Computational uncertainity quantification in pressure-driven fracture processes

Tesi en modalitat de cotutela Universitat Politècnica de Catalunya i Eindhoven University of TechnologyUncertainty quantification is important in assessing and predicting the performance of complex engineering systems and processes, especially in the absence of adequate experimental or real-world data. With the increase in computing power, computational uncertainty quantification is playing an increasingly important role in decision making processes. We have studied the application of uncertainty quantification to pressure-driven fracture processes, which are surrounded by uncertainty as data are typically scant and available models are often rudimentary. In this dissertation we have developed a computational framework that combines simulation techniques for pressure-driven fracturing processes with state-of-the-art uncertainty quantification techniques. On the one hand, the framework simulates the influence of uncertainties in, for example, formation data, on quantities of interest such as the fracture length. On the other hand, the uncertainty quantification framework allows us to incorporate indirect measurement data, such as well pressures, in the simulation procedure. The developed computational uncertainty quantification framework improves the understanding of the influence of uncertainties on pressure-driven fracture processes.La cuantificación de la incertidumbre es importante para evaluar y predecir el desempeño de complejos sistemas y procesos de ingeniería, especialmente en ausencia de un mundo experimental o real adecuado datos. Con el aumento de la potencia informática, la cuantificación de la incertidumbre computacional está jugando un papel cada vez más importante en los procesos de toma de decisiones. Hemos estudiado la aplicación de cuantificación de la incertidumbre a los procesos de fractura por presión, que están rodeados de incertidumbre como los datos suelen ser escasos y los modelos disponibles son a menudo rudimentarios. En esta disertación hemos desarrollado un marco computacional que combina simulación. Técnicas para procesos de fractura por presión con cuantificación de incertidumbre de vanguardia técnicas Por un lado, el marco simula la influencia de las incertidumbres en, por ejemplo, datos de formación, sobre cantidades de interés como la longitud de la fractura. Por otro lado, la incertidumbre. El marco de cuantificación nos permite incorporar datos de medición indirecta, como también presiones, en el procedimiento de simulación. El marco de cuantificación de incertidumbre computacional desarrollado mejora la comprensión de la influencia de las incertidumbres en los procesos de fractura por presión.Postprint (published version

Belching on exertion - coronary artery disease

Belching is a ubiquitous symptom in clinical practice. It could be due to gastrointestinal disease or behavioral, functional and physiological causes. It’s association with acute myocardial infarction, more frequently, with inferior myocardial infarction, has been well established. But exertional belching as a cardinal symptom of coronary artery disease is not well documented and its presence is not mentioned in any standard textbooks. It is rarely reported in the literature. Here we present a female diabetic, who presented with exertional belching as a lone complaint. She was confirmed to have significant coronary artery disease necessitating an intervention. So it may be prudent if clinicians are aware of the fact that exertional belching could be of cardiac origin and needs further evaluation and intervention

Pregnancy in Takayasu arteritis - maternal and fetal outcome

Background: Takayasu arteritis is a rare medical disorder of primary vasculitis of unknown etiology. It affects reproductive age women. It is rare disease and associated with serious maternal and fetal complications and long term morbidity.Methods: Retrospective analysis of patients with diagnosed Takayasu arteritis, to know the impact of disease on maternal status and evaluate fetal outcome. The objective of this study was to know the maternal and fetal outcome in pre-diagnosed cases of Takayasu arteritis. The necessity of accurate measurement of pulse and blood pressures in all the limbs in a suspected case of hypertension in antenatal women at any period of gestation and TYPE the disease accordingly. 3. To evaluate the typing of TA on maternal and fetal outcome.Results: All the 4 patients with TA had medical complication like hypertension in the form of chronic hypertension and pre eclampsia that needed good monitoring of BP in all 4 limbs.Conclusions: As the typing of disease increased, more medical and obstetric complications were noticed

METHODS AND APPARATUS FOR INTENT AND CONTEXT-BASED AD-HOC DATA DRIVEN REPORTING AND VISUALIZATION

Existing executive events, investment planning sessions, regular checkups, service reviews, etc. are mainly based on static content such as templates, PDF files and PPT presentations. However, these templates have static dashboard and predefined scenarios that cannot be changed/altered during the presentation and lack the ability to visually-represent relevant ad-hoc content. As such, presented herein are dynamic (ad-hoc) and context-based visualization systems that are more intuitive than conventional arrangements. The techniques presented herein may, for example, facilitate a more natural decision making process by providing content that can dynamically change based, for example, on the current context, such as important in-depth questions supporting a decision making process, etc. In one example, a user may ask a follow up question and the system is configured to store the context and provide a recursive answer. The system may offer the next best question, based on an embedded convolutional sequence. The techniques presented herein may also use generative models and graph classifiers to convert data into a visual representation

The utility of handheld and wearable devices in the diagnosis of cardiac arrhythmias

The aim of this thesis is to highlight the existing body of literature on the utility of wearable and handheld devices in the diagnosis and management of cardiac arrhythmias. Furthermore, the thesis investigates the accuracy and utility of the AliveCor Kardia for the detection of cardiac arrhythmias in a systematic fashion

Clinical presentation of tubal ectopic pregnancy

Background: When the fertilized ovum gets implanted at site other than normal position of uterine cavity, it is known as ectopic pregnancy. Incidence of ectopic pregnancy is 1-2% of all reported pregnancies. It is an unmitigated disaster of human production and the most important cause of morbidity and mortality in first trimester with major cause of reduced child bearing potential. It is notorious in its clinical presentation, challenging the attending physician.Methods: women with risk factors, signs and symptoms and with confirmed diagnosis. Women discharged against medical advice. Study population is 50. Retrospective analysis for 3 years (2016-2019). Objectives of this study were to study the incidence, risk factors, clinical presentation, diagnosis and changing trends of modern management. Results analysed after entering the information in the excel sheets using descriptive analysisResults: Out of 4940 deliveries, 50 were tubal ectopic pregnancies 1.012%. Women aged 20-25 years were 52%. In our study, multiparous were 68%. Common symptoms were abdominal pain 80.2%, amenorrhea 72%, urine gravindex test positive 92.8%. Etiology was PID 20%, previous ectopic pregnancy 4%, IUCD 4%, LSCS with tubectomy 16%, most common site is ampulla 82%. About 78% were ruptured. Tubal abortions 4%, salpingectomy done in 82%. Laparotomy in 2.43% in hemodynamically unstable. Medical management 8%. Salpingostomy in 4% and expectant management 2%. Morbidity in the form of blood transfusion 23.48%, DIC with ICU admission 2%. No mortality.Conclusions: A high index of clinical suspicion with underlying risk factors may get us early diagnosis for timely intervention

Chubby mothers-maternal and perinatal outcome in high body mass index

Background: Obesity is a state of excess adipose tissue mass. Body mass index (BMI) is a crucial predictor of nutritional status of pregnant women. High BMI may lead to various adverse maternal and perinatal outcomes. This study is designed to see the effect of maternal BMI on pregnancy outcome and perinatal outcome according to Asian standards.Methods: This is an institutional retrospective, descriptive study of 100 pregnant women conducted in the department of obstetrics and gynaecology of a rural tertiary centre Dr. PSIMS and RF, Chinaoutpalli, Gannavaram, Vijayawada, AP, India from June 2017 to July 2019.Results: It was observed that as BMI increased risk of complications increased like hypertension disorders in pregnancy, gestational diabetes mellitus, preterm labour. Also risk of macrosomia, operative delivery, Neonatal intensive care unit (NICU) admissions increased.Conclusions: As maternal BMI is a good predictor has strong correlation with pregnancy complications and outcomes, measures should be taken to motivate for pre pregnancy counselling regarding weight management and close surveillance in antenatal period to diagnose at the earliest any complications

Analogue-based approaches in anti-cancer compound modelling: the relevance of QSAR models

Background: QSAR is among the most extensively used computational methodology for analogue-based design. The application of various descriptor classes like quantum chemical, molecular mechanics, conceptual density functional theory (DFT)- and docking-based descriptors for predicting anti-cancer activity is well known. Although in vitro assay for anti-cancer activity is available against many different cell lines, most of the computational studies are carried out targeting insufficient number of cell lines. Hence, statistically robust and extensive QSAR studies against 29 different cancer cell lines and its comparative account, has been carried out. Results: The predictive models were built for 266 compounds with experimental data against 29 different cancer cell lines, employing independent and least number of descriptors. Robust statistical analysis shows a high correlation, cross-validation coefficient values, and provides a range of QSAR equations. Comparative performance of each class of descriptors was carried out and the effect of number of descriptors (1-10) on statistical parameters was tested. Charge-based descriptors were found in 20 out of 39 models (approx. 50%), valency-based descriptor in 14 (approx. 36%) and bond order-based descriptor in 11 (approx. 28%) in comparison to other descriptors. The use of conceptual DFT descriptors does not improve the statistical quality of the models in most cases. Conclusion: Analysis is done with various models where the number of descriptors is increased from 1 to 10; it is interesting to note that in most cases 3 descriptor-based models are adequate. The study reveals that quantum chemical descriptors are the most important class of descriptors in modelling these series of compounds followed by electrostatic, constitutional, geometrical, topological and conceptual DFT descriptors. Cell lines in nasopharyngeal (2) cancer average R2 = 0.90 followed by cell lines in melanoma cancer (4) with average R2 = 0.81 gave the best statistical values

Study on HELLP syndrome - maternal and perinatal outcome

Background: HELLP Syndrome is a serious obstetric complication in pregnancy characterised by haemolysis, elevated liver enzymes and low platelet count. Incidence is 0.5-0.9% of all pregnancies and in 10-20% of cases with severe preeclampsia and eclampsia. The aim of the study was to study the incidence, different clinical presentations and diagnosis of HELLP syndrome in Pre eclampsia and Eclampsia and to analyze the severity, complications, maternal and perinatal outcome.Methods: It is a 16 months period retrospective study of 102 cases of preeclampsia and eclampsia admitted in NRIMC and GH in OBGY Department with more than 28 weeks gestation. Of these, 91 cases had preeclampsia and 11 cases had eclampsia. Out of these, 15 cases developed HELLP Syndrome. The available history, clinical data, detailed laboratory investigations were studied and categorized by Mississippi classification for better analysis of complications and outcome in HELLP syndrome.Results: Of 91 cases of Preeclampsia, 12 cases (13.18%) developed HELLP syndrome and out of 11 cases of Eclampsia, 3 cases (27.27%) had HELLP Syndrome. Majority of the cases belonged to 21-25years age group and were mostly from lower Socio economic status. The present study showed 60% maternal morbidity and 6.6% maternal mortality and the perinatal morbidity and mortality was 46.6% each.Conclusions: HELLP Syndrome is a severe variant and a dreadful complication of Preeclampsia and Eclampsia, it needs early diagnosis and timely intervention in the form of termination of pregnancy to arrest further progress of pathophysiology leading to complications

A Proper Generalized Decomposition (PGD) approach to crack propagation in brittle materials: with application to random field material properties

Understanding the failure of brittle heterogeneous materials is essential in many applications. Heterogeneities in material properties are frequently modeled through random fields, which typically induces the need to solve finite element problems for a large number of realizations. In this context, we make use of reduced order modeling to solve these problems at an affordable computational cost. This paper proposes a reduced order modeling framework to predict crack propagation in brittle materials with random heterogeneities. The framework is based on a combination of the Proper Generalized Decomposition (PGD) method with Griffith’s global energy criterion. The PGD framework provides an explicit parametric solution for the physical response of the system. We illustrate that a non-intrusive sampling-based technique can be applied as a postprocessing operation on the explicit solution provided by PGD.We first validate the framework using a global energy approach on a deterministic two-dimensional linear elastic fracture mechanics benchmark. Subsequently, we apply the reduced order modeling approach to a stochastic fracture propagation problem