Parameters of Heine and Abarenkov model potential (HAP) have been computed in this paper for sixteen body centered cubic (bcc) closed pack crystals. From the minimization of structure dependent energy of the pure crystal the inter-relation between the two parameters is first determined. Calculation uses pseudopotential technique with nine different exchange and correlation functions (ECF) and either only available experimental value of vacancy formation energy (VFE) or that obtained from an empirical relation based on other experimental parameters (Melting temperature, cohesive energy or activation energy) as tool. The variation of VFE with one parameter of HAP and different ECF show sharp fall in VFE near very small value of it after which it shows constancy for all bcc crystals. Comparison is made with parameter of Ashcroft model also. For increase in valency this parameter of HAP increases and show distinct different curves.

It is expected that nano-scale devices and interconnections will introduce unprecedented level of defects in the substrates, and architectural designs need to accommodate the uncertainty inherent at such scales. This consideration motivates the search for new architectural paradigms based on redundancy based defect-tolerant designs. However, redundancy is not always a solution to the reliability problem, and often too much or too little redundancy may cause degradation in reliability. The key challenge is in determining the granularity at which defect tolerance is designed, and the level of redundancy to achieve a specific level of reliability. Analytical probabilistic models to evaluate such reliability-redundancy trade-offs are error prone and cumbersome, and do not scalewell for complex networks of gates. In this thesiswe develop different tools and techniques that can evaluate the reliability measures of combinational circuits, and can be used to analyze reliability-redundancy trade-offs for different defect-tolerant architectural configurations. In particular, we have developed two tools, one of which is based on probabilistic model checking and is named NANOPRISM, and another MATLAB based tool called NANOLAB. We also illustrate the effectiveness of our reliability analysis tools by pointing out certain anomalies which are counter-intuitive but can be easily discovered by these tools, thereby providing better insight into defecttolerant design decisions. We believe that these tools will help furthering research and pedagogical interests in this area, expedite the reliability analysis process and enhance the accuracy of establishing reliability-redundancy trade-off points. / Master of Science

In this thesis we conclude that convolutional neural networks, together with phase-measuring deflectometry techniques, can be used to create models which can detect and classify defects on painted surfaces very well, even compared to experienced humans. Further, we show which preprocessing measures enhances the performance of the models. We see that standardisation does increase the classification accuracy of the models. We demonstrate that cleaning the data through relabelling and removing faulty images improves classification accuracy and especially the models' ability to distinguish between different types of defects. We show that oversampling might be a feasible method to improve accuracy through increasing and balancing the data set by augmenting existing observations. Lastly, we find that combining many images with different patterns heavily increases the classification accuracy of the models. Our proposed approach is demonstrated to work well in a real-time factory environment. An automated quality control of the painted surfaces of Volvo Truck cabins could give great benefits in cost and quality. The automated quality control could provide data for a root-cause analysis and a quick and efficient alarm system. This could significantly streamline production and at the same time reduce costs and errors in production. Corrections and optimisation of the processes could be made in earlier stages in time and with higher precision than today. / I den här rapporten visar vi att modeller av typen convolutional neural networks, tillsammans med phase-measuring deflektometri, kan hitta och klassificera defekter på målade ytor med hög precision, även jämfört med erfarna operatörer. Vidare visar vi vilka databehandlingsåtgärder som ökar modellernas prestanda. Vi ser att standardisering ökar modellernas klassificeringsförmåga. Vi visar att städning av data genom ommärkning och borttagning av felaktiga bilder förbättrar klassificeringsförmågan och särskilt modellernas förmåga att särskilja mellan olika typer av defekter. Vi visar att översampling kan vara en metod för att förbättra precisionen genom att öka och balansera datamängden genom att förändra och duplicera befintliga observationer. Slutligen finner vi att kombinera flera bilder med olika mönster ökar modellernas klassificeringsförmåga väsentligt. Vårt föreslagna tillvägagångssätt har visat sig fungera bra i realtid inom en produktionsmiljö. En automatiserad kvalitetskontroll av de målade ytorna på Volvos lastbilshytter kan ge stora fördelar med avseende på kostnad och kvalitet. Den automatiska kvalitetskontrollen kan ge data för en rotorsaksanalys och ett snabbt och effektivt alarmsystem. Detta kan väsentligt effektivisera produktionen och samtidigt minska kostnader och fel i produktionen. Korrigeringar och optimering av processerna kan göras i tidigare skeden och med högre precision än idag.

This study has been designed to discover how the development of an integrating personality is influenced by defective speech; to ascertain whether or not personal growth is promoted by the correction of said defects, and to discover therapeutic measures if such are warranted.

No / Review article. No abstract.

Metal-based additive manufacturing (AM) has emerged as a cutting-edge technology for fabricating complex geometries with high precision. However, the major challenges to the wider adoption of metal AM technologies are process uncertainty-induced quality issues. Consequently, there is an urgent need for fast and reliable certification techniques for AM components, which can be achieved by leveraging Artificial Intelligence (AI)-enabled modeling. Developing a robust AI-enabled model presents a significant challenge because of the costly and time-intensive nature of acquiring diverse and high volume of datasets. In this context, the data-sharing attributes of Manufacturing-as-a-Service (MaaS) platforms can facilitate the development of AI-enabled certification techniques in a collaborative manner. However, sharing process data poses critical concerns about protecting users’ intellectual property and privacy since it contains confidential product design information. To address these challenges, the overarching goal of this research is to investigate how process data and process physics can be leveraged to develop in-situ component certification techniques focusing on data privacy for metal AM systems. This dissertation aims to address the need for novel quality monitoring methodologies by utilizing diverse data sources derived from a range of printed samples. Specifically, the research effort focuses on 1) the use of in-situ thermal history data and ex-situ X-ray computed tomography data for real-time layer-wise anomaly detection method development by analyzing the morphological dynamics of melt pool images; 2) the development of a framework to evaluate the design information disclosure of various thermal history-based feature extraction methods for anomaly detection; and 3) the privacy-preserving and utility-aware adaptive AM data deidentification method development that takes thermal history data as input.

L’excellente coulabilité, les coûts de production relativement bas, et ratio poids/résistance mécanique élevé des alliages de fonderie Al-Si-Mg en font une des solutions les plus intéressantes dans le secteur automobile ainsi que dans le domaine aérospatial. Toutefois, il est bien connu que la durée de vie de ces composants moulés à grand nombre de cycles (105 < Nf < 107 cycles) est sévèrement réduite lorsque des défauts de fonderie (notamment pores et oxydes) sont débouchants et/ou subsurfaciques sont présents. Ces défauts concentrent les contraintes et peuvent considérablement réduire la période d’amorçage des fissures de fatigue en fonction de leur taille, forme et des caractéristiques microstructurales du matériau. Les défauts internes (à partir desquels les fissures peuvent amorcer et propager sans interaction avec l’air ambiant) ainsi que les défauts de surface (ceux qui sont placés à la surface et en contact direct avec l’air ambiant) vont également nuire la durée de vie des composants moulés. Toutefois, dans le cas des défauts internes, les coefficients de sécurité préconisés par les règles de conception ne font pas intervenir la distance de défaut par rapport à la surface. Le suivi de fissures de fatigue effectué à la surface d’éprouvettes macroscopiques de traction indique que la présence d’un défaut avec une taille supérieure à celle des fissures microstructuralement courtes (√A ≈ 500 μm, taille contrôlée par la SDAS) produit une remarquable réduction de la durée vie. En revanche, la durée de vie n’est pas affectée lorsqu’un défaut plus petit (√A ≈ 300 μm) est présent à la surface car l’amorçage et les premiers stades de propagation sont encore influencés par la SDAS. Les essais de fatigue en torsion pure montrent que la morphologie des surfaces de rupture est fortement influencée par le niveau de contrainte. De plus, le nombre de cycles à l’amorçage est réduit par rapport à la traction. Cet amorçage est multi-site et plusieurs fissures peuvent croitre simultanément au cours de la durée de vie d’une éprouvette, la rupture finale se produisant lors de la jonction de certaines de ces fissures. La propagation des fissures en torsion est largement influencée par la cristallographie locale et les retassures ne semblent pas être des sites de nucléation préférentiels. Les durées de vie odes échantillons macroscopiques contenant défauts artificiel internes (Øeq ≈ 2 mm) sont pratiquement similaires à celles obtenues avec un matériau de référence. L’amorçage et la propagation de fissures internes a été rarement observé lors des expériences de tomographie synchrotron. Dans les rares cas où de telles fissures ont pu être observées, le chemin de fissuration semble fortement influencé par la cristallographie alors que les fissures amorcées depuis la surface se propagent globalement en mode I. La vitesse de propagation des fissures internes est très inférieure à celle des fissures se propageant à partir de la surface. / The excellent castability, relatively low production costs, and high strength to weight ratios make Al-Si-Mg cast alloys an attractive choice for use in cheaper and lighter engineering components, in both automotive and aerospace industries. However, it is well known that High Cycle Fatigue (HCF) lives (105 < Nf < 107 cycles) of cast components are severely reduced when casting defects (notably pores and oxides) are present at the free surface or subsurface. They act as stress raisers which can considerably reduce the crack incubation period depending on their size, shape and the microstructural features of the surrounding material. Internal casting defects are of special interest to this work. The application of safety coefficients considers that all casting defects present in a component have the same deleterious effect and no attention is paid, for example, to their distance to the free surface. In other words, internal defects (corresponding to the case where the depth of the defect allows crack nucleation and propagation to essentially occur without interaction with the air environment) are considered as damaging to fatigue life as surface defects (those placed at the free surface and in contact with the air environment). Surface crack monitoring performed on uniaxial fatigue specimens indicates that the presence of a surface microshrinkage exceeding the size of microstructurally small cracks (√A ≈ 500 μm, controlled by the SDAS) readily nucleates a fatigue cracks producing steady crack propagation and remarkable reduction in the expected fatigue life. A smaller surface defect (√A ≈ 300 μm) nucleated a crack that did not reduced the expected fatigue life as in this case early stages of propagation are still nfluenced by the SDAS. Pure torsional cycling reveals that the morphology of fracture surfaces is highly influenced by the stress level. In general, torsional fatigue behaviour is described by having reduced (with respect to uniaxial testing) and multisite crack nucleation periods. Several dominant cracks can evolve simultaneously and the final failure occurs by the linkage of some of those cracks. Crack propagation is controlled by the crystallography and pores do not appear to be preferential nucleation sites. S-N curves show that macroscopic specimens containing Øeq ≈ 2 mm internal artificial defect produce similar fatigue lives to those obtained with a defect-free material. Internal crack nucleation was rarely observed during synchrotron tomography experiments; instead the fatal cracks initiated from much smaller surface defects. Tomographic images show that, in the case of internal propagation, crystallographic paths are formed while surface cracks propagate in mode I. The crack growth rate of internal cracks is much smaller than that of cracks propagating from the free surface.

Master of Science / Department of Chemical Engineering / J. H. Edgar / Boron phosphide, BP, is a III-V compound semiconductor with a wide band gap of 2.0 eV that is potentially useful in solid state neutron detectors because of the large thermal neutron capture cross-section of the boron-10 isotope (3840 barns). In this study, cubic BP crystals were grown by crystallizing dissolved boron and phosphorus from a nickel solvent in a sealed (previously evacuated) quartz tube. The boron - nickel solution was located at one end of the tube and held at 1150°C. Phosphorus, initially at the opposite end of the tube at a temperature of 430°C, vaporized, filling the tube to a pressure of 1–5 atmospheres. The phosphorus then dissolved into solution, producing BP. Transparent red crystals up to 4 mm in the largest dimension with mostly hexagonal shape were obtained with a cooling rate of 3°C per hour. The crystal size decreased as the cooling rate increased, and also as growth time decreased. The characterization with x-ray diffraction (XRD) and Raman spectroscopy established that the BP produced through this method were highly crystalline. The lattice constant of the crystals was 4.534 Ǻ, as measured by x-ray diffraction. Intense, sharp Raman phonon peaks were located at 800 cm[superscript]-1 and 830 cm[superscript]-1, in agreement with the values reported in the literature. The FWHM for XRD and Raman spectra were 0.275° and 4 cm[superscript]-1 which are the narrowest ever reported and demonstrates the high quality of the produced crystals. Energy dispersive x-ray spectroscopy (EDS) and scanning electron microscope (SEM) also confirmed the synthesized crystals were cubic BP crystals, with a boron to phosphorus atomic ratio of 1:1. Defect selective etching of BP at 300ºC for two minutes with molten KOH/NaOH revealed triangular and striated etch pits with low densities of defects of ~4 x 10[superscript]7 cm[superscript]-2 and 9.2 x 10[superscript]7 cm[superscript]-2 respectively. The BP crystals were n-type, and an electron mobility of ~39.8 cm[superscript]2/V*s was measured. This is favorable for application in neutron detection. Scaling to larger sizes is the next step through gradient freezing and employing a larger crucible.

BACKGROUND:Cancers often arise within an area of cells (e.g. an epithelial patch) that is predisposed to the development of cancer, i.e. a "field of cancerization" or "field defect." Sporadic colon cancer is characterized by an elevated mutation rate and genomic instability. If a field defect were deficient in DNA repair, DNA damages would tend to escape repair and give rise to carcinogenic mutations.PURPOSE:To determine whether reduced expression of DNA repair proteins Pms2, Ercc1 and Xpf (pairing partner of Ercc1) are early steps in progression to colon cancer.RESULTS:Tissue biopsies were taken during colonoscopies of 77 patients at 4 different risk levels for colon cancer, including 19 patients who had never had colonic neoplasia (who served as controls). In addition, 158 tissue samples were taken from tissues near or within colon cancers removed by resection and 16 tissue samples were taken near tubulovillous adenomas (TVAs) removed by resection. 568 triplicate tissue sections (a total of 1,704 tissue sections) from these tissue samples were evaluated by immunohistochemistry for 4 DNA repair proteins. Substantially reduced protein expression of Pms2, Ercc1 and Xpf occurred in field defects of up to 10 cm longitudinally distant from colon cancers or TVAs and within colon cancers. Expression of another DNA repair protein, Ku86, was infrequently reduced in these areas. When Pms2, Ercc1 or Xpf were reduced in protein expression, then either one or both of the other two proteins most often had reduced protein expression as well. The mean inner colon circumferences, from 32 resections, of the ascending, transverse and descending/sigmoid areas were measured as 6.6 cm, 5.8 cm and 6.3 cm, respectively. When combined with other measurements in the literature, this indicates the approximate mean number of colonic crypts in humans is 10 million.CONCLUSIONS:The substantial deficiencies in protein expression of DNA repair proteins Pms2, Ercc1 and Xpf in about 1 million crypts near cancers and TVAs suggests that the tumors arose in field defects that were deficient in DNA repair and that deficiencies in Pms2, Ercc1 and Xpf are early steps, often occurring together, in progression to colon cancer.

Korrektur der Fallotschen Tetralogie nach vorhergehender Palliativoperation - Langzeitergebnisse aus einem historischen Patientenkollektiv Hintergrund: Die Fallotschen Tetralogie ist ein komplexer zyanotischer Herzfehler, der erst mit dem Einsatz der Herz-Lungen-Maschine korrigiert werden kann. Zuvor erfolgte eine palliativ Operation. Seit 1960 werden Patienten mit Fallotscher Tetralogie in der Klinik für Thorax, -Herz- und Gefäßchirurgie der Universität Göttingen operiert. Ziel der Arbeit ist es, die Langzeitergebnisse eines historischen Patientenkollektivs, die zwischen 1960 und 1984 zuerst mit einer palliativen Operation behandelt und im Anschluss die Korrektur-Operation erhalten haben, zu analysieren. Methoden: Von 1960 bis 1984 erhielten 324 Patienten mit Fallotscher Tetralogie eine Korrektur-Operation nachdem zuvor eine Palliativ-Operation durchgeführt wurde. Die Datenanalyse erfolgte retrospektiv. Drei Gruppen wurden anhand der primären Palliativ-Operation gebildet: BTA-Gruppe (Blalock-Taussig-Anastomose, n=250), WCA-Gruppe (Waterstone-Cooley-Anastomose, n=57) und AD-Gruppe (verschiedene andere palliative Verfahren, n=17). Ergebnisse: Das mittlere Patientenalter war zur Korrektur-Operation in der BTA-Gruppe signifikant höher (8,45 ± 4,62 Jahre vs. 6,89 ± 2,96 Jahre in der WCA-Gruppe; p=0,0015). Die Operationsdauer war in der BTA-Gruppe mit 283 ± 105 Minuten kürzer im Vergleich zur WCA-Gruppe 314 ± 114 Minuten (p=0,32 ???). Intraoperativ wurde unter anderem eine Erweiterungsplastik mit Patch bei 64,5% durchgeführt (BTA: 63,2%, WCA: 70,2%), von diesen waren 48,8% transannulär (BTA: 44,3%, WCA: 75%). Postoperativ war eine Rethorakotomie nach der Korrektur-Operation in der WCA-Gruppe seltener (11% vs. 25% in der BTA-Gruppe; p=0,002). Die Korrektur-Operation führte in allen Gruppen zu einer effektiven, signifikanten Reduktion des rechtsventrikulären Druckes (BTA: von 96,01 ± 21,17 mmHg auf 52,75 ± 15,79 mmHg, WCA: von 97,78 ± 34,73 mmHg auf 59,05 ± 15,04 mmHg; p <0,001). Die Dauer der mechanischen Ventilation nach der Korrektur-Operation war in der BTA-Gruppe signifikant kürzer als in der WCA-Gruppe (46 ± 57 Stunden vs. 108 ± 207 Stunden; p=0,002), ebenso dauerte der Intensivaufenthalt in der BTA-Gruppe signifikant kürzer (117 ± 100 Stunden vs. 189 ± 205 Stunden in der WCA-Gruppe; p<0,001). Die Frühletalität betrug im Gesamtkollektiv 15,1%, Unterschiede zwischen den Gruppen???. Im weiteren Verlauf starben 12 weitere Patienten, so dass die Gesamtletalität 18,8% beträgt. Beim letzten Kontakt befanden sich die meisten Patienten im NYHA-Stadium II und III (NYHA-Stadium des Gesamtkollektivs: 2,3 ± 1,0; BTA-Gruppe: 2,2 ± 1,0; WCA-Gruppe: 2,7 ± 0,8). Schlussfolgerung: Die Datenanalyse zeigt, dass von den Palliativ-Operationen vor einer Korrektur-Operation bei Fallotscher Tetralogie, die BTA die vorteilhaftere Variante darstellt. Bei der Korrektur-Operation hatten die Patienten nach vorheriger BTA-Shunt-Operation eine kürzere OP-Dauer, weniger Blutungen postoperativ, sowie kürzere Beatmungs- und Intensivaufenthaltsdauer. Nach Korrektur der Fallotschen Tetralogie zeigen alle Patienten eine effiziente Verbesserung der hämodynamischen Parameter und ein gutes klinisches Langzeitergebnis. Da das optimale Operationsverfahren von mehreren Faktoren abhängt (u.a. Alter des Patienten, klinischen Zustand und anatomische Gegebenheiten), muss eine individuelle Entscheidung erfolgen und falls eine Palliativ-Operation notwendig ist, sollte die Anlage einer BTA bevorzugt werden.