énergie et la demi-vie permettent de calculer la constante de couplage vecteur de la théorie électrofaible, qui est supposée indépendante du noyau par l'hypothèse CVC.

When target and projectile nuclei have a difference in neutron to proton ratio (N/Z), the quasiprojectiles formed in a deep inelastic collision (DIC) should have a mean N/Z between the N/Z of the target and the N/Z of the projectile, depending on the amount of N/Z equilibration that occurred. Data from six reaction systems at two beam energies (32 and 45 MeV/nucleon) were collected. The systems in order of increasing difference between target and projectile N/Z (shown in parentheses) are 40Ar + 112Sn (∆N/Z = 0.018), 48Ca + 124Sn (∆N/Z = 0.080), 48Ca + 112Sn (∆N/Z = 0.160), 40Ca + 112Sn (∆N/Z = 0.240), 40Ar + 124Sn (∆N/Z = 0.258) and 40Ca + 124Sn (∆N/Z = 0.480). The quasiprojectile N/Z was determined by two techniques. The first technique used the isotopically resolved fragments to reconstruct the quasiprojectile N/Z. The second technique, developed in this thesis, used fragment yield ratios and a simple equation to simultaneously fit all six systems to determine the quasiprojectile N/Z. Simulations and a filter of the FAUST (Forward Array Using Silicon Technology) acceptance were used to calculate neutron loss; this accounted for the difference between the two techniques. To study the fragmentation of quasiprojectiles the fragment yields were used to calculate the isobaric, isotopic, fractional and mean N/Z yields. The results showed that as neutron richness increased, more neutron-rich fragments were produced. In addition observation showed evidence for an inhomogeneous distribution of N/Z between the light charged particles (LCPs Z less than 3) and intermediate mass fragments (IMFs Z greater than 2). The theoretical results, which used different values of the symmetry energy, were compared to experimental data to determine which symmetry energy best represents the experimental data. The comparison showed the experimental data was the overall best fit with a lower value of the symmetry energy. These results were not conclusive and further investigation is required.

La these porte sur l'etude du diagramme de phase d'equilibre des modeles de spins bidimensionnels a symetrie z(5), et du diagramme de phase dynamique des modeles clock z(n). Pour la determination des proprietes critiques de z(5), on utilise dans le formalisme hamiltonien issu de la matrice de transfert, deux methodes complementaires appliquees a l'etude du mass-gap: les series a haute temperature et le calcul exact des chaines finies. Par des simulations numeriques, nous traitons la ligne des transitions faiblement du premier ordre des modeles z(5) et le diagramme de phase dynamique des modeles clock

The second order rate constants for nucleophilic substitution by methoxide of (Z)- and (E)-O-methylbenzohydroximoyl fluorides [C6H4C(F)=NOCH3] with various substituents on the phenyl ring [p-OCH3 (1h, 2h), p-CH3 (1g, 2g), p-Cl (1f, 2f), p-H (1e, 2e), (3,5)-bis-CF3 (1i, 2i)] in 90:10 DMSO:MeOH have been measured. A Hammett plot of these rate constants vs σ values gave positive ρ values of 2.95 (Z isomer) and 3.29 (E isomer). Comparison of these rates with methoxide substitution rates for Omethylbenzohydroximoyl bromide [C6H4C(Br)=NOCH3] and Omethylbenzohydroximoyl chloride [C6H4C(Cl)=NOCH3] reveal an element effect for the Z isomers of Br:Cl:F(1e) = 2.21:1.00:79.7 and for the E isomers of Cl:F(2e) = 1.00:18.3. With the p-OCH3-imidoyl halides the following element effects are found: Br:Cl:F(1h) = 2.78:1.00:73.1 for the Z isomer and Br:Cl:F(2h) = 1.97:1.00:12.1 for the E isomer. Measurement of activation parameters revealed ∆S≠ = -17 eu for 1e and ∆S≠ = -9.9 eu for 2e. Ab initio calculations (HF/6-31+G*, MP2/6-31+G*//HF/6-31+G*, B3LYP/6- 31+G*//HF/6-31+G*, HF-SCIPCM/6-31+G*//HF/6-31+G*) were performed to define the reaction surface. These calculations demonstrate a relatively large barrier for nucleophilic attack in relation to halogen loss and support the experimental findings that this reaction proceeds by an addition-elimination mechanism (AN# + DN). The imidoyl fluorides have been used to synthesize highly functionalized O-methyloximes by reaction with enolate anions derived from malononitrile, ethyl cyanoacetate, and diethyl malonate. Acid-catalyzed isomerization of compounds containing the O-methyloxime moiety have been investigated with ab initio calculations (HF/6-31+G*, MP2/6- 31+G*//HF/6-31+G*, B3LYP/6-31+G*//HF/6-31+G*). Barriers for rotation around the C-N bond following protonation have been calculated. The calculated barriers are discussed in relation to an isomerization mechanism of protonation-rotation versus a nucleophilic catalysis.

Oleaginous yeasts posses the ability to accumulate increased amount of lipids under appropriate conditions. These microbial lipids vary in the composition of fatty acids which results in their wide application in the biotechnological industry. This master thesis focuses on the lipid production and fatty acids composition from waste substrates by the yeasts Metschnikowia depending on various cultivation conditions. The influence of temperature, the ratio of carbon and nitrogen in medium, and the concentration of different carbon sources was studied. The cheap and easy available waste substrates as glycerol and animal fat were used for the cultivation. The production characteristics of the yeasts were monitored by various technique including gas chromatography, Raman spectroscopy and fluorescence microscopy FLIM. Moreover, the partial optimalization of the pulse field gel electrophoresis was applied in order to characterize the karyotype of the yeasts Metschnikowia. All the studied strains were able to use the waste substrates and at the same time to produce lipids. The amount of lipids and mainly their compositions vary depending on the yeast strain and on the culture conditions. Nevertheless, the ability of the yeasts to produce significant amount of unsaturated fatty acids by manipulation of culture conditions was proved. The maximum lipid yield was achieved by M. pulcherrima 149 on glycerol medium and by M. andauensis 129 on medium containing waste animal fat.

Le noyau est généralement décrit comme un ensemble de protons et de neutrons liés dans un potentiel de champ moyen. Cependant afin d'obtenir une meilleure description, il convient de tenir compte des interactions locales dont principalement l'appariement. Les appariements neutron-neutron et proton-proton sont assez bien étudiés alors que ce n'est pas le cas de l'appariement neutron-proton. Celui-ci peut être soit isovectoriel similaire à l'appariement nn/pp, soit isoscalaire et donc dans ce cas vraiment méconnu. La surliaison des noyaux N=Z pourrait être une manifestation de l'appariement np.Nous avons effectué l'étude de l'appariement np par réactions de transfert de paires np. Dans ce cas il est attendu que la section efficace de transfert de paires np soit augmentée en présence d'un appariement np important. L'appariement np devrait être important dans les noyaux N=Z avec des orbitales de J élevé. Or, des faisceaux de ces noyaux ne sont accessibles que depuis le développement des installations de faisceaux radioactifs.Nous avons effectué notre expérience au GANIL (Caen) avec un montage permettant une détection des produits issus de la réaction de transfert (p, ³ He). Cette réaction met en jeu à la fois des paires np isovectorielles et isoscalaires. Nous avons utilisé des faisceaux de ⁵⁶ Ni et de ⁵²Fe permettant d'observer l'évolution de l'appariement np avec l'occupation de la couche 0f7/2.Tout d'abord, nous avons analysé les données issues de la réaction ⁵⁶Ni(p,d)⁵⁵Ni et extrait des résultats que nous avons comparé à ceux existants. Cette démarche a permis de valider la procédure d'analyse des données.Après analyse des données issues de la réaction ⁵⁶Ni(p,3He)⁵⁴Co, nous avons extrait les populations des états du ⁵⁴Co qui donnent des informations sur l'intensité relative des deux types d'appariement np pour le noyau ⁵⁶Ni et montrent que l'appariement np isovectoriel est dominant dans ce noyau.De plus, dans le cadre d'un développement d'un futur détecteur de particules chargées, un travail de R&amp;D sur la discrimination des particules légères par la forme des signaux a été réalisé et est présenté<br>A nucleus is described as a set of independent neutrons and protons linked by a mean-field potential. However, in order to have a better description one needs to take in account some residual interactions such as pairing. Neutron-neutron and proton-proton pairings are well-studied but neutron-proton pairing is not well-known. np pairing can be isovector pairing such as nn and pp pairing or isoscalar which is yet unknown. Overbinding of N=Z nuclei could be a manifestation of np pairing.We have studied np pairing through transfer reactions. In this case, the cross-section of np pair transfer is expected to be enhanced in the presence of important np pairing. np pairing is expected to be important in N=Z nuclei with high J orbitals. Since the development of radioactive beam facilities, such beams are only available.The experiment was performed at GANIL with an efficient set-up so as to detect products from the (p,³He) transfer reaction. This reaction is affected by isovector and isoscalar np pairing. We used ⁵⁶Ni and ⁵²Fe beams so as to see the effect of the occupancy of 0f7/2 shell on the np pairing.First, we analysed the data from the ⁵⁶Ni(p,d)⁵⁵Ni reaction and we compared the results with the literature to validate analysis procedure.After analysing data from the ⁵⁶Ni(p,3He)⁵⁴Co reaction and extracting the population of the various states of ⁵⁴Co, we obtained information about the relative intensity between isoscalar and isovector np pairing in ⁵⁶Ni showing the predominance of isovector np pairing in this nucleus .Moreover, in the framework of developing a new charged particle detector, R&amp;D on the discrimination of light nuclei using pulse shape analysis was performed and is presented

An experiment was performed at the National Superconducting Cyclotron Laboratory at Michigan State University, USA. Transition strengths for gamma decays from low-lying excited states in A ~ 70 nuclei have been deduced from lifetime measurements using the recoil distance Doppler shift and gamma-ray lineshape methods in conjunction with nucleon knockout and inelastic scattering reactions. The results confirm the collectivity previously reported for the 2^+ -> 0^+ decay in 68Se and reveal a relative decrease in collectivity in 70Br. This trend is reproduced by shell model calculations using the GXPF1A interaction in the fp model space including the Coulomb, spin-orbit and isospin non-conserving interactions. The 3^+ -> 2^+ decay in 70Br is found to have a very small B(M1) value, which is consistent with the configuration of the state being dominated by the coupling of f5/2 and p1/2 nucleons. The results suggest the g9/2 orbit does not play an important role at low spin in these nuclei. The B(E2) values for the decays of the T = 1 2^+ states in 70Br and 70Se are almost identical, suggesting there is no major shape change between the two nuclei at low spin. New gamma rays have been identified in 68Se and 69Se. gamma-gamma coincidence measurements have allowed one of the two new gamma rays observed in 69Se to be placed in the level scheme. Shell model calculations with the GXPF1A interaction in the fp model space suggest that this new gamma ray comes from a previously unobserved excited 1/2^- state. Lifetimes of excited states in 72Kr, 66Ge, 69Se and 65Ga have also been extracted and, where possible, compared to previous work.

Tato disertační práce se zabývá odhadem pózy kamery z korespondencí 3D a 2D přímek, tedy tzv. perspektivním problémem n  přímek (angl. Perspective- n -Line, PnL). Pozornost je soustředěna na případy s velkým počtem čar, které mohou být efektivně řešeny metodami využívajícími lineární formulaci PnL. Dosud byly známy pouze metody pracující s korespondencemi 3D bodů a 2D přímek. Na základě tohoto pozorování byly navrženy dvě nové metody založené na algoritmu přímé lineární transformace (angl. Direct Linear Transformation, DLT): Metoda DLT-Plücker-Lines pracující s korespondencemi 3D a 2D přímek a metoda DLT-Combined-Lines pracující jak s korespondencemi 3D bodů a 2D přímek, tak s korespondencemi 3D přímek a 2D přímek. Ve druhém případě je redundantní 3D informace využita k redukci minimálního počtu požadovaných korespondencí přímek na 5 a ke zlepšení přesnosti metody. Navržené metody byly důkladně testovány za různých podmínek včetně simulovaných a reálných dat a porovnány s nejlepšími existujícími PnL metodami. Metoda DLT-Combined-Lines dosahuje výsledků lepších nebo srovnatelných s nejlepšími existujícími metodami a zároveň je značně rychlá. Tato disertační práce také zavádí jednotný rámec pro popis metod pro odhad pózy kamery založených na algoritmu DLT. Obě navržené metody jsou definovány v tomto rámci.

La spectroscopie d'electrons auger est utilisee pour etudier la double capture electronique intervenant lors des collisions a#z#+ + he (z = 610) a basse et tres basse energie de projectile. L'objectif est de rechercher l'influence de l'energie de collision sur les mecanismes responsables de la double capture. Les spectres d'electrons auger montrent deux comportements differents pour les sections efficaces de double capture. Les sections efficaces de production des configurations a electrons quasi equivalents 2l3l et 2l4l de c#4#+ et n#5#+, 3lnl (n = 35) de n#5#+, o#6#+ et ne#8#+ decroissent ou restent constantes lorsque l'energie de collision diminue. En revanche, les sections efficaces attribuees aux configurations a electrons non equivalents 2lnl (n 5) de c#4#+ et n#5#+, 3lnl (n 6) de n#5#+, o#6#+ et ne#8#+ restent constantes ou augmentent lorsque la vitesse du projectile diminue. Il ressort de ces experiences que les processus dielectroniques, dus a l'interaction electron-electron, sont responsables du peuplement des configurations a electrons non equivalents et deviennent de plus en plus importants quand l'energie decroit de 22 qkev a 0. 2 qkev. L'etude du systeme collisionnel n#7#+ + ne est egalement menee sur un large domaine d'energie (2170 kev). Le processus d'excitation dielectronique, mettant en jeu l'interaction entre deux electrons de la cible, est clairement mis en evidence et est a l'origine de la capture correlee d'un electron fortement lie 1s et d'un electron 2l de la cible. Le resultat essentiel est que dans tout le domaine d'energie explore, et meme aux plus basses energies de collision, les sections efficaces associees au processus d'excitation dielectronique restent significatives.

Les masses des noyaux loin de la stabilité présentent un intérêt particulier en physique nucléaire, et plusieurs méthodes, de précision variable, ont été développées pour entreprendre leur mesure. Une technique de mesure directe par temps de vol utilisant le spectromètre SPEG du GANIL a été étendue a la mesure des masses de noyaux riches en protons proches de la ligne N = Z dans la région de masses a 60-80, connue pour fournir des données pour la modélisation du processus astrophysique RP et des informations importantes sur la structure nucléaire dans une région de haute déformation. Les faisceaux radioactifs ont été produits par la fragmentation d'un faisceau de #7#8kr sur une cible de #N#A#TNI, grace au nouvel équipement SISSI. Une méthode de purification basée sur l'épluchage des ions secondaires a été utilisée avec succès pour la première fois, et les masses du #7#0SE et du #7#1SE ont été mesurées. Afin d'améliorer la résolution en masse pour des noyaux plus lourds, une autre méthode a été développée, utilisant le second cyclotron du GANIL (CSS2) comme un spectromètre de haute résolution. Une expérience visant à mesurer les masses d'isobares A = 100 au voisinage du noyau doublement magique #1#0#0SN a été réalisée avec succès, en recourant a cette technique originale. Des ions secondaires de #1#0#0AG, #1#0#0CD, #1#0#0IN ET #1#0#0SN ont été produits par la réaction de fusion-évaporation #5#0CR+#5#8NI et simultanément accélérés dans le cyclotron CSS2. La masse du #1#0#0CD et, pour la première fois, celles de #1#0#0IN ET #1#0#0SN ont été déterminées par rapport a la masse de #1#0#0AG prise comme référence. Ces résultats ont été compares a plusieurs prédictions théoriques et ouvrent la discussion sur des considérations de symétrie spin-isospin

Dans cette these, nous avons etudie les proprietes optiques non lineaires de troisieme ordre de la molecule et du cristal de 4-(n,n diethylamino)-nitrostyrene (deanst). Nous avons fait des mesures d'absorption a deux photons de la molecule de deanst en solution par ellipsometrie kerr. Nous avons modelise le spectre non lineaire ainsi obtenu a partir du spectre d'absorption lineaire et d'un unique parametre: la variation de moment dipolaire entre les etats s#0 et s#1. Nous avons monte un banc z scan qui permet la mesure de l'indice de refraction dependant de l'intensite et de l'absorption non lineaire aux deux longueurs d'onde 1,064 m et 532 nm. Les mesures a 1,064 m en solutions ont montre que la variation d'indice de refraction est dominee par l'effet d'orientation moleculaire et que l'absorption a deux photons est faible a cette longueur d'onde. Les mesures effectuees a 532 nm dans une bande d'absorption a un photon de la solution de deanst mettent en evidence de fortes non-linearites dues a la creation d'une population dans un etat excite. Ces mesures montrent qu'aux concentrations elevees, les molecules isolees ne sont pas les seules a jouer un role dans les proprietes non lineaires des solutions. Les mesures z scan sur le cristal de deanst revelent l'anisotropie de ses proprietes non lineaires. De plus, l'absorption non lineaire n'est pas uniquement interpretable par un phenomene de troisieme ordre et necessite l'intervention d'un coefficient non lineaire supplementaire. L'analyse des non-linearites du cristal de deanst doit etre envisagee dans le cadre d'un modele excitonique: le modele du gaz oriente en considerant une hyperpolarisabilite dominee par l'element tensoriel le long du grand axe de la molecule ne rend pas compte des non-linearites du cristal

This work covers spectroscopic studies of nuclei from different regions of the Segré chart whose properties illustrate the delicate balance between the forces in the atomic nucleus. Studies of nuclei far from stability offer new insights into the complex nucleon many-body problem. In nuclei with equal neutron and proton numbers (N = Z), the unique nature of the atomic nucleus as an object composed of two distinct types of fermions can be expressed as enhanced correlations arising between neutrons and protons occupying orbitals with the same quantum numbers. The bound N = Z nuclei with mass number A &gt; 90 can only be produced in the laboratory at very low cross sections. The related problems of identifying and distinguishing such reaction products and their associated gamma rays have prevented a firm interpretation of their structure even for the lowest excited states until recently. In the present work the experimental difficulties of observation of excited states in the N = Z = 46 nucleus 92Pd have been overcome through the use of a highly efficient, state-of-the-art detector system; the EXOGAM-Neutron Wall-DIAMANT setup, and a prolonged experimental running period. The level spacings in the ground state band of 92Pd give the first experimental evidence for a new spin-aligned neutron-proton (np) paired phase, an unexpected effect of enhanced np correlations for N = Z nuclei in the immediate vicinity of the doubly magic nucleus 100Sn. Excited states in 94Ru and 95Rh nuclei close to the double magic shell  Z = N = 50 have been studied in order to untangle the ambiguity of the spin and the parity of the lowest-lying states. The observed yrast structures are compared to results of large-scale shell model (LSSM) calculations and the strengths of hindered E1 transitions are used as a sensitive test of the LSSM parameters. The effect of single-particle-hole excitations is discussed in terms of the strength of hindered E1 transitions. Excited states of the odd-odd nucleus 162Ta have been observed using the JUROGAM/RITU experimental set-up. This nucleus is located in a transitional region in the nuclide chart which is between near-spherical nuclei and well-deformed nuclei, offering the possibility to study the emergence of collective phenomena and nuclear deformation (in particular the degree of triaxiality). The results, which are interpreted in the framework of the cranked shell model with total Routhian surface calculations, suggest an almost axially symmetric nuclear shape. The energy staggering between the signature partners of the yrast rotational bands has been deduced for eight odd-odd isotopes in the neighborhood of 162Ta nucleus and the special observed feature of signature inversion for these nuclei is discussed.<br><p>QC 20140217</p>

Les etudes en decroissance radioactive donnent acces a l'interaction qui regit le processus de desintegration ainsi qu'a la structure des etats nucleaires mis en jeu. Ce travail de these decrit l'observation des desintegrations de noyaux n = z de masse a > 70. Pour les noyaux n = z impair-impair 7 8y, 8 2nb et 8 6tc ces decroissances ont ete identifiees comme transitions superpermises de type fermi. Les resultats obtenus ouvrent la voie a des mesures plus precises et etendent le domaine de masse actuellement utilise pour modeliser le comportement de l'interaction faible dans le milieu nucleaire. L'observation de la decroissance du noyau n = z pair-pair 7 2kr nous a conduit a constituer la distribution de la force de transition gamow-teller qui donne des indications sur la deformation de l'etat fondamental de cet isotope. Des observations experimentales plus completes ainsi que des developpements des calculs utilises pour interpreter la distribution de la force de transition gamow-teller sont necessaires. Enfin, ce travail de these decrit les developpements et tests d'un prototype de detecteur visant a determiner la contribution des particules dans les distributions en energie observees dans le cristal des detecteurs germanium. Les tests menes en laboratoire montrent que ce prototype, fonctionnant en mode telescope, est capable d'identifier et donc de rejeter 80% des particules emises par une source dont la distribution en energie s'etend jusqu'a 2,3 mev. Les performances tres satisfaisantes de ce prototype demandent maintenant a etre confirmees aupres d'installations experimentales.

Pumiliotoxinas e seus congêneres são compostos isolados da pele de algumas espécies de sapos das famílias Dendrobatidae, Mantellidae, Bufonidae, e Myobatrachidae, apresentando interessantes propriedades farmacológicas. As pumiliotoxinas, embora tóxicas, apresentam consideráveis atividades cardiotônicas, assim, acredita-se que as homopumiliotoxinas, as desmetilpumiliotoxinas e as desidrodesmetilpumiliotoxinas também devam apresentar. Nesse sentido, a síntese destes compostos é de extrema valia para a comunidade científica. As diazocetonas &alpha;,&beta;-insaturadas são intermediários promissores para a síntese rápida e eficiente de diversos tipos de esqueletos químicos, entre eles, a construção do esqueleto indolizidínico presentes nas pumiliotoxinas. Cabe ressaltar que para as diazocetonas &alpha;,&beta;-insaturadas com geometria Z provenientes de amino aldeídos, elas já apresentam a estereoquímica correta para uma direta ciclização para a construção de esqueletos indolizidínicos. Dessa forma, as etapas chaves do trabalho consistiram na preparação de amino aldeídos N-protegidos, na avaliação da reação de Horner-Wadsworth-Emmons para fornecer as diazocetonas &alpha;,&beta;-insaturadas com geometria Z, e na reação de inserção N-H intramolecular para a obtenção do ciclo indolizidínico. Outra parte do trabalho consistiu na síntese de imino açúcares de esqueleto piperidínico com cadeias laterais alifáticas (aplicação na química medicinal) e da (-)-1deoxi-altronojirimicina, utilizando-se a mesma metodologia (uso de diazocetonas &alpha;,&beta;-insaturadas com geometria Z).<br>Pumiliotoxins and their congeners are a class of compounds isolated from the skin of some frogs from the Dendrobatidae, Mantellidae, Bufonidae, e Myobatrachidae families, possessing interesting pharmacological activities (cardiotonic activity in low concentrations). Because of the big number of compounds among these toxins (about 100), synthetic methodologies that provide the preparation of these compounds (as well as analogues) in great amounts and in a fast and efficient way using common intermediates, are very important for application in chemical-biology. The &alpha;,&beta;-unsaturated diazoketones are promising intermediates for the rapid and efficient synthesis of a range of chemical skeletons, among them, the construction of indolizidine skeleton that pumiliotoxins present. It is important to note that &alpha;,&beta;-unsaturated diazoketones with Z geometry (prepared from amino aldehydes) have already the correct stereochemistry for a direct cyclization to construct indolizidine skeletons. The key steps of the work consisted in the preparation of N-protected amino aldehydes, evaluation of Horner-Wadsworth-Emmons reaction in order to obtain &alpha;,&beta;-unsaturated diazoketones with Z geometry, and the intramolecular N-H insertion reaction to provide the indolizidine cycle. Another part of the work consisted in the synthesis of iminosugars with piperidine core and aliphatic side chains (application in medicinal chemistry) and in the synthesis of (-)-1-deoxy-altronojirimycin, applying the same methodology (use of &alpha;,&beta;-unsaturated diazoketones with Z geometry).

A particular literary genre, the exhibition review, forms the subject of this dissertation. It represents one facet of a discourse which began to develop in Britain during the latter years of the eighteenth century. Art historians have become increasingly interested in such criticism, but have usually treated it, not as an historical phenomenon which in itself deserves a full investigation, but as a pool of evidence from which to draw remarks concerning individual artists or works of art It is argued that such a one-dimensional approach is unsatisfactory, but that in attempting to go beyond it, the methodological problems posed by this primary source need to be considered. It is stressed that the building up of a basic corpus of knowledge is very important, and an inventory of identified critics is presented in order to assist this. Some observations on the careers of these critics are given. The exhibition reviews published in two contrasting periodicals, the Sun and The Examiner, form the subjects of case studies. The latter are known to have been penned by Robert Hunt and present no problems of attribution. The former are ascribed to John Taylor and the supporting evidence is put forward. The reviews are compared and it is shown how they differed according to their published contexts, and according to the idiosyncracies of their authors. It is suggested that in spite of these differences, a shared critical idiom was a strong force which led reviewers to make many similar comments. This idiom and the precedents which determined its nature are examined. The ways in which it at once harboured and yet disguised certain ideologies are demonstrated. Evidence which helps to place reviews into a more rounded picture of the past is given in conclusion, including statements which show that contemporaries perceived the press as an important influence on the development of taste.

This thesis aims to study the good gradings of simple finite-dimensional Lie algebras. The Dynkin grading is given as an example of good Z-grading of a semisimple Lie algebra. The main properties of a good Z-grading of a semisimple Lie algebra are proved and all good Z-gradings of gl(n), the Lie algebra of all matrices of order n, are classified. Finally, we extend the definition of good gradings to Lie superalgebras and start studying the good gradings of the Cartan superalgebra W(n). The case of W(2) and W(3) are analyzed.