Дисертації з теми "FMS BARRIERS"

Background:The family business is one of Sweden’s most common business forms, making up 90% of all firms and institutions. Also, it accounts for more than a third of GDP. So, it plays a vital role in the economy in Sweden. However, most of the family businesses are relatively small. Purpose:This paper aims to explore and understand the internal growth barriers to the small Swedish family business. Method:A qualitative method inspired by the inductive approach was conducted through semi-structured interviews with five owners of small family businesses in Sweden. The data were analyzed through three steps of general analytical procedure, which are (1) data reduction, (2) data displays, (3) conclusion and verification. Conclusion:This study concludes several internal growth barriers that affect the small Swedish family business: having only revenue goals, long-term growth goals, no written form of goals, family-oriented goals, unawareness of owner to change the firm’s structure during the growth, owner’s tendency to control all activities, owner prefers to keep the business smaller to keep control, the owner has more than one role and task, shortage of competencies and skills, unqualified successors and family members are welcome, lack of robots and Knowledge, owners have another job, different tasks, and roles, family business offers services of high quality that need time, selecting the oldest son to take over regardless of his competencies, employees’ attitude towards obeying a female owner, successors have no interest in taking over, no successors, rivalry among siblings and conflict of their interest, high arguments, different goals of family members from different generations, employ the first non-family member employee, employed more people, fear that non-family employees are less interested in FB or that more employees lead to loss of control, not able to employ more people and finally risk-avoiding behaviour. These barriers resulted in: hindering strategic changes in the needed time, innovation changes in the market obstructed, goals are forgotten, lack of competencies and skills, increases workload and challenges for the male manager, not responding to the market changes quickly, impossible to manage everything effectively, decrease control, not employing needed employees, responsibilities and roles on the owner increase, decrease integrity and harmony in the family, and finally, not developing the products, assisting more customers, and focusing on the growth. Consequently, lead to selling the firm and not keep it for a long time, slow growth, do no maximize potential growth, growth affected negatively, growth hindered, stay in the same size, avoid growth chances, or miss growth opportunities.

Graphitic materials, thanks to the lamellar structure and chemical stability, are of particular interest to realize barriers against the degradation of surface properties induced by water. Many studies showed that water could be a source of degradation of surface properties. To develop a method to overcome the problem related to the deterioration of the surface it is fundamental to study the water- material interaction. For this reason, in this thesis, the water-surface interaction of graphitic- materials and the use of graphitic materials as impermeable barriers against water were explored. Different experimental set up were realized to study the liquid-gas-solid interaction, such as time evolution of the sessile water drop contact angle, captive bubble contact angle and contact angle measurements in a controlled atmosphere. Moreover, a method of deposition of protective graphene-based films using a Meyer rod to apply graphene-inks onto a surface was developed. To understand the intrinsic wettability of graphitic materials a detailed study of the gas-liquid-solid interactions of graphite was conducted in a wide range of experimental conditions. The surface chemical properties and morphology were studied by X-ray photoelectron spectroscopy (XPS), profilometry and atomic force microscopy(AFM), sessile drop contact angle, captive bubble and secondary emission microscopy (SEM). The results of the gas-liquid–surface interaction study indicated that HOPG surface was sensitive to experimental conditions like airborne contamination and the presence of gases. Similarly, a detailed study of the interaction of water with PDMS surface in various experimental conditions (in the air and immersed in water) were conducted. The findings showed that when PDMS was immersed in water, its surface changed. In fact, the volume of air bubbles in contact with the surface of PDMS increased by increasing immersion time in the water. The experimental results indicated that such dynamic evolution of the air bubbles was related to the rearrangement of surface polymer chains via the migration of the polar groups. This phenomenon induced a degradation of the surface properties of PDMS when it is immersed in water. When graphene monolayer was added to PDMS surface, it acted as a barrier against water, suppressing the dynamic evolution of the bubble. We studied the protective properties also of graphene-based films deposited on lead (Pb). We observed that Pb surface degradation occurred when Pb was in contact with a drop of water. The results showed that degradation of Pb surface in contact with water happened very rapidly but graphene-based films, in particular, graphene oxides films, were able to reduce degradation of the surface significantly.

Graphitic materials, thanks to the lamellar structure and chemical stability, are of particular interest to realize barriers against the degradation of surface properties induced by water. Many studies showed that water could be a source of degradation of surface properties. To develop a method to overcome the problem related to the deterioration of the surface it is fundamental to study the water- material interaction. For this reason, in this thesis, the water-surface interaction of graphitic- materials and the use of graphitic materials as impermeable barriers against water were explored. Different experimental set up were realized to study the liquid-gas-solid interaction, such as time evolution of the sessile water drop contact angle, captive bubble contact angle and contact angle measurements in a controlled atmosphere. Moreover, a method of deposition of protective graphene-based films using a Meyer rod to apply graphene-inks onto a surface was developed. To understand the intrinsic wettability of graphitic materials a detailed study of the gas-liquid-solid interactions of graphite was conducted in a wide range of experimental conditions. The surface chemical properties and morphology were studied by X-ray photoelectron spectroscopy (XPS), profilometry and atomic force microscopy(AFM), sessile drop contact angle, captive bubble and secondary emission microscopy (SEM). The results of the gas-liquid–surface interaction study indicated that HOPG surface was sensitive to experimental conditions like airborne contamination and the presence of gases. Similarly, a detailed study of the interaction of water with PDMS surface in various experimental conditions (in the air and immersed in water) were conducted. The findings showed that when PDMS was immersed in water, its surface changed. In fact, the volume of air bubbles in contact with the surface of PDMS increased by increasing immersion time in the water. The experimental results indicated that such dynamic evolution of the air bubbles was related to the rearrangement of surface polymer chains via the migration of the polar groups. This phenomenon induced a degradation of the surface properties of PDMS when it is immersed in water. When graphene monolayer was added to PDMS surface, it acted as a barrier against water, suppressing the dynamic evolution of the bubble. We studied the protective properties also of graphene-based films deposited on lead (Pb). We observed that Pb surface degradation occurred when Pb was in contact with a drop of water. The results showed that degradation of Pb surface in contact with water happened very rapidly but graphene-based films, in particular, graphene oxides films, were able to reduce degradation of the surface significantly.

Beyond the opportunities offered by nanotechnology research, there is a great need of studies aimed at understanding the harmful effects of general exposure to nanomaterials. My Ph.D. project aimed to be part of this evaluation, focusing on the interaction and the induction of possible toxic effects of two fibrous nanomaterials (asbestos and carbon nanotubes) at two critical internal biological barriers: the pleura and the placenta. The work is carried out by using advanced microscopy (µXRM and XRF) based on synchrotron radiation and other microscopes (SEM and AFM), and also conventional molecular analysis (PCR and Sanger sequencing) and advanced spectroscopic measurements (UV-Raman). We conducted biochemical studies by using the advanced X-Ray microscopy and fluorescence (µXRM and XRF) techniques in order to reveal mechanisms of toxicity in human mesothelial (MeT5A) and placental cell lines (BeWo) exposed to carbon nanotubes (raw-SWCNT, purified- and highly purified-SCWCNT) or asbestos (crocidolite fibres). Other microscopes (AFM, atomic force microscopy and SEM, Scanning Electron Microscope) are added in some experiments, to better investigate the morphology and the cell-nanofiber interactions. The results obtained with the combination of microscopic techniques allowed to reveal similar as well as different toxic mechanisms in the two internal barriers. The cells treated with raw-SWCNT and crocidolite fibres compared to the control showed an severe alteration of iron metabolism, which is maximal in the pleural cells and is clearly related to the presence of iron into the fibre. X-ray microscopy images (absorption and phase contrast imaging) confirm that the toxicity of nanomaterials is characterized by membrane damage with vesicle secretion and filipodia formation. In relation to this toxic mechanism quite complex and still unknown we evaluated the presence of intracellular ferritin in treated cells. The results demonstrated that crocidolite and “raw” carbon nanotubes increase the amount of intracellular ferritin in both cell models, while purified and highly purified carbon nanotubes give values comparable to control. The stimulation is clearly lower in placental cells, clearly linked to a different or lower uptake of fibres in these cells, suggesting that this barrier is less vulnerable than the pleura. We also investigated the genetic effects and genetic predisposition to toxicity of nanomaterials (nanotoxicogenomic). Since we have to learn from asbestos, one study investigates the possible genetic predisposition to develop mesothelioma after asbestos exposure by looking for BAP1 gene mutations in 30 cases of mesothdelioma. Sanger sequencing of BAP1 gene in the 30 patients identified one non-synonymous variant and two intronic variants. While Sanger sequencing of cDNA revealed no alternative splicing due to the nucleotide change for each mutations. In silico mutation analysis was performed in a predicted protein structure of BAP1 protein without any significant possible effect of the amino acid change about exonic mutations of patient 9. Finally, MLPA (Multiplex ligation-dependent probe amplification) analysis revealed no significant copy number variations at exonic level in all samples. The last aim of molecular studies was to test the feasibility of UV-Raman (IUVS beamline, Elettra Synchrotron of Trieste) spectroscopy to reveal epigenetic changes at DNA level after nanomaterial exposure. An oxidative environment has been created in vitro by using carbon nanotubes (raw-SWCNT), which contain some impurity in metal traces (iron), and free radicals OH• (derived from H2O2). In this condition the nucleotides (dATP, dCTP, dGTP and dTTP) result in increased susceptibility to oxidative damage. The results demonstrated that UV-Raman spectroscopy is useful to reveal the chemical changes that affect the nitrogenous bases after nanomaterials exposure, providing a “fingerprint” of the oxidative DNA damage.

Thesis (Ph. D.)--University of Oregon, 2007.
Typescript. Includes vita and abstract. Includes bibliographical references (leaves 249-264). Also available for download via the World Wide Web; free to University of Oregon users.

In this thesis, four different Machine Learning models and algorithms have been evaluated in the work of classifying Traffic Control Plans in the City of Helsingborg. Before a roadwork can start, a Traffic Control Plan must be created and submitted to the Traffic unit in the city. The plan consists of information regarding the roadwork and how the work can be performed in a safe manner, concerning both road workers and car drivers, pedestrians and cyclists that pass by. In order to know what safety barriers are needed both the Swedish Association of Local Authorities and Regions (SALAR) and the Swedish Transport Administration (STA) have made a classification of roads to guide contractors and traffic technicians what safety barriers are suitable to provide a safe workplace. The road classifications are built upon two rules; the amount of traffic and the speed limit of the road. Thus real-world problems have shown that these classifications are not applicable to every single case. Therefore, each roadwork must be judged and evaluated from its specific attributes. By creating and training a Machine Learning model that is able to determine if a rigid safety barrier is needed or not a classification can be made based on historical data. In this thesis, the performance of several Machine Learning models and datasets are presented when Traffic Control Plans are classified. The algorithms used for the classification task were Random Forest, AdaBoost, K-Nearest Neighbour and Artificial Neural Network. In order to know what attributes to include in the dataset, participant observations in combination with interviews were held with a traffic technician at the City of Helsingborg. The datasets used for training the algorithms were primarily based on geographical data but information regarding the roadwork and period of time were also included in the dataset. The results of this study indicated that it was preferred to include road attribute information in the dataset. It was also discovered that the classification accuracy was higher if the attribute values of the geographical data were continuous instead of categorical. In the results it was revealed that the AdaBoost algorithm had the highest performance, even though the difference in performance was not that big compared to the other algorithms.

The use of plasmas in aerodynamics has become a recent topic of interest. In particular, over the last ten years, plasma actuation has received much attention as a promising active method for airflow control. Flow control consists of manipulating the properties of a generic moving fluid with the aim of achieving a desired change, but flow dynamics in proximity of a solid object is usually considered, being a consistent and significant issue in many engineering applications, such as engine, automobile or airplane design. Plasma control of airflows along surfaces has been the subject of several experimental studies whose aim was to reduce turbulence, to decrease drag, to enhance airfoil lift or to prevent flow detachment. The fast temporal response and the absence of moving parts are the most promising features from which plasma actuators could benefit. Different types of plasma sources are currently studied as good candidates for plasma actuation, but Dielectric Barrier Discharges (DBDs) are usually preferred, being characterized by the presence of an insulating barrier between the electrodes. This allows the generation of a non-thermal plasma at atmospheric pressure and prevents the discharge from collapsing into an arc. Surface Dielectric Barrier Discharges (SDBDs) are particularly suitable for these kinds of applications, since plasma is created by ionizing a thin portion of air nearby the surface of the dielectric barrier and this can effectively influence the local properties of the boundary layer associated to an external flow. This thesis deals with SDBDs in an asymmetric configuration where one electrode is glued into an insulating material and to other one is exposed to air, so that plasma is created in correspondence of just one side of the dielectric barrier. The buried electrode is connected to the ground, whereas a sinusoidal high-voltage is applied to the exposed one. It has been noticed that, when these discharges are operated in quiescent air, an airflow of several metres per second is observed above the dielectric sheet and near the plasma region. This is usually called ionic wind because the main mechanism responsible for its generation is believed to be momentum transfer from the ions drifting in the discharge electric field to the surrounding fluid, by particle-particle collisions. When the electric field imposed by the voltage difference between the electrodes is sufficiently high, plasma is created and electrical charges are transported through the gap and accumulated on the insulating surfaces. This charge accumulation generates an electric field that locally weakens the external one. When the total electric field falls below the threshold necessary for plasma ignition, the discharge extinguishes. If the voltage imposed to the fed electrode is increased, the discharge can be locally initiated again, and that is the reason why a sinusoidal high-voltage supply is adopted instead of a continuous one. Consequently, the presence of the insulating barrier usually leads to a regime where charge is mainly transported in sub-millimetre regions consisting of current filaments with temporal duration limited to a few tens of nanoseconds. These plasma microdischarges are concentrated into two phase intervals of the sinusoidal voltage supply, when the modulus of the applied voltage difference is high enough and is increasing in time. These two phases of plasma activity are often called Backward Stroke (BD) and Forward Stroke (FD), depending if the high-voltage signal is rising from its minimum to its maximum or decreasing from its maximum to its minimum. This thesis is motivated by the fact new studies focusing on plasma properties and dynamics are required in order to get better and better aerodynamic results, to understand which parameters mainly affect the actuator performances and to validate numerical models trying to forecast the aerodynamic effects induced by the discharge. This has brought to a scientific collaboration between the Centre of Excellence PlasmaPrometeo of University of Milano-Bicocca and the Aerodynamics and Wind Tunnel Department of the aerospace company Alenia Aermacchi. During these years I have studied the properties of these discharges by means of electrical and optical diagnostics (mainly Rogowski coils, capacitive probes, a photomultiplier tube and a thermal camera). With some of them a temporal resolution high enough for studying several characteristics of plasma microdischarges has been achieved. This is important because these strokes manifest as series of current and light pulses, lasting tens of nanoseconds and a few nanoseconds respectively. I have first of all carried out a detailed investigation of the properties of these events and of their evolution in space and time in the course of the FD and BD. It has been pointed out that there are several analogies between the BD and FD, but that not all plasma properties are identical for the two semi-cycles, because of the asymmetrical configuration adopted. These investigations let think that light and current signals give insights about different microdischarge properties. Light is presumably ascribable to electrons that excite nitrogen immediately after the passage of the ionizing wave that initiates the microdischarge. In contrast, the current signal is due to the movement of charges into the plasma channel and thus reflects the microdischarge temporal evolution, rather than its formation. In the following experiments I have thus focused mainly on the electrical properties of plasma microdicharges, with the aim of better understanding which plasma characteristics are responsible for the ionic wind generation and properties. Several SDBDs with different geometrical configurations and operating parameters have been considered. It has been found that both the discharge and ionic wind characteristics are mainly affected by the dielectric thickness, whereas other properties of the SDBD are less decisive. These studies are of practical interest because optimizations of SDBD characteristics are still needed for adopting these discharges as plasma actuators for active flow control. In particular, it has been found that at first the speed of the induced wind increases quite linearly with the voltage amplitude, but then this velocity and thus the aerodynamic effects induced by the discharge tend to saturate. This is particularly evident when thin panels are adopted as dielectric barriers. I thus focused on this topic and I found that an asymmetry in the total charge transported by plasma microdischarges during the backward and forward strokes is favourable for obtaining a ionic wind with a greater velocity, and that the velocity saturation at the highest voltages is associated to a change in discharge regime, which is visible first of all because a pattern of plasma filaments appears superimposed to the more homogeneous plasma. I have thus characterized how this regime transition affects the dynamics of the backward and forward strokes. Three groups of microdischarges have been identified, depending on their temporal duration, and results let think that they don't contribute equally to the electric wind generation. These studies pave the way to a better understanding of the discharge peculiarities and ionic wind formation, with the aim of understanding if an intrinsic limit exists in plasma actuator potentialities or if new optimization strategies are possible. Eventually, I proposed to implement the Background Oriented Schlieren (BOS) technique for the visualization and characterization of the airflow induced by the discharge. The potentialities of this technique have been evaluated in relation to the specifics of the available scientific equipment. The technique has then been proved to be able to visualize density changes induced by plasma. A spatial characterization of the air near the discharge was made in stationary wall jet conditions as well as in the transient period following the discharge ignition when a starting vortex is generated.

This thesis work is divided in two parts: (i) designing and constructing a new ionization chamber with fast response (FastIC) for the study of near- and sub-barrier fusion of exotic systems using the very neutron-rich beams of the SPES facility in construction at the Laboratori Nazionali di Legnaro (LNL) of INFN, and (ii) carrying out, analyzing and interpreting the results of the sub-barrier fusion experiment for the two systems 36S + 50Ti,51V, performed using the FastIC. A new set-up for fusion cross-section measurements, especially designed for the low-intensity beams delivered by the SPES facility, has been developed at the LNL. This new set-up includes a fast IC designed to withstand a high counting rate particle identification for fusion studies involving exotic beams up to 105 pps. The readout of the FastIC was optimised and extensive tests using stable heavy-ion beams demonstrated its ability to operate up to rates of about140 kHz, compared to few kHz of the previous IC chamber. This feature and the much larger solid angle coverage will allow to detect fusion-evaporation residues with an efficiency close to 100%. The new FastIC has been employed for the experimental study of sub-barrier fusion in the 36S + 50Ti, 51V systems. The possible effect of the non-zero spin of 51V ground state on the sub-barrier excitation function and on the shape of the barrier distribution has been investigated. The two excitation functions have been measured down to cross sections of about 20 ub, and it appears that they are very similar to each other. A coupled channels analysis has been performed in order to highlight differences between the two systems, and a modified coupled-channels code was used in order to treat the odd nucleus 51V. The experimental excitation functions and the extracted barrier distributions have been compared to the theoretical predictions. This comparison suggests a small difference between the two systems above the barrier, that might be experimentally observed by measuring the backward-angle quasi-elastic scattering in that energy region.
Il lavoro di tesi si divide in due parti: (i) la progettazione e costruzione di una nuova camera di ionizzazione con risposta veloce (FastIC), per lo studio di processi di fusioni di sistemi esotici ad energie in prossimità e sotto la barriera Coulombiana. Si useranno fasci ricchi di neutroni che saranno forniti dalla facility SPES, in costruzione presso i Laboratori Nazionali di Legnaro (LNL) dell'INFN. La seconda parte della tesi riguarda la realizzazione, l’analisi e l’interpretazione dei risultati dell'esperimento di fusione sotto barriera dei due sistemi 36S + 50Ti, 51V, eseguito utilizzando il nuovo rivelatore FastIC. Un nuovo set-up per le misure della sezione d’urto di fusione, appositamente progettato per fasci a bassa intensità forniti da SPES, è stato sviluppato presso i LNL. Questo nuovo set-up prevede l’utilizzo della FastIC progettata per resistere ad alti rate di conteggio per lo studio di processi di fusione con fasci esotici con intensità dell’ordine dei 10^5 pps. Il readout della FastIC è stato ottimizzato ed approfonditi test, eseguiti con fasci di ioni stabili, hanno dimostrato la sua capacità di operare fino a rate di 140 kHz, rispetto ai pochi kHz della precedente camera IC. L’alto rate di conteggio insieme al più ampio angolo solido consentiranno di rilevare i residui di evaporazione di fusione con un'efficienza vicina al 100%. La nuova FastIC è stata utilizzata durante l’esperimento di fusione sotto barriera dei due sistemi 36S+50Ti e 36S+51V. L’esperimento era finalizzato allo studio dei possibili effetti dello spin non nullo dello stato fondamentale del 51V, sulla funzione di eccitazione sotto barriera e sulla forma della distribuzione di barriere. La sezione d’urto di fusione è stata misurata fino a 20 μb e le funzioni di eccitazioni dei due sistemi mostrano andamenti simili. Un'analisi a canali accoppiati è stata eseguita al fine di evidenziare le differenze tra i due sistemi. In particolare, è stato utilizzato il codice CCFULL appositamente modificato per trattare il nucleo dispari 51V. Le funzioni di eccitazione sperimentali e le distribuzioni di barriera estratte sono state confrontate con le previsioni teoriche che suggeriscono una piccola differenza tra i due sistemi ad energie sopra barriera. Questo potrebbe essere osservato sperimentalmente mediante misure di diffusione quasi-elastica ad angoli all’indietro rispetto alla direzione del fascio.

Thesis (Ph. D., Education)--University of Idaho, October 2007.
Major professor: Martha C. Yopp. Includes bibliographical references (leaves 237-250). Also available online (PDF file) by subscription or by purchasing the individual file.

Lors d’un incendie en tunnel, la perte de visibilité due à la densité optique des fumées et leurs problèmes de toxicité sont considérés comme les risques principaux auxquels les usagers sont exposés. Pour cela, le contrôle de la fumée est souvent la partie la plus importante de la planification d’urgence. Les systèmes de ventilation sont l’une des principales mesures de protection à adopter pour empêcher la fumée de se répandre. Cependant, la propagation de la fumée est un phénomène très complexe et il est donc parfois difficile à contrôler. Cette complexité exige de meilleurs outils de sécurité pour améliorer l’efficacité des systèmes de ventilation et assurer ainsi la sécurité des personnes en cas d’incendie, ce qui constitue l’objectif principal de nos travaux de recherche. Dans cette thèse, l’étude des incendies dans les tunnels routiers équipés de systèmes de désenfumage longitudinaux et transversaux a été réalisée expérimentalement et numériquement. Les expériences ont été menées dans la maquette située au LMFA et les simulations numériques ont été réalisées en utilisant le code de calcul FDS (Fire Dynamics Simulator) avec l’approche de simulation des grandes échelles LES (Large Eddy Simulation). Le foyer est modélisé par le rejet d’un mélange d’air et d’hélium dans de d’air frais. Avec ce type de simulation d’incendie, les pertes de chaleur par rayonnement et par conduction à travers les parois du tunnel ne sont pas prises en compte, mais le modèle peut néanmoins fournir des informations sur la phénoménologie et les champs de données pouvant être comparés à des incendies réels. Dans une première partie, des mesures de champ de vitesse ont été effectuées à l’aide de la technique de vélocimétrie par images de particules PIV pour étudier la dynamique des rejets flottants dans des tunnels à ventilation longitudinale. L’objectif est d’évaluer les effets non Boussinesq (liés aux grandes différences de densité entre le rejet flottant et l’air ambiant) sur la dynamique des rejets "forcés" et "paresseux", dominés respectivement par le flux de quantité de mouvement et le flux de flottabilité. Ensuite, l'effet de barrières solides (connues sous le nom "d'écrans de cantonnement" et placées au plafond du tunnel) sur la propagation des fumées d’incendie dans des tunnels à ventilation longitudinale est étudié. Deux types d'obstacles ont été examinés: des "petites barrières", conçues pour être fixées le long du plafond du tunnel, et des "grandes barrières", conçues pour être mobiles et déployées uniquement en cas d’incendie. Pour ce dernier type, seulement une seule barrière est placée au plafond du tunnel. Les expériences ont été réalisées avec et sans les effets de blocage des véhicules, qui sont modélisés par des blocs cubiques de différentes tailles. Les résultats ont montré que les barrières peuvent contrôler efficacement la propagation des fumées, même à basses vitesses de ventilation. Le taux de réduction de la vitesse critique (définie comme la vitesse de ventilation minimale à partir de laquelle toutes les fumées sont repoussées en aval du feu, dans le même sens que le flux de ventilation) dépend du taux de blocage créé par les obstacles (barrières, blocs ou les deux) situés juste en amont de la source. Les pertes de charge induites par ces barriers ont été aussi évaluées. Les résultats finals ont montré que les grandes barrières sont plus efficaces que les petites barrières car elles réduisent considérablement la vitesse critique et induisent moins de perte de charge dans les tunnels encombrés. Dans une deuxième partie, à l'aide d'un système de ventilation transversale, les conditions de confinement des fumées entre deux trappes d’extraction situées de part et d'autre de la source sont étudiées. Les effets de la forme et de la position des trappes (y compris le cas particulier des trappes de pleine largeur) sur les performances du système de ventilation transversale ont été évalués. [...]
In this thesis, fires in road tunnels with longitudinal and transverse ventilation systems are investigated numerically and experimentally. The fire smoke is simulated as a buoyant plume obtained by injecting a mixture of air and helium into ambient air. With this simplified representation, the radiation and the heat losses at the walls are not taken into account, but the model can nevertheless provide relevant information on phenomenology and data fields that can be compared to real fires. The study aims to meet various objectives, in particular increasing the efficiency of the mechanical ventilation systems and improving the safety of tunnels users in the event of fires. In the first part, experiments are conducted to measure, using Particle Image Velocimetry (PIV) system, the velocity fields induced by turbulent buoyant plumes released within a longitudinally ventilated tunnel. The aim is to study the non-Boussinesq effects (i.e. effects related to large density differences between the buoyant plume and the ambient air) on the dynamics of the momentum-driven releases and buoyancy-driven releases. Then, the effect of solid barriers, placed at the tunnel ceiling, on the propagation of smoke in fire events within longitudinally ventilated tunnels is studied. Two types of barrier are considered: "small barriers" designed to be fixed in place and "large barriers" designed to be mobile in real tunnels. Experiments are carried out with and without vehicular blockage, which are modelled by blocks of different sizes and placed upstream of the source. It is found that the presence of barriers and/or blocks reduces the critical velocity, which is defined as the minimum ventilation velocity required to ensure that all the smoke remains downstream of the source, in the same direction as the ventilation flow. The reduction rate of the latter depends on the blocking rate created by the obstacles (barriers, blocks or both) located just upstream of the source. Subsequently, the effect of blockages on pressure losses inside the tunnel is investigated. It is shown that the large barriers are more effective than small ones because they reduce the critical velocity and induce less pressure losses in congested tunnels. In the second part, using a transverse ventilation system, the conditions of confinement of the smoke flow between two exhaust vents located on either side of a buoyant source are investigated. The effect of the shape and the position (with respect to the tunnel axis) of the dampers, including the specific case of full-width dampers, on the performance of the transverse ventilation system is evaluated. The extent of the backflow length beyond the extraction dampers, the confinement velocity and the stability of the smoke stratification are studied. Results show that the greater the proportion of the tunnel width the vent covers and the closer to the centre of the tunnel the vent is placed, the more efficient the ventilation system at confining the smoke to the extraction zone and ensuring the stability of the smoke stratification. The effect of solid barriers placed at the tunnel ceiling is also evaluated with transverse ventilation and it’s found that large barriers can improve the efficiency of vents that do not cover the full width of the tunnel, by reducing the confinement velocity and enhancing the stability of the smoke stratification. In the last part, numerical simulations of fires in a tunnel with longitudinal and transverse ventilation are carried out using Fire Dynamics Simulator (FDS) software and Large Eddy Simulation (LES) approach. Several physical simulations are numerically reproduced to complete the interpretation of the experimental results. A good agreement is usually reached between the experimental and the numerical results. [...]

Thesis (Ph. D.)--University of California, Riverside, 2009.
Includes abstract. Available via ProQuest Digital Dissertations. Title from first page of PDF file (viewed March 23, 2010). Includes bibliographical references. Also issued in print.

Rare Physics event is playing a crucial role, not only in Fundamental Interaction Physics, but also in Astroparticle Physics and in Cosmology. These signals, if detected, would give an importatnt evidence of new Physics. The CUORE experiment (Cryogenic Underground Observatory for Rare Events) is a proposed tightly packed array of 988 TeO2 bolometers, each being a cube 125 cm3 on a side with a mass of 750 g. The array consists of 19 vertical towers, arranged in a compact cylindrical structure. Each tower will consist of 13 layers of 4 crystals. The design of the detector is optimized for ultralow-background searches. Neutrinoless double-beta decay (ββ0ν) is the main goal of CUORE. What is new is the fact that positive observation of neutrino oscillations gives new motivation for more sensitive searches. Neutrino oscillation experiments can only provide data on the mass differences of the neutrino mass-eigenstates. The absolute scale can only be obtained from direct mass measurements (β-decay end point measurements), or in the case of Majorana neutrinos, more sensitively by neutrinoless double-beta decay observation. ββ0ν is not the only exotic process which can be observed in the CUORE experiment. Other rare events, from cold dark matter, to rare nuclear decays and electron decay can in principle be studied with the CUORE experimental facility. I will discuss the last process in the 6th chapter. The topic which joins the exotic and rare processes discussed is the unwanted radioactive background which is inevitably present in the experimental measurements. CUORICINO, almost a single CUORE tower, was constructed as a smaller scale ex- periment and operated from december 2003 to June 2008. Besides being a sensitive experiment on 130Te double beta decay, CUORICINO is a conclusive test of CUORE. CUORICINO provided important results concerning both the technical performances of the bolometric tower (CUORE will be made of 19 such towers), the background level .In particular, one of the information gained is that the most probable candidates for the continuum background observed in the spectra, are the surface α contaminations of the copper mounting frame. Rare Physics event is playing a crucial role, not only in Fundamental Interaction Physics, but also in Astroparticle Physics and in Cosmology. These signals, if detected, would give an importatnt evidence of new Physics. The CUORE experiment (Cryogenic Underground Observatory for Rare Events) is a proposed tightly packed array of 988 TeO2 bolometers, each being a cube 125 cm3 on a side with a mass of 750 g. The array consists of 19 vertical towers, arranged in a compact cylindrical structure. Each tower will consist of 13 layers of 4 crystals. The design of the detector is optimized for ultralow-background searches. Neutrinoless double-beta decay (ββ0ν) is the main goal of CUORE. What is new is the fact that positive observation of neutrino oscillations gives new motivation for more sensitive searches. Neutrino oscillation experiments can only provide data on the mass differences of the neutrino mass-eigenstates. The absolute scale can only be obtained from direct mass measurements (β-decay end point measurements), or in the case of Majorana neutrinos, more sensitively by neutrinoless double-beta decay observation. ββ0ν is not the only exotic process which can be observed in the CUORE experiment. Other rare events, from cold dark matter, to rare nuclear decays and electron decay can in principle be studied with the CUORE experimental facility. I will discuss the last process in the 6th chapter. The topic which joins the exotic and rare processes discussed is the unwanted radioactive background which is inevitably present in the experimental measurements. CUORICINO, almost a single CUORE tower, was constructed as a smaller scale ex- periment and operated from december 2003 to June 2008. Besides being a sensitive experiment on 130Te double beta decay, CUORICINO is a conclusive test of CUORE. CUORICINO provided important results concerning both the technical performances of the bolometric tower (CUORE will be made of 19 such towers), the background level .In particular, one of the information gained is that the most probable candidates for the continuum background observed in the spectra, are the surface α contaminations of the copper mounting frame. Silicon Barrier Detectors (SBD) are a powerful instrument to study charged particle radiation (like α particles). During my PHD one of the activity I focused on was the optimization of the SBD used in the radioactivity laboratoty of the the University of Milano Bicocca A complete procedure for the calibration of these detectors was set- tled. In fact, one of the main problem to face with, (due also to the extremely low activity measured), is the discrimination of their intrinsic background level from that of the sample measured. The SBD are always operated in Ultra Low Background vacuum chambers. In the context of the discrimination of the background, evaluation of the muon and shower contribution to the acquired spectra were performed. The latter were done through a coincidence measurement between the SBD and a scintillator. The result of the measurements and of their ananlysis showed that the major contribution to the spurious counts comes from the showers. A dedicated acquisition was done for the detectors, with a module which lets to have event’s temporal imformation. To give limits on the surface activities of the samples the use of Monte Carlo (MC) simulation is mandatory in order to have an estimation of the efficiency of energy detection. The use of the MC simulation was optimized: different depht and profiles of contamination were studied and tested. This optimization allows to give limits on surface 232Th, 238U and 210Pb-Po activities which depend on the depht of contamination. The drastic reduction of the sensitivity achieved (from 10−5 to 10−7 and 10−8 Bq · cm2 fo the cleanest material measured) is due to the described optimiza- tion. Last, but non least, the SBD measurements played a crucial role in the material selection, depending on the radiopurity required, for the CUORE experiment. Concering the ββ0ν, a crucial role, in the theoretical interpretation of the experimental result, is played by the Nuclear Matrix Element (NME) used to transalte the observed rate (in the energy region where the signal is expected) in a sensitivity on the effective neutrino mass |mν|. I performed a study in order to compare and understand the different nuclear models used nowadays, and the respective Phase Space Factors (PSF) used. This study allows to compare, in a quantitative way, the different experiments on neutrinoless double beta decay. A database was realized in which all the inputs are collected, comments and references on NME and PSF are illustrated and the kind of short range correlation is used in the calculation of the matrix element. The database, with the information collected and properly organized, allows to evaluate the sensitivity on |mν| of all the experiments now at work, depending on the nuclear model used. The difficulties encountered in the comprehension of the nuclear models and in the PSF used are due to three main reasons. • the PSF shoul be in principle standard and unambiguous, not depending on the nuclear model, but just on the initial and final states JP . This is not what the study showed: the PSF, in the different formulation, show discrepancies of a factor 5 or 6. • the nuclear models assume different approaches to the process and should lead to different results. Two models, i.e., the Shell Model and the IBM (Interactive Boson Model) have a similar approach, but they differ in handling the states which are ’far from closed shells’, so in the handling of the nuclear deformations. The QRPA, (in the version pnQRPA an rQRPA, Quasi Random Phase Approximation), have a different approach to the previous models, because it introduces the concept of quasiparticle, which are states built with a ’mixing’ of creation and annihilation operators (a theory very similar to BCS for the superconductivity) and it leads to a correlation between particles and holes and not just between particles (gph and not only gpp pairing). • the SRC (shot range correlation) used should be univocal, but this is not the case. The theoreticians don’t give a clear choice of the proper SRC to be used. Finally I performed a study on the electron decay, in the channel e− ← γ + ν, using CUORICINO data. Moreover I performed a calculation of the cross section for the process, assuming a massless neutrino in the first step and a massive neutrino in the second step. The study of the channel implies to evaluate the signature of the decay, which depends on the material and atomic shell from which the electron disappears. In fact the visible energy changes if the decay happens in the active volume of the detector or in the surroinding materials: Ev = (mec2−Eb) 2 + EX = (mec2+Eb) 2 where me is the electron mass, Eb is the binding energy, EX is the X-ray energy following the decay. The last term is included only if the decay happens inside the active volume of the detectors. Thus, there are several signatures which can be discriminated from the background only if the detector resolution is excellent. Moreover the doppler broadening of the lines, due to the orbital motion of the electron in the shell, must be considered. I thus studied the different signatures in several materials, (potential emitters). In the analysis I included the efficiences for the signatures, using Monte Carlo simulations, expressely conformed to experimental set-up and charachteristics (such as real thresholds, active channels). The correction to the efficiencies, i.e. the loss of ’good events’, due to the analysis cuts, was evaluated. All the analysis done led to a promising result for this decay, in competition with the current limits given from other collaborations. The cross section calculation allowed to give an estimation of the CNC parameter, using as inputs the available experimental data.

Thesis (Ph.D.)--University of Delaware, 2008.
Principal faculty advisors: Valeria Gabriela Stoleru, Dept. of Materials Science & Engineering; and S. Ismat Shah, Dept. of Materials Science. Includes bibliographical references.

Thesis (Ph. D.)--University of Delaware, 2006.
Principal faculty advisor: Andrew V. Teplyakov, Dept. of Chemistry & Biochemistry and Raul F. Lobo, Dept. of Chemical Engineering. Includes bibliographical references.

Humans do not live by bread alone. Physically we are puny creatures with limited prowess, but with unlimited dreams. In the last few decades humankind reached the Moon (1969) and built airports over the sea (1994), but 925 million people are still under- or malnourished (2010). To follow his dream to ensure every human being the same adequate quality of life, humankind needs energy. The long-term world energy scenarios (50-80 years) foresee the need for reliable, sustainable and environmental friendly sources of energy. Thermonuclear fusion is one of the main actors in the energetic basket, it offers the possibility to produce large supplies of energy at relatively low costs reducing the impact on the environment. In fact, thermonuclear fusion represents a promising chance to generate energy without the emission of carbon dioxide and the production of long living radioactive wastes. Moreover, the raw materials used as fuel in the fusion reactions, deuterium and tritium, are easily available on Earth. This chance motivates the efforts on the controlled thermonuclear fusion research. Anyway, the development of nuclear fusion as an energy source is one of the most complex scientific and technical tasks ever undertaken for non-military purposes. The nuclear fusion obtained by magnetic confinement of plasma emerged in the latest years as the most promising concept to menage the power produced by fusion reactions. The studies developed in that direction, since the fifties, yielded more and more encouraging results and important breakthroughs both in physics and technology and inspired the ITER project. This experimental reactor could give, in the next few decades, the definitive answers to many questions on the scientific and technological feasibility of a fusion reactor. One of the major concerns in magnetic confinement fusion research is the quest for the best plasma performance, which is intimately linked to two main issues: plasma confinement and boundary conditions. Both, incidentally, are connected to plasma stability. The link between confinement and boundary conditions is very strong and found many evidences. For example in the tokamak (the magnetic confinement configuration main line) the quest for a mild plasma-wall interaction a controlled recycling led to the discovery of an ameliorated operating mode with high performance. As a matter of fact, H-mode was discovered in ASDEX the first diverted device. In RFPs (an alternative magnetic confinement configuration) a spontaneous transition to an ameliorated plasma state, the QSH state, is due to a reduced chaos obtained with an accurate control of the magnetic boundary conditions. In turn, the access to the QSH state led to a favorable edge topology characterized by better boundary conditions. The onset of the QSH state induces an edge helical ripple which reduce the plasma wall interaction. My research activity, reported in this thesis work, focused on the accessibility conditions and characterization of improved confinement regimes in TCV tokamak and RFX-mod RFP devices. In RFX-mod my research activity focused on the study and the characterization of electron temperature profiles. Temperature is one of the key parameters that qualifies fusion plasma performance and, in RFX-mod plasmas, it is mainly determined by three quantities: plasma current, electron density and plasma magnetic state. Through a large statistical analysis the temperature profile variations were investigated and related to the main macroscopic and operational plasma parameters. This analysis resulted in scaling laws for central temperature, external temperature and temperature gradient. Some further analysis was dedicated to a distinctive feature: the appearance of transport and thermal barriers which result in better plasma performance. The formation of an Internal Transport Barrier (eITB) is triggered by the growth of a dominant MHD tearing mode which, in turn, leads to a reduced magnetic chaos in the plasma core. Starting from previous analysis, these eITBs were investigated and their influence of the whole temperature profile addressed. Besides the established phenomena related to eITBs, the occasional appearance of extremely high gradients in the external region of the plasma column was observed. Some general observations and a first speculation on the physical mechanism leading to their formation will be presented. The work ends up in a wide and general picture which tries to clear up the physics governing the temperature profile modifications and proposes possible operations to trigger them. Present day tokamaks high performance scenarios rely on the possibility to access the high confinement mode (H-mode). Transition from the standard confinement mode (L-mode) to the H-mode is typically achieved when the external input power exceeds a threshold. This power threshold is found to strongly depend on plasma density, toroidal magnetic field and plasma size, but many experiments have shown this power threshold to also depend on plasma shape and configuration geometry. My activity at TCV aimed at the study of such dependence, in particular the influence of X-point location on H-mode power threshold was investigated. During a two months stay in 2011, a series of experiments was dedicated to such a study. Significant variations in the power threshold due to a reduction of the X-point height has been documented, in agreement with the scaling observed in other machines. Moreover, the well-established non-monotonic density dependence of the H-mode power threshold has been measured and recorded. In this thesis work the analysis procedure followed to the TCV experimental campaign is reported.
L’ uomo non vive di solo pane. Fisicamente siamo creature minute con possibilitá ridotte, ma i nostri sogni non conoscono confini. Negli ultimi decenni l’umanitá è sbarcata sulla Luna (1969) e ha costruito aeroporti sul mare (1994), ma 925 milioni di persone sono soffrono ancora la fame (2010). Per inseguire il sogno di assicurare ad ogni essere umano una qualitá di vita decorosa, l’umanitá ha bisogno di energia. Le prospettive energetiche a lungo termine (50-80 anni) prevedono la necessitá di sorgenti di energia affidabili, sostenibili ed eco-compatibili. La fusione termonucleare è una delle possibilitá piú promettenti all’interno del paniere energetico, infatti offre la possibilitá di produrre energia in grandi quantitá a costi relativamente bassi e con un ridotto impatto ambientale. La fusione termonucleare potrebbe diventare una fonte energetica senza emissioni di anidride carbonica e con una minima produzione di scorie radioattive a lunga vita media. Inoltre, le materie prime utilizzate come combustibile nelle reazioni di fusione, deuterio e trizio, sono ampiamente disponibili sulla Terra. Ecco i validi motivi per gli sforzi dedicati allo studio della fusione termonucleare controllata. Ma, lo sviluppo della fusione nucleare come fonte di energia è una delle sfide piú complesse dal punto di vista tecnico-scientifico mai intraprese per scopi non militari. La fusione nucleare a confinamento magnetico del plasma é emersa negli ultimi anni come l’idea piú promettente per gestire l’energia prodotta da questa fonte di energia. Gli studi sviluppati in questa direzione, dagli anni Cinquanta, hanno dato risultati sempre piú incoraggianti, hanno portato ad importanti innovazioni sia nel campo della fisica che della tecnologia e hanno ispirato il progetto ITER. Questo reattore sperimentale potrebbe dare, nei prossimi decenni, le risposte definitive a molte domande sulla fattibilitá scientifica e tecnologica di un reattore a fusione. Uno dei principali interessi nel campo della ricerca sulla fusione a confinamento magnetico è la ricerca delle migliori prestazioni di plasma. Queste sono intimamente legate a due aspetti: confinamento del plasma e le condizioni alla parete. Entrambi, per inciso, sono collegati alla stabilitá del plasma. Il legame tra il confinamento e le condizioni alla parete è stretto e ben documentato. Ad esempio nel tokamak (la principale configurazione a confinamento magnetico) la ricerca di una ridotta interazione plasma-parete e di un riciclaggio controllato ha portato alla scoperta di una modalitá di funzionamento migliorata caratterizzata da alte prestazioni. Infatti, il modo H è stato scoperto ad ASDEX la prima macchina con divertore. Nei RFP (una configurazione alternativa) una transizione spontanea verso uno stato di plasma migliorat, lo stato QSH, legata ad un ridotto caos è stata ottenuta ottenuta con un accurato controllo delle condizioni magnetiche a bordo plasma. A sua volta, l’accesso alla QSH ha portato ad una topologia magnetica favorevole caratterizzata da una migliore condizione a bordo plasma. L’insorgere della QSH induce un ripple elicoidale al bordo che riduce l’interazione plasma-parete. La mia attivitá di ricerca, riportata in questo lavoro di tesi, si è concentrata sulle condizioni di accessibilitá e la caratterizzazione dei regimi di confinamento migliorato nei due sperimenti TCV (di tipo tokamak) ed RFX-mod (di tipo RFP). In RFX-mod la mia attivitá si è concentrata sullo studio e la caratterizzazione del profilo di temperatura elettronica. La temperatura è uno dei parametri fondamentali per qualificare le prestazioni dei plasmi da fusione e, in RFX-mod, è determinata principalmente da tre parametri: corrente di plasma, densitá elettronica e stato magnetico. Attraverso un’analisi statistica ad ampio spettro, le variazioni del profilo di temperatura sono state analizzate e poste in relazione con le principali grandezze macroscopiche ed i parametri operativi della macchina. L’andamento gnerale di temperatura centrale, temperatura esterna e gradiente di temperatura è stato rappresentato attraverso delle leggi di scala. Alcune ulteriori analisi sono state dedicate ad un fenomeno particolare: la comparsa di barriere di trasporto termico che determinano migliori prestazioni di plasma. La formazione di una barriera di trasporto interna (eITB) è innescata dalla crescita di un modo tearing dominante che, a sua volta, porta ad una riduzione del caos magnetico nel centro del plasma. Basandosi su lavori precedenti, le eITB sono state analizzate e la loro influenza sull’intero profilo di temperatura è stata valutata. Oltre ai consolidati fenomeni legati alle eITB, è stata osservata l’occasionale comparsa di gradienti molto elevati nella regione esterna della colonna di plasma. Alcune osservazioni di carattere generale e una prima speculazione sul meccanismo fisico che porta alla loro formazione saranno presentati. Il lavoro termina con un quadro ampio e generale che cerca di valutare la fisica che disciplina le variazioni del profilo di temperatura e propone alcune tecniche operative per il loro controllo. Negli odierni tokamak gli scenari ad alte prestazioni si basano sulla possibilitá di accedere ad uno stato ad alto confinamento (modo H). La transizione dallo stato di confinamento standard (modo L) al modo H si ottiene tipicamente quando la potenza esterna iniettata nel plasma supera una soglia. Questa soglia di potenza dipende fortemente dalla densitá del plasma, dal campo magnetico toroidale e dalle dimensioni del plasma, ma in molte macchine si è dimostrato come questa soglia dipenda anche dalla forma del plasma e dalla geometria della configurazione. La mia attivitá a TCV è stata dedicata allo studio di queste dipendenze, in particolare nell’analisi dell’influenza della posizione del punto a X. In due mesi di permanenza a Losanna nel 2011, ho partecipato ad una serie di esperimenti dedicati a tale argomento. Si sono documentate variazioni significative della soglia di potenza riducendo l’altezza del punto a X, in accordo con quanto giá osservato in altre macchine. Inoltre, la dipendenza non monotona di tale soglia dalla densità stata misurata e verificata. In questo lavoro di tesi si sono discussi le procedure di analisi seguite alla campagna spetimentale di TCV ed i conseguenti risultati.

The study of nonlinear dynamical systems in the presence of both Gaussian and non-Gaussian noise sources is the topic of this research work. In particular, after shortly present new theoretical results for statistical characteristics in the framework of Markovian theory, we analyse four different physical systems in the presence of Levy noise source. (a) The residence time problem of a particle subject to a non-Gaussian noise source in arbitrary potential profile was analyzed and the exact analytical results for the statistical characteristics of the residence time for anomalous diffusion in the form of Levy flights in fully unstable potential profile was obtained. Noise enhanced stability phenomenon was found in the system investigated. (b) The correlation time of the particle coordinate as a function of the height of potential barrier, the position of potential wells and noise intensity was investigated in the case of confined steady-state Levy flights with Levy index alpha=1, that is Cauchy noise, in the symmetric bistable quartic potential. (c) The stationary spectral characteristics of superdiffusion of Levy flights in one-dimensional confinement potential profiles were investigated both theoretically and numerically. Specifically, for Cauchy stable noise we calculated the steady-state probability density function for an infinitely deep rectangular potential well and for a symmetric steep potential well. (d) For two-dimensional diffusion the general Kolmogorov equation for the joint probability density function of particle coordinates was obtained by functional methods directly from two Langevin equations with statistically independent non-Gaussian noise sources. We compared the properties of Brownian diffusion and Levy flights in parabolic potential with radial symmetry. Afterwards, we analyzed the nonlinear relaxation in the presence of Gaussian noise for the stochastic switching dynamics of the memristors. We have studied three different models. (a) We started from consideration of the simplest model of resistive switching. (b) Further, the charge-controlled and the current-controlled ideal Chua memristors with external Gaussian noise were investigated. For both cases we have obtained exact analytical expressions for the probability density function of the charge flowing through the memristor and of the memristance. (c) Moreover, we proposed a stochastic macroscopic model of a memristor, based on a generalization of known approaches and experimental results. Steady-state concentration of defects for different boundary conditions was found. Also we analysed how the concentration of defects is changed with time under arbitrary values of external voltage, noise intensity, effective diffusion coefficient and other parameters. An examination of the results was performed, the possible implications of this work and the future development of this study were outlined.

Rapidly changing consumer preferences and technological innovation demands enhanced manufacturing flexibility not only for productivity enhancement but for the survival of manufacturing company. Higher manufacturing flexibility offers the company to feed their customers with the variety of product according to their demand. Flexibility in manufacturing system helps to accommodate dynamic changes and helps the company to sustain in the competitive market. This research focuses on prioritization of considered barriers, which are faced during implementation of the Flexible manufacturing system in Indian Automobile Industry. To achieve the objective, a set of significant barriers were identified based on literature review and discussion with field experts, chosen from automobile industry located at National capital region (NCR) of India. Fuzzy TOPSIS methodology is used to priorities these barriers. Analysis of the findings reveals that top four prioritized factors High initial capital cost, skilled workers, Resource allocation problem, and Floor layout problem are the four most important among all 17 factors. These significant factors to be considered for the effective implementation of flexible manufacturing systems in context to Indian automobile Industry.

Thesis (M.A.)--Northern Kentucky University, 2008.
Made available through ProQuest. Publication number: AAT 1456468. ProQuest document ID: 1605146081. Includes bibliographical references (p. 45-48)

Thesis (Ph.D.)--University of Nebraska-Lincoln, 2009.
Title from title screen (site viewed January 5, 2010). PDF text: vi, 179 p. : ill. ; 770 K. UMI publication number: AAT 3360088. Includes bibliographical references. Also available in microfilm and microfiche formats.

Thesis (M.S.)--State University of New York at Buffalo, 2008.
Title from PDF title page (viewed on Jan. 20, 2009) Available through UMI ProQuest Digital Dissertations. Thesis adviser: Dargush, Gary F. Includes bibliographical references.

Thesis (M.S.)--State University of New York at Buffalo, 2008.
Title from PDF title page (viewed on Dec. 4, 2008) Available through UMI ProQuest Digital Dissertations. Thesis adviser: Wactawski-Wende, Jean, Tumiel-Berhalter, Laurene Includes bibliographical references.

Thesis (M.A.)--Northern Kentucky University, 2008.
Made available through ProQuest. Publication number: AAT 1450504. ProQuest document ID: 1490075971. Includes bibliographical references (p. 54-60)

Thesis (Ph.D.)--State University of New York at Buffalo, 2007.
Title from PDF title page (viewed on Oct. 14, 2008) Available through UMI ProQuest Digital Dissertations. Thesis adviser: Hoot, James Includes bibliographical references.

Thesis (M.A.)--State University of New York at Buffalo, 2008.
Title from PDF title page (viewed on Nov. 13, 2008) Available through UMI ProQuest Digital Dissertations. Thesis adviser: Rintamaki, Lance S. Includes bibliographical references.