The biomechanical aspects related to the adaptation of fixed prostheses over implants are directly associated to treatment success. Therefore, the aim of this study was to evaluate the presence of microgaps in the union formed by the abutment and the inner connection of Cone Morse dental implant. The study was composed by two groups. The first group (n:16) used materials (dental implant and abutment) of the same manufacturer, Neodent® (Curitiba-PR, Brazil). The second group (n:16) used materials from different manufacturers, where the dental implant was Neodent® (Curitiba-PR, Brazil), and the abutment was Singular®(Parnamirim-RN, Brazil). The sets were sent to scanning electron microscope (SEM), where it was taken the measurements of microgaps formed between the implant connection and the abutment. The results obtained were submitted to statistical (Mann-Whitney-U) evaluating dispersion measurements and central tendency of values (standard and mean deviation). In group 1 the average found was 5,69μm and standard deviation (SD) was 8,46μm. Group 2 showed average of 1,24μm and SD: 0,44μm. The group formed by dental implant and abutment from the same manufacturer showed a greater data dispersion, with greater microgap values, compared to the group formed by the set implant-abutment of different manufacturers. It was concluded that, based on the measurements taken on SEM, the group formed by implant and abutment of different manufactures showed lower values of microgaps, and, therefore, a better in vitro adaptation. / Os aspectos biomecânicos relacionados à adaptação da prótese sobre o implante dentário estão diretamente associados ao sucesso do tratamento. Assim, o objetivo deste trabalho foi avaliar a presença de microgaps na união formada pelo abutment e a conexão interna do implante dentário do tipo Cone Morse. O estudo foi composto de dois grupos onde no primeiro grupo (n:16) foram utilizados materiais (implante dentário e abutment) do mesmo fabricante, Neodent® (Curitiba-PR, Brasil). No segundo grupo (n:16) foram utilizados materiais de fabricantes diferentes, sendo o implante da marca Neodent® (Curitiba-PR, Brasil) e o componente protético da marca Singular®(Parnamirim-RN, Brasil). Os conjuntos foram levados ao microscópio eletrônico de varredura (MEV), sendo realizadas as mensurações do microgap formado entre a conexão do implante e o componente protético. Os resultados obtidos foram submetidos à análise estatística (Mann-Whitne-U) avaliando-se medidas de dispersão e tendência central dos valores (desvio padrão e média). No grupo 1 a média encontrada foi de 5,69μm e o desvio padrão (DP) foi de 8,46μm. O grupo 2 apresentou média de 1,24μm e o DP: 0,44μm. O grupo formado por implante e componente protético do mesmo fabricante apresentou maior dispersão dos dados, com valores maiores para o microgap, comparando-se com o grupo formado pelo conjunto implante-abutment de marcas diferentes. Concluiu-se que, com base nas mensurações realizadas no MEV, o grupo formado por implante e abutment de diferentes fabricantes apresentou menores valores de microgap e consequentemente uma melhor adaptação in vitro.

Orientador: Regina Maria Puppin-Rontani / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-15T22:54:34Z (GMT). No. of bitstreams: 1 Pacheco_LarissaFerreira_M.pdf: 2738346 bytes, checksum: a45f65b512f358ab0bd0c6efb39313e0 (MD5) Previous issue date: 2010 / Resumo: A utilização de materiais restauradores unidos ao substrato dentinário tem sido um desafio que vem sendo superado nos últimos anos. Pesquisas têm conseguido aperfeiçoar a união dos materiais ao substrato dentinário, porém, a maioria dos estudos utiliza dentina hígida, uma vez que a utilização da dentina após remoção de cárie, isto é o substrato dentinário afetado pela cárie torna as pesquisas de difícil execução. Dentre os principais motivos destaca-se a difícil seleção de lesões similares, sendo, portanto um desafio para os pesquisadores pela variabilidade encontrada nos resultados não se alcançando a devida evidência científica para a aplicação das técnicas de união. A fim de aprimorar os estudos sobre este tipo de substrato, o objetivo deste estudo foi avaliar diferentes modelos de produção de cárie: modelo biológico e modelo in situ, comparando-os quanto a microdureza e profundidade de cárie à lesão de dentes extraídos com cárie. Foram utilizados 15 terceiros molares, compreendendo 5 dentes extraídos com cárie (cárie oclusal de profundidade média - C, grupo controle), 10 dentes eram hígidos, dos quais 5 foram utilizados para o modelo de produção de cárie in situ (IS) e 5 para o modelo biológico (MB). De todos os dentes foram obtidos blocos de dentina de 4x4x2 mm. Os blocos de dentina hígida foram analisados quanto à microdureza de superfície (SMH) e depois submetidos ao processo de cárie artificial. Após o desafio cariogênico, os blocos dos 3 grupos (C, IS, e MB) foram seccionados longitudinalmente ao centro obtendo-se dois hemi-blocos um dos quais foi submetido à análise da microdureza longitudinal (CSMH), e o outro à análise em Microscopia Eletrônica de Varredura (MEV). A microdureza longitudinal foi medida em 4 colunas com 8 pontos diferentes (com distância de 20µm entre as cinco indentações iniciais e 100µm entre as três finais), obtendo-se uma média de medidas por bloco. Os hemi-blocos restantes foram submetidos à análise em MEV para verificação da profundidade da lesão (X25 e X200), que foi medida na região mais profunda de cada uma delas. Os dados obtidos na análise da microdureza de superfície e longitudinal da lesão foram submetidos ao teste t, ANOVA e teste de Tukey, respectivamente (p<0,05). E os dados obtidos na análise de profundidade da lesão pelo MEV foram submetidos a ANOVA e teste de Tukey (p<0,05). Os resultados da microdureza de superfície após a produção de cárie mostrou que houve diferença significante entre os modelos de produção de cárie biológico e in situ, sendo que o modelo biológico não diferiu da lesão de cárie natural. Na microdureza longitudinal o modelo in situ apresentou nenhuma diferença estatística da cárie natural, mas o menor valor de CSMH foi observado na cárie produzida pelo modelo biológico. Na análise do MEV a lesão de cárie em dentina produzida pelo modelo biológico e a dentina cariada naturalmente tiveram profundidades similares, e o modelo in situ apresentou a menor profundidade de lesão de cárie. Baseado nos resultados obtidos neste estudo, foi concluido que os dois métodos de produção de cárie mostraram características similares ao da lesão de cárie natural em dentina nos diferentes testes realizados: microdureza de superfície e longitudinal, e Microscopia Eletrônica de Varredura. / Abstract: The use of restorative materials attached to the dentin substrate has been a challenge that has been overcome in the last years. Research has been able to improve the bonding between the materials and dentin substrate, however, the most studies use sound dentin, since the use of dentin after caries remove, such as dentin substrate affected make research difficult to perform. Among the main reasons stand the difficult selection of similar lesions, and, therefore a challenge to the researchers for the variability found in the results not reaching the proper scientific evidence for the application of bonding techniques. In order to improve the researches about this specific substrate, the aim of this study was to evaluate different models to produce caries, using the biological model, and the in situ model, comparing them about the cross-sectional microhardness and caries depth with the natural carious lesion, thus, extract teeth with caries dentin. Were used 15 third molars, including 5 teeth with natural caries (occlusal caries with average depth- CN), 10 teeth were sound, which 5 were used for the in situ production model of caries (IS) and 5 for the biological model (MB). Of all the teeth were obtained dentin samples with 4x4x2mm. Sound dentin samples were submitted to surface microhardness analysis and after to artificial caries process. After the cariogenic challenge, samples of the three groups (CN, IS, e MB) were cross sectioned to the center obtaining two sections which one was submitted cross-sectional microhardness analysis (CSMH) and the other to Scanning Electron Microscopy (SEM). Samples were analyzed as cross-section hardness in 4 columns with 8 different points (with a distance of 20µm between the first five indentations and 100µm between the last three) obtaining average measures for sample. The rest of sections were submitted to analysis by SEM to check the depth of the lesion, which was measured in the deepest region of each one. The data obtained by microhardness analysis and the depth lesion by SEM were submitted to ANOVA 2 criteria and t test, and ANOVA and Tukey test, respectively (p<0,05). Results of surface microhardness after to artificial caries process showed significantly difference between biological model and in situ model, and the biological model had no difference to natural caries. In the cross-sectional microhardness in situ model present no statistically difference from natural caries, but the lowest CSMH was observed for biological model of caries producing. SEM analysis, the artificial carious dentin lesions produced by biological model and natural carious dentin had similar depth, and the in situ model had the lowest depth of carious lesion. Based on the obtained results of this study it was concluded that both methods showed similar characteristics to natural caries dentin but concerning different tests: surface and cross-sectional microhardness, and scanning electron microscopy. / Mestrado / Odontopediatria / Mestre em Odontologia

Na prática clínica, a queixa de dor no joelho em pacientes, a partir da quinta década de vida, é muito freqüente e comumente atribuída à lesão meniscal degenerativa. A relação entre a lesão degenerativa do menisco e a artrose é controversa, assim como a relação do varo e a evolução para artrose do joelho. Foram estudadas as alterações macroscópicas e microscópicas dos meniscos em 21 pacientes com deformidade em varo submetidos a artroplastia total do joelho, decorrente de artrose do joelho. Analisou-se, também, a relação destas lesões com o grau de artrose e varismo dos pacientes. Foram encontrados 9 de 21 meniscos com lesões, sendo o menisco mais acometido o medial e a lesão mais freqüente em clivagem horizontal. Neste modelo clínico de artrose com joelho em varo, afirma-se que: 1) Não foi possível estabelecer correlação entre o grau de artrose e a maior ocorrência de lesões meniscais macroscópicas; 2) Não se observou relação entre a maior gravidade da deformidade angular em varo dos joelhos com o aumento da ocorrência de lesões meniscais; 3) Quando ocorreram, as lesões meniscais preponderaram no menisco medial e as mais freqüentes foram as em clivagem horizontal; 4) Os meniscos apresentaram alterações microscópicas significativas resultantes do processo de artrose dos joelhos; no entanto, não há evidência que a presença de lesões é estatisticamente diferente entre os meniscos lateral e medial / In clinical practice, the knee pain complaint by patients from the fifth life decade is very frequent and commonly assigned to degenerative meniscal injury. The relationship between degenerative meniscal injury and arthrosis is controversial, as well as the relationship between genu varum and evolution to knee arthrosis. Macroscopic and microscopic meniscal changes in 21 patients with varum deformities undergoing total knee arthroplasty secondary to knee arthrosis were also studied. The relationship between these injuries and the degree of arthrosis and varism of patients were also studied. Of 21 menisci, 9 were found to have injuries, the most affected being the medial meniscus and the most frequent was the horizontal cleavage meniscal injury. In this clinical model of arthrosis with varum knee (1) it was not possible to establish any correlation between the degree of arthrosis and the higher occurrence of macroscopic meniscal injuries; (2) no relationship was observed between higher severity of genu varum angular deformity and increase of meniscal injury occurrence; (3) meniscal injuries prevailed in the medial meniscus, horizontal cleavage meniscal injuries being the most frequent; (4) the menisci presented significant microscopic changes resulting from the knee arthrosis process; however, no evidence was found that the presence of injuries is statistically different between lateral and medial menisci

Les microscopes en champ proche sont très largement utilisés pour caractériser des propriétés physiques à l’échelle du nanomètre. Afin d’assurer la cohérence et l’exactitude des mesures dimensionnelles qu’ils retournent, ces microscopes ont besoin d’être étalonnés périodiquement. Le raccordement à la définition du mètre SI est assuré par le biais d’étalons de transfert dont les caractéristiques dimensionnelles sont étalonnées à l’aide d’un Microscope à Force Atomique métrologique (mAFM).Les travaux de thèse portent sur la contribution à la mise en place du Microscope à Force Atomique métrologique du LNE dans le but de caractériser et réduire l’incertitude de mesure. Une tête AFM passive thermiquement et spécifiquement conçue pour des applications de nanométrologie dimensionnelle a été développée et intégrée au mAFM. Elle comporte un système original pour mesurer les déflexions du levier nécessaire à la détection des forces s’exerçant à l’extrémité de la pointe. Il utilise une évolution de la méthode du levier optique qui permet de déporter les sources de chaleurs à l’extérieur de l’instrument. Pour cela, un nouveau capteur a été développé. Il est basé sur l’utilisation d’un bundle composé de 40 000 microfibres optiques structurées en quatre quadrants. Il remplace avantageusement une photodiode quatre quadrants et permet de transporter le signal lumineux jusqu’à des photodiodes placées à l’extérieur de l’instrument. Ce système a été modélisé, caractérisé et validé expérimentalement. La tête AFM ainsi développée est passive thermiquement. Sa conception repose sur la dissociation complète de la chaine métrologique, constituée en Zerodur, afin de lui conférer une excellente stabilité thermique et mécanique. Pour les mêmes raisons, le châssis de la tête qui supporte l’ensemble des composants et notamment le système de mesure des déflexions du levier est entièrement conçu en Invar. Cette tête repose sur une structure motorisée constituée de trois moteurs à reptation permettant l’approche de pointe mais également le réglage des interféromètres. Après intégration de la tête dans le mAFM, l’ensemble de l’instrument a été caractérisé afin d’établir son bilan d’incertitude. Plusieurs composantes ont ainsi été évaluées expérimentalement comme la non-linéarité et la stabilité de la mesure de position par interférométrie, les rotations parasites du scanner, les erreurs d’Abbe, les défauts de rugosité et de planéité des miroirs ainsi que les erreurs de bras mort. L’impact de chaque composante a été quantifié et listé dans le bilan d’incertitude. Ces travaux ont permis d’avoir une première estimation de l’incertitude de mesure du mAFM. / Scanning probe microscopes are very well used for characterization at the manometer scale. To ensure the measurement coherency and the accuracy of the results, those microscopes need to be periodically calibrated. It’s done thanks to reference standards whose dimensional characteristics are measured by a metrological atomic force microscope (mAFM) for example.The aim of this thesis work is the improvement of the metrological AFM of the LNE in order to reduce the measurement uncertainty. To reach this goal, a thermally passive AFM head has been developed and integrated on the instrument. It contains an original system to measure the cantilever deflexion and thus detect the force acting between the sample and the tip. This system is based on the optical beam deflection method but allow deporting the heat sources outside the instrument. To reach this goal, a new specific sensor has been developed. It is based on a four quadrant optic fibre bundle that contains 40 000 micro-fibre and which is ideal to replace the existing four quadrant photodiode and its conditioning electronic circuit with the bundle and its conditioning electronic circuit placed outside the instrument. This sensor has been modelled, and experimentally validated.The Developed AFM head which integrates the deflection measurement system is then thermally passive. Its design is based on the complete dissociation of the metrological loop and the structural loop. The metrological loop is made of Zerodur® in other to acquire an excellent mechanical and thermal stability and thus reduce the thermal dilatation. For the same reason, the AFM head support frame is fully made of Invar. The AFM head is placed on a motorized frame based on three piezo-leg motors (tripod) to make the tip/sample approach but also to set the interferometer signal quality. The interferometer signal is improved by combining the linear displacements of the three motors to generate small rotations. This allows setting the parallelism of the mirrors linked to the head with those linked to the translation stage.Once the AFM head integrated on the instrument, the assembly is characterized in order to establish the uncertainty budget. Different uncertainty components have been experimentally evaluated as for example: the interferometer non linearity, the drift of the XYZ position, the parasitic rotations of the translation stage, the Abbe error, the roughness and the flatness of the mirrors and the dead path errors. The impact of the each component has been quantified and listed in the uncertainty budget. This allowed getting a first estimation of the combined uncertainty of the instrument.

This dissertation presents an investigation on the capabilities of Near-Field Microwave Microscopy (NFMM) for the characterization of surface and subsurface materials. Subsurface characterization refers to the detection, differentiation and imaging of dielectric, and metallic features that are coated with an insulating layer. The design, simulation and modeling, and testing of a dielectric resonator (DR)-based NFMM and a coaxial transmission line resonator-based NFMM are discussed in detail in this work. Additionally, materials differentiation and imaging capabilities of each microscope are examined using several bulk samples, liquids, GaAs MMIC circuits, and gold/glass testing patterns. The 5.7 GHz DR-based NFMM uses a microwave probe that consists of a commercial gold-coated probe tip coupled to a DR through a non-resonant microstrip line. The probe is enclosed in an aluminum cavity to preserve the quality factor of the probe (Q=986) and therefore to enhance its sensitivity. The development of a lumped-element model of this DR-based probe is discussed in this work. Characteristics of this design are its high Q and the ability to resolve differences in permittivity (E’r) of insulting bulk samples and liquids as small as ∆E’r =1.75 and ∆E’r =0.04, respectively. The imaging capabilities of this design were verified using a GaAs MMIC phase shifter. It was found that a 10 um wide microstrip line is successfully resolved and that the spatial resolution of the microscope is 50 um when using a tungsten tip with an apex radius of 25 um. Additionally, measurement of the electrical resistance of an additive manufactured resistor was measured using the DR-based NFMM without the need of contacts. The percent difference between the electrical resistance measured using the DR-based NFMM and a four-point probe is 9.6%. Furthermore, the DR-based NFMM allows simultaneous imaging of topography and RF electrical conductivity of rough thick films without the need of an additional distance sensor; this ability is demonstrated for a rough CB028 thick film. The 5GHz coaxial resonator transmission line-based NFMM employs a half-wavelength coaxial transmission line resonator terminated in a sharp tungsten tip as the microwave probe. A quartz-tuning fork based distance following feedback system is integrated with the microwave probe in order for the NFMM to operate in non-contact mode. The Q of the probe is degraded by 30% (Q=55) due to the presence of the quartz tuning fork. Despite the low Q, this NFMM is able to differentiate several insulating bulk samples (3.8 < E’r < 25) even if they are coated with an insulating layer of thickness similar to the apex radius of the tungsten tip. Finally, the coaxial resonator transmission line-based NFMM is able to image subsurface permittivity distribution of a flexible polymer-composite PDMS-Ba0.55Sr0.45TiO3 49% which is coated with 10 um thick parylene-C layer. Measurements performed at a tip-sample distance of 100 nm reveal that within an area of 50 um x 50 um, the relative permittivity of the polymer-composite is not constant but varies between 6.63 and 11.78.

This paper investigates noise characteristics of detector preamplifier in electron scanning microscopes. Various preamplifiers are measured and the lowest noise level amplifier with good level of speed is used. Further measurement of individual levels of amplifier is done and proposed the most suitable way how to achieve the total amplification. By detailed measuring of amplifier structure are found all unpleasant factors that affect the image quality. On the basis of these dates amplifier hardware is adjusted, software solutions to improve image quality designed and model control implemented, which directly controls active elements of preamplifier so that noise for given amplification was the lowest and reached required amplification.

Les nanofils nitrures, de par leurs propriétés mécaniques et piézoélectriques exceptionnelles, sont des nanomatériaux très prometteurs pour la réalisation de dispositifs piézogénérateurs ultra-compacts et de haute efficacité. Les nanofils de GaN étudiés dans cette thèse sont synthétisés par épitaxie par jets moléculaires assistée par plasma. Grâce à des caractérisations employant un AFM résiscope spécialement adapté, nous démontrons le fort potentiel des nanofils de GaN dopés de type-n et dopés de type-p pour convertir une énergie mécanique en énergie électrique. Nous confirmons la corrélation entre la polarité des nanofils, leurs dopages et l'établissement du potentiel piézoélectrique dans les nanostructures. Nous étudions également la capacité de récupération de l'énergie générée par les nanofils, qui se fait au travers d'une diode Schottky de dimension nanométrique. De ce nanocontact, résulte une conduction à l'interface métal/semi-conducteur accrue et donc une meilleure collection de l'énergie piézogénérée par les nanofils de GaN. Enfin, en nous basant sur les mécanismes de piézoconversion mis en évidence, nous fabriquons un piézogénérateur intégrant un réseau de nanofils verticaux de GaN et fonctionnant sous compression. Le prototype délivre une densité de puissance de l'ordre de 12,7 mW/cm3, ce qui le place à l'état de l'art des piézogénérateurs à base de nanofils nitrures. / Nitride nanowires are a promising material for the fabrication of efficient and compact piezogenerators. Their tremendous piezoelectric and mechanical properties give them the ability to convert efficiently mechanical energy into electrical energy. The piezoelectric material studied in this thesis is GaN, synthetised as nanowires by PA-MBE. Thanks to an adapted AFM résiscope, we show the great potential of nitride nanowires for piezogeneration and the correlation between the polarity of the nanostructure, its deformation and the establishment of the piezopotential. We also study the harvesting efficiency of the nanostructures’ polarization, through a nanometric Schottky contact. Due to scale effects, this Schottky nanocontact shows a reduced barrier height and resistance, which lead to an enhanced conduction and thus to a better harvesting of the piezoelectric energy generated by the GaN nanowires. Based on the understanding of those mechanisms, we have built a piezogenerator integrating a vertical array of p-type GaN nanowires, embedded in HSQ resist and with their top connected by a Pt metallic electrode, leading to a Schottky contact. This prototype delivered a power density of about 12,7 mW.cm-3, which is the state of the art for GaN nanowires based piezogenerator.

This thesis reports on a literature survey and an investigation that was done on the Histology course for MBChB II learners at Medunsa. All aspects of the course were investigated including the present course as well as the possibility of replacing the lectures by multimedia computer presentations and a video. The multimedia computer presentations were specially developed for the study while an earlier developed video was also included into the study. Two instruments were used to gather information from the learners. Responses from a questionnaire as well as learner records were statistically evaluated. This information as well as information gathered from the literature was used to design a new proposed course in histology. A number of issues emerged from the study. The first issue is that histology is the least favourite of all the subsections of Anatomy. Learners prefer to study their histology by watching a video. The learners who watched the video more than four times did not do better than the others. Multimedia changed the attitude of the learners towards histology to some extent. Learners have a perception, which could not be proved, that if they study with the aid of multimedia their marks and their recollection will improve. Learners often left lectures before the end or did not attend. The reason that the learners indicated for this tendency was lack of concentration. Most learners want the system of lectures changed. They want some lectures to be replaced by multimedia. Most learners rate the histology lectures as good. The majority of learners do not want the histology course to be changed into a multimedia course. From the study it is clear that the microscope can be successfully replaced by an instructivist way of learning like a video or a multimedia computer presentation. It is however not ideal to replace a constructivist way of learning, like using a microscope, with a way of learning that is only instructivist, therefore it is suggested that the microscope is replaced by another constructivist way of learning. Providing groups of learners with unique images from the histology slides to be studied and annotated was suggested. It also became clear that if a computer-based histology course is to be implemented in future, learners will have to go through a transitional phase where the lectures and practicals are gradually replaced by multimedia. / Thesis (PhD (Information Science))--University of Pretoria, 2006. / Information Science / unrestricted

In most of the tribological experiments studying friction and wear behaviour, the contact interface is hidden. The present work attempts to overcome this hidden-interface problem by carrying out real-time tribological experiments inside Transmission Electron Microscope (TEM). This is achieved by developing an in situ TEM triboprobe which can carry out nanoscale indentation, sliding and reciprocating tests on an electron transparent sample inside TEM. A novel in situ TEM triboprobe is developed by characterising the individual components involved in the development. Coarse positioning of a sharp probe is achieved using inertial sliders. Fine motion of the probe is controlled using a 4-quadrant tube piezoceramic. This triboprobe is capable of carrying out high stiffness tribological experiments inside TEM. The interface is viewed at high resolutions in real time during the experiments using a movie rate CCD camera. In indentation experiments a sharp probe is brought into contact with the sample surface. During indentation of Aluminium alloy tribolayer, it has been observed that the cracks originate from subsurface and propagate to the surface causing delamination-like material removal. Indentation experiments on protruding silicon particle in Aluminium-Silicon (Al-Si) alloy shows that initial deformation is elastic. Once the load is increased, the particle starts indenting the soft aluminum matrix, and results in sinking of the particle into the aluminium matrix. Once the particle starts sinking, the increase in the displacement causes the generation of a crack and the propagation of this crack results in the fracture of the particle. The sliding experiments inside TEM allowed the direct visualization of asperity level interaction during sliding. The preliminary experimental results of nanoscale sliding experiments carried out using an AFM tip as the sample. The adhesive instability is observed as snap-in and snap-out events. The snap-out distance seems to depend on the local geometry of the contact. To simulate reciprocating wear, a sharp diamond probe is brought into contact with Al-Si alloy and reciprocated sinusoidally at 0.5Hz. At lower loads no wear is observed. However, when the normal load is increased, material starts getting removed in thin slivers, and most of the wear debris generated get swept away from the track. Some wear debris get entrapped in between the sliding surfaces; subsequently they join to form larger wear particles. The trapped particles generated during the test act like rollers and a significant increase in the stroke-length is observed accompanying the rolling action of the particle. The phenomena like agglomeration and dissociation of the wear particles has also been observed. Repeated deformation of the trapped particles leads to the formation of tiny liquid drop on some of the wear debris. The liquid consists of gallium which comes from the sample preparation technique. The interaction between the liquid droplets has been studied by carrying out liquid-bridge pulling experiments. Liquid gallium gets cooled with time during tensile pulling of the droplets. A nano-filament is formed between the droplets during pulling. After some time, the droplet gets solidified and coalescence of droplets does not take place. Further frictional heating was necessary to form the bridge again. The in situ TEM triboprobe, which allow the tribological processes to be observed dynamically under high resolutions, is a power full tool in detecting fundamental tribological interactions.

To supplement and modify the diagnosis and clinical research of B-cell Chronic Lymphocytic Leukemia (B-CLL), a new method based on cell imaging and image processing was developed and applied to the B-CLL patient samples. The fluorophore-labelled leukemia cells were clearly visualized, reflecting the positive/negative expression of the corresponding surface markers and their distribution. Computer algorithms were devised and used to analyze a large number of images. The fluorescence intensity of the labelled antibodies on a given cell directly reflects the expression of the corresponding surface markers. The morphology and size of leukemia cells were not identical even in the same patient’s sample and the size variation does not correlate with the number of surface markers. The amount of each surface marker was approximately fixed for each patient, but there were some relationships, for instance, the number of CD19 and CD38 markers were correlated to each other. The heterogeneous expression of surface markers confirmed an assumption that surface markers have their preferred membrane positions. One of the most important results is that the cell imaging and our image processing method has provided an alternative and reliable way to diagnose B-CLL and new insights in the prognosis of subtype of B-CLL.