Les fibres optiques dont on façonne la réponse spectrale incorporent des ions luminescents, des ions de terres rares (TR), dans des nanoparticules (NP) formées in situ dans un verre de silice par séparation de phase. Cette ingénierie nécessite de comprendre le lien entre la composition des NP et l’environnement des TR.En Dynamique Moléculaire, les potentiels interatomiques existants pèchent à reproduire la séparation de phase observée expérimentalement. Le mélange xMgO-(1-x)SiO2 présente un domaine où coexistent deux phases mixtes, riche en Mg ou en Si. Une telle séparation de phase ne se modélise qu’avec un potentiel interatomique prenant en compte la ionicité des liaisons, réalisé ici par l’ajustement des charges des Oxygène selon l’environnement local. Ce modèle adaptatif, transférable, permet de suivre pour la 1ère fois la formation de NP amorphes de quelques nm. Mixtes et riches en Mg, elles se séparent d’une matrice riche en Si.Le dopage TR (Er3+ ou Eu3+) montre que leur voisinage dépend de la taille des NP les contenant : plus les NP sont grosses, plus les fractions de TR et de Mg augmentent. Ce voisinage riche en Mg permet à ces TR d’augmenter leur coordinence en Oxygène et elles n’ont plus besoin de s’agréger entre elles pour satisfaire cette tendance naturelle.Une simulation de l’étirage à chaud d’un verre de silice confirme l’existence d’une anisotropie dans la fibre optique, venant de l’orientation persistante des petits anneaux de silice, et se manifeste par une anisotropie élastique. Les effets que ces conditions extrêmes induisent sur les NP seront étudiés ultérieurement.La mise en œuvre d'un modèle de champ cristallin corrélera les modifications de l'environnement des TR avec leur réponse spectrale. / Optical fibers with tailored spectral response are doped with luminescent ions, rare-earth ions (re), embedded in nanoparticles (np) formed in situ in silica glass through a phase separation process. This engineering requires to understand the relation between the np composition and the re environment. In molecular dynamics, the existing interatomic potentials fail to reproduce the phase separation as experimentally observed. The system xmgo-(1-x)sio2 exhibits a domain inside of which two mixed phases coexist, mg-rich either si-rich. Such a phase separation can only be modeled by an interatomic potential that takes into account bond ionicity, and the transferability isEnabled here by the adaptation of oxygen charges according to the local environment. This adaptive model allows for the 1st time to track the formation of amorphous np of few nanometers. Mixed and mg-rich, they separate from a si-rich matrix. The re doping (er3+ or eu3+) shows that re environment depends on the size of the containing np: the bigger it is, the more the proportions of embedded re and mg increase. Thus, this mg-rich environment enables re ions to increase their oxygen coordination and to no more aggregate to each other to satisfy this natural trend. A simulation of the high-temperature drawing of silica-glass confirms the existence of an anisotropy in optical fiber, explained by the persistent orientation that small silica rings acquire in this fiber, and manifests itself by an elastic anisotropy. The nontrivial effects induced on np by these extreme conditions of temperature and stress can be studied later. The crystal-field model can be used to correlate the changes of the re environment with their spectral response.

Background: Sports have a significant impact on people all around the world. Although sport brings a lot of joy, a sense of togetherness, and pride, it also involves ethically difficult issues such as doping. Doping in sports is a growing global concern that jeopardizes sports ethics, values, and integrity (The World Anti-Doping Agency WADA, a). Previous research has mainly approached the topic by understanding athletes’ motivation behind the decision to dope. Hence, there is a growing need to understand athletes’ attitudes and beliefs towards clean sports. Aim: This study aimed to comprehensively understand athletes’ attitudes and beliefs on reaching the top without doping and their beliefs on whether doping affects the results of competitions at the national and international levels. Also, it was examined whether variables such as age, gender, testing history, and sports have any distinguished matter on athletes’ attitudes towards clean sports. Method: A cross-sectional mixed-methods study explored athletes' attitudes and beliefs on clean sports. A total of 73 tested athletes (response rate 14,4%) completed a web-based "Assessments of Doping Control and FINCIS Activities" -survey. Results: In this research, athletes’ age, gender, testing history, and sports did not show any significance concerning athletes' attitudes towards reaching the national and international tops without doping. In the open-ended questions, athletes expressed trust in national-level competitions but had more suspicions about international competitions. Conclusion: The results suggest that the athletes in this research reported positive attitudes and beliefs in competing clean. However, it is challenging to determine whether athletes feel that they need to answer “correctly” and according to the values of clean sports. Therefore, it is important to continue studying athletes’ attitudes and clean sports.

Sports research in the field of social science has shown that regular physical activity leads to wellbeing and positively affects the quality of life. A natural part of being an athlete is learning the functions of the human body, and what’s harmful and destructive, such as drugs (RF 1995). Doping is a constant problem in professional sport. Doping and manipulation of medical preparations in order to maximise performance is one of modern sport’s major problems, according to Blom and Lindroth (1995). I thought it would be interesting to see what the next generation of athletes thinks of doping. The purpose of this survey is to investigate the views on doping among adolescent athletes in ages 15-19. What do they think of it? Are they for or against it? Do they believe that doping is commonly used in elite competition? Would they consider using these substances themselves, if they were legalised? The selection of participants is 130 adolescents in ages 15-19. (83 boys, 47 girls.) All respondents are students at upper secondary sports schools, competing in the following events: Alpine sports, soccer, track and field, ice hockey, biathlon, and cross-country skiing. The foundation “Ren Idrott” has conducted a survey showing that as many as 86,3 percent of the respondents in ages 15-21 believe that doping is commonly or very commonly used in elite sports (RF 2005). The notion that using enhancements is necessary to become world champion did not have much support in this survey. Only 4 % stated that they would use preparations if it guaranteed them the world champion title. A whole 73% believed it would be easy to obtain preparations if one wanted to. Their primary reason to refuse preparationwas the risk of physical injury. A majority of the respondents felt that it is everyone’s individual choice whether to use them.All respondents considered doping in sports unacceptable. 11% of the respondents would however consider using preparations if they were legalised.

Research has centred on multidimensional chromatographic techniques which utilise the high specificity of immunoaffinity chromatography for extraction of analytes from complex biological matrices. On-line immunoaffinity chromatography-high performance liquid chromatography-mass spectrometry (IAC-HPLC-MS) systems (IAC and HPLC coupled via a loop interface) were developed for the confirmatory analysis of the corticosteroids dexamethasone and flumethasone with MS detection. Utilising an atmospheric pressure chemical ionisation (APCI) LC-MS interface, dexamethasone was confirmed in both spiked and post administration equine urine samples, with a detection limit of 0.1 ug 1-l. Detection by quadrupole ion trap mass spectrometry (ITMS) using a particle beam (PB) interface was performed for dexamethasone and flumethasone in post administration equine urine samples with high precision (6.9-7.4 %) with limits of detection in the range 3-4 ug 1-l. Studies were also conducted in this work into the antibody crossreactivity and non-specific binding of corticosteroids on a HEMA bound anti-dexamethasone lAC column. On-line IAC-HPLC and IAC-HPLC-GC have been developed and assessed for the determination of testosterone in equine urine. A novel approach to interfacing lAC with HPLC being achieved using a porous graphitic carbon (PGC) column. The IAC-HPLC system developed was used for sample pre-treatment for combustion isotope ratio mass spectrometry analysis. The IAC-HPLC and IAC-HPLC-GC systems finally being coupled with mass spectrometry to enable confirmation of the endogenous steroid at 0.5 ug 1-l and 1 ug 1-l respectively in stripped equine urine.

Continued scaling of CMOS devices with Si and SixGe1-x down to 22 nm design node or beyond will require the formation of ever shallower and more abrupt junctions with higher doping levels in order to manage the short channel effects. With the increasing importance of surface proximity and stress effects, the lateral diffusion in gate-extension overlap region strongly influences both threshold voltage roll-off degradation and DIBL increase by requiring an optimized abruptness and diffusion for better device performance. Therefore, the detailed understanding of defect-dopant interactions in the disordered and/or strained systems is essential to develop a predictive kinetic model for the evolution of dopant concentration and electrical activation profiles. Our density functional theory calculations provide the guidance for experimental designs to realize ultra-shallow junction formation required for future generations of nano-scale CMOS devices. Few systematic studies in epitaxially-grown SixGe1-x channel CMOS have been reported. The physical mechanisms of boron diffusion in strained SixGe1-x/Si heterojunction layers with different SixGe1-x layer thicknesses and Ge content (>50%) are addressed, especially with high temperature annealing. In addition, the effects of the fluorine incorporated during BF2 implant on boron diffusion are investigated to provide more insight into short channel device design. In this study, we investigate how short channel margins are affected by Ge mole fraction and SixGe1-x layer thickness in a compressively strained SixGe1-x/Si heterojunction PMOS with high temperature annealing. Series resistance characterization in S/D extension region and gate oxide interface trap characterization for Si, SixGe1-x, and Ge nMOSFETs are done. TCAD device simulation is also performed to evaluate which distributions of interface traps will significantly affect the electrical characteristics such as flatband voltage (VFB) shift and threshold voltage (Vth) shift based on capacitance-voltage (CV) and current-voltage (IV) curves. n+/p and p+/n diode structures are studied in order to decouple the electrical characteristics from the gated-diode (GD) MOSFETs. With the extraction of S/D series resistance from various channel lengths, possible reasons for performance degradation in SixGe1-x and Ge nMOSFETs, based on simulations, are proposed. / text

No description available.

The research described in this Dissertation is concerned generally with the exploration of the potential use of lanthanide elements in nanostructured materials for the purpose of modification of the magnetic and optical properties. This is explored through a focus on the development of lanthanide-containing iron oxide nanosystems. Our objectives of producing lanthanide containing nanostructured materials with potentially useful optical and magnetic applications has been achieved through the development of lanthanide-doped Fe3O4 and -Fe2O3 nanoparticles, as well as a unique core-shell magnetic-upconverting nanoparticle system.Necessary background information on nanomaterials, rationale for the study of lanthanide-containing iron oxide nanosystems and context for discussion of the results obtained in each project is provided in the Introduction Chapter. The syntheses of Fe3O4 nanoparticles doped with Eu(III) and Sm(III) are discussed, along with structural characterization and magnetic property investigation of products In Chapter 2. The following Chapter expands the study of lanthanide doping to -Fe2O3, a closely related yet distinct magnetic nanoparticle system. A completely different synthesis is attempted, and comparisons between the two systems are made.The development of novel synthetic methodologies used to create such products has yielded high-quality lanthanide-containing materials and are evidenced by TEM images displaying nearly monodisperse particles in each of our efforts. The modifications to the magnetic properties resulting from lanthanide doping include theobservation of ferromagnetism in the Fe3O4 system and increased magnetic saturation of -Fe2O3 nanoparticles, and are characterized by VSM and the visual observation of magnetic alignment of products. Our efforts towards developing a novel methodology capable of producing high quality Fe3O4 nanoparticles, and subsequent characterization of products, were published in the Journal of the American Chemical Society.Optically active, magnetic, core-shell nanoparticles are investigated in Chapter 4 for the potential uses in diagnosis and treatment of cancer. This multifunctional system uses Fe3O4 as a magnetic core, shelled by upconverting lanthanide-containing nanomaterials, and is rendered biocompatible through encapsulation of the core-shell structure by a silica shell. Added functionality is achieved through amine functionalization of the silica surface, with the goal of coupling the inorganic nanoparticle with drug targeting groups. TEM results indicate successful formation of the core-shell nanoparticles, and expected magnetic and optical properties are shown by visual observation and luminescence spectroscopy, respectively.

No description available.

This thesis presents theoretical studies of the optical and electronic properties of defects in diamond and of the mechanisms of doping graphene. The birefringence of the four petalled defect commonly observed in CVD diamond is explained by four linear arrays of dislocations along ⟨110⟩ directions with ⟨110⟩ Burgers vectors. Such an arrangement of dislocations reproduces the extension and the features of the birefringence patterns observed experimentally. Density functional theory via the AIMPRO code was used to study the electronic and optical properties of different nitrogen-related point defects in diamond. It was found that the zero-phonon luminescence line of the NV− defects can split in the presence of a surface or other NV− defects. Since VNH and VN2 are expected to have similar optical properties, the optical transi- tions for VN2 were used to correct the transitions for VNH calculated by local density approximation. The absorption band at 2.38 eV (520 nm) observed in CVD diamond is then attributed to an internal transition of VNH. The weak zero-phonon line and broad vibronic sidebands for VN− and VN−2 and its absence for VNH− is explained by the large structural change when the defect is excited. Finally, different mechanisms for doping graphene were considered. The calculations predict the electropositive metals, such as Ti and Cr, act as donors, while molecules with strong electron affinity, such as F4-TCNQ, act as acceptors in graphene. An unexpected mechanism of doping graphene was shown by Au which dopes bilayer graphene but not single layer. In the presence of water, electrochemical reactions on the graphene can also lead to p or n-type doping.

The purpose of this thesis is to analyze and criticise actual arrangement of Legal Regulation of doping, predict future development and offer diferent possible solution. This thesis is composed of five chapters. Chapter one is an introductory part and briefly describes problem of abusing performance enhancing substances in elite sport. Following part covers main definition of sport as activity and explain relation between sport and law as well as in 'sports rules' imposed by private organisations as World Anti-Doping Agency or Czech Anti-Doping Committee. The third chapter covers the history of doping, briefly explain the physical efects on human organism and define supportive social factors of doping. Part of third chapter is also exposing hidden danger of taking performance enhancing substances in amateur sport. The third part describes main elements of world antidoping regulation and show how world regulation infulences Czech Legal Regulation. I put emphasis on analysing the World Anti-Doping Code and principle of strict liability wich is based on. Fifth Chapter evaluates findings from fourth chapter and tries to find alternative of approach based on zero tolerance for performance enhancing substances, also this chapter identifies and articulates the principal rationales for the regulation of the doping,...