Ce travail porte sur le comportement du Ra au sein d’un écosystème forestier (Montiers, Meuse). Il s’appuie sur la mesure de plusieurs traceurs isotopiques (déséquilibres radioactifs, rapports 228Ra/226Ra et 87Sr/86Sr) dans les différents compartiments du système eau-sol-plante. Les objectifs étaient : 1) d’étudier la mobilité du Ra et ses ascendants radioactifs entre les fractions minérales séparées d’un profil de sol, 2) d’évaluer le transfert du Ra vers les compartiments eau-plante de l’écosystème, 3) de caractériser le transfert du Ra et son temps de résidence dans la végétation, 4) de réaliser le bilan du cycle biogéochimique du Ra. Ce travail montre une forte redistribution de U, Th et Ra en fonction de leurs affinités respectives avec les différentes fractions minérales du sol. Bien que le Ra soit très fortement associé à la fraction fine (< 2µm) du sol, la végétation (hêtres) semble prélever le Ra des oxydes de fer du sol. Le transfert ultérieur de ce nucléide depuis les racines vers les parties aériennes de l’arbre est moins important que celui des autres alcalino-terreux, aboutissant à un temps de résidence dans la végétation de l’ordre de quelques années (2.6 ± 1.6 ans). Enfin, le cycle biogéochimique du Ra est caractérisé par un flux de dégradation de la litière souterraine plus important que celui lié à la litière de surface, par un apport atmosphérique en Ra négligeable et par un flux d'altération très important, ce dernier ne transitant pas par les solutions de sols gravitaires. Le Ra présent dans ces dernières provient presque exclusivement de la dégradation de la litière. / This work investigates the behaviour of Ra within a forest ecosystem (Montiers, Meuse). It is based on the quantification of several isotopic tracers (U- and Th- series disequilibria, isotopic ratios of 228Ra/226Ra and 87Sr/86Sr) in the different compartments of the water-soil-plant system. The research goals were : 1) to study the mobility of Ra and its radioactive ascendants in the separated mineral fractions of a soil profile, 2) to evaluate the transfer of Ra to the water-plant system, 3) to characterise the transfer of Ra and its residence time onto the vegetation, 4) to realise an account of the biogeochemical cycle of Ra. This work shows a strong redistribution of U, Th and Ra depending on their respective affinities with the different mineral fractions of the soil. Despite being predominantly concentrated in the clay fraction (<2 µm) of the soil, our findings indicate that trees (beeches) mostly extract Ra from the soil’s iron oxides. The subsequent transfer of this nuclide from the roots to the foliage is lesser than that of other alkaline-earth metals, leading to a vegetal residence time on the order of a few years (2.6 ± 1.6 years). Finally, the biogeochemical cycle of Ra is characterised by the degradation flux of fine-roots rather than that of leaves, by a negligible atmospheric input and by a strong weathering rate. Ra presents in the latter originates almost uniquely from litter degradation and does not pass through gravitational soil solutions.

Dipolar couplings are one of the major source of structural information. Due to their dependence on the distance between the nuclei and the angle of orientation of the dipolar vector with respect to the magnetic field, they provide significant insight into the geometry and topology of molecules. As the dipolar interactions are in general present in the solid phase of the compounds, solid state NMR experiments have gained significant popularity and is widely used. Separated Local Field NMR spectroscopy based on cross-polarization technique has been used to measure the heteronuclear dipolar couplings in solid state. However, the technique undergoes many experimental challenges and requires further development. This thesis is concerned mainly with the development of techniques to measure the dipolar couplings accurately in oriented molecules. In this regard, a method for fast data acquisition is also proposed. The first chapter briefly introduces the basics of NMR spectroscopy, methodologies applied for obtaining a high resolution NMR spectrum in the solid state. An introduction to liquid crystals is presented and the nature of NMR interaction in the liquid crystalline phases is described. In chapter-2, a new pulse scheme has been proposed that includes the X-nucleus polarization in the SLF experiments and is shown to provide better sensitivity and resolution. A quantitative analysis with simulation and experimental results are also presented. In chapter-3, the performance of various homonuclear decoupling pulse schemes incorporated into SLF experiments tested on oriented systems are compared. The proposed pulse schemes are shown to provide high resolution spectrum with accurate dipolar coupling measurement for natural abundant samples and for uniformly labeled compounds as well. Theoretical description with simulation and experimental results shown here are found to provide optimum results under several technical complications seen with respect to the conventional methods used for SLF experiments. Chapter-4, an attempt is made to reconstruct 2D J-resolved and 2D- SLF spectra from several 1D experimental data. This is achieved with the help of projection reconstruction method and is shown to provide high resolution 2D spectrum with saving of experimental time by an order of two. Chapter-5, high resolution spectra from SLF experiments under phase alternating pulses and using amplitude and time averaged nutation techniques are shown for accurate dipolar coupling measurement with a dramatic reduction in rf power. This is important as the use of low rf power leads to low sample heating and can be applied suitably for the study of liquid crystals and salty biomolecules. Chapter-6, attempts are made to characterize two novel thiophene based liquid crystals using both solution and solid state NMR spectroscopy. C-H dipolar couplings measured from SLF experiments are mainly used to find the order parameters and geometry of the molecules.

Knowledge of flow separation is very essential for proper understanding of both external and internal aerothermodynamics of bodies. Because of unique flow features such as thick boundary layers, merged shock layers, strong entropy layers, flow separation in the flow field of bodies at hypersonic speeds, is both complex as well as interesting. The problem of flow separation is further complicated at very high stagnation enthalpies because of the real gas effects. Notwithstanding the plethora of information available in open literature even for simple geometric configurations the experimentally determined locations of flow separation and re-attachment points do not match well with the results from the computational studies even at hypersonic laminar flow conditions. In this backdrop the main aim of the present study is to generate a reliable experimental database of classical separated flow features around generic configurations at hypersonic laminar flow conditions. In the present study, flow visualization using high speed camera, surface convective heat transfer rate measurements using platinum thin film sensors, and direct skin friction measurements using PZT crystals have been carried out for characterizing the separated flow field around backward facing step, double cone and double wedge models. The numerical simulations by solving the Navier-Stokes equations have also been carried out to complement the experimental studies. The generic models selected in the present study are simple configurations, where most of the classical hypersonic separated flow features of two-dimensional, axi-symmetric and three dimensional flow fields can be observed. All the experiments are carried out in IISc hypersonic shock tunnel (HST2) at Mach 5.75 and 7.6. For present study, helium and air have been used as the driver and test gases respectively. The high speed schlieren flow visualization is carried out on backward facing step (2 and 3 mm step height), double cone (semi-apex angles of 150/350 and 250/680) and double wedge (semi-apex angles of 150/350) models by using high speed camera (Phantom 7.1). From the visualized shockwave structure in the flow field the flow reattachment point after separation has been clearly identified for backward facing step, double cone and double wedge models at hypersonic Mach numbers while the separation point could not be clearly identified because of the low free stream density in shock tunnels. However the flow visualization studies helped clearly identifying the region of flow separation on the model. Based on the results from the flow visualization studies both the physical location and distribution of platinum thin film gauges was finalized for the heat transfer rate measurements. Surface heat transfer rates along the length of two backward facing step (2 and 3 mm step height) models have been measured using platinum thin film gauges deposited on Macor substrate. The Eckert reference temperature method is used along the flat plate for predicting the heat flux distribution. Theoretical analysis of heat flux distribution down stream of the backward facing step model has been carried out using Gai’s dimensional analysis. The study reveals for the first time that at moderate stagnation enthalpy levels (~2 MJ/kg) the hypersonic separated flow around a backward facing step reattaches rather smoothly without any sudden spikes in the measured values of surface heat transfer rates. Based on the measured surface heating rates on the backward facing step, the reattachment distance was estimated to be approximately 10 and 8 step heights downstream of 2 and 3 mm step respectively at nominal Mach number of 7.6. Convective surface heat transfer experiments have also been carried out on axi-symmetric double cone models (semi-apex angles of 15/35 and 25/68), which is analogous to the Edney’s shock interactions of Type VI and Type IV respectively. The flow is unsteady on the double cone model of 25/68 and measured heat flux is not constant. The heat transfer experiments were also carried out on the three-dimensional double wedge model (semi-apex angles of 15/35). The separation and reattachment points have been clearly identified from the experimental heat transfer measurements. It has been observed that the measured heat transfer rates on the double wedge model is less than the double cone model (semi-apex angles of 150/350) for the identical experimental conditions at the same gauge locations. This difference could be due to the three-dimensional entropy relieving effects of double wedge model. PZT-5H piezoelectric based skin friction gauge is developed and used for direct skin friction measurements in hypersonic shock tunnel (HST2). The bare piezoelectric PZT-5H elements (5 mm × 5 mm with thickness of 0.75 mm) polarized in the shear mode have been used as a skin friction gauge by operating the sensor in the parallel shear mode direction. The natural frequency of the skin friction sensor is ~80 kHz, which is suitable for impulse facilities. The direct skin friction measurements are carried out on flat plate, backward facing step (2 mm step height) and double wedge models. The measured value of skin friction coefficient (integrated over an area of 25 sq. mm; sensor surface area) at a distance of 23 mm from the leading edge of the sharp leading edge backward facing step model is found to be ~ 0.0043 while it decreases to ~ 0.003 at a distance of 43 mm from the leading edge at a stagnation enthalpy of ~ 2MJ/kg. The measured skin friction matches with the Eckert reference temperature within ± 10%. The skin friction coefficient is also measured on the double wedge at a distance of 73 mm from the tip of the first wedge along the surface and is found to be 4.56 × 10-3. Viscous flow numerical simulations are carried out on two-dimensional backward facing step, axi-symmetric double cone and three-dimensional double wedge models using ANSYS-CFX 5.7 package. Navier-Stokes Simulations are carried out at Mach 5.75 and 7.6 using second order accurate (both in time and space) high resolution scheme. The flow is assumed to be laminar and steady throughout the model length except on the double cone (semi-apex angles of 250/680) model configuration, which represents the unsteady flow geometry. Analogous Edney Type VI and Type IV shock interactions are observed on double cone, double wedge (semi-apex angles of 150/350) and double cone (semi-apex angles of 250/680) models respectively from the CFD results. Experimentally measured convective heat transfer rates on the above models are compared with the numerical simulation results. The numerical simulation results matches well with the experimental heat transfer data in the attached flow regions. Considerable differences are observed between the measured surface heat transfer rates and numerical simulations both in the separated flow region and on the second cone/wedge surfaces. The separation and reattachment points can be clearly identified from both experimental measurements and numerical simulations. The results from the numerical simulations are also compared with results from the high speed flow visualization experiments. The experimental database of surface convective heating rates, direct skin friction coefficient and shockwave structure in laminar hypersonic flow conditions will be very useful for validating CFD codes

In the first part of this dissertation, the phenomenon of self-sustained pressure os-cillations due to the flow past a circular, axisymmetric cavity, associated with inline gate valves, was investigated. In many engineering applications, such as flows through open gate valves, there exists potential for coupling between the vortex shedding from the up-stream edge of the cavity and a diametral mode of the acoustic pressure fluctuations. The effects of the internal pipe geometry immediately upstream and downstream of the shal-low cavity on the characteristics of partially trapped diametral acoustic modes were in-vestigated numerically and experimentally on a scaled model of a gate valve mounted in a pipeline that contained convergence-divergence sections in the vicinity of the valve. The resonant response of the system corresponded to the second acoustic diametral mode of the cavity. Excitation of the dominant acoustic mode was accompanied by pressure oscillations, and, in addition to that, as the angle of the converging-diverging section of the main pipeline in the vicinity of the cavity increased, the trapped behavior of the acoustic diametral modes diminished, and additional antinodes of the acoustic pressure wave were observed in the main pipeline. In addition to that, the effect of shallow chamfers, introduced at the upstream and/or downstream cavity edges, was investigated in the experimental system that con-tained a deep, circular, axisymmetric cavity. Through the measurements of unsteady pressure and associated acoustic mode shapes, which were calculated numerically for several representative cases of the internal cavity geometry, it was possible to identify the configuration that corresponded to the most efficient noise suppression. This arrangement also allowed calculation of the azimuthal orientation of the acoustic modes, which were classified as stationary, partially spinning or spinning. Introduction of shallow chamfers at the upstream and the downstream edges of the cavity resulted in changes of azimuthal orientation and spinning behaviour of the acoustic modes. In addition, introduction of splitter plates in the cavity led to pronounced change in the spatial orientation and the spinning behaviour of the acoustic modes. The short splitter plates changed the behaviour of the dominant acoustic modes from partially spinning to stationary, while the long split-ter plates enforced the stationary behaviour across all resonant acoustic modes. Finally, the evolution of fully turbulent, acoustically coupled shear layers that form across deep, axisymmetric cavities and the effects of geometric modifications of the cavity edges on the separated flow structure were investigated using digital particle image velocimetry (PIV). Instantaneous, time- and phase-averaged patterns of vorticity pro-vided insight into the flow physics during flow tone generation and noise suppression by the geometric modifications. In particular, the first mode of the shear layer oscillations was significantly affected by shallow chamfers located at the upstream and, to a lesser degree, the downstream edges of the cavity. In the second part of the dissertation, the performance of aortic heart valve pros-thesis was assessed in geometries of the aortic root associated with certain types of valve diseases, such as aortic valve stenosis and aortic valve insufficiency. The control case that corresponds to the aortic root of a patient without valve disease was used as a reference. By varying the aortic root geometry, it was possible to investigate corresponding changes in the levels of Reynolds shear stress and establish the possibility of platelet activation and, as a result of that, the formation of blood clots. / Graduate / 0541 / 0546 / 0548 / 0986 / alexbn024@gmail.com

In the first part of this dissertation, the phenomenon of self-sustained pressure os-cillations due to the flow past a circular, axisymmetric cavity, associated with inline gate valves, was investigated. In many engineering applications, such as flows through open gate valves, there exists potential for coupling between the vortex shedding from the up-stream edge of the cavity and a diametral mode of the acoustic pressure fluctuations. The effects of the internal pipe geometry immediately upstream and downstream of the shal-low cavity on the characteristics of partially trapped diametral acoustic modes were in-vestigated numerically and experimentally on a scaled model of a gate valve mounted in a pipeline that contained convergence-divergence sections in the vicinity of the valve. The resonant response of the system corresponded to the second acoustic diametral mode of the cavity. Excitation of the dominant acoustic mode was accompanied by pressure oscillations, and, in addition to that, as the angle of the converging-diverging section of the main pipeline in the vicinity of the cavity increased, the trapped behavior of the acoustic diametral modes diminished, and additional antinodes of the acoustic pressure wave were observed in the main pipeline. In addition to that, the effect of shallow chamfers, introduced at the upstream and/or downstream cavity edges, was investigated in the experimental system that con-tained a deep, circular, axisymmetric cavity. Through the measurements of unsteady pressure and associated acoustic mode shapes, which were calculated numerically for several representative cases of the internal cavity geometry, it was possible to identify the configuration that corresponded to the most efficient noise suppression. This arrangement also allowed calculation of the azimuthal orientation of the acoustic modes, which were classified as stationary, partially spinning or spinning. Introduction of shallow chamfers at the upstream and the downstream edges of the cavity resulted in changes of azimuthal orientation and spinning behaviour of the acoustic modes. In addition, introduction of splitter plates in the cavity led to pronounced change in the spatial orientation and the spinning behaviour of the acoustic modes. The short splitter plates changed the behaviour of the dominant acoustic modes from partially spinning to stationary, while the long split-ter plates enforced the stationary behaviour across all resonant acoustic modes. Finally, the evolution of fully turbulent, acoustically coupled shear layers that form across deep, axisymmetric cavities and the effects of geometric modifications of the cavity edges on the separated flow structure were investigated using digital particle image velocimetry (PIV). Instantaneous, time- and phase-averaged patterns of vorticity pro-vided insight into the flow physics during flow tone generation and noise suppression by the geometric modifications. In particular, the first mode of the shear layer oscillations was significantly affected by shallow chamfers located at the upstream and, to a lesser degree, the downstream edges of the cavity. In the second part of the dissertation, the performance of aortic heart valve pros-thesis was assessed in geometries of the aortic root associated with certain types of valve diseases, such as aortic valve stenosis and aortic valve insufficiency. The control case that corresponds to the aortic root of a patient without valve disease was used as a reference. By varying the aortic root geometry, it was possible to investigate corresponding changes in the levels of Reynolds shear stress and establish the possibility of platelet activation and, as a result of that, the formation of blood clots. / Graduate / 0541 / 0546 / 0548 / 0986 / alexbn024@gmail.com

O escoamento estratificado óleo-água é comum na indústria de petróleo, em particular em poços direcionais e oleodutos. Estudos recentes mostram que o fenômeno de transição de padrões de escoamento de fases separadas pode estar relacionado à estrutura ondulatória da interface do escoamento (problema de estabilidade hidrodinâmica). A transição do padrão estratificado ao padrão estratificado com mistura na interface foi estudada por diversos autores sendo que a física envolvida está clara, e o fenômeno ocorre pelo arrancamento de gotículas da crista da onda interfacial. Técnicas baseadas na análise temporal da estabilidade hidrodinâmica para a proposição de critérios de transição são comumente encontradas na literatura. Entretanto, para certas condições de escoamento, foi observado que o padrão de escoamento estratificado muda ao longo da tubulação. O escoamento adentra a tubulação como estratificado ondulado e alguns diâmetros após a entrada ocorre a transição para o padrão bolhas alongadas. Foi também observado que o ponto no espaço em que o fenômeno ocorre varia com a elevação ou decréscimo das velocidades superficiais das fases. Aparentemente, tal fenômeno ocorre devido a efeitos de tensão interfacial e ângulo de contato. O modelo de dois fluidos unidimensional, a teoria da estabilidade hidrodinâmica linear (análise espacial) e dados experimentais das propriedades da onda interfacial são utilizados para estudo do escoamento, levando a um novo critério de transição em função da velocidade da onda interfacial. O fenômeno de transição espacial do padrão estratificado ocorre fora da região delimitada como estável pela teoria linear; assim, efeitos não lineares são predominantes e uma teoria que leve em consideração tais efeitos se faz necessária. O método das características foi utilizado e buscou-se prever o ponto no espaço em que a transição ocorre. O estudo experimental foi realizado em montagem experimental do Laboratório de Engenharia Térmica e Fluidos; dados experimentais permitiram a obtenção de uma nova carta de fluxo óleo-água e propriedades da onda interfacial. As comparações entre dados e previsões dos modelos são encorajadoras. / The stratified oil-water flow pattern is of common occurrence in the petroleum industry, especially in offshore directional wells and pipelines. Previous studies have shown that the phenomenon of flow pattern transition in stratified flow can be related to the interfacial wave structure (problem of hydrodynamic instability). The transition from stratified flow to stratified with mixture at the interface has been studied by several authors and the physics behind the phenomenon has been already explained, basically by the tearing of droplets from the interfacial wave crest. Techniques based on a temporal analysis of the hydrodynamic stability for the proposition of transition criteria are often found in the literature. However, at certain inlet flow conditions, it was observed that the flow pattern changes along the test line. The flow enters the test line as wavy stratified flow and then, several diameters from the pipe inlet, the transition to elongated-bubbles flow occurs. It was also observed that the location where the transition occurs also changes depending on the phases superficial velocities. It seems that this phenomenon occurs due to interfacial tension and contact angle effects. The one-dimensional two-fluid model, linear stability theory (spatial approach) and experimental data of the interfacial wave properties are used to study the flow and a new transition criterion based on the wave celerity is proposed. The stratified-flow spatial transition occurred outside the region delimitated as stable by the linear theory; so nonlinear effects are prominent. The method of characteristics was used as an attempt to predict the point in space at which the transition occurs. The experimental work was done at the experimental facility of the Thermal-fluids Engineering Laboratory; experimental data allowed a new oil-water flow map and interfacial wave properties were acquired. The agreement between data and prediction is encouraging.

The years 2010 and 2011 recorded a number of incidents of natural disasters around the globe. These disasters resulted in death, injuries and loss of family members. Children, a vulnerable group of persons, found themselves caught up in the chaos of the natural disasters. Some children lost family members, others became separated from their families and caregiver(s) as a result of the disaster, and those who were "alone" prior to the natural disasters became completely exposed to serious physical and psychological harm. Yet, every child has the right to a family. States have a duty to protect separated and unaccompanied children. Such protection involves prevention of separation, assessment of the child's situation, registration, documentation, family tracing, verification and reunification, emergency care arrangements, and permanent care arrangements. Based on the premise that every child has a right to grow up in a family environment this dissertation attempts to answer the question: How can separated children and unaccompanied children, in the African context, be protected in the event of natural disasters such that their right to a family is promoted and protected? In so doing, it presents an explanation of the concepts of separated children and unaccompanied children through investigation xii into the practical effects of separation on children. It also presents discussions on the concept "natural disasters" and some of the effects of natural disasters on separated children and unaccompanied children. There is an attempt at defining the concept "family" based on its internal and external constitution and function, and a consideration of the needs which a family should satisfy in a child. Familial rights enjoyed by children are presented and analysed as rights which exist under the canopy of the "right to a family". In line with the Interagency Guiding Principles, the different stages of protection in natural disasters are highlighted and particular attention is given to intercountry adoption and the implications of placing moratoriums on intercountry adoptions at different stages of the intercountry adoption process, following events of natural disasters. The study stresses the need to balance the importance of protecting the child with the need to provide the child with a permanent family. Copyright / Dissertation (LLM)--University of Pretoria, 2012. / Private Law / unrestricted

Numerical modeling of several turbulent nonreacting and reacting spray jets is carried out using a fully stochastic separated flow (FSSF) approach. As is widely used, the carrier-phase is considered in an Eulerian framework, while the dispersed phase is tracked in a Lagrangian framework following the stochastic separated flow (SSF) model. Various interactions between the two phases are taken into account by means of two-way coupling. Spray evaporation is described using a thermal model with an infinite conductivity in the liquid phase. The gas-phase turbulence terms are closed using the k-� model. In the classical SSF (CSSF) approach the effects of turbulent velocity fluctuations of the gas-phase are modeled stochastically to obtain instantaneous gas-phase velocity, which subsequently is used to estimate droplet dispersion and interphase transport rates. However, in the CSSF model, no such effort is made to model the effects of the fluctuations in the gas-phase reactive scalars, namely temperature and species mass fractions. Instead, the mean value of these scalars is used while solving for the droplet governing equations and estimating various interphase source terms. Also, in flamelet model and conditional moment closure (CMC) applications of turbulent sprays, the mixture fraction is defined using conventional definition, which is no longer a conserved quantity due to associated phase change. Therefore, in this thesis a novel mixture fraction based FSSF approach is used to stochastically model the fluctuating temperature and composition of the gas phase. These gas-phase reactive scalars are then used to refine the estimates of the heat and mass transfer rates between the droplets and the surrounding gas-phase. It is assumed that the fluctuations in the gas-phase reactive scalars are inherently associated with the fluctuation of a single conserved scalar, namely instantaneous mixture fraction. Instantaneous value of the gas-phase reactive scalars seen by individual droplets is then estimated from the instantaneous gas-phase mixture fraction, which is obtained as the Weiner process by randomly sampling a known beta-function probability density function (PDF) of the local mixture fraction field. Finally, Favre mean value of the gas-phase scalars are recovered as appropriate moments of the PDF. The present definition of the mixture fraction based on its instantaneous value facilitate exact calculation of the source terms in the transport equation for variance of the mixture fraction, whereas conventional definition leads to terms which require further modeling and simplifications. The present FSSF model also accounts for the possibility of existence of an envelope flame between the droplet and the bulk gas-phase, which greatly increases the heat and mass transfer rates to the droplet. The present model allows us to treat the occurrence of envelope flame separately which is otherwise neglected in the conventional spray combustion models. The FSSF model is implemented into a numerical code, and different well-defined nonreacting and reacting turbulent spray jets are investigated. For the reacting spray jets, single-step irreversible reaction with infinitely fast chemistry is assumed in the body of the flow. In such cases special care must be taken with modeling the upstream boundary condition. This is because the flow from the spray jet nozzle is unreacted and yet it becomes well reacted shortly downstream. Numerical results are compared against experimental measurements as well as with predictions using the CSSF approach. Numerical results from the FSSF and CSSF model are almost identical for the nonreacting spray jets, where the fluctuations in the gas-phase scalars are relatively low. For the reacting sprays, significant differences are found between the results of the FSSF and CSSF models for the reacting spray jets, where the fluctuations in the reactive scalars are high. The FSSF model reasonably predicts many features of the jet spray flames, such as flame length, gas-phase temperature, and spray droplet velocity/diameter distribution; results appear to be close to the experimental measurements. Finally, the combustion characteristics of the reacting spray jets are studied following classical group combustion theory. It shows that these spray jets have external group combustion mode near the nozzle-exit. Transition to internal group combustion takes place at different downstream locations based on the droplet loading and equivalence ratio at the nozzle-exit, whereas single droplet combustion regime is observed near the tip of the visible flame. Another alternate approach to study the combustion behavior of a cloud is proposed based on fraction of droplets having i) no envelope flame, ii) envelope flame, iii) extinguished envelope flame due to high slip velocity, iv) extinguished envelope flame due to droplet diameter being too small, v) both iii) and iv) above. Based on these, different group combustion behavior of the reacting spray jets are interpreted.

The diploma thesis is focused on mechanically separated chicken meat (MSM), which was produced on the machine Baader 601 (soft way of separation) and Lima D (hard way of separation). The history, production, composition and legislation relating to the MSM have been described in the theoretical part. The experiments involving the results of the determination of total solids, total fat, total protein, muscle protein and collagen have been introduced in the experimental part. Bone fragments have been determined by weight and visually after alkaline hydrolysis of samples at elevated, respectively atmospheric pressure. Results have been evaluated with regard to the feedstock and the method of mechanical separation. Values have been compared with data published in the scientific literature and legislative requirements. Data from the experiment confirm high variability and thus different food quality of MSMs, depending on the sort of feedstock used in the production of MSM and the separation method.

The aim of this thesis is to design an exclusion of the road crossing the railway line no.300 with Kaštanová street in Brno. A ring road-based solution is proposed. Planned doubling of railway line, as mentioned in the feasibility study of SJKD, was taken into account. The new railway station Brněnské Ivanovice is designed, which will together with public transport bus services create an interchange station. The project also includes a newly designed routes for pedestrians.