Die vorliegende Arbeit quantifiziert die Korrelationen zwischen blutrheologischen Parametern und Erythrozyten-Indizes an einem repräsentativen und gut definierten Kollektiv gesunder Frauen im Vorfeld eines elektiven gynäkologischen Eingriffes. Gemäß der erhobenen Resultate besteht bei 286 gesunden Frauen mittleren Alters zwischen der Verformbarkeit, dem MCV und dem MCH der Erythrozyten eine statistisch signifikante Korrelation, die in Gegenwart hoher Scherkräfte an Ausprägung zunimmt. Gleichzeitig vermindert sich mit zunehmender MCHC die Erythrozytenverformbarkeit stetig und statistisch signifikant, wobei dieser Effekt am deutlichsten in Gegenwart hoher Scherkräfte, wie diese beispielsweise in den Kapillaren der Endstrombahn anzunehmen sind, nachweisbar ist. / The physiological association between blood rheological parameters and red blood cell indices was investigated in otherwise healthy unselected women prior to elective gynaecological surgery. In a total of 286 healthy women was the RBCdeformability statically significantly positive correlated with MCV and MCH but statically significantly inversely correlated with MCHC. The correlation between RBC Indices and RBC deformability was most remarkable during moderate shear force exposure.

To reduce cost of structural composites the development of more efficient manufacturing methods is of great interest. Sheet forming of thermoset prepreg, also known as hot drape forming, has been a promising manufacturing method for decades. An automatic tape layer (ATL) can be used to perform the lay-up in an efficient way. The flatly stacked unidirectional prepreg forms a sheet to be formed over a given mould. Knowledge about the materials forming behaviour is important to reach the required shape without flaws, such as wrinkles. An experimental approach is developed to investigate the intra- (within the layer) and interply deformation. The intraply deformation properties are registered by the use of a bias-extension test and a digital image correlation (DIC) equipment. To measure the interlaminar (between the layers) friction in the prepreg/prepreg interface a specialized rig is designed and built. The two tested materials are Cycom® HTA/977-2 from Cytec and HexPly® T700/M21 from Hexel, which are examples of the second and third generation of carbon fibre/epoxy prepreg. Where M21 includes craze stoppers in form of thermoplastic particles, the 977-2 has the same function but in melted stage. These particles seem to influence both the intraply deformation modes and increase the level of friction between layers. The results from the bias-extension test was compared with the theory of pin-jointed net (PJN) and it was found that M21 behaves accordingly. The measured rotation for 977-2 is less than the theoretical, this due to slippage. The rate of deformation seems to have an influence not only on the load level, but also in the mode of deformation. Both for the interlaminar and intraply deformation the resistance to motion were much larger for M21 than 977-2. / KEKS (kostnadseffektiva kompositer)

Mortality due to cancer is a global health issue that can be improved through further development of diagnostic and prognostic tools. Recent advancements in technologies aiding cancer research have made significant strides, however a demand for a non-invasive clinically relevant point-of-care tools exists. To accomplish this feat, the desired instrument needs to be low-cost, easy-to-operate, efficient, and have rapid processing and analysis. Microfluidic platforms in cancer research have proven to be advantageous due to its operation at the microscale, which has low costs, favorable physics, high precision, short experimentation time, and requires minimal reagent and sample sizes. Label-free technologies rely on cell biophysical characteristics to identify, evaluate, and study biological samples. Biomechanical probing of cells through deformability assays provides a label-free method of identifying cell health and monitoring response to physical and chemical stimuli. Bioimpedance analysis is an alternative versatile label-free method of evaluating cell characteristics by measuring cell response to electrical signals. Microfluidic technologies can facilitate biomechanical and bioelectrical analysis through deformability assays and impedance spectroscopy. This dissertation demonstrates scientific contributions towards single-cell analysis and liquid biopsy devices focusing on cancer research. First, cell deformability assays were improved through the introduction of multi-constriction channels, which revealed that cells have a non-linear response to deformation. Combining impedance analysis with microfluidic deformability assays provided a large dataset of mechano-electrical information, which improved cell characterization and greatly decreased post-processing times. Next, two unique biosensors demonstrated improved throughput while maintaining sensitivity of single-cell analysis assays through parallelization and incorporating machine learning for data processing. Liquid biopsies involve studying cancer cells in patient vascular systems, called circulating tumor cells (CTCs), through blood samples. CTC tests reveal valuable information on patient prognosis, diagnosis and can aide therapy selection in a minimally invasive manner. This body of work presents two liquid biopsy devices that enrich murine and human blood samples and isolate CTCs to ease detection and analysis. Additionally, a microfluidic CTC detection biosensor is introduced to reliably count and identify cancer cells in murine blood, where an extremely low-cost version of the assay is also validated. Thus, the assays presented in this dissertation show promise of microfluidic technologies towards point-of-care systems for cancer research. / Doctor of Philosophy / Cancer is the second leading cause of death worldwide with approximately 2 million new cases each year in the just United States. Significant research development for diagnostic and prognostic tools have been conducted, however they can be expensive, invasive, time-consuming, unreliable, and not always easily accessible. Thus, a tool that is cheap, minimally invasive, easy-to-use, and robust needs to be developed to combat these issues. Typical cancer studies have primarily focused on biological and biochemical methods for evaluation; however, researchers have begun to leverage small-scale biosensors that utilize biophysical attributes. Recent studies have proven that these lab-on-a-chip technologies can produce meaningful results by exploiting these biophysical characteristics. Microfluidics is a science that consists of sub-millimeter sized channels which show a great deal of promise as they require minimal materials and can quickly and efficiently analyze biological samples. Label-free methods of studying cells rely on their physical properties, such as size, deformability, density, and electrical properties. These biophysical characteristics can be easily obtained at the single-cell level through microfluidic-based assays. Measuring and monitoring these attributes can provide valuable information to help understand cancer cell response to stimuli such as chemotherapeutic drugs or other therapies. A liquid biopsy is a non-invasive method of evaluating cancer patients by studying circulating tumor cells (CTCs) that exist in their blood. This dissertation reports a wide range of label-free microfluidic assays that evaluate and study biological samples at the single-cell level and for liquid biopsies. These assays consist of microfluidic channels with sensors that can rapidly obtain biophysical characteristics and process blood samples for liquid biopsy applications. Uniquely modifying microfluidic channel geometries and sensor configurations improved upon previously developed single-cell and CTC-based tools. The resulting devices were low in cost, easy-to-use, efficient, and reliable methods that alleviates current issues in cancer research while showing clinical utility.

Human red blood cells (RBCs) must undergo severe deformation to pass through narrow capillaries and submicronic splenic slits for several hundred thousand times in their normal lifespan. Studies of RBC biomechanics have been mainly focused on cell deformability measured from a single application of stress using classical biomechanical techniques, such as optical tweezers and micropipette aspiration. Mechanical fatigue effect on RBCs under cyclic loadings of stress that contributes to the membrane failure in blood circulation is not fully understood. This research developed a new experimental method for mechanical fatigue testing of RBCs using amplitude-modulated electro-deformation technique. Biomechanical parameters of individually tracked RBCs show strong correlations with the number of the loading cycles. Effects of loading configurations on the cellular fatigue behavior of RBCs is further studied. The results uniquely establish the important role of mechanical fatigue in influencing physical properties of biological cells. They further provide insights into the accumulated membrane damage during blood circulation, paving the way for further investigations of the eventual failure of RBCs in various hemolytic pathologies. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2019. / FAU Electronic Theses and Dissertations Collection

No description available.

Submitted by Dilene Paulo (dilene.fatima@ufcg.edu.br) on 2018-03-20T14:02:41Z No. of bitstreams: 1 THAYS NOGUUEIRA RODRIGUES - DISSERTAÇÃO PPGECA 2017.pdf: 3647526 bytes, checksum: 1eb7aeb580495b958b5f2e74b27bcff1 (MD5) / Made available in DSpace on 2018-03-20T14:02:41Z (GMT). No. of bitstreams: 1 THAYS NOGUUEIRA RODRIGUES - DISSERTAÇÃO PPGECA 2017.pdf: 3647526 bytes, checksum: 1eb7aeb580495b958b5f2e74b27bcff1 (MD5) / CNPq / O ensaio California Bearing Ratio (CBR) “in situ” determina a capacidade de suporte das camadas dos pavimentos, apresenta resultados mais representativos do que os obtidos em laboratório por serem as amostras ensaiadas em condições reais de umidade e confinamento. Entretanto o ensaio envolve equipamentos pesados que dificultam a locomoção e instalação, tornando-o oneroso. O Light Weight Deflectometer (LWD) é um ensaio não destrutivo realizado “in situ” que fornece o módulo de deformabilidade dinâmico do solo. A sua utilização na avaliação de camadas de pavimentos tem sido impulsionada devido à simplicidade de execução e portabilidade do equipamento. Portanto, este trabalho objetiva comparar os resultados de índice de CBR e módulo de deformabilidade, ambos obtidos in situ, por meio de análise de regressão, com o intuito de avaliar a utilização de um equipamento simplificado e de baixo custo de realização de ensaio na determinação da capacidade estrutural das camadas de subleitos. A fase experimental desta pesquisa consistiu inicialmente na escolha de ruas não pavimentadas que estivessem distribuídas na cidade de Campina Grande, em seguida foram realizados “in situ” os ensaios de LWD, CBR, peso específico aparente e coleta de amostras para a realização em laboratório dos ensaios de caracterização, compactação e CBR. Posteriormente as análises de regressão foram realizas a fim de obter uma Equação que correlacionasse o valor do módulo de deformabilidade com o valor do índice de CBR “in situ”. De modo geral, a pesquisa mostrou que há uma tendência de comportamento semelhante entre os parâmetros de deformabilidade e capacidade de suporte obtido a partir dos LWD e CBR “in situ”, e uma correlação pôde ser estabelecida para que se pudesse prever o valor da capacidade de suporte de camadas do subleito “in situ” a partir da realização do ensaio LWD de forma confiável, facilitando assim a obtenção deste parâmetro geotécnico a partir de um ensaio de fácil execução, mais rápido e menos dispendioso. / The CBR "in situ" test determinates the bearing capacity of the pavement layers and it’s performed on the field, which results that are more representative than those obtained in the laboratory because the samples are tested under real conditions of moisture and containment. However, this assay involves heavy equipments which make the process is harder in terms of locomotion and installation and consequently making him more expensive. The development of new methodologies of pavement sizing (empirical-mechanistic models) makes it necessary to evaluate the characteristics of the materials that constitute the pavement, from an investigation that can predict the behavior of these materials whereas the tension-deformation stage, caused by the passage of vehicles. The Light Weight Deflectometer (LWD) it’s a non destructive test conducted “in situ” that provides the dynamic soil deformability modulus. The use of this module in the assessment of pavement layers has been stimulated due to the simplicity of the execution and the portability of the equipment. Therefore, this work aims to compare the index results of CBR and deformability module, both obtained “in situ”, through regression analysis, in order to rate the use of a cheaper and simplified equipment to perform a test in the determination of the structural capacity of the subgrade layers. The experimental stage of this research is based on: the choice of the unpaved streets along the city of Campina Grande; the perform “in situ” of the LWD test, CBR “in situ” and the Apparent specific mass “in situ”; sample collections; were carried out in situ. Description of soils in laboratory and analysis of correlations. Altogether, the research shows that there is a trend of similar behavior between parameters of deformability and support capacity obtained from LWD and CBR “in situ”, respectively, and a correlation could be established so that we can predict the value of the layers support capacity of subgrade “in situ” from the performance of the LWD assay in a reliable way, thus facilitating the achievement of this geotechnical parameter from an easy-to-execute, faster and less expensive test.

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第22473号 / 工博第4734号 / 新制||工||1739(附属図書館) / 京都大学大学院工学研究科合成・生物化学専攻 / (主査)教授 梅田 眞郷, 教授 森 泰生, 教授 秋吉 一成 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM

This paper presents results of an experimental investigation to study the structural performance and deformability of a concrete bridge deck reinforced with corrosion resistant reinforcing (CRR) bars, i.e., bars that exhibit improved corrosion resistance when embedded in concrete as compared to traditional black steel. Flexural tests of one-way slabs were conducted to simulate negative transverse flexure over a bridge girder as assumed in the commonly employed strip design method. The bar types studied were Grade 60 (uncoated), epoxy-coated reinforcing (ECR, Grade 60), Enduramet 32 stainless steel, 2304 stainless steel, MMFX2, and glass fiber reinforced polymer (GFRP). The experimental program was designed to evaluate how a one-to-one replacement of the Grade 60 with CRR, a reduction of concrete top clear cover, and a reduction in bar quantities in the bridge deck top mat influences flexural performance at service and ultimate limit states. Moment-curvature predictions from the computer-based sectional analysis program Response 2000 were consistent with the tested results, demonstrating its viability for use with high strength and non-metallic bar without a defined yield plateau.    Deformability of the concrete slab-strip specimens was defined with ultimate-to-service level ratios of midspan deflection and curvature. The MMFX2 and Enduramet 32 one-to-one replacement specimens had deformability consistent with the Grade 60 controls, demonstrating that bridge deck slabs employing high strength reinforcement without a defined yield plateau can still provide sufficient ductility at an ultimate limit state. A reduction in bar quantity and cover provided acceptable levels of ductility for the 2304 specimens and MMFX2 reinforced slabs. / Master of Science

Cancer is a major health issue that has been associated with over 80 million deaths worldwide in the last decade. Recently, significant improvements have been made in terms of treatment and diagnosis. However, despite these advancements there is still a demand for low-cost, high-accuracy, and easy-to-use technologies capable of classifying cells. Analysis of cell behavior in microfluidic deformability assays provides a label-free method of observing cell response to physical and chemical stimuli. This body of work shows advancements made toward reaching our goal of a robust and cost-effective biosensing device that allows for the identification of normal and cancer cells. These devices can also monitor cell responses to physical and chemical stimuli in the form of mechanical deformation and chemotherapeutic drugs, respectively. Our initial design was a microfluidic device that consisted of three channels with varying deformation and relaxation regions. Cell velocities from the deformations regions allowed us to distinguish between normal and cancer cells at the single-cell level. The next design used a singular deformation channel that was embedded with an array of electrodes in order to measure entry time, transit time and velocities as a single cell passes through the channel. These factors were found to reveal information about the biomechanical properties of single cells. Embedded electrodes were implemented in order to reduce post processing times of the data analysis and provide more insight into the bioelectrical information of cells. Finally, we report a microfluidic device with parallel deformation channels and a single electrode pair to improve throughput and automate data collection of deformability assays. This thesis demonstrates how microfluidic deformability assays, with and without embedded electrodes, show promising capabilities to classify different cells based on their biophysical traits which can be utilized as a valuable tool for testing responses to physical and chemical stimuli. / MS

The dissertation details work aimed toward the development and implementation of a 3-D impact fragmentation module to perform rock fall analysis by taking into account impact fragmentation. This fragmentation module is based on a database of a large set of impact simulations using a fully calibrated discrete element model (DEM), and is employed to predict impact fragmentation processes in rockfall analysis by either training a neural network model or linearly interpolating the database. A DEM was employed to model impact fragmentation in the study. A DEM code was developed from scratch. The model was first calibrated and verified with experimental results to demonstrate the capability of modeling both quasi-static and dynamic material behavior. Algorithms to calibrate the model’s micro-parameters against triaxial tests on rocks were presented. Sensitivity analyses were used to identify the deformability micro-parameters by obtaining relationships between microscopic and macroscopic deformability properties. The strength model parameters were identified by a global optimization process aimed at minimizing the difference between computed and experimental failure envelopes. When applied to the experimental results of tested granite, this calibration process produced a good agreement between simulated and experimental results for both deformability and strength properties. Dynamic compression and SHPB tests were performed to verify the dynamic model. A strain-rate-dependent dynamic strength was observed in the experimental results. This strain-rate-dependent dynamic strength was also confirmed by the numerical results. No rate-dependent constitutive model was used in the DEM to simulate dynamic behavior. This simulated rate-dependent dynamic strength can be attributed to material inertia because the inertia inhibits crack growth. Some fundamental mechanisms of impact fragmentation associated with rockfalls were then numerically investigated. The developed DEM code was coupled with a simplified impact model inspired by the theory of dynamic foundations. It has been shown that the magnitude of impact velocity, the angle of the incidence, the ground condition all play very important roles in impact fragmentation. Several case studies were performed to validate the developed impact fragmentation module in rock fall analysis. It has been demonstrated that the developed fragmentation module can reasonably predict impact fragmentation and perform some risk analysis in rock fall analysis. / text