abstract: Dimensional Metrology is the branch of science that determines length, angular, and geometric relationships within manufactured parts and compares them with required tolerances. The measurements can be made using either manual methods or sampled coordinate metrology (Coordinate measuring machines). Manual measurement methods have been in practice for a long time and are well accepted in the industry, but are slow for the present day manufacturing. On the other hand CMMs are relatively fast, but these methods are not well established yet. The major problem that needs to be addressed is the type of feature fitting algorithm used for evaluating tolerances. In a CMM the use of different feature fitting algorithms on a feature gives different values, and there is no standard that describes the type of feature fitting algorithm to be used for a specific tolerance. Our research is focused on identifying the feature fitting algorithm that is best used for each type of tolerance. Each algorithm is identified as the one to best represent the interpretation of geometric control as defined by the ASME Y14.5 standard and on the manual methods used for the measurement of a specific tolerance type. Using these algorithms normative procedures for CMMs are proposed for verifying tolerances. The proposed normative procedures are implemented as software. Then the procedures are verified by comparing the results from software with that of manual measurements. To aid this research a library of feature fitting algorithms is developed in parallel. The library consists of least squares, Chebyshev and one sided fits applied on the features of line, plane, circle and cylinder. The proposed normative procedures are useful for evaluating tolerances in CMMs. The results evaluated will be in accordance to the standard. The ambiguity in choosing the algorithms is prevented. The software developed can be used in quality control for inspection purposes. / Dissertation/Thesis / Masters Thesis Mechanical Engineering 2014

abstract: There is very little in the way of prescriptive procedures to guide designers in tolerance specification. This shortcoming motivated the group at Design Automation Lab to automate tolerancing of mechanical assemblies. GD&T data generated by the Auto-Tolerancing software is semantically represented using a neutral Constraint Tolerance Feature (CTF) graph file format that is consistent with the ASME Y14.5 standard and the ISO STEP Part 21 file. The primary objective of this research is to communicate GD&T information from the CTF file to a neutral machine readable format. The latest STEP AP 242 (ISO 10303-242) “Managed model based 3D engineering“ aims to support smart manufacturing by capturing semantic Product Manufacturing Information (PMI) within the 3D model and also helping with long-term archiving of the product information. In line with the recommended practices published by CAx Implementor Forum, this research discusses the implementation of CTF to AP 242 translator. The input geometry available in STEP AP 203 format is pre-processed using STEP-NC DLL and 3D InterOp. While the former is initially used to attach persistent IDs to the topological entities in STEP, the latter retains the IDs during translation to ACIS entities for consumption by other modules in the Auto-tolerancing module. The associativity of GD&T available in CTF file to the input geometry is through persistent IDs. C++ libraries used for the translation to STEP AP 242 is provided by StepTools Inc through the STEP-NC DLL. Finally, the output STEP file is tested using available AP 242 readers and shows full conformance with the STEP standard. Using the output AP 242 file, semantic GDT data can now be automatically consumed by downstream applications such as Computer Aided Process Planning (CAPP), Computer Aided Inspection (CAI), Computer Aided Tolerance Systems (CATS) and Coordinate Measuring Machines (CMM). / Dissertation/Thesis / Masters Thesis Mechanical Engineering 2016

abstract: This thesis contains the applications of the ASU mathematical model (Tolerance Maps, T-Maps) to the construction of T-Maps for patterns of line profiles. Previously, Tolerance Maps were developed for patterns of features such as holes, pins, slots and tabs to control their position. The T-Maps that are developed in this thesis are fully compatible with the ASME Y14.5 Standard. A pattern of square profiles, both linear and 2D, is used throughout this thesis to illustrate the idea of constructing the T-Maps for line profiles. The Standard defines two ways of tolerancing a pattern of profiles - Composite Tolerancing and Multiple Single Segment Tolerancing. Further, in the composite tolerancing scheme, there are two different ways to control the entire pattern - repeating a single datum or two datums in the secondary datum reference frame. T-Maps are constructed for all the different specifications. The Standard also describes a way to control the coplanarity of discontinuous surfaces using a profile tolerance and T-Maps have been developed. Since verification of manufactured parts relative to the tolerance specifications is crucial, a least squares fit approach, which was developed earlier for line profiles, has been extended to patterns of line profiles. For a pattern, two tolerances are specified, and the manufactured profile needs to lie within the tolerance zones established by both of these tolerances. An i-Map representation of the manufactured variation, located within the T-Map is also presented in this thesis. / Dissertation/Thesis / M.S. Mechanical Engineering 2014

Abstract The purpose of the current study was to evaluate the intercorrelations of magnetic resonance imaging (MRI) findings and clinical symptoms and signs in sciatic patients. Furthermore, determinants of spontaneous HNP resorption and the effect of anti-inflammatory treatments (periradicular methylprednisolone injection and intravenous infliximab) on spontaneous HNP resorption were evaluated. MRI follow-up was performed at baseline, after two months, after six months and after one-year for patients with unilateral sciatica to evaluate determinants of spontaneous HNP resorption and the effect of periradicular methylprednisolone injection on spontaneous HNP resorption. At baseline the study population consisted of 160 patients (group A). MRI follow-up for 21 patients with unilateral sciatica was performed at baseline and after two weeks, after three months and after six months to evaluate the effect of infliximab, a monoclonal TNFα antagonist, infusion on spontaneous HNP resorption (group B). Patients in group A were randomized to receive either periradicular saline or methylprednisolone. Volume of HNP, extent and thickness of enhancement (in Gd-DTPA MRI) and degree of disc displacement were measured and the symptoms and signs were followed repeatedly. The extent of rim enhancement correlated significantly with the degree of disc displacement. The duration of sciatic symptoms correlated negatively with enhancement parameters. The clinical symptoms did not correlate significantly with the different enhancement parameters or disc herniation volume. Achilles reflex abnormality correlated significantly with all enhancement parameters for lesions at L5-S1. Significant decrease in HNP volume occurred from baseline to two moths, and even more so during the whole one year follow-up period. Higher baseline scores of rim enhancement thickness, higher degree of HNP displacement in the Komori classification and age category of 41–50 years were associated with a higher resorption rate. Clinical symptoms alleviation occurred concordantly with a faster resorption rate. No significant difference was noted in the decrease of HNP volume in the saline and methylprednisolone injection groups in follow-up imaging during one year. The enhancement parameters (thickness and extent of rim enhancement) did not differ significantly in the different treatment groups. In group B, 11 patients received intravenous infliximab and 10 saline. Baseline demographic data, pain scores, and clinical status, did not differ between the treatment groups. HNP volume decreased significantly in both groups (P < 0.01). There was no significant difference in HNP volume changes between the treatment groups. By two weeks, enhancement thickness increased significantly in the infliximab compared placebo group (p=0.003). Two patients in each group required back surgery prior to the 6-month assessment.

The field of crystallography has recently been expanded to include the science of quasicrystals, crystalline structures lacking unit cells and conventional periodicity. This resulted in a paradigm shift in the field, opening up for a whole new branch on the subject of structural chemistry. Despite this, not much is known about the abilities of quasicrystalline and approximant materials. Quasicrystalline approximants in the RE-Au-SM system have previously shown promising results regarding magnetic properties. To explore and discover properties like this is key to further improve the understanding of quasicrystalline materials.   The scope of the project was to explore the Gd-Au-Si system with compositions theoretically calculated to yield possible quasicrystals. In three batches with varying composition ratios, crystals were synthesised, using an arc-melting self-flux method. These were then analysed with powder X-ray diffraction, single crystal X-ray diffraction and electron dispersive spectroscopy (EDS) to characterise the synthesised compounds using diffraction data and composition data respectively. The resulting crystals were determined to be of a ternary composition close to what was theoretically calculated. The phase synthesised is yet to be found in any previous work or database, possibly marking it out as a new phase, albeit the structure not being quasicrystalline in nature. Thus, the exploratory study yielded a so for unobserved composition in the Gd-Au-Si system.

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第20083号 / 医博第4176号 / 新制||医||1018(附属図書館) / 33199 / 京都大学大学院医学研究科医学専攻 / (主査)教授 増永 慎一郎, 教授 妹尾 浩, 教授 松田 道行 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

Atomistic modelling has widely been applied for studying structures and properties of materials. There are various methods to perform atomistic modelling. This master thesis presents a combined density functional theory (DFT) and cluster expansion (CE) study of Gd2O3 and Gd2O3-CeO2 interface (GCI) relevant for solid oxide fuel cells (SOFCs).    The energy differences (ΔE) of Va-O exchanges in C-type Gd2O3 and at GCI are calculated using both DFT and CE methods. We also calculated the migration energy (Emig) of Va jumps in Gd2O3 and at GCI by DFT. The comparison between the CE and DFT results demonstrates that the CE method provides a relatively accurate estimation of ΔE while it requires less computational resources. Furthermore, the CE method is used to study the Va migration in the vicinity of the Gd2O3-CeO2 interface. The potential energy landscapes of different types of paths are studied. / Atomistisk modellering har i stor utsträckning använts för att studera strukturer och  egenskaper  hos  material.  Det  finns  många  olika  metoder  för  att  utföra atomistisk   modellering.   Detta   masterprojekt   presenterar   en   kombinerad density functional theory (DFT) och   cluster expansion (CE) studie av Gd2O3- och Gd2O3-CeO2 gränssnittet (GCI), relevant för fastoxidbränsleceller (SOFC). Energiskillnaderna (ΔE) för Va-O-utbytet i C-typ Gd2O3 och vid GCI beräknas med   användning   av   både   DFT-   och   CE-metoder.   Vi   beräknade   också migrationsenergin   (Emig)   av   Va-hopp   i   Gd2O3   och   vid   GCI   med   DFT. Jämförelsen  mellan  CE  och  DFT-resultaten  visar  att  CE-metoden  ger  en relativt    noggrann    uppskattning    av ΔE    samt    att    den    kräver    mindre beräkningsresurser.   Vidare   används   CE-metoden   för   att   studera   Va- migrering  i   närheten   av   Gd2O3-CeO2-gränssnittet.   Det   potentiella   energilandskapet  för olika vägar studeras.

<p>Ideally, the nominal design of a part or assembly, created with 3D Computer-Aided Design and Manufacturing (CAD/CAM) software, can be consistently fixtured and machined. In reality, process conditions vary, and feedback and correction methods such as integrated on-machine inspection, analysis, and process adjustment, are required.</p> <p>On-machine inspection based on touch trigger probes is well established, but limited motion control computing capability restricts analysis to simple arithmetic. This prevents on-line use of known whole part mathematical analysis software that implements the part salvaging intentions of modern Geometric Dimensioning and Tolerancing (GD&T) standards. Additionally, no CNC integrated method exists for geometrically adjusting nominal tool paths so that an in-tolerance final part is produced. Machine tool support for high data rate sensors such as laser scanners is also lacking.</p> <p>This thesis reports progress towards bidirectional integration of machine tool mounted inspection sensors with GD&T analysis software, and subsequent toolpath adjustment. The concepts are demonstrated using a fixture consisting of three datum spheres and a workpiece. The fixture is clamped in the CNC machine, datum spheres are measured, and after mathematical data fitting and registration, an in-tolerance final part is produced. To facilitate multiple tests, a tool path is split into four and machined in four poses with measurement and tool path adjustment for each pose. Preliminary integration of a laser scanner with axis scales and computer software was also accomplished.</p> / Master of Applied Science (MASc)

Die geometrische Produktspezifikation (GPS) ist für Unternehmen eine wesentliche Triebfeder um sich in Konstruktions- und Entwicklungsprozessen neu auszurichten. Mit der 3-dimensionalen Bemaßung an der CAD-Geometrie sollen alle Aspekte der Geometriebeschreibung datenneutral umgesetzt werden. Dazu gehören Toleranzdefinitionen die den Anspruch der Funktion, der Fertigbarkeit und der Messtechnik erfüllen. Die verfügbaren Werkzeuge zur normgerechten Toleranzdefinition am 3D-Teil haben sich in Creo 4 mit dem GD&T Advisor nochmals deutlich erweitert. Dies wird in diesem Vortrag mit dem Fokus auf die Toleranzanalyse in Creo 4 und der neuen CETOL Version 9 aufgezeigt.

The effect of individual additions of calcium oxide (CaO), Gd, Nd and Y was investigated on the microstructure, mechanical properties and corrosion resistance of the as-cast ZK40 alloy. The microstructural features were analised using optical, scanning and transmission electron microscopy, X-ray diffraction and Scanning Kelvin Atomic Probe Force Microscopy. The compressive and tensile behaviours of the as-cast alloys at room temperature were investigated. Electrochemical Impedance Spectroscopy, hydrogen evolution and weight loss under immersion in 0.5 wt.% NaCl solution were used to evaluate the corrosion behaviour. The results of the mechanical and corrosion tests were correlated with the microstructures. The 2 wt.% Gd addition enhanced the ductility, while the Nd addition resulted in deterioration in mechanical properties. The addition of 2 wt.% Gd and 1 wt.% Y resulted in the improvement of the ductility. The addition of CaO did not affect the mechanical properties while the 2 wt.% Nd deteriorate it. The 1 wt.% Y addition enhanced the ductility. The CaO addition did not caused enhancement in mechanical properties. The corrosion behaviour was enhanced with the addition of CaO and Gd. The modification of ZK40 with Gd opens up new perspectives in the development of Mg-Zn based alloys. / O efeito da adição individual de óxido de cálcio (CaO), Gd, Nd e Y foi investigado na microestrutura, propriedades mecânicas e resistência à corrosão de ligas ZK40 fundidas. As características microestruturais foram analisadas via microscopia óptica, microscopia eletrônica de varredura, microscopia eletrônica de transmissão, difração de Raios-X e \"Scanning Kelvin Atomic Probe Force Microscopy\". O comportamento à compressão e à tração das ligas à temperatura ambiente foi investigado. Espectroscopia eletroquímica de impedância, evolução de hidrogênio e ensaios de imersão em solução de 0.5% em peso de NaCl foram utilizados para avaliar a resistência à corrosão. Os resultados dos ensaios mecânicos e corrosão foram relacionados com a microestrutura. A adição de 2% em peso de Gd melhorou a ductilidade, ao passo que a adição de Nd resultou na piora das propriedades mecânicas. A adição de 2% em peso de Gd e 1% em peso de Y resultou na melhora da ductilidade. A adição de 1% em peso de Y causou uma melhora na ductilidade e a adição de CaO não teve impacto benéfico nas propriedades mecânicas. A resistência à corrosão foi melhorada com a adição de CaO e Gd. A modificação da liga ZK40 com a adição de Gd abre novas perspectivas no desenvolvimento de ligas Mg-Zn.