The magnetic properties, coercivity, Hc, and weight-specific magnetic saturation, CoM, are two important quality characteristics in cemented carbides and ceramic metals, cermets. These properties give information about grain size and binder phase content, and are influenced by the different stages in the sintering process. This master thesis aim to investigate how the magnetic properties in cemented carbides are influenced by the top temperature during sintering and how the sintering processes used for cermets can be optimized in order to gain better magnetic properties in the final products. During the first part of the project, the temperature range investigated was 1380°C–1520°C. The results indicate that Hc in cemented carbides has a strong temperature dependence, where increasing top temperature results in lower Hc. In order to have approval limits for the furnace control pieces that follow the process directives, the limits used today need to become narrower. Furthermore, the results show that CoM also has a temperature dependence, although not as strongly as Hc. During the second part of the project, already existing data of the magnetic properties in four different cermet grades were evaluated. The results indicate that the two sintering processes used in the DDK furnace are generating too high results in Hc and CoM. Optimization tests were conducted and changes implemented in order to gain better results, where the DJ1430 process now has an increased time during the solid state sintering and the DF1480 process now has an increased time during the liquid phase sintering.

The main aim of this thesis was to evaluate the current state of iodine levels in horses from selected farms in South Bohemia. Out of the sample group, no animal with iodine deficiency was detected. Additional objective of this thesis was to assess whether selected horse owners supplement their horses with iodine and what form of supplementation they choose.

Neste trabalho estudamos a influência dos efeitos da saturação de pártons nas seções de choque totais próton-próton e próton--antipróton ($pp(\\bar{p})$), a seção de choque inelástica próton-Ar ($p-Ar$) e fazemos uma previsão para as seções de choque total e inelástica próton-chumbo ($p-Pb$). Para todos estes cálculos e previsões utilizamos duas abordagens completamente distintas onde os efeitos da saturação ou são incluidos nas distribuições de pártons da componente perturbativa de um modelo de minijatos eiconalizado ou são introduzidos através de modelos fenomenológicos com inspiração não-perturbativa, em uma região de momento transversal abaixo da chamada escala de saturação. Embora em cada uma das abordagens utilizadas os resultados não sejam muito distintos, podemos verificar que os efeitos da saturação de pártons conduzem a um crescimento dessas seções de choque mais moderado com a energia da reação e que a inclusão desses efeitos permite uma descrição bastante satisfatória e simultânea dos dados experimentais existentes em colisões próton-próton e próton-Ar. Essas são as principais conclusões deste trabalho. / In this work we study the influence of the parton saturation effects on the proton-proton and proton-antiproton ($pp(\\bar{p})$) total cross sections, the inelastic proton-Air ($p-Air$) cross section and we make a prediction for the proton-Plumbum ($p-Pb$) total and inelastic cross sections. For all these calculus and predictions we use two completely distinct approaches, where the parton saturation effects or are included in the parton distribution functions on the perturbative component of a eikonalized minijet model or are included through of phenomenologic models with non-perturbative inspiration in a region of transversal momentum below of the called saturation scale. Although in each of the approaches used the results aren\'t very distincts, we can verify which the parton saturation effects leads to a more moderated rise of these cross sections with the reaction\'s energy and which the inclusion of these effects permit a very satisfactory and simultaneous description of the experimental data of the proton-proton and proton-Air collisions. These are the main conclusions of this work.

Neste trabalho usamos o Interacting glúon Model (IGM), um modelo que descreve bem o fluxo de energia em colisões hadrônicas, para estudar o espectro de partícula dominante quando são incluídos os efeitos da saturação dos glúons. Os espectros de partícula dominante são obtidos para várias energias do centro de massa (s^1/2), usando funções de distribuição dos glúons com e sem efeitos de saturação. Verificamos que, em qualquer caso, há um \"amolecimento\"do espectro, mas os espectros obtidos com saturação variam mais suavemente com a energia do que os que não incluem saturação. Comparamos nossos resultados com outras estimativas feitas na literatura. / In this work we use the Interacting Gluon Model (IGM), a model that describes quite well the energy flow in hadronic collisions, to study the leading particle spectrum when gluon saturation effects are included. The leading particle spectrum is calculated for several center of mass energies (s^1/2), using gluon distribution functions with and without saturation effects. In both cases the resulting spectrum becomes softer for increasing energies. With saturation the softening is less pronounced than without.

The purpose of this study was to determine if arterial oxygen saturation (SaO2), as measured by a finger pulse oximeter upon rapid arrival to 4260 m, could be predictive of acute mountain sickness (AMS) or summit success on a climb to 5640 m. In total 73 climbers volunteered to participate in the study. After excluding those taking drugs to counteract the effects of AMS and those with missing data, 48 participants (45 male, 3 female) remained. Climbers were transported from 2650 m to the Piedra Grande hut at 4260 m on Pico de Orizaba within 2 hr. After a median time of 10 ± 13 hr at the hut, they climbed toward the summit (5640 m) and returned with a median trip time of 13.3 ± 4.8 hr. The Lake Louise Self-assessment Questionnaire (LLSA) for AMS, heart rate, and SaO2 from a finger pulse oximeter was collected upon arrival at the hut, repeated immediately before the climbers departed for their summit attempts, and immediately upon their return. The presence of AMS was defined as a LLSA score ≥ 3 with a headache and at least one other symptom. Fifty-nine percent of the participants successfully reached the summit. Average SaO2 for all participants at 4260 m prior to their departure for the summit was 84.2 ± 3.8%. Sixty percent of the participants met the criteria for AMS during their ascent. There was not a significant difference (p = .90) in SaO2 between those who experienced AMS (SaO2 = 84.3 ± 3.3%) and those who did not (SaO2 = 84.2 ± 4.2%) during the ascent. Neither was there a significant difference (p = .18) in SaO2 between those who reached the summit (84.8 ± 3.7%) and those who did not (83.3 ± 4.0%). Arterial oxygen saturation does not appear to be predictive of AMS or summit success.

The objectives for the first part of this thesis were to describe changes in oxygen saturation (SpO2) and heart rate (HR) in newly born infants in the delivery room (DR) and to illustrate the changes using centile reference charts. The objective of the second part of the thesis was to investigate whether infants < 29 weeks gestation who receive positive pressure ventilation (PPV), immediately after birth with a T-piece have higher SpO2 measurements at five minutes than infants ventilated with a self inflating bag (SIB). / Study Design. A prospective observational study was used to achieve the first objectives. For the second part of the thesis I coordinated a randomised, controlled trial of two devices used for resuscitation of extremely preterm infants in the DR where the primary outcome measure was SpO2. / Patients and methods. In all studies a Masimo Radical pulse oximeter (PO) was placed on the infant’s right hand/wrist immediately after birth. PO data (oxygen saturation, HR and signal quality) were downloaded every 2 sec and analysed only when the signal had no alarm messages (low IQ signal, low perfusion, sensor off, ambient light). / Results. Observational studies: The dataset to develop the reference range charts included 61,650 data points from 468 infants. Infants had a mean (range) gestational age of 38 (25-42) weeks and birthweight 2970 (625-5135) g. For all 468 infants at one minute the 3rd, 10th, 50th, 90th and 97th centiles were 29%, 39%, 66%, 87% and 92%; at two minutes 34%, 46%, 73%, 91% and 95% and at five minutes 59%, 73%, 89%, 97% and 98%. It took a median of 7.9 (IQR 5.0 to 10) minutes to reach a SpO2 > 90%. SpO2 of preterm infants rose more slowly than that of term infants. At one min the median (IQR) HR was 82 (66 to 138) bpm rising at two min and five min to 151 (112 to 169) bpm and 166 (148 to 176) bpm respectively. In preterm infants, the SpO2 and HR rose more slowly than term infants. / Randomised trial: Forty nine infants were randomly allocated to the T-piece and 50 to the SIB. Ten infants did not receive PPV, 4 (8%) in the T-piece group and 6 (12%) in the SIB group and were not included in the analysis. Forty-one infants received PPV with a T-piece and 39 with a SIB. At 5 minutes after birth there was no significant difference between the mean (SD) SpO2 in the T-piece and SIB groups [50 (31)% vs. 53 (25)%, (p=0.73)]. More T-piece infants received oxygen during DR resuscitation (100% vs. 90%, p=0.04). There was no significant difference between the groups in the use of continuous positive airway pressure (CPAP); endotracheal intubation or administration of surfactant in the DR. Fewer of the T-piece group who left the DR on CPAP were intubated in the first 24 hrs after birth. (7% vs. 23%, p=0.05). / Conclusion. The centile charts developed in this thesis provide a reference range for SpO2 and HR in the first 10 minutes after birth for preterm and term infants. In the randomised trial there was no significant difference in SpO2 at five minutes after birth in extremely preterm infants given PPV with a T-piece or a SIB.

The objectives for the first part of this thesis were to describe changes in oxygen saturation (SpO2) and heart rate (HR) in newly born infants in the delivery room (DR) and to illustrate the changes using centile reference charts. The objective of the second part of the thesis was to investigate whether infants < 29 weeks gestation who receive positive pressure ventilation (PPV), immediately after birth with a T-piece have higher SpO2 measurements at five minutes than infants ventilated with a self inflating bag (SIB). / Study Design. A prospective observational study was used to achieve the first objectives. For the second part of the thesis I coordinated a randomised, controlled trial of two devices used for resuscitation of extremely preterm infants in the DR where the primary outcome measure was SpO2. / Patients and methods. In all studies a Masimo Radical pulse oximeter (PO) was placed on the infant’s right hand/wrist immediately after birth. PO data (oxygen saturation, HR and signal quality) were downloaded every 2 sec and analysed only when the signal had no alarm messages (low IQ signal, low perfusion, sensor off, ambient light). / Results. Observational studies: The dataset to develop the reference range charts included 61,650 data points from 468 infants. Infants had a mean (range) gestational age of 38 (25-42) weeks and birthweight 2970 (625-5135) g. For all 468 infants at one minute the 3rd, 10th, 50th, 90th and 97th centiles were 29%, 39%, 66%, 87% and 92%; at two minutes 34%, 46%, 73%, 91% and 95% and at five minutes 59%, 73%, 89%, 97% and 98%. It took a median of 7.9 (IQR 5.0 to 10) minutes to reach a SpO2 > 90%. SpO2 of preterm infants rose more slowly than that of term infants. At one min the median (IQR) HR was 82 (66 to 138) bpm rising at two min and five min to 151 (112 to 169) bpm and 166 (148 to 176) bpm respectively. In preterm infants, the SpO2 and HR rose more slowly than term infants. / Randomised trial: Forty nine infants were randomly allocated to the T-piece and 50 to the SIB. Ten infants did not receive PPV, 4 (8%) in the T-piece group and 6 (12%) in the SIB group and were not included in the analysis. Forty-one infants received PPV with a T-piece and 39 with a SIB. At 5 minutes after birth there was no significant difference between the mean (SD) SpO2 in the T-piece and SIB groups [50 (31)% vs. 53 (25)%, (p=0.73)]. More T-piece infants received oxygen during DR resuscitation (100% vs. 90%, p=0.04). There was no significant difference between the groups in the use of continuous positive airway pressure (CPAP); endotracheal intubation or administration of surfactant in the DR. Fewer of the T-piece group who left the DR on CPAP were intubated in the first 24 hrs after birth. (7% vs. 23%, p=0.05). / Conclusion. The centile charts developed in this thesis provide a reference range for SpO2 and HR in the first 10 minutes after birth for preterm and term infants. In the randomised trial there was no significant difference in SpO2 at five minutes after birth in extremely preterm infants given PPV with a T-piece or a SIB.

L'objectif de cette thèse est la caractérisation de la porosité de la pâte de ciment partiellement saturée par des ondes ultrasonores. Les corrélations entre les vitesses ultrasonores et la porosité ont été étudiées en se basant à la fois sur les résultats expérimentaux et la modélisation micromécanique. Des mesures expérimentales de vitesses ultrasonores longitudinales et transversales en fonction du rapport eau/ciment et à différents états de saturation ont été réalisées sur la pâte de ciment avec et sans entraîneur d'air. En modélisation micromécanique, les effets de saturation ont été modélisés en supposant que la structure poreuse est formée d'inclusions ellipsoïdales de facteur de forme variable selon le rapport E/C. Afin d'estimer les modules homogénéisés élastique de la pâte de ciment et de pâte de ciment à entraîneur d'air différents modèles micromécaniques ont été étudiés. Les résultats de la modélisation micromécanique ainsi que les résultats expérimentaux ont montré que les vitesses des ondes longitudinales et transversales de la pâte de ciment à l'état sec sont inférieures à ceux de l'état saturé. Cet effet est tout aussi important pour l'ensemble des rapports E/C. Le modèle de Mori-Tanaka a donné la meilleure estimation des résultats expérimentaux mesurés sur la pâte de ciment. Alors que le modèle auto-cohérent a donné la meilleure estimation des propriétés mécaniques et ultrasonores de la pâte de ciment avec entraîneur d'air.Les résultats de ce travail devraient constituer le fondement d'un processus d'inversion et d'amélioration de la détermination de la porosité de la pâte de ciment par les ultrasons en tant que méthodes non destructives

L’influence de l’eau sur les propriétés mécaniques des roches a fait l’objet de peu d’études jusqu’à présent. Or dans de nombreuses situations, la différence entre le comportement mécanique de la roche sèche et saturée en eau peut être appréciable. De nouveaux champs d’application, tels que l’analyse des risques liés à l’après-mine ou les problématiques relatives au stockage souterrain des déchets nucléaires, requièrent actuellement une connaissance plus approfondie de ces aspects. Cette étude expérimentale se propose donc de contribuer à une meilleure compréhension du comportement hydromécanique de matériaux rocheux partiellement saturés. Pour ce faire, la démarche suivie a consisté à se baser sur des techniques et outils bien établis pour les sols (meubles), et à les adapter aux matériaux rocheux. Dans ce contexte, une première étude a été menée sur un matériau rocheux argileux, le schiste de Beringen, et a permis d’évaluer l’influence de la succion pour les états de compression simple. Suite à cette première étude, d’autres états de contrainte ont été envisagés, principalement au moyen de l’essai triaxial. Le contrôle de la succion en cours d’essai a demandé d’importantes transformations au système triaxial déjà disponible au laboratoire. En parallèle, un nouvel équipement, comprenant notamment un contrôle de la succion par la méthode de translation d’axes, a été conçu et mis en service. La suite du programme expérimental a été réalisée sur une roche poreuse et très homogène : le calcaire de Sorcy. A l’état sec, les résultats d’essais triaxiaux et polyaxiaux ont permis la construction de surfaces de charge tridimensionnelles. En plan méridien, comme pour d’autres roches poreuses, la résistance augmente avec la pression de confinement lorsque celle-ci reste assez faible (inférieure à 15 MPa environ) ; le comportement est fragile. Aux confinements plus élevés, le comportement devient ductile. En plan octaédrique, la forme de la surface évolue depuis le triangle jusqu’au cercle dans la partie fragile, puis continue à évoluer vers un triangle (inversé par rapport au premier) dans le domaine ductile. En conditions saturées, un ensemble cohérent de paramètres poroélastiques a été mesuré, parmi lesquels le coefficient de Biot (qui a été évalué à environ 0.85). La variabilité de ces paramètres entre échantillons et en fonction de l’état de contrainte a été examinée. Dans le domaine poroplastique, c’est la contrainte effective de Terzaghi qui se révèle contrôler le comportement mécanique, malgré que le coefficient de Biot soit inférieur à 1. En plan méridien, l’enveloppe obtenue pour le matériau saturé se rapproche de celle du matériau sec, moyennant une normalisation par rapport à sa longueur horizontale. Ceci suggère que la prise en compte des conditions non saturées pourrait se faire, comme souvent pour les sols, par l’ajout d’un axe supplémentaire : la succion. En conditions non saturées, les essais réalisés en conditions isotropes à succion contrôlée montrent une forte augmentation du module d’incompressibilité drainé avec la pression de confinement et une faible augmentation avec la succion. Ceci tend à conforter les hypothèses adoptées.

In this paper, we discuss the global existence of solutions for Chemotaxis models with saturation growth. If the coe±cients of the equations are all positive smooth T-periodic functions, then the problem has a positive T-periodic solution, and meanwhile we discuss here the stability problems for the T-periodic solutions.