It is the purpose of this research project to develop a profile of predictive variables that would be helpful in distinguishing a missing juvenile report of a runaway from that of a missing youth who may have met with "foul play" and who does not fit the pattern of the runaway youth. The usefulness of such a tested set of predictive variables would be in designing a report form to be used by the peace officer who takes the initial report enabling him to immediately identify the situation as one of a runaway indicating one type of follow-up as opposed to a situation involving the possibility of "foul play" which would indicate a totally different investigative procedure and priority of action.

This paper analyzes the stress and coping mechanisms of lesbian homeless adolescents to identify potential buffers against homelessness. The Minority Stress Model and identity theories are used as a framework to interpret the findings in the literature. Based on the findings in the literature, it is possible to conclude that lesbian homeless youth are more susceptible to minority stress due to a lack of adaptive coping resources and social support. Increased levels of minority stress may lead to internalizing and externalizing symptoms that cause runaway and throwaway episodes in homeless youth. This paper proposes a new model to understand the internal and environmental factors that contribute to homelessness in lesbian adolescents.

Med övergången till elektrifiering inom transport uppstår nya utmaningar när det gäller batterisystem som placeras i elfordon. Det finns för närvarande en möjlighet att minska riskerna med toxiciteten hos partiklar som sprutas ut med de gaser som bildas under termisk rusning i litiumjonbattericeller som är placerade i batterisystem. Syftet med denna avhandling är att identifiera potentiella material för partikelfiltrering från dessa gaser, undersöka de valda materialens prestanda i ett experiment, och föreslå material för framtida studier. Filtermaterialet är avsett att sitta vid ventilen i batteripacket. Totalt valdes 5 filter för experimenten, där 3 av dessa var mikrofiberfilter gjorda av kvarts och 2 var mikrofiberfilter av glas. Filtren klämdes mellan stålplattor med ett hål, och placerades 40 cm ovanför battericellens ventil. Battericellerna utlöstes till termisk rusning och filtren placerades i den direkta vägen för utslungade partiklar för att testa deras termiska motstånd och partikelretentionsförmåga. Filtren karaktäriserades med hjälp av vägning, svepelektronmikroskopi, samt energidispersivt röntgenspektroskopi. Efter ett första test ansågs glasfiberfiltren inte ha tillräckligt hög värmeresistens för att fortsätta testas. Kvartsmikrofiberfiltren varierade i fråga om värmeresistens, där de ibland brann upp och ibland förblev helt intakta. Detta berodde troligtvis till stor del på skillnader i termisk rusning mellan experimenten på grund av varierande uppvärmningsparametrar. Kvalitativt sett lyckades kvartsmikrofiberfiltren fånga upp partiklar, men det kan inte kvantifieras i detta experiment hur effektiva de var när det gäller partikelretention. Filtren visade potential för en enkel tillämpning i batteripacket, men ytterligare forskning bör göras för att undersöka viktiga faktorer, såsom mottryck från filtren. Dessutom finns det vissa material som kan vara intressanta att testa i framtiden, bland annat keramiska material, sintrade metallfiberfiltar och ablativa material. / With the shift towards electrification in transportation, new challenges arise with regards to battery systems placed in electric vehicles. There is an opportunity to reduce risks associated with the toxicity of particles ejected from the gases that form during thermal runaway (TR) in lithium-ion battery cells placed in battery systems. The aim of this thesis is to identify potential materials for particle filtration from these gases, investigate the performance of the chosen materials in an experiment, and suggest materials for future studies. The filter material is intended to sit by the vent in the battery pack. In total 5 filters were chosen for the experiments, where 3 of those were quartz microfibre filters and 2 were glass microfibre filters. The filters were sandwiched between steel plates with a hole, placed 40 cm above the battery cell vent. The battery cells were triggered into thermal runaway, and the filters were placed in the direct path of ejected particles in order to test their thermal resistance and particle retention capabilities. The filters were characterized using weighing, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. From an initial test, the glass fibre filters were deemed not sufficient enough in terms of thermal resistance to continue being tested. The quartz microfibre filters varied in terms of thermal resistance, where they at times burned away and other times remained intact. This was largely attributed to differences in TRs between the experiments due to varying heating parameters. Qualitatively, the quartz microfibre filters succeeded in catching particles, but it cannot be quantified in this experiment how efficient they were in terms of particle retention. The filters showed potential in an easy application in battery packs, but further research should be done to investigate important factors, such as back pressure from the filters. Furthermore, there are certain materials that could be interesting to trial in the future. These include ceramic materials, sintered metal fibre felts, and ablative materials.

付記する学位プログラム名: 京都大学卓越大学院プログラム「先端光・電子デバイス創成学」 / 京都大学 / 新制・課程博士 / 博士(工学) / 甲第23903号 / 工博第4990号 / 新制||工||1779(附属図書館) / 京都大学大学院工学研究科電気工学専攻 / (主査)教授 雨宮 尚之, 准教授 掛谷 一弘, 講師 美舩 健, 教授 松尾 哲司 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

Text in Afrikaans / Die doel van hierdie studie was om te bepaal waarom kinders uit kinderhuise wegloop en om voorstelle ter voorkoming daarvan te maak. Ten opsigte van die fenomeen "wegloop" stateer die literatuur dat kinders wegloop vanaf onaangename omstandighede en/of wegloop na aangename omstandighede. Die belewing van gesinstres, gesinskonflik, portuurgroepdruk, utopiese voorstellings van wegloop, onaangename skoolbelewing en tiener swangerskap is aangeduide rolspelers onderliggend aan bogenoemde. Die empiriese studie na wegloop uit kinderhuise bet aan die lig gebring dat kinders uit kinderhuise wegloop weens traumatiese belewing van verwydering uit die ouerhuis, etikettering en inrigtingsversadiging. Voorts is bevind dat faktore wat onderliggend aan bogenoemde is, tot 'n groot mate voorkom kan word. Sekere aanbevelings ter voorkoming van wegloop uit kinderhuise is na aanleiding van die studie gedoen en kan gebruik word in die volwassene se bemoeienis met die kinderhuiskind. / The object of the study was to identify the reasons why children run away from children's homes and to make recommendations on how to prevent them from running away. On considering "run away" as a phenomenon, the literature states that children run away from harsh circumstances to acceptable or pleasant circumstances. Experiences such as family stress, conflict in the family, peer group pressure, romanticising the idea, harsh school experiences and teenage pregnancies are roll players subjacent to the above mentioned. The empirical study of "running away from children's homes" has confirmed that children run away because of traumatic separation from parental homes, labelling and institutional intolerance. Furthermore it was also found that factors subjacent to the above mentioned can be neutralised to a large extent. Certain guidelines have been recommended for adults when confronted with children in children's homes. / Psychology of Education / M. Ed. (Voorligting)

Dans les tokamaks, Sous l'application champ de électrique, les électrons sont accélérés et en même temps, ils subissent une force de friction due aux collisions avec les autres particules du plasma. Cependant, une fraction de la population totale d'électrons peuvent surmonter la force de friction et atteindre une vitesse proche de la vitesse lumière. Ces électrons relativistes sont découplés du plasma et sont appelés électrons runaway (ER). Ils peuvent apparaître lors des différentes phases d'une décharge de plasma. Par exemple, dans la phase de démarrage ou alors pendant les disruptions, au cours desquelles une fraction importante du courant plasma peut être convertie en ER ayant une énergie pouvant atteindre quelques dizaines de MeV. Les ER créés pendant la phase de perturbation peuvent causer des dommages aux premiers composants murs si un dépôt localisé de forte puissance se produit. ITER étant un tokamak de grande taille et un projet coûteux, la génération d'ER n'est pas souhaitable. La viabilité de la machine nécessite que les ER soient détectés en temps réel. La thèse fournit une étude détaillée dans cette direction pour le développement des deux principaux diagnostics sur ITER impliqués dans les mesures de paramètres pour les ER, à savoir, le moniteur de rayons X durs qui détecte le rayonnement de bremsstrahlung et les caméras visibles et infrarouges qui détectent le rayonnement synchrotron. Une solution de conception unique a été proposée pour le moniteur HXRM et est développée ici et optimisée. Pour les caméras, une modélisation des signaux est effectuée pour la première fois. Pour ce faire, un code de calcul a été développé et validé sur différents tokamaks. / In tokamaks, under the application of the electric field, a small fraction of the total electrons population can overcome collisional drag force and attain high velocity close to the speed of light. These relativistic electrons are called Runaway-Electrons (REs). The REs can occur during different phases of a plasma discharge. REs created during the disruptions phase can form a high energetic RE-beam that poses a risk to damage the first wall components if localized high power deposition takes place. ITER being a large size tokamak and an expensive project, generation of REs is not desirable during any phases of a plasma discharge. Detection of these REs and measurements of its parameters are important for the tokamak operation. Hence, RE diagnostics have to be in place to aid the commissioning of the disruption mitigation system and also for the post-event analysis to improve the reliability of RE avoidance. The present thesis gives a detailed study in this direction for the development of the two principal ITER Diagnostics involved in RE parameter measurements, namely the Hard X-Ray Monitor (HXRM) that detects bremsstrahlung radiation and the Visible and Infrared Cameras that detect synchrotron radiation. A unique design solution has been given for the HXRM and is developed, R&D tests were performed and optimized in line with this understanding. For the cameras, it is predicted for the first time which images and signal intensity can be expected. To achieve this, a simple but comprehensive code has been developed and validated on tokamaks that can predict RE parameters and corresponding diagnostic signals which may have further uses also in the context of RE avoidance.

Text in Afrikaans / Die doel van hierdie studie was om te bepaal waarom kinders uit kinderhuise wegloop en om voorstelle ter voorkoming daarvan te maak. Ten opsigte van die fenomeen "wegloop" stateer die literatuur dat kinders wegloop vanaf onaangename omstandighede en/of wegloop na aangename omstandighede. Die belewing van gesinstres, gesinskonflik, portuurgroepdruk, utopiese voorstellings van wegloop, onaangename skoolbelewing en tiener swangerskap is aangeduide rolspelers onderliggend aan bogenoemde. Die empiriese studie na wegloop uit kinderhuise bet aan die lig gebring dat kinders uit kinderhuise wegloop weens traumatiese belewing van verwydering uit die ouerhuis, etikettering en inrigtingsversadiging. Voorts is bevind dat faktore wat onderliggend aan bogenoemde is, tot 'n groot mate voorkom kan word. Sekere aanbevelings ter voorkoming van wegloop uit kinderhuise is na aanleiding van die studie gedoen en kan gebruik word in die volwassene se bemoeienis met die kinderhuiskind. / The object of the study was to identify the reasons why children run away from children's homes and to make recommendations on how to prevent them from running away. On considering "run away" as a phenomenon, the literature states that children run away from harsh circumstances to acceptable or pleasant circumstances. Experiences such as family stress, conflict in the family, peer group pressure, romanticising the idea, harsh school experiences and teenage pregnancies are roll players subjacent to the above mentioned. The empirical study of "running away from children's homes" has confirmed that children run away because of traumatic separation from parental homes, labelling and institutional intolerance. Furthermore it was also found that factors subjacent to the above mentioned can be neutralised to a large extent. Certain guidelines have been recommended for adults when confronted with children in children's homes. / Psychology of Education / M. Ed. (Voorligting)

In America, it is estimated that between 500,000 and two million children run away each year. A majority of these runaways become involved with illegal substance abuse. This study questions whether children experience substance abuse prior to their running away or if their substance abuse is an attempt to cope with the new stressors created by street life. Data collection will include having 50 volunteers complete a questionnaire, with consideration of race and gender. The findings suggested that no relationship exist between runaways engaging in drug use and the amount of stress experienced at home or during the runaway.

No description available.

<div>Potassium-ion batteries (PIBs) recently emerged as a next-generation energy storage technology, utilizing abundant and inexpensive potassium as the charge carrier cation. PIBs operate by an analogous mechanism to lithium-ion batteries (LIBs), with reversible potassium intercalation in anode and cathode through an inorganic salt - organic solvent electrolyte medium. Despite its larger size, potassium exhibits several electrochemical advantages over sodium, including a higher affinity for intercalation into graphitic (carbonaceous) anodes, forming a stage-one KC₈ structure in graphite for a specific capacity of 279 mAh g^-1. This thesis aims to provide a thorough foundation for PIB carbon anodes, through a comprehensive experimental approach combining electrode synthesis, advanced material characterization and electrochemical-analytical techniques.</div><div><br></div><div>Safety concerns have consistently plagued LIBs despite almost three decades of widespread commercialization. Thermal runaway of LIBs can initiate as early as 80°C from exothermic breakdown of the solid electrolyte interphase (SEI) layer that covers the carbon anode surface. The subsequent reaction of lithiated carbon with electrolyte solvent leads to cathode decomposition and oxygen release for cell gassing and combustion. This thesis investigates the thermal runaway behavior of graphite anode for PIBs via differential scanning calorimetry analysis, determining the effect of electrode material, state-of-charge, and cycling history on heat generation. Notably, the PIB system emits significantly less heat overall than for LIBs, albeit an earlier and more intense onset reaction at 100°C raises safety concerns. Strategies to mitigate this exothermic reaction are presented, including electrode binder manipulation to improve graphite particle coverage and enhance SEI layer stability.</div><div><br></div><div>To further evaluate the practicality of PIBs, the electrochemical behavior of graphite anode was investigated from 0 - 40°C operating temperature, in comparison to standard LIBs. The poor rate capability of potassium is attributed to sluggish solid-state diffusion and augmented cell impedance, where 3-electrode studies revealed dramatic polarization of the potassium metal counter electrode at low temperatures. Accelerated cell aging at elevated temperatures is attributed to SEI layer growth induced by the 61% volumetric expansion of graphite during potassiation, as well as the extreme reactivity of potassium metal. A full-cell system with a Prussian blue nanoparticle cathode and graphite anode showed enhanced rate performance at low temperatures by removing potassium metal counter electrode. These results provide valuable mechanistic insight for potassium intercalation in graphite and offer a practical evaluation of temperature dependent electrochemical performance for PIBs.</div><div><br></div><div>Supplementary research includes the exploration of carbon nanofibers electrospun from polyacrylonitrile precursor with subsequent pyrolysis as PIB anode. The design of an amorphous, low density carbon with a nanoscale one dimensional morphology enables mitigation of the 61% volumetric expansion of graphite during potassiation. Remarkable stability (2000 charge-discharge cycles) is thus achieved by preventing electrode pulverization, SEI layer growth, and impedance rise during cycling. Electrochemical analysis revealed a pseudo-capacitance mechanism, enabling rapid charging through surface storage of potassium that could be enhanced by surface functionalization via plasma oxidation treatment. Moreover, two dimensional MXene transition carbonitride sheets were explored as PIB anode with X-ray diffraction and X-ray photoelectron spectroscopy used to study structural changes during potassium insertion.</div><div><br></div><div>Finally, the effect of particle morphology was investigated for LIB carbon anodes, wherein commercial graphite is compared with synthesized spherical and spiky carbons. Intercalation dynamics, side reaction rates (e.g. SEI growth), self-heating, and thermal runaway behavior were studied through a combination of electrochemical analysis and modeling by a finite volume method. Spherical particles outperform irregular commercial graphite by eliminating unstructured inhomogeneities that lead to non-uniform current distributions. Interestingly, spiky particles offer a nontrivial response, where the ordered irregularities enhance intercalation dynamics to prevent degradation at extreme operating conditions. These findings emphasize the importance of tailoring particle morphology and structure in promoting desired LIB behavior and suppressing unwanted problems.</div>