Turbulent heat transfer and coherent vortical structures in gas turbine film cooling

Unsteady coherent structures and turbulent heat transfer in a film cooling flow is studied by using detached eddy simulation (DES). Detailed computations for an inclined jet in crossflow by a single row of 35 degree round holes on a flat plate were performed at blowing ratios of 0.5 and 1.0, and a density ratio of 2.0. The correlation between the coherent vortical structures and the unsteady heat transfer is carefully examined. The instantaneous flow fields and heat transfer distributions are found to be characterized by the formation of large coherent vortical structures. These structures enhance the thermal mixing process and turbulent heat transfer to the wall. From the inspection of both unsteady adiabatic film cooling effectiveness and heat transfer coefficient, these two are found to have substantial local fluctuations due to the large unsteadiness of coherent structures. The fluctuation of the adiabatic effectiveness and heat transfer coefficient, for example, can be as high as 15 and 50 percent of the time-mean value, respectively. It could result in the detrimental effect on film cooling performance.

Measurement and modeling of hyperfine properties in ferroic materials

This thesis presents the results of perturbed angular correlation (PAC) experiments , an experimental technique which measures the hyperfine interaction at probes (radioactive ions implanted in the materials to study), from which one infers local information on an atomic scale. Furthermore, abinitio calculations using density functional theory electronic obtain results that directly complement the experiments, and are also used for theoretical research. These methods were applied in two families of materials. The manganites, with the possible existence of magnetic, charge, orbital and ferroelectric orders, are of fundamental and technological interest. The experimental results are obtained in the alkaline-earth manganites (Ca, Ba, Sr), with special interest due to the structural variety of possible polymorphs. With probes of Cd and In the stability of the probe and its location in a wide temperature range is established and a comparison with calculations allows the physical interpretation of the results. Calculations of hyperfine properties in rare-earth manganites are also presented. The second type of materials in which hyperfine properties were studied are the Manganese pnictides: MnAs, MnSb, and MnBi, compounds in which magnetism is fundamental. The experimental results obtained mainly consider the MnAs compound, whose magneto-structural transition is of great interest. The transition is analyzed in detail with the local resolution characteristic of the technique, obtaining information of the character of the transition also with complementary, more conventional techniques. The last work in this thesis uses only the first principles calculations, continuing the theme of the hyperfine interactions, but this time with respect to ferroelectrics. Several transition metal oxides with perovskite or distorted structures are considered. The electric field gradient which exists due to the quadrupole interaction in nuclei is related to the spontaneous electric polarization, the main quantity measured in ferroelectrics. This study provides a fundamental theoretical basis for previous empirical studies, suggesting new directions for research in ferroelectrics and multiferroics using techniques which measure the electric field gradient.

A governance approach to integrated rural tourism: factors influencing organisational performance and tourism support of local development organisations

Ao longo das últimas três décadas, o envolvimento das comunidades na formulação de políticas locais tem vindo a ganhar cada vez mais atenção como uma abordagem sustentável para o desenvolvimento rural na União Europeia (UE) e no mundo. Emergendo da globalização, novas estruturas de governação têm desafiado a base territorial restricta da autoridade do Estado soberano através do envolvimento de uma rede complexa e de autoorganização de atores governamentais e não-governamentais na tomada de decisões coletivas. A reestruturação territorial e institucional das zonas rurais, associada à expansão da governança rural, ganhou atenção considerável na literatura. No entanto, o potencial de empregar princípios de governança como fatores que determinam as direções de desenvolvimento rural através de desempenho organizacional e apoio no turismo não tem sido amplamente explorado na literatura. Deste modo, o principal objetivo desta tese consiste no emprego de ‘integração’, ‘participação’ e ‘empowerment’ como fatores críticos que influenciam os rumos do desenvolvimento rural (1) através do desempenho organizacional das organizações de governança rural e (2) apoio no turismo de organizações de desenvolvimento rural tendo em vista a validação da abordagem de governança para o turismo integrado. Ao longo deste duplo objectivo geral, a tese é dividida numa componente qualitativa de ‘desempenho’ e numa componente quantitativa de ‘apoio’. Seguindo uma abordagem sistemática baseada num sistema conceptual, foram realizadas 38 entrevistas em profundidade com pessoas chave envolvendo gestores do programa LEADER da UE na Hungria (34% do número total de Grupos de Ação Local [GAL]), seguido por um levantamento de campo transversal realizado através de um sistema de recolha de dados na Internet, tendo resultado em 662 questionários válidos para uma taxa de resposta de 63.6%. Os resultados da componente “desempenho” revelaram padrões na implementação dos princípios de governança, que por sua vez permitiram a identificação de fatores que permitem e restringem o desempenho organizacional. Os resultados da componente “apoio” permitiram destacar que o ponto de vista de redes de desenvolvimento local nos princípios de governança não é homogéneo. Diferenças significativas foram encontradas entre organizações responsáveis pelo planeamento e os grupos de aconselhamento. Contudo, os resultados sugeriram que a dimensão sustentável de turismo rural integrado é um prognosticador da contribuição do turismo para o desenvolvimento global da comunicade e para o apoio do turismo ao longo das redes de desenvolvimento local. Este estudo responde a uma necessidade crescente de investigação, que resulta da proliferação à escala mundial de formações de governança em sistemas de administração pública, tanto no lado dos investigadores como no lado dos praticantes.

Phthalocyanines : interaction with carbon structures and as PDT agents

This dissertation describes the synthesis and characterization of different phthalocyanine (Pc) derivatives, as well as some porphyrins (Pors), for supramolecular interaction with different carbon nanostructures, to evaluate their potential application in electronic nanodevices. Likewise, it is also reported the preparation and biological evaluation of interesting phthalocyanine conjugates for cancer photodynamic therapy (PDT) and microorganisms photodynamic inactivation (PDI). The phthalonitrile precursors were prepared from commercial phthalonitriles by nucleophilic substitution of -NO2, -Cl, or -F groups, present in the phthalonitrile core, by thiol or pyridyl units. After the synthesis of these phthalonitriles, the corresponding Pcs were prepared by ciclotetramerization using a metallic salt as template at high temperatures. A second strategy involved the postfunctionalization of hexadecafluorophthalocyaninato zinc(II) through the adequate substituents of mercaptopyridine or cyclodextrin units on the macrocycle periphery. The different compounds were structurally characterized by diverse spectroscopic techniques, namely 1H, 13C and 19F nuclear magnetic resonance spectroscopies (attending the elemental composition of each structure); absorption and emission spectroscopy, and mass spectrometry. For the specific photophysical studies were also used electrochemical characterization, femtosecond and raman spectroscopy, transmission electron and atomic force microscopy. It was highlighted the noncovalent derivatisation of carbon nanostructures, mainly single wall carbon nanotubes (SWNT) and graphene nanosheets with the prepared Pc conjugates to study the photophysical properties of these supramolecular nanoassemblies. Also, from pyridyl-Pors and ruthenium phthalocyanines (RuPcs) were performed Por-RuPcs arrays via coordination chemistry. The results obtained of the novel supramolecular assemblies showed interesting electron donor-acceptor interactions and might be considered attractive candidates for nanotechnological devices. On the other hand, the amphiphilic phthalocyanine-cyclodextrin (Pc-CD) conjugates were tested in biological trials to assess their ability to inhibit UMUC- 3 human bladder cancer cells. The results obtained demonstrated that these photoactive conjugates are highly phototoxic against human bladder cancer cells and could be applied as promising PDT drugs.

Ferroelectric : CNTs structures fabrication for advanced functional nano devices

This work is about the combination of functional ferroelectric oxides with Multiwall Carbon Nanotubes for microelectronic applications, as for example potential 3 Dimensional (3D) Non Volatile Ferroelectric Random Access Memories (NVFeRAM). Miniaturized electronics are ubiquitous now. The drive to downsize electronics has been spurred by needs of more performance into smaller packages at lower costs. But the trend of electronics miniaturization challenges board assembly materials, processes, and reliability. Semiconductor device and integrated circuit technology, coupled with its associated electronic packaging, forms the backbone of high-performance miniaturized electronic systems. However, as size decreases and functionalization increases in the modern electronics further size reduction is getting difficult; below a size limit the signal reliability and device performance deteriorate. Hence miniaturization of siliconbased electronics has limitations. On this background the Road Map for Semiconductor Industry (ITRS) suggests since 2011 alternative technologies, designated as More than Moore; being one of them based on carbon (carbon nanotubes (CNTs) and graphene) [1]. CNTs with their unique performance and three dimensionality at the nano-scale have been regarded as promising elements for miniaturized electronics [2]. CNTs are tubular in geometry and possess a unique set of properties, including ballistic electron transportation and a huge current caring capacity, which make them of great interest for future microelectronics [2]. Indeed CNTs might have a key role in the miniaturization of Non Volatile Ferroelectric Random Access Memories (NVFeRAM). Moving from a traditional two dimensional (2D) design (as is the case of thin films) to a 3D structure (based on a tridimensional arrangement of unidimensional structures) will result in the high reliability and sensing of the signals due to the large contribution from the bottom electrode. One way to achieve this 3D design is by using CNTs. Ferroelectrics (FE) are spontaneously polarized and can have high dielectric constants and interesting pyroelectric, piezoelectric, and electrooptic properties, being a key application of FE electronic memories. However, combining CNTs with FE functional oxides is challenging. It starts with materials compatibility, since crystallization temperature of FE and oxidation temperature of CNTs may overlap. In this case low temperature processing of FE is fundamental. Within this context in this work a systematic study on the fabrication of CNTs - FE structures using low cost low temperature methods was carried out. The FE under study are comprised of lead zirconate titanate (Pb1-xZrxTiO3, PZT), barium titanate (BaTiO3, BT) and bismuth ferrite (BiFeO3, BFO). The various aspects related to the fabrication, such as effect on thermal stability of MWCNTs, FE phase formation in presence of MWCNTs and interfaces between the CNTs/FE are addressed in this work. The ferroelectric response locally measured by Piezoresponse Force Microscopy (PFM) clearly evidenced that even at low processing temperatures FE on CNTs retain its ferroelectric nature. The work started by verifying the thermal decomposition behavior under different conditions of the multiwall CNTs (MWCNTs) used in this work. It was verified that purified MWCNTs are stable up to 420 ºC in air, as no weight loss occurs under non isothermal conditions, but morphology changes were observed for isothermal conditions at 400 ºC by Raman spectroscopy and Transmission Electron Microscopy (TEM). In oxygen-rich atmosphere MWCNTs started to oxidized at 200 ºC. However in argon-rich one and under a high heating rate MWCNTs remain stable up to 1300 ºC with a minimum sublimation. The activation energy for the decomposition of MWCNTs in air was calculated to lie between 80 and 108 kJ/mol. These results are relevant for the fabrication of MWCNTs – FE structures. Indeed we demonstrate that PZT can be deposited by sol gel at low temperatures on MWCNTs. And particularly interesting we prove that MWCNTs decrease the temperature and time for formation of PZT by ~100 ºC commensurate with a decrease in activation energy from 68±15 kJ/mol to 27±2 kJ/mol. As a consequence, monophasic PZT was obtained at 575 ºC for MWCNTs - PZT whereas for pure PZT traces of pyrochlore were still present at 650 ºC, where PZT phase formed due to homogeneous nucleation. The piezoelectric nature of MWCNTs - PZT synthesised at 500 ºC for 1 h was proved by PFM. In the continuation of this work we developed a low cost methodology of coating MWCNTs using a hybrid sol-gel / hydrothermal method. In this case the FE used as a proof of concept was BT. BT is a well-known lead free perovskite used in many microelectronic applications. However, synthesis by solid state reaction is typically performed around 1100 to 1300 ºC what jeopardizes the combination with MWCNTs. We also illustrate the ineffectiveness of conventional hydrothermal synthesis in this process due the formation of carbonates, namely BaCO3. The grown MWCNTs - BT structures are ferroelectric and exhibit an electromechanical response (15 pm/V). These results have broad implications since this strategy can also be extended to other compounds of materials with high crystallization temperatures. In addition the coverage of MWCNTs with FE can be optimized, in this case with non covalent functionalization of the tubes, namely with sodium dodecyl sulfate (SDS). MWCNTs were used as templates to grow, in this case single phase multiferroic BFO nanorods. This work shows that the use of nitric solvent results in severe damages of the MWCNTs layers that results in the early oxidation of the tubes during the annealing treatment. It was also observed that the use of nitric solvent results in the partial filling of MWCNTs with BFO due to the low surface tension (<119 mN/m) of the nitric solution. The opening of the caps and filling of the tubes occurs simultaneously during the refluxing step. Furthermore we verified that MWCNTs have a critical role in the fabrication of monophasic BFO; i.e. the oxidation of CNTs during the annealing process causes an oxygen deficient atmosphere that restrains the formation of Bi2O3 and monophasic BFO can be obtained. The morphology of the obtained BFO nano structures indicates that MWCNTs act as template to grow 1D structure of BFO. Magnetic measurements on these BFO nanostructures revealed a week ferromagnetic hysteresis loop with a coercive field of 956 Oe at 5 K. We also exploited the possible use of vertically-aligned multiwall carbon nanotubes (VA-MWCNTs) as bottom electrodes for microelectronics, for example for memory applications. As a proof of concept BiFeO3 (BFO) films were in-situ deposited on the surface of VA-MWCNTs by RF (Radio Frequency) magnetron sputtering. For in situ deposition temperature of 400 ºC and deposition time up to 2 h, BFO films cover the VA-MWCNTs and no damage occurs either in the film or MWCNTs. In spite of the macroscopic lossy polarization behaviour, the ferroelectric nature, domain structure and switching of these conformal BFO films was verified by PFM. A week ferromagnetic ordering loop was proved for BFO films on VA-MWCNTs having a coercive field of 700 Oe. Our systematic work is a significant step forward in the development of 3D memory cells; it clearly demonstrates that CNTs can be combined with FE oxides and can be used, for example, as the next 3D generation of FERAMs, not excluding however other different applications in microelectronics.

La mise en registre automatique des surfaces acquises à partir d’objets déformables

La mise en registre 3D (opération parfois appelée alignement) est un processus de transformation d’ensembles de données 3D dans un même système de coordonnées afin d’en aligner les éléments communs. Deux ensembles de données alignés ensemble peuvent être les scans partiels des deux vues différentes d’un même objet. Ils peuvent aussi être deux modèles complets, générés à des moments différents, d’un même objet ou de deux objets distincts. En fonction des ensembles de données à traiter, les méthodes d’alignement sont classées en mise en registre rigide ou non-rigide. Dans le cas de la mise en registre rigide, les données sont généralement acquises à partir d’objets rigides. Le processus de mise en registre peut être accompli en trouvant une seule transformation rigide globale (rotation, translation) pour aligner l’ensemble de données source avec l’ensemble de données cible. Toutefois, dans le cas non-rigide, où les données sont acquises à partir d’objets déformables, le processus de mise en registre est plus difficile parce qu’il est important de trouver à la fois une transformation globale et des déformations locales. Dans cette thèse, trois méthodes sont proposées pour résoudre le problème de mise en registre non-rigide entre deux ensembles de données (représentées par des maillages triangulaires) acquises à partir d’objets déformables. La première méthode permet de mettre en registre deux surfaces se chevauchant partiellement. La méthode surmonte les limitations des méthodes antérieures pour trouver une grande déformation globale entre deux surfaces. Cependant, cette méthode est limitée aux petites déformations locales sur la surface afin de valider le descripteur utilisé. La seconde méthode est s’appuie sur le cadre de la première et est appliquée à des données pour lesquelles la déformation entre les deux surfaces est composée à la fois d’une grande déformation globale et de petites déformations locales. La troisième méthode, qui se base sur les deux autres méthodes, est proposée pour la mise en registre d’ensembles de données qui sont plus complexes. Bien que la qualité que elle fournit n’est pas aussi bonne que la seconde méthode, son temps de calcul est accéléré d’environ quatre fois parce que le nombre de paramètres optimisés est réduit de moitié. L’efficacité des trois méthodes repose sur des stratégies via lesquelles les correspondances sont déterminées correctement et le modèle de déformation est exploité judicieusement. Ces méthodes sont mises en oeuvre et comparées avec d’autres méthodes sur diverses données afin d’évaluer leur robustesse pour résoudre le problème de mise en registre non-rigide. Les méthodes proposées sont des solutions prometteuses qui peuvent être appliquées dans des applications telles que la mise en registre non-rigide de vues multiples, la reconstruction 3D dynamique, l’animation 3D ou la recherche de modèles 3D dans des banques de données.

Modeling resting-state functional networks when the cortex falls asleep: local and global changes.

The transition from wakefulness to sleep represents the most conspicuous change in behavior and the level of consciousness occurring in the healthy brain. It is accompanied by similarly conspicuous changes in neural dynamics, traditionally exemplified by the change from "desynchronized" electroencephalogram activity in wake to globally synchronized slow wave activity of early sleep. However, unit and local field recordings indicate that the transition is more gradual than it might appear: On one hand, local slow waves already appear during wake; on the other hand, slow sleep waves are only rarely global. Studies with functional magnetic resonance imaging also reveal changes in resting-state functional connectivity (FC) between wake and slow wave sleep. However, it remains unclear how resting-state networks may change during this transition period. Here, we employ large-scale modeling of the human cortico-cortical anatomical connectivity to evaluate changes in resting-state FC when the model "falls asleep" due to the progressive decrease in arousal-promoting neuromodulation. When cholinergic neuromodulation is parametrically decreased, local slow waves appear, while the overall organization of resting-state networks does not change. Furthermore, we show that these local slow waves are structured macroscopically in networks that resemble the resting-state networks. In contrast, when the neuromodulator decrease further to very low levels, slow waves become global and resting-state networks merge into a single undifferentiated, broadly synchronized network.

Ear acupuncture and fMRI: a pilot study for assessing the specificity of auricular points.

In recent years research explored different acupuncture stimulation techniques but interest has focused primarily on somatic acupuncture and on a limited number of acupoints. As regards ear Acupuncture (EA) there is still some criticism about the clinical specificity of auricular points/areas representing organs or structures of the body. The aim of this study was to verify through (Functional magnetic resonance imaging) fMRI the hypothesis of EA point specificity using two auricular points having different topographical locations and clinical significance. Six healthy volunteers underwent two experimental fMRI sessions: the first was dedicated to the stimulation of Thumb Auricular Acupoint (TAA) and the second to the stimulation of Brain Stem Auricular Acupoint (BSAA). The stimulation of the needle placed in the TAA of the left ear produced an increase in activation bilaterally in the parietal operculum, region of the secondary somatosensory area SII. Stimulation of the needle placed in the BSAA of the left ear showed a pattern that largely overlapped regions belonging to the pain matrix, as shown to be involved in previous somatic acupuncture studies but with local differences in the left amygdala, anterior cingulate cortex, and cerebellum. The differences in activation patterns between TAA and BSAA stimulation support the specificity of the two acupoints. Moreover, the peculiarity of the regions involved in BSAA stimulation compared to those involved in the pain matrix, is in accordance with the therapeutic indications of this acupoint that include head pain, dizziness and vertigo. Our results provide preliminary evidence on the specificity of two auricular acupoints; further research is warranted by means of fMRI both in healthy volunteers and in patients carrying neurological/psychiatric syndromes.

Setting boundaries: brain dynamics of modal and amodal illusory shape completion in humans.

Normal visual perception requires differentiating foreground from background objects. Differences in physical attributes sometimes determine this relationship. Often such differences must instead be inferred, as when two objects or their parts have the same luminance. Modal completion refers to such perceptual "filling-in" of object borders that are accompanied by concurrent brightness enhancement, in turn termed illusory contours (ICs). Amodal completion is filling-in without concurrent brightness enhancement. Presently there are controversies regarding whether both completion processes use a common neural mechanism and whether perceptual filling-in is a bottom-up, feedforward process initiating at the lowest levels of the cortical visual pathway or commences at higher-tier regions. We previously examined modal completion (Murray et al., 2002) and provided evidence that the earliest modal IC sensitivity occurs within higher-tier object recognition areas of the lateral occipital complex (LOC). We further proposed that previous observations of IC sensitivity in lower-tier regions likely reflect feedback modulation from the LOC. The present study tested these proposals, examining the commonality between modal and amodal completion mechanisms with high-density electrical mapping, spatiotemporal topographic analyses, and the local autoregressive average distributed linear inverse source estimation. A common initial mechanism for both types of completion processes (140 msec) that manifested as a modulation in response strength within higher-tier visual areas, including the LOC and parietal structures, is demonstrated, whereas differential mechanisms were evident only at a subsequent time period (240 msec), with amodal completion relying on continued strong responses in these structures.

Free-breathing inner-volume black-blood imaging of the human heart using two-dimensionally selective local excitation at 3 T.

Black-blood fast spin-echo imaging is a powerful technique for the evaluation of cardiac anatomy. To avoid fold-over artifacts, using a sufficiently large field of view in phase-encoding direction is mandatory. The related oversampling affects scanning time and respiratory chest motion artifacts are commonly observed. The excitation of a volume that exclusively includes the heart without its surrounding structures may help to improve scan efficiency and minimize motion artifacts. Therefore, and by building on previously reported inner-volume approach, the combination of a black-blood fast spin-echo sequence with a two-dimensionally selective radiofrequency pulse is proposed for selective "local excitation" small field of view imaging of the heart. This local excitation technique has been developed, implemented, and tested in phantoms and in vivo. With this method, small field of view imaging of a user-specified region in the human thorax is feasible, scanning becomes more time efficient, motion artifacts can be minimized, and additional flexibility in the choice of imaging parameters can be exploited.

Traditional local medicines in the republic of Palau and non-communicable diseases (NCD), signs of effectiveness.

ETHNOPHARMACOLOGICAL RELEVANCE: The aim of this survey was to describe which traditional medicines (TM) are most commonly used for non-communicable diseases (NCD - diabetes, hypertension related to excess weight and obesity) in Pacific islands and with what perceived effectiveness. NCD, especially prevalent in the Pacific, have been subject to many public health interventions, often with rather disappointing results. Innovative interventions are required; one hypothesis is that some local, traditional approaches may have been overlooked. MATERIALS AND METHODS: The method used was a retrospective treatment-outcome study in a nation-wide representative sample of the adult population (about 15,000 individuals) of the Republic of Palau, an archipelago of Micronesia. RESULTS: From 188 respondents (61% female, age 16-87, median 48,), 30 different plants were used, mostly self-prepared (69%), or from a traditional healer (18%). For excess weight, when comparing the two most frequent plants, Morinda citrifolia L. was associated with more adequate outcome than Phaleria nishidae Kaneh. (P=0.05). In case of diabetes, when comparing Phaleria nishidae (=Phaleria nisidai) and Morinda citrifolia, the former was statistically more often associated with the reported outcome "lower blood sugar" (P=0.01). CONCLUSIONS: Statistical association between a plant used and reported outcome is not a proof of effectiveness or safety, but it can help select plants of interest for further studies, e.g. through a reverse pharmacology process, in search of local products which may have a positive impact on population health.

The micromorphology of Paleoseismic soft sediment deformation structures in glacial deposits from three sample sites in Scotland /

The nature of this research is to investigate paleoseismic deformation of glacial soft sediments from three sampling sites throughout the Scottish Highlands; Arrat's Mills, Meikleour and Glen Roy. The paleoseismic evidence investigated in this research will provide a basis for applying criteria to soft sediment deformation structures, and the trigger mechanisms that create these structures. Micromorphology is the tool used in this to investigate paleoseismic deformation structures in thin section. Thin section analysis, (micromorphology) of glacial sediments from the three sampling sites is used to determine microscale evidence of past earthquakes that can be correlated to modem-day events and possibly lead to a better understanding of the impact of earthquakes throughout a range of sediment types. The significance of the three sampling locations is their proximity to two major active fault zones that cross Scotland. The fault zones are the Highland Boundary Fault and the Great Glen Fault, these two major faults that parallel each other and divide the country in half Sims (1975) used a set of seven criteria that identified soft sediment deformation structures created by a magnitude six earthquake in Cahfomia. Using criteria set forth by Sims (1975), the paleoseismic evidence can be correlated to the magnitude of the deformation structures found in the glacial sediments. This research determined that the microstructures at Arrat's Mill, Meikleour and Glen Roy are consistent with a seismically induced origin. It has also been demonstrated that, even without the presence of macrostructures, the use of micromorphology techniques in detecting such activity within sediments is of immense value.

Effects of intracerebroventricular bombesin administration on local cerebral glucose utilization in the restrained and unrestrained rat

Intracerebroventricular (ICV) administration of bombesin (BN) induces a syndrome characterized by stereotypic locomotion and grooming, hyperactivity and sleep elimination, hyperglycemia and hypothermia, hyperhemodynamics, feeding inhibition, and gastrointestinal function changes. Mammalian BN-like peptides (MBNs), e.g. gastrin-releasing peptide (GRP), Neuromedin C (NMC), and Neuromedin B (NMB), have been detected in the central nervous system. Radio-labeled BN binds to specific sites in discrete cerebral regions. Two specific BN receptor subtypes (GRP receptor and NMB receptor) have been identified in numerous brain regions. The quantitative 2-[14C]deoxyglucose ([14C]20G) autoradiographic method was used to map local cerebral glucose utilization (LCGU) in the rat brain following ICV injection of BN (vehicle, BN O.1Jlg, O.5Jlg). At each dose, experiments were conducted in freely moving or restrained conditions to determine whether alterations in cerebral function were the result of BN central administration, or were the result of BN-induced motor stereotypy. The anteroventral thalamic nucleus (AV) (p=O.029), especially its ventrolateral portion (AVVL) (plocalized alteration in cerebral metabolism within parts of the anterior thalamus, which is the principle relay in the limbic circuitry. BN effects were also observed in IGr, Mi, SCh, and ME. Effects of restraint were found in LOVL, LOOM, and LG. It is suggested that increased LCGU in AV and AVVL may be the result of functional change in the limbic circuitry and the hypothalamus caused by BN receptor functional modification. In IGr, increased LCGU following BN administration is considered to be mainly the result the activation of NMB receptor, a subtype of BN receptors. In SCh, increased LCGU is believed to be caused both by BN effects on the thalamic, the hypothalamic, and the limbic functions and by activation of GRP receptor, another BN receptors subtype found in SCh. In ME, increased LCGU is suggested to be caused by BN effects on the hypothalamic functions, especially those related to the neuroendocrine functions. None of the alterations seen in these regions reflects the emission of stereotyped motor behaviors. Rather, they reflect a direct influence of BN central administration upon functioning of the cerebral regions influenced by BN administration. The restraint effects seen in LO, including LOOM and LOVL, are suggested to be the result of altered behavioral expression. The restraint effects seen in LG is suggested to be the result of reduced locomotion.

Reduced local energy calculations on X¹Sigmaâ ½gHâ and 1¹S He /|nGerald F. Thomas. -- 260 St. Catharines [Ont.] : Dept. of Chemistry, Brock University,

The one-electron reduced local energy function, t ~ , is introduced and has the property < tL)=(~>. It is suggested that the accuracy of SL reflects the local accuracy of an approximate wavefunction. We establish that <~~>~ <~2,> and present a bound formula, E~ , which is such that where Ew is Weinstein's lower bound formula to the ground state. The nature of the bound is not guaranteed but for sufficiently accurate wavefunctions it will yield a lower bound. ,-+ 1'S I I Applications to X LW Hz. and ne are presented.

Selected topics in fast atom bombardment (FAB) mass spectrometry a)specially designed probe tips and ion generation, b)structures of vitamin B6 schiff base complexes

This thesis can be broken down into two sections. Section one is a study . of the ionization mechanisms and the ion source optimization for Fast Atom Bombardment (FAB) ionization. For this study, several specially designed probe tips were created and tested under various experimental conditions. The aIm of this section is to understand the operating characteristics of a FAB IOn source better. The second section involves the study of several Vitamin B6 Schiff Base complexes using both positive and negative ion FAB MS. This section is an exploration of the usefulness of FAB MS as a structure probe for the metalcoordination complexes of Vitamin B6.