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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Geology and ore genesis of the Sam Goosly copper-silver-antimony deposit, British Columbia

Wetherell, Dennis Gene January 1979 (has links)
Geology, opaque mineralogy, and alteration assemblages of the Sam Goosly copper-silver-antimony deposit are described in detail and a model for ore genesis is proposed. The deposit occurs in an inlier of Cretaceous sedimentary, pyro-clastic, and volcanic rocks. This inlier is intruded by a quartz monzonite stock in the western part of the property and by a gabbro-monzonite complex in the eastern half. Flat lying to shallow dipping Tertiary andesitic to basaltic flows uncomfortably overlie Cretaceous rocks around the flanks of the inlier. Based on careful examination of over 4,875 m of drill core and on limited surface mapping, four stratigraphic subdivisions striking about 015 degrees and dipping about 45 degrees west have been identified. The Clastic Division, composed of a lower polymictic conglomerate and an upper chert pebble conglomerate, is lowermost and is thought to be correlative with the Skeena Group. Sedimentary rocks are overlain by the Pyroclastic Division, a heterogeneous sequence of tuff, breccia, and reworked pyroclastic debris. Tuff, sandstone, and conglomerate of the Sedimentary-Volcanic Division have well defined bedding and overlie pyroclastic rocks. The uppermost unit composed of andesitic and dacitic flows, is the Volcanic Flow Division. Copper-silver-antimony ores at Sam Goosly are contained in the Main Zone and Southern Tail deposits and are associated with tourmaline, andalusite, scorzalite, and corundum (only in the Main Zone). They are epigenetic and cross-cutting relationships are visible both in hand specimen and throughout the deposit as a whole. The ores occur within the Pyroclastic Division and although they are controlled mainly by structure, crude strati graphic controls are also apparent. Other mineralized areas at Sam Goosly are a zone of porphyry copper-molybdenum mineralization in and adjacent to the quartz monzonite stock and a zone of tourmaline breccia. Similarities in mineralogy, textures, and paragenesis among all four mineralized areas suggest that they are genetically related. Potassium-argon dating of hydrothermal alteration indicates that mineralization occurred almost simultaneously with, the emplacement of the quartz monzonite stock. It is suggested here that copper-silver-antimony ores are related to the porphyry system and were deposited in a subvolcanic environment peripheral to porphyry mineralization. Early stages of mineralization took place between 400° C and 491° C; sulfides continued to form as the system cooled below 300° C. During subsequent thermal metamorphism of the Main Zone deposit adjacent to the gabbro-monzonite complex, pyrrhotite and sillimamite formed in an aureole about 90 m wide. Temperatures during metamorphism are thought to be above 750°C and pressures to be less than 350 bar (about 1 km depth). / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Unknown
12

Determinação da estrutura de uma série de tri(hidroximetil) amino metano complexados com íons metálicos (Cu, Ag, Ni, Zn) / X-ray crystal structures of Cu, Ag, Ni and Zn íons with tri(hidroximetil) amino methane

Silva, Lenilda Austrilino 05 December 1986 (has links)
As estruturas do tri(hidroximetil) amino metano complexado com cobre Cu(II), Cu[NH2C(COH3)3]2+H2O e do tri(hidroximetil)amino metano dopado com prata Ag(I), Ag[NH2C(COH3)3] foram determinados por difração de raios-x. O complexo contendo íons de cobre refinou até um R de 0.034 e foram encontradas as seguintes características principais: sistema cristalino monoclínico; grupo espacial C2/c, a=12.955(2)Å b=10.793(1)Å c=10.091(2)Å &#946=116.62° V=1261.3(6)޵ Z=4; xDc=1.694(2)g/cm-3; &#955(K&#945Mo)=0.71073Å das reflexões medidas 1441 tinham I&#62 3&#948 (I). O íon de cobre está coordenado por pares de átomos de oxigênio e nitrogênio os quais formam uma pirâmide de base quadrada, o oxigênio da molécula de água ocupa o outro vértice da pirâmide. A determinação dessa estrutura é utilizada na interpretação da formação de complexos de cobre com tri(hidroximetil) amino metano em função do pH. A estrutura do tri(hidroximetil) amino metano dopado com prata apresentou as seguintes características: sistema cristalino ortorrômbico; grupo espacial Pna21; a=7.800(2)Å b=8.810(3)Å c=8.850(2)Å V=608.85(4)޵ Dc=1.329g/cm-3; Dm=1.337g/cm-3; 435 reflexões com I&#62 3&#948 (I); R=0.13; o carbono central é coordenado tetraedricamente por três átomos de carbono do tri(hidroximetil) e um nitrogênio do grupo amino. As estruturas do tris dopado com níquel, e do tris dopado com zinco apresentam-se isomorfa com a estrutura do tris dopado com prata. / The crystal structures of the tri(hydroxymethyl) amine methane complexed with cooper Cu[NH2C(COH3)3]2+H2O and the silver Ag[NH2C(COH3)3] doped into the tri(hydroxymethyl) amine methane have been determined by x-ray diffraction. The complex involving Cu++ refined to final R-factor of 0.034, and the following main features were found: the crystal system is monoclinic and its space group is C2/c, a=12.955(2)Å b=10.793(1)Å c=10.091(2)Å &#946=116.62° V=1261.3(6)޵ Z=4; Dc=1.694(2)g/cm-3; &#955(K&#945Mo)=0.71073Å from measures done, 1441 had I&#62 3&#948 (I). The Cu++ is coordinated by couples of atoms of oxygen and nytrogen, which form a base of a quadrangular pyramid, the pyramid vertex is formed by the oxygen of the water molecule. The determination of this structure is used to interpret the rise of tri(hydroxymethyl) amine methane and complexed with Cooper varying the pH. The silver doped into the structures of tris(hydroxymethyl) amine methane presented the following features: crystal system is orthorrombic; space group is Pna21; a=7.800(2)Å b=8.810(3)Å c=8.850(2)Å V=608.85(4)޵ Dc=1.329 g/cm-3; Dm=1.337 g/cm-3; R=0.13; 435 reflections with I&#62 3&#948 (I) the central carbon is coordinated tetrahedrally by three atoms of carbon from tri(hydroxymethyl) and a nitrogen from the amine group.
13

Determinação da estrutura de uma série de tri(hidroximetil) amino metano complexados com íons metálicos (Cu, Ag, Ni, Zn) / X-ray crystal structures of Cu, Ag, Ni and Zn íons with tri(hidroximetil) amino methane

Lenilda Austrilino Silva 05 December 1986 (has links)
As estruturas do tri(hidroximetil) amino metano complexado com cobre Cu(II), Cu[NH2C(COH3)3]2+H2O e do tri(hidroximetil)amino metano dopado com prata Ag(I), Ag[NH2C(COH3)3] foram determinados por difração de raios-x. O complexo contendo íons de cobre refinou até um R de 0.034 e foram encontradas as seguintes características principais: sistema cristalino monoclínico; grupo espacial C2/c, a=12.955(2)Å b=10.793(1)Å c=10.091(2)Å &#946=116.62° V=1261.3(6)޵ Z=4; xDc=1.694(2)g/cm-3; &#955(K&#945Mo)=0.71073Å das reflexões medidas 1441 tinham I&#62 3&#948 (I). O íon de cobre está coordenado por pares de átomos de oxigênio e nitrogênio os quais formam uma pirâmide de base quadrada, o oxigênio da molécula de água ocupa o outro vértice da pirâmide. A determinação dessa estrutura é utilizada na interpretação da formação de complexos de cobre com tri(hidroximetil) amino metano em função do pH. A estrutura do tri(hidroximetil) amino metano dopado com prata apresentou as seguintes características: sistema cristalino ortorrômbico; grupo espacial Pna21; a=7.800(2)Å b=8.810(3)Å c=8.850(2)Å V=608.85(4)޵ Dc=1.329g/cm-3; Dm=1.337g/cm-3; 435 reflexões com I&#62 3&#948 (I); R=0.13; o carbono central é coordenado tetraedricamente por três átomos de carbono do tri(hidroximetil) e um nitrogênio do grupo amino. As estruturas do tris dopado com níquel, e do tris dopado com zinco apresentam-se isomorfa com a estrutura do tris dopado com prata. / The crystal structures of the tri(hydroxymethyl) amine methane complexed with cooper Cu[NH2C(COH3)3]2+H2O and the silver Ag[NH2C(COH3)3] doped into the tri(hydroxymethyl) amine methane have been determined by x-ray diffraction. The complex involving Cu++ refined to final R-factor of 0.034, and the following main features were found: the crystal system is monoclinic and its space group is C2/c, a=12.955(2)Å b=10.793(1)Å c=10.091(2)Å &#946=116.62° V=1261.3(6)޵ Z=4; Dc=1.694(2)g/cm-3; &#955(K&#945Mo)=0.71073Å from measures done, 1441 had I&#62 3&#948 (I). The Cu++ is coordinated by couples of atoms of oxygen and nytrogen, which form a base of a quadrangular pyramid, the pyramid vertex is formed by the oxygen of the water molecule. The determination of this structure is used to interpret the rise of tri(hydroxymethyl) amine methane and complexed with Cooper varying the pH. The silver doped into the structures of tris(hydroxymethyl) amine methane presented the following features: crystal system is orthorrombic; space group is Pna21; a=7.800(2)Å b=8.810(3)Å c=8.850(2)Å V=608.85(4)޵ Dc=1.329 g/cm-3; Dm=1.337 g/cm-3; R=0.13; 435 reflections with I&#62 3&#948 (I) the central carbon is coordinated tetrahedrally by three atoms of carbon from tri(hydroxymethyl) and a nitrogen from the amine group.
14

Functionalization of particles and selective functionalization of surfaces for the electroless metal plating process

Mondin, Giovanni 28 November 2014 (has links)
Electroless plating is a metal deposition technique widely used in the coating industry. It is the method of choice to plate substrates with complex geometries and nonconductive surfaces, such as polymers and ceramics, since it is based on a chemical reduction in solution rather than on an external electrical energy source like the electroplating method. Among others, examples of well-established applications are the electroless deposition of decorative metal coatings such as gold and silver, wear and corrosion resistant nickel coatings, particularly to coat drive shafts, rotors, and bathroom fixtures, as well as the electroless deposition of copper in electronic devices as diffusion barriers and conductive circuit elements. In the academic research, electroless plating is extensively used thanks to its low cost, simple equipment and versatility that allow rapid prototyping. Two common applications are the coating of small particles and the selective plating of flat surfaces. Metal coated ceramic particles are of enormous interest in many scientific fields, e.g. fluorescent diagnostics in biochemistry, catalysis, and fabrication of photonic crystals. Metal coated ceramic nanoparticles and microparticles are also gaining attention as potential candidates in the fabrication of higher quality metal matrix Composites, which is one of the applications addressed by this work. Metal coated ceramic particles are easier to integrate in metal matrix composites, avoiding aggregation caused by the low wettability of the particles by the matrix metal, and are potentially shielded from oxidation and undesired chemical reactions that take place at the interface between the particles and the metal Matrix. Electroless plating is an autocatalytic process, meaning that the deposited metal atoms catalyze the deposition of further metal. In order to achieve the first stable metal seeds on a surface, the latter has to be functionalized. Without this functionalization the metal ions in the electroless plating bath are not reduced or are simply reduced to metal nanoparticles in solution. The traditional activation step for nonconductive surfaces is performed by immersion of the substrate in palladium based solutions, which is very time-consuming and extremely expensive. In particular for nanoparticles, previous work showed that at least 1015 Pd atoms/cm2 are required for a uniform activation of a surface, meaning that in the case of nanoparticles with a surface area of about 100 m2/g are necessary 6.4 g of palladium for each gram of substrate. Assuming a price of about 150 €/g (laboratory scale) for palladium nanoparticles and palladium precursors used for surface activation, it results that the activation of 1 g of nanoparticles costs around 1000 €. Such costs are suboptimal considering the typical production scale, and therefore alternative functionalization methods are desired. In this work, new organic-based functionalization methods based on (3-mercaptopropyl)triethoxysilane to functionalize oxide particles, 3-aminopropylphosphonic acid to activate carbide particles and a substrate-independent method based on the bioinspired polydopamine are developed and investigated in detail, together with the respective electroless plating baths, which often have to be specifically tailored regarding the different reactivity of the different molecules and substrates. Furthermore, in the fabrication of metallic patterns on substrates by electroless plating, new, simple, and cost-effective activation and metal deposition processes are desired. In this work, two new methods are presented, one based on the printing of (3-mercaptopropyl)triethoxysilane by microcontact printing, the other based on the capillary force lithography of polymethylmethacrylate.
15

Tribology of Metal-Graphite Composites : A Study of Sliding Electrical Contact Surfaces

Grandin, Martina January 2017 (has links)
An environmentally sustainable production of electrical power is important for preserving the earth’s natural resources. In order to utilize this power as efficiently as possible, it is of great importance to minimize the losses, for example in sliding electrical contacts. A sliding electrical contact is where current is transferred from one rotating to one stationary component and power is lost due to friction and contact resistance. Also in some signal applications, high performance sliding contacts are crucial to ensure stable signal transfer with low noise. Although sliding electrical contacts are primarily designed for good electrical performance, the system will benefit also from optimization of the tribological properties. The aim of this thesis is to increase the fundamental knowledge of the tribological and electrical performance of metal-graphite composite materials for sliding electrical contacts. The influence of mechanical and electrical load was investigated. Different stationary materials, from pure copper to nanocomposite coatings, were tested against copper- and silver-graphites. Two complementary test setups were used, one with reciprocating and one with unidirectional sliding. Surface analysis was essential to gain deepened understanding of the influence of the interaction on the surfaces. Especially my novel imaging of cross-sections has advanced the level on knowledge in this research field. On the stationary material surface, a tribofilm forms with constituents from the metal-graphite and the surrounding atmosphere. Cross-sectioning reveals a material flow that indicates turbulence. Furthermore, the presence of oxides in the tribofilm is not necessarily detrimental for the contact resistance as long as there is also pure metal available. The presence of graphite is vital for low friction and wear. It is shown that the tribological and electrical behaviour of this system is only marginally influenced by the material selection of the stationary contact. Increasing the metal content in the composite, on the other hand, greatly reduces the contact resistance while there is no significant impact on friction and wear. The mechanical load has to be optimized to compromise between low wear (achieved with low load) and low contact resistance (achieved with high load). Pure mechanical tests show a lower friction and higher wear rate in comparison to tests with a five ampere current.
16

Cu(Ag)-Legierungsschichten als Werkstoff für Leiterbahnen höchstintegrierter Schaltkreise / Herstellung, Gefüge, thermomechanische Eigenschaften, Elektromigrationsresistenz

Strehle, Steffen 04 April 2007 (has links) (PDF)
Die vorliegende Arbeit verfolgt das Ziel, Cu(Ag)-Dünnschichten als potentiellen Werkstoff für Leiterbahnen in der Mikroelektronik zu untersuchen. Für die Beurteilung dieses Materialsystems wurden vier Schwerpunkte bezüglich der Schichtcharakterisierung definiert: Herstellung, Gefüge, thermomechanische Eigenschaften, Elektromigrationsresistenz. Grundlage sämtlicher Untersuchungen ist eine geeignete Probenpräparation. In Anlehnung an Technologien, die zur Zeit bei der Herstellung von reinen Cu-Leiterbahnen Anwendung finden, erfolgte die Beschichtung der Cu(Ag)-Schichten (Dicke bis 1 µm) galvanisch aus einem schwefelsauren Elektrolyten unter Additiveinsatz auf thermisch oxidierten Siliziumwafern. Hierbei war nicht nur die Abscheidung von ganzflächigen Dünnschichten, sondern auch die Beschichtung auf strukturierte Substrate von Interesse. Die erzeugten Schichtproben werden in ihren Gefügeeigenschaften, vergleichend zu reinen Kupferschichten, charakterisiert. Hierzu zählen Korngrößen und -orientierungen, thermisches Gefügeverhalten, Einbau, Verteilung und Segregation von Silber und Fremdstoffen sowie die elektrischen Eigenschaften. Von grundsätzlicher Bedeutung für das Elektromigrationsverhalten und damit für die Zuverlässigkeit und das Leistungsvermögen sind die thermomechanischen Eigenschaften. Diese werden an ausgedehnten Schichten mit der Substratkrümmungsmessung bis zu Temperaturen von 500°C beschrieben. Die Diskussion des mechanischen Schichtverhaltens umfasst sowohl thermische als auch temporale Charakteristika. Die Untersuchungen geben einen Einblick in die wirkenden Mechanismen des Stofftransports und des Spannungsabbaus. Den Abschluss der Arbeit stellen erste Experimente zum Elektromigrationsverhalten der Cu(Ag)-Dünnschichten dar. Den Kern dieser Analysen bilden Messungen an sog. Blech-Strukturen (Materialdriftexperimente). Hierbei werden geeignete Technologien für die mikrotechnologische Herstellung von derartigen Cu(Ag)-Strukturen vorgestellt. Anhand erster Messungen wird das Elektromigrationsverhalten von Cu(Ag)-Metallisierungen in seinen Grundcharakteristika beschrieben.
17

Cu(Ag)-Legierungsschichten als Werkstoff für Leiterbahnen höchstintegrierter Schaltkreise: Herstellung, Gefüge, thermomechanische Eigenschaften, Elektromigrationsresistenz

Strehle, Steffen 12 March 2007 (has links)
Die vorliegende Arbeit verfolgt das Ziel, Cu(Ag)-Dünnschichten als potentiellen Werkstoff für Leiterbahnen in der Mikroelektronik zu untersuchen. Für die Beurteilung dieses Materialsystems wurden vier Schwerpunkte bezüglich der Schichtcharakterisierung definiert: Herstellung, Gefüge, thermomechanische Eigenschaften, Elektromigrationsresistenz. Grundlage sämtlicher Untersuchungen ist eine geeignete Probenpräparation. In Anlehnung an Technologien, die zur Zeit bei der Herstellung von reinen Cu-Leiterbahnen Anwendung finden, erfolgte die Beschichtung der Cu(Ag)-Schichten (Dicke bis 1 µm) galvanisch aus einem schwefelsauren Elektrolyten unter Additiveinsatz auf thermisch oxidierten Siliziumwafern. Hierbei war nicht nur die Abscheidung von ganzflächigen Dünnschichten, sondern auch die Beschichtung auf strukturierte Substrate von Interesse. Die erzeugten Schichtproben werden in ihren Gefügeeigenschaften, vergleichend zu reinen Kupferschichten, charakterisiert. Hierzu zählen Korngrößen und -orientierungen, thermisches Gefügeverhalten, Einbau, Verteilung und Segregation von Silber und Fremdstoffen sowie die elektrischen Eigenschaften. Von grundsätzlicher Bedeutung für das Elektromigrationsverhalten und damit für die Zuverlässigkeit und das Leistungsvermögen sind die thermomechanischen Eigenschaften. Diese werden an ausgedehnten Schichten mit der Substratkrümmungsmessung bis zu Temperaturen von 500°C beschrieben. Die Diskussion des mechanischen Schichtverhaltens umfasst sowohl thermische als auch temporale Charakteristika. Die Untersuchungen geben einen Einblick in die wirkenden Mechanismen des Stofftransports und des Spannungsabbaus. Den Abschluss der Arbeit stellen erste Experimente zum Elektromigrationsverhalten der Cu(Ag)-Dünnschichten dar. Den Kern dieser Analysen bilden Messungen an sog. Blech-Strukturen (Materialdriftexperimente). Hierbei werden geeignete Technologien für die mikrotechnologische Herstellung von derartigen Cu(Ag)-Strukturen vorgestellt. Anhand erster Messungen wird das Elektromigrationsverhalten von Cu(Ag)-Metallisierungen in seinen Grundcharakteristika beschrieben.

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