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This thesis investigates two methods of optical analysis of multiphase fluids. These two methods are nephelometry and the statistical analysis of scattered light intensity fluctuations. Nephelometry is an established technique for investigating particulate suspensions. In this work the basic technique is combined with neural network processing to develop a system capable of automatically distinguishing and quantifYing different suspensions, in particular suspensions of oil. Evidence obtained in this study suggests that neural networks can distinguish the light scattering from suspensions of different size distributions and produce a more accurate estimate of volume fraction than commonly used turbidity measurements. Non-Gaussian, fluctuating light intensities arise from the scattering of light from a varying population of suspended particles. Successful measurement of these intensity fluctuations makes feasible new instrumentation based on the statistical behaviour of the detected signal. Analyses that could prove possible include particle number, size, type and flow characteristics. Photon counting methods have traditionally been used to measure fluctuations from random media but the lower cost of analogue pin diodes makes them the preferred choice of detector if they can be applied usefully. A method of quantifYing the effect of noise from the diode detectors and removing it from the statistics of the fluctuations is developed from a model of the pin diode detectors. Experimental results show that detector noise can be compensated for in the analysis of scattered light fluctuations. Results also indicate that the model used to describe the scattering process is valid and that further work can lead to a practical instrument for the study of suspensions.

This study investigates the effects of a split injection strategy on combustion performance and exhaust emissions in a high speed direct injection optical diesel engine. The investigation is focused on the effects of injection timing, quantity, and the dwell angle between the injections using commercially available diesel fuel. Three different split injection strategies including 50:50, 30:70, and 70:30 have been investigated. Additionally, the effect of total injected fuel quantity using total fuel quantities of 10 mm3 and 20 mm3 has been investigated. Moreover, the effect of variable and fixed dwell angle in split injections has been examined for five different values between 5o CA and 25o CA in the case of variable and 10o CA for the fixed dwell timing. The last parameter investigated was the injection timing, nine injection timings have been tested for each of the strategies. A Ricardo Hydra single cylinder optical engine running at 1500 rpm was used in this investigation. Conventional methods such as direct in-cylinder pressure measurements and heat release rate analysis have been employed. In addition, optical techniques such as high speed video imaging and two-colour have been applied, aimed at in depth analysis of the effects of the aforementioned parameters on engine performance and emissions. Furthermore, a significant amount of effort was devoted to the development and application of the Laser Induced Excipex Fluorescence (LIEF) technique so that simultaneous fuel liquid and fuel vapour distribution could be visualised. This investigation concludes that split injection strategies have the potential to reduce diesel exhaust emissions while maintaining a good level of fuel economy, provided that injection timings and the dwell angle between injections are appropriately selected. Further investigations are required in order to examine the effect of split injection under different engine operating conditions and speeds. In addition, the effect of alternative fuels must be considered. Moreover, the application of LIEF technique for quantitative fuel vapour concentration measurement should be considered through further optimisation of the LIEF system and careful calibration experiments.

A incidência de câncer tem aumentado nas últimas décadas, o que coloca essa doença como um problema de saúde pública mundial. Para melhorar o prognóstico do paciente, é necessário o desenvolvimento e/ou aprimoramento de técnicas que aumentem a efetividade e diminuam os efeitos adversos do tratamento. Entre as técnicas para tratamento local de lesões neoplásicas, destacam-se a terapia fotodinâmica (TFD) e a radioterapia (RT). A TFD consiste na interação entre fotossensibilizador, luz e oxigênio molecular; que combinados causam morte celular. A RT, por sua vez, é uma técnica já consagrada clinicamente que utiliza radiação ionizante para o tratamento de tumores malignos. O efeito da combinação entre as técnicas não está claramente estabelecido, e poderia aumentar o dano causado ao tecido enquanto diminui os efeitos colaterais provenientes da RT. Neste contexto, o objetivo deste estudo é analisar os efeitos da TFD associada à RT quando comparados aos efeitos individuais de cada terapia, avaliando se existe um método preferencial de combinação das técnicas. A primeira etapa do estudo foi realizada na Universidade de São Paulo e tratou a pele sadia de ratos Wistar com diferentes protocolos que combinavam as técnicas em diversos protocolos. Análises clínicas, imunohistoquímica e histológica, além da coleta de espectros de fluorescência, foram realizadas com o intuito de observar a possível sinergia dos efeitos das terapias combinadas. Os resultados mostraram uma maior necrose tecidual para a combinação TFD+24h+RT. A combinação RT+24h+TFD não apresentou um dano tão expressivo quanto o grupo TFD+24h+RT, devido a ineficiência de produção de PpIX em tecido previamente irradiado, comprovado pelo espectro de fluorescência. Na segunda etapa, realizada no Dartmouth College, os grupos que apresentaram maior dano foram escolhidos para avaliação do dano vascular por análises de refletância, da qual foram extraídas informações sobre a saturação de oxigênio, concentrações de meta-hemoglobina e bilirrubina, fração de volume sanguíneo e raio do vaso, tanto em tecido sadio de ratos Wistar quanto em tumores cutâneos em camundongos Nude. O recrescimento dos tumores também foi avaliado. A análise óptica se mostrou um método efetivo para monitorar o dano causado pela TFD na pele normal, mas ineficiente para monitorar o dano na combinação dos grupos, uma vez que a RT não apresenta dano vascular importante. Para os tumores, as análises ópticas não foram eficazes para monitorar o dano das terapias A curva de crescimento do tumor mostrou que o grupo TFD+24h+RT foi a melhor combinação para TFD e RT. Estudar a combinação do uso de raios-X com o efeito fotodinâmico é muito importante para o entendimento de fatores associados ao tratamento de tumores malignos. Os resultados obtidos devem contribuir na escolha da melhor combinação entre os tratamentos, potencializando o resultado do tratamento de lesões, diminuindo o tempo de tratamento e os efeitos colaterais. / The cancer incidence has shown a great increase recently, making this disease a worldwide public health problem. Improving a patient\'s prognosis requires development and/or improvement of techniques that increase efficacy and reduce side effects of the treatment. Among the techniques for non-systemic treatment of cancer, photodynamic therapy (PDT) and radiotherapy stand out. PDT consists in an interaction between photosensitizer, light and molecular oxygen to induce cell death, whereas radiotherapy is a well-established technique which uses ionizing radiation for tumor treatment. The effect of the technique combination is not clear and is expected to increase the damage in the tissue while decreasing the side effects from RT. In this context, the aim of this study is to analyze the effects of PDT associated with RT compared to individual effects of each therapy, assessing whether there is a preferred method of combination of both. The first stage of the study was conducted at the University of Sao Paulo and treated healthy skin of Wistar rats with different protocols that combined the techniques in various protocols. Clinical, immunohistochemistry and histological evaluations, as well as collecting fluorescence spectra were conducted in order to observe the possible synergistic effects of combined therapies. The results showed greater tissue necrosis for combining PDT+24h+RT. The combination RT+24h+PDT did not show as significant damage as the PDT+24h+RT group, due to PpIX production inefficiency in previously irradiated tissue, evidenced by fluorescence spectrum. In a second stage, performed at Dartmouth College, vascular damage was evaluated for the groups that showed enhanced damage through reflectance analysis, which provided information about oxygen saturation, met-hemoglobin and bilirubin concentrations, blood volume fraction and vessel radius, both in healthy tissue of Wistar rats and skin tumors in Nude mice. The regrowth of tumors was also evaluated. The optical analysis proved to be an effective method to monitor the damage caused by PDT in normal skin. This is not, however, an efficient method for monitoring the damage on the combination of groups, since the RT does not present any significant vascular damage. For tumors, the optical analysis did not show an effective method to monitor the damage of therapies. Tumor regrowth curves showed that the PDT+24h+RT group was the best combination for PDT and RT. The study of combination using X-rays and the photodynamic effect is very important to understand factors associated with the treatment of malignant tumors. The results should help in choosing the best combination of treatments and may be used to enhance the result of a lesion treatment, reducing treatment time and side effects.

A incidência de câncer tem aumentado nas últimas décadas, o que coloca essa doença como um problema de saúde pública mundial. Para melhorar o prognóstico do paciente, é necessário o desenvolvimento e/ou aprimoramento de técnicas que aumentem a efetividade e diminuam os efeitos adversos do tratamento. Entre as técnicas para tratamento local de lesões neoplásicas, destacam-se a terapia fotodinâmica (TFD) e a radioterapia (RT). A TFD consiste na interação entre fotossensibilizador, luz e oxigênio molecular; que combinados causam morte celular. A RT, por sua vez, é uma técnica já consagrada clinicamente que utiliza radiação ionizante para o tratamento de tumores malignos. O efeito da combinação entre as técnicas não está claramente estabelecido, e poderia aumentar o dano causado ao tecido enquanto diminui os efeitos colaterais provenientes da RT. Neste contexto, o objetivo deste estudo é analisar os efeitos da TFD associada à RT quando comparados aos efeitos individuais de cada terapia, avaliando se existe um método preferencial de combinação das técnicas. A primeira etapa do estudo foi realizada na Universidade de São Paulo e tratou a pele sadia de ratos Wistar com diferentes protocolos que combinavam as técnicas em diversos protocolos. Análises clínicas, imunohistoquímica e histológica, além da coleta de espectros de fluorescência, foram realizadas com o intuito de observar a possível sinergia dos efeitos das terapias combinadas. Os resultados mostraram uma maior necrose tecidual para a combinação TFD+24h+RT. A combinação RT+24h+TFD não apresentou um dano tão expressivo quanto o grupo TFD+24h+RT, devido a ineficiência de produção de PpIX em tecido previamente irradiado, comprovado pelo espectro de fluorescência. Na segunda etapa, realizada no Dartmouth College, os grupos que apresentaram maior dano foram escolhidos para avaliação do dano vascular por análises de refletância, da qual foram extraídas informações sobre a saturação de oxigênio, concentrações de meta-hemoglobina e bilirrubina, fração de volume sanguíneo e raio do vaso, tanto em tecido sadio de ratos Wistar quanto em tumores cutâneos em camundongos Nude. O recrescimento dos tumores também foi avaliado. A análise óptica se mostrou um método efetivo para monitorar o dano causado pela TFD na pele normal, mas ineficiente para monitorar o dano na combinação dos grupos, uma vez que a RT não apresenta dano vascular importante. Para os tumores, as análises ópticas não foram eficazes para monitorar o dano das terapias A curva de crescimento do tumor mostrou que o grupo TFD+24h+RT foi a melhor combinação para TFD e RT. Estudar a combinação do uso de raios-X com o efeito fotodinâmico é muito importante para o entendimento de fatores associados ao tratamento de tumores malignos. Os resultados obtidos devem contribuir na escolha da melhor combinação entre os tratamentos, potencializando o resultado do tratamento de lesões, diminuindo o tempo de tratamento e os efeitos colaterais. / The cancer incidence has shown a great increase recently, making this disease a worldwide public health problem. Improving a patient\'s prognosis requires development and/or improvement of techniques that increase efficacy and reduce side effects of the treatment. Among the techniques for non-systemic treatment of cancer, photodynamic therapy (PDT) and radiotherapy stand out. PDT consists in an interaction between photosensitizer, light and molecular oxygen to induce cell death, whereas radiotherapy is a well-established technique which uses ionizing radiation for tumor treatment. The effect of the technique combination is not clear and is expected to increase the damage in the tissue while decreasing the side effects from RT. In this context, the aim of this study is to analyze the effects of PDT associated with RT compared to individual effects of each therapy, assessing whether there is a preferred method of combination of both. The first stage of the study was conducted at the University of Sao Paulo and treated healthy skin of Wistar rats with different protocols that combined the techniques in various protocols. Clinical, immunohistochemistry and histological evaluations, as well as collecting fluorescence spectra were conducted in order to observe the possible synergistic effects of combined therapies. The results showed greater tissue necrosis for combining PDT+24h+RT. The combination RT+24h+PDT did not show as significant damage as the PDT+24h+RT group, due to PpIX production inefficiency in previously irradiated tissue, evidenced by fluorescence spectrum. In a second stage, performed at Dartmouth College, vascular damage was evaluated for the groups that showed enhanced damage through reflectance analysis, which provided information about oxygen saturation, met-hemoglobin and bilirubin concentrations, blood volume fraction and vessel radius, both in healthy tissue of Wistar rats and skin tumors in Nude mice. The regrowth of tumors was also evaluated. The optical analysis proved to be an effective method to monitor the damage caused by PDT in normal skin. This is not, however, an efficient method for monitoring the damage on the combination of groups, since the RT does not present any significant vascular damage. For tumors, the optical analysis did not show an effective method to monitor the damage of therapies. Tumor regrowth curves showed that the PDT+24h+RT group was the best combination for PDT and RT. The study of combination using X-rays and the photodynamic effect is very important to understand factors associated with the treatment of malignant tumors. The results should help in choosing the best combination of treatments and may be used to enhance the result of a lesion treatment, reducing treatment time and side effects.

Exposure to diesel engine exhaust is linked to chronic and acute illness. In underground mines, workers can be exposed to high concentrations for extended periods of time. Therefore, Mine Safety and Health Administration (MSHA) enforces personal exposure and engine emission limits. These regulations target just the solid portion of diesel exhaust, known as diesel particulate matter (DPM). The majority of DPM mass is attributed to particulate organic carbon (POC) and elemental carbon (EC). Total carbon (TC) is the sum of POC and EC and currently used as the surrogate to represent DPM as a whole. The NIOSH Method 5040 is the standard sample collection and analysis procedure. It outlines collection of submicron particulate matter samples on a quartz filter then measurement of POC and EC using a thermal-optical analysis. Error in DPM measurement occurs when volatile organic carbon (VOC) sorbs onto the particulate matter deposit and filter resulting in a positive sampling artifact. To correct for this, a dynamic blank method with two quartz filters (i.e., primary and secondary) in tandem is used. However, the accuracy of the dynamic blank correction method is dependent on equal sorption of VOC onto each filter. Observed instances of higher VOC on the secondary filter result in underestimated POC measurements and in some cases negative POC. The work presented in this thesis investigates the sources of VOC interference in particulate matter sampling and possible solutions. Three existing datasets containing information from blank samples and laboratory and field DPM samples were analyzed to look into instances of higher VOC sorption onto the secondary filter. Negative total POC results were limited to blank samples, but negative results for the POC of individual isotherms were observed in blank and DPM samples. A follow-up study looked into the possibility of sampling materials as a source of VOC that preferentially sorbs onto the secondary filter. Blank samples were assembled to test five sampling materials (i.e., two types of sample cassette, cellulose support pads, impactor cassettes, and impactors). In addition, sample storage conditions (i.e., temperature and duration) were tested for their impact on VOC sorption. It was discovered that all of the sample materials tested contributed VOC and, as expected, higher storage temperatures and longer storage durations increase the amount of VOC. Preferential sorption onto the secondary filter was observed in most conditions as well. A field study explored thermal separation of VOC and POC as a possible alternative to the dynamic blank correction method. Two sets of DPM samples were collected from two locations in an underground stone mine and one set of ambient particulate matter samples was collected from a highly trafficked truck stop. The temperature of 175°C was used for this preliminary investigation. The effectiveness of a temperature separation may depend on sample location. To better understand VOC and POC evolution characteristic, further testing with a wide range of sample mass and composition as well as different temperatures is suggested. It seems unlikely that a correction method using a separation temperature would be more effective than the standard dynamic blank in occupational DPM monitoring. The work presented in this thesis highlights the difficulty in accurately measuring POC. / Master of Science / Diesel Particulate matter (DPM) is the solid portion of diesel exhaust and can cause chronic and acute illness. Underground miners can regularly be exposed to high concentrations of DPM over long periods of time, therefore DPM must be monitored. Total Carbon (TC) is the sum of particulate organic and elemental carbon (POC and EC) and is used as the surrogate measurement to represent DPM. The standard method of DPM sample analysis is subject to volatile organic carbon (VOC) interference, therefore a dynamic blank correction is used. However, in some cases, the dynamic blank over- or under-corrects. This thesis presents studies to better understand the source(s) of VOC interference and possible solutions. Three existing datasets containing information from blank samples and laboratory and field DPM samples were investigated for instances of VOC interference resulting in an overcorrection. Such instances were limited to blank and low mass samples. A field study looked into the possibility of sampling materials as a source of VOC that may cause overcorrection when using the dynamic blank method. Blank samples were assembled to test five sampling materials as well as various sample storage conditions. It was discovered that all of the sample materials tested contributed VOC and, as expected, higher storage temperatures and longer storage durations increase the amount of VOC. A second field study explored thermal separation of VOC and POC as a possible alternative to the dynamic blank correction method. Two sets of DPM samples were collected from two locations in an underground stone mine and one set of ambient particulate matter samples was collected from a highly trafficked truck stop. The temperature of 175°C was used for this preliminary investigation. Results indicate that the effectiveness of temperature separation may depend on sample concentration and composition. To better understand VOC and POC evolution characteristic, further testing with a wide range of sample mass and composition, as well as, different temperatures is suggested. The work presented in this thesis highlights the difficulty in accurately measuring POC.

L'objectif de cette thèse est d'évaluer les performances d'une méthode d'imagerie optique non-invasive pour la détection de précancers et cancers précoces de la vessie, à l'aide d'une analyse de lumière laser rétro-diffusée. L'analyse de la distribution spatiale de la lumière à la surface de fantômes multi-couches imitant l'épithelium de vessie avec différentes propriétés d'absorption et de diffusion nous a permis de montrer les modifications de ces propriétés optiques entraînent des changements de la taille de la surface du spot de lumière rétro-diffusée, mesurables par une caméra vidéo. La méthode développée est également sensible à l'accumulation d'un photosensibilisateur et est applicable aussi bien pour des études en réflectance diffuse qu'en fluorescence induite. Les paramètres optiques des fantômes synthétiques tri-couches imitant différents états des épithéliums de vessie ont été calculés à partir de la théorie des ondes électromagnétiques appliquée aux diffuseurs sphériques sans et avec une couche. Ces paramètres ont servi comme entrées aux simulations de Monte Carlo qui ont permis d'obtenir les matrices des distributions d'intensité de réflectance diffuse. Notre étude démontre que les mesures en imagerie de réflectance diffuse non-polarisée permettent de fournir des informations utiles au diagnostic tissulaire / The present thesis aimed to evaluate the performance of non-invasive optical method for bladder pre- and early- cancer detection by means of diffuse-reflected laser light analysis. The analysis of light distribution at the surface of multi-layered bladder phantoms with different scattering and absorption properties showed that the changes in the optical properties lead to increase or decrease of the diffuse-reflected light spot area, detectable by a video camera. It was also determined, that the presented method is capable of detection of the photosensitizer accumulation, and can be applied for both (diffuse-reflected laser and fluorescence) studies simultaneously. The calculations for spherical and ?coated?-spherical tissue scatterers, based on the electromagnetic wave theory, allowed for obtaining optical parameters of three-layered biological phantoms and of bladder tissues at different states. These parameters served as inputs for Monte Carlo simulations, which provided us with matrices of diffuse-reflected light distributions. The study showed that the measurements of non-polarized back-scattered laser light can provide useful information on the tissue state

<div> <div> <div> <p>Transparent alumina is a candidate material for ballistic applications where visible or infrared wavelength transmission is required. However, the transparency of polycrystalline alumina can be limited due to the rhombohedral crystal structure being inherently birefringent. Birefringence causes light scattering at grain boundaries and is detrimental to the transparency. It has been shown experimentally that the application of a high magnetic field during processing can lead to crystallographic alignment and the reduction of birefringent light scattering. This alignment method is effective but is limited in terms of scalability. This research addresses these limitations through the use of simple and cost-effective shear and elongational forming processes such as uniaxial warm pressing and direct ink writing (DIW) for the improvement of final sintered transparency. To further support the improvement of these processes as alternatives and to evaluate the possibility of using powder ratios to improve the alignment, this research will also investigate the sintering behavior during hot-pressing of equiaxed and platelet powders. </p> <p>Platelet ceramic-filled thermoplastic blends were developed and formed into sheets through uniaxial warm pressing. The solids loading (30 – 40 vol.%) and platelet diameter (1.2 and 11μm) were varied to compare effects on viscosity, percent reduction, and final alignment. All ceramic- filled thermoplastic polymer blends exhibited pseudoplastic behavior. Crystallographic alignment of green body samples was quantified by the orientation parameter (r) and grain misalignment angle (full width at half maximum, FWHM) obtained from rocking curve analysis. Blends with 11μm diameter platelets displayed a higher temperature sensitivity constant, better flow properties, and higher alignment compared to blends with 1.2μm diameter platelets. Optimal samples produced with blends containing 30 vol.% of 11μm diameter platelets demonstrated an alignment of r = 0.251 +/- 0.017; FWHM = 11.16° +/- 1.16°. A sample with optimal alignment was hot-pressed to transparency and obtained an in-line transmission of 70.0% at 645nm. The final alignment of this pre-aligned hot-pressed sample (r = 0.254 +/- 0.008; FWHM = 11.38° +/- 0.54°) improved when compared to a non-pre-aligned sample (r = 0.283 +/- 0.005; FWHM = 13.40° +/- 0.38°).</p><p>Additionally, the use of direct ink writing, an additive manufacturing technique, as a viable alignment process for producing transparent alumina was investigated. Highly loaded (> 54 vol.%) equiaxed alumina suspensions were developed with platelet additions ranging from 0-20vol.% of the total solids loading. An increase in the amount of platelet powders from 5-20vol.% increased the dynamic yield stress from 104Pa to 169Pa and decreased in the equilibrium storage modulus from 17,036Pa to 13,816Pa. It was found that the DIW process significantly increased the alignment in one orientation when compared to samples cast from the same suspensions and this behavior may be connected to the rheological properties. Lastly, an optical analysis showed that sample developed with 5vol.% platelet suspensions had higher in-line transmission values across the visible spectrum when compared to samples developed with 20vol.% suspensions. A sample cast from a 5vol.% platelet suspensions had the lowest grain alignment but possessed an in-line transmission of 42.8% at 645nm, which was the highest of the samples produced in this study. An optical loss analysis showed, that this sample has the lowest backwards scattering losses due to residual porosity and this result was supported by the density data. It is suggested that the alignment of the DIW samples is more complex and a more advanced texture analysis will need to be conducted to properly characterize the grain alignment.</p><p>Lastly, the densification behavior of equiaxed and platelet powder ratios with no intentional pre-alignment was investigated. An initial sintering investigation identified the optimum maximum pressure selected for the hot-pressing process as 20MPa. Under the selected hot- pressing parameters, the effects of 0, 25, 50, 75, and 100wt.% equiaxed powder additions on the sintering behavior, optical properties, and grain alignment was investigated. The data showed that an increase in the amount of equiaxed powders decreased the initial powder compact displacements rate. Additionally, an increase in the wt.% equiaxed powders from 0wt% to 75wt% decreases the in-line transmission from 70.9% to 40.2%, respectively at 645nm. Lastly, an increase in the wt.% equiaxed powders from 0wt% to 75wt decreased the alignment from (r = 0.321 +/- 0.005; FWHM = 16.26° +/- 0.40°) to (r = 0.509 +/- 0.022; FWHM = 34.63° +/- 2.61°), respectively.</p></div></div></div>

The quantitative measurement of structural alterations at the nanoscale level is important for understanding the physical states of weakly disordered optical mediums such as cells/tissues. Progress in certain diseases, such as cancer or abnormalities in the brain, is associated with the nanoscale structural alterations at basic building blocks of the cells/tissues. Elastic light scattering, especially at visible wavelengths range provides non-invasive ways to probe the cells/tissues up to nanoscale level. Therefore, a mesoscopic physics-based open light scattering technique with added finer focusing, partial wave spectroscopy (PWS), is developed to probe nanoscale changes. Then, molecular-specific light localization technique, a close scattering approach called inverse participation ratio (IPR) is proposed that is sensitive to nano to microstructural cell/tissue alterations. In this dissertation, we have introduced the further engineered PWS system with the finer focus for precise volume scattering and molecular-specific light localization IPR techniques. As an application of PWS, we first probe precise scattering volume in commercially available tissue microarrays (TMA) tissue samples to standardize the existing cancer diagnostic methods by distinguishing the cancer stages. We also apply the PWS technique to probe chemotherapy drug-treated metastasizing cancer patients by xenografting prostate cancer cells using a mouse model and identify drug-sensitive and drug-resistance treatment cases. On the other hand, as an illustration of another mesoscopic physics-based molecular specific light localization technique, Confocal-IPR, we study the effects of a probiotic on chronic alcoholic mice brains by targeting the molecular specific alteration in glial cells, astrocytes and microglia, and chromatin of the brain cells through staining with appropriate dyes/proteins. Using structural disorder of IPR as a biomarker, the results show that probiotics in the presence of alcohol are beneficial and help overall brain health. Finally, a TEM-IPR study was performed using nanoscale resolution TEM imaging to support the optical IPR method by studying the anti-cancerous drug effect in ovarian cancer cells. The result shows that we can quantitatively measure the effect of anti-cancerous drugs in cancer treatment and the level of tumorigenicity far below the diffraction limit, and it has a similar effect and supports the optical IPR method.

This thesis work was conducted at Luleå University of Technology in collaboration with Sandvik Rock Tools. The aim of the work was to determine the influence of carbon content on the wear performance in carburized steel in the dry contact interface of threaded connections between drill rods. In order to investigate this, samples of drill rod steel were carburized to three different carbon concentrations and shot peened to replicate the production process of a drill rod. The samples were wear tested by utilizing a twin-disc wear tester with one disc rotating at 100 RPM and the other at 3000 RPM to mimic the operating conditions in the threaded connection between drill rods. The results was evaluated by wear rate, surface topography, hardness as well as optical analysis by light optical microscopy and scanning electron microscopy. The results show that an increased surface carbon content provide a decrease in wear rate and an increase in hardness in the surface layer that undergo microstructural changes due to the frictional heat and contact pressure during wear testing. The primary wear mechanisms were identified as plastic deformation, adhesive scratching and material removal through delamination.