Abstract This Thesis proposes and describes the use of optical coherence tomography (OCT) as a non-contact and non-destructive characterization technique for printed electronics. It is based on and includes the first published results of such an application of the OCT technique. Several different types of structures were studied to evaluate the feasibility of the application. The measurement data was used to define the surface topography, physical dimensions of the specimen features, and to evaluate the ability to characterize multi-layered and multi-material structures. Presented OCT measurements were done for: screen-printed conductive and insulating structures, microfluidic channels, microscopy glass and organic field effect transistors (OFET), both coated with polymer, and inkjet-printed colour filters. A novel approach to encapsulation inspection was presented. The results show that OCT could be used for full volumetric and non-destructive characterization of the 1-to-2-µm-thin protective layers used in organic and printed electronics. The measurements presented in the Thesis were done using OCT devices in time and in spectral domains. Despite the focus on studying the application of the technique, as a result of observations and limitations of the existing equipment, a new type of OCT device has been developed. A high data acquisition rate of the spectrometer-based systems (SD-OCT) was combined with a broadband supercontinuum light source, used so far mainly in the time-domain (TD-OCT), to enable the sub-micron-resolution spectral domain optical coherence tomography (SMR SD-OCT). The supercontinuum generation effects with virtually white probing light and enables not only superior resolution, but also, e.g., true-colour OCT imaging. The measurements performed on the inkjet-printed colour filters confirm that despite the absorptive properties of the materials, characterization of the few-microns-thin ink layers is possible using visible range of the electromagnetic spectrum and spectral domain OCT. The study shows the potential and versatility of OCT in the printed electronics characterization. In addition, the Thesis discusses further development of the technique, needed to fully match the challenging requirements of the on-line quality inspection. / Tiivistelmä Väitöstyössä sovelletaan optista koherenssitomografiaa (OCT) painetun elektroniikan kontaktittomaan ja kohdetta rikkomattomaan karakterisointiin. Väitöstyö pohjautuu tuloksiin, joissa OCT-tekniikkaa on hyödynnetty ensimmäistä kertaa painettavan elektroniikan rakenteen karakterisoinnissa. Tekniikan soveltuvuutta tutkittiin mittaamalla useita erilaisia näytteitä. Mitattua dataa käytettiin pinnan topografian ja näytteen dimensioiden määritykseen. Lisäksi tutkittiin tekniikan soveltuvuutta monikerrosrakenteiden ja useista eri materiaaleista koostuvien näytteiden mittaukseen. OCT-mittaukset tehtiin seuraaville näytteille; silkkipainetuille johteille ja eristeille, mikrokanaville, polymeerillä päällystetyille mikroskooppilaseille ja orgaanisista aineista valmistettu kanavatransistoreille (OFET) sekä mustesuihkutulostimella valmistetuille värisuodattimille. Orgaaniset materiaalit ja painettava elektroniikka suojataan yleensä koteloinnilla. Tässä väitöstyössä esitellään uusi menetelmä koteloinnin tarkastukseen. Tulokset osoittavat, että OCT-tekniikkaa voidaan hyödyntää 1-2 mikrometrin paksuisen eristekerroksen volumetrisen rakenteen karakterisointiin kohdetta rikkomatta. Tässä väitöstyössä tehdyt mittaukset tehtiin aika- ja spektritason OCT-laitteilla. Huolimatta siitä, että väitöskirjatutkimus keskittyi tekniikan uusiin sovelluksiin, väitöstyössä havaittiin käytettävissä olevien laitteiden puutteellisuudet, jonka vuoksi myös uusi OCT-laite kehitettiin. Spektrometriin pohjautuvan OCT-systeemin (SD-OCT) nopeus yhdistettiin laajakaistaisen supercontinuum valonlähteen kanssa, jota on käytetty aikaisemmin käytännössä vain aikatason OCT-laitteissa (TD-OCT). Laajakaistainen valonlähde mahdollistaa jopa alle mikrometrin syvyyssuuntaisen resoluution. Supercontinuum valonlähde tuottaa käytännöllisesti katsoen valkoista valoa, joka mahdollistaa sekä erinomaisen tarkkuuden, että objektin luonnollisen värin mittaamisen. Mittaustulokset värisuodattimilla osoittavat, että vaikka suodattimissa käytetyt materiaalit absorpoivat spektritason OCT:ssa hyödynnettyä näkyvän aallonpituusalueen spektriä, tekniikalla on mahdollista mitata muutamien mikrojen paksuisia värisuodatinkalvoja. Väitöstutkimus osoittaa OCT-tekniikan monipuolisuuden ja mahdollisuudet painettavan elektroniikan karakterisoinnissa. Lisäksi väitöstyö käsittelee tekniikan jatkokehitystä, jotta se voisi vastata mahdollisimman hyvin reaaliaikaisen laadunvalvonnan tarpeisiin.

Undesirable leadership behaviours such as workplace bullying, destructive or toxic leadership are reportedly on the increase with negative effects on both the well-being of employees and the organisation (Salin, 2003). Since there is limited empirical evidence regarding the relationship between destructive leadership and psychological distress, the purpose of this study was to determine whether such a relationship exists among employees in South African organisations. Furthermore, the study intended to investigate whether gender has a moderating effect on this relationship. Destructive leadership behaviour is defined as the systematic and repeated behaviour by a leader, supervisor or manager that violates the legitimate interest of the organisation by undermining and/or sabotaging the organisation's goals, tasks, resources, and effectiveness and/or the motivation, well-being or job satisfaction of his/her subordinates (Einarsen, Aasland & Skogstad, 2007). With a sample (n = 200) of South African employees, the study adopted a correlational design and used the Destructive Leadership Behaviour Scale developed by Aasland, Skogstad and Einarsen (2008) as well as the Hopkins Symptoms Checklist-45 developed by Derogatis, Lipman, Richels, Uhlenhuth and Covi (1974) to assess the relationship between destructive leadership behaviour and psychological distress as well as the moderating effect of gender. The results indicated that two of the six hypotheses were accepted. H2, there is a relationship between overall destructive leadership and psychological distress, has been accepted. Furthermore H5, there is a significant correlation between the participants’ overall destructive leadership scores and overall psychological distress, was also accepted. Finally H6, gender has a moderating effect on the relationship between participants overall destructive leadership scores and overall psychological distress scores, was rejected. / Dissertation (MCom)--University of Pretoria, 2014. / gm2014 / Human Resource Management / unrestricted

Dans le cadre du contrôle non destructif de matériaux, les scanners à rayons X sont devenus un moyen d’assurer la validité et la qualité de pièces de productions industrielles. TomoAdour, un prestataire de services privé en digitalisation 3D et tomographie industrielle à rayons X, utilise des technologies d’acquisition basées sur ce rayonnement telles qu’un scanner médical ou tomographe industriel, de manière à observer et à analyser des produits de ses clients. La nature des objets acquis (principalement de forte densité et de grandes dimensions) fait apparaître des défauts sur les images issues de ces scanners X. Il devient dès lors difficile, voire impossible, d’analyser les images produites. On notera en particulier la présence d’artefact métallique. Ce dernier est dû à la présence de matériaux très denses dans l’objet acquis et est la conséquence de la forte atténuation des rayons dans le métal et/ou de leur distorsion dans toutes les directions. Les données reconstruites sont donc souvent difficiles à interpréter directement, car ces artefacts peuvent masquer des informations importantes. De nombreuses méthodes ont été développées durant ces dernières années et la problématique de la réduction de l’artefact métallique a largement pu être étudiée, apportant bon nombre de solutions. Pourtant, les algorithmes proposés ne s’intéressent qu’aux applications médicales et ne tiennent donc pas compte des limitations physiques propres aux échantillons industriels. De plus, les méthodes proposées basent, toutes, leur traitement sur des données brutes, c’est-à-dire des données issues du scanner avant la phase de reconstruction (ensemble de radiographies ou de projections). Dans notre cas, seules les données reconstruites (tomogrammes, i.e. volume représentant l’objet) sont disponibles et il n’existe, à l’heure actuelle, aucune approche de réduction de l’artefact métallique basée sur ces reconstructions. Le but de ces travaux de recherche est donc de proposer, dans un premier temps, un outil permettant d’identifier et de quantifier l’artefact métallique dans les données reconstruites pour la correction de ces dernières. Dans un second temps, notre travail propose un ensemble d’approches adaptées à l’analyse de matériaux dans un contexte industriel [1; 2]. / In the field of non-destructive testing of materials, computed tomography became a good way to check defects in industrial piece production. TomoAdour is a private compagny specialized in 3D digitization and x-ray computed tomography, it uses medical and industrial imaging techniques to analyze materials provided by his customers. However, tomographic analysis is difficult to achieve due to the presence of high density objects (such that metal) in most produced pieces, leading to the well-known metal artifacts in reconstructed data. In X-Ray tomography, metal artifact is characterized by a local and straight hyper-signal. This observed phenomenon is due to high attenuations of the rays in the high density materials. Many different approaches have been proposed for metal artifact reduction during the last decade. However, these methods have been developed for medical application and does not take into account physical limitations specific to industrial materials. Moreover, state-of-the-art approaches start their process from the original projection data, that is to say directly from the acquired data. In our context, only reconstructed image is available due to clinical scanner usage, and there is currently no metal artifact reduction method only based on these data. The goal of this work is first to propose a tool which permit identifying and measuring metal artifact in the reconstructed data in order to correct them. Then, our work take in interest in presenting methods developed for an industrial context[1; 2].

Cette étude s'intègre dans le cadre d'un développement accru de nouvelles techniques de contrôle non destructif des matériaux magnétiques basées sur les phénomènes de couplage magnéto-mécanique. L'objectif est de promouvoir des méthodes originales de mesure des propriétésmagnétiques permettant d'évaluer quantitativement l'état thermo-métallurgico-mécanique d'un matériau par une simple identification inverse.Nous proposons dans ce document un modèle magnéto-mécanique couplé dit modèle multidomaine compatible avec la procédure de contrôle magnétique. Ce modèle analytique permet de simuler le comportement magnétique et magnétostrictif d'un matériau magnétique soumis à un chargement mécanique unidirectionnel. Il a montré une bonne adaptabilité à des états de contraintes et structures magnétiques variées. Le modèle multidomaine a pu être validé dans le cas d'un chargement élastique uniaxial et multixial par un simple recours à une contrainte équivalente magnéto-mécanique. Il a pu également intégrer les éléments nécessaires à la modélisation de l'influence de la plasticité sur l'état magnétique. La plasticité est introduite via un état de contrainteinterne caractérisant une structure hétérogène biphasée. Des corrélations intéressantes entre variables d'écrouissage macroscopiques et propriétés magnétiques ont été élaborées et l'approche a été validée sur un acier dual phases.Nous nous sommes enfin intéressées à a mise en place d'un protocole expérimental novateur assurant un suivi continuel du comportement piézomagnétique du matériau au cours d'un essai de fatigue. Cette technique permet d'estimer la limite d'endurance des matériaux magnétiques. / This study is within a recent research largely motivated by the possibility of development of new non-destructive techniques based on the magneto-mechanical coupling. Thus, the issue is to propose original magnetic methods allowing a quantitative evaluation of the thermo-metallurgicomechnical state of ferromagnetic materials by a simple inverse identification.We propose in this document a coupled magneto-mechanical modeling called multidomain modeling suitable for the non-destructive process. This model is able to simulate magnetic and magnetostrictive behaviors of materials submitted to an uniaxial mechanical loading. It exhibits an adaptability to various mechanical states and magnetic structures. Multidomain modeling provides good results in the case of elastic loading either uniaxial or multiaxial by the use of an equivalent stress. It can also integrate the key elements for modeling the effect of plasticity on the magneticbehavior. Plasticity is introduced through internal stress characterizing heterogenous biphasic structure. Interesting correlations between macroscopic hardening parameters and magnetic properties are shown and the plasticity approach is confirmed by experiments carried out on a dual phase steel.Finally, we propose an experimental protocol allowing in situ continuous investigation of the piezomagnetic behavior during fatigue test. This experimental technique permits the estimation of fatigue limit of ferromagnetic materials.

This study is an attempt to better understand the experience of self-destructive behaviour in First Nations adolescent girls by telling their stories, discussing factors that may contribute to the behaviours, and providing counselling insight. Not every Native girl experiences self-destructive behaviour, however those that do require more effective solutions to their problems. There is ample literature regarding non-Native girls and their experiences with self-destructive behaviour. This is not the case with Native girls, and this study is an attempt to fill the literature gap, and at the same time provide insight into counselling practice. Many factors may contribute to the experience of self-destructive behaviour in First Nations adolescent girls (e.g., gender, developmental stages, parenting, cultural norms and values, and discrimination). The combination of these issues compounds each other and creates the context for the experience of self-destructive behaviour specific to Native girls. This reality puts them at risk for truancy, juvenile delinquency, teen pregnancy, drug and alcohol abuse, depression, anxiety, eating disorders, self-harming, and ultimately suicide. In order to understand the circumstances or events that lead to a young Native woman's experience with self-destructive behaviour I interviewed three women using in-depth, semi structured interviews. When answering the open-ended questions I asked, the interviewees revealed a story with a beginning, middle, and end. This story reflected the different stages in their lives, childhood, adolescence, and eventually young adulthood. Analysis of the interviews through theme identification revealed common threads through each woman's life. Although each woman had unique experiences, their stories revealed many commonalties. These common themes reflect factors that counsellors should consider when counselling First Nations girls who are experiencing self-destructive behaviour. The results of the study suggest that counsellors should not isolate factors that lead to self-destructive behaviour. For example, First Nations girls experience not just racism or neglectful parenting — they experience both of the factors. The contributing factors begin early in life and compound one another as the girl's life progresses. Hopefully, this study contributes to the betterment of individual Native girls, also to the betterment of the families' and communities' health. / Education, Faculty of / Educational and Counselling Psychology, and Special Education (ECPS), Department of / Graduate

The resin anchored rock bolt is used extensively in the mining industry to stabilize the roof and prevent it from collapsing. However, there are different defects associated with a resin anchored rock bolt. Examples are partially encapsulated bolts, over-spinned bolts and corroded bolts. These defects reduce the integrity of the roof, and thereby have an effect on the safety and productivity of the mines. The integrity of the rock bolts is a critical issue for the mining industry because of its influence on the safety of mining operations. Different research groups around the world have addressed the problem of determining rock bolt integrity. The most promising technique found in the literature study was based on guided ultrasonic waves (Beard and Lowe, 2003). This study extended the previous work by Beard and Lowe (2003) using guided ultrasonic waves, to investigate damage in more realistic embedded bolts which deviate from pure cylinders. The fundamental L(0,1) mode in its lower frequency range, as suggested by Beard and Lowe was utilized. This was done through the use of finite element model simulations of various defect scenarios, which were compared to experimental measurements on bolts. Defects like loss of resin encapsulation, voids and local corrosion cracks were addressed. The time traces of the different finite element defect scenarios could be directly compared to experimental time traces which distinguish this study from the analytical approach. Some finite element modelling issues were investigated and it was found that the time step is critical if an implicit solver is used, whereas for an explicit solver the element size is critical if accurate answers are needed. Furthermore it was also apparent that the boundary of the mortar has an influence on the results. The method used in the study was to move the boundaries far enough to prevent interference. This however increases the model size and thereby the computer resources required. Axisymmetric defects were modelled using axisymmetric finite elements to reduce the problem size. These models gave results comparable to the measured bolts. Three-dimensional finite element models seemed to be promising for simulating non-axisymmetric defects. It was found that it is not possible to solve large three-dimensional models without energy absorbing boundaries. Axisymmetrical and three dimensional finite element models of a partially encapsulated bolt and a bolt with a local corrosion crack were built. It was possible to detect simulated local corrosion cracks with the finite element models. Clear reflections for the crack in the bolt could be seen. If the bolt, resin and rock are cracked, different reflections will be detected. These different reflections complicated the interpretation of the results. Once the integrity of models such as these has been established, the models could in principle be used to train neural networks for use in commercial equipment. The present study was limited to lower frequencies because of computer resource limitations. Basic principles and modelling issues could however be addressed and it may be expected that these principles could soon be extended to higher frequencies with a new generation of computers. / Dissertation (MEng)--University of Pretoria, 2009. / Mechanical and Aeronautical Engineering / unrestricted

A adoção de materiais compósitos pela indústria de petróleo e gás vem ocorrendo de forma gradual, e ainda encontra certa resistência devido à novidade de sua aplicação em projetos mecânicos do setor, e da menor confiabilidade que possuem em relação a metais. A sua implementação em maiores escalas depende também do desenvolvimento de métodos de inspeção e monitoramento de integridade estrutural. Em paralelo a isso, sistemas de varredura de tubulações baseados em ondas guiadas ultrassônicas vêm ganhando espaço devido à sua capacidade de inspecionar toda a seção de trechos extensos de uma tubulação metálica. Baseado nestas duas premissas, este trabalho tem como objetivo apresentar estudos visando o desenvolvimento de uma metodologia que seja capaz de obter as propriedades elásticas de um meio e obter as características de propagação das ondas mecânicas, cobrindo uma metodologia para obtenção das propriedades elásticas baseados em ensaios ultrassônicos, um método de otimização baseado em propriedades vibracionais e por fim, confrontando dados provenientes de modelos em elementos finitos com resultados experimentais e aproximações teóricas. Como resultados espera-se gerar informações necessárias para que possa-se compreender os mecanismo de propagação das ondas elásticas, pois é ele que permitirá a obtenção de informações a respeito dos defeitos presentes na estrutura analisada ou ainda utilizar as informações de dispersão em função da frequência e em função da direção para localização de fontes acústicas em meios ortotrópicos, sendo o conhecimento das propriedades de fase e energia das ondas em tais materiais de fundamental importância para a plena exploração do seu potencial de inspeção e monitoramento. / The adoption of new materials by the oil and gas industry has been occurring gradually and still finds some resistance due to the novelty of their application in mechanical design and their lower reliability compared to metals. The usage in large scales also depends on the development of inspection methods and structure health monitoring. In a parallel way, systems that scan pipes using mechanical guided waves have gained space because of their ability to inspect the section of large excerpts of an metallic pipe. Based on these two assumptions, this work aims to study the development of a methodology that is able to obtain the elastic properties of a medium and obtain mechanical characteristics through propagation of the stress waves in it. For this, a method to obtain elastic properties based on ultrasonic testing, a optimization method was based on vibrational properties, and comparison of to data from finite element models with experimental results and theoretical approaches were used. The results are expected to generate information needed for understand the mechanism of propagation of elastic waves, needed to obtain information about defects present in the structure or using information of angular or frequency dispersion for localizing acoustic sources in orthotropic media. As knowledge of the properties of the phase and energy waves propagation in such material are crucial for the full exploitation of inspection and monitoring.

Det här arbetet har utförts hos Sandvik SMT OFP och handlar om vidareutvecklingen av en prototypenhet som kombinerar EC- och UT-prober. Båda dessa mättekniker tillhör den överhängande gruppen som kallas oförstörande provning och är menade att felsöka material utan att inverka negativt på dem. Prototypen är tänkt att användas för att mäta skikttjocklek på compound-rör. Dessa rör består av två skikt varav ett är feritiskt kolstål, och det andra rostfritt stål. Det yttre, icke-feritiska skiktets tjocklek mäts med hjälp av EC-proben. Dettagörs genom att kalibrera proben mot ett testobjekt med kända tjocklekar mellan två av vilka en linjärisering utförs. Därefter placeras proben mot mätobjektet varpå mätningen jämförs mot linjäriseringen. Den totala tjockleken mäts med UT-proben och med dessa två mätningar blir även tjockleken av det feritiska skiktet känt. I tidigare system har EC- och UT-prober suttit separata och därmed har det funnits en risk att mätpunkterna för de två proberna har blivit osynkroniserade. Förhoppningen är att den kombinerade proben ska kunna utföra de två mätningarna samtidigt, på samma punkt för att minimera denna typ av fel. Arbetet visar att isolering av kopplingspunkter på proben kan räcka för att stabilisera EC-mätningar i vatten. Det förefaller rimligt att med mer arbete kunna driftsätta en kombinerad EC- och UT-prob samt att ett nytt instrument för hantering av EC-delen skall kunna designas. / This thesis work was conducted at Sandvik SMT OFP and deals with the further development of a prototype unit that combines EC- and UT-probes. Both of these probes associated measurement techniques belong to the greater group known as non-destructive testing and are intended to detect flaws in materials without negatively affecting them. The prototype is intended to to be used for measuring the thickness of compound tubes. These tubes consist of two layers, one of which is made of ferrous carbon steel, and the other of stainless steel. The outer, non-ferrous layers thickness will be measured with the EC-probe. This is accomplished through calibration with a well defined test object with sections of known thicknesses, between two of which a linearization is made. After calibration, the probe is placed against the object that is to be measured and the result from the EC-probe is compared to the linearization. The total thickness is measured by the UT-probe and with these two measurements the thickness of the ferrouslayer is indirectly known aswell. In earlier systems EC- and UT-probes have been separated and thus there were issues with desynchronization of measurements between the two probes.The combined probe is expected to make both types of measurements simultainiously, at the same point in order to reduce the risk of this type of error. This project shows that isolation of connections between probe and wire could suffice to stabilize EC-measurements in water. It appears reasonable to believe that with more work, Sandvik SMT OFP could use a combined EC- and UT-probe in production, and that a new instrument for handling the EC-measurements could be designed.

京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第21967号 / 農博第2357号 / 新制||農||1070(附属図書館) / 学位論文||R1||N5218(農学部図書室) / 京都大学大学院農学研究科地域環境科学専攻 / (主査)教授 近藤 直, 准教授 小川 雄一, 教授 清水 浩 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DGAM

Content: The value chain of leather is complex and originates from the animal husbandry system to meat processing, pre tanning, tanning, post tanning and product manufacturing processing. The imbibed properties of the material gained from the environmental conditions under which the animal grew to the range of human skills and processing chemicals determines how best the leather products meet the customer desires. The customer desire for feel and handle is ultimately traced back to the origin of the animal itself. Leather thus is a unique product whose properties such as visco-elasticity, breathability etc. remained unmatched by synthetics. Industrialization activities, reduced farming, the vegan culture all have contributed to reduced availability of hides and skins for meeting the quantity of leather required for various end products. This in essence contributed to the growth of a new market for synthetics, wherein the manmade fabrics tried to reproduce all the features of leather, synthetically. Commercially, these products came to be known through various names such as leatherette, faux leather, vegan leather, PU leather, pleather etc. Advancement in material science led to a range of products and manufacturing methods has today ensured that conventional identification techniques such as rough edges, imperfect surfaces, wrinkle test, water absorption, burnability, uneven stitch holes, structure retention, smell, grain pattern can no longer be used to distinguish between leather and similar artificial products. Advancement in technology for the manufacture of various types of leather like materials has made it difficult to identify genuine leather from other leather like materials. With leather like materials meeting most of the conventional methods of identifying genuine leather there is today a need for a new methodology for identifying genuine leather. This paper addresses to a study of a statistically relevant number of samples of leather and non-leather materials through a range of iterative instrumental techniques leading to the establishment of a protocol for identification of genuine leather. The methodology starts with the FTIR-ATR based (non-destructive) identification of signature bands of collagen – the amide I, II and III. After the first level screening, iterative analysis of samples that have the amide bands matching with that of collagen would be screened through techniques such as hydroxyproline estimation, thermogravimetric analysis, fibre structure assessment etc. The paper would report the results, the positives and negatives associated with the first level screening for genuine leather using FTIR. Take-Away: 1. A method for identifying genuine leather. 2. Value addition to leather by way of facile identification. 3. Customer satisfaction.