Dissertations / Theses on the topic 'Confined space'

The extent of work related fatal accidents has been analysed statistically by agencies throughout the world. As a result of this analysis there is a wealth of information available categorised by industry types, sub-industry, occupation, sex, age, nature of occurrence, bodily location, agency of occurrence and mechanism of injury. It is however extremely difficult to identify information pertaining to confined space fatalities such as contributory factors, mechanisms of injury and other data of an epidemiological nature.

The extent of work related fatal accidents has been analysed statistically by agencies throughout the world. As a result of this analysis there is a wealth of information available categorised by industry types, sub-industry, occupation, sex, age, nature of occurrence, bodily location, agency of occurrence and mechanism of injury. It is however extremely difficult to identify information pertaining to confined space fatalities such as contributory factors, mechanisms of injury and other data of an epidemiological nature.

Despite the plethora of information regarding cellular crowding and its importance on modulating protein function the effects of confinement on biological molecules are often overlooked when investigating their physiological function. Recently however, the encapsulation of biomolecules in solid state matrices (NafionTM, sol-gels, zirconium phosphate,etc.) has increased in importance as a method for examining protein conformation and dynamics in confined space as well as novel applications in biotechnology. Biotechnological applications include, but are not limited to, bioremediation, biosensors, biocatalysts, etc. In order to better utilize solid state materials as substrates for biological molecules an understanding of the effects of encapsulation on the detailed dynamics associated with physiological function is required as well as a complete characterization of the physical properties associated with the space in which the biological molecule is to be confined. The focus of this research is to probe the effects of confinement on the thermodynamics of ligand photo-release/rebinding to the prototypical heme protein, myoglobin, encapsulated within sol-gel glasses utilizing photoacoustic calorimetry (PAC) and photothermal beam deflection (PBD). Optical spectroscopies (including optical absorption and fluorescence) have also been employed to characterize the molecular environments of materials including Zr-phosphate and metal organic polyhedral (MOPs), thought to be good candidates for novel bio-hybrid materials. The assembly mechanisms associated with MOPs were also examined in order to develop a foundation through which new, bio-compatible MOPs can be designed. Overall the results presented here represent a technological breakthrough in the application of fast calorimetry to the study of proteins in confined space. This will allow for the first time the acquisition of detailed thermodynamic maps associated with the well-choreographed biomolecular dynamics in confined environments.

Supramolecular structures have emerged as a promising enzyme mimetic. In this study we focused on the resorcinarene hexamer which is a self assembled capsule that have been studied intensively due to it’s ready availability. The hexameric capsule shows some catalytic features reminiscent of natural enzymes include; substrate selectivity , stabilization of transition state and intermediate through secondary interactions, an inherent Bronsted acidity and it’s ability to act as a hydrogen bond catalyst. Inside the cavity of the capsule reagents are confined in a restricted space in close proximity, such that they react faster . Here in, It was shown how the catalytic activity of the capsule can be modulated in the presence of competitive alkyl ammonium guests in the profile of conversion of tri alkyl phosphite substrate to it’s corresponding di alkyl phosphite product. The profile of the reaction was monitored using GC and NMR spectroscopy.

In my thesis I have focused on examining the structural and dynamic properties of (5CB)„ clusters. Under normal circumstances, it appears that a bulk sample of 4-n-pentyl-4'- cyanobiphenyl changes dramatically its properties at the temperature about 310 K. Above this temperature pure 5CB sample occurs in isotropic phase and loses liquid crystalline properties. In this study I was able to show that placing 5CB molecules near the carbon nanostructures such as nanotube, graphite, or graphene increases the level of molecular order. Moreover, the second rank order parameter P2 decreases slowly with an increasing of temperature. Therefore, the nematic phase of 5CB cluster may persist in wider temperature range, which is desirable in certain technical applications. Another important and interesting observation is that embedding 5CB mesogens inside SWCNT enhance the process of diffusion along director. The average value of the second rank order parameter is higher than in 5CB sample adsorbed on the outer surface of nanotube. Similar but weaker effect is observed in (5CB)n cluster confined between graphite or graphene sheets. It also appears that chirality of SWCNT has impact on the dynamics of liquid crystal layer located near carbon surface. Some o f the presented results seem to be of interest both from scientific point of view and also because of their potential applications in nanoelectronic devices, chemical biosensors and liquid crystal displays.

In this work, an in-depth analysis of crystalline characteristics has been performed for a unique set of strictly monodisperse poly-ε-caprolactone (PCL) oligomers. The molecules have different sets of end groups with various degrees of bulkiness and hydrogen bonding potential, affecting their aptitude to pack in ordered crystal structures. The oligomers also have different numbers of repeating units (n = 2-64), affecting the degree to which end groups influence overall molecular characteristics. The presence of bulky end groups leads to an innate confinement effect on crystallisation which in turn makes it possible to utilize the set of PCL oligomers to study confined space crystallisation. Confined space crystallisation is explored as a route to gain further understanding about the early metastable phases in crystal formation.

 

The monodisperse nature of the samples made it possible to collect very precise small-angle and wide-angle X-ray scattering data (SAXS and WAXS) as well as calorimetric data. Computer modeling studies were performed to support experimental findings. It was shown that end groups strongly affected crystallisation features for the shorter oligomers (n ≤ 8) but to a lesser extend for the longer oligomers (n ≥ 16). The presence of a bulky end group at one end of an oligomer could inhibit the formation of hydrogen bonds on the other end. Short oligomers (n = 8) with OH-end groups exhibited novel packing characteristics. At one isothermal crystallisation temperature the molecules exhibited not only lamellar ordering but also an additional, likely rectangular or slanted, ordering. The sample was packed in a unique structure with molecular chains lying parallel but not aligned head to head with each other. At a higher crystallisation temperature the molecules packed in a double layered structure and at an even higher temperature in a typical non-folded but tilted single-molecular layer pattern.

 

Unit cell determination was performed for a short oligomer with two bulky end groups, showing the existence of a tetragonal unit cell with different dimensions than the orthorhombic unit cells previously reported for linear PCL without end groups. To gain greater insight into the earliest stages of molecular packing, in situ WAXS measurements were performed using a synchrotron radiation beam and measuring data each 12 s whilst very slowly going from melt to isothermal crystallisation. It was shown that the crystal unit cell was distorted during the first minutes of slow crystallisation, which might either represent a metastable phase or else a highly distorted orthorhombic phase.

La presente Tesis Doctoral consiste en la formación y desarrollo de hidratos de metano en el espacio confinado de nanomateriales porosos (carbones y MOFs) para ser utilizados como sistemas eficientes de almacenamiento de metano (gas natural). La tesis está dividida en dos secciones. En la primera sección, se explica el estado actual del arte y la necesidad de buscar alternativas a los sistemas de almacenamiento de metano por compresión y licuefacción. Además, se explican los materiales evaluados, así como las diferentes técnicas experimentales utilizadas para su caracterización, con especial énfasis en la caracterización de los hidratos de metano. En la segunda sección de la tesis, se recogen los resultados más relevantes en 5 capítulos. En el primer capítulo se estudian los procesos de congelación y fusión de agua en un carbón activado y el efecto que produce la aplicación de presión de metano en materiales semejantes en composición, pero diferente tamaño de poro. En el tercer capítulo se evalúa la formación de hidratos en un carbón activado con aditivos para promover cinética y termodinámicamente el crecimiento del mismos. En el cuarto capítulo se utiliza se utiliza agua marina y se compara sus efectos en los hidratos con respecto a agua destilada. En el quinto capítulo se seleccionan dos MOFs altamente porosos como alternativas a carbones para crecer cristales de hidratos.

Hypoxic ground gas is rarely reported in London despite its frequent occurrence in the Upnor Formation and the serious health and safety implications for underground working. The death of two engineers by asphyxiation and recent interception of pressurised hypoxic gas by two ground investigation boreholes highlight the urgent need for research into this hazard which until now has been extremely limited. Glauconite is legally and widely assumed to cause the oxygen loss in confined spaces but this research proves it incapable of doing so. Visual inspection and laboratory analysis, using optical and infrared spectroscopy, scanning electron microscopy and X-ray diffraction techniques confirm fresh glauconite within highly oxidised soil samples throughout the lower Lambeth Group and Thanet Sand Formation. The low concentration of pyrite and organic materials eliminates these as alternative causes. A poorly known but common bright blue-green mineral, green rust, is instead shown to be a very potent and plausible reducing agent. However, laboratory analysis under anoxic conditions has yet to prove its existence in the Upnor Formation, largely because of its extremely rapid oxidation, although the results are consistent with its presence in fresh samples. Significant preservation techniques were implemented to prevent oxidation of soil samples prior to laboratory analysis and improvements identified for future research. The presence of green rust during underground construction within the Upnor Formation will have serious implications for the health and safety of personnel. Measurements of soil suction, using the filter paper technique, show that the air entry value of the Lower Mottled Beds is such that they will act as an impermeable barrier to upward migration of hypoxic gas, trapping it within the underlying Upnor Formation. Field tests indicate that the gas is formed during periods of dewatering and may be influenced by changes in barometric pressure.

As the world observes a new pandemic with COVID-19, it is clear that pathogens can spread rapidly and without recognition of borders. Outbreaks will continue to occur, and so the diseases’ transmission method must be thoroughly understood in order to minimize their impact. Some infections, such as influenza, tuberculosis and measles are known to be spread through droplets in the air. In a confined space the concentration can grow as more droplets are released. This study examined a simulated confined space modelled as a hospital waiting area, where people who could have underlying conditions congregate and mix with potentially infectious individuals. It further investigated the impact of the volume of the waiting area, the number of people in the room, the placement of them as well as their weight. The simulation is an agent-based model (ABM), a computational model with the purpose of analysing a system through the actions and cumulative consequences of autonomous agents. The presented ABM features embodied agents with differing body weights that can move, breathe and cough in a ventilated room. An investigation into current epidemiological models lead to the hypothesis that one may be implemented as a corresponding ABM, where it could possibly also be improved upon. In this paper, it is shown that all parameters of the Gammaitoni and Nucci model can be taken into account in an ABM via the MASON library. In addition, proof is produced to suggest that some flaws of the epidemiological model can be mended in the ABM. It is demonstrated that the constructed model can account for proximity between susceptible people and infectors, an expressed limitation of the original model.
När världen observerar en ny pandemi, COVID-19, är det tydligt att patogener kan spridas fort och utan hänsyn till landsgränser. Utbrott kommer att fortsätta ske och därför måste sjukdomarnas överföringsmetod förstås, så att deras påverkan kan minimeras. Det är känt att vissa infektioner, såsom influensa, tuberkulos och mässling kan spridas via droppkärnor i luften. I ett begränsat utrymme kan koncentrationen växa när fler droppar tillförs. Denna studie utvärderar ett simulerat begränsat utrymme modellerat som ett väntrum på ett sjukhus, där människor som kan ha underliggande sjukdomar samlas och beblandar sig med potentiellt smittsamma individer. Inverkan av volymen av väntrummet, antalet personer i rummet, var de var placerade i rummet samt deras vikt undersöktes också. Simuleringen är en agent-baserad modell (ABM), en beräkningsmodell med syftet att analysera ett system genom handlingarna och kumulativa konsekvenserna av självstyrande agenter. Personer med olika kroppsvikt som kan röra sig, andas och hosta i ett ventilerat rum simuleras i denna ABM. Efterforskning av aktuella epidemiologiska modeller leder till hypotesen att en sådan skulle kunna implementeras som en motsvarande ABM, där den möjligtvis också kan förbättras. I denna rapport kommer det att uppvisas att alla parametrar av Gammaitonioch Nucci-modellen kan tas hänsyn till i en ABM via MASON biblioteket. Därtill produceras bevis som pekar på att vissa brister i den epidemiologiska modellen kan hämmas i denna ABM. Det demonstreras att den konstruerade modellen kan beakta distansen mellan mottagliga personer och smittsamma, vilket är en känd begränsning i originalmodellen.

Research on workplace health and safety analyses the integration of work practices with safety, health and wealth of people at work. The aim of occupational safety is to realize a safe and health work environment, eliminating or reducing the risks for workers' safety and health. The objective of this thesis is the study, integration, development and application of innovative approaches and models for decision-making support in the context of occupational safety in industrial plants and logistics. Such methodologies are expected to lead practitioners and decision-makers, in particular safety professionals and companies, in the management of occupational safety. In particular, this research focuses on the integration and application of ergonomics principles to reduce biomechanical overload of manual work, and methodologies and solutions to improve safety of confined space work in industrial plants. The study of biomechanical overload due to manual handling of loads and awkward postures is the object of several researches and publications addressing the ergonomic risk assessment and the ergonomic approach to remove or reduce the risk of manual handling injuries and disorders. Furthermore, when awkward postures are assumed in high-risk workplaces as confined spaces, the overall risk of work is extremely high. Confined space work is a high-risk activity, posing a significant hazard for both workers and rescuers involved in the emergency response. The leading cause of accidents and fatalities in confined spaces is atmospheric condition (Sahli & Armstrong 1992, Harris et al. 2005, Flynn & Susi, 2010, Meeker, Susi & Flynn 2010, Ye 2011, Bellamy 2015). Further common causes are fire, explosion, ignition of flammable contaminants, spontaneous combustion and contact with temperature extremes. Besides, work activities in confined spaces (e.g., welding and maintenance tasks) frequently require awkward and static postures, at high temperatures. This thesis stresses the importance of implementing health and safety interventions at workplace. These interventions have impact not only on enterprise level but also on individual and social levels. Furthermore, protection of human life is a matter of human rights and human life has an invaluable value. In this thesis, the role of occupational safety and safety strategy as means for the improvement of workers and companies’ performances clearly emerges. Two parallel research fields on occupational safety are investigated: ergonomics and confined spaces. Selected data are introduced related to occupational accidents and diseases due to biomechanical overload and work in confined spaces. The literature survey on controls for risk elimination and reduction shows that technology for safety is available. Nevertheless, injuries and accidents still occur, i.e. safety is frequently considered an expensive investment and a compliance obligation. Specifically, administrative and engineering controls for risk elimination and reduction are introduced for each research field. Administrative controls include work procedures and mathematical models for the design of safe work processes. Such control methods reduce the workers' exposure to occupational risk factors. The ergonomic analysis of manual handling activities drives the modelling by multi-objective optimisation problems in the design of administrative controls for the ergonomic risk reduction in different industries. Administrative controls for risks in confined spaces include work procedures, a multi-criteria decision tool and the analysis of the requirements of Internet of Things (IOT) technologies for reducing the risk of confined space work. The introduction of automation to replace manual work and engineering controls for confined space work are analysed for the risk elimination. Results show that the integration of ergonomics and safety principles in the industrial processes plays a leading role in the successful implementation of the overall strategy. Technologies for safe confined space work and technical solutions assisting workers during manual material handling tasks have been the focus of the Solutions Database Project, funded by the Azienda Unità Sanitaria Locale of Bologna (AUSL), Italy. The study of such technological and technical solutions lead to the development of the Solutions Database, a free access database available online for researchers and practitioners (http://safetyengineering.din.unibo.it/en/banca-delle-soluzioni). The thesis ends with the recommendation that companies should integrate workplace health and safety principles to human resource management and work organisation. The management of health and safety issues should be considered to be crucial for workplace development, as a lever to increase performance and productivity. Finally, this research aims to support and reinforce the evolution of the concept of safety in industry, from ex post required obligation, to ex ante optimisation strategy.
L'attività di ricerca in materia di salute e sicurezza negli ambienti di lavoro analizza l'integrazione tra le attività lavorative e la sicurezza, la salute e il benessere dei lavoratori. Lo scopo di tale scienza è di realizzare un ambiente di lavoro sano e sicuro, eliminando o riducendo i rischi per la salute e la sicurezza dei lavoratori. L'obiettivo di questa tesi è lo studio, l'integrazione, lo sviluppo e l'applicazione di approcci innovativi e modelli di supporto alle decisioni in merito alla sicurezza occupazionale negli impianti industriali e nella logistica. Tali metodi vogliono essere una guida per chi mette in pratica i principi della sicurezza nei luoghi di lavoro, quali aziende e professionisti della sicurezza, e coloro che sono chiamati a prendere decisioni in merito alla gestione della sicurezza dei lavoratori. In particolare, questa ricerca si focalizza sull'integrazione e l'applicazione dei principi dell'ergonomia per la riduzione del sovraccarico biomeccanico dovuto alle attività manuali, e di metodi e soluzioni per migliorare la sicurezza del lavoro negli ambienti confinati presenti negli impianti industriali. Lo studio del sovraccarico biomeccanico dovuto alla movimentazione manuale dei carichi e alle posture incongrue è l'obiettivo di numerose ricerche e pubblicazioni in merito alla valutazione del rischio ergonomico e all'approccio ergonomico per la rimozione e la riduzione del rischio d'infortuni e malattie professionali legate alla movimentazione manuale dei carichi. Inoltre, quando le posture incongrue sono assunte all'interno di ambienti lavorativi ad alto rischio, quali gli ambienti confinati, il rischio complessivo del lavoro diventa molto elevato. Il lavoro all'interno degli ambienti confinati è un'attività a elevato rischio, che espone sia i lavoratori che i possibili soccorritori coinvolti nella risposta d'emergenza a un elevato pericolo. La causa principale degli infortuni e degli incidenti mortali all'interno degli ambienti confinati è la condizione atmosferica presente nell'ambiente. Altre cause frequenti sono il fuoco, esplosione, presenza di contaminanti infiammabili, combustione spontanea e contatto con temperature elevate. Inoltre, l'attività lavorativa negli ambienti confinati (es., saldatura e manutenzione) richiede spesso posture statiche ed incongrue, mantenute in presenza di elevate temperature. Questa tesi sottolinea l'importanza dell'attuazione tempestiva degli interventi per il miglioramento delle condizioni di salute e sicurezza sul posto di lavoro. Questi interventi hanno un impatto non solo a livello aziendale, ma anche a livello individuale e sociale. Inoltre, la protezione del lavoratore è questione di diritti umani, e la vita umana ha un valore inestimabile. In questa tesi, emerge chiaramente il ruolo della strategia di gestione della sicurezza sul lavoro come mezzo per il miglioramento dei lavoratori e delle prestazioni aziendali. Due ambiti di ricerca in materia di sicurezza sul lavoro sono approfonditi parallelamente: l'ergonomia delle posture, dei movimenti e delle postazioni di lavoro, e le attività negli ambienti confinati. Saranno mostrati dati numerici e casistiche relative agli infortuni e alle malattie dovute al sovraccarico biomeccanico e al lavoro negli ambienti confinati, in ambito industriale. L'analisi della letteratura sui metodi per l'eliminazione e la riduzione del rischio mostra la presenza di numerose tecnologie, ad oggi disponibili, per la sicurezza dei lavoratori rispetto a tali ambiti. Tuttavia, gli infortuni, gli incidenti e le malattie professionali sono ancora presenti, a dimostrazione del fatto che la sicurezza è spesso considerata un costoso investimento e un mero obbligo di conformità alla normativa cogente. In particolare, questo elaborato presenta diverse metodologie di tipo amministrativo e tecnico per l'eliminazione e la riduzione del rischio in ciascun ambito di ricerca indagato. I controlli amministrativi comprendono procedure e modelli matematici per la progettazione dei processi di lavoro in sicurezza. Tali metodi di controllo riducono l'esposizione dei lavoratori ai fattori di rischio. L'analisi ergonomica delle attività di movimentazione manuale guida la modellazione dei problemi di ottimizzazione multi-obiettivo nella progettazione dei controlli amministrativi per la riduzione del rischio ergonomico in diversi settori industriali. I controlli di tipo amministrativo per la riduzione dei rischi in ambienti confinati includono procedure di lavoro, metodologie decisionali multi-criterio e l'analisi dei requisiti dei sistemi basati sulle tecnologie dell'Internet delle cose (IOT) per ridurre il rischio del lavoro negli ambienti confinati. L'introduzione dell'automazione a sostituzione del lavoro manuale e le metodologie tecniche per il controllo del rischio durante il lavoro negli ambienti confinati vengono presentati come strumenti per l'eliminazione del rischio. I risultati mostrano come l'integrazione dei principi dell'ergonomia e della sicurezza nei processi industriali svolga un ruolo di primo piano per il successo dell'attuazione della complessiva strategia aziendale. La tesi termina con la raccomandazione che le aziende dovrebbero integrare i principi di salute e sicurezza sul posto di lavoro per la gestione delle risorse umane con la strategia organizzativa e produttiva aziendale. La gestione dei problemi e dei rischi per la salute e la sicurezza dei propri lavoratori dovrebbe essere considerata come cruciale per lo sviluppo e il miglioramento dell'ambiente di lavoro, nonché un efficace leva per aumentare le prestazioni e la produttività dell'azienda. Infine, questa ricerca sostiene e rafforza l'evoluzione del concetto di sicurezza nel settore industriale, da ex post obbligo di adempimento a una normativa cogente, a ex ante strategia di ottimizzazione.

Regarding the myriad disputed documents encountered within the science of forensic document examination, questioned handwriting is the most prevalent. This includes the simulation or alteration of and or additions to handwriting and signatures. The current study examined the changes that may occur in writing when given a limited amount of space. Several participants completed a survey wherein writing samples were taken under varying space allowances. These space restrictions were made under differing conditions such as boxed signatures, additions to prewritten material, and alterations to letters and numbers. The results of the study found characteristics of reflex of avoidance in the participants' handwriting. These characteristics included changes in height, width, and letter spacing in accordance to the amount of space provided. The examples of reflex of avoidance defined throughout this study may serve to assist forensic document examiners in the detection of alterations within questioned documents.

Ces travaux de thèse ont consisté en la conception, la préparation et l’utilisation de nouvelles cages hémicyptophanes en tant que ligands supramoléculaires pour la coordination de métaux en milieu confiné. En particulier, nous nous sommes intéressés au développement de nouvelles méthodes pour l’obtention (i) de complexes énantiopures présentant une hélicité controllée et (ii) de nouveaux catalyseurs confinés plus efficaces et sélectifs. La première partie de ce travail consiste en une étude bibliographique sur (i) la synthèse et les applications des hémicryptophanes en reconnaissance et catalyse et (ii) les examples récents de transfert de chiralité au sein de cages tripodes. Ensuite nos résultats sur le transfert de chiralité au sein d’un nouvel hémicryptophane permettant de contrôler l’hélicité du ligand TPA (et des complexes de cuivre correspondant), seront décrits. Nous avons ensuite étudié un nouvel hémicryptophane basé sur le ligand TBTA pour la catalyse de réactions de cycloadditions catalysée au cuivre, en milieu confiné. Enfin, nous avons préparé une nouvelle cage présentant deux sites de coordination au sein d’une cavité unique dans le but de mimer la structure du site actif des enzymes methane monooxygenases
The main goal of this thesis was to design, prepare and applied new hemicryptophane cages as supramolecular ligand for metal coordination in confined space. In particular, this work aimed at developping new method for the obtention of (i) enantiopures complexes with controlled helicity and (ii) new confined catalyst with enhanced efficiency and selectivity. The first part consist in a comprehensive literrature review about (i) history of the development of such cage compounds, as well as their applications in recognition and catalysis and (ii) recent examples of control and transfer of chirality within tripodal cages. Then, results about how chirality transfer in a new hemicryptophane can controls the propeller arrangement of the tris(2-pyridylmethyl)amine ligand and its corresponding copper-complex will be discussed. We then studied new TBTA-based hemicryptophane cages as new ligands for copper-catalyzed alkyne-azide cycloaddition (CuAAC) in confined space. Finally, new hemicryptophane cages displaying two metal binding-sites in a single cavity have been developed aiming at reproducing the key structure of methane monooxygenases enzymes

Esta pesquisa trata de uma análise do trabalho de dez eletricistas que atuam em espaços confinados de redes subterrâneas de distribuição de energia, na Companhia Estadual de Energia Elétrica, Porto Alegre, RS. Foi identificada a demanda ergonômica dos eletricistas, com base em um método participativo (Análise Macroergonômica do Trabalho) de levantamento e avaliação dos dados, que gerou insumos para a melhoria das condições de trabalho e segurança e, conseqüente, promoção de prevenção de acidentes. A pesquisa revelou que os eletricistas consideram como aspectos mais positivos do trabalho os relacionamentos entre chefia, supervisores e colegas. Em contrapartida, apontam problemas críticos de diversas naturezas: biomecânico/posto, organização do trabalho, ambiental e relacionados à empresa. Também foram identificados níveis elevados de demandas físicas e mentais do trabalho, concluindo-se que o medo, evidenciado no discurso dos eletricistas, é referente ao trabalho com eletricidade e não ao trabalho em espaços confinados. Além disso, a pesquisa apontou cinco procedimentos, considerados como padrões mínimos, para a realização de trabalhos seguros em espaços confinados: reconhecimento, monitoramento da atmosfera, ventilação, treinamento e resgate.Apesar dos eletricistas não terem ciência da existência destes procedimentos, os mesmos foram citados, direta ou indiretamente nas entrevistas, como aspectos relevantes ao trabalho, sendo atribuído a maioria deles um baixo nível de satisfação. Com isso, conclui-se que a implantação de um programa de permissão de entrada em espaços confinados, além de promover a segurança neste ambientes tem relação direta com a satisfação dos trabalhadores.
The focus of this dissertation is the work analysis of ten electricians who act in confined space at underground power lines at the Estate Electricity Company in Porto Alegre, RS. It was identified the electricians’ ergonomic demand items. The research was carried out according to the participatory methods of survey and assessment of data, to improvement of safety and work conditions and, therefore, to prevent accidents. The research disclosed that the electricians have the relationship with their superiors, supervisors, and workmates as the most positive aspect of the job. On the other hand, they point out critical problems from different causes: biomechanical, task organization, environmental, and the ones related to the company. Overload regarding physical and mental work demand has been identified, proving that the fear, evident in the professionals’ speech is about the electricity, and not related to confined underground spaces. Besides, the research also displayed five procedures regarded as minimal standards to execute safe work in confined spaces: recognition, testing and monitoring atmosphere, ventilation, training and rescue. Despite the little knowledge electricians have on this criteria, some points of it were reported, some in an indirect way, during the interviews as relevant aspects to the work, being attributed to most of them a low level of satisfaction. Therefore, it comes to the conclusion that the implantation of a Permit-Requires Space Program, besides promoting accidents prevention in these spaces, has a direct relationship with the workers’ satisfaction.

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Bachelors
Engineering and Computer Science
Electrical Engineering

Nous avons mesure l'effet de couplage entre les deformations elastiques d'un aerogel de silice plein d'helium quatre et l'apparition d'une transition superfluide dans la structure fractale. Deux regimes ont ete mis en evidence et interpretes. Une region singuliere etroite en temperature qui depend de la densite du gel est observee par des mesures de dilatation du gel ainsi que de pression fontaine. Le changement brutal pour la valeur du coefficient de dilatation thermique est en opposition avec des mesures thermodynamiques precedentes sur ce systeme. La contribution reguliere est un effet de tension de surface entre le gel et l'helium, et correspond a de l'helium confine par le potentiel de van der waals des parois de silice. Nous avons largement elucide son importance dans les cas limites de l'adsorption d'un film d'helium d'epaisseur inferieure a une monocouche ou dans le cas d'un gel plein d'helium pres de son point critique liquide-gaz. Sa contribution pour la transition superfluide a ete calculee

A novel experimental technique had been used to investigate the simultaneous transfer of heat and moisture in a simulated building cavity by natural convection. This technique employed two porous plastic plates as the two cavity walls and this arrangement allowed the imposition of a simultaneous moisture gradient on top of a temperature gradient and vice-versa. Both aiding and opposing-flow conditions were investigated for the vertical and horizontal cavity configuration. The aspect-ratio of the experimental cavity used was 7.0 and the fluid investigated was air. The experimental results were correlated in the form of Nusselt and/or Sherwood number versus an appropriately defined Rayleigh number which depended on the type of gradient causing the flow. The Nusselt and Sherwood numbers were found to agree well with the theoretical values of this work obtained from numerical calculation using a finite-difference technique. The temperature, concentration, stream-function and velocity fields from the numerical calculation also augmented the experimental results. As no previous results on the rate of moisture-transfer and s interaction with the rate of heat-transfer in an actual building cavity were available, the results of this work addresses this gap in the literature. Under the conditions investigated, which corresponded to the actual temperature and moisture gradients in a typical building cavity in New Zealand, the simultaneous temperature gradient had increased significantly the rate of moisture transfer while the presence of the simultaneous moisture gradient had not increased significantly the rate of heat transfer.

A novel cooling mechanism based on evaporation of thin liquid films is presented for thermal management of confined heat sources, such as microprocessor hotspots. The underlying idea involves utilization of thin nanoporous membranes for maintaining microscopically thin liquid films by capillary action, while providing a pathway for the vapor generated due to evaporation at the liquid-vapor interface. The vapor generated by evaporation is continuously removed by using a dry sweeping gas keeping the membrane outlet dry. This thesis presents a detailed theoretical, computational and experimental investigation of the heat and mass transfer mechanisms that result in dissipating heat. Performance analysis of this cooling mechanism demonstrates heat fluxes over 600W/cm2 for sufficiently thin membrane and film thicknesses (~1-5µm) and by using air jet impingement for advection of vapor from the membrane surface. Based on the results from this performance analysis, a monolithic micro-fluidic device is designed and fabricated incorporating micro and nanoscale features. This MEMS/NEMS device serves multiple functionalities of hotspot simulation, temperature sensing, and evaporative cooling. Subsequent experimental investigations using this microfluidic device demonstrate heat fluxes in excess of 600W/cm2 at 90 C using water as the evaporating coolant. In order to further enhance the device performance, a comprehensive theoretical and computational analysis of heat and mass transfer at micro and nanoscales is carried out. Since the coolant is confined using a nanoporous membrane, a detailed study of evaporation inside a nanoscale cylindrical pore is performed. The continuum analysis of water confined within a cylindrical nanopore determines the effect of electrostatic interaction and Van der Waals forces in addition to capillarity on the interfacial transport characteristics during evaporation. The detailed analysis demonstrates that the effective thermal resistance offered by the interface is negligible in comparison to the thermal resistance due to the thin film and vapor advection. In order to determine the factors limiting the performance of the MEMS device on a micro-scale, a device-level detailed computational analysis of heat and mass transfer is carried out, which is supported by experimental investigation. Identifying the contribution of various simultaneously occurring cooling mechanisms at different operating conditions, this analysis proposes utilization of hydrophilic membranes for maintaining very thin liquid films and further enhancement in vapor advection at the membrane outlet to achieve higher heat fluxes.

The flows that may result from the release of a buoyant fluid from a small source in a confined space are varied and complex, depending on the source characteristics, the confining geometry and container ventilation. Previous work has generally been based on the 'filling-box' model (Baines & Turner 1969). This model, however, may only be applied when the source has little or no initial momentum, is in a container with a height/width aspect ratio less than unity and does not interact with the side boundaries. In this thesis some situations in which the 'filling-box' model may not be applied are investigated. In chapter 1 the 'filling-box' model and the work based on it are reviewed and its limitations discussed. Sources are usually modelled as a turbulent jet, plume or buoyant jet; thus in chapter 2 the established properties of jets and plumes are summarised using established theoretical arguments and experimental results. In order to improve some of the theoretical predictions, the effects of previously neglected second order terms and intermittency factor variation are investigated. In most practical situations the source is a buoyant jet. In chapter 3 the flow of an initially horizontal buoyant jet is examined, concentrating on obtaining simple analytical results from the conservation equations and investigating the effect of the nature of the entrainment assumption. The effect of source momentum is examined in chapter 4, in which the flow of a vertical jet with high initial momentum flux in a long, ventilated tunnel is studied. The bulk flow variables are deduced and compared with experimental measurements. A method for calculating the total number of vents required to vent the source fluid is given - this result is particularly important in applications to hazardous releases. In chapter 5 the effect of the aspect ratio, a, on the 'filling-box' model is investigated. It is found that when the aspect ratio is very large (a > 6) the flow is quite different to that observed in the 'filling-box' case. Theoretical models are derived both when a > 6 and when a < 6, and the results are compared with experimental measurements. In chapter 6 the study of chapter 5 is extended, investigating the effect of placing the tank at an angle to the vertical. The flow in the large aspect ratio case is significantly different to that of chapter 5 and is modelled theoretically, comparing the predictions with experimental measurements. Finally, in chapter 7 the general results are reviewed. The current knowledge of flows resulting from buoyant releases in a confined space is then summarised in a simple tabular form, which also indicates areas for future research.

The aim of the project is to explore 3D localisation of a sensor “pill”, contained in an enclosed vessel, using multiple acoustic transducers mounted on the pill‟s surface. The thesis suggests strategies for placement, excitation and synchronisation of the transmitters on the pill and receivers on the vessel wall to deliver 3D localisation. Motivation for the project has emerged from the desire to develop wireless sensor networks to monitor the internals of industrial processes. A major challenge relates to the ability to accurately determine the location of the pill within the vessel, in the presence of multipath reflections. The main challenges relate to the determination of suitable transmission methodologies and synchronisation strategies to allow accurate localisation. The pill has to be a finite size in order to contain the required sensor hardware and transducers must be mounted on the surface of the pill such that signals are able to propagate directly to receivers on the vessel wall. This presents challenges in optimising the transmitter and receiver layout to maximise signal strength and also to determine how the separation of multiple transmitters on the pill impacts localisation accuracy. Time-Difference-of-Arrival (TDOA) has been investigated as a localisation technique, with simulations revealing that the separation of transmitters on the pill influences the accuracy. By modifying the standard TDOA equations with offset knowledge it has been demonstrated, in simulation, that this error can be reduced and by uniquely coding transmitters it is possible to resolve rotation of the pill in the vessel allowing further reduction in localisation error. Simulations have investigated how the location of receivers on the vessel wall influences the localisation error when the TDOA values are compromised by noise. It has been demonstrated that by mounting receivers at the extremities of the vessel the localisation error of the pill can be reduced. Work has also been undertaken to characterise both the vessel reflection properties and also the transmitter beam profile to allow a suitable transmitter layout on the pill to be determined. Simulations, supported by experimental results, have shown that a curved vessel surface can focus the reflected signals and therefore compromise peak detection signal methodologies. As a result amplitude thresholding is suggested for detecting received signals. The research is substantiated with a simple demonstrator that suggests, for both Time-of-Flight (TOF) and Time-Difference-of-Arrival techniques, that the location of the pill can be determined with an accuracy of ± 5 cm throughout a 250 litre vessel. This is the first time that underwater localisation in a confined space using multiple transmitters on the surface of a sensor “pill” has been reported.

Many workers die each year from work-related confined space incidents. The rate of confined space fatalities in Australia was found to be comparable to similarly industrialised countries; and an examination of the aetiologies involved found fatalities were approximately equally from both atmospheric hazards and from physical hazards. Up to 17% of fatalities were found to be those undertaking rescue, overwhelmingly from hazardous atmospheres. Strategies to reduce confined space fatalities were developed.

Evaluaiton des champs thermiques de convection et des regimes d'ecoulement (pour un nombre de rayleigh superieur a 10**(10)) dans une piece d'habitation caracterisee par des conditions de temperatures de surface : un mur vertical chaud, le mur oppose froid et les quatre autres faces a la meme temperature

A study has been performed in the design and fabrication of deployable borehole robots into confined spaces. Three robot systems have been developed to perform a visual survey of a subterranean space where for any reason humans could not enter. A 12mm diameter snake arm was designed with a focus on the cable tensions and the failure modes for the components that make the snake arm. An iterative solver was developed to model the snake arm and algorithmically calculate the snake arms optimal length with consideration of the failure modes. A robot was developed to extend the range capabilities of borehole robots using reconfigurable borehole robots based around established actuation and manufacturing techniques. The expected distance and weight requirements of the robot are calculated alongside the forces the robot is required to generate in order to achieve them. The whegged design incorporated into the tracks is also analysed to measure the capability of the robot over rough terrain. Finally, the experiments to find the actual driving forces of the tracks are performed and used to calculate the actual range of the robot in comparison to the target range. The potential of reconfigurable mobile robots for deployment through boreholes is limited by the requirement for conventional gears, motors, and joints. This chapter explores the use of smart materials and innovative manufacturing techniques to form a novel concept of a self-folding robotic joint for a self-assembling robotic system. The design uses shape memory alloys fabricated in laminate structures with heaters to create folding structures.

This research aims to describe the effect which changing the geometry of confining structures has on transient aerodynamic effects induced by passing high-speed trains. A moving-model high-speed train was fired past walls, partially-enclosed tunnels, and single-track tunnels. A control experiment was carried out in the open air. 3D air velocity components and static pressure were measured inside the structures. The main findings are as follows. The durations and magnitudes of the pressure loads and maximum air velocities were found to be dependent on: the lateral separation of the walls; whether walls on both sides of the tracks are placed symmetrically or asymmetrically; the longitudinal positioning of the sensor in relation to the length of the tunnel; the cross-sectional area of the tunnel; the tunnel’s length in relation to the train’s length; and, finally, the size of an opening in the cross-section of a tunnel in relation to the tunnel’s internal perimeter. Maximum velocities were affected by confinement as a result of changes to: helical vortices in the wake; durations and magnitudes of the pressure fluctuation around the tail; the piston effect in tunnels; the boundary layer shape; and secondary flows induced by pressure gradients in the tunnel cross-section caused by vents.

In this thesis, density functional theory is employed in the study of two kinds of systems that can be considered to be biomimetic in their own ways. First, three binuclear metal complexes, synthesized by the group of Prof. Ebbe Nordlander, have been investigated. The complexes are designed to resemble the active sites of phosphatase enzymes and have been examined in complexes where either two Zn(II) ions or one Fe(III) and one Mn(II) ion are bound. These dinuclear compounds were studied as catalysts for the hydrolysis of bis(2,4-dinitrophenyl) phosphate and the transesterification of 2-hydroxypropyl p-nitrophenyl phosphate, which are model systems for the same reactions occurring in DNA or RNA. It was found that the two reactions take place in similar ways: a hydroxide ion that is terminally bound to one of the metal centers acts either as a nucleophile in the hydrolysis reaction or as a base in the transesterification. The leaving groups depart in an effectively concerted manner, and the formed catalyst-product complexes are predicted to be the resting states of the catalytic cycles. The rate-determining free energy barriers are identified from the catalyst-product complex in one catalytic cycle to the transition state of nucleophilic attack in the next. Another type of biomimetic modeling is made with an aim of imitating the conceptual features of selective binding of guests and screening them from solute-solvent interactions. Such features are found in so-called nanocontainers, and this thesis is concerned with studies of two capsules synthesized by the group of Prof. Julius Rebek, Jr. First, the cycloaddition of phenyl acetylene and phenyl azide has experimentally been observed to be accelerated in the presence of a capsule. Computational studies were herein performed on this system, and a previously unrecognized structure of the capsule is discovered. Two main factors are then identified as sources of the rate acceleration compared to the uncatalyzed reaction, namely the reduction of the entropic component and the selective destabilization of the reactant supercomplex over the transition state. In the second capsule study, the alkane binding trends of a water-soluble cavitand was studied. It is found that implicit solvation models fail severely in reproducing the experimental equilibrium observed between binding of n-decane by the cavitand monomer and encapsulation in the capsule dimer. A mixed explicit/implicit solvation protocol is developed to better quantify the effect of hydrating the cavitand, and a simple correction to the hydration free energy of a single water molecule is proposed to remedy this. The resulting scheme is used to predict new hydration free energies of the cavitand complexes, resulting in significant improvement vis-à-vis experiments. The computational results presented in this thesis show the usefulness of the quantum chemical calculations to develop understanding of experimental trends observed for substrate binding and catalysis. In particular, the methodology is shown to be versatile enough such that experimental observations can be reproduced for such diverse systems as studied herein.

At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 5: Manuscript.

In 2006, a tragic accident took place at the Sullivan mine in Kimberley, British Columbia. Four people died as the result of their entry into an oxygen-depleted sampling station located at the toe of a waste dump. The dump had been in active use for over 50 years and the sampling shed for about 5 years without any problem. The accident was reported as being unprecedented in the history of mining. The accident shows that reclamation sites can be an atmospheric danger only recognizable if a risk assessment is carried out on a regular basis for many years after closure. It is important to conduct regular assessments since there are physical, chemical and environmental factors that affect oxygen-depletion in waste dumps that change over time. In this thesis, an Atmospheric Fuzzy Risk Assessment (AFRA) tool was devised to recognize confined space dangers at sulfide waste dumps undergoing reclamation. The tool is a fuzzy expert system to transfer knowledge on atmospheric hazards. Modeling the complex environment of a waste dump where internal and external factors change temporally and spatially using conventional mathematical tools is a difficult task. Therefore, a technique based on fuzzy logic and weighted inferencing was applied since this method relies on a heuristic approach that allow for case–based reasoning. AFRA can help mining engineers and other safety professionals to recognize this type of danger while developing a confined space inventory at any site. The second goal of this research has been to create an application for hand-held pocket PCs and/or Smart phones that can be used by first-responders to provide answers about a possible confined space situation to help them decide to enter or not into that space.

Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2011.
ENGLISH ABSTRACT: This thesis forms part of the Control Surfaces in Confined Spaces (CoSICS) project conducted at Stellenbosch University. The aim of this project is reduction of control surface actuator footprints on the existing wing structures of commercial airliners such as the Airbus A320 and A330. This is achieved by reducing control surface hinge moments through the application of trailing edge tabs. This results in smaller actuator requirements. The first tier of the project focussed on the geometric optimisation of the tab applied to an aileron. This thesis focusses on the development of dynamic control of the aileron through either tab-only or concurrent tab and aileron actuation. In the effort to develop dynamic control, a fully coupled generalised dynamic model of the tab and aileron is derived and presented. Through linearisation of this model, linear controllers are developed. Two distinctly different controllers are presented; the first controller makes use of classical methods for control of the tab-only actuated aileron and the second controller makes use of modern control techniques such as full state feedback to facilitate controlled concurrent tab and aileron actuation. Each proposed controller is evaluated in terms of dynamic performance, robustness, disturbance rejection and noise immunity. Based on the controller development, a summary of dynamic actuator requirements is given. Practical verification of the model and the controller performance is then undertaken. The development of the necessary hardware and software is also presented. The concept of aileron control through tab-only actuation and concurrent tab and aileron actuation is then validated. Conclusion are then drawn about the accuracy of the theoretical model and the practical performance of the controllers. The thesis is concluded with recommendations for future work to increase the fidelity of the model. Important aspects about the practical implementation of the concept on commercial jetliners are also summarised.
AFRIKAANSE OPSOMMING: Hierdie tesis is deel van die Control Surfaces in Confined Spaces1 projek by Stellenbosch Universiteit. Die doel van hierdie projek behels die verkleining van die aktueerder spasie en ondersteunings struktuur vereistes, op die bestaande vlerk struktuur van kommersiële vliegtuie soos die Airbus A320 en Airbus A330. Dit is bereik deur die vermindering van die beheeroppervlak skarnier se draaimoment met behulp van aerodinamiese hulpvlakke. Kleiner aktueerders word dus benodig. Die eerste stadium van die projek fokus op die geometriese optimisering van die hulpvlak op ’n aileron. Hierdie tesis fokus op die ontwikkeling van dinamiese beheer van die aileron deur middel van hulpvlak aktueering alleenlik of met die gelyktydige aktueering van die hulpvlak en aileron. In die proses van onwikkeling is ’n volgekoppelde veralgemeende dinamiese model van die hulpvlak en aileron afgelei en voorgelê. Deur middel van linearisasie van die model is linieêre beheerders ontwikkel. Tans is twee verskillende beheerders ontwikkel. Die eerste beheerder is gebaseer op die klassieke metodes en maak staat op die aktueering van die hulpvlak alleenlik. Die tweede beheerder maak gebruik van moderne beheer tegnieke soos vol toestand terugvoer om gelyktydige hulpvlak en aileron aktueering te realiseer. Die beheerders is elk geëvalueer in terme van dinamiese gedrag, robuustheid, versteurings verwerping en ruis verwerping. Die beheerstelsel ontwikkeling lei tot ’n opsomming van die dinamiese aktueerder vereistes. Dit word gevolg deur praktiese verifikasie van die model en die beheerstelsel gedrag. ’n Opsomming van die ontwikkeling van nodige hardeware en sagteware word voorgelê. In hierdie proses is die konsep van beide hulpvlak alleenlike aktueering en gelyktydige hulpvlak en aileron aktueering bewys. Gevolgtrekkings word gemaak oor die akkuraatheid van die model en die praktiese gedrag van die beheerders. Die tesis word afgerond met voorstelle vir toekomstige werk wat die model se betroubaarheid kan verbeter. Verder word belangrike punte oor die praktiese aspekte van konsep implementering op kommersiële vliegtuie ook uitgelig.

The subject of the thesis is the derivation of non-local diffusion equations from kinetic models with heavy-tailed equilibrium in velocity. We are particularly interested in confining the kinetic equations and developing methods that allow us, from the confined kinetic models, to derive confined versions of non-local diffusion equations.

The basis of mixing ventilation is the airflow supply to the room by means of jets initiatedfrom the ventilation diffusers. To avoid the draught problem, the design of mixing ventilationmakes uses the throw term, which is defined as the distance to the supply air terminal inwhich the jet centreline mean velocity is decreased to a given value. Traditionally, the throw ismeasured by the supply air device manufacturer. The throw is applied by designers to estimatethe velocity levels in the occupied zone. A standard for determining the throw is the CENstandard CEN/TC156/WG4 N86 "Draft Standard. Air terminal Devices. AerodynamicsTesting And Rating For Mixed Flow Application".The measurement of the throw is very time consuming even with the free jets and theinfluence of the room (the effect of confinement) is not considered. The objective of thepresent study is to give a basis for modifying the existing design and testing method used topredict the velocities in the occupied zone during the design process. A new method whichmay probably be more easier than the existing methods and at the same time give a betterprecision by including the confinement effect.In this thesis two methodological systems of experiment and numerical simulations have beenused. The numerical predictions are used in comparison with the measurements. Thereasonable agreement of the above mentioned methods is implemented to numerical study ofthe other room configurations which are not experimentally studied. This examining methodallows the possibility of studying a lot of configurations and in this manner generalising of theresults. Although the experimental part was made for both model-scale and full-scale testrooms, a large amount of data was obtained for a new test room whose dimension aresystematically varied. All of studies have been made for the isothermal case and themeasurements of velocities and pressures conducted along the room perimeters. The effect ofshort and deep rooms on the properties of the jet ( velocities, pressure, integral scale, jetmomentum, the rate of spreading of jet and turbulence intensities) have been carried out.Some old and recent investigations have been examined. Specially the concept of correlationsfrom open to closed rooms is criticised. It is also shown that the flow field in a confined roomis affected by many other factors than the Reynolds number. The surface pressure on theperimeters was used to calculate the reaction forces at the corners which causes recirculatingbubbles at corners. A study of the turbulent axisymmetric jet which is the basic element inturbulent shear flows and some restrictions of the traditional measurement techniques at theregion of interest in ventilation applications are discussed. The jet momentum is measured byweighing on a balance. Also a study of jets which collide with a wall , that is impinging jet,the effect of walls and confinement on the jet momentum have experimentally andnumerically been carried out. A new momentum balance model was developed for both thefree jet and confined one. An empirical relation has been found for estimation of the room’srotation centre which is used for validation of CFD results.Finally, it is found that the jets in a ventilated room which are a combination of free jet, walljet and impinging jet differ from the traditional wall jets. The rate of spreading of the jet andthe maximum velocity decay in a ventilated room are also different depending on the roomsize and its confinement.

Methane hydrate nucleation and growth in porous model carbon materials illuminates the way towards the design of an optimized solid-based methane storage technology. High-pressure methane adsorption studies on pre-humidified carbons with well-defined and uniform porosity show that methane hydrate formation in confined nanospace can take place at relatively low pressures, even below 3 MPa CH4, depending on the pore size and the adsorption temperature. The methane hydrate nucleation and growth is highly promoted at temperatures below the water freezing point, due to the lower activation energy in ice vs. liquid water. The methane storage capacity via hydrate formation increases with an increase in the pore size up to an optimum value for the 25 nm pore size model-carbon, with a 173% improvement in the adsorption capacity as compared to the dry sample. Synchrotron X-ray powder diffraction measurements (SXRPD) confirm the formation of methane hydrates with a sI structure, in close agreement with natural hydrates. Furthermore, SXRPD data anticipate a certain contraction of the unit cell parameter for methane hydrates grown in small pores.

Methane hydrate nucleation and growth in porous model carbon materials illuminates the way towards the design of an optimized solid-based methane storage technology. High-pressure methane adsorption studies on pre-humidified carbons with well-defined and uniform porosity show that methane hydrate formation in confined nanospace can take place at relatively low pressures, even below 3 MPa CH4, depending on the pore size and the adsorption temperature. The methane hydrate nucleation and growth is highly promoted at temperatures below the water freezing point, due to the lower activation energy in ice vs. liquid water. The methane storage capacity via hydrate formation increases with an increase in the pore size up to an optimum value for the 25 nm pore size model-carbon, with a 173% improvement in the adsorption capacity as compared to the dry sample. Synchrotron X-ray powder diffraction measurements (SXRPD) confirm the formation of methane hydrates with a sI structure, in close agreement with natural hydrates. Furthermore, SXRPD data anticipate a certain contraction of the unit cell parameter for methane hydrates grown in small pores.

La technologie des réseaux de capteurs sans fil (RCSF) est l’un des éléments constitutifs de l’Internet des objets (IoT). En raison de leurs caractéristiques de déploiement facile et de leur flexibilité, ils sont utilisés dans de nombreux domaines d’application. Les réseaux à faible consommation et à perte (LLN) sont un type spécial de WSN dans lequel les noeuds sont largement limités en ressources. Convergecast est l’un des modes de communication de base, dans lequel tout le trafic du réseau est destiné à une destination prédéfinie appelée collecteur. Tout en prenant en compte les domaines d’applications IoT, convergecast n’est pas le seul mode de communication sur le réseau. Le récepteur doit envoyer des commandes à certains capteurs pour effectuer des actions. Dans cette application, anycast est un autre mode de communication de base. Dans anycast, le trafic provenant du récepteur est destiné à tout membre d’un groupe de récepteurs potentiels du réseau.Les LLN sont formés de noeuds de capteurs statiques et changent rarement de position. En raison des contraintes de ressources strictes imposées au calcul, à l’énergie et à la mémoire des LLN, la plupart des protocoles de routage ne prennent en charge que les réseaux statiques. Cependant, la mobilité est devenue une exigence importante pour de nombreuses applications émergentes. Dans ces applications, certains noeuds sont libres de se déplacer et de s’organiser dans un réseau connecté. La topologie changerait continuellement en raison du mouvement des noeuds et de l’instabilité des liaisons radio. Il s’agit d’une tâche difficile pour la plupart des protocoles de routage des réseaux LLN afin de s’adapter rapidement au mouvement et de reconstruire la topologie en temps voulu. Le but de cette thèse est de proposer un support de mobilité efficace pour les protocoles de routage dans les réseaux LLN. Nous nous concentrons sur convergecast et anycast, qui sont les modes de communication les plus utilisés dans les réseaux LLN, dans les scénarios de réseau mobile. Nous proposons un mécanisme d’amélioration, nommé RL (RSSI and Level),pour prendre en charge les protocoles de routage dans les réseaux LLN convergecast en mobilité. Ce mécanisme aide le protocole de routage à prendre des décisions plus rapides pour la détection de la mobilité et la mise à jour des voisins du saut suivant,mais souffre d’une surcharge importante. Nous proposons une gestion dynamique des messages de contrôle pour améliorer les performances de RL et l’implémentons en plus du protocole de routage pour réseau à faible consommation (RPL) et nous l’avons nommé RRD (RSSI, Rank and Dynamic). Après une prise en compte de l’hystérésis de la zone de couverture de la plage de transmission des noeuds, nousavons optimisé RRD. Cette version améliorée s’appelle RRD +. Sur la base de RRD+, nous avons proposé MRRD + (Multiple, RSSI, Rank et Dynamic) pour prendre en charge plusieurs puits dans les réseaux LLN convergecast en mobilité. ADUP (Adaptive Downward / Upward Protocol) est une solution de routage prenant en charge simultanément convergecast et anycast dans les réseaux LLN. Nous avons évalué les performances de nos contributions à la fois en simulation avec le simulateur Cooja et en expérience (uniquement pour ADUP) sur des motosTelosB. Les résultats obtenus en simulation et en expérience confirment l’efficacité de nos protocoles de routage
Wireless Sensor Networks (WSNs) technology is one of the building blocks ofthe Internet of Things (IoT). Due to their features of easy deployment and flexibility,they are used in many application domains. Low-Power and Lossy Networks(LLNs) are a special type of WSNs in which nodes are largely resources constrained.For LLNs, convergecast is one of the basic traffic modes, where all traffic in the networkis destined to a predefined destination called the sink. While considering theIoT application domains, convergecast is not the only traffic mode in the network.The sink needs to send commands to certain sensors to perform actions. In this application,anycast is another basic traffic mode. In anycast, the traffic from the sinkis destined to any member of a group of potential receivers in the network.Traditionally LLNs are formed by static sensor nodes and rarely change positions.Due to the strict resource constraints in computation, energy and memory ofLLNs, most routing protocols only support static network. However, mobility hasbecome an important requirement for many emerging applications. In these applications,certain nodes are free to move and organize themselves into a connectednetwork. The topology would continuously change due to the movement of nodesand radio links instability. This is a hard task for most routing protocols of LLNs toadapt rapidly to the movement and to reconstruct topology in a timely manner.The goal of this thesis is to propose an efficient mobility support for routingprotocols in LLNs. We focus on convergecast and anycast, which are the most usedtraffic modes in LLNs, in mobile network scenarios.We propose an enhancement mechanism, named RL (RSSI and Level), to supportrouting protocols in convergecast LLNs in mobility. This mechanism helps routingprotocol make faster decisions for detecting mobility and updating next-hop neighborsbut suffers from high overhead. We propose a dynamic control message managementto enhance the overhead performance of RL and implement it on top ofRouting Protocol for Low-power and Lossy network (RPL) and we named it RRD(RSSI, Rank and Dynamic). After taking into account hysteresis of the coveragezone of the transmission range of nodes, we optimized RRD. This enhanced versionis called RRD+. Based on RRD+, we proposed MRRD+ (Multiple, RSSI, Rankand Dynamic) to support multiple sinks in convergecast LLNs in mobility. ADUP(Adaptive Downward/Upward Protocol) is a routing solution that supports bothconvergecast and anycast in LLNs concurrently.We evaluated the performance of our contributions in both simulation usingCooja simulator and experiment (only for ADUP) on TelosB motes. The resultsobtained in both simulation and experiment confirm the efficiency of our routingprotocols

Cette thèse se focalise sur le design, la synthèse et la caractérisation photophysiques de complexes de platine(II) neutres contenant un ligand chromophore tridenté et un ligand auxiliaire monodenté avec des groupes fonctionnels différents. De tels complexes montrent des changements drastiques de leurs propriétés de photoluminescence à cause de leur auto-assemblage, déclenché par l’établissement de faibles liaisons non covalents tels que l’empilement p-p et des interactions métallophiliques. Il a été démontré que ces complexes de platine(II) peuvent être attaché de manière covalente à des surfaces de silice et d’or mais aussi encapsulé dans des particules de polymère. Les propriétés d’autoassemblage de complexes de platine(II) amphiphiles ont également été étudiées en détails. Comprendre le comportement d’un complexe de platine dans un mélange de solvant nous a permis d’en apprendre plus sur le co-assemblage supramoléculaire de deux complexes de platine(II) différents. Cette approche conduit à la formation de fibres solvatochromiques avec des propriétés photophysiques spécifiques et réversibles. Les composés étudiés et leur auto-assemblage sonti ntéressant pour le développement de nouveaux matériaux fonctionnels aux applications sensoriels et réactives à certains stimuli
This thesis focuses on the design, synthesis and the photophysical characterisation of luminescent neutral platinum(II) compounds containing a tridentate chromophoric ligand and a monodentate ancillary moiety with different functionalities. Such complexes exhibited drastic changes to their photoluminescence properties upon self-assembly, triggered by the establishment of weak noncovalent p-p stacking and metallophilic interactions. It was demonstrated that these platinum(II) complexes can be covalently attached to silicon and gold substrates but also encapsulated into polymer particles. The self-assembly properties of amphiphilic platinum(II) complexes have also been intensively studied. Understanding the behaviour of one complex in a solvent mixture allowed further investigation into the supramolecular co-assembly of two different platinum(II) complexes. This approach leads to the formation of solvatochromic fibers with specific and reversible phototophysical properties. The investigated compounds and their assemblies were useful for the development of novel functional materials for sensing or stimuli-responsiveness applications

Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2010.
ENGLISH ABSTRACT: This thesis describes the first project relating to the Control Surfaces in Confined Spaces (CoSICS) project at Stellenbosch University. The aim of CoSICS project is to reduce the size of control surface actuators, and this thesis considers the aileron system of commercial aircraft such as the Airbus A320 and A330. Specifically the project aims to reduce the aileron hinge moment, as this will result in smaller actuators. Possible methods are discussed where aerodynamic forces are used to reduce the aileron hinge moment through the use of a wing-aileron-tab configuration. In order to examine the use of the configuration, first order aerodynamic modelling is performed using two-dimensional thin-aerofoil theory, which is also extended to a basic three-dimensional approximation. To determine the maximum reduction in hinge moment several optimisations are performed where only the tab chord length is varied, both tab and aileron chord lengths are varied, and finally the tab chord length and aileron span are varied. The optimisation methods used, namely the gradient-based sequential quadratic programming (SQP) and a real-encoded genetic algorithm (REGA) are discussed in detail and include general implementations which are then applied to the problem. The optimisations performed are dual-layered where optimal deflection angles are determined as well as the optimal geometry. The results of the optimisation are tested using a roll manoeuvre in a specially developed Simulink simulation environment for this purpose. The study produces results where new hinge moment values are an order of magnitude smaller than those of the old configuration, while maintaining suitable lift and rolling moment coefficients. The optimisation and simulation infrastructure developed in this thesis provides a platform for higher-fidelity models and components being developed in future work to provide higher fidelity results.
AFRIKAANSE OPSOMMING: Hierdie tesis beskryf die eerste projek in die Control Surfaces in Confined Spaces-projek1 (CoSICS-projek) uitgevoer by die Universiteit Stellenbosch. Die doel van die COSICs-projek is om die grootte van beheervlak aktueerders te minimeer en hierdie tesis handel oor die aileron stelsel van kommersiële vliegtuie soos die Airbus A320 en A330. Die doel van hierdie tesisis om die skarnier draaimoment van die aileron te minimeer deur aërodinamiese kragte in te span in ’n vlerk-aileron-hulpvlak konfigurasie. Eerste-orde aërodinamiese modelle is afgelei met behulp van twee-dimensionele dunvlerkteorie en is gebruik om die konfigurasie te analiseer. ’n Eerste orde drie-dimensionele benadering is ook ontwikkel. Om die maksimum vermindering in die skarnier draaimoment te bepaal, is verskeie optimerings uitgevoer waar eers die hulpvlak se koordlengte gevarieer word, daarna beide die aileron en hulp-vlak se koordlengtes en laastens die hulp-vlak se koordlengte en wydte. Die twee optimerings metodes wat gebruik is, nl. ’n sekwensiële kwadratiese programmerings (SKP) tegniek, en ’n reële getal-geënkodeerde genetiese algoritme (RGGA), word bespreek en ontwikkel voor hulle toegepas word op die probleem. Twee-vlak optimerings word uitgevoer waar beide die optimale defleksiehoeke en die optimale geometrie bepaal word. Die resultate van die optimering word daarna getoets deur middel van ’n rol maneuver wat uitgevoer word in ’n Simulink simulasie omgewing wat daarvoor geskep is. Hierdie studie lei tot goeie resultate met skarnier draaimoment waardes ’n ordegrootte kleiner as dié van die vorige stelsel, terwyl goeie waardes van rol-moment en verheffingskrag koëffisiënte behou word. Die optimering en simulasie infrastruktuur wat hier ontwikkel word verskaf ’n platform vir meer akkurate modelle en komponente wat ontwikkel word in toekomstige projekte om meer akkurate resultate te lewer.

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Fundação de Amparo à Pesquisa do Estado de Goiás - FAPEG
The space category received more attention in the literary studies in the late decades. It is observed that this category has much importance in the literary text as any other element. thus far prioritized as, for example, the time. The dissertation is based mainly on the Topoanalisys theory by Borges Filho and, through his methodology; a study was done regarding the spatiality in the work Vila dos Confins (1974) by Mario Palmério. To do so, we used Bachelard (2008) theoretical work and Brandão (2013). We could verify that some parts of Brazil depicted in the book were still barely known: rivers, forests and dirt roads are always described in the narrative route. The house also presents itself as an essential element in the text and contributes to the understanding in order to establish positive-affective and negativeaffective relationships with the characters, which Borges Filho (2007) calls topopatia. Corroborating the analysis of this literary corpus, this dissertation examines also the dialogue established between space, memory and identity in the light of the theories of Candau (2014), Silva (2008), among others. These issues are analyzed in the context of the book, therefore, in a way, state and picture a society rooted in a particular location. In this sense, our study aims to better understand the work of a regionalist nature written by a politician-writer analyzing the spaces. It is important to note that the relationship of the characters with the space they inhabit or go through has a great influence in the plot in order to lead and contribute to the end of the novel. The narrator presents intriguing facts that permeate the text in order to transform the space of the newly emancipated county into a political battleground, as the electoral dispute is present throughout the whole narrative.
A categoria espaço recebeu atenção maior nos estudos literários das últimas décadas. Nota-se que tal categoria tem tanta importância na obra literária quanto qualquer outro elemento até então priorizado como, por exemplo, o tempo. A dissertação se fundamenta principalmente pela teoria da Topoanálise de Borges Filho e, através de sua metodologia, foi feito um estudo da espacialidade na obra Vila dos Confins (1974) de Mário Palmério. Para tanto, foi utilizado também o aporte teórico de Bachelard (2008), Brandão (2013). Pudemos constatar que espaços de um Brasil ainda quase não desbravado são comuns na obra: rios, matas, estradas de terra batida são sempre descritas no percurso da narrativa. A casa também se apresenta como um elemento essencial no texto e contribui com o entendimento do mesmo ao imprimir relações afetivo-positivas e afetivo-negativas com as personagens, o que Borges Filho (2007) chama de topopatia. Corroborando com a análise desse corpus literário, esta dissertação examina, ainda, o diálogo estabelecido entre espaço, memória e identidade, à luz das teorias de Candau (2014), Silva (2008), dentre outros. Esses temas são analisados no contexto da obra, pois, de certa forma, afirmam e enraízam a sociedade em um determinado local. Nesse sentido, o nosso estudo tem por finalidade entender melhor uma obra de cunho regionalista escrita por um escritor-político através da análise dos espaços que esta apresenta. É importante salientar que, as relações das personagens com o espaço que o habitam ou percorrem têm uma influência muito grande dentro da trama de forma a implicar e contribuir com o desfecho do romance. O narrador apresenta fatos intrigantes que permeiam o texto de forma a transformar o espaço do recém-emancipado município em um campo de batalhas político, uma vez que a disputa eleitoral está presente durante toda a narrativa.

Thesis (MScEng)--Stellenbosch University, 2012.
ENGLISH ABSTRACT: The successful design, implementation and testing of a feedback control system for tab-deflection control of a shape memory alloy (SMA) based control surface actuator is presented. The research is performed as part of the Control Surfaces in Confined Spaces (CoSICS) research project conducted at Stellenbosch University. The research group investigates ways to provide control surface actuation in size-restricted spaces in commercial aircraft such as the Airbus A320 and A330. This is achieved by investigating the concept of trailing edge tabs to reduce the required torque load, resulting in reduced actuator requirements enabling the use of smaller actuators. This thesis contributes to the project by investigating the possibility of using SMA-based actuators in reduced hinge moment requirement applications. An SMA-based tab actuator demonstrator design is presented. Mathematical models are derived for the SMA material, thermodynamics and actuator geometry. The models are combined to formulate an SMA-based control surface actuator model. The model is utilised in four tracking feedback controller designs; two based on linear and two based on non-linear control techniques. The manufactured prototype is presented along with the incorporated hardware for controller implementation. System identification follows and validates the three mathematical models. Practical verification of the model and two of the controllers is conducted. The unimplemented controllers are implemented through a validated model simulation. Controller evaluation, based on the dynamic controller performance, is conducted. The results validate the concept of using an SMA actuator for tab-deflection control and indicate important limitations for the intended application.
AFRIKAANSE OPSOMMING: Die tesis behels die ontwerp, implementering en toetsing van ’n terugvoer beheerstelsel vir hulpvlak defleksie beheer van ’n vorm-geheue allooi (SMA) gebaseerde aktueerder. Die navorsing vorm deel van die Beheervlakke in Begrensde Ruimtes (CoSICS) navorsingsprojek by Stellenbosch Universiteit. Die CoSICS navorsing behels ’n ondersoek na beheervlak aktueering in beknopte spasies in kommersiële vliegtuie soos die Airbus A320 en A330. Die probleem word aangespreek deur ’n ondersoek na aerodinamiese hulpvlakke wat ’n vermindering in skarnier moment tot gevolg het en sodoende die aktueerder vereistes verminder. Hierdie tesis dra by tot die projek deur die moontlikheid van die gebruik van SMAgebaseerde aktueerders in verminderde skarnier moment vereiste toepassings te ondersoek. ‘n SMA gebaseerde hulpvlak demonstrasie aktueerder ontwerp word voorgelê. Wiskundige modelle vir die SMA materiaal, termodinamika en prototipe geometrie is geformuleer en gekombineer om ‘n SMA gebaseerde beheervlak aktueerder model te ontwikkel. Die model word in vier beheerder ontwerpe toegepas. Twee ontwerpe is op liniëre en twee op nie-liniëre beheer tegnieke gebaseer. Die prototipe en nodige hardeware vir beheerder implementasie is voorgedra. Stelsel identifikasie is toegepas en verifieer die drie wiskundige modelle. Praktiese verifikasie van die model en twee beheerders is gedoen. Die ongeïmplementeerde beheerders is deur die geverifieerde aktueerder model gesimuleer. ‘n Beheerder evaluasie gebaseer op die dinamiese beheerder gedrag word toegepas. Die evaluasie beklemtoon kritiese aspekte en beperkinge in verband met SMA aktueering. Die resultate regverdig die gebruik van ‘n SMA aktueerder vir hulpvlak defleksie beheer en beklemtoon belangrike beperkinge ten opsigte van die voorgestelde toepassing.

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The Brazilian maritime shipping industry is currently under going a fast growing expansion driven by, amongst other reason, Government policies towards encouraging new building ships to the Oil & Gas industry in local shipyards . At the same time , the exploration and production of petroleum demand s chartering a large number of foreign f lag vessels to support its operations. The fast growing fleet counters the fact of the shortage of skilled workforce manning those vessels , notably the Merchant Maritime Officers . Worsening the critical situation the National Council of Immigration issued the Normative Resolution n° 72/2006, with mandatory minimum proportion of Brazilian seafarers after 90 days of cont inuous operation in the Brazilian jurisdiction waters . Moreover , a study ordered by the National Union of Shipowners shows that the turnover of Maritime Officers , in the first years of their career aboard, is about 30 percent. For this reason, this study , from a literature review about Brazilian culture, motivation , work - f amily conflict , confined spaces working and turnover , has develope d into an exploratory and field research , through personal interviews analyzed accordingly with the method of content analysis with seasoned professional s with regard the thematic approach , and Maritime Officers , in order to identify the factors contributing to the turnover of Maritime Officers in the early years of his career aboard. As a result , the study showed that the intrinsic and extrinsic motivators’ agents act continuously directing the behavior of Marit ime Officers to stay or quit the career aboard . In the process of alter ing beha vioral and psychological forces , associated with motivation, the decision making process is influenc ed by a high number of alternatives represented by available employment oppor tunities to the Maritime Officers , the work - family conflicts and the difficulty to adapt working in a confined environment. In the case of Maritime Officers , females’ genre , the situation is even more sensitive because they struggl e to accomplish with the motherhood and wifely role . Therefore , the motivation to stay or quit the c areer aboard is strongly related of seeking fulfillment of personal expectations and the desire to balance personal and professional life
A indústria de transporte marítimo brasileira passa por um momento de forte expansão decorrente, entre outros fatores, de políticas governamentais que incentivam a construção, nos estaleiros nacionais, de navios para serem utilizados em apoio às atividades da indústria de óleo e gás. Ao mesmo tempo, para complementar a frota brasileira, as empresas petroleiras demandam a contratação de grande quantidade de navios estrangeiros para apoiar as suas operações. Este quadro de crescimento da frota, observado, particularmente, nos últimos 10 anos, contrasta com a escassez de mão de obra qualificada para tripular as embarcações, de modo especial dos Oficiais da Marinha Mercante (OMM). Acentuando o contraste, o Conselho Nacional de Imigração editou a Resolução Normativa n° 72/2006, determinando às empresas de navegação, que operam barcos de bandeira estrangeira, a contratação de proporções mínimas de tripulantes brasileiros, após 90 dias contínuos de operação no país. Além disso, estudos encomendados pelo Sindicato dos Armadores, SYNDARMA, apontam que a taxa de evasão dos OMM, nos anos iniciais da carreira embarcada, é de cerca de trinta por cento. Assim, o presente estudo, a partir de uma revisão bibliográfica acerca da história da Marinha Mercante brasileira, da cultura brasileira, da motivação, dos conflitos família-trabalho, do trabalho em espaço confinado e da rotatividade, se desenvolveu em uma pesquisa exploratória e de campo, por meio de entrevistas pessoais, analisadas à luz da técnica da análise de conteúdo, com profissionais de reconhecida experiência com o tema, além de OMM, com o objetivo de identificar os fatores contribuintes para a evasão dos OMM nos anos iniciais da carreira embarcada. Como resultado, o estudo mostrou que os agentes motivadores intrínsecos e extrínsecos agem continuamente direcionando o comportamento dos OMM para a permanência ou saída da carreira embarcada. Nessa alternância de forças psicológicas e comportamentais, associadas à motivação, influenciam no processo decisório as alternativas existentes representadas pelas oportunidades de emprego oferecidas aos OMM, os conflitos trabalho-família e a dificuldade de adaptação ao trabalho em ambiente confinado. No caso dos OMM, do gênero feminino, a situação é ainda mais sensível, pois enfrentam dificuldades para conciliar a vida embarcada com o papel de mãe e esposa. Portanto, a motivação para a permanência ou saída da carreira embarcada está fortemente relacionada à busca pela realização das expectativas pessoais e ao desejo de equilibrar vida pessoal com a profissional.

Nel contesto della fuga dei cittadini Siriani verso la regione del Medio Oriente e Nord Africa e verso l’Europa tra il 2013 e il 2016, questa ricerca avvia una riflessione sul contenuto del diritto di asilo in tre spazi di frontiera del Sud Europa (Lesbo, Sicilia e Melilla) al fine di far luce sui suoi contorni variabili. A partire dall’analisi della riconfigurazione dello spazio Mediterraneo nel post- 2011, sia come regime migratorio che come spazio politico, la ricerca si focalizza sul tema del diritto di asilo mettendo al centro della riflessione il concetto di accesso: accesso al territorio di un paese (ritenuto) sicuro, accesso alla procedura di riconoscimento dell’asilo, e accesso alla prima accoglienza. Inoltre, la ricerca analizza l’agency e la voce dei rifugiati siriani durante i loro percorsi migratori, al fine di contribuire a una migliore comprensione di alcuni fenomeni inediti di cui essi sono stati protagonisti. Tra questi, il più rilevante è costituito dalla sfida alle prescrizioni imposte dal Regolamento Dublino, che ha preso forma in diverse località di frontiera attraverso vari tipi di interazione con (nuovi e vecchi) attori e, in alcuni casi, attraverso veri e propri atti di resistenza, volti a proseguire il viaggio verso i paesi del centro e nord Europa, spesso immaginati come destinazioni finali. Attraverso un’etnografia multi-situata e tramite un approccio comparativo la ricerca esplora i meccanismi attraverso i quali l’agency dei rifugiati si è sviluppata riuscendo talvolta a prevalere su alcune strutture sociali, quali quelle costitutive dei regimi confinari e di governo dei fenomeni migratori. Inoltre essa analizza i contenuti fondamentali della voce dei rifugiati, emersa sia nelle narrazioni riguardo i viaggi verso e attraverso l’Europa che in specifici atti di cittadinanza. Nelle voci dei rifugiati, la percezione di sé quali esseri umani, dunque titolari di specifici diritti fondamentali emerge come dominante e promuove l’interpretazione dei loro percorsi di agency e resistenza come risposte razionali all’attuale processo di svuotamento del diritto di asilo. I movimenti secondari dei rifugiati sono infine ipotizzati come tentativi di rivitalizzare tale diritto, attraverso il suo riempimento con il miglior contenuto possibile.
In the frame of the Syrian citizens’ flight to the MENA region and to Europe between 2013 and 2016, this research reflects on the very content of the right to asylum in three border zones of Southern Europe (Lesvos, Sicily and Melilla) in order to shed light on its variable contours. Starting by an analysis of the reconfiguration of the Mediterranean space in the post-2011, both as migration regime and political space, the research path focuses to the right to asylum issue by putting the question of access at the core: access to the territory of a (supposed to be) safe country, access to the asylum procedure, and access to first reception. Moreover it examines the agency and voice of Syrian refugees during their journeys in order to promote a better understanding of certain inedited social phenomena of which they have been protagonists. The most relevant was the challenge of the prescriptions imposed by the Dublin Regulation, which took shape through various kinds of interactions with (old and new) stakeholders, and in some cases through acts of resistance, aimed at pursuing their journeys to Central the Northern European countries, generally imagined as final destinations. Through a multi-sited ethnography and a comparative approach the research attempted to explore the mechanisms through which refugees’ agency has developed and the main contents of their voice by showing how they have been able to call into question certain social structures, such as those embodied by migration and border regimes. In refugees’ narratives concerning their “ to and throughout Europe, their self-representation as human beings, who are entitled of specific fundamental rights as such, emerges as dominant and foster an interpretation of their paths of agency and resistance as rational answers to the current emptying process of the right to asylum. In other words, their secondary movements appear as attempts to revitalize the right to asylum, by filling it with the better possible content.

Esperienze anomale del sé sono state associate ai disturbi dello spettro schizofrenico. Si ritiene che un debole senso del sé (sé minimale), un disturbato funzionamento corporeo implicito e della sintonizzazione intercorporea con gli altri siano manifestazioni di un sé corporeo disturbato nella schizofrenia (Sz). L’alterazione del sé minimale, correlata ai disturbi del riconoscimento di sé e della discriminazione sé-altro, dipende da deficit nell’ integrazione multisensoriale. Una delle esperienze di base del sé riguarda il senso di appartenenza del corpo (BO) che è legato sia alle parti corporee che al volto, un segno cruciale per la propria identità che consente di distinguerci dagli altri e di differenziarci dagli altri. La Sz è caratterizzata da deficit nel riconoscimento del proprio volto e di quello altrui, nonché da un BO alterato. Pertanto, lo scopo del primo studio è stato quello di integrare queste linee di ricerca indagando la propensione all'Enfacement Illusion (EI) nella Sz. I risultati hanno mostrato come l'EI abbia indotto la malleabilità del confine Sé-Altro sia nei controlli che nei pazienti; l’EI ha influenzato inoltre il confine Altro-Altro, suggerendo come l'EI non sia solo confinato alla sfera del sé, ma influenzi anche il modo in cui discriminiamo gli altri. Il secondo studio aggiunge nuove importanti evidenze nel contesto del sé corporeo nella Sz, focalizzandosi sul processamento implicito del sé corporeo, operazionalizzato nel cosiddetto effetto del vantaggio del sé (SAeff, rotazione mentale motoria più veloce con proprie parti corporee rispetto a quelle altrui in un giudizio di lateralità). I risultati hanno mostrato l'assenza del SAeff nella Sz rivelando un'alterazione nei processi sensorimotori delle proprie parti corporee, suggerendo una potenziale natura motoria distorta del sé minimale. Un altro aspetto cruciale che influenza tale senso del sé è la consapevolezza corporea, la sensazione di essere un sé corporeo nello spazio (sé spaziale), che dipende dall'integrazione di segnali multisensoriali che si verificano all'interno di una porzione di spazio circostante il corpo, lo Spazio Peripersonale (PPS). Il PPS non è fisso, ma si modella dinamicamente attraverso le esperienze motorie, come dopo l'uso di strumenti. Inoltre, l’estensione del PPS varia tra le persone al variare di diverse caratteristiche individuali, come la schizotipia (St). Tuttavia, ancora poco si conosce sulla relazione tra la plasticità del PPS e i tratti di personalità. A questo scopo, abbiamo studiato la plasticità del PPS dopo due diversi allenamenti motori (dopo l’utilizzo di uno strumento e dopo l’osservazione dell’utilizzo di quello strumento), lungo il continuum St. I risultati hanno mostrato l'espansione del PPS dopo l'uso dello strumento, mentre in seguito all’osservazione non è emersa alcuna espansione. Abbiamo riscontrato inoltre una maggiore espansione nel gruppo St relativamente basso rispetto a quello relativamente alto, indipendentemente dal tipo di allenamento motorio eseguito. Questi risultati sottolineano una potenziale alterazione funzionale del PPS all’aumentare del livello St. Tenendo conto dell'idea di un continuum che va dalla St alla psicosi conclamata, è ragionevole ipotizzare una minore malleabilità del PPS nella Sz. Nessuno studio ha fino ad ora indagato tale aspetto nella Sz; pertanto, questo rappresenta il focus dell'ultimo studio, che illustra i risultati preliminari sui pazienti Sz, rappresentando un altro importante contributo alla conoscenza del sé spaziale nella psicopatologia. Tutte queste evidenze arricchiscono l'attuale stato dell'arte dei disordini del sé minimale nella Sz, supportando l'idea di un sé fragile che si rompe in piccoli pezzi che includono molteplici aspetti corporei interrelati.
Anomalies of self-experiences have been associated with schizophrenia spectrum disorders. It has been proposed that the weak basic sense of self (‘minimal self’), the disturbed implicit bodily functioning and the disruption of intercorporeal attunement with others are manifestations of a disturbed bodily self in schizophrenia (Sz). This altered basic sense of self, strictly related to self-recognition and self-other discrimination impairments, have been linked to deficits in multisensory integration mechanisms. One of the basic experiences of self concerns the sense of body-ownership (BO) which is not only associated with body parts but also with the face, a crucial cue for self-identity allowing to distinguish the self from the others and in differentiating others. Sz is characterized by deficits in one’s own and others’ face recognition, as well as by a disturbed BO. Thus, the aim of the first study here presented was to integrate these lines of research investigating the Enfacement Illusion (EI) proneness in Sz. Results showed how EI induced the expected malleability of Self-Other boundary among both controls and patients; interestingly, it also demonstrated how Other-Other boundary is influenced by EI, suggesting how EI is not only confined to self-sphere but it also affects the way we discriminate others. The second study adds important new evidence in the context of the bodily self in Sz, focusing on the implicit bodily self processing, operationalized in the so-called self advantage effect (SAeff, a faster sensory motor mental rotation with self than others’ body-parts in a laterality judgment task). Results showed the absence of the SAeff in Sz revealing a specific alteration in the sensorimotor processes of self body parts, suggesting a potential distorted motor nature of the minimal self. Another crucial aspect shaping our sense of self is bodily self-awareness, the feeling of being a bodily self in space (spatial self). This experience depends on multisensory integration occurring within the portion of space surrounding our body, Peripersonal Space (PPS). PPS is not fixed, rather it dynamically shapes through motor experiences (e.g. after a tool-use). Moreover, the size of PPS largely varies across people depending on several individual characteristics, including schizotypy (St). However, little is still known about the relationship between PPS plasticity and personality traits. To this aim, we investigated PPS plasticity after two different motor trainings (i.e. after using a tool and after observing someone else using the tool), in participants along the St continuum. Results showed PPS expansion after tool-use, whereas absence of PPS expansion emerged after the observation task. Moreover, we found greater PPS expansion in the relatively-low St group than in the relatively-high one, regardless of the type of motor training performed. These results underline a potential general functional alteration of PPS with the increase of St level. Taking into account the idea of a dynamic continuum ranging from St to full-blown psychosis, it is reasonable to hypothesize a lesser malleability of PPS boundaries in Sz. No studies until now have investigated this functional aspect of PPS in Sz. Hence, this represents the focus of the last study that illustrates the preliminary results on Sz patients, constituting another relevant contribution to our understanding of the spatial self in psychopathology. Taken together, all this evidence enriches the current state of the art of the minimal self disorder in Sz, empirically supporting the idea of a fragile self, which shatters into a variety of small pieces that enclose multiple interrelated bodily aspects.

Dissertação como requisito parcial para obtenção do grau de Mestre em Segurança e Higiene no Trabalho
É vulgar ouvir-se dizer que os espaços confinados são locais potencialmente perigosos. A confirmar-se, é importante compreender o porquê da afirmação. Em análise, estará ao longo da dissertação o que se considera seguro em relação ao nível percentual de oxigénio e a comparação entre o risco percecionado e o risco real, enquadrado na temática dos espaços confinados. Com a dissertação pretendo demonstrar que os espaços confinados, só por si, só serão perigosos quando se subestimarem questões tão simples como por exemplo a avaliação e interpretação do nível de oxigénio atmosférico que deve exisitir dentro de um espaço confinado, de forma a que o mesmo seja considerado seguro. A identificação dos perigos e a avaliação dos riscos fazem parte do vocabulário geral de qualquer empresa e em particular do dia-a-dia do técnico de segurança, no entanto o que se consegue retirar da identificação dos perigos e da avaliação dos riscos dependerá em muito da perceção, do conhecimento e da experiência de quem irá realizar o trabalho de identificar e avaliar os perigos que irá encontrar, para posteriormente associar os riscos que possam estar inerentes a um determinado perigo. Fico esperançado que esta análise permita a redução de falsas garantias de segurança, as quais possam comprometer a salvaguarda das partes envolvidas, sejam gestores, chefes de equipa, trabalhadores, familiares ou amigos. Os acidentes laborais são um flagelo da atividade laboral e afetam todos os que direta ou indiretamente se relacionam com eles. Verifica-se que em muitos dos acidentes, as causas são simples e que a antecipação de uma consequência devastadora resultado de um acidente grave ou mortal, estava ao alcance de todos. Para isso não ser apenas e só um desejo das pessoas ligadas à segurança laboral, é necessário parar, pensar e acima de tudo não se assumir a presunção de princípios que, em alguns casos, estão assentes em ideologias e práticas desatualizadas.
It is usual to say and hear that confined spaces are potentially dangerous places. If confirmed, it is essential to understand the reason for that statement. It is therefore fundamental to analyse what is considered safe in relation to the percentage of oxygen, and to understand the difference between the perceived risk and the real risk. The aim of this thesis is to demonstrate that a confined space will be dangerous when underestimating such simple aspects as the assessment and the interpretation of the atmospheric oxygen level, which must exist within a confined space to be considered as safe. Hazard identification and risk assessment are part of the general vocabulary of any company, and in particular of the day-to-day work of the safety technician. However, what can be learned from hazard identification and risk assessment will depend greatly on the perception, knowledge and experience of the one who will identify and assess the hazards that are encountered, and that would be inherent to a particular hazard. It is hoped that this analysis will not allow false assurances to be given to safety, which may endanger all parties, whether they are executors, orderlies, team chiefs, managers, family members or friends. Accidents at work are a scourge of the working activity, and it affects all those that are directly or indirectly related to them. It is known that in many accidents, the causes are simple and it was within the reach of all to anticipate the devastating consequences that result from a serious or fatal accident. For this not to be only a mirage for people connected to work safety, it is necessary to stop, think and above all not to assume the presumption of principles that in some cases are based in old ideologies and practices.

L’Avranchin occupe au sein du duché de Normandie une position frontalière, partageant ses confins occidentaux avec la Bretagne, le Maine et la seigneurie de Bellême. Territoire envisagé à la fois comme interface, périphérie et interstice, c’est également un espace vécu, résultat d’une dynamique propre, animée par les sociétés qui l’habitent. À travers son rapport au pouvoir et ses ambitions locales, le groupe aristocratique, dont la formation résulte d’un processus complexe et ancien, constitue une composante essentielle de l’identité frontalière.Loin d’être une région désertique, l’Avranchin présente au IXe siècle une organisation politique et sociale dans laquelle les familles aristocratiques s’intègrent. Cette société, dont on ignore le caractère endogène ou exogène, apparaît comme le produit manifeste du regnum neustrien. Elle se révèle notamment par le prisme des anciennes circonscriptions administratives, l’action royale ou encore le rôle des évêques et des ermites. Affectées par les profondes transformations du royaume carolingien, les familles aristocratiques sont touchées par l’influence des puissants groupes familiaux des Rorgonides puis des Robertiens, dont la stratégie de domination de l’espace se fait ressentir jusque dans l’Avranchin. La poussée bretonne du milieu du IXe siècle et la domination politique des comtes de Rennes accentuent le caractère composite et multiscalaire de cette société.Lorsque les ducs de Normandie, puis les comtes de Mortain, étendent leur autorité sur l’Avranchin au cours du XIe siècle, le groupe aristocratique présente une certaine forme de continuité. La mise en place d’un espace institutionnel résulte d’une construction habile, parfois fruit d’une politique d’accommodation et de compromis, et s’appuie sur des familles extérieures au territoire ou anciennement implantées dans l’Avranchin. Celles-ci façonnent leur pouvoir autour de nouvelles logiques et de nouvelles fidélités, induites par le contrôle ducal ou comtal, la détention d’offices administratifs ou la garde de forteresses. Elles ordonnent également leurs territoires suivant leurs propres dynamiques, parfois autour d’une fondation prieurale ou d’une fortification. Réseaux de relations élargis et de vassalité, cercles familiaux ou de voisinage montrent que les horizons de cette aristocratie ne s’arrêtent pas aux limite de ses possessions, ni à celles à l’Avranchin.Bien que n’ayant jamais engendré de vastes honneurs ou de grandes entités seigneuriales, les familles aristocratiques jouent un rôle essentiel le long des frontières. Parfois en appui de l’autorité ducale, mais bien souvent suivant leurs propres intérêts et au-delà de la maîtrise politique de la frontière, elles influent grandement sur les fluctuations du pouvoir dans les espaces périphériques de l’Avranchin où leurs interventions prennent diverses formes. La fondation de l’abbaye de Savigny en 1112-1113 éclaire cette société complexe, fortement marquée par les réseaux d’influence et d’alliance, où espace vécu et géographie des pouvoirs des familles aristocratiques façonnent l’espace frontalier
Avranchin occupies a border position within the Duchy of Normandy, sharing its western borders with Brittany, Maine and the lordship of Bellême. Territory considered at the same time as interface, periphery and interstice, it is also a living space, result of it own dynamic, organized by the societies that inhabit it. Through its relationship to power and its local ambitions, the aristocratic group, whose formation is the result of a complex and ancient process, constitutes an essential component of border identity.Far from being a desert region, Avranchin presents in the ninth century a political and social organization in which aristocratic families are integrated. This society, whose endogenous or exogenous character is unknown, appears as the obvious product of the Neustrian regnum. It is revealed in particular by the prism of the former administrative districts, the royal action or the role of bishops and hermits. Affected by the profound transformations of the Carolingian kingdom, aristocratic families are affected by the influence of the powerful family groups of Rorgonids and Robertians, whose strategy of domination of space is felt even in Avranchin. The Breton thrust of the middle of the ninth century and the political domination of the counts of Rennes accentuate the composite and multiscalar character of this society.When the dukes of Normandy, then the counts of Mortain, extend their authority over Avranchin during the eleventh century, the aristocratic group presents a certain form of continuity. The establishment of an institutional space is the result of a skilful construction, sometimes the result of a policy of accommodation and compromise, and relies on families outside the territory or formerly located in Avranchin. These shape their power around new logics and new loyalties, induced by the ducal or comtal control, the holding of administrative offices or the guarding of fortresses. They also organize their territories according to their own dynamics, sometimes around a prioral foundation or a fortification. Networks of extended relations and vassalage, family or neighborhood circles show that the horizons of this aristocracy do not stop at the limits of his possessions, nor at those in Avranchin.Although they have never generate vast honors or great seigniorial entities, aristocratic families play an essential role along the borders. Sometimes in support of the ducal authority, but often according to their own interests and beyond the political control of the border, they greatly influence the fluctuations of power in the peripheral areas of Avranchin where their interventions take various forms. The founding of the abbey of Savigny in 1112-1113 sheds light on this complex society, strongly marked by networks of influence and alliance, where the living space and geography of the powers of the aristocratic families shape the border area