A Hybrid Numerical Method for 3D Multiphysics Modeling of Ultrasonic Transit-Time Flowmeters : Including Sound Propagation in Real Pipe Flows

Ultralyd mengdemålere av typen Ultrasonic Transit-Time Flowmeters (UTTF) og deres modellering er hovedfokus i denne avhandlingen. UTTF kan kategoriseres i clamp-on og inline-målere avhengig av behovene til applikasjoner for mengdemåling. Simuleringer, studier og eksperimentell verifisering av inline-målere med høye krav til nøyaktighet utføres i dette arbeidet. Det er demonstrert at ved bruk av simuleringer er det mulig å akselerere innovasjon, samt å kontinuerlig forbedre målenøyaktighet og teknologi for det raskt voksende markedet for UTTF. I denne avhandlingen foreslås en multifysikk, hybrid numerisk metode, dvs. en kombinasjon av en Finite Element Method (FEM) og en Finite Volume Method (FVM), for 3D-simuleringer og undersøkelse av fysiske fenomener som påvirker oppførselen til UTTF. Den utviklede metoden, ’Simulations of Piezoelectricity, Acoustics, Coupled with CFD’ (SimPAC2), brukes som et designverktøy for UTTF, samt for å forbedre forståelsen av virkemåten av UTTF. For simuleringen er UTTF delt inn i to deler, og den respektive, mer passende metoden brukes for hver del. Konkret brukes FEM for simulering av piezoelektrisitet og strukturell akustikk i de faste delene, dvs. transduserne og om ønskelig, delvis i målerøret. FEM brukes også til simulering av bølgeutbredelse i deler av mediet. Akustikk og simulasjoner ved Computational Fluid Dynamics (CFD) vurderes i mediet, samt deres interaksjon med hverandre ved bruk av FVM, som tradisjonelt er mer passende for CFD og store simuleringer som trenger sterk parallellisering. Den hybride SimPAC2-metoden krever komplekse grensesnitt mellom FEM- og FVM-metoden, som er utviklet i løpet av denne oppgaven. En sammenligning av SimPAC2-resultater med simuleringer basert på kun CFD og FEM, samt sjekket mot fysisk utførte målinger. En kjedeverifisering utføres, med utgangspunkt i en simulering av en enkel geometri av piezoelektriske elementer i luft uten strømning og i jevn strømning. Kompleksiteten økes med simuleringen av en diametral en-stråle mengdemåler utstyrt med enten piezo-elektriske elementer eller ekte transdusere. Til slutt ble en industriell mengdemåler med to kordale strålebaner simulert og verifisert i en kalibreringsrigg. Resultatene stemte overens innen fastsatte kriterier. Simuleringene gjorde det mulig å systematisk studere og kvantifisere komplekse, forventede effekter i UTTF, for eksempel 3D-hulromseffekter for flush monterte, tilbaketrekkende eller utstikkende transdusere. De utførte 3D-multifysikksimuleringene fanger opp interaksjoner mellom ultralydbølger og strømning i 3D-geometrien som per definisjon ikke kan fanges opp av 2D-simuleringer. Før SimPAC2 var det dyrt eller umulig å utføre systematiske 3D-multifysikksimuleringer. Dermed oppnås simulering av en full 3D-geometri av en UTTF fra inngangsspenning på senderen til utgangsspenning på mottakeren. Det er demonstrert at SimPAC2 kan brukes videre som et verktøy for design og optimalisering av UTTF, reduksjon av utviklingssyklusen og forbedring av nøyaktighet og linearitet.Ultrasonic Transit-Time Flowmeters (UTTF) and their modeling are on the main focus in this dissertation. UTTF can be categorized into clamp-on and inline devices depending on the needs of applications for flow measurement. Simulations, studies, and experimental verification of inline gas devices with high demands of accuracy are performed in the present work. It is demonstrated that with the use of simulations, it is conceivable to accelerate innovation, as well as to continuously improve measurement accuracy and technology for the fast-growing market of UTTF. In the present thesis, a multiphysics, hybrid numerical method is proposed i.e., a combination of a Finite Element Method (FEM) and a Finite Volume Method (FVM), for the purpose of 3D simulations and investigation of physical phenomena that affect the behavior of UTTF. The developed method, ’Simulations of Piezoelectricity, Acoustics, Coupled with CFD’ (SimPAC2), is used as a design tool of UTTF, as well as for the improvement of understanding the operation of UTTF. For the simulation, the UTTF is split into parts and the respective, more appropriate method is used for each part. More specifically, FEM is utilized for the simulation of piezoelectricity and structural acoustics in the solid parts i.e., the transducers and, if desired, partially the meter-body of the flowmeter. FEM is also used for the simulation of wave propagation in a part of the moving fluid medium. Acoustics and computational fluid dynamics (CFD) are considered in the moving fluid medium, as well as their interaction with each other with the use of FVM, which is traditionally more appropriate for CFD and large simulations that need to be highly parallelized. The hybrid SimPAC2 method requires complex interfaces between the FEM and FVM method, which are created in the course of the present work. A comparison of SimPAC2 results with pure CFD, FEM and measurements is carried out. A chain verification takes place, starting from a simulation of a simple geometry of piezoelectric elements in air in zero and uniform flow. Complexity is added with the simulation of a diametrical single-path flowmeter equipped with either piezoelectric elements or real transducers. Finally, a real industrial flowmeter with two chordal paths is simulated and measured in a flow rig, with the agreement of the results satisfying the set criteria. The simulations allowed for the systematic study and quantification of complex, much-anticipated effects in UTTF, such as 3D cavity effects, the position of flush, recessed, and protruded transducers, as well as the flow effect around the transducers and in the meter-body. The performed 3D multiphysics simulations capture interactions between ultrasonic waves and flow in the 3D geometry that are, by definition, not possible to be captured by 2D simulations. Before SimPAC2, the performance of systematic 3D multiphysics simulations was computationally expensive or impossible to perform. Thus, the simulation of a full 3D geometry of an UTTF is achieved from input voltage on the transmitter to output voltage on the receiver. It is demonstrated that SimPAC2 can be further used as a tool for the design and optimization of UTTF, the reduction of the development cycle and the improvement of accuracy and linearity.Doktorgradsavhandlin

Αναπαραστάσεις της γυναίκας και της οικογένειας στο λογοτεχνικό έργο της Γαλάτειας Καζαντζάκη

Το έργο της Γαλάτειας Καζαντζάκη και ειδικότερα οι αναπαραστάσεις της γυναίκας και της οικογένειας σε αυτό, αποτελούν αντικείμενο μελέτης της παρούσας εργασίας. Μια σημαντική παράμετρος που λαμβάνεται υπόψη είναι ότι η επεξεργασία των ζητημάτων αυτών που αποτελούσαν φλέγοντα ζητήματα του καιρού της, πραγματοποιείται από τη συγγραφέα, σε αρκετές περιπτώσεις, με τη χρήση μοτίβων από τον λαϊκό πολιτισμό και ειδικότερα από τα είδη της λαϊκής λογοτεχνίας. Η θεματική αυτή και μορφολογική ποικιλία επιχειρείται να μελετηθεί μέσα από τη θεωρητική σύγκλιση των πεδίων της Λαογραφίας και της Φιλολογίας. Διαπιστώνεται ότι η Γαλάτεια Καζαντζάκη, όπως και άλλοι συγγραφείς του καιρού της, αξιοποιεί τον λαϊκό πολιτισμό και ειδικότερα τις μορφές και τα είδη της λαϊκής λογοτεχνίας, όπως το παραμύθι και το δημοτικό τραγούδι, για να αναπτύξει τις προσωπικές της ιδέες της για τη γυναίκα και την οικογένεια. Στο έργο της Γ. Καζαντζάκη υπάρχουν πολλές αναφορές σε διάφορες γιορτές και έθιμα, όψεις της αγροτικής ζωής κ.α., καθώς η συγγραφέας έθεσε σε πολλά δημιουργήματά της ως χώρο δράσης την ελληνική ύπαιθρο, άλλοτε για να εξάρει πτυχές της κι άλλοτε για να καταδικάσει τους υποκριτικούς κώδικες ηθικής. Το έργο της διακρίνεται από αγάπη για τον λαϊκό άνθρωπο, για τον αγρότη ή τον εργάτη. Η Γαλάτεια Καζαντζάκη, επιχείρησε επίσης, αντλώντας από τα είδη της λαϊκής λογοτεχνίας, να περάσει τις απόψεις της για τη θέση της γυναίκας, για την πραγματικά αξιοπρεπή κι έντιμη αντισυμβατική και κατ’ επέκτασιν χειραφετημένη γυναίκα, τροποποιώντας τα δεδομένα και τις κατεστημένες απόψεις για τη συγκρότηση της οικογένειας στην εποχή της.The work of Galatia Kazantzakis and in particular the representations of woman and family in it form object of study in this present thesis. An important parameter to be taken into account is that the elaboration of these issues, which were burning issues of her time, is carried out by the author, in several cases, with the use of motifs from the popular culture and especially from the genres of popular literature. This thematical and morphological variety is attempted to be studied through the theoretical convergence of the fields of Folklore and Philology. It is proven that Galatia Kazantzakis, as other writes of her time, utilizes the popular culture and especially the forms and genres of the folk literature, such as the fairy tale and the folk song, to develop her personal ideas about women and family. In G. Kazantzakis’s work there are many references about various celebrations and customs, aspects of the rural life etc. as the writer set the Greek countryside as a place of action in many of her creations, sometimes to exalt aspects of herself and sometimes to condemn the hypocritical codes of ethics. Her work is distinguished by love for the common man, for the farmer or the worker. Galatia Kazantzakis also tried, drawing on the genres of popular literature, to pass on her views on the position of women, on the truly dignified and honest unconventional and consequently emancipated woman, by modifying the data and the established views on the composition of the family in her time

Emotional Intelligence and Caring Behaviors of Mental Health Nurses in Greece

The purpose of this descriptive study of correlation of the synchronic type is to investigate the level of Emotional Intelligence (EQ) and Caring Behaviors exhibited by nurses in mental health, as well as the relationship with their individual characteristics

Leiomyosarcoma of the Penis

We report a case of a 78-year-old patient with penile leiomyosarcoma, treated by radical penectomy. Two years after the operation the patient is without evidence of local recurrence or metastatic disease.We also discuss the treatment options and attempt a review of the literature

Impact of the c-MybE308G mutation on mouse myelopoiesis and dendritic cell development

Booreana mice carrying the c-Myb308G point mutation were analyzed to determine changes in early hematopoiesis in the bone marrow and among mature cells in the periphery. This point mutation led to increased numbers of early hematopoietic stem and progenitor cells (HSPCs), with a subsequent reduction in the development of B cells, erythroid cells, and neutrophils, and increased numbers of myeloid cells and granulocytes. Myelopoiesis was further investigated by way of particular subsets affected. A specific question addressed whether booreana mice contained increased numbers of dendritic-like cells (L-DC subset) recently identified in the spleen, since L-DCs arise in vitro by direct differentiation from HSPCs co-cultured over splenic stroma. The non-lethal c-Myb mutation in booreana mice was associated with significantly lower representation of splenic CD8- conventional dendritic cells (cDCs), inflammatory monocytes, and neutrophils compared to wild-type mice. This result confirmed the bone marrow origin of progenitors for these subsets since c-Myb is essential for their development. Production of L-DCs and resident monocytes was not affected by the c-MybE308G mutation. These subsets may derive from different progenitors than those in bone marrow, and are potentially established in the spleen during embryogenesis. An alternative explanation may be needed for why there was no change in CD8+ cDCs in booreana spleen since these cells are known to derive from common dendritic progenitors in bone marrow.This work was supported by a project grant #585443 to HO from the National Health and Medical Research Council (NHMRC) of Australia. PP was supported by an NHMRC CJ Martin Fellowship. YH was supported by a postgraduate scholarship from the Australian National Universit

Sarcopenia in patients with diabetes mellitus.

IntroductionDiseases such as diabetes mellitus may be associated with adverse changes in body composition. Sarcopenia is characterized by a progressive and generalized loss of skeletal muscle mass and functionality.AimTo investigate the relationship between type 2 diabetes mellitus (T2DM) and sarcopenia.Materials and methodsIn a retrospective, non-randomized study, 35 T2DM patients, aged 20-80 years, were assessed for sarcopenia prevalence compared to controls (n=16). Appendicular skeletal mass (ASM) (kg) was measured, and sarcopenia was defined as SMI ResultsIncidence of sarcopenia was significantly higher in T2DM patients vs. controls (27% vs. 20%, p=0.01) and elderly vs. young participants (40% vs. 12%, pConclusionsA moderate prevalence of sarcopenia in patients with type 2 diabetes mellitus was observed, which appeared to increase significantly in older men. Finally, incidence of T2DM displayed decreased physical performance in both genders

Multi-center study of inter-rater reproducibility, image quality, and diagnostic accuracy of CZT versus conventional SPECT myocardial perfusion imaging

Cadmium-zinc-telluride (CZT)-based detectors exhibit higher diagnostic sensitivity in myocardial perfusion imaging (MPI) than conventional Anger-MPI for detection of coronary artery disease (CAD); however, reduced specificity and diagnostic accuracy of CZT-MPI were observed. This study aims to compare these different camera systems and to examine the degree of inter-rater reproducibility among readers with varying experience in MPI. 83 patients who underwent double stress/rest examinations using both a CZT and conventional SPECT cameras within one visit were included. Anonymized and randomized MPI-images were distributed to 15 international readers using a standardized questionnaire. Subsequent coronary angiography findings of ten patients served as a reference for analysis of sensitivity and specificity. Image quality was significantly better in CZT-MPI with significantly lower breast attenuation (P < 0.05). CZT-MPI exhibited higher sensitivity than Anger-MPI (87.5% vs. 62.5%) and significantly reduced specificity (40% vs. 100%). Readers experienced with both camera systems had the highest inter-rater agreement indicating higher reproducibility (CZT 0.54 vs. conv. 0.49, P < 0.05). Higher diagnostic sensitivity of CZT-MPI offers advantages in detection of CAD yet potentially of at the cost of reduced specificity, therefore it requires special training and a differentiated evaluation approach, especially for non-experienced readers with such camera systems. The online version contains supplementary material available at 10.1007/s12350-022-03054-w