京都大学 / 0048 / 新制・課程博士 / 博士(人間健康科学) / 甲第20295号 / 人健博第43号 / 新制||人健||4(附属図書館) / 京都大学大学院医学研究科人間健康科学系専攻 / (主査)教授 高桑 徹也, 教授 藤井 康友, 教授 武藤 学 / 学位規則第4条第1項該当 / Doctor of Human Health Sciences / Kyoto University / DGAM

Texte remanié de: Diss.--Philosophische Fakultät I--Zürich--Universität, 1973. / Bibliogr. p. 17-22. Notes bibliogr. Index.

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第19929号 / 医博第4149号 / 新制||医||1017(附属図書館) / 33015 / 京都大学大学院医学研究科医学専攻 / (主査)教授 武藤 学, 教授 坂井 義治, 教授 森田 智視 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

Die vorliegende Arbeit untersucht elektronische Korrelationseffekte in Realsubstanzen wie Europium-Sulphid (EuS) und Gadolinium-Nitrid (GdN). Es wird dazu eine Kombination von vielteilchentheoretischen Analysen der Spin-Austauschwechselwirkung zwischen itineranten Bandelektronen und lokalisierten 4f-Momenten, durchgefuehrt im Rahmen eines Mehr-Band-Kondo-Gitter-Modells (KLM), mit first-principles (T=0) Bandstrukturrechnungen vorgeschlagen. Die Ein-Teilchen-Energien (hopping-Integrale), die als Energie-Matrix in den Mehr-Band-Hamilton-Operator eingehen, werden einer TB-LMTO-ASA entnommen. Die interessierenden physikalischen Eigenschaften wie die Quasiteilchen-Spektraldichte und die Quasiteilchen-Zustandsdichte werden mit der Bewegu-ngsgleichungs-Methode Greencher Funktionen berechnet. Dazu wird fuer die gesuchte Mehr-Band-Selbstenergie der itinerantenLadungstraeger als Verallgemeinerung des sogenannten Interpolating Selfenergy Approach (ISA) ein Ansatz vorgeschlagen. Es stellt sich heraus, dassdas elektronische Anregungsspektrum durch die Austausch-Kopplung an das lokalisierte Momenten-System eine spektakulaere Temperaturabhaengigkeit aufweist, in Uebereinstimmung mit vorliegenden experimentellen Beobachtungen. Stark temperaturbestimmte Korrelationseffekte werden registriert, z.B. eine mit fallender Temperatur in der ferromagnetischen Phase auftretende Rotverschiebung der unteren Leitungsbandkante in guter Uebereinstimmung mit experimentellen Daten. Um die reinen f-Spin-Korrelationen zu beschreiben, wird eine modifizierte RKKY-Theorie fuer Mehr-Band-Systeme entwickelt, wobei durch Ausmitteln der elektronischen Freiheitsgrade das Mehr-Band KLM auf ein effektives Heisenberg-Modell abgebildet wird. Mit einer RPA-Theorie wird das effektive Heisenberg-Modell auf Aussagen zu zentralen magnetischen Eigenschaften wie Curie-Temperatur und Magnetisierungskurve analysiert. Durch gezielte Variation der Systemparameter wird die Brauchbarkeit des Modells getestet. / This dissertation deals with a combination of many-body evaluation of a spin exchange interaction between the itinerant electrons and localized 4f moments on a periodic lattice, i.e. within the so-called multi-band Kondo lattice model (KLM), and the T=0 first principles calculations in order to study the electronic correlation effects in real materials like Europium Sulphide (EuS) and Gadolinium Nitride (GdN).The single-particle ground state energy or hopping integral acting as an input in the many-body part is obtained using tight binding linear muffin-tin orbital within atomic sphere approximation (TB-LMTO-ASA) program and is a matrix in general. The physical properties of interest like the quasi-particle spectral density and quasi-particle density of states are calculated within the Green function theory and the equation of motion method. In order to do so the required multi-band self-energy of the band electrons istaken as an ansatz, i.e. the so-called interpolating self-energy approach (ISA). The electronic excitation spectrum gets a striking temperature dependence by its exchange coupling to the localized spin system. We observe very strong temperature dependent electronic correlation effects in GdN and the calculated red-shift of the lower conduction band is in close comparison with experiment. In order to determine the pure f-spin correlations, we develop the multi-band modified RKKY theory. The central idea of this theory beingto average out the itinerant electron degrees of freedom from the spin-exchange interaction and map the latter on to an effective Heisenberg model. Using this procedure, we determine the magnetic properties of the system like Curie temperature (within Random Phase Approximation) while calculating the chemical potential and magnetization within a self consistent scheme for various configurations of system parameters.

Diese Arbeit beschäftigt sich mit theoretischen Untersuchung von Oberflächenzuständen in ferromagnetischen Halbleitern. Einleitend wird ein analytisches "tight-binding"-Modell zur Beschreibung der Oberflächenzustände. Es liefert Aussagen zur Existenz von Oberflächenzuständen, zu deren spektralen Gewicht und Position bezüglich der Energie. Das Kondogitter-Modell wird verwendet, um Korrelations- und Temperatureffekte sowie Oberflächenzustände zu beschreiben. Dies erfolgt zunächst für sc-(100)-Modellfilme im Rahmen des sf-Modells. Die temperaturabhängigen der Oberflächenzustände zeigen abhängig vom Ort in der Brillouinzone sowie den "hopping"-Parametern in der Oberfläche sowohl Stoner-artiges als auch "spin-mixing"-Verhalten. Mit wachsender Temperatur werden Lebensdauereffekte in den Spektren sichtbar. Das Kondogitter-Modell (KLM) wird auf die Mehrbandsituation zum df-Modell verallgemeinert, um eine Beschreibung der Prototypen für magnetische Halbleiter EuS und EuO zu erreichen. Durch die Kombination von LDA-Bandstrukturrechnungen mit Vielteilchenrechnungen zum Multiband-KLM ist es gelungen, die ausgeprägte Temperaturabhängigkeit des unbesetzten 5d-Leitungsbandes und das Verhalten der Oberflächenzustände in EuS- und EuO-Filmen realistisch zu beschreiben. Der exakte Grenzfall des Kondogitter-Modells, das magnetischen Polaron (T=0), ermöglicht Kombination von ab-initio-Bandstrukturrechnungen und der Vielteilchentheorie ohne das Auftreten von Doppelzählungen relevanter Wechselwirkungen. Sowohl in EuO als auch in EuS temperaturabhängige Oberflächenzustände beobachtet werden, die im Fall von EuS jedoch schwerer nachzuweisen sind, da sie im Energiebereich des Volumenbandes auftreten. Die für EuS und EuO berechneten Rotverschiebungen sowie die dickenabhängige Magnetisierung von EuS stimmen hervorragend mit experimentellen Befunden überein. Eine Vielzahl von Korrelationseffekten ist mit wachsender Temperatur in den Spektren der unbesetzten Europium-5d-Bänder zu beobachten. / This work is dedicated to the theoretical investigation of surface states in ferromagnetic semiconductors. After the introduction a exact solvable analytical model is presented. It figures out for given conditions if surface states exist, which spectral weight they have, and at which position in energy they can be found. Thereafter the Kondo-Lattice-Model (KLM) is used to describe correlation and temperature effects. The description focuses initially to the sc-(100) model films in the sf-model. The resulting temperature dependent surface states both Stoner behavior and "spin-mixing" behavior dependent on the chosen hopping parameters and the position in the two dimensional Brillouin zone. With increasing temperature (up to Tc) lifetime effects arise in the spectra. In conclusion the KLM is extended to the multi-band situation (df-Model) in order to provide a description of the prototypes of magnetic semiconductor EuS and EuO. We succeed in describing the distinct temperature dependence of the unoccupied 5d-conduction band and the behavior of the surface states in EuS and EuO films realistically by a combination of a LDA band-structure calculation and the manybody theory. The exact limiting case of the KLM (T=0) -the magnetic polaron- allows a combination of a ab-initio band-structure calculation and manybody theory without double counting of any relevant interaction. The presented theory provides numerous results. In EuO and EuS can be found temperature dependent surface states. In case of EuS it''s detection is much more complicated thus the surface state energies are located inside the energy range of the bulk band. The famous redshift in EuS and EuO and the thickness dependent film magnetization of EuS agree very well with the experimental results. A lot of correlation effects are present in the calculated unoccupied Europium 5d bands. With increasing temperature these effects become stronger.

Oesophageal cancer is an aggressive malignancy with an overall five-year survival of 5-10% and two-thirds of patients have irresectable disease at diagnosis. Accurate staging of oesophageal cancer is important as survival closely correlates with the stage of the tumour, nodal involvement and presence of metastases (TNM staging). Endoscopic ultrasonography (EUS) is currently the most reliable modality for providing accurate T and N staging. Depending on findings of the staging, various treatment options including endoscopic, oncological, and surgical treatments may be performed. It was theorised that the development of three-dimensional radial endoscopic ultrasonography would reduce the operator dependence of EUS and provide accurate dimensional and volume measurements to aid planning and monitoring of treatment. This thesis investigates the development of a three dimensional endoscopic ultrasound technique that can be used with the radial echoendoscopes. Various agar-based tissue mimicking material (TMM) recipes were characterised using a scanning acoustic macroscope to obtain the acoustic properties of attenuation, backscatter and speed of sound. Using these results, a number of endoscopic ultrasound phantoms were developed for the in-vitro investigation and evaluation of 3D-EUS techniques. To increase my understanding of EUS equipment, the imaging and acoustic properties of the EUS endoscopes were characterised using a pipe phantom and a hydrophone. The dual ‘single element’ mechanical and ‘multi-element’ electronic echoendoscopes were investigated. Measured imaging properties included dead space, low contrast penetration, and pipe length. The measured acoustic properties included transmitted beam plots, active working frequency and peak pressures. Three-dimensional ultrasound techniques were developed for specific application to EUS. This included the study of positional monitoring systems, reconstruction algorithms and measurement techniques. A 3D-EUS system was developed using a Microscribe positional arm and frame grabber card, to acquire the 3D dataset. A Matlab 3D-EUS toolbox was written to reconstruct and analyse the volumes. The 3D-EUS systems were evaluated on the EUS phantom and in clinical cases. The usefulness of the 3D-EUS systems was evaluated in a cohort of patients, who were routinely investigated by conventional EUS for a variety of upper gastrointestinal pathology. 3D-EUS accurately staged early tumours and provided the necessary anatomical information to facilitate treatment. With regards to more advanced tumours, 3D-EUS was more accurate than EUS in T and N staging. 3D-EUS gave useful anatomical details in a variety of benign conditions such as varicies and GISTs.

L’échoendoscopie thérapeutique occupe une place croissante et incontournable de l’activité médico-chirurgicale en pathologie digestive depuis le développement des sondes sectorielles. Les domaines d’application de cette technique interventionnelle mini-invasive sont de plus en plus nombreux, d’une part en pathologie biliopancréatique et entérale permettant la réalisation d’anastomoses évitant un recours à la chirurgie traditionnelle, et d’autre part en cancérologie digestive car elle permet de délivrer un agent thérapeutique, une source de rayonnement ou des cellules liées au système immunitaire dans une lésion ciblée. L’abord vasculaire est une voie récente et prometteuse de l’échoendoscopie interventionnelle offrant des perspectives thérapeutiques en hépatologie notamment dans le domaine de l’hypertension portale. Ce travail se décompose en trois parties décrivant successivement l’état de l'art des applications de l’échoendoscopie interventionnelle, puis deux travaux originaux expérimentaux : dans un premier temps, le transfert de la technique d’anastomose biliodigestive (réalisée régulièrement dans notre centre) à l’abord vasculaire portosystémique sur animal sain, puis dans un deuxième temps la validité de la technique sur modèle animal de fibrose hépatique. La première série d’expérimentations a permis de mettre au point la technique de création d’un shunt intrahépatique portosystémique par échoendoscopie chez 23 cochons sains, en collaboration avec l’équipe de radiologie vasculaire. Ces procédures ont été réalisées dans une salle de cathétérisme vasculaire expérimentale (laboratoire Caviti) dans le cadre du laboratoire d’accueil ISIT (Image Science for Interventional Techniques, Pr. L. Boyer, Pr. J.-Y. Boire, UMR CNRS/UDA 6284). Les résultats ont été concluants puisque le shunt est apparu faisable dans 91% des cas, fonctionnel dans 81% des cas avec une morbidité de 14,2%. La deuxième série d’expérimentations a permis de valider cette technique d’échoendoscopie chez un modèle porcin de fibrose hépatique par embolisation radiologique, en collaboration avec l’Institut National de Recherche Agroalimentaire de Theix pour la stabulation des animaux. Ce travail multidisciplinaire a permis une collaboration étroite entre endoscopistes, radiologues, chirurgiens viscéraux et anatomopathologistes, s’inscrivant dans une démarche de recherche transversale. Les résultats sont encourageants puisqu’un shunt intrahépatique porto-systémique par échoendoscopie s’est révélé techniquement faisable et fonctionnel sur modèle de fibrose hépatique avec une survie à 7 jours des animaux dans deux tiers des cas. Avant d’envisager une étude princeps chez l’homme, des études complémentaires sont néanmoins nécessaires sur des modèles porcins présentant une fibrose hépatique associée à une hypertension portale en augmentant la durée de stabulation, en homogénéisant la procédure de squelettisation de l’artère hépatique et en adaptant la dose de solution injectée. Cette technique pourrait constituer à terme une alternative en cas d’échec de la technique standard pour complications de l’hypertension portale (shunt intrahépatique portosystémique par voie transjugulaire) chez des patients alors en situation d’impasse thérapeutique. / Therapeutic endoscopic ultrasonography is a growing and essential part of the medical and surgical activity in digestive pathology since the development of sectoral probes. The fields of application of this minimally invasive interventional technique are more and more numerous, on the one hand in biliopancreatic and enteral pathology, allowing the realization of anastomoses without traditional surgery, and on the other hand in digestive oncology, because it makes it possible to deliver a therapeutic agent, a source of radiation or cells linked to the immune system in a targeted lesion. The vascular approach is a recent and promising way of interventional endoscopic ultrasound offering therapeutic perspectives in hepatology, especially in the field of portal hypertension.This work is divided into three parts successively describing the state of the art of the applications of interventional ultrasonoscopy, then two original experimental works: initially, the transfer of the technique of biliodigestive anastomosis (performed regularly in our center ) at the portosystemic vascular approach on healthy animal, then in a second time the validity of the animal model technique of liver fibrosis.The first series of experiments led to the development of the technique for the creation of an intrahepatic shunt portosystemic by echoendoscopy in 23 healthy pigs, in collaboration with the vascular radiology team. These procedures were performed in an experimental vascular catheterization room (Caviti laboratory) as part of the ISIT host laboratory (Image Science for Interventional Techniques, Prof. L. Boyer, Pr. J.-Y.Boire, UMR CNRS / UDA 6284). The results were conclusive since the shunt appeared feasible in 91% of cases, functional in 81% of cases with a morbidity of 14.2%. The second series of experiments validated this endoscopic ultrasound technique in a porcine model of liver fibrosis by X-ray embolization, in collaboration with Theix National Institute for Food Research for Animal Stabling. This multidisciplinary work has allowed close collaboration between endoscopists, radiologists, visceral surgeons and anatomopathologists, as part of a transversal research approach. The results are encouraging since a porto-systemic intrahepatic shunt by endoscopic ultrasonography proved to be technically feasible and functional on a hepatic fibrosis model with a 7-day survival of the animals in two-thirds of the cases. Before considering a primary study in humans, additional studies are nevertheless necessary on porcine models presenting hepatic fibrosis associated with portal hypertension by increasing the duration of stabulation, by homogenizing the procedure of skeletonization of the hepatic artery and by adjusting the dose of injected solution. This technique could eventually be an alternative in case of failure of the standard technique for complications of portal hypertension (intrahepatic portosystemic shunt transjugular) in patients then in a situation of therapeutic impasse.

Submitted by Filipe dos Santos (fsantos@pucsp.br) on 2017-01-10T11:33:22Z No. of bitstreams: 1 Taís Helena Fernandes Dias.pdf: 1789393 bytes, checksum: 1262df4f1eb87b73c026b1b97d0ffeef (MD5) / Made available in DSpace on 2017-01-10T11:33:22Z (GMT). No. of bitstreams: 1 Taís Helena Fernandes Dias.pdf: 1789393 bytes, checksum: 1262df4f1eb87b73c026b1b97d0ffeef (MD5) Previous issue date: 2016-12-12 / This dissertation intends to analyze the poetic production of Portuguese poet Adília Lopes. Based on poetic procedures, our objective is to outline this poet's project and to capture the configuration of the Self that emanates from her text. The question that arises is: To which extend does Adília Lopes' poetry shape the personal experience of the lyric subject with characters and stories, showing the intimacy that exists between them? How do counter fictional and anti-lyrical technique used in Adília Lopes' poetry reveal a mixed and unstable territory in her writings? To answer this question, we discuss how the Self is built from the historical, philosophical, social, cultural and literary point of view. The theoretical framework regarding the Self in literature can be found in authors, such as Lejeune, Barthes, Nietzsche, Novalis, Friedrich, and others. For the poetic procedure characterization we used critical studies by Rosa Maria Martelo and Flora Süssekind, as well as Adília Lopes' short stories and interviews. Her poetry presents a diversity of Selves, a multitude of voices. Each poem seems to use a poetic procedure and sustains the question of who is actually speaking, whether it is the author, the poet, the author-character or the poet-character / Esta dissertação se propõe a analisar a produção poética de Adília Lopes. Pretende delinear, a partir de procedimentos poéticos, o projeto dessa poeta portuguesa, apreendendo as configurações do Eu que emanam de seu texto. Assim problematiza: Até que ponto a poesia de Adília Lopes configura a experiência pessoal do sujeito lírico com personagens e histórias, evidenciando um pacto de intimidade entre eles? Como procedimentos contra-ficcionais e antilíricos, empregados na poesia adiliana, revelam um território misto e instável em sua escrita? Para tanto, tece considerações sobre o acontecimento do Eu em perspectivas: histórica, filosófica, social, cultural, literária. Como fundamentação teórica acerca do Eu na literatura, apoia-se em autores como Lejeune, Barthes, Nietzsche, Novalis, Friedrich, entre outros; para a caracterização dos procedimentos poéticos, utiliza-se dos estudos críticos de Rosa Maria Martelo e Flora Süssekind, assim como das crônicas e das entrevistas de Adília Lopes. Entre as considerações notase que sua poesia apresenta uma diversidade de Eus, caracterizando-se por uma polifonia de vozes. Cada poema parece utilizar um procedimento poético, mantendo sempre a dúvida de quem é que fala: a autora, a poeta, a personagem autora, a personagem poeta

Ett av EU:s främsta syfte är att skapa fri rörelse av kapital. Genom att kontinuerligt reducera handelshinder strävar de efter att skapa lika förutsättningar mellan medlemsstaterna. I och med den globalisering som skett och fortfarande sker blir det allt mer vanligt förekommande att svenska bolag konkurrerar och samverkar med andra europeiska bolag. Mycket har hänt på redovisnings- och revisionsområdet det senaste decenniet vilket har gjort att den svenska lagstiftningen delvis har skrivits om och anpassats efter EG:s direktiv. Internationella redovisningsstandarder har fått stort inflytande på framförallt de stora svenska bolagen. Dessa standarder var ursprungligen anpassade för börsnoterade bolag vilket har medfört att mindre svenska bolag under de senaste åren ålagts orimligt omfattande redovisningsskyldigheter. I november 2004 presenterade Justitiedepartementet en promemoria vilken bland annat avsåg förenklade redovisningsregler. Deras bedömning var att de två gränsvärdena som i dag benämns i ÅRL och BFN bör samordnas till ett gemensamt. Motiveringen till detta var att små och medelstora bolag i större utsträckning bör undantas från betungade regler gällande bokföring och bokslut. Under vintern 2005/2006 har en lag-rådsremiss och en proposition offentliggjorts där remissinstanserna BFN, FAR, SRS m.fl. givit uttryck för sina åsikter. Detta resulterade i att delvärdena i den samordnade gränsvärdet fastställdes till 50 anställda, 25 miljoner kronor i balansomslutning samt 50 miljoner kronor i totala intäkter. Syftet med denna uppsats är att utreda vilka konsekvenser detta får för de små och medelstora bolagen i Sverige. Undersökningen har genomförts ur två perspektiv, dels för att återspegla de generella konsekvenserna med harmoniseringen och dels vilka konsekvenser det samordnade gränsvärdet blir redovisningsmässigt. För att uppnå syftet genomfördes fyra expertintervjuer. Resultatet av dessa var att redovisningsprinciperna blir något förenklade men eftersom förslaget ej trätt i laga kraft ännu är det svårt att peka på konkreta konsekvenser. Dock kan man förutse vissa skillnader avseende bland annat delårsrapportering, balansering av egenupparbetade immateriella anläggningstillgångar och restvärdesavskrivningar. Efter att ha tagit del av respondenternas svar samt vad som sägs i lagrådsremissen kan vi konstatera att förändringarna på flera plan går mot att uppgifter ej är lagstadgade utan snarare styrs av intressenterna. Delårsrapporter är en sådan uppgift, då det ej åligger revisionsplikt på dem ser vi det som en naturlig utveckling att ta bort den lagstadgade uppgiftsskyldigheten för K3 – bolagen. Vidare diskuteras huruvida K2 – blocket kommer innefatta bolag med allt för stora skillna-der i omfattning av verksamhet och hur detta skulle kunna undvikas. Vi föreslår en höjning av K1-blocket från tre till fem miljoner kronor i nettoomsättning där aktiebolag ej ska in-kluderas. Anledningen till detta är att få bort de minsta bolagen ur K2 – blocket genom att fler bolag bör överväga alternativa bolagsformer för att undvika allt för omfattande redovisningsmässiga skyldigheter. Från och med den första januari 2007 träder ett nytt regelverk beträffande redovisningsprinciper i kraft i Sverige. Regelverket är delvis utformat efter EU:s redovisningsdirektiv och är ett steg i harmoniseringen. De bolag som vid årsskiftet skall till-lämpa det nya regelverket är de som ej överskrider det nya 50/25/50 - värdet, dvs. K1 och K2 - bolagen. För större bolag, K3 samt K4, kommer reglerna träda i kraft med det räkenskapsår som påbörjas första januari 2010. / One of EU:s primary purposes is to create freedom of movement for capital. Through continuous reducing of trade obstacles they strive to create equal conditions between the member nations. Through the globalization that has taken place and still is taking place it is increasingly common for Swedish companies to compete and cooperate with European companies. A lot has happened in the accounting and auditor area during the last decade which has forced the Swedish legislation partly to be rewritten and adjusted to EG directives. International accounting standards has had a great deal of influence on the major Swedish companies. These standards are originally adapted for stock exchange introduced companies which in the last couple of years have resulted in unreasonable extensive accounting obligations for smaller Swedish companies. In November 2004 the ministry of Justice presented a memorandum which among other things intended to simplify accounting obligations. Their assessment was that the two threshold values that today are termed in ÅRL and BFN should be coordinated into one common threshold. The motivation for this was that small and medium companies in a greater extent should be able to make exceptions from onerous rules concerning bookkeeping and closure. During the winter 2005/2006 a referral and a government bill was made public where BFN, FAR and SRS gave expression of their opinions. This resulted in that the partial value in the coordinated threshold was established to 50 employees, 25 million in balanced turnover and 50 million in total reve-nue. The purpose of this paper is to investigate which consequences this will have to the small and medium companies in Sweden. The investigation has been carried out through two perspectives, one to reflect the general consequences with the harmonious and also which consequences the coordinated threshold value will bring to the accounts. To reach the pur-pose four expert interviews were carried out. The conclusion of these interviews was that the accounting standards will be a bit more simplified but since the proposal has not yet become legally binding it is hard to point to concrete consequences. We can still predict to a certain extend with respect to among other things; quarterly reports, balancing of non-material internally acquired inventory and depreciation of residual values. After studying the respondents’ answers and the referral we can establish that the changes on several levels will progress to the point of information not being statutory but rather controlled by interest organisations. Quarterly reports are that sort of task, when it is not mandatory audit on this sort of report we can not see any reason not to remove the statu-tory information obligation for the K – 3 companies. The thesis further discusses whether the K2 – block will include companies with much too large differences in the extent of activity and how this should be avoided. We suggest a raise of the K-1 block from three too five million in net turnover, where joint-stock companies not will be included. The reason for this is to get rid of the smallest companies in the K-2 block; more companies should consider alternative company forms to avoid all too extensive accounting obligations. Starting on the first of January 2007, the new regulation concerning accounting principles will take effect in Sweden. The regulations are partly designed according to the EU:s ac-counting directives and are a step in the harmonious direction. Those companies who will apply the new regulation at the turn of the year are those which do not exceed the new 50/25/50 value i.e. K-1 and K-2 companies. For the bigger companies, K-3 and K-4, the new regulation takes effect with the accounting year that starts on the first of January 2010.

This thesis presents an exploration of the photophysics of colloidal semiconductor nanocrystals using both linear and non-linear optical measurement techniques. These optical methodologies are used to follow population dynamics in both singly and multiply excited nanocrystal systems as well as determine material properties of the ensemble. Topics covered in the thesis include, the identification and characterization of bulk-like nanocrystals, study of the fine structure states of the lowest energy exciton, single and multiexciton population dynamics, acoustic phonon modes, elasticity and surface stress properties of a colloidal ensemble in solution.Through linear spectroscopy, the properties of both quantum confined and bulk-like colloidal semiconductor nanocrystals are compared. The identification of a model system of bulk-like nanocrystals with a non-standard absorption profile serves to resolve an ambiguity in literature concerning their characterization. The remainder of the thesis is focused on the size-dependent properties of quantum confined CdSe colloidal nanocrystals. The population dynamics and material properties of these systems are studied using a nonlinear optical technique called transient grating. A third order transient grating measurement with a cross-polarized configuration, which follows the relaxation within the fine structure levels of the lowest energy exciton state, is demonstrated and used to compare systems with different crystal field splittings. Transient grating experiments performed with specific polarization sequences allow for selective observation of the dynamics amongst nearly degenerate levels at room temperature. Cross-polarized transient grating is also used to observe a quantized acoustic phonon mode in a series of nanocrystal samples. The observation of this mode allows experimental determination of the elasticity and surface stress of the nanocrystal ensemble in solution. The anisotropic origin of the acoustic phonon is discussed using a combination of theoretical analysis, modelling and experimental data. In addition, third- and fifth-order transient grating experiments are used to study exciton and multiexciton population relaxation dynamics. The work presented here spans the optical and material properties of quantum confined and `bulk' nanocrystals. This thesis attempts to illustrate the broad scope of the observed behaviour of colloidal nanocrystal systems and to contribute to a greater understanding of their physical properties.