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STAR FORMATION IN W3—AFGL 333: YOUNG STELLAR CONTENT, PROPERTIES, AND ROLES OF EXTERNAL FEEDBACKJose, Jessy, Kim, Jinyoung S., Herczeg, Gregory J., Samal, Manash R., Bieging, John H., Meyer, Michael R., Sherry, William H. 04 May 2016 (has links)
One of the key questions in the field of star formation is the role of stellar feedback on the subsequent star formation process. The W3 giant molecular cloud complex at the western border of the W4 super bubble is thought to be influenced by the massive stars in W4. This paper presents a study of the star formation activity within AFGL. 333, a similar to 104 M-circle dot cloud within W3, using deep JHK(s) photometry obtained from the NOAO Extremely Wide Field Infrared Imager combined with Spitzer IRAC and MIPS photometry. Based on the infrared excess, we identify 812 candidate young stellar objects (YSOs) in the complex, of which 99 are Class I and 713 are Class II sources. The stellar density analysis of YSOs reveals three major stellar aggregates within AFGL. 333, namely AFGL. 333 Main, AFGL. 333 NW1 and AFGL. 333 NW2. The disk fraction within AFGL. 333 is estimated to be similar to 50%-60%. We use the extinction map made from the H - K-s colors of the background stars and CO data to understand the cloud structure and to estimate the cloud mass. From the stellar and cloud mass associated with AFGL. 333, we infer that the region is currently forming stars with an efficiency of similar to 4.5% and at a rate of similar to 2-3M(circle dot) Myr(-1) pc(-2). In general, the star formation activity within AFGL. 333 is comparable to that of nearby low mass star-forming regions. We do not find any strong evidence to suggest that the stellar feedback from the massive stars of nearby W4 super bubble has affected the global star formation properties of the AFGL. 333 region.
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Les conséquences de la sous-traitance pour le syndicat et la main-d'oeuvre : une étude de cas dans le secteur des pâtes et papierPoirier, Isabelle January 2004 (has links)
Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.
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Research portfolio submitted in part fulfilment of the requirements for the degree of Doctorate in Clinical PsychologyShilling, Hannah January 2017 (has links)
No description available.
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Synthesis and reactivity of phosphorus-boron multiple bondsPrice, Amy Nicole January 2018 (has links)
Phosphorus-boron multiple-bonds are of interest because of their predicted reactivity with small molecules; their potential as reagents for the synthesis of molecules isosteric to carbon analogues which exhibit conjugation; and because they have potential as nucleation sites for the solution-phase synthesis of boron phosphide. Phosphaborenes (RP=BR') have not yet been reported due to their propensity to oligomerise to dimers or trimers, even with bulky and electronically-stabilising substituents upon phosphorus and boron. Base-stabilisation at boron allows the isolation of phosphaborenes by preventing oligomerisation, although this alters the reactivity of the phosphaborene unit. An alternative method of studying phosphaborenes free of base or acid coordination is via their thermal generation from a phosphaborene dimer and subsequent in situ reactions with suitable substrates. Chapter 1 examines the potential uses of phosphaborenes in the context of other low-valent main group molecules. The likely reactivity of phosphorus-boron multiple bonds is discussed in the context of the iminoboranes (RNBR') and the isoelectronic heavier group 14 alkyne and alkene analogues. The use of unsaturated main group fragments to build molecular clusters is considered along with the potential role that phosphorus boron multiple bonds could play in preparing boron phosphide fragments. The uses and methods of preparation of group 13/15 containing molecules exhibiting conjugation are discussed, along with the possibility that phosphaborenes would be useful reagents to prepare new P-B/C-C isosteres. Chapter 2 looks at how base-promoted trimethylsilylchloride elimination can be used to prepare base-stabilised phosphaborenes from suitable precursors (RP(SiMe₃)B(X)R' and the mechanism of these reactions. The reactivity of base-stabilised phosphaborenes with Lewis acids is also examined. Chapter 3 covers how base-promoted (L = base) trimethylsilyl halide abstraction from functionalised precursors ((Me₃Si)₃P·BBr₃) can be harnessed to prepare new functionalised phosphinoboranes ((Me₃Si)₂PB(L)Br₂) and phosphaborenes (Me₃SiP=B(L)Br). A 1-dihydro-2-dibromo functionalised phosphinoborane H₂PB(Br₂)L can be prepared from Me₃Si)₂PB(Br₂)L. A subsequent base-promoted dehydrohalogenation yields the hydro-bromo substituted phosphaborene HP=B(L)Br. Chapter 4 examines the in situ thermal generation of a phosphaborene generated from a phosphaborene dimer and its reactivity with bases and unsaturated organic molecules to prepare 1,2-phosphaboretes and 1,2-phosphaboretanes. Chapter 5 explores the diverse reactivity of the 1,2-phosphaboretes. 1,2- phosphaboretes are capable of FLP-like insertion reactions with an isonitrile and carbon monoxide. They are also ring-opened by the coordination of a Lewis acid or base to phosphorus or boron respectively to give P-B containing butadiene analogues. The reaction of the 1,2-phosphaborete with phenyl acetylene proceeds via an unusual carbon-carbon bond cleavage to generate the first example of a 1,3- phosphaborine benzene analogue, rather than the expected 1,4-phosphaborine.
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Probleme eines Fragebuchs für einen ostfränkischen Dialektatlas (Am Beispiel von Erlach)Krämer, Sabine January 1987 (has links) (PDF)
Ziel der vorliegenden Untersuchung ist es, ausgehend von einer Aufnahme des Lautstandes der Mundart der Bauern und Handwerker von Erlach einen Vorschlag für ein neues Fragebuch zu entwickeln und davon einen Arbeitsbericht zu geben. Dabei wurde zunächst der heutige Stand der Mundart aufgenommen mit allen Neuerungen 5 Störungen und umgangssprachlichen Ausgleichserscheinungen, wobei nur die Mundart der älteren Generation dargestellt wurde. Auf die Probleme, die Sprache der mittleren und jüngeren Generation, wo sich umgangssprachliche Tendenzen stärker bemerkbar machen, darzustellen, werde ich ebenfalls kurz eingehen.
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Effet bilatéral d'une tentative unilatérale de modulation de l'amplitude du tremblement physiologiqueDaneault, Jean-François January 2009 (has links) (PDF)
Introduction: Le tremblement physiologique peut être décrit comme étant des oscillations involontaires des membres; ayant des tendances sinusoïdales. Ces oscillations sont présentes dans tous les membres mais sont de si petite amplitude qu'elles ne peuvent être perçues à l'oeil nu. Les oscillations du tremblement physiologique peuvent être séparées en composantes. Les composantes de basse fréquence sont générées par des forces mécaniques et réflexes alors que la majorité des composantes de haute fréquence sont principalement générées par des oscillations provenant du système nerveux central. Nous avons récemment démontré que l'amplitude du tremblement physiologique de l'index pouvait être volontairement réduite. Ceci nous a donc permis de postuler qu'une influence corticale (i.e. commande volontaire) peut être exercée sur les composantes du tremblement physiologique. La relation entre le tremblement des deux mains a déjà été étudiée afin de déterminer si les oscillations de haute fréquence sont générées par un ou plusieurs oscillateurs centraux. Les résultats de ces études suggèrent que les composantes centrales sont générées par de multiples oscillateurs qui les transmettent de façon unilatérale donc, ces oscillateurs seraient indépendants. Nous avons formulé l'hypothèse qu'une tentative de modulation volontaire de l'amplitude du tremblement physiologique changera la relation entre les oscillateurs en les synchronisant. Ceci résulterait en une augmentation de la cohérence entre les oscillations du tremblement des deux index. Objectif: Vérifier si une tentative de modulation de l'amplitude du tremblement physiologique modifie la relation entre les oscillations. Méthode: Trente cinq droitiers ont accepté de faire partie de cette étude. Le tremblement physiologique a été mesuré sur les index des deux mains à l'aide de lasers de déplacement. L'activité électromyographique de l'extensor digitorum communis et du flexor digitorum superficialis des deux avant-bras a été enregistré pour contrôler l'activité musculaire. La fréquence cardiaque et la respiration ont aussi été enregistrées durant chaque essai pour tenter d'identifier si ces paramètres étaient modifiés durant une tentative de modulation. Trois conditions d'enregistrement ont été utilisées: A) condition témoin; B) condition de modulation de l'amplitude du tremblement; et C) condition de co-contraction. Quatre essais ont été enregistrés pour chaque condition. Résultats: L'amplitude du tremblement physiologique a été significativement réduite lors de la tâche de modulation. De plus, cette réduction a aussi été observée du côté controlatéral. Lors de la condition de co-contraction, l'amplitude du tremblement de l'index droit a significativement augmenté mais pas celle du côté controlatéral. La réduction d'amplitude observée lors de la condition de modulation s'est produite uniquement dans les basses fréquences pour la main dominante alors que pour la main non-dominante, une réduction significative a été démontrée dans toutes les bandes de fréquence. La cohérence entre les oscillations du tremblement lors de la condition témoin dans toutes les bandes de fréquence est faible; ce qui démontre l'indépendance des deux mains. De plus, les résultats ont démontrés que la cohérence lors de la tentative de modulation n'était pas significativement différente de celle de la condition témoin et ce, dans toutes les bandes de fréquence. Donc, lors de la condition de modulation, les deux mains sont restées indépendantes. II est à noté que dans toutes les bandes de fréquence, la cohérence la plus élevée a été observée lors de la condition de cocontraction.
Aucune différence significative entre les conditions n'a pu être observée pour les caractéristiques de fréquence cardiaque telle la fréquence cardiaque moyenne et les intervalles R-R (NN50 et pNN50). De plus, aucune différence significative n'a été observée pour la respiration entre les conditions. Par contre, lorsque les participants sont séparé en deux groupes, soit ceux capable de réduire l'amplitude de leur tremblement physiologique et ceux qui n'en sont pas capable, les résultats démontrent que ceux capables de réduire avaient une respiration plus rapide et plus profonde lors de la condition témoin. Conclusion: Nos résultats confirment que l'amplitude du tremblement physiologique peut être réduite volontairement, et que cette réduction s'est produite bilatéralement. De plus, la basse cohérence lors de la condition témoin confirme que des oscillateurs multiples génèrent le tremblement physiologique. La tentative de modulation n'a cependant pas changé la relation spectrale entre les deux côtés puisque la cohérence est demeurée basse. Donc, une commande centrale pour réduire l'amplitude du tremblement n'augmente pas la synchronisation entre les oscillateurs responsables pour les composantes centrales du tremblement physiologique donc, les oscillateurs ne sont pas reliés entre eux. ______________________________________________________________________________ MOTS-CLÉS DE L’AUTEUR : Tremblement, Bimanuel, Modulation, Laser, Cohérence.
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Neutral and Cationic Main Group Lewis Acids - Synthesis, Characterization and Anion ComplexationHudnall, Todd W. 14 January 2010 (has links)
The molecular recognition of fluoride and cyanide anions has become an
increasingly pertinent objective in research due to the toxicity associated with these
anions, as well as their widespread use. Fluoride is commonly added to drinking water
and toothpastes to promote dental health, and often used in the treatment of osteoporosis,
however, high doses can lead to skeletal fluorosis, an incurable condition. Cyanide is
also an extremely toxic anion, which binds to and deactivates the cytochrome-c oxidase
enzyme, often leading to fatality. The molecular recognition of these anions in water has
proven to be challenging. For fluoride, the anion is small, and thus, efficiently hydrated
(?H�hyd = -504 KJ/mol), making its complexation in aqueous environments particularly
difficult. In addition to being small and efficiently hydrated like the fluoride anion,
cyanide has a pKa(HCN) of 9.3 making its competing protonation in neutral water a further
complication. Recent efforts to complex fluoride and cyanide have utilized
triarylboranes, which covalently bind the anion. Monofunctional triarylboranes display
a high affinity for fluoride with binding constants in the range of 105-106 M-1 in organic
solvents, and chelating triarylboranes exhibit markedly higher anion affinities. These
species, however, remain challenged in the presence of water.
This dissertation focuses on the synthesis and properties of novel Lewis acids
designed for the molecular recognition of fluoride or cyanide in aqueous environments.
To this end, a group 15 element will be incorporated into a main group Lewis acidcontaining
molecule for the purpose of: i) increasing the Lewis acidity of the molecule
via incorporation of a cationic group, and ii) increasing the water compatibility of the
host. Specifically, a pair of isomeric ammonium boranes has been synthesized. These
boranes are selective sensors which selectively bind either fluoride or cyanide anions in water. The study of phosphonium boranes has revealed that the latent Lewis acidity of
the phosphonium moiety is capable of aiding triarylboranes in the chelation of small
anions. Finally, my research shows that Br�nsted acidic H-bond donors such as amides,
when paired with triarylboranes, are capable of forming chelate complexes with fluoride.
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極東ネパールヒマラヤ泥質片麻岩の形成条件Imayama, Takeshi, 今山, 武志 03 1900 (has links)
第22回名古屋大学年代測定総合研究センターシンポジウム平成21(2009)年度報告
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Investigations on the use of main group metal complexes of salen ligands as catalysts for the copolymerization of CO2 and epoxidesBillodeaux, Damon Ray 29 August 2005 (has links)
Current industrial processes for the production of polycarbonates, a thermoplastic valued for commercial applications, leave much to be desired from an environmental viewpoint. Research into alternative methods for production of polycarbonates has focused on the copolymerization of carbon dioxide and epoxides for the benefits of eliminating phosgene as a reagent, and for the economic impact of incorporating CO2 as a low cost C1 feedstock. Early work in this field focused on the use of zinc-derived catalysts, but recent studies indicate that chromium complexes of the salen (N,N-bis-(salicylidene)-1,2-ethylene diimine) family of ligands are far superior to the zinc complexes in terms of reactivity and diminishing the formation of unwanted byproducts.
Concomitant to the studies of chromium salen complexes, investigations of main-group salen metal complexes were carried out. Aluminum complexes were able to produce polycarbonate in the presence of tetrabutyl ammonium salts and neutral Lewis bases. Gallium complexes were essentially inactive for generating any product. Tin(IV) complexes were active for the production of polyether, the result of homopolymerization of epoxide without CO2 insertion. Tin(II) complexes generated the monomeric cyclic carbonate product but no copolymer.
An additional aspect of research relative to this field of study is the development of polymeric materials from several different epoxide monomers. The complex [hydrotris(3-phenyl-pyrazol-1-yl)borate]Cd(II) acetate was used to study the thermodynamics of the binding of a series of potential epoxide monomers to a metal center via 113Cd NMR. Activation of the epoxide by a metal center was found to not play a significant role in the ability of the complex to be subsequently ring-opened for polymerization.
A final relevant area of study involved the synthesis of cadmium analogues of Fe/Zn double metal cyanide (DMC) complexes. Heterogeneous DMCs are well known in patent literature as excellent catalysts for the production of polycarbonates and cyclic carbonates from CO2 and epoxides. Previous studies on homogeneous Fe/Zn DMCs have only provided cyclic carbonate. Cd analogues of these species provide a convenient NMR handle for studies on the activity of the metal centers in presence of an epoxide and by changes to the DMC structure.
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Determinants of Taiwan coporations issuing IPOs abroad--empirical evidence in Hong Kong, Singapore, Thailand, Vietnam and ChinaHuang, Chung-hang 23 June 2008 (has links)
The article is about the factors that influence the Taiwanese businesses¡¦ decision to go abroad for listing. Our data are mainly about the Taiwanese businesses¡¦ in Hong Kong, Singapore, Thailand, Vietnam, Shanghai, and Shenzhen. The requirements of main board listing in Hong Kong and Singapore are strict and those in Thailand and Vietnam are loose. There are higher average economic growth rate and better market return in foreign listing market. Although the new listing number is higher than Taiwan, the stock liquidity is lower than Taiwan except Shanghai and Shenzhen market. As the P/E ratio , foreign market is similar to Taiwan except Shanghai¡B Shenzhen and Thailand markets. Overall, the advantages of Taiwan IPO market are not too many except the liquidity.
As overseas Listing of Taiwanese businesses, we find that shoes companies and growth enterprise will get together in Hong Kong, and the average market values and money- raising ability are higher. In Singapore, the industries of Taiwanese business are widely distributed. Moreover, the industry in Thailand, Vietnam and China are mainly construction and living- related. The founding years before listing of foreign Taiwanese business are longer than those listing in Taiwan. Therefore, Taiwanese businesses display different styles in different listing market.
We divided the influencing factors into macro factors, market factors, industry factors, listing requirement factors and unique factors. We used binary logistic regression as our model and found that the macro factors, the market factors, and listing requirement are related to the Taiwanese businesses¡¦ decisions. When there was higher economic growth rate, higher stock return rate or there were more new listed companies in overseas security markets, more Taiwanese business went abroad for listing. But opposite to our intuition, Taiwanese business did not list in a market with higher P/E ratio. The strict listing requirement did not stop Taiwanese business to list there. Therefore, we think only by lowering the listing requirement will not attract Taiwanese business to come back to Taiwan for listing.
Finally, we command that by setting three different ways of Taiwanese businesses¡¦ listing, reducing the money limit and strengthening the collecting industries in Taiwan, we can attract more overseas business coming back to Taiwan for listing.
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