Faculty of Criminology, Justice and Policy Studies

This thesis is an exploration of the daily realities of childhood in the Johannesburg inner city, investigating how the children understand and negotiate the possible dangers and probable safeties of the inner city. Growing up in the inner city is an image few think is possible. However, throughout my research I will argue for a conceptualisation of childhood that speaks to the urban public spaces in the Johannesburg inner city and an inner city that speaks to the a new childhood in South Africa. I have used danger and safety negotiation as the bridge between studies of the Johannesburg inner city and studies of a South African childhood, and as a bridge in the gap between theories on childhood and theories on the city. I investigate the ways that the children negotiate the everyday dangers in the city and develop practices of safety, and how these practices and avoidance techniques speak to the reality of living in the inner city. The very nature of the congested inner city offers a freedom that many suburban childhoods lack, and that the children experience an independent mobility within an infamously dangerous space speaks to the changes within the inner city often hidden behind the skewed opinion of many of the Johannesburg inner city. I make a claim that the inner city offers more freedom of mobility that is expected. This mobility is a relatively simple and well practiced form of creating visibility within the pedestrian congestion of the city. These practises of visibility, I argue, is heavily reliant on the layout of the inner city and the ways in which children understand the dangers that face them. As such, their safety practices are a complex network of sharing cautionary stories and avoidance techniques. For most children, this environment is also the only space that they know and therefore, what to outsiders might seem a dangerous, chaotic and confusing space is to the children just their everyday experience. These are the stories about which I write.

L’interaction physique humain-robot est un domaine d’étude qui s’est vu porter beaucoup d’intérêt ces dernières années. Une optique de coopération entre les deux entités entrevoit le potentiel d’associer les forces de l’humain (comme son intelligence et son adaptabilité) à celle du robot (comme sa puissance et sa précision). Toutefois, la mise en service des applications développées reste une opération délicate tant les problèmes liés à la sécurité demeurent importants. Les robots constituent généralement de lourdes machines capables de déplacements très rapides qui peuvent blesser gravement un individu situé à proximité. Ce projet de recherche aborde le problème de sécurité en amont avec le développement d’une stratégie dite "pré-collision". Celle-ci se caractérise par la conception d’un système de planification de mouvements visant à optimiser la sécurité de l’individu lors de tâches d’interaction humain-robot dans un contexte industriel. Pour ce faire, un algorithme basé sur l’échantillonnage a été employé et adapté aux contraintes de l’application visée. Dans un premier temps, l’intégration d’une méthode exacte de détection de collision certifie que le chemin trouvé ne présente, a priori, aucun contact indésirable. Ensuite, l’évaluation de paramètres pertinents introduit notre notion de sécurité et définit un ensemble d’objectifs à optimiser. Ces critères prennent en compte la proximité par rapport aux obstacles, l’état de conscience des êtres humains inclus dans l’espace de travail ainsi que le potentiel de réaction du robot en cas d'évènement imprévu. Un système inédit de combinaison d’objectifs guide la recherche et mène à l’obtention du chemin jugé comme étant le plus sûr, pour une connaissance donnée de l’environnement. Le processus de contrôle se base sur une acquisition minimale de données environnementales (dispositif de surveillance visuelle) dans le but de nécessiter une installation matérielle qui se veut la plus simple possible. Le fonctionnement du système a été validé sur le robot industriel Baxter.

Magistro darbų kolekcijoje „Priklausomybių anatomija grafikos darbų cikle “Juoda ugnis” kalbama apie priklausomybių pavojus. Žodžiui „priklausomybė” priskiriama daugybė įvairių reikšmių. Juo yra apibūdinami žmonės, turintys liguistų polinkių. Bendras asmenų, priklausomų nuo alkoholio, narkotikų, azartinių žaidimų, sekso, maisto ir kt., bruožas yra bejėgiškumas prieš savo ligą. Bet kokią priklausomybę galima apibūdinti kaip besikartojančią elgseną, kuri trumpam sumažina nemalonią emocinią būseną ar ją susilpnina, bet ilgainiui, toks pasikartojantis elgesys kuria tą įtampą keliančią būseną. Priklausomybę sukelia ne vartojama medžiaga ar daiktas, o tokios medžiagos ar daikto vartojimas (naudojimas), siekiant emocinės pusiausvyros. Didžioji dalis žmonių kenčiame nuo vienokio ar kitokio liguisto potraukio. Grafikos darbuose pagrindiniu akcentu tampa žmogus. Kiekviename kūrinyje atsiranda užuomina apie pagrindinį priklausomybių objektą. Vaizduojamos žmogaus kūno dalys ar jų užuominos. Darbuose iškyla geometrinių formų elementai. Tai tarsi įspėjamųjų ženklų ikonos, turinčios įspėti apie tykojančius pavojus kiekvieno žmogaus aplinkoje. Kūrybiniai darbai skatina pamąstyti, pajausti. Darbai reikalauja emocinio kontakto. Darbo aktualumas sietinas su šių dienų įvairių priklausomybių apsėsta visuomene. Apie tai byloja įvairūs elgesio modeliai, kylantys sergant priklausomybe. Žmonės nesugeba susidoroti su neigiamomis emocijomis. Dažnas renkasi lengvesnį kelią ir griebiasi greitesnį... [toliau žr. visą tekstą] / In the Master works collection "Black Fire" goes about the dangers of addiction. The word "addiction" has many different meanings. It describes people who have morbid propensity. General feature of persons, who are addicted to alcohol, drugs, gambling, sex, food, etc.., is helplessness before his illness. The man becomes the main focus of graphic works. The hint about the main object dependencies appears in each piece. The human body parts or clues are represented in this work. There are elements of geometric shapes. It's like warning signs icons, which have to warn about the risk in each human environment. Often the person does not see a risk. Creative works promote to think and feel. Works require emotional contact. Work problem - addiction. Any addiction can be defined as the recurrent behavior, which temporarily reduces unpleasant emotional state or to weaken it, but eventually, this repetitive behavior create intense status. Dependence is not caused by the substance or object is used, but the use of a substance or object (usage), for emotional balance. Most of the people suffer from some kind of addiction. Topicality of the work is related to today's society obsessed with various addictions. This is proved by a variety of behaviors that arise addiction of illness. People are not able to cope with negative emotions. Often they choose the easier way and resort to a faster impact on distribution patterns of conduct. A mental balance is attempt to keep in their lives by the... [to full text]

Dust is a well-known occupational hygiene challenge and has been throughout the years, especially in the coal mining industry. The hazards arising from coal dust will differ between geographical areas due to the unique characteristics of dust from the coal mining environment. It is therefore of upmost importance to identify these qualities or characteristics of coal dust in order to understand the potential hazards it may pose. It is also important to consider the presence of nanoparticles which until recently remained neglected due to the absence of methods to study them. Aim: The aim of this study was to collect significant quantities of airborne dust through static sampling to characterise the physical, morphological as well as elemental properties of inhalable and respirable dust produced at two South African underground and two opencast coal mines. Personal exposure quantification was therefore not the primary concern in this study. Method: Static dust sampling was done at two mining areas of the two opencast and underground coal mines using four Institute of Occupational Medicine (IOM) and four cyclone samplers per area at each mine. A condensation particle counter (CPC) was also used at the opencast areas. The opencast areas included blast hole drilling, drag line and power shovel operations. The underground areas included the continuous miner and roof bolter operations. Gravimetric analyses of the cyclone and IOM samples were done as well as scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) analysis. Results: Mine A (opencast and underground) produces higher grade coal in comparison to mine B (opencast and underground). Gravimetric analysis indicated higher average inhalable (55.35 mg/m3) and respirable (2.13 mg/m3) concentrations of dust in the underground areas when compared to the opencast areas (34.73 mg/m3 and 0.33 mg/m3). Blast hole drilling operations indicated higher average inhalable and respirable dust concentrations (39.02 mg/m3 and 0.41 mg/m3) when compared to the drag line and power shovel operations (30.44 mg/m3 and 0.246 mg/m3). CPC results showed higher average concentrations of sub-micron particles at the blast hole drilling areas per cubic metre (63132 x 106) compared to the drag line and power shovel operations (38877 x 106). EDS analysis from the opencast areas indicated much higher concentrations of impurities (with lower concentrations of carbon – 33.33%) when compared to samples taken from the underground mining activities (65.41%). The EDS results from the opencast areas differed substantially. The highest concentrations of silica were found at the blast hole drilling areas. EDS results from the underground areas indicated that mine A has slightly higher concentrations of carbon (66.2%) with less impurities when compared to mine B (64.62%). The continuous miner operations showed a higher concentration of impurities when compared to the dust from the roof bolter. SEM results from the opencast areas revealed that the majority of particles are irregularly shaped and the presence of quartz and agglomerations are evident. SEM results from the underground areas were similar except that the roof bolter produced smaller sized particles when compared to the continuous miner. It also seemed that the areas with higher levels of impurities produced more sub-micron particles. Conclusions: It is possible to identify the majority of physical and elemental characteristics of coal dust by means of gravimetric analysis, particle counting, SEM and EDS. There were differences found, regarding the morphological; chemical and physical characteristics, between the different opencast and underground areas at mine A and mine B due to the type of mining activity and amount of overburden present. Silicosis, Pneumoconiosis and Chronic obstructive pulmonary disease are some of the possible health concerns. It has been seen that dust from higher grade coal mines contributed to more developed stages of these diseases. / MSc (Occupational Hygiene), North-West University, Potchefstroom Campus, 2015

Dust is a well-known occupational hygiene challenge and has been throughout the years, especially in the coal mining industry. The hazards arising from coal dust will differ between geographical areas due to the unique characteristics of dust from the coal mining environment. It is therefore of upmost importance to identify these qualities or characteristics of coal dust in order to understand the potential hazards it may pose. It is also important to consider the presence of nanoparticles which until recently remained neglected due to the absence of methods to study them. Aim: The aim of this study was to collect significant quantities of airborne dust through static sampling to characterise the physical, morphological as well as elemental properties of inhalable and respirable dust produced at two South African underground and two opencast coal mines. Personal exposure quantification was therefore not the primary concern in this study. Method: Static dust sampling was done at two mining areas of the two opencast and underground coal mines using four Institute of Occupational Medicine (IOM) and four cyclone samplers per area at each mine. A condensation particle counter (CPC) was also used at the opencast areas. The opencast areas included blast hole drilling, drag line and power shovel operations. The underground areas included the continuous miner and roof bolter operations. Gravimetric analyses of the cyclone and IOM samples were done as well as scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) analysis. Results: Mine A (opencast and underground) produces higher grade coal in comparison to mine B (opencast and underground). Gravimetric analysis indicated higher average inhalable (55.35 mg/m3) and respirable (2.13 mg/m3) concentrations of dust in the underground areas when compared to the opencast areas (34.73 mg/m3 and 0.33 mg/m3). Blast hole drilling operations indicated higher average inhalable and respirable dust concentrations (39.02 mg/m3 and 0.41 mg/m3) when compared to the drag line and power shovel operations (30.44 mg/m3 and 0.246 mg/m3). CPC results showed higher average concentrations of sub-micron particles at the blast hole drilling areas per cubic metre (63132 x 106) compared to the drag line and power shovel operations (38877 x 106). EDS analysis from the opencast areas indicated much higher concentrations of impurities (with lower concentrations of carbon – 33.33%) when compared to samples taken from the underground mining activities (65.41%). The EDS results from the opencast areas differed substantially. The highest concentrations of silica were found at the blast hole drilling areas. EDS results from the underground areas indicated that mine A has slightly higher concentrations of carbon (66.2%) with less impurities when compared to mine B (64.62%). The continuous miner operations showed a higher concentration of impurities when compared to the dust from the roof bolter. SEM results from the opencast areas revealed that the majority of particles are irregularly shaped and the presence of quartz and agglomerations are evident. SEM results from the underground areas were similar except that the roof bolter produced smaller sized particles when compared to the continuous miner. It also seemed that the areas with higher levels of impurities produced more sub-micron particles. Conclusions: It is possible to identify the majority of physical and elemental characteristics of coal dust by means of gravimetric analysis, particle counting, SEM and EDS. There were differences found, regarding the morphological; chemical and physical characteristics, between the different opencast and underground areas at mine A and mine B due to the type of mining activity and amount of overburden present. Silicosis, Pneumoconiosis and Chronic obstructive pulmonary disease are some of the possible health concerns. It has been seen that dust from higher grade coal mines contributed to more developed stages of these diseases. / MSc (Occupational Hygiene), North-West University, Potchefstroom Campus, 2015

<p>Interactive media technologies like the Internet and video games have opened new avenues of opportunity for many, yet at the same time they represent new challenges and risks, especially for young people.</p><p>In our study, eleven families were interviewed. Their perceptions, experiences and risk management are described in this paper. The children we interviewed were not high media consumers. The vast majority appeared to have a positive attitude towards the Internet, and had learned to handle common interactive media challenges and risk. Nonetheless some online behaviors which we consider risky were indeed commonly practiced. The most commonly encountered risk experienced by children in our study was exposure to undesirable content. Yet, in a group of eleven children two had been victim of cyberbullying and one had been harassed by some classmate or family member.</p><p>The most recurrent negative comments parents made about the internet or video games and children were about the danger of being contacted by strangers, as well as the excessive use of the interactive media technologies.</p><p><strong><p> </p></strong></p>

La pollution des sols correspond à une problématique récente. Au même titre que l'eau et l'air, la contamination des sols industriels constitue un risque pour la santé humaine et une menace pour la protection de l'environnement, et doit donc faire l'objet d'une réhabilitation. Toutefois la volonté politique française en la matière ne s'étant affirmée qu'à partir des années 1990, les outils de gestion des sols contaminés restent encore à développer. Pour cela une réflexion a été engagée afin de mettre au point, à partir de l'expérience acquise dans les autres pays industrialisés et à partir des connaissances actuelles, des outils méthodologiques d'aide à la gestion des sites contaminés, en particulier lors des étapes : - d'évaluation de l'état de pollution du site, notamment par la caractérisation du niveau de danger et de risque que présente un site contaminé. Pour cela nous avons développé un outil, appelé TRACES (Tool for Risk Assessment from Chemical Exposure to Soils) permettant un diagnostic progressif dans le but d'établir l'opportunité d'une réhabilitation et de déterminer les objectifs de cette réhabilitation éventuelle, - d'identification des filières de réhabilitation les plus adaptées pour le traitement des sols pollués basée sur une méthode d'analyse multicritère, ELECTRE III, permettant d'intégrer les intérêts de chaque acteur de la réhabilitation, ce qui a abouti à l'outil RACES (Remediai Alternative Classification and Evaluation System). A travers ce travail, nous avons pu mettre en évidence l'importance d'outils méthodologiques pour faciliter et accélérer la prise de décision grâce à une approche structurée, objective et transparente des sols contaminés.

Interactive media technologies like the Internet and video games have opened new avenues of opportunity for many, yet at the same time they represent new challenges and risks, especially for young people. In our study, eleven families were interviewed. Their perceptions, experiences and risk management are described in this paper. The children we interviewed were not high media consumers. The vast majority appeared to have a positive attitude towards the Internet, and had learned to handle common interactive media challenges and risk. Nonetheless some online behaviors which we consider risky were indeed commonly practiced. The most commonly encountered risk experienced by children in our study was exposure to undesirable content. Yet, in a group of eleven children two had been victim of cyberbullying and one had been harassed by some classmate or family member. The most recurrent negative comments parents made about the internet or video games and children were about the danger of being contacted by strangers, as well as the excessive use of the interactive media technologies.

L’étude du lien entre l’exposition de l’Homme aux substances chimiques, notamment via son alimentation,et sa santé est un sujet de préoccupation majeure dans notre société qui présente des challenges multiples.Nous nous sommes attelés à l’un d’entre eux par la production de données analytiques fiables relatives à la contamination des denrées alimentaires et des fluides biologiques humains. Le développement de méthodes analytiques reposant sur des technologies en rupture, à même de s’adresser aux paris de la mesure de composés chimiques émergents (e.g. les retardateurs de flamme bromés) ou historiques mais sous le prisme de la sensibilité et du haut débit (e.g. les stéroïdes, les pesticides organochlorés, les dioxines et les polychlorobiphényles) a été au cœur de ce travail. Le couplage GC/APCI/MS sur système triple quadripolaire s’est imposé au cours de nos évaluations. L’association de la chromatographie en phase gazeuse et de l’ionisation chimique à pression atmosphérique a apporté un gain en sélectivité remarquable comparée aux approches traditionnellement retenues dans le domaine et a autorisé l’exploration des ultra-traces dans des matrices biologiques complexes. Cette géométrie nous a permis d’innover en pratiquant des séparations rapides sur colonne capillaire ultra-courte de 2,5 m. La vitesse de balayage et l’excellente sensibilité de l’analyseur de masse nous ont en outre donné accès à une analyse quantitative fiable et multi-paramètres. Ce travail ouvre d’excellentes perspectives vis-à-vis de la production de données d’exposition externe et interne élargies en réponse aux défis à venir entourant la caractérisation de l’exposome Humain. / The study of the link between Human exposure tochemical substances (notably via his food the intake) and Health, is a major concern in our society and poses many challenges. We endeavoured to address one of them by producing reliable analytical data on foodstuffs and human biological fluids contamination. The development of analytical methods based on breakthrough technologies, capable of challenging theemerging (e.g. brominated flame retardants) or historical compounds measurement but through the prism of sensitivity and high throughput (e.g. steroids,organochlorine pesticides, dioxins andpolychlorobiphenyls), was at the heart of our work.Using a GC/APCI/MS with a triple quadripole systememerged as a favorable choice as our evaluations progressed. The association of gas chromatography and atmospheric pressure chemical ionisation brought in a remarkable gain in terms of selectivity, compared to the approaches traditionally selected in this field, andauthorized ultra-trace exploration in complex biologicalmatrices. This geometry allowed us to innovate by performing fast separations on an ultra-short 2.5 mcolumn. Besides, the mass analyser scan speed and high sensitivity gave us access to a reliable and multiparameters quantitative analysis. This work opens up excellent perspectives for the production of expanded external and internal exposure data to meet the future challenges surrounding Human exposome characterisation.