Thesis (B.S.)--University of Missouri, School of Mines and Metallurgy, 1935. / The entire thesis text is included in file. Typescript. Title from title screen of thesis/dissertation PDF file (viewed June 9, 2010) Includes bibliographical references (p. [29]).

Thesis (B.S.)--University of Missouri, School of Mines and Metallurgy, 1937. / The entire thesis text is included in file. Typescript. Title from title screen of thesis/dissertation PDF file (viewed May 6, 2010) Includes bibliographical references (p. 22-23) and index (p.25).

A percentage of insulating glass (IG) units break each year due to thermally induced perimeter stresses. The glass industry has known about this problem for many years and an ASTM standard has recently been developed for the design of monolithic glass plates for thermal stresses induced by solar irradiance. It is believed that a similar standard can be developed for IG units if a proper understanding of IG thermal stresses can be developed. The objective of this research is to improve understandings of IG thermal stresses and compare the IG thermal stresses with those that develop in monolithic glass plates given similar environmental conditions. The major difference between the analysis of a monolithic glass plate and an IG unit is energy exchange due to conduction, natural convection, and long wave radiation through the gas space cavity. In IG units, conduction, natural convection, and long wave radiation combine in a nonlinear fashion that frequently requires iterative numerical analyses for determining thermal stresses in certain situations. To simplify the gas space energy exchange, a numerical propagation procedure was developed. The numerical propagation procedure combines the nonlinear effects of conduction, natural convection, and long wave radiation into a single value. Use of this single value closely approximates the nonlinear nature of the gas space energy exchange and simplifies the numerical analysis. The numerical propagation procedure was then coupled with finite element analysis to estimate thermal stresses for both monolithic glass plates and IG units. It is shown that the maximum thermal stresses that develop in IG units increase linearly with input solar irradiance during the transient phase. It is shown that an initial preload stress develops under equilibrium conditions due to the thermal bridge effects of the spacer. It is shown that IG units develop larger thermal stresses than monolithic glass plates under similar environmental conditions. Finally, it is shown that the use of low-e coatings increase IG thermal stresses and that the location of low-e coating as well as environmental conditions affect which glass plate develops larger thermal stresses.

No description available.

Thesis (M.S.)--University of Michigan, 1969.

Thesis (Ph. D.)--Mississippi State University. Department of Electrical and Computer Engineering. / Title from title screen. Includes bibliographical references.

Thesis (M.S.)--University of Michigan, 1969.

Thesis (B.S.)--University of Missouri, School of Mines and Metallurgy, 1939. / The entire thesis text is included in file. Typescript. Title from title screen of thesis/dissertation PDF file (viewed April 26, 2010) Includes bibliographical references (p. 25).

Ως δίκτυο υψηλής τάσης εναλλασσόμενου ρεύματος ορίζουμε το δίκτυο που λειτουργεί υπό τάση από 1kV και πάνω. Όπως γνωρίζουμε, στους εξοπλισμούς υψηλής τάσης η μόνωση είναι απαραίτητο συστατικόγια την προστασία αυτών και τη σωστή λειτουργία τους, η δε χρήση μονωτικών λαδιών έχει καθιερωθεί εδώ και δεκαετίες,για να καλύψει την παραπάνω ανάγκη. Στη διπλωματική αυτή εργασία θα εκτελέσουμε μια σειρά πειραμάτων,για να δοκιμάσουμε τη διηλεκτρική αντοχή ενός συγκεκριμένου εξευγενισμένου ναφθενικό ορυκτέλαιο του Shell Diala Oil σε καταπόνηση εντός διακένου με γραμμικά αυξανόμενη AC τάση, μεταβάλλοντας το εύρος του διακένου, τον τύπο των ηλεκτροδίων και παίρνοντας μετρήσεις με ανάδευση ή όχι του δείγματος μετά από κάποιες ημέρες ηρεμίας αυτού. Για τη διεξαγωγή των δοκιμών μας χρησιμοποιήθηκε η συσκευή BAUR Oil Tester DTA 822-129-1 και πάρθηκαν τα απαραίτητα μέτρα, για να εξασφαλιστεί η αξιοπιστία των πειραματικών αποτελεσμάτων που λάβαμε. Στα κεφάλαια 1, 2 και 3 παρατίθενται θεωρητικά στοιχεία που αφορούν τηχρήση, την προέλευση και τις βασικές ιδιότητες των μονωτικών λαδιών. Στο κεφάλαιο 4 παρουσιάζονται θεωρίες για τους μηχανισμούς διάσπασης των μονωτικών λαδιών. Στο κεφάλαιο 5 βρίσκεται το πειραματικό μέρος της διπλωματικής,όπου παρουσιάζονται η διαδικασία διεξαγωγής του πειράματος, τα χρησιμοποιηθέντα όργανα, οι κανόνες ασφαλείας που ακολουθήσαμε και τέλος τα πειραματικά αποτελέσματα και η διασύνδεση αυτών με τηθεωρητική μας βάση. / --

Increasing demand for high-density memories has necessitated the search for new materials with higher dielectric constants to satisfy the minimum charge storage density requirements. Several materials such as Ta₂O₅, BST¹, BBT² are being investigated to replace the currently used Si based oxide/nitride dielectrics. Among the materials under investigation, Ta₂O₅ is one of the most promising, especially from the fab compatibility point of view. Ta₂O₅ thin films offer a six-fold increase in dielectric constant compared to conventional dielectrics. However, the significant improvement in dielectric constant is offset by higher leakage currents compared to conventional dielectrics. Improvement in both, dielectric and insulating properties is required for the successful integration of Ta₂O₅ thin films into devices. In the current research work, it was demonstrated that by chemically modifying the tantalum pentoxide matrix, significant improvements in its electrical properties can be achieved which would enable the fabrication of a reliable high-density memory device. In the present work, the effects of Al addition on Ta₂O₅ thin films were systematically studied. The structural and electrical properties of these chemically modified thin films were investigated in detail to establish their potential for device applications. The effects on dielectric and insulating characteristics due to incorporation of Al in Ta₂O₅ matrix were studied in capacitor configuration. A metallorganic solution decomposition (MOSD) technique was used to deposit thin films onto Pt coated Si(100) substrates. The capacitors were fabricated by sputter depositing Pt electrodes on the top surface of the films. The dielectric and insulating properties of pure and modified Ta₂O₅ thin films and their dependence on film composition, processing temperature, and the thickness were discussed and an attempt was made to provide theoretical understanding for the experimental observations. The dielectric and insulating properties of Ta₂O₅ were found to be significantly modified by addition of Al. It was observed that Al addition has decreased the leakage currents approximately by an order of magnitude and improved thermal and bias stability characteristics of Ta₂O₅ capacitors. For example, the leakage currents in crystalline pure Ta₂O₅ thin films were found to be 4.5 x 10⁷ A/cm² in a 1MV/cm dc field which decreased to 3.4 x 10⁸ A/cm² for 10% Al modified Ta₂O₅ thin films. A typical dielectric constant of 42.5 was obtained for 10% Al modified Ta₂O₅ thin films. This is significantly higher compared to the commonly reported dielectric constant of 25 to 35 for Ta₂O₅ thin films. This enhancement was attributed to strong (100) orientation exhibited by both pure and modified Ta₂O₅ thin films. The high dielectric constant, low dielectric loss, low leakage currents and low temperature coefficient of capacitance suggest the suitability of Al modified Ta₂O₅ as a capacitor dielectric for future generation DRAM applications. ¹Barium strontium titanate, ²Barium bismuth tantalate / Master of Science