Дисертації з теми "Damage Diagnosi"
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1
CIVERA, MARCO. "Vibration-based Assessment of Structural Changes in the Linear and Nonlinear Response of Mechanical Structures for Aerospace Applications." Doctoral thesis, Politecnico di Torino, 2021. http://hdl.handle.net/11583/2932751.
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2
Stubbs, Peter John. "Cardiac Troponin T and myocardial damage." Thesis, University College London (University of London), 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.309504.
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3
Ahmed, Usman. "Protein damage markers in diagnosis, progression and treatment of arthritis." Thesis, University of Warwick, 2013. http://wrap.warwick.ac.uk/58716/.
Повний текст джерелаАнотація:
Osteoarthritis (OA) and rheumatoid arthritis (RA) are joint diseases associated with damage and proteolytic loss of protein from affected joints. The types and amounts of protein damage and related proteolytic debris in synovial fluid and released into the circulation has not been studied comprehensively. The aim of this study is to quantify levels of protein damage in a cross-sectional pilot study of synovial fluid and plasma of patients with early-stage OA (eOA) and RA (eRA), and self-resolving arthritis (non-RA), and compare these with patients with advanced stage OA (aOA) and RA (aRA), and with plasma of healthy subjects. Patients with eOA, aOA, eRA and non-RA were recruited by collaborating clinicians from rheumatology and orthopaedic clinics in hospitals in Coventry, Birmingham, Ipswich and Exeter and synovial fluid and plasma samples collected from patients with consent. Major chemically-defined markers of protein damage by glycation, oxidation, nitration and citrullination were quantified in sample protein and in ultrafiltrate (glycated, oxidized and nitrated amino acids) by stable isotopic dilution analysis liquid chromatography-tandem mass spectrometry. Hydroxyproline was also determined. Our results demonstrated varying degrees of changes within protein damage marker concentrations across all subject groups, however there were many significant changes. Protein oxidation and advanced glycation endproducts were noted to be elevated both synovial fluid and plasma of patients with aRA and aOA with elevated levels also noted in eRA and eOA synovial fluid. Citrullinated proteins were noted to be markedly increased in plasma protein in both eOA and eRA. Markers of nitration were also elevated in non-RA plasma there was a decrease in nitration despite increases in glycation and oxidation. Changes in damaged amino acids in synovial fluid and plasma were similar across all patients. In aRA and aOA there was increased amino acid oxidation and advanced glycation and decreased amino acid nitration. There was also increased hydroxyproline in plasma. In eRA and eOA there was increased amino acid oxidation and increased advanced glycation in eRA (Nω-carboxymethylarginine). Changes in amino acid oxidation and advanced glycation were restricted to plasma in non-RA. The changes in protein damage and citrullination were characteristic “signatures” that allowed production of data trained algorithms with over ≥ 97% specificity and sensitivity for diagnosis and discrimination of eOA, eRA and non-RA. This study provides the first comprehensive attempt at quantification of protein damage markers in joint disease using LC-MS/MS techniques – a gold standard. The improved characterisation of protein damage and related metabolites will likely advance understanding of early-stage processes in joint degeneration which is still poorly understood and may provide novel plasma biomarkers for diagnosis and risk of disease progression.
4
Peetathawatchai, Chatmongkol. "The applicability of neural network systems for the structural damage diagnosis." Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/40591.
Повний текст джерелаАнотація:
Thesis (Sc. D.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 1996.Includes bibliographical references (leaves 252-266).
by Chatmongkol Peetathawatchai.
Sc.D.
5
Wang, Kaihong. "Vibration Analysis of Cracked Composite Bending-torsion Beams for Damage Diagnosis." Diss., Virginia Tech, 2004. http://hdl.handle.net/10919/29891.
Повний текст джерелаАнотація:
An analytical model of cracked composite beams vibrating in coupled bending-torsion is developed. The beam is made of fiber-reinforced composite with fiber angles in each ply aligned in the same direction. The crack is assumed open. The local flexibility concept is implemented to model the open crack and the associated compliance matrix is derived. The crack introduces additional boundary conditions at the crack location and these effects in conjunction with those of material properties are investigated. Free vibration analysis of the cracked composite beam is presented. The results indicate that variation of natural frequencies in the presence of a crack is affected by the crack ratio and location, as well as the fiber orientation. In particular, the variation pattern is different as the magnitude of bending-torsion coupling changes due to different fiber angles. When bending and torsional modes are essentially decoupled at a certain fiber angle if there is no crack, the crack introduces coupling to the initially uncoupled bending and torsion.
Based on the crack model, aeroelastic characteristics of an unswept composite wing with an edge crack are investigated. The cracked composite wing is modeled by a cracked composite cantilever and the inertia coupling terms are included in the model. An approximate solution on critical flutter and divergence speeds is obtained by Galerkin's method in which the fundamental mode shapes of the cracked wing model in free vibration are used. It is shown that the critical divergence/flutter speed is affected by the elastic axis location, the inertia axis location, fiber angles, and the crack ratio and location. Moreover, model-based crack detection (size and location) by changes in natural frequencies is addressed. The Cawley-Adams criterion is implemented and a new strategy in grouping frequencies is proposed to reduce the probability of measurement errors. Finally, sensitivity of natural frequencies to model parameter uncertainties is investigated. Uncertainties are modeled by information-gap theory and represented with a collection of nested sets. Five model parameters that may have larger uncertainties are selected in the analysis, and the frequency sensitivities to uncertainties in the five model parameters are compared in terms of two immunity functions.Ph. D.
6
Gregory, Erin Kathleen Taylor. "Cognitive and Perceptual-Motor Indicators of Lateralized vs. Diffuse Brain Damage in Adults." Thesis, University of North Texas, 2002. https://digital.library.unt.edu/ark:/67531/metadc3287/.
Повний текст джерелаАнотація:
Among the goals of the neuropsychological assessment are to detect the presence of brain damage, localize which areas of the brain may be dysfunctional and describe subsequent functional impairments. The sensitivity of neuropsychological instruments in carrying out these functions is a question of some debate. The purpose of this study is to determine the utility of lateralizing indicators from the WAIS-III, McCarron Assessment of Neuromuscular Development (MAND) and Haptic Visual Discrimination Test (HVDT), from the McCarron-Dial System Neuropsychological Assessment Battery (MDS), in ascertaining the presence or absence of brain damage as well as location of lesion. The classification accuracies of using performance level indicators from these tests and lateralizing indicators, alone and together, were compared.
7
Layton, Donald Charles. "The relationship between Glasgow Coma Scale ratings and the neuropsychological functioning in acutely head injured thirteen through twenty-six year olds." Virtual Press, 1985. http://liblink.bsu.edu/uhtbin/catkey/442601.
Повний текст джерелаАнотація:
The purpose of this study was to determine if the Glasgow Coma Scale (GCS) provides a valid indication of severity after closed head injury. A second purpose was to determine the nature of the deficits seen with head injured persons shortly after injury.The subjects were 69 patients ages 13 through 26 selected from consecutive closed head injury admissions to a large acute care hospital. The subjects received comprehensive neuropsychological testing after having passed the Galveston Orientation and Amnesia Test.Two a priori hypotheses were specified for each of eight neuropsychological test groupings (i.e., motor, memory, visuographic, achievement, abstraction and concept formation, language, problem solving, and psychometric intelligence). For each of the eight test groupings two, one-way multivariate analyses of covariance (MANCOVA) were used to determine statistical significance. Premorbid IQ was used as a covariate in all of the analyses. Specifically, these a priori contrasts were GCS group (8 compared with GCS group 9-15 and GCS group 9-12 compared with GCS group 13-15. Each of the significant MANCOVA tests was followed with discriminant analysis.The results revealed that 15 out of the 16 null hypotheses were rejected (p<.05 or less) thus providing clear evidence for the usefulness of the GCS as an indicator of the severity of injury. Most notable of the results is that the GCS group comparison of 9-12 and 13-15 reached significance in seven of the eight comparisons. Given this finding, there seems justification for the GCS division of 9-12 denoting a moderately injured group and 13-15 denoting a mildly injured group as was proposed in previous research. Redundancy indexes of 6% to 25% were obtained which indicated small to relatively large effect sizes for the various criterion variates.With discriminant analysis it was determined that accurate classification into GCS groups could be achieved in 64% to 94% of the cases based upon a combination of premorbid IQ and the criterion variates. This represented an increase in classification accuracy of from 13% to 51%to be over what could be accomplished with knowledge of the premorbid IQ alone. The motor test composite, problem solving test composite and abstraction and concept formation composite revealed the highest rates of reclassification.
8
Scholtz, Brendon P. "Effects of Cautioning and Education in the Detection of Malingered Mild Traumatic Brain Injury." Thesis, University of North Texas, 2006. https://digital.library.unt.edu/ark:/67531/metadc5247/.
Повний текст джерелаАнотація:
This study examined the effectiveness of cautioning and education on simulating a mild traumatic brain injury on several neuropsychological measures. The measures used included the Word Memory Test (WMT), Wechsler Adult Intelligence Scales® - Third Edition (WAIS®-III), Wechsler Memory Scales®-3rd Edition instrument (WMS®-III), 16-item version of the Rey Memory Test, and a self-report symptom checklist. Five experimental groups were used including clinical and non-clinical controls, as well as three simulation groups. The design and implementation of this study also attempted to correct several methodological short comings of prior research by increasing the incentives for participants, expanding the generalizability of findings and examining research compliance and participant self-perception through debriefing. Discriminant analysis was utilized to determine if specific functions existed that would correctly classify and distinguish each experimental group. Several discriminant functions had at least moderate canonical correlations and good classification accuracy. Results also include utility estimates given projected varying base rates of malingering.
9
Grimshaw, P. N. "Quantitative assessment of knee instability." Thesis, University of Salford, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.234593.
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10
Taylor, Erin Kathleen. "The utility of the McCarron-Dial System in determining location of brain lesion." Thesis, University of North Texas, 2004. https://digital.library.unt.edu/ark:/67531/metadc4570/.
Повний текст джерелаАнотація:
Among the goals of neuropsychological assessment are to detect the presence of brain damage, localize which areas of the brain may be dysfunctional, and describe subsequent functional impairments. The sensitivity of neuropsychological instruments in carrying out these functions has long been a question of debate. The purpose of the present study was to determine the utility of various performance level indictors and lateralizing indicators from the McCarron-Dial System Neuropsychological Assessment Battery (MDS) in ascertaining the presence or absence of brain damage as well as location of lesion. Models used in the present study appear to provide increased classification accuracy compared to other studies utilizing the MDS. The MDS was also shown to be comparable to other well-known neuropsychological batteries, including the Halstead-Reitan Neuropsychological Test Battery (HRB) and the Luria-Nebraska Neuropsychological Battery (LNNB) with regard to distinguishing between those with brain damage and normal controls, and also localizing brain lesion. The results of this study offer clinicians parsimonious models to evaluate for presence of lesion and its location so this information may be used to make accurate, thorough diagnoses and appropriate treatment and rehabilitation recommendations.
11
Liu, Chang. "Singular Value Decomposition Applied to Damage Diagnosis for Ultrasonic Guided Wave Structural Health Monitoring." Research Showcase @ CMU, 2014. http://repository.cmu.edu/dissertations/402.
Повний текст джерелаАнотація:
A structural health monitoring (SHM) system takes frequent monitoring records from permanently installed transducers on structures, and uses the information to identify potential structural degradation and to proactively maintain the structures. Guided wave testing is an attractive technique for structural health monitoring of large structures, because guided waves can propagate long distance and are sensitive to subtle and hidden damage. In guided wave SHM systems, ultrasonic records are often affected by environmental and operational variations, which produce undesired changes and cause false results. Moreover, although continuous monitoring produces sufficient information regarding structural integrity, we lack a data processing tool to extract, store, and utilize the damage-sensitive information to leverage the accuracy and robustness of damage detection and localization. In this dissertation, we develop a data-driven framework based on singular value decomposition that processes guided wave monitoring records to separate damage-related information from effects of environmental and operational variations. The method decomposes sequential monitoring records to reveal trends of different variations, and identifies the singular vector associated with damage development. Combined with delay-and-sum localization method, we can robustly localize the damage using the right singular vectors, which resemble the scatter signal and are robust to environmental and operational variations. The SVD framework is then refined, by adaptively updating the singular vectors with each arriving ultrasonic record , to achieve online damage detection and localization. The SVD damage diagnosis methodology is applied experimentally to detect and localize damage in plate and pipe structures, both in laboratory tests and in field tests.
12
Xiao, Wenchang. "Structural Health Monitoring and Fault Diagnosis based on Artificial Immune System." Digital WPI, 2012. https://digitalcommons.wpi.edu/etd-theses/169.
Повний текст джерелаАнотація:
This thesis presents a development of Structural Health Monitoring (SHM) and Fault Diagnosis based on Artificial Immune System (AIS), a biology-inspired method motivated from the Biological Immune System (BIS). Using the antigen to model structural health or damage condition of specific characteristics and the antibody to represent an information system or a database that can identify the specific damage pattern, the AIS can detect structural damage and then take action to ensure the structural integrity. In this study the antibodies for SHM were first trained and then tested. The feature space in training includes the natural frequencies and the modal shapes extracted from the simulated structural response data including both free-vibration and seismic response data. The concepts were illustrated for a 2-DOF linear mass-spring-damper system and promising results were obtained. It has shown that the methodology can be effectively used to detect, locate, and assess damage if it occurred. Consistently good results were obtained for both feature spaces of the natural frequencies and the modal shapes extracted from both response data sets. As the only exception, some significant errors were observed in the result for the seismic response data when the second modal shape was used as the feature space. The study has shown great promises of the methodology for structural health monitoring, especially in the case when the measurement data are not sufficient. The work lays a solid foundation for future investigations on the AIS application for large-scale complex structures.
13
Carneiro, Sergio H. S. "Model-Based Vibration Diagnostic of Cracked Beams in the Time Domain." Diss., Virginia Tech, 2000. http://hdl.handle.net/10919/28717.
Повний текст джерелаАнотація:
A time-domain model-based crack diagnostic methodology using vibration data is presented. Most of the damage detection methods proposed to date are based on modal parameters and are limited by the loss of information caused by data reduction and by the implicit assumption of linearity. The use of time domain information permits the direct inclusion of the nonlinear behavior due to crack opening-closure cycles. In addition, very little information is lost, since no signal processing or parameter identification steps are involved. The proposed method is based on a continuous model for the transverse vibrations of beams consisting of partial differential equations of motion with varying coefficients to account for the presence of damage.
In order to provide accurate representation of the structure's behavior over a broader frequency range, a new continuous cracked beam model including shear effects and rotatory inertia is developed using the Hu-Washizu-Barr variational method.
The resulting equations of motion are discretized by a Galerkin method using local B-splines as test functions. The crack is assumed to be either fully open or fully closed, resulting in a bilinear system. The simultaneous identification of crack location and depth is performed by minimizing the norm of the differences between the numerical and experimental time responses to multiple excitations. Impact, low frequency sinusoidal and Schroeder--phased multisine inputs are investigated as potential excitation methods. The cost function to be minimized presents several local minima that are shown to be related to the length of the response records. A genetic algorithm is used to overcome the multimodal nature of the objective function. The methodology is validated through simulated identifications of several damage scenarios. The importance of the inclusion of the nonlinear behavior is addressed, and the effects of model uncertainties and measurement noise are quantified in terms of minimum identifiable crack size.Ph. D.
14
Wang, Wei Ji. "Gearbox condition monitoring and early damage diagnosis by two and three dimensional vibration signal analysis." Thesis, University of Oxford, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.334237.
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15
Herrera, Liana J. Marmol. "Artificial intelligence methods for the diagnosis of myocardial damage in Chagas' disease using electrocardiographic signals." Thesis, University of Reading, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.314320.
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16
Bass, Catherine. "Performance of Children With and Without Traumatic Brain Injury on the Process Scoring System for the Intermediate Category Test." Thesis, University of North Texas, 1997. https://digital.library.unt.edu/ark:/67531/metadc278018/.
Повний текст джерелаАнотація:
The clinical utility of the Intermediate Category Test, a measure of executive functioning in children 9 to 14 years of age, is currently limited by the availability of only a Total Error score for normative interpretation. The Process Scoring System (PSS) was developed to provide a standardized method of assessing specific processing patterns and problem-solving errors. The purpose of this study was to determine the ability of the PSS scores to discriminate between children with and without suspected executive deficits, thereby providing evidence of criterion-related validity.
17
Norton, Carole Lynn. "Assessment of Brain Damage: Discriminant Validity of a Neuropsychological Key Approach with the McCarron-Dial System." Thesis, North Texas State University, 1985. https://digital.library.unt.edu/ark:/67531/metadc330881/.
Повний текст джерелаАнотація:
The present study investigates the predictive accuracy of a key approach to interpretation of the verbal-spatialcognitive (VSC) and sensorimotor (SM) factors of the McCarron-Dial System (MDS). The subjects include 99 brain damaged and 30 normal adults. The following research questions are addressed: (a) Does the neuropsychological key classify brain damaged and non-brain damaged subjects at a level significantly above chance? (b) Among the brain damaged subjects, does the neuropsychological key identify right brain damage, left brain damage and diffuse brain damage at an accuracy level significantly above chance? (c) Is the neuropsychological key approach superior to the empirical model derived from discriminant function analysis in predictive accuracy? The neuropsychological key correctly classifies 90% of the cases as brain damaged and 90% of the cases as non-brain damaged, for a total of 89.9% predictive accuracy. The obtained Kappa coefficient of .74 is statistically significant. The key accurately classifies 71.4% of the brain damaged group as right damage, 70% as left damage, and 93.8% as diffuse damage, for a total predictive accuracy of 7 9.5%. The Kappa coefficient of .68 is statistically significant. Chi square analysis of the difference between the key approach and multiple discriminant function analysis reveals that no significant difference is present between the accuracy of the two approaches in differentiating between brain damaged and non-brain damaged, or in differentiating among left, right and diffuse brain damage. The results support the validity of a neuropsychological key approach to interpretation of the McCarron-Dial System, although cross-validation is indicated to confirm the stability of these results. Differences in sex, educational level and racial composition of the comparison groups may have affected the results obtained. Refinement of the key in future research and the addition of test instruments assessing memory, auditory processing, attention and emotional/behavioral variables are recommended.
18
Collingwood, Lisa M. (Lisa Marie). "Performance of Psychiatric and Head Injury Patients on the General Neuropsychological Deficit Scales." Thesis, University of North Texas, 1997. https://digital.library.unt.edu/ark:/67531/metadc278771/.
Повний текст джерелаАнотація:
Reitan and Wolfson's General Neuropsychological Deficit Scale and Left and Right Neuropsychological Deficit Scales were applied to Halstead-Reitan test data of individuals with psychotic or substance abuse disorders with and without a head injury.
19
Winfield, Kaye R. "Extraction of desmosines from urine : an indicator for inflammatory lung damage." University of Western Australia. School of Paediatrics and Child Health, 2007. http://theses.library.uwa.edu.au/adt-WU2007.0059.
Повний текст джерелаАнотація:
[Truncated abstract] Urinary desmosines have been proposed as a biomarker for inflammatory lung damage. Desmosine, a breakdown product of elastin, is an effective marker of the degradation of elastin and has been studied in many disease scenarios where there is acute and chronic lung inflammation. Lung matrix degradation has been proven in vitro and in vivo with many experiments showing that the excess proteases degrades lung matrix. The secretion of proteases by neutrophils is an innate response of the body to the invasion by micro organisms and when secreted in excess, the protective anti-protease mechanism is swamped. Chronic inflammation and persistent infection eventually leads to bronchiectasis and respiratory failure. Urinary desmosine has been shown to be elevated in respiratory conditions with acute and chronic inflammation . . . Urinary desmosine levels in a large cohort of healthy children have been established using this method and predictive Z-score formulae have been developed to use in children with lung disease. Exploration of these scores in children with CF have shown that the levels of urinary desmosine appear to be sensitive to the clinical setting, where high urinary desmosine levels were present during exacerbation and significantly reduced when treated for infection with antibiotic therapy and physiotherapy. The study of young children under the age of seven was undertaken to determine if the urinary desmosine levels could indicate when lung damage was occurring and to determine what mechanisms might be involved. Since there appeared to be no apparent relationship between elevated desmosines and proteases in the lung in young children with CF, further studies are required to define the mechanisms behind increased elastin metabolism in those children.
20
Grub, Anna. "Schadenersatzansprüche bei Geburt eines behinderten Kindes nach fehlerhafter Pränataldiagnostik in der Spätschwangerschaft /." [S.l. : s.n.], 2006. http://www.gbv.de/dms/ilmenau/toc/512374953.PDF.
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21
Colaluca, Beth. "Validation of the Expanded McCarron-Dial System for Diagnosis of Neuropsychological Dysfunction in Adults." Thesis, University of North Texas, 1998. https://digital.library.unt.edu/ark:/67531/metadc279403/.
Повний текст джерелаАнотація:
The McCarron-Dial System (MDS) has successfully predicted vocational and independent living outcomes with neuropsychologically disabled individuals receiving rehabilitation services. In addition, preliminary validation studies suggest that the abbreviated MDS is useful for clinical neuropsychological diagnosis. The present study represents part of an ongoing research project aimed at validating the expanded version of the MDS for diagnosis of neuropsychological dysfunction. Specifically, it was hypothesized that the expanded MDS would be able to accurately discriminate between brain-damaged and non-brain-damaged individuals. Accurate diagnosis facilitates rehabilitation efforts for individuals with neuropsychological disabilities and the data profile provided by the expanded version of the MDS can consequently form the basis from which more complete individual treatment and rehabilitation plans can be conceptualized.
22
Puelz, Michael. "A program to generate and validate new test versions of a neuropsychological planning test." Virtual Press, 1991. http://liblink.bsu.edu/uhtbin/catkey/834522.
Повний текст джерелаАнотація:
Computers are used for diagnostic and training in the neuropsychological rehabilitation. PLANTEST is a program for the IBM-PC that was developed for diagnostic support. It implements a test that gives information about the reduced ability of brain-injured patients to make plans regarding a certain task.The presented thesis describes a knowledge-based system that can be used to develop new test versions for PLANTEST. The program is called SolvePT and it can prove the solubility of test material used in PLANTEST. It can also automatically generate new test material. The program uses an exhaustive forward-chaining, depth-first search and is implemented in Prolog. The datastructures and algorithm of the program as well as space and time requirements are discussed.Department of Computer Science
23
Beck, Kelley D. Franks Susan F. "Personality and the prediction of outcome following rehabilitation in persons with acquired brain injuries the Millon Behavioral Medicine Diagnostic (MBMD) /." [Denton, Tex.] : University of North Texas, 2008. http://digital.library.unt.edu/permalink/meta-dc-9121.
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Віхрова, Ірина Олександрівна, Ирина Александровна Вихрова, Iryna Oleksandrivna Vikhrova, Андрій Миколайович Лобода, Андрей Николаевич Лобода, and Andrii Mykolaiovych Loboda. "Significance of urinary Aminopeptidase N in early diagnosis of kidney damage in children with type 1 diabetes mellitus." Thesis, Lithuanian University of Health Sciences, 2021. https://essuir.sumdu.edu.ua/handle/123456789/83663.
Повний текст джерелаАнотація:
Мета. Метою цього дослідження було вивчити особливості рівнів амінопептидази N (ANPEP) в сечі у дітей залежно від тривалості діабету.
Методи. Ми проаналізували 3 групи дітей з цукровим діабетом 1 типу та групу порівняння дітей без діабету з Обласної дитячої клінічної лікарні м Суми. ANPEP вимірювали за допомогою імуноферментного аналізу з використанням набору антитіл до біомаркерів нирок людини (R&D Systems, Міннеаполіс, Міннесота, США). Результати були отримані за допомогою BioRad ChemiDoc Touch. Масиви аналізували напівкількісно з використанням програмного забезпечення BioRad Image Lab.
Результати. У дослідження були включені 47 дітей з діабетом і 8 дітей без діабету. Рівень ANPEP в сечі збільшився в 2,6 рази у дітей з тривалістю діабету менше одного року порівняно з контрольною групою. Рівні ANPEP були підвищені в 3,2 рази у дітей з тривалістю діабету від одного до п'яти років. У дітей з тривалістю діабету понад 5 років маркер збільшився в 2,7 рази.
Висновок. Підвищення рівня ANPEP в сечі спостерігалося в перший рік діабету у дітей. Вимірювання рівня ANPEP в сечі може бути корисним для діагностики діабетичної нефропатії.Цель. Целью настоящего исследования было изучить особенности уровней Аминопептидазы N (ANPEP) в моче у детей в зависимости от продолжительности диабета. Методы. Мы проанализировали 3 группы детей с сахарным диабетом 1 типа и группу сравнения детей без диабета из Областной детской клинической больницы г. Сумы. ANPEP измеряли с помощью иммуноферментного анализа с использованием набора антител к биомаркерам почек человека (R&D Systems, Миннеаполис, Миннесота, США). Результаты были получены с помощью BioRad ChemiDoc Touch. Массивы анализировали полуколичественно с использованием программного обеспечения BioRad Image Lab. Результаты. В исследование были включены 47 детей с диабетом и 8 детей без диабета. Уровень ANPEP в моче увеличился в 2,6 раза у детей с длительностью диабета менее одного года по сравнению с контрольной группой. Уровни ANPEP были повышены в 3,2 раза у детей с длительностью диабета от одного до пяти лет. У детей с длительностью диабета более 5 лет маркер увеличился в 2,7 раза. Заключение. Повышение уровня ANPEP в моче наблюдалось в первый год диабета у детей. Измерение уровня ANPEP в моче может быть полезно для диагностики диабетической нефропатии.
Aim. The aim of the current study was to investigate the features ANPEP levels in urine of children depending on the duration of diabetes. Methods. We analysed 3 groups of children with type 1 diabetes mellitus and comparison group of children without diabetes from Regional Children’s Clinical Hospital in Sumy. ANPEP was measured by ELISA using a Proteome Profiler Human Kidney Biomarker Antibody Array (R&D Systems, Minneapolis, MN, USA). Results were detected with BioRad ChemiDoc Touch. The arrays were analysed semiquantitatively, using BioRad Image Lab Software. Results. The study included 47 children with diabetes and 8 children without diabetes. The level of ANPEP in urine increased 2.6-fold in children with the duration of diabetes below one year compared to the control group. ANPEP levels were elevated 3.2-fold in children with duration of diabetes from one to five years. In children with duration of diabetes duration, the marker increased 2.7 times. Conclusion. Increase urinary ANPEP was observed in the first year of diabetes in children. Measuring the level of ANPEP in urine may be useful for the diagnosis of diabetic nephropathy.
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Mercer, Walt N. (Walt Neilson). "Performance of Brain-Injured versus Non-Brain-Injured Individuals on Three Versions of the Category Test." Thesis, University of North Texas, 1994. https://digital.library.unt.edu/ark:/67531/metadc278878/.
Повний текст джерелаАнотація:
To date, no research exists examining criterion-related validity of alternate, computerized forms of the Category Test. The intent of this study was to address criterion-related validity of three full forms of the Category Test. In that, the goal was to examine equivalency of each version in their ability to differentiate brain-injured from non-brain-injured individuals. Forty-nine (N = 49) healthy adults and 45 (N = 45) brain-injured adults were tested using three versions of the Category Test, the BDI, and the WAIS-R NI. ANOVA indicated no significant differences between versions of the Category Test or an interaction between Category Test version and group membership on the total error score. MANOVA performed between versions of the Category Test and Subtest error scores indicated significant differences between versions on Subtest 3 and Subtest 6. Group membership (brain-injured v. non-brain-injured) produced a significant main effect on all subtests of the Category Test except Subtest 2. Several exploratory analyses were performed examining the relationship between neuropsychological impairment, group membership based on Category Test error scores, and the WAIS-R NI. Clinical applications, such as the use of serial testing to index neurorehabilitation gains, were discussed.
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D'Angelosante, Valentina. "White matter alterations and cognitive assessment in hypertensive patients without damage at conventional neuroimaging." Doctoral thesis, Università degli studi del Molise, 2019. http://hdl.handle.net/11695/86520.
Повний текст джерелаАнотація:
Il progetto di ricerca riportato nella presente tesi riguarda lo studio del danno cognitivo causato dall’ipertensione in relazione al danno della sostanza bianca sottocorticale. Scopo principale del progetto è stato quello di effettuare una valutazione di marcatori precoci di decadimento cognitivo in pazienti con ipertensione arteriosa attraverso tecniche di neuroimaging basate sul tensore di diffusione. Nello specifico, è stato condotto uno studio caso-controllo articolato selezionando pazienti ambulatoriali afferenti al Dipartimento di Angio Cardio Neurologia e Complicanze Neurologiche delle Malattie Internistiche presso I.R.C.C.S. Neuromed, che hanno acconsentito tramite consenso informato, di partecipare al progetto di ricerca. I pazienti ipertesi e il relativo campione di controllo normoteso sono stati sottoposti tutti alla medesima procedura: raccolta anamnesi prossima e remota, acquisizione dati di risonanza magnetica con particolari sequenze di DTI, misurazione pressoria, prelievi ematici, ecocardiogramma, ecocolordoppler TSA e valutazione cognitiva. Il fine è stato quello di individuare il più precocemente possibile segni di danno cerebrale causato da ipertensione non altrimenti individuabile attraverso una canonica RMN encefalica. Ciò è stato possibile tramite l’analisi di trattografia e alla relativa correlazione con i dati ottenuti dalla valutazione cognitiva. Dal punto di vista cerebrale e cognitivo gli ipertesi mostravano una performance significativamente peggiore nel Montreal Cognitive Assessment (MoCA), una batteria di test specificamente disegnata per la valutazione di molteplici funzioni cognitive e validata nelle patologie vascolari, nell’apprendimento e nella velocità di processamento delle informazioni. Mediante imaging cerebrale è stato possibile osservare che, sebbene gli ipertesi non avessero anomalie riscontrabili con metodiche convenzionali, gli indici di trattografia erano significativamente ridotti (FA, MD, RD, AD). In particolare, essi mostravano un’alterazione specifica nelle fibre di proiezione correlate alle funzioni mnemoniche (Anterior Thalamic Radiation), nelle fibre di associazione coinvolte nelle funzioni esecutive (Superior Longitudinal Fasciculus), nelle fibre del sistema callosale coinvolte in compiti di velocità di processamento delle informazioni (Forceps Minor). Correlando questi dati con i dati ottenuti dalle valutazioni cognitive è emerso come le fibre di proiezione e le fibre di associazione correlano con la valutazione della performance cognitiva globale del MoCA e come le fibre callosali correlano con la performance nello Stroop Test. Altresì i punteggi ottenuti nel MoCA correlano con la durata dell’ipertensione. Maggiore è la durata dell’ipertensione, minore è il punteggio ottenuto nel MoCA.
Dallo studio effettuato è possibile affermare che la metodica della trattografia rende possibile individuare segni precoci di danno cerebrale nell’ipertensione rendendo questo metodo prezioso per identificare nuovi approcci nella prevenzione della demenza vascolare.Hypertension is a public health problem affecting one third of world population according to the latest estimation of World Health Organization and these estimates are increasing considering diagnoses in non-industrialized countries. Hypertension has a long pre-symptomatic phase with initial damage of target organs: heart, kidney, vasculature and brain. Hypertension is the major risk factor for acute diseases such as cerebrovascular accidents and for chronic disease such as neurodegenerative pathologies first vascular dementia. An early phase that can likely lead to dementia, called vascular cognitive impairment, has been observed. Hypertension has been found to affect levels of attention and concentration and secondarily memory since early studies. In routinely clinical practice, assessing cognitive functions in hypertension is not usual and when this happens it is because patients or their families report deficits, an already evident phase of cognitive impairment. The objective of this research project was to assess cognition in hypertensive patients who did not report any damages in cortical white matter and to correlate the cognitive assessment with the MRI-DTI fiber tracking parameters, to identify biomarkers that can predict the future structural damage of the cortex. To pursue this goal, subjects admitted at our outpatients’ facility – Regional Excellence Hypertension Center of the Italian Society of Hypertension, affiliated to the Department of Neurological Complications of Cardiovascular Diseases of I.R.C.C.S. Neuromed - were recruited. All patients who did not report previous damage or neurological diseases and who had no cardiovascular problems except for arterial hypertension were included in the study. After collecting the medical history and the informed consent, patients underwent MRI sequences to exclude those with cerebral cortex damages, then they underwent DTI sequences with the related parameters FA, MD, AD and RD. All recruited patients were subjected to the same procedures: blood pressure measurements, blood collection, ultrasonographic analyses for cardiac and vascular imaging, cognitive assessment. These procedures were necessary to include in this study only subjects with no overt signs of end organ damage or dementia. To this aim tests that could fit the need to better assess cognitive functions in the cardiovascular field were selected: first, MoCA battery of test, considered a diagnostic gold standard tool to evaluate cognition in cardiovascular diseases. Along with this battery, each patient underwent a questionnaire for the autonomy in every day activity (IADL), a learning test, a semantic fluency test and the Stroop test. Results in cognitive assessment showed that hypertensive patients perform worse in MoCA test, in anterograde learning test and in Stroop test compared to control group. Moreover, significant alterations in the parameters of associative (SLF), projection (ATR) and callosal (FMI) fibers emerged from the fiber tracking analyses. These alterations are implicated in executive functions, in memory and in processing information speed. Correlation analyses pointed out the relation between MoCA and both SLF and ATR fibers, MoCA and hypertension duration and Stroop test and FMI fibers. Overall, WM fiber-tracking on MRI make it possible to detect an early marker of damage in hypertension, and in perspective this method could be precious to identify new approaches in preventing vascular dementia.
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Andersson, Jesper, and Nilsson Maria Hedström. ""Dom kallade mig för Dampe och Erik för Hyper men jag tror inte dom menade något negativt" : En retrospektiv undersökning om unga vuxnas upplevelse av resursskola." Thesis, Stockholms universitet, Institutionen för socialt arbete - Socialhögskolan, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-139294.
Повний текст джерелаАнотація:
The purpose of this study was to examine how young adults who have been diagnosed with neuropsychiatric disabilities or other behavioural disorders reflect about the institution (resursskola) and how the institution has affected their identity. Earlier research has shown that categorization of pupils in school leads to deviation. The theoretical approaches were Stigma (Goffman, 1973), Asylums (Goffman, 1973) and a current identity theory. The aim has been to map the respondents’ life history through narrative life stories, and connect them to the context of the examination. Three qualitative semi-structured interviews were analysed using a narrative method, with inspiration from the hermeneutic interpretation model. The material was processed using a narrative content analysis. The themes were structured in chronological order through common themes raised by the respondents. The result shows that taking a student out of their context can cause a double stigmatisation. The respondents’ identities are understood as changing. The study shows that structural and organisational conditions were big influencing factors to the individual’s identity shaping. The result indicates that the institution contributed to stigmatisation and a feeling of alienation in other social environments. But it can also be positive if the respondents can identify themselves with the collective belonging.
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Wasielewski, Sean. "Discrimination of brain-damaged, depressed, and normal subjects using the Woodcock-Johnson tests of cognitive ability-revised." Virtual Press, 1998. http://liblink.bsu.edu/uhtbin/catkey/1117101.
Повний текст джерелаАнотація:
The purpose of this investigation was to examine the validity of the Woodcock Johnson Tests of Cognitive Ability-Revised (WJTCA-R) in discriminating between individuals with neurological or psychiatric impairments and those without known impairment. The primary question was whether WJTCA-R Standard Battery test scores significantly differentiated between individuals with brain-damage (n = 36), depression (n = 21), and without known impairments (n = 32). Archival data obtained for the development of a new neuropsychological assessment measure utilizing the WJTCA-R was analyzed. The results of a discriminant functions analysis indicated that significant differences between the groups existed on the WJTCA-R. Based on WJTCA-R Standard Battery performance alone, participants had a 53% chance of being correctly classified into their diagnostic group. Brain-damaged individuals had the best chance of being correctly classified while correct classification of depressed individuals was only slightly greater than that obtained from random assignment. In addition to moderately supporting the use of a multi-factored, theory-driven assessment instrument, the results of this study have clinical relevance for the development of diagnosis-specific recommendations for brain-damaged and depressed individuals.Department of Educational Psychology
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Скоропад, Ю. І., та Н. Ф. Краткова. "Діагностика заочеревинних гематом у постраждалих з полісистемними пошкодженнями". Thesis, Сумський державний університет, 2013. http://essuir.sumdu.edu.ua/handle/123456789/32576.
Повний текст джерелаАнотація:
Частота заочеревинних гематом при полісистемних пошкодженнях сягає 30-40%, вони найчастіше спостерігаються при тяжких механічних пошкодженнях (ката травмі та дорожно- транспортних пригодах) . При за очеревинних гематомах відбувавається дифузія геморагічної рідини через очеревину, що може хибно діагностуватися як внутрішньо-черевна кровотеча .Традиційні методи діагностики ( УЗД, лапароцентез) дозволяють визначити наявність вільної рідини у черевній порожнині. Діагностичний лапароцентз з перитонеальним лава жом володіє підвищеною чутливістю стосовно інтраабдомінальної кровотечі, геморрагічний характер рідини стає прямим показанням для виконання екстреної лапаротомії, яка заклечається лише у санації і дренуванні черевної порожнини, і сприяє ще більшому погіршенню тяжкого стану постраждалих. Частота невиправданих лапаротомій при заочеревинних гематомах сягає 25-45%
При цитуванні документа, використовуйте посилання http://essuir.sumdu.edu.ua/handle/123456789/32576
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Ahmed, Hesham. "Condition Assessment and Analytical Modeling of Alkali-Silica Reaction (ASR) Affected Concrete Columns." Thesis, Université d'Ottawa / University of Ottawa, 2021. http://hdl.handle.net/10393/42680.
Повний текст джерелаАнотація:
Concrete has proven to be, by far, one of the most reliable materials for the construction of critical infrastructure. However, despite its structural capacity, concrete members are susceptible to damage mechanisms that may decrease its performance and durability throughout its service life. One such mechanism is alkali-silica reaction (ASR), which takes place when unstable siliceous phases present in coarse or fine aggregates react with the alkali hydroxides from the concrete pore solution, generating a secondary product (i.e., ASR gel); this product swells upon moisture uptake from the surrounding environment, leading to cracking and expansion of the affected concrete. In severe cases of ASR-affected infrastructure, structural safety could become a problem, and thus requiring the demolition of affected members. It is, therefore, necessary to adopt effective protocols for the diagnosis and prognosis of aging infrastructure, to ensure its performance over time along with properly planning for rehabilitation strategies, whether required. This work presents a two-stage case study of the S.I.T.E. building at the University of Ottawa for the diagnosis and prognosis of ASR-affected members (i.e., columns) after nearly 20 years in service. The diagnosis phase was conducted with the aim of evaluating the cause and extent of distress and interpreting its impact on the performance of the affected structure. First, a visual inspection was conducted to evaluate potentially damaged members, in order to select the best location for core-drilling. Once ASR was confirmed through petrographic examination, specimens were evaluated through the multi-level assessment (i.e., coupling of microscopic and mechanical assessment). A range of damage was discovered among the examined columns (i.e., 0.03%, 0.05%, and 0.08% expansion). Moreover, evidence of developing freeze and thaw (FT) damage was discovered in columns with greater levels of expansion, raising future concerns regarding the durability and serviceability of members affected by this coupling of damage (i.e., ASR+FT). For the second stage of this project (i.e., prognosis), a novel ASR semi-empirical model was developed with the aim of predicting future ASR-induced expansion and damage in the S.I.T.E. building. The above model was developed and validated (using ASR exposure site data) through the coupling of existing chemo-mechanical macro-models, which were used to predict material behaviour on the structural scale, and novel mathematical relationships for the prediction of anisotropy in the columns. Moreover, the use of the multi-level assessment to predict the mechanical implications of predicted distress was found to enhance the model’s capacity for prognosis and demonstrated important potential for the accurate prediction of multi-level damage in the S.I.T.E. columns.
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Van, Dyke Jason. "Modeling Behaviour of Damaged Turbine Blades for Engine Health Diagnostics and Prognostics." Thèse, Université d'Ottawa / University of Ottawa, 2011. http://hdl.handle.net/10393/20312.
Повний текст джерелаАнотація:
The reliability of modern gas turbine engines is largely due to careful damage tolerant design a method of structural design based on the assumption that flaws (cracks) exist in any structure and will continue to grow with usage. With proper monitoring, largely in the form of periodic inspections at conservative intervals reliability and safety is maintained. These methods while reliable can lead to the early retirement of some components and unforeseen failure if design assumptions fail to reflect reality.
With improvements to sensor and computing technology there is a growing interest in a system that could continuously monitor the health of structural aircraft as well as forecast future damage accumulation in real-time.
Through the use of two-dimensional and three-dimensional numerical modeling the initial goals and findings for this continued work include: (a) establishing measurable parameters directly linked to the health of the blade and (b) the feasibility of detecting accumulated damage to the structural material and thermal barrier coating as well as the onset of damage causing structural failure.
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Smith, Belinda Andrews. "Voice disorders : a handbook for the voice teacher examining the diagnosis, treatment, and rehabilitation of the damaged singing voice." The Ohio State University, 1992. http://rave.ohiolink.edu/etdc/view?acc_num=osu1241190387.
Повний текст джерела
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Kraemer, Peter [Verfasser]. "Schadensdiagnoseverfahren für die Zustandsüberwachung von Offshore-Windenergieanlagen. Damage diagnosis approaches for structural health and condition monitoring of offshore wind energy plants / Peter Kraemer." Siegen : Universitätsbibliothek Siegen, 2011. http://d-nb.info/1017180164/34.
Повний текст джерела
34
Adams, William P. "Thyroid Hormone as a Method of Reducing Damage to Donor Hearts after Circulatory Arrest." VCU Scholars Compass, 2017. http://scholarscompass.vcu.edu/etd/4766.
Повний текст джерелаАнотація:
There is a chronic lack of donor hearts to meet the need for heart transplant both in the US and worldwide. Further, the use of available hearts is limited by the short period between collection and implantation during which the heart can be safely preserved ex vivo. Using mid-thermic Langendorff machine perfusion, we have been able to preserve the metabolic function of a healthy heart for up to 8 hours, twice the limit for current static cold storage. We have also been able to preserve the metabolic function of a damaged DCD Heart collected 30 minutes after cardiac arrest for a period of 8 hours. We further investigated whether it was possible to improve the preservation of DCD heart using treatment with 10 μM Triiodothyronine to stimulate the tissue metabolism and we did find a reduction in damage markers in the treated DCD hearts as compared to the untreated group.
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Behroozinia, Pooya. "Finite Element Analysis of Defects in Cord-Rubber Composites and Hyperelastic Materials." Diss., Virginia Tech, 2017. http://hdl.handle.net/10919/87703.
Повний текст джерелаАнотація:
In recent years, composite materials have been widely used in several applications due to their superior mechanical properties including high strength, high stiffness, and low density. Despite the remarkable advancements in theoretical and computational methods for analyzing composites, investigating the effect of lamina properties and lay-up configurations on the strength of composites still remains an active field of research. Finite Element Method (FEM) and Extended Finite Element Method (XFEM) are powerful tools for solving the boundary value problems. One of the objectives of this work is to employ XFEM as a defect identification tool for predicting the crack initiation and propagation in composites. Another major objective of this study is to investigate the damage development in hyperelastic materials. Two Finite Element models are adopted to study this phenomenon: multiscale modeling of the cord-rubber composites in tires and modeling of intelligent tires for evaluating the feasibility of the proposed defect detection technique.
A new three-dimensional finite element approach based on the multiscale progressive failure analysis is employed to provide the theoretical predictions for damage development in the cord-rubber composites in tires. This new three-dimensional model of the cord-rubber composite is proposed to predict the different types of damage including matrix cracking, delamination, and fiber failure based on the micro-scale analysis. This process is iterative and data is shared between the finite element and multiscale progressive failure analysis. It is shown that the proposed cord-rubber composite model solves the problems corresponding to embedding the rebar elements to the solid elements and also increases the fidelity of numerical analysis of composite parts since the laminate characteristic variables are determined from the microscopic parameters. A tire rolling analysis is then conducted to evaluate the effects of different variables corresponding to the cord-rubber composite on the performance of tires.
Tires operate on the principle of safe life and are the only parts of the vehicle which are in contact with the road surface. Establishing a computational method for defect detection in tire structures will help manufacturers to fix and develop more reliable tire designs. A Finite Element model of a tire with a tri-axial accelerometer attached to its inner-liner was developed and the effects of changing the normal load, longitudinal velocity and tire-road contact friction on the acceleration signal were investigated. Additionally, using the model, the acceleration signals obtained from several accelerometers placed in different locations around the inner-liner of the intelligent tire were analyzed and the defected areas were successfully identified. Using the new intelligent tire model, the lengths, locations, and the minimum number of accelerometers in damage detection in tires are determined. Comparing the acceleration signals obtained from the damaged and original tire models results in detecting defects in tire structures.PHD
36
Beck, Kelley D. "Personality and the prediction of outcome following rehabilitation in persons with acquired brain injuries: The Millon Behavioral Medicine Diagnostic (MBMD)." Thesis, University of North Texas, 2008. https://digital.library.unt.edu/ark:/67531/metadc9121/.
Повний текст джерелаАнотація:
Neuropsychological rehabilitation following acquired brain injury is increasingly recognized as essential with the advancements in research evidence of its effectiveness, particularly as current estimates of disability following the most common forms of brain injury (traumatic brain injury and cerebrovascular accident) are so high. Improvements in predictive capabilities of researchers and clinicians are paramount in designing effective interventions. As many variables associated with outcome following brain injury are not controllable (e.g. severity of the injury, age, education), it is essential that rehabilitation programs design interventions to target those variables that are susceptible to amelioration. While personality factors have been shown to affect outcome in other medical illnesses, only a few studies have examined the influence of personality on outcome following neurorehabilitation for acquired brain injury. The results of these studies have been mixed. This study used the Millon Behavioral Medicine Diagnostic (MBMD) to predict outcome as measured by the Mayo-Portland Adaptability Index (MPAI-4) following brain injury rehabilitation in a heterogeneous sample of persons with acquired brain injuries (N = 50). It was hypothesized that specific coping styles scales from the MBMD (Introversive, Dejected, Oppositional), which are based on Millon's personality system, would predict outcome. Results indicated that both the Introversive and Oppositional coping styles scales accounted for significant amounts of variance in outcome beyond that accounted for by the severity of the injury alone (p < .001). In both cases, individuals with mild/moderate-moderate/severe limitations following completion of the rehabilitation program had significantly higher scores on the Introversive and Oppositional coping compared to individuals with more successful outcomes. The hypothesis that a dejected coping style would predict outcome was not supported. Implications for rehabilitation are discussed in the context of Millon's personality system.
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Fujikake, Tasuku. "Detection of muscle damage by B-mode ultrasonography : relationship between echo intensity and histological changes following injection of bupivacaine to rat hind limb muscles." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2008. https://ro.ecu.edu.au/theses/166.
Повний текст джерелаАнотація:
It is reported that the echo intensity of B-mode ultrasound images increases when human elbow flexors are damaged by eccentric exercise. However, it is unknown what causes the increase in echo intensity, and its relationship to histological changes is unexplored. This study tests the hypothesis that infiltration of inflammatory cells in damaged muscle fibres causes an increase in the echo intensity of B-mode ultrasound images. The study is carried out by injecting bupivacaine hydrochloride (BPVC), which is known to result in infiltration of mononuclear cells, into rat hind limb muscles. This study was approved by the Institutional Animal Research Ethics Committee. BPVC (0.5 % of 0.5 ml) or saline (0.9 % NaCl of 0.5 ml) was injected to the tibialis anterior muscle (TA) of 14-19 wk male Wistar rats (n=12). Ultrasound images were taken from the muscles before, 0, 2, 4, 6, 9, 12, 24, 48, 72, 120, 168, and 336 hours after the injections using a 7.5 MHz probe connected to an Image Point HX® (HP, USA). The images were analysed by an Image J (NIH, USA) to assess the changes in echo intensity of a region of interest, and changes in the intensity were compared between BPVC and controlled conditions. In the subsequent study, the rats (n= 16) were sacrificed before and 0, 2, 6, 12, 24, 48, and 168 hours after BPVC or saline injection into the TA after assessing changes in the echo intensity up to the time of sacrifice in the same time course of the first study. "Histological changes in the muscle after the injection were observed and compared with the ultrasound images. Changes in the echo intensity in the TA after BPVC injection were compared between the control (non and saline injection) and injected limbs by a two-way analysis of variance with repeated measures. The echo intensity did not change significantly in muscles that did not receive an injection. BPVC injection induced greater (P
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Harmouche, Jinane. "Statistical Incipient Fault Detection and Diagnosis with Kullback-Leibler Divergence : from Theory to Applications." Thesis, Supélec, 2014. http://www.theses.fr/2014SUPL0022/document.
Повний текст джерелаАнотація:
Les travaux de cette thèse portent sur la détection et le diagnostic des défauts naissants dans les systèmes d’ingénierie et industriels, par des approches statistiques non-paramétriques. Un défaut naissant est censé provoquer comme tout défaut un changement anormal dans les mesures des variables du système. Ce changement est imperceptible mais aussi imprévisible dû à l’important rapport signal-sur défaut, et le faible rapport défaut-sur-bruit caractérisant le défaut naissant. La détection et l’identification d’un changement général nécessite une approche globale qui prend en compte la totalité de la signature des défauts. Dans ce cadre, la divergence de Kullback-Leibler est proposée comme indicateur général de défauts, sensible aux petites variations anormales cachées dans les variations du bruit. Une approche d’analyse spectrale globale est également proposée pour le diagnostic de défauts ayant une signature fréquentielle. L’application de l’approche statistique globale est illustrée sur deux études différentes. La première concerne la détection et la caractérisation, par courants de Foucault, des fissures dans les structures conductrices. La deuxième application concerne le diagnostic des défauts de roulements dans les machines électriques tournantes. En outre, ce travail traite le problème d’estimation de l’amplitude des défauts naissants. Une analyse théorique menée dans le cadre d’une modélisation par analyse en composantes principales, conduit à un modèle analytique de la divergence ne dépendant que des paramètres du défautThis phD dissertation deals with the detection and diagnosis of incipient faults in engineering and industrial systems by non-parametric statistical approaches. An incipient fault is supposed to provoke an abnormal change in the measurements of the system variables. However, this change is imperceptible and also unpredictable due to the large signal-to-fault ratio and the low fault-to-noise ratio characterizing the incipient fault. The detection and identification of a global change require a ’global’ approach that takes into account the total faults signature. In this context, the Kullback-Leibler divergence is considered to be a ’global’ fault indicator, which is recommended sensitive to abnormal small variations hidden in noise. A ’global’ spectral analysis approach is also proposed for the diagnosis of faults with a frequency signature. The ’global’ statistical approach is proved on two application studies. The first one concerns the detection and characterization of minor cracks in conductive structures. The second application concerns the diagnosis of bearing faults in electrical rotating machines. In addition, the fault estimation problem is addressed in this work. A theoretical study is conducted to obtain an analytical model of the KL divergence, from which an estimate of the amplitude of the incipient fault is derived
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Liu, Zicheng. "Electromagnetic modeling and imaging of damages of fiber-reinforced composite laminates." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLS332.
Повний текст джерелаАнотація:
Mon travail de thèse porte sur la modélisation électromagnétique et l'imagerie de structures périodiques désorganisées. Un certain motif dans une subdivision élémentaire (une "cellule") est répété dans les autres cellules de la structure dans certaines directions de l'espace. Cette répétition est désorganisée par un changement des propriétés des matériaux et/ou géométries des parties constitutives, dans une ou plusieurs cellules. Au premier niveau de modélisation, ces panneaux sont une succession de plaques planes l'une sur l'autre. Chacun se compose d'un agencement linéaire régulier de longs cylindres avec mêmes sections circulaires finies, tous orientés dans la même direction: nous les appelons "fibres", chaque cylindre résultant de l'hypothèse d'un faisceau de fibres de petite taille. Le matériau constitutif des fibres est différent du matériau d'enrobage (matrice) et le renforce. Chaque plaque est constituée de fibres avec différents axes pour assurer la robustesse. Il y a peu ou beaucoup de plaques, avec la répétition d'une petite pile de plaques. Pour les panneaux conducteurs (à base de carbone), l'imagerie est MHz ; pour des panneaux sans pertes ou à faibles pertes (à base de verre), l'imagerie est micro-onde (quelques dizaines de GHz, voire plus, THz). Il pourrait y avoir des cylindres manquants ou déplacés à l'intérieur d'une plaque, avec des changements conséquents dans éventuellement plusieurs cellules, adjacentes ou non. Des dommages locaux peuvent également se produire, entraînant des changements dans la forme ou les propriétés électromagnétiques d'un ou plusieurs cylindres dans une ou plusieurs cellules dans une ou plusieurs plaques. Un caractère aléatoire de la distribution des inclusions pourrait tenir compte des incertitudes de positionnement par rapport aux géométries supposées. Illuminer correctement les structures et la collecte des champs résultant (dans le champ proche espérons-le, peut-être dans le champ lointain) devraient permettre leur imagerie et concourir à leur diagnostic. Ainsi, si une structure périodique sous interrogation est désorganisée, on souhaite imager cette structure tout en prenant soin au mieux de l'information préalable sur la périodicité et la désorganisation, sur les systèmes de détection, et, évidemment, à propos des besoins et des limites de l'essaiMy PhD work is about electromagnetic modeling and imaging of disorganized periodic structures. A certain pattern in an elementary subdivision (a “cell”) is repeated in the other cells of the structure into certain directions of space. This repetition is disorganized by a change of material properties and/or geometries of the constitutive parts, within one or more cells. At first level of modeling, these panels are a succession of planar plates one over the other. Each consists of a regular linear arrangement of long cylinders with same finite circular sections, all orientated into the same direction: we call them “fibers”, each cylinder resulting from the assumption of a bundle of small-size fibers. The constitutive material of the fibers differs from the embedding material (matrix) that they reinforce. Each plate is made of fibers with different axes for sturdiness. There are few or many plates, with repetition of a small stack of plates. For conductive panels (carbon-based), imaging is MHz; for lossless or weakly lossy panels (glass based), imaging is microwave (a few tens GHz, possibly more). There might be missing/displaced cylinders inside a plate, with consequent changes in possibly several cells, adjacent or not. Local damages might occur also, leading to changes in shape or electromagnetic properties of one or more cylinders in one or more cells in one or more plates. Randomness in distribution of the inclusions might account for uncertainties of positioning with respect to assumed geometries. Properly illuminating the structures and collecting the resulting fields (in the near-field hopefully, possibly in the far-field) should allow their imaging and concur to their diagnostics. So, a periodic structure under interrogation is disorganized. One wishes to successfully image the structure while taking care at best of prior information on periodicity and disorganization, on sensing systems, and obviously of needs and limitations of the testing. The PhD benefits from a grant from the Chinese Scholarship Council
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Duchene, Pierre. "Caractérisation non destructive des matériaux composites en fatigue : diagnostic de l’état de santé et pronostic de la durée de vie résiduelle par réseaux de neurones." Thesis, Ecole nationale supérieure Mines-Télécom Lille Douai, 2018. http://www.theses.fr/2018MTLD0008.
Повний текст джерелаАнотація:
Ce travail de recherche consiste en la proposition d’une nouvelle approche de caractérisation non destructive de l’endommagement des matériaux composites (carbone/époxy) sollicités en fatigue par des essais d’auto-échauffement (blocs de chargements croissants). Cette approche est basée sur l’utilisation de plusieurs techniques non destructives appliquées in-situ, en temps réel ou différé, dont l’analyse est, soit redondante soit complémentaire. Au total, six techniques ont été utilisées (émission acoustique, thermographie infrarouge, corrélation d’images numériques, acousto-ultrasons, ultrasons C-scan et ondes de Lamb) et leurs résultats post-traités puis fusionnés à l’aide d’algorithmes basés sur les réseaux de neurones. Les résultats obtenus ont permis d’évaluer et de localiser l’endommagement du matériau et d’estimer sa durée de vie résiduelle. Ce faisant, plusieurs avancés scientifiques ont été obtenus en réalisant, par exemple, une localisation 2D des évènements acoustiques à l’aide seulement de deux capteurs avec une précision millimétrique, ou encore le développement d’une nouvelle technique imagée d’acousto-ultrasons permettant un contrôle hors contraintes de l’état d’endommagement du matériau, …et enfin, le pronostic de la durée de vie résiduelle du matériau basé sur une fusion de données par réseaux de neuronesThis research work consists in a new approach for non-destructive characterisation of damage in composite materials (carbon/epoxy) subjected to fatigue during self-heating tests (increasing load blocks). This approach is based on the use of several non-destructive techniques applied in-situ, in real time or delayed, whose analysis is either redundant or complementary. Six techniques were used (acoustic emission, infrared thermography, digital image correlation, acousto-ultrasound, C-scan ultrasound and lamb waves) and their post-processed results were merged using algorithms based on neural networks. The results obtained made it possible to assess and locate the damage of the material and to estimate its residual life. In doing so, several scientific advances have been obtained by, for example, carrying out a 2D localization of acoustic events using only two sensors with millimetric precision, or the development of a new pictorial acousto-ultrasonic technique allowing an control of the state of material damage at free stress conditions, ... and finally, the prognosis of the residual lifetime of the material based on a data fusion by neural networks
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Kanaan, Mouayad. "Les quartiers non-réglementaires de l'agglomération de Damas : entre les projets urbains et les initiatives des habitants." Thesis, Lyon 3, 2014. http://www.theses.fr/2014LYO30065.
Повний текст джерелаАнотація:
Cette thèse de doctorat repose essentiellement sur notre analyse critique des études et des projets menés par différents consultants (syriens, européens, internationaux) et sur nos enquêtes de terrain à Damas, capitale de la Syrie. En 2004, près de 40 % de la population de l’agglomération de Damas vivaient dans des zones non-réglementaires. Celles-ci représentent donc une composante essentielle de l’expansion urbaine. Premièrement, la thèse analyse le phénomène de l’habitat non-réglementaire à Damas. Elle explique le marché foncier et les caractéristiques des lotissements clandestins dans trois études de cas, deux quartiers: Assad Al Din et Daf Al Chok et un village : Al Bahdalya. Elle montre également comment le maître d’œuvre effectue les étapes de sa construction. Deuxièmement, la thèse traite de la politique urbaine. Elle présente les consultants : MAM, Cities Alliance, Al Diwan, qui ont mené des études et des projets pour les zones étudiées. Elle examine ici leurs études et projets dans une analyse critique approfondie. Troisièmement, la thèse traite de la politique urbaine à l’épreuve des usagers. Elle étudie les caractéristiques socioéconomiques des habitants interviewés des zones étudiées, leur mobilité résidentielle et leurs attitudes à l’égard des projets et des études proposés. Certains des chefs de ménage interviewés pensent qu’ils seront logés, mais beaucoup pensent qu’ils seront expulsés. C'est pourquoi la thèse traite finalement la question du relogement en s’appuyant sur notre enquête de terrain dans une banlieue de relogement Al HussainyahThis dissertation is mainly based on our critical analysis of studies and projects by different consultants (Syrian, European, international) and on our fieldwork in Damascus, capital of Syria. In 2004, nearly 40 % of the population in the urban district of Damascus lived in informal settlements. Therefore, these settlements represent an essential component of urban expansion. Firstly, the dissertation analyzes the phenomenon of informal habitat in Damascus. It explains the land market and the characteristics of illegal settlements in three case studies, two neighborhoods: Assad Al Din and Daf Al Chok and a village: Al Bahdalya. It also shows how the builder performs the different phases of construction. Secondly, the thesis deals with urban policy. It presents the consultants: MAM, Cities Alliance, Al Diwan, who have undertaken studies and projects for the areas mentioned above. Here, the dissertation examines their studies and projects to provide critical, in depth analysis. Thirdly, the dissertation deals with the urban policy as perceived by the citizens. It studies socioeconomic characteristics of the interviewed inhabitants in the areas studied here, residential mobility and their attitudes towards projects and studies proposed to them. Some of interviewed household’s heads think they will be given a house, but many think they will be evicted. That is why the dissertation finally addresses the issue of relocation which is based on our fieldwork in the re-housing suburb of Al Hussainyah
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Sentosa, Bastian Okto Bangkit. "Assessing the structural elements of reinforced concrete buildings by using dynamic measurements." Thesis, Université Grenoble Alpes (ComUE), 2018. http://www.theses.fr/2018GREAA008/document.
Повний текст джерелаАнотація:
Les applications des mesures dynamiques sur les bâtiments existants sont nombreuses : vérification de la vulnérabilité sismique des structures qui ont été construites avant l’apparition des règles parasismiques ; auscultation de la capacité des structures en situation post-sismique ou après des modifications au voisinage (creusement d’un tunnel à côté ou démolition des immeubles voisins par exemple). A l’heure actuelle, ce type de mesure permet le diagnostic d’une structure à l’échelle globale (toute la structure) alors que l’identification et la localisation des endommagements à l’échelle locale (chaque élément de la structure) restent encore à approfondir. Dans le cadre de cette thèse, le diagnostic à l’échelle locale des structures sera étudié. Cette thèse s’insère dans un contexte national de réévaluation des structures existantes du fait du nombre important de bâtiments à réhabiliter. Au sein du LOCIE, nous pensons que le comportement global des bâtiments est certes influencé par l’interaction sol-structure mais au moins autant par la qualité des connexions des éléments de structures entre eux. Il existe un besoin de qualification de ces connexions dont la variabilité du comportement peut provenir aussi bien de défauts de mise en œuvre (positionnement des armatures,…) que du vieillissement des structures. L’objectif principal de cette thèse est de proposer une méthode pouvant caractériser les liaisons entre les éléments de structure afin de pouvoir caler un modèle numérique. Ces caractérisations devaient être possibles à partir de mesures de sollicitations dynamiques. Une première étape de ce travail consistera à caractériser sur une partie de structure une liaison. Cela sera fait sur un portique en béton armé. Par la suite, cette méthode sera adaptée à une caractérisation au sein d’une structure de bâtiment. Pour cela nous ferons appel à la notion de sous-modèle. Un modèle numérique sera associé à cette méthode aussi bien sur la connexion simple que sur l’ensemble du bâtiment. Le travail de thèse s’appuiera sur l’utilisation et le développement de techniques concernant le traitement des données dynamiques ; la réduction de modèles ; l’expérimentation en laboratoire (échelle locale et échelle d’un élément de structure) et la modélisation numérique par éléments finis à plusieurs échellesThere are many of the examples of dynamics measurements applications in the existing building: verification of structural seismic vulnerability, which was constructed before the earthquake building code; auscultation of structural capacity in post-earthquake situation or after modification in surround environment (Excavation of tunnel or demolition the neighbour buildings for example). Currently, this measurement type enables the diagnosis a structure in global scale (a whole structure) while identification and localization of damage in local scale (each elements of the structure) remains to be explored. In this dissertation, diagnosis in locale scale will be studied. This study is significant for its contribution to the national reassessment of existing structures where there is the large number of buildings to be rehabilitated
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Kodjo, Apedovi. "Contribution à la caractérisation des bétons endommagés par des méthodes de l'acoustique non linéaire. Application à la réaction alcalis-silice." Thèse, Université de Sherbrooke, 2008. http://savoirs.usherbrooke.ca/handle/11143/1839.
Повний текст джерелаАнотація:
Cette thèse apporte une nouvelle contribution à la caractérisation non destructive des matériaux en béton endommagés par la réaction alcalis-silice (RAS). À cette fin, des techniques et outils de caractérisation non linéaire ont été mises au point. Un banc de test de résonance non linéaire a été développé. Des améliorations ont été apportées au niveau de la chaine d'excitation et au niveau du traitement du signal afin d'optimiser la sensibilité du banc de test. Les essais non linéaires ont été effectues sur sept échantillons de béton endommagés par la RAS, trois échantillons de béton endommagés thermiquement, deux échantillons de béton endommagés mécaniquement et trois échantillons de béton sains. La non-linéarité comportementale des matériaux étant souvent attribuée au comportement hystérétique des micro-défauts contenus dans ces derniers, il a été montré dans un premier temps, que le béton endommagé par la RAS présente un comportement hystérétique. Cette étude a été faite à partir des essais de l'acousto-élastique. Le banc de test de résonance non linéaire a été ensuite utilisé pour la caractérisation des bétons sains et endommagés par la RAS. II a été montré que la technique non linéaire, en plus de permettre une caractérisation sans avoir l'historique de l'état du matériau, permet également de détecter de façon précoce l'endommagement du matériau réactif. L'influence de la teneur en eau sur les paramètres non linéaires a également été étudiée. II a été montré que les valeurs mesurées sur des échantillons de béton conservés dans des conditions de forte teneur en eau sont plus faibles. Dans l'objectif de trouver une particularité à l'endommagement causé par la RAS, la nature visqueuse du gel produit par la RAS a été utilisée. Une démarche, qui s'inspire des essais de fluage en statique réalisés sur des matériaux, a été utilisée pour répondre à cette question de signature de la RAS, tout en appliquant la technique de résonance non linéaire. Le modèle ressort-amortissement de Maxwell a été utilise pour l'interpretation des résultats. Ainsi, le temps de réponse au fluage a été analysé sur des échantillons endommagés par la RAS. II en ressort que le gel issu de la RAS rallonge le temps de réponse au fluage. Enfin, les limites de la technique de résonance non linéaire pour une application in situ ont été expliquées et une nouvelle technique non linéaire estimée applicable sur site a été initiée. Cette technique consiste à utiliser une source externe telle une masse pour provoquer la non-linéarité dans le matériau, pendant qu'une onde ultrasonore sonde le milieu.||The aim of this thesis is to contribute to the non-destructive characterization of concrete materials damaged by alkali-silica reaction (ASR). For this purpose, some nonlinear characterization techniques have been developed, as well as a nonlinear resonance test device. In order to optimize the sensitivity of the test device, the excitation module and signal processing have been improved. The nonlinear tests were conducted on seven samples of concrete damaged by ASR, three samples of concrete damaged by heat, three concrete samples damaged mechanically and three sound concrete samples. Since, nonlinear behaviour of the material is often attribute to its micro-defects hysteretic behaviour, it was shown at first that concrete damaged by ASR exhibits an hysteresis behaviour. To conduct this study, an acoustoelastic test was set, and then nonlinear resonance test device was used for characterizing sound concrete and concrete damaged by ASR. It was shown that the nonlinear technique can be used for characterizing the material without knowing its initial state, and also for detecting early damage in the reactive material. Studies were also carried out on the effect of moisture regarding the nonlinear parameters; they allowed understanding the low values of nonlinear parameters measured on concrete samples that were kept in high moisture conditions. In order to find a specific characteristic of damage caused by ASR, the viscosity of ASR gel was used. An approach, based on static creep analysis, performed on the material, while applying the nonlinear resonance technique. The spring-damping model of Maxwell was used for the interpretation of the results. Then, the creep time was analysed on samples damaged by ASR. It appears that the ASR gel increases the creep time. Finally, the limitations of the nonlinear resonance technique for in situ application have been explained and a new applicable nonlinear technique was initiated. This technique use an external source such as a mass for making non-linearity behaviour in the material, while an ultrasound wave is investigating the medium.
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Архипов, О. Г., О. Г. Боярчук та Д. О. Ковальов. "Розробка приладу на основі імпульсного методу контролю корозійно-механічних пошкоджень обладнання". Thesis, Видавництво СумДУ, 2012. http://essuir.sumdu.edu.ua/handle/123456789/27705.
Повний текст джерелаАнотація:
Метою роботи була розробка логічної блок-схеми імпульсного методу постійного моніторингу корозійно-механічних пошкоджень обладнання у реальному часі.
При цитуванні документа, використовуйте посилання http://essuir.sumdu.edu.ua/handle/123456789/27705
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Dornic, Nausicaa. "Élaboration et comparaison de deux modèles de durée de vie des fils d’interconnexion des modules de puissance, l’un basé sur les déformations et l’autre sur les dégradations." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLN043/document.
Повний текст джерелаАнотація:
Dans de nombreux domaines, tels que l’industrie des transports ou bien des infrastructures, la tendance est à l’introduction toujours plus importante d’équipements électriques. De ce fait, les industriels sont de plus en plus confrontés à la nécessité de fournir des dispositifs robustes et fiables avec un minimum de maintenance. Les composants électroniques, tels que les transistors IGBTs ou MOSFETs et les diodes rassemblés dans des modules de puissance, sont au cœur de la conversion d'énergie électrique. En conséquence, ils sont soumis en opération à de fortes contraintes environnementales et fonctionnelles (température, humidité…). L’ensemble de ces contraintes a un impact sur la durée de vie des composants, et donc sur la fiabilité des dispositifs. D’un point de vue économique, le remplacement d’un équipement défectueux est moins pénalisant qu’une défaillance brutale du système. Ainsi, l’utilisation d’outils de diagnostic est nécessaire pour prédire la durée de vie restante des dispositifs en opération, et mettre en place une maintenance adaptée et efficace.Pour déterminer la durée de vie restante des modules de puissance en opération, des modèles de durée de vie sont utilisés. La plupart de ces modèles sont établis soit de manière empirique, soit de manière physique, soit de manière statistique. Les modèles empiriques sont les plus courants, car leur réalisation et implémentation sont maintenant bien connues. Ils se basent sur des résultats issus de tests de cyclage accélérés qui reproduisent les contraintes endurées par le module de puissance sous des conditions "accélérées" de fonctionnement. Une extrapolation est ensuite nécessaire pour obtenir l’état de santé du dispositif dans des conditions normales de fonctionnement. Le principal inconvénient de ces modèles réside dans le manque de description des mécanismes physiques responsables de l’endommagement. Ce manque peut mener potentiellement à des erreurs, notamment lors de l’extrapolation. C’est pourquoi les modèles basés sur la physique connaissent un intérêt grandissant.Dans cette thèse, deux modèles de durée de vie basés sur la physique et appliqués aux modules de puissance IGBTs sont proposés et comparés. La première approche est basée sur les déformations induites à l’intérieur de l’assemblage du module lorsque soumis à des contraintes thermiques. Dans ce cas, la dégradation est décrite via la quantification des déformations pour un stress thermique donné. Dans la seconde approche, le modèle de durée de vie est basé directement sur l’endommagement via l’établissement d’un modèle de dégradation. La comparaison des deux modèles met en lumière les défauts et qualités de chacun. D’une manière plus générale, l’établissement et la comparaison de ces modèles s’inscrit dans une démarche de développement d’outils de diagnostic afin de prédire la durée de vie restante des modules de puissance en opérationThe domain of power electronics reliability has become an important center of interest with the recent massive system electrification. The manufacturers are more and more confronted to the necessity of producing reliable devices with optimized maintenance. Electronics components, such as IGBTs, diodes and MOSFETs assembled in power modules, are at the center of the systems conversion, and as a consequence, are subjected to high environmental and functional stresses (ambient temperature, vibrations…). All these factors have a strong impact on the components lifetime and thus on the devices reliability. Economically, scheduling a maintenance with a system replacement is less detrimental than a brutal failure of the system. As a consequence, the use of lifetime prognostic tools is necessary. The problematic consists in the health state prediction of power modules in functioning to be able to schedule a maintenance before the failure of the equipment.To be able to determine the remaining useful lifetime of power modules in functioning, lifetime models are used. These models can either be empirical, physical or statistical. The empirical models are the most common ones, because of their easy establishment and implementation. They are based on results from accelerated power cycling tests, which reproduce the stresses endured by the power modules in severe conditions. An extrapolation is then needed to obtain the power module health state in normal functioning conditions. The main drawback of these models is the lack of description of the physical mechanisms leading to damage, resulting potentially in errors in particular during extrapolation. That’s the reason why physical models start to draw more attention.In the thesis, two physical lifetime models of IGBT power modules are proposed. The first approach is based on deformation induced inside the device assembly in operation. The degradation is in this case described by the quantification of deformation related to thermal stresses. In the second approach, the lifetime model is based directly on damage through the establishment of a degradation model. These two lifetime models are finally compared to show the benefits and disadvantages of each. More generally, the establishment and comparison of these models is part of an approach to develop diagnostic tools so that the remaining useful lifetime of power modules can be predicted in operation
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Gousseau, William. "Pronostic de dégradation d'endommagements de roulements sur application aéronautique par analyse vibratoire." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSEI063.
Повний текст джерелаАнотація:
Dans le cadre d’une maintenance préventive de ses moteurs, Safran Aircraft Engines souhaite compléter ses opérations de diagnostic par un pronostic fiable de la durée de vie résiduelle des roulements. Suite à une agression, il y a actuellement une grande incertitude sur la durée de vie restante avant défaillance du roulement à partir du seuil d’observabilité vibratoire de l’endommagement. Les algorithmes actuels diagnostiquent un stade de dégradation approximatif et génèrent des messages d’alarme de différents niveaux, chaque niveau correspondant à un stade de dégradation différent, mêlant confiance et sévérité du diagnostic. Un aspect important du pronostic est la prise en compte des paramètres contextuels influant sur la vitesse de dégradation. Les objectifs de cette thèse sont de disposer de méthodes et d’outils permettant de quantifier un temps de fonctionnement restant avant défaillance de roulement en regard : - de la gravité de l’endommagement détecté, - des conditions environnementales de fonctionnement, - de la profondeur de pronostic souhaitée, Les contraintes industrielles associées à ces objectifs sont les suivantes : 1) Le pronostic devra être basé, a minima, sur des mesures vibratoires hautes fréquences de quelques kHz (accéléromètres ou microphones), des données contextuelles (les régimes de rotation des différents rotors, par exemple, ou encore les amplitudes des niveaux pilotés sur les régimes de rotation, révélateurs d’un chargement des paliers) 2) .Constituer une base de données d’essais issus d’un plan d’expériences : ces essais devront tenir compte des contraintes liées à la maîtrise des paramètres jugés significativement influents 3) Cette base de données devra prendre en compte la représentativité de l’environnement vibratoire d’un moteur d’avion. 4) Proposer un outil ou une méthode de pronostic en tenant compte de la nature du roulement à considérerAs part of preventive maintenance of its engines, Safran Aircraft Engines wishes to complete its diagnostic operations with a reliable prognosis of the residual life of the bearings. Following an attack, there is currently a great deal of uncertainty about the remaining life before bearing failure from the threshold of vibrational observability of the damage. Current algorithms diagnose an approximate stage of degradation and generate alarm messages of different levels, each level corresponding to a different stage of degradation, combining confidence and severity of diagnosis. An important aspect of the prognosis is the taking into account of the contextual parameters influencing the rate of degradation. The objectives of this thesis are to have methods and tools to quantify a running time remaining before bearing failure with regard to: - the severity of the damage detected, - the environmental conditions of operation, - the depth The industrial constraints associated with these objectives are as follows: 1) The prognosis should be based, at least, on high-frequency vibratory measurements of a few kHz (accelerometers), contextual data (the rotational speeds of the different rotors, for example, or the amplitudes of the levels piloted on them), rotation regimes, revealing a loading of the bearings) 2). Constituing a database of tests resulting from a plan of experiments: these tests will have to take into account the constraints related to the control of the parameters considered to be significantly influential 3) This database must take into account the representativity of the vibratory environment of an aircraft engine. 4) Propose a tool or method of prognosis taking into account the nature of the bearing to consider
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DAGA, ALESSANDRO PAOLO. "Vibration Monitoring: Gearbox identification and faults detection." Doctoral thesis, Politecnico di Torino, 2019. http://hdl.handle.net/11583/2763473.
Повний текст джерела
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Sampson, Dayle Lorand. "Urinary biomolecular indicators of exercise-induced over exertion injury." Thesis, Queensland University of Technology, 2013. https://eprints.qut.edu.au/62158/1/Dayle_Sampson_Thesis.pdf.
Повний текст джерелаАнотація:
Poor health and injury represent major obstacles to the future economic security of Australia. The national economic cost of work-related injury is estimated at $57.5 billion p/a. Since exposure to high physical demands is a major risk factor for musculoskeletal injury, monitoring and managing such physical activity levels in workers is a potentially important injury prevention strategy. Current injury monitoring practices are inadequate for the provision of clinically valuable information about the tissue specific responses to physical exertion.
Injury of various soft tissue structures can manifest over time through accumulation of micro-trauma. Such micro-trauma has a propensity to increase the risk of acute injuries to soft-tissue structures such as muscle or tendon. As such, the capacity to monitor biomarkers that result from the disruption of these tissues offers a means of assisting the pre-emptive management of subclinical injury prior to acute failure or for evaluation of recovery processes.
Here we have adopted an in-vivo exercise induced muscle damage model allowing the application of laboratory controlled conditions to assist in uncovering biochemical indicators associated with soft-tissue trauma and recovery. Importantly, urine was utilised as the diagnostic medium since it is non-invasive to collect, more acceptable to workers and less costly to employers. Moreover, it is our hypothesis that exercise induced tissue degradation products enter the circulation and are subsequently filtered by the kidney and pass through to the urine.
To test this hypothesis a range of metabolomic and proteomic discovery-phase techniques were used, along with targeted approaches. Several small molecules relating to tissue damage were identified along with a series of skeletal muscle-specific protein fragments resulting from exercise induced soft-tissue damage. Each of the potential biomolecular markers appeared to be temporally present within urine. Moreover, the regulation of abundance seemed to be associated with functional recovery following the injury. This discovery may have important clinical applications for monitoring of a variety of inflammatory myopathies as well as novel applications in monitoring of the musculoskeletal health status of workers, professional athletes and/or military personnel to reduce the onset of potentially debilitating musculoskeletal injuries within these professions.
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El, Bizri Rana. "Characterization of Pten and Trp53 deficient prostatic tumors in mice." Thesis, Strasbourg, 2018. http://www.theses.fr/2018STRAJ097.
Повний текст джерелаАнотація:
Le cancer de la prostate est la forme de cancer la plus fréquente et la troisième cause de décès par cancer chez l’homme dans les sociétés occidentales. Alors que la plupart des cancers de la prostate localisés sont éradiqués chirurgicalement, la plupart des tumeurs métastatiques répondant initialement aux thérapies par privation d’androgènes deviennent résistantes au traitement, causant généralement le décès du patient. Les gènes suppresseurs de tumeur PTEN et p53 étant fréquemment mutés dans les cancers de la prostate métastatiques et résistants à la castration, le laboratoire d’accueil a généré des modèles murins dans lesquels Pten et/ou Trp53 sont sélectivement invalidés à l’âge adulte dans les cellules épithéliales prostatiques dans le but de déterminer les évènements clés conduisant à la progression du cancer de la prostate. Notre étude révèle que l’invalidation de PTEN stimule la prolifération des cellules épithéliales prostatiques et conduit à des néoplasmes prostatiques intraépithéliaux en quelques mois. Cette hyper-prolifération induit un stress réplicatif et une réponse aux dommages de l’ADN qui va conduire à un arrêt progressif de la croissance cellulaire et une entrée en sénescence. Les cellules sénescentes sécrètent de nombreuses cytokines et de chimiokines, et peuvent accumuler des mutations contribuant ainsi à la progression de la tumeur. Il est notable qu’en l’absence de Trp53, les épithéliums prostatiques dépourvus de Pten développent des néoplasmes prostatiques intraépithéliaux entrant en sénescence. Cependant, la formation d’adénocarcinomes est accélérée et des tumeurs sarcomatoïdes pouvant générer à long terme des métastases apparaissent. En l’absence de Pten, certaines cellules épithéliales prostatiques perdent leur identité moléculaire en exprimant des marqueurs caractéristiques de cellules souches et différenciation neuroendocrinienne. Nous avons également mis en évidence des cellules épithéliales prostatiques déficientes en PTEN et p53 résistantes à la castration exprimant à la fois des marqueurs de cellules basales et luminales. En conclusion, nos travaux ont permis une avancée dans la compréhension des mécanismes conduisant à des formes incurables de cancer de la prostate. Les traitements actuels ayant des effets secondaires importants et pouvant générer des résistances, le développement de nouvelles stratégies thérapeutiques permettant l’élimination des cellules sénescentes mais aussi des cellules épithéliales prostatiques exprimant des marqueurs de cellules basales et luminales dans les lésions précancéreuses représente des perspectives intéressantes pour traiter le cancer de la prostateProstate cancer (PCa) is a leading cause of male cancer death worldwide. While most locally PCa are curable, metastatic tumors initially respond to androgen deprivation therapy but ultimately relapse to castration-resistant prostate cancer (CRPC), which is a lethal disease. Since the tumor suppressor genes PTEN and p53 are frequently mutated in metastatic and CRPC, the host laboratory generated mouse models in which Pten and/or Trp53 are selectively ablated in adult prostatic epithelial cells (PECs) in order to unravel the key events leading to prostate cancer progression. Our study reveals that Pten ablation stimulates PECs proliferation forming prostatic intraepithelial neoplasia (PIN) within a few months. This hyper-proliferation induces replicative stress and a DNA damage response (DDR), which in turn leads to a progressive growth arrest with characteristics of cell senescence. As senescent cells secrete a large number of cytokines and chemokines, and can accumulate other mutations, they might contribute to tumor progression. Importantly, in the absence of Trp53, most Pten-null PECs develop PINs that enter senescence. However partial loss of PECs identity is detected as we show enhanced stemness and focal neuroendocrine differentiation of luminal Pten-null PECs. In some cases, adenocarcinoma and sarcomatoid tumors are formed, and more than one-third of the latter develop metastases. Strikingly, we also show formation of a castrate-resistant cell entity of both Pten and Pten/Trp53-null PECs sharing luminal and basal markers. Taken together, as current treaments lead to side effects and resistance, the development of therapeutic strategies to eliminate senescent cells/and or PECs expressing luminal and basal/stem progenitor in pre- cancerous lesions represents promising option for prostate cancer treatment
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Chang, Lu-Chen, and 張育誠. "Damage Diagnosis of Brushless DC Motors." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/67768970046226817838.
Повний текст джерелаАнотація:
碩士中原大學
電機工程研究所
102
Due to the worse air pollution and the use-cost raising of fuel vehicles, the vehicles manufacturers focus the research and development of electric vehicles (EV). This thesis is using analyzing motor current signal as a research to diagnosis the motor bearing and the winding faults to prevent or reduce the motor fault probability of EV. In the thesis, an automatic diagnosis system for a brushless DC motor (BLDC) fault is established. First, considering different motor damage kinds, as bearings and windings, the system measured the motor current signal in normal and fault operating. Then, three signal processing methods, as the wavelet multi-resolution analysis (MRA), the intrinsic mode function (IMF) and the Hilbert-Huang transform (HHT), were used to analyze the motor current signal. Besides, artificial intelligent algorithms, as back-propagation neural network (BPNN) and K-nearest neighbor (KNN), were used to identify motor current signals. Second, an algorithm method combine the K-means clustering algorithm with the artificial bee colony algorithm (ABC) was proposed to select best feature by calculating the correlation between features and data. So that, a example using UCI database to verify feature selection method would be reduce the dimension of features. Finally, a noise test was added to obtain the noise resistance of the classification system. As results, the motor current signal using HHT would correctly identify various motor fault kinds. Otherwise, it would improve the accuracy drop problem of the classification system by feature selection strategy in the noise environment. Summary, the use of HHT for motor faults had better performance and the proposed feature selection method increased the noise tolerance of the classification system.