Dissertations / Theses: 'Copper in the body'

1

Fulcher, Yan G. "Functional studies of hCTR1, a high affinity human copper and cisplatin transporter." Diss., Columbia, Mo. : University of Missouri-Columbia, 2008. http://hdl.handle.net/10355/6048.

Full text

Abstract:

Thesis (Ph. D.)--University of Missouri-Columbia, 2008.
The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on June 19, 2009) Includes bibliographical references.

APA, Harvard, Vancouver, ISO, and other styles

2

Iskandar, Monica. "Elevated levels of dietary zinc intake modulate the expression of CCS and intestinal zinc trafficking proteins." Thesis, McGill University, 2005. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=84041.

Full text

Abstract:

Experiments were carried out to examine the value of CCS (copper chaperone for CuZn superoxide dismutase) as a novel biomarker of zinc-induced mild copper deficiency and to evaluate the changes in expression of zinc transporters in response to graded levels of moderately high dietary zinc. Weanling male Wistar rats were fed graded levels of zinc (30, 60, 120 and 240 mg zinc/kg diet) for 5 weeks. Results showed a dose-dependent decrease in copper content and an increase in CCS expression in tissues of rats fed the Zn-60 and Zn-120 diets. Surprisingly, rats fed the Zn-240 diet showed better copper status than rats fed the Zn-120 diet. Expression of zinc transporters was significantly upregulated in the small intestine of Zn-240 rats. Collectively, these data show that CCS is responsive to zinc-induced mild copper deficiency, and can serve as a sensitive biomarker of mild copper deficiency. The increased expression of intestinal zinc transporters expression may account for the better copper status of Zn-240 rats.

APA, Harvard, Vancouver, ISO, and other styles

3

Kinsman, George David. "The assessment of body copper status and its application to the study of atherosclerosis." Thesis, University of Cambridge, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239197.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Ke, Ying, and n/a. "Mechanisms by which COMMD1 down-regulates Epithelial Sodium Channel (ENaC) activity." University of Otago. Department of Physiology, 2008. http://adt.otago.ac.nz./public/adt-NZDU20081205.161914.

Full text

Abstract:

The epithelial sodium channel (ENaC) made up of α, β and γ subunits is located at the apical membrane of polarised epithelia and mediates transport of sodium ions into the cells. Tight control of ENaC function is essential for maintaining sodium homeostasis, blood volume and blood pressure. Controlling the number of active channels present at the cell surface appears to be critically important in regulating ENaC activity. The neural precursor cell expressed developmentally down-regulated gene 4 (Nedd4) family of proteins (eg. Nedd4-2) ubiquitinate ENaC and decrease its cell surface expression. The activity of Nedd4-2 is modulated by serum and glucocorticoid-induced kinase (SGK), which phosphorylates Nedd4-2 and increases cell surface expression of ENaC. The c̲o̲pper m̲etabolism gene M̲URR1 d̲omain 1 (COMMD1) protein is a recently identified ENaC binding partner and negative regulator of channel activity. Studies by other groups suggest that COMMD1 is also involved in the processes of intracellular protein trafficking and ubiquitin-dependent protein degradation. The aims of this study were 1). To characterise the interactions between COMMD1 and ENaC. 2). To identify the mechanism(s) by which COMMD1 down-regulates ENaC activity. Here protein-protein interaction studies were used to show that a recently identified conserved C-terminal domain (the COMM domain) in COMMD1 is essential for its binding to ENaC. The binding site for COMMD1 in βENaC was found to be located in its N-terminal domain. COMMD1 was shown to down-regulate ENaC by increasing ubiquitin modification of ENaC and by decreasing the cell surface population. COMMD1 was found to interact with SGK and formed a complex with SGK and Nedd4-2. Ussing chamber studies of Na⁺ transport showed that COMMD1 attenuated the stimulation of ENaC by SGK and abolished insulin-stimulated ENaC current in epithelial cells. Conversely, knock-down of COMMD1 increased ENaC current in mammalian epithelial cells. These data suggest that COMMD1 plays a role in regulating ENaC activity in epithelial cells and its effect is likely mediated via SGK. In addition COMMD1 was found to bind to the adaptor protein subunit [mu]2. Mutations in COMMD1 that disrupt its interaction with [mu]2 impair its ability to decrease cell surface expression of ENaC in Cos-7 cells, therefore COMMD1 may also have a role in the endocytosis of ENaC by linking cell surface ENaC to the clathrin-dependent endocytosis machinery. In summary, this study investigated the interactions between COMMD1 and ENaC and identified that the SGK/Nedd4-2 pathway is involved in the COMMD1-mediated ubiquitination and down-regulation of ENaC activity.

APA, Harvard, Vancouver, ISO, and other styles

5

Hoogeveen, Cornelis Adrianus Johannes Maria. "Hepatic apolipoprotein A-I synthesis andmRNA abundance, and whole body energy metabolism in copper-deficient rats." Diss., The University of Arizona, 1993. http://hdl.handle.net/10150/186449.

Full text

Abstract:

The influence of dietary copper deficiency on hepatic apolipoprotein A-I synthesis and mRNA abundance, as well as on whole body energy metabolism was examined in rats. Weanling male Sprague-Dawley rats were divided into two dietary treatments; copper-adequate (6.0 mg Cu/kg diet) and copper-deficient (0.6 mg Cu/kg diet). After 6 weeks of treatment, an increase in intravascular apolipoprotein A-I pool size was observed in copper-deficient rats. In part I, in vivo hepatic apolipoprotein A-I synthesis was determined by the injection of flooding dose of [³H]phenylalanine and measurement of the incorporation of [³H]phenylalanine into newly synthesized immunoprecipitable apolipoprotein A-I in liver homogenates as well as plasma. A pulse-chase study was designed using [³H]phenylalanine, to determine the in vitro hepatic apolipoprotein A-I synthesis and intracellular degradation in freshly isolated hepatocytes. Furthermore, hepatic apolipoprotein A-I mRNA abundance was determined by dot blot analysis. In part II, rats were individually housed in metabolic cages within indirect calorimetry units to study their energy metabolism. Total body composition was determined by total body electrical conductivity. Copper deficiency resulted in a specific 2-fold increase in hepatic apolipoprotein A-I synthesis and secretion. In vitro hepatic intracellular degradation was small and not affected by copper status. The hepatic apolipoprotein A-I mRNA abundance was increased by 28% when corrected for liver-to-body weight ratio in the copper-deficient rats. Copper deficiency resulted in a distinct shift in energy substrate utilization from carbohydrate to fat. Body weight gain and net energy retention were reduced as a result of copper deficiency. Total body composition analysis showed a reduction in percent fat mass in the copper-deficient rats. The present data suggest that copper deficiency results in an increased cellular demand for lipids as energy substrate in order to maintain an adequate energy balance. The observed increase in hepatic apo A-I synthesis may be a result of an increased demand for HDL formation to sustain an increased flux of lipid substrates between the liver and peripheral tissues, resulting in the observed hypercholesterolemia in copper-deficient rats.

APA, Harvard, Vancouver, ISO, and other styles

6

Tore, Micaela Ann. "Beyond Materiality: The Self and the Malleable Body in Alyse Knorr's Copper Mother and Dalton Day's Exit, Pursued." Bowling Green State University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1558455170150697.

Full text

APA, Harvard, Vancouver, ISO, and other styles

7

Zhang, Jin 1960. "The influence of copper deficiency on the binding and uptake of high-density lipoprotein by rat hepatic parenchymal cells." Thesis, The University of Arizona, 1988. http://hdl.handle.net/10150/276935.

Full text

Abstract:

This study was designed to examine the influence of Cu deficiency on the binding, uptake, and degradation of apolipoprotein E-free high density lipoproteins (apo E-free HDL) in cultured rat hepatic parenchymal cells. The binding of apo E-free HDL during time course studies was slightly but significantly increased in cells derived from Cu-deficient rats. In saturation studies, the amount of surface-bound apo E-free HDL appeared to be saturable, although no difference was observed between Cu-deficient and adequate animals. The amount of total and specific cell-associated uptake of apo E-free HDL was significantly increased in hepatic parenchymal cells of Cu-deficient animals. The present data suggest that hepatic uptake of the HDL protein moiety may be increased in rats fed a diet deficient in copper.

APA, Harvard, Vancouver, ISO, and other styles

8

Monasterios, Clevys Josefina. "Determination of copper and zinc at trace levels in human hair using a direct sample insertion technique for inductively coupled plasma atomic emission spectrometry." Thesis, McGill University, 1985. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=63251.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

Morgan, M. Thomas. "Molecular tools for elucidating copper biochemistry: Water-soluble fluorescent probes and robust affinity standards." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/51937.

Full text

Abstract:

Copper is an essential trace element for living organisms and has both known and additional suspected roles in human health and disease. The current understanding of copper metabolism is substantial but incomplete, particularly in regard to storage and exchange at the subcellular level, although available evidence indicates exchangeable intracellular copper is in the monovalent oxidation state. Selective fluorescent probes with sufficient sensitivity to detect Cu(I) availability at physiologically relevant levels and at subcellular resolution would be valuable tools for studying copper metabolism. As a contribution toward this goal, this work describes the development of Cu(I)-selective fluorescent probes with greatly improved aqueous solubility, contrast ratio, and fluorescence quantum yield. This work also describes the development of water-soluble, 1:1-binding chelators that form colorless, air-stable copper(I)-complexes. By acting as copper(I) buffering agents and affinity standards, these compounds can serve a complementary role to fluorescent probes in the study of copper biochemistry.

APA, Harvard, Vancouver, ISO, and other styles

10

Ashurian, Nicole. "Bodyscapes : body to body, body to city, body to self." Thesis, Massachusetts Institute of Technology, 2018. http://hdl.handle.net/1721.1/118683.

Full text

Abstract:

Thesis: M. Arch., Massachusetts Institute of Technology, Department of Architecture, 2018.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 106-107).
Our modern spaces are a result of a history of architects losing agency to technology. In the era of climate control spaces and the digital interfaces of social media, a sense of place and association with others is lost to enclosed spaces of satellite conversations detailed with attention to standardization rather than customization. These desires for comfort and control manifest in the lack of friction in our built realm. Spaces mirror the scaleless quality of the digital, impose no physical friction of environment and allow for isolation between bodies in the same room. Boarded in these spaces with the disappearing digital threshold, our friends fall in the same political silos as ourselves, empathy for others falters, context is arbitrary and we never have to be 'alone' when we have our phones. The tech industry tries to offer solutions to alleviate these problems with apps and devices. However, without a violent change in environment - engaging the physicality of the body, its senses and its association to others and site, the problems will persist. 'Bodyscapes' is a series of provocations at varying scales that subvert the language of corporate standardization to allow new opportunities for human interface where the public and private realm meet.
by Nicole Ashurian.
M. Arch.

APA, Harvard, Vancouver, ISO, and other styles

11

Clark, Susan Ferguson. "Copper status in multiple trauma patients : measurement of copper balance, serum copper and ceruloplasmin /." This resource online, 1990. http://scholar.lib.vt.edu/theses/available/etd-09162005-115033/.

Full text

APA, Harvard, Vancouver, ISO, and other styles

12

Graca, D. S. "Effects of copper depletion on subcellular hepatic copper and biliary copper excretion in cattle." Thesis, University of Aberdeen, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.370105.

Full text

APA, Harvard, Vancouver, ISO, and other styles

13

Clark, Susan F. "Copper status in multiple trauma patients: measurement of copper balance, serum copper and ceruloplasmin." Diss., Virginia Tech, 1990. http://hdl.handle.net/10919/39376.

Full text

Abstract:

see document
Changes in copper metabolism have been reported in both thermal injury and skeletal trauma; data regarding copper status in multiple trauma patients (MTP) are nonexistent. Hypercatabolism following multiple trauma may increase copper utilization, deplete copper stores and compromise cuproenzyme synthesis and function. The purpose of this study was to provide information on copper status in MTP and determine whether age, injury severity, clinical outcome or nutritional intake influenced copper status. Twenty-four hour copper losses, serum copper and ceruloplasmin were measured in 11 MTP with Injury Severity Scores (ISS) >12 at 24-48 hours post admission. Collections of biological fluids (urine, nasogastric, chest tube, drains, stools) were analyzed for copper using atomic absorption spectrophotometry (AAS) and quantified over 5 days. Serial serum copper and ceruloplasmin were determined on days 1,3,5,10,15 and patient discharge by ASS and rate nephelometry inmunoprecipition, respectively. Eight patients received parenteral nutrition (PN). Three received intravenous glucose/electrolyte infusions (IV). urine (n=11) and nasogastric losses (n=8) were statistically greater than normal (p<.001). The mean ± SEM cumulative copper losses of urine, chest tube drainage, nasogastric secretions and other drains were 790 ± 116 (n=11), 833 ± 130 (n=7), 261 ± 46 (n+8), and 150 ± 58 μg/5 d (n=8), respectively. Urinary losses represented 10 to 12 times the normal copper excretion. Serum copper on day 1 and ceruloplasmin day 3 were significantly higher than normal (p<.025). Cumulative copper balance in the IV group was - 2266 μg and -440 μg in the PN group. No relationship was found between copper loss and ISS. Patients in their twenties demonstrated the greatest urinary copper loss. The physiological and biochemical effects of extensive copper loss in the MTP require further evaluation. These patients may have a predisposition to copper deficiency due to excessive copper losses and may require increased copper supplementation.
Ph. D.

APA, Harvard, Vancouver, ISO, and other styles

14

Reed, Stewart T. "Copper adsorption/desorption characteristics on copper amended soils." Diss., This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-06062008-171512/.

Full text

APA, Harvard, Vancouver, ISO, and other styles

15

Mao, Zhong. "Effects of copper-ligand and copper-copper interactions on excited state properties of luminescent copper (I) complexes : structural and photophysical studies /." View the Table of Contents & Abstract, 2003. http://sunzi.lib.hku.hk/hkuto/record/B26450859.

Full text

APA, Harvard, Vancouver, ISO, and other styles

16

Mao, Zhong, and 毛中. "Effects of copper-ligand and copper-copper interactions on excited state properties of luminescent copper (I) complexes: structural and photophysical studies." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2003. http://hub.hku.hk/bib/B45015582.

Full text

APA, Harvard, Vancouver, ISO, and other styles

17

Gremillion, Eric J. "Copper Kingdom." ScholarWorks@UNO, 2015. http://scholarworks.uno.edu/td/1973.

Full text

Abstract:

This paper thoroughly examines the production of the thesis film Copper Kingdom. From writing, directing, production design, editing, to cinematography, sound, and workflow, each aspect of the creation of Copper Kingdom is carefully detailed, with insights regarding the decisions made throughout the filmmaking process.

APA, Harvard, Vancouver, ISO, and other styles

18

Törndahl, Tobias. "Atomic Layer Deposition of Copper, Copper(I) Oxide and Copper(I) Nitride on Oxide Substrates." Doctoral thesis, Uppsala University, Department of Materials Chemistry, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-4651.

Full text

Abstract:

Thin films play an important role in science and technology today. By combining different materials, properties for specific applications can be optimised. In this thesis growth of copper, copper(I) oxide and copper(I) nitride on two different substrates, amorphous SiO₂ and single crystalline α-Al₂O₃ by the so called Atomic Layer Deposition (ALD) techniques has been studied. This technique allows precise control of the growth process at monolayer level on solid substrates. Other characteristic features of ALD are that it produces films with excellent step coverage and good uniformity even as extremely thin films on complicated shaped substrates.

Alternative deposition schemes were developed for the materials of interest. It was demonstrated that use of intermediate water pulses affected the deposition pathways considerably. By adding water, the films are thought to grow via formation of an oxide over-layer instead of through a direct reaction between the precursors as in the case without water.

For growth of copper(I) nitride from Cu(hfac)₂ and ammonia no film growth occurred without adding water to the growth process. The Cu₃N films could be transformed into conducting copper films by post annealing. In copper growth from CuCl and H₂ the water affected film growth on the alumina substrates considerably more than on the fused silica substrates. The existence of surface -OH and/or -NH_x groups was often found to play an important role, according to both theoretical calculations and experimental results.

APA, Harvard, Vancouver, ISO, and other styles

19

Törndahl, Tobias. "Atomic layer deposition of copper, copper(I) oxide and copper(I) nitride on oxide substrates /." Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-4651.

Full text

APA, Harvard, Vancouver, ISO, and other styles

20

Fitzsimons, Nuala Patricia. "Copper hydride as a precursor for supported copper catalysts." Thesis, University of Cambridge, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.281998.

Full text

APA, Harvard, Vancouver, ISO, and other styles

21

Altass, Hatem. "HCl nanoscience at copper and copper/gold alloy surfaces." Thesis, Cardiff University, 2013. http://orca.cf.ac.uk/50823/.

Full text

Abstract:

The reaction of HCl with clean, Cu(100) and (111), and Au/ Cu(100) surfaces was investigated using x-ray photoelectron spectroscopy (XPS) and scanning tunneling microscopy (STM) under ultra high vacuum (UHV) conditions. Exposure of the Cu(100) and (111) samples to HCl at room temperature leads to the formation of a saturated copper chloride monolayer. In the case of Cu(100), the saturated coverage was half monolayer corresponding to a c(2x2)-Cl reconstruction (half monolayer is 7.25x1014 cm-2) while for Cu(111) it was one third monolayer consistent with the reconstruction of (√3x√3)R30o (one third monolayer 5.9x1014 cm-2). The interaction of HCl with preoxidised Cu(100) and (111) showed different behaviour from those of clean copper surface depending on the way of interaction of oxygen with copper surface. Interaction of HCl with peroxidised Cu(111) at saturation oxygen coverage leads to the adsorption of chlorine on top of the copper surface with one third coverage. In contrast, presence of oxygen on Cu(100) surface at saturation coverage or less leads to adsorb chlorine but with an excess in chlorine concentration (more than the expected c(2x2) coverage). Oxidized Cu(100) and (111) surface at elevated temperature leads to the formation multi oxide layer. The two oxide surfaces („‟44‟‟ and „‟29‟‟) observed at the Cu(111) depend on the temperature of the substrate at the time of oxidation. The (√2x2√2)R45o structure was observed on the Cu(100) surface on heating which is the same structure formed at saturation coverage at room temperature. Interaction of HCl with Cu(100) and (111) surfaces covered by multilayers of oxide lead to adsorption of chlorine on top of the copper surface with a coverage more than more than the saturation coverage. Interaction of HCl with Au/Cu(100) showed two different behaviour depending on the gold coverage. Au/Cu(100) alloy formed at half monolayer of gold coverage, forming c(2x2) structure. Exposure of the Au/Cu(100) alloy at half monolayer of gold coverage to HCl leads to the formation of c(2x2)-Cl structure with saturation coverage of half monolayer in similar manner of interaction of HCl with the clean cu(100) surface. Interaction of HCl with Au/Cu(100) surface at gold coverage more than half monolayer leads to a dealloying of the gold from the copper surface and forming the Au(111) surface. Cu-Cl formed underneath the Au(111) surface with excess of chlorine concentration.

APA, Harvard, Vancouver, ISO, and other styles

22

Kim, Eun-Hae. "Maintaining Copper Homeostasis - Molecular Studies on Bacterial Copper Transporters." Diss., The University of Arizona, 2011. http://hdl.handle.net/10150/205232.

Full text

Abstract:

Bacteria have evolved sophisticated cellular transport mechanisms to maintain metal homeostasis to not only utilize metals as important cofactors but also to evade the toxicity of these ions. The delicate balance is maintained by several homeostatic mechanisms that range from active cytoplasmic export, modification, sequestration, and periplasmic detoxification of toxic metals to the extracellular milieu. One mechanism involves active periplasmic extrusion of toxic substrates via a transmembrane spanning tripartite protein complex. The mechanism of substrate binding and subsequent efflux has yet to be elucidated. However, genetic, comparative genomic, biochemical, and functional analyses of the components of the heavy-metal efflux family have allowed the development of proposed models for a substrate transport pathway. The goals of this research were to identify the roles these systems play and to further characterize these systems on a molecular level to ultimately understand the mechanism of substrate transport. Elucidating a transport pathway in metal transporters allows for the development of a revised working model, which ultimately can have implications for antimicrobial drug development.

APA, Harvard, Vancouver, ISO, and other styles

23

Hyunjung, Cho. "The body of the embodied body." Thesis, Konstfack, Ädellab/Metallformgivning, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:konstfack:diva-3364.

Full text

Abstract:

By questioning the feeling of uneasiness coming from seeing the real body, I aim to cast a light upon the relation between the body and the objects that are displayed on it. Starting with a doubt that the object would not only change the surface of human, I investigate how the body of human totally embodies its representational object to itself.

APA, Harvard, Vancouver, ISO, and other styles

24

Schumer, Benjamin Nathan, and Benjamin Nathan Schumer. "Mineralogy of Copper Sulfides in Porphyry Copper and Related Deposits." Diss., The University of Arizona, 2017. http://hdl.handle.net/10150/626163.

Full text

Abstract:

Porphyry copper deposits represent one of the largest copper reserves on Earth. They typically contain large, low-grade reserves of primary ore and higher-grade, supergene enrichment blankets of sulfide and oxide ores. Understanding the mineralogy of porphyry copper ores and ores related to porphyry copper systems is exceedingly important for several reasons, foremost of which are the information provided by ore mineral parageneses, assemblages, and mineral chemistry on evolution of these magmatic-hydrothermal systems, and information on mineral processing characteristics of the ores. The focus of this work is to better understand the mineralogy of supergene copper sulfides in porphyry copper systems and hypogene base metal lodes related to porphyry copper systems, and use this mineralogical knowledge to improve our understanding of the processes responsible for ore formation. The objectives of this study are accomplished by two means: focusing on the crystallography and crystal chemistry of minerals, and then applying this mineralogical knowledge to a supergene sulfide enrichment blanket and hypogene massive sulfides from base metal lodes in southeastern Arizona. The discovery of a new mineral, natropalermoite, NaSr2Al4(PO4)4(OH)4, provided the opportunity to use single-crystal X-ray diffraction to solve a crystal structure, and electron-probe microanalysis (EPMA) to study the crystal chemistry of natropalermoite and how the accommodation of Na in the structure changes lengthens the unit cell along [010] and shortens it along [100] and [001] compared to its lithium analogue, palermoite. Solution of the crystal structure of the mineral nickelskutterudite, (Ni,Co,Fe)As3, allowed for the investigation of anion deficiency in minerals of the skutterudite group, a problem whose solution has eluded researchers for nearly 100 years. Two skutterudite (CoAs3) and two nickelskutterudite samples were analyzed using single-crystal X-ray diffraction, EPMA, and procrystal electron density. The results showed fully-occupied anion sites and a cation surplus, which was accommodated in the icosahedral site, proving that minerals of the skutterudite group are not anion deficient. This mineralogical knowledge was applied to the supergene enrichment blanket in the Western Copper section of the Morenci mine, Greenlee County, and hypogene massive sulfide deposits associated with a porphyry copper deposit at Bisbee, Cochise County, Arizona. This is one of very few studies of supergene sulfide blankets ever completed. One drill hole through the supergene blanket at Western Copper was examined using ore microscopy and EPMA. Results showed dominant (Cu+Fe):S ratios of 1.80 ± 0.05, 1.92 ± 0.03, and 1.10 ± 0.10, with higher (Cu+Fe):S dominant high in the blanket and low ratios dominant near the base of the blanket. These values were interpreted to be controlled by activity of Cu2+, Fe2+, and Fe3+ in solution. Massive sulfide deposits at Bisbee were investigated using ore microscopy and EPMA in order to correct the previous conflicting reports of the mineralogy and paragenesis of this famous district and interpret constraints on conditions of ore-forming fluids. Results show four types of ore: chalcopyrite-rich with hematite and/or pyrite, bornite-rich, chalcocite-rich, and a Zn-Pb association. Chalcopyrite-rich ores formed first, followed by bornite-rich and chalcocite-rich ores. All ores were formed at relatively shallow depths from oxidized, moderately sulfur-rich fluids; early fluids were higher temperature and later fluids were lower temperature and considerably more sulfidized. Zinc-lead ores formed early and were continuously dissolved and reprecipitated distal to Cu-mineralization. These patterns are similar to many other base-metal lode districts worldwide, however Bisbee contains more Zn-Pb ore than other districts with hematite-containing ores and less than those without hematite.

APA, Harvard, Vancouver, ISO, and other styles

25

Deng, Hua. "Electrochemical Deposition of Nanocrystalline Copper and Copper-Based Composite Films." NCSU, 2002. http://www.lib.ncsu.edu/theses/available/etd-20020103-173702.

Full text

Abstract:

Free-standing nanocrystalline copper-based composite and particle-free copper films were produced by direct- and pulse-current plating. Nanosize 50-nm Al2O3 or 5-nm diamond particles were codeposited into a copper matrix prepared on a rotating disk electrode (RDE). The electrolytes contained CuSO4.5H2O (0.25 M), H2SO4 (0.56 M or 1.5 M), 50-nm Al2O3 (12.5 g/L or 1.0 g/L) or 5-nm diamond (0.5 g/L) particles, and gelatine (0.1 g/L, 0.05 g/L, or 0.02 g/L). The deposition was carried out at room temperature. The RDE was rotated at 1800 rpm for high-alumina particle baths (12.5 g/L) and 1000 rpm for low-alumina particle (1.0 g/L), diamond particle (0.5 g/L), and particle-free baths. The free-standing composite and copper films were characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), micro hardness tester, and transmission electron microscopy (TEM). Grain size and crystal texture were obtained by XRD measurement. SEM gave information on surface morphology and composition of films. The hardness of nanocrystalline materials was measured by micro hardness tester. TEM was used to confirm the presence of nanocrystalline copper grains. The uncompensated potential became more cathodic with increasing current density in pulse-current plating. The current efficiency was in the range of 0.93 ¨C 1.09 for both direct- and pulse-current plating. Gelatine concentration, the presence of nanosize dispersoids, and pH have no significant effect on electrode potential and current efficiency. Grain size decreased with increasing current density for particle-free copper and most of the composite films by direct- and pulse-current plating. The microhardness of nanocrystalline materials was increased by decreasing grain size for most of the particle-free copper and composite films. The existence of high-angle grain boundaries in nanocrystalline films resulted in negative Hall-Petch slopes. The presence of low concentration of alumina or diamond particles had no effect on grain size and microhardness. The pH had no obvious influence on grain size, microhardness, and alumina content in composite films. Random crystal texture is observed for Cu-Al2O3 composite and particle-free copper films and the (111) preferred texture for Cu-diamond composite films. The (100) preferred substrate orientation had no effect on deposit texture. The current density for both direct- and pulse-current plating had no significant effect on material texture. The presence of particles has no significant influence on nanocrystalline texture. Surface morphology varied for films made under different bath conditions. High gelatine concentration resulted in low-particle impregnation. Films made using 0.1 g/L gelatine resulted in spherical particles with grain size of 64 nm and porous surface. Films made using 0.02 g/L gelatine resulted in smooth surface with smaller grains of 40 nm. Films with high-alumina particle embedding, for example sample 7/9-1, resulted in porous and dark surface. High-alumina particle concentration (12.5 g/L) with 0.02 g/L gelatine in the deposition baths resulted in high-alumina content (0.11 wt% - 2.76 wt%) in composite films. The higher current density (297 mA/cm2) resulted in the lower alumina particle (0.076 wt%) embedding rate for the same bath parameter setting. The presence of both Al and O was found in copper-alumina composites and C element (diamond) was detected in copper-diamond composite films by EDS.

APA, Harvard, Vancouver, ISO, and other styles

26

Middleton, Ruth Linda. "Alkyne coupling on copper and copper/palladium single crystal surfaces." Thesis, University of Cambridge, 1998. https://www.repository.cam.ac.uk/handle/1810/272595.

Full text

APA, Harvard, Vancouver, ISO, and other styles

27

Westlake, Michael Angelo 1966. "The oxidation of copper and silver plated copper lead frames." Thesis, The University of Arizona, 1993. http://hdl.handle.net/10150/278279.

Full text

Abstract:

The effects of thin silver films (15-210 angstroms) on the oxidation of copper alloy lead frames has been characterized. Silver films were deposited onto copper lead frames by immersion plating in a bath containing potassium silver cyanide, potassium cyanide, and a mercaptan inhibitor. The thickness of films was measured by microfocus x-ray fluorescence and cross-checked by Rutherford backscattering spectrometry. Lead frames coated with silver films were oxidized at 150 to 200°C in a controlled humidity oven. The amount of oxide formed was measured by an electrolytic reduction technique and cross-checked with weight gain measurements. Auger, ESCA, and SEM analysis were also performed on the films. A tape test was performed to obtain qualitative information on the adhesion of the films.

APA, Harvard, Vancouver, ISO, and other styles

28

Beatty, Kirk Matthew 1962. "Processing of copper aluminosilicate glasses to produce glass-copper structures." Thesis, The University of Arizona, 1993. http://hdl.handle.net/10150/278284.

Full text

Abstract:

Copper aluminosilicate (composition Cu₂O·Al₂O₃·6SiO₂) glass was melted in an alumina crucible at 1500°C and air cooled in situ. A layer of cupric oxide was grown on the polished glass surface and its thickness measured using a scanning electron microscope (SEM). The thickness of the oxide layer was found to increase parabolically with time, with a temperature dependency that was compatible with the diffusion of copper through the layer. The cupric oxide layer was reduced to copper on roughened and polished glass surfaces using a gas mixture of 3% H₂ and 97% N₂, resulting in a glass substrate coated by copper. Adherence of the copper layer to the polished glass substrate was found to be poor. However, adherence was found to increase by roughening the surface before oxidation. Additions of NiO and CaO to the base glass were not detrimental to the production of the copper film.

APA, Harvard, Vancouver, ISO, and other styles

29

Arnold, Rebecca. "Earthworm - copper interactions." Thesis, University of Reading, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.430943.

Full text

APA, Harvard, Vancouver, ISO, and other styles

30

Faughan, Marian. "Copper and haemostasis." Thesis, University of Ulster, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.284849.

Full text

APA, Harvard, Vancouver, ISO, and other styles

31

Garcia-Vazquez, Valentin. "Copper oxide superconductors." Diss., The University of Arizona, 1992. http://hdl.handle.net/10150/185961.

Full text

Abstract:

The properties of superconducting YBa₂Cu₃O₇₋(δ) thin films have been studied. Films have been prepared by multilayer deposition followed by ex situ furnace annealing. Deposition consists of a combination of dc triode sputtering from metallic targets of Y and Cu and thermal evaporation from a BaF₂ source. Superconducting and structural properties of the films strongly depend on the annealing conditions. Several heat treatment cycles were investigated, as well as different compositions. Best results were obtained for films deposited on (100) SrTiO₃ substrates, exhibiting T(c)(onset) as high as 92 K and zero resistance by 85 K. The second part of this dissertation examines the properties of ceramic Nd₂₋ₓCeₓCuO₄₋(δ) and Nd₁ͺ₈₅Ce₀ͺ₁₅(Cu₁₋(y)Zn(y))O₄₋(δ) bulk samples. Superconducting properties are examined as a function of x and y. Accurate (± 0.001 Å) lattice parameter calculations are performed from experimental x-ray diffraction data. Comparisons with previous zinc-doping studies in the hole superconducting material La₁ͺ₈₅Sr₀ͺ₁₅CuO₄₋(δ) are made. Theoretical implications and the question of electron-hole symmetry in the copper oxide superconductors are also discussed.

APA, Harvard, Vancouver, ISO, and other styles

32

Lu, Zheng-Ya. "Extraction of copper from copper-iron and copper-nickel-iron sulfide concentrates by a double roast-leach process." Thesis, Lu, Zheng-Ya (1986) Extraction of copper from copper-iron and copper-nickel-iron sulfide concentrates by a double roast-leach process. PhD thesis, Murdoch University, 1986. https://researchrepository.murdoch.edu.au/id/eprint/52722/.

Full text

Abstract:

A fundamental investigation into a double roast-leaeh process to extract copper from sulfide concentrates containing iron and nickel has been undertaken. The double roast-leach process involves three steps: dead roast to remove sulfur from concentrates, segregation roast to produce metallic copper, and a selective leach of copper with acidic Cu(II) sulfate/acetonitrile (AN)/H20 or Cu(II) chloride/NaCl/h2O solutions. The first part of this work investigates the application of the double roast-leach process for -the recovery of copper from copper-iron and copper-nickel-iron sulfides under a variety of roast conditions. The extent of sulfur removal from the calcine and the formation of copper ferrite were studied to test their effect on the subsequent leaching and recovery of copper. It was found that sulfur in the calcine tends to hold copper as CuS and decrease the copper recovered by leaching, whi1st the formation of ferrite has less effect on the subsequent segregation and copper leaching. A study of the effect of temperature, carbon addition, chloride addition and time on segregation roasting revealed that with about 10% carbon addition, a high efficiency of copper segregation and leaching was achieved over a relatively wide range of roasting temperatures and leaching conditions. However strict control of the roasting temperature to about 670C and carbon addition was necessary to achieve selective segregation and extraction of copper from nickel and iron-bearing sulfide concentrates. The second part of this work compares and contrasts the dissolution rates and mechanism of copper and nickel metals, NiO, Fe3O4, CuFe204 and NiFe2O4 which are the components of the segregated calcine in both the Cu(II) sulfate/AN/H20 and Cu(II) chloride leach solution systems. Both electrochemical and kinetic studies were carried out on pure synthetic minerals by using rotating disc electrodes under controlled potentials and by leaching the minerals in various leach solutions of different Eh. Both approaches complemented each other and gave good agreement and correlation. It was found that the dissolution rate of copper in both the aqueous chloride and aqueous AN/sulfate leach systems was determined by Cu(II) diffusion. The dissolution rate of nickel in aqueous chloride solutions was also determined by Cu(II) diffusion, but in aqueous AN/ sulfate solutions it was inhibited by the passivation of the nickel surface. However, under practical leach conditions there is sufficient chloride present in the segregated calcine to prevent passivation from occurring. In the absence of nickel passivation the dissolution of nickel was also controlled by Cu(II) diffusion in sulfate media. By contrast, the dissolution of magnetite was found to be affected mainly by the redox potential and proton activity(aH+)of the solution and basically unaffected by stirring. Magnetite reacted most rapidly in the presence of Cu(I) at potentials cathodic to its rest potential, and the reaction rate was directly proportional to aH+. Thus to minimise the dissolution of magnetite it was necessary to leach the calcine at high Eh and high pH. The dissolution rates of hematite and nickel, copper and zinc ferrites were determined in dilute HC1. As found with magnetite, reducing agents such as Cu(I) favoured the acid dissolution of hematite but hindered the dissolution of nickel(II) oxide. This was supported by cyclic voltammogram studies of carbon pastes of and ferrites these materials. Overall, it was established that both acidic Cu(II) sulfate/AN/ H20 and Cu(II) chloride/NaCl/H20 solutions are suitable for selective leaching of copper following double roasting.

APA, Harvard, Vancouver, ISO, and other styles

33

Xue, Wei. "Investigation of reacted copper(II) species in micronized copper treated wood." Thesis, University of British Columbia, 2015. http://hdl.handle.net/2429/53943.

Full text

Abstract:

Wood preservatives using micronized particulate copper as the active ingredient recently introduced in the USA has generated controversies due to their limited intrinsic solubility compared to the conventional soluble copper treatments. Because the availability of soluble copper ions is essential for these preservatives to provide an effective treatment, concerns are centered on whether they are able to produce soluble copper, and the copper fixation mechanism of the treatment is little understood. In this thesis, micronized copper treated wood were studied using a combination of Electron Paramagnetic Resonance (EPR) spectroscopy and X-ray Fluorescence (XRF) spectroscopy. The identification and characterization of soluble and chemically fixed copper species were discussed. A calibration standard was developed to quantify the solubilized and fixed copper species in the micronized copper treated wood, which also contains unreacted particulate copper. On the basis of the experimental results, the fixation mechanism is thought to be triggered by the reaction between the carboxylic acid protons in hemicellulose and pectin of wood with the particulate copper, and the quantities of the solubilized and fixed copper species are determined by the availability of the acidic protons. Results from the studies on micronized copper treated earlywood and latewood, as well as the effect of monoethanolamine additive provided further support on the theory of the fixation mechanism. Soil exposure experiment suggested that the Cu fixation may be affected by the moisture level, organic content and metal content in the soil. Study on micronized copper treated heartwood showed that the particulate Cu may react with the resin acids in addition to the major wood components. The effects of fungal colonization and bio-incision on the pre-treatment material were also briefly discussed.
Science, Faculty of
Chemistry, Department of
Graduate

APA, Harvard, Vancouver, ISO, and other styles

34

McEachern, Ernest J. "Copper(I) chloride and copper(I) cyanide-mediated transformations of alkenyltrialkylstannanes." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq25110.pdf.

Full text

APA, Harvard, Vancouver, ISO, and other styles

35

Emera, Flory. "Method development for copper dispersion evaluation and copper-based catalysts characterization." Thesis, Uppsala universitet, Strukturkemi, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-206922.

Full text

Abstract:

N2O chemisorption technique for copper dispersion determination was developed and optimized for accurate and reproducible results. With this technique, the bulk oxidation of pre-reduced catalyst can be prevented by N2O decomposition at low temperature (30oC). Only surface copper atoms are oxidized. The amount of freshly oxidized surface coppers is determined from H2-back-titration of fixed oxygen.The impact of temperature and time of exposure during oxidation was studied. Measurements made at higher temperature (60oC) resulted in overestimation of copper dispersion due to oxygen diffusion into the bulk and sub-layers. Much longer exposure time may also have an impact on copper dispersion estimation.For accurate results and good precision, it is recommended to work under mild conditions (isothermal oxidation at 30oC for 45 min.The developed method was successfully applied to fresh and spent catalyst. As expected, the copper dispersion for fresh catalyst was significantly higher than copper dispersion for spent catalyst.

APA, Harvard, Vancouver, ISO, and other styles

36

Ofstad, Johannes. "Ferromagnetic Resonance Spectroscopy Studies of Permalloy/Copper/Chromium/Copper thin films." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for fysikk, 2014. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-24417.

Full text

Abstract:

A theroretical and experimental study of 10Py/10Cu, 10Py/10Cu/xCr/10Cu (with x=4,7, 10,13 nm) thin films has been performed. The thin films were fabricated by the sputter deposition technique at NTNU Nanolab and afterwards a FMR-experiment were performed on them at the temperatures 180K, 210K, 240K, 280K, 330K and 360K. The anisotropy field, exchange bias and offset field were extracted and analysed. The results revealed vastly higher magnitude of anisotropy field and exchange bias for the 4 Cr film, compared to the other samples. Under 300K, the anisotropy field of 4Cr is ~60 Oe which is about 30 times larger than anisotropy field of the other samples. The exchange bias for 4Cr is ~8 Oe, which is about 10 times larger than the exchange bias of the other samples. The significant difference in exchange bias is explained by the spin-density wave amplitude, which increases for decreasing Cr-thicknesses. However, this model does not predict the large drop-off to the 7 Cr, 10 Cr and 13 Cr samples. The measurement of PyCu revealed an exchange bias of the same order as the 7-13 Cr samples, indicating that the exchange coupling between the Py and Cr layer is very weak, since it is of the same magnitude as the PyCu film. A theoretical description of H_Res and Delta H of the system was given, but not fulfilled. Factors, mainly due to spin pumping and interface effects must be identified and adapted to the equations.

APA, Harvard, Vancouver, ISO, and other styles

37

Bai, Yun. "Additive Manufacturing of Copper via Binder Jetting of Copper Nanoparticle Inks." Diss., Virginia Tech, 2018. http://hdl.handle.net/10919/95855.

Full text

Abstract:

This work created a manufacturing process and material system based on binder jetting Additive Manufacturing to process pure copper. In order to reduce the sintered part porosity and shape distortion during sintering, the powder bed voids were filled with smaller particles to improve the powder packing density. Through the investigation of a bimodal particle size powder bed and nanoparticle binders, this work aims to develop an understanding of (i) the relationship between printed part properties and powder bed particle size distribution, and (ii) the binder-powder interaction and printed primitive formation in binder jetting of metals. Bimodal powder mixtures created by mixing a coarse powder with a finer powder were investigated. Compared to the parts printed with the monosized fine powder constituent, the use of a bimodal powder mixture improved the powder flowability and packing density, and therefore increased the green part density (8.2%), reduced the sintering shrinkage (6.4%), and increased the sintered density (4.0%). The deposition of nanoparticles to the powder bed voids was achieved by three different metal binders: (i) a nanoparticles suspension in an existing organic binder, (ii) an inorganic nanosuspension, and (iii) a Metal-Organic-Decomposition ink. The use of nanoparticle binders improved the green part density and reduced the sintering shrinkage, which has led to an improved sintered density when high binder saturation ratios were used. A new binding mechanism based on sintering the jetted metal nanoparticles was demonstrated to be capable of (i) providing a permanent bonding for powders to improve the printed part structural integrity, and (ii) eliminating the need for organic adhesives to improve the printed part purity. Finally, the binder-powder interaction was studied by an experimental approach based on sessile drop goniometry on a powder bed. The dynamic contact angle of binder wetting capillary pores was calculated based on the binder penetration time, and used to describe the powder permeability and understand the binder penetration depth. This gained understanding was then used to study how the nanoparticle solid loading in a binder affect the binder-powder interactions and the printed primitive size, which provided an understanding for determining material compatibility and printing parameters in binder jetting.
PHD

APA, Harvard, Vancouver, ISO, and other styles

38

Gill, Paul Anthony. "Some aspects of copper thioneins in chronic copper poisoning of sheep." Thesis, Gill, Paul Anthony (1990) Some aspects of copper thioneins in chronic copper poisoning of sheep. PhD thesis, Murdoch University, 1990. https://researchrepository.murdoch.edu.au/id/eprint/53328/.

Full text

Abstract:

This thesis reports on investigation of the roles of metallothionein and lysosomal enzymes in the pathogenesis of chronic Cu poisoning of sheep, with and without treatment by thiomolybdates. The changes in copper, zinc and molybdenum distribution were studied in the liver, bile, kidney and blood of chronic Cu poisoned sheep using histochemical, immunohistochemical and biochemical techniques including gel filtration and subcellular fractionation. Morphological changes, particularly in the liver and kidney were investigated using light and electron microscopy. The results of gel filtrations of liver indicated that metallothioneins were the main Cu binding protein in the cytosol and lysosomal rich mitochondrial fractions. Examination of kidneys showed that metallothionein was the most important Cu storage protein in that organ. Most of the Cu in the bile of chronic Cu poisoned sheep was bound to high molecular weight proteins. Small amounts of Cu thionein-like protein were detected in the bile just prior to and during haemolysis. It appears that thiomolybdate altered the binding of Cu so that it associated with more proteins than it normally does. Metallothionein mRNA determinations suggested a·correlation between liver Zn concentration and metallothionein mRNA. Increased intracellular Cu concentrations associated with either haemolysis or thiomolybdate treatment resulted in decreased Cu extractability. Thiomolybdate appeared to alter the binding of Cu by the formation of high molecular weight complexes most of which were insoluble. Studies with radiolabelled metallothionein showed that intravenously injected metallothionein was taken up at two sites - the kidney and the lung. Injected metallothionein did not appear to damage the tubular epithelial cells. Traces of metallothionein (Fraction III) appeared to be present in cell free lysates of erythrocytes taken from sheep in haemolysis though most of the Cu in the plasma and erythrocytes collected du'.ing the prehaemolytic and haemolytic phases of chronic Cu poisoning was bound to high molecular weight proteins. It is suggested that neither Cu thioneins nor haemoglobin, both of which are in the blood at haemolysis, cause serious damage to the kidney. However, both normal and iron loaded sheep kidneys were found to be an important site of uptake of a radiolabelled lysosomal enzyme preparation. The uptake of lysosomal enzymes may be an important causal factor in producing the clinically significant damage to sheep kidney which often occurs during the haemolytic phase of chronic Cu poisoning.

APA, Harvard, Vancouver, ISO, and other styles

39

Hamilton, M. A. "The optical properties of oxide films on copper and copper alloys." Thesis, London Metropolitan University, 1985. http://repository.londonmet.ac.uk/3378/.

Full text

Abstract:

Suitable conditions were selected to allow thin, thermal oxide films consisting of cuprous oxide only to be grown on copper and dilute copper alloy substrates. The identity of the oxide was confirmed by x-ray diffraction and coulometry. Spectral measurements covering the wavelength range 350 - 750 nm were made using an automatic, self-nulling ellipsometer. From this data the optical constants and thickness of the oxide films were computed and compared to those of the bulk oxide. The optical constants of the oxide were found to depend on the thickness of the film and the identity of the alloying addition in the substrate. The effect of different substrates on the optical constants of cuprous oxide was tested by growing thin cuprous oxide films on gold and glass substrates. Optical property changes of the oxide are attributed to space-charge effects existing at the substrate/oxide interface.

APA, Harvard, Vancouver, ISO, and other styles

40

Andersson, Isabel. "Our body body as an expressive tool." Thesis, Umeå universitet, Designhögskolan vid Umeå universitet, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-140111.

Full text

Abstract:

Humans were made to move. Many hours in front of a screen leads to stiff bodies and a diminished bodily awareness. The aim of this project was to explore how technology can serve to increase our body awareness and adapt to our physical conditions in everyday life with focus on office spaces. The study is explorative with a user-centered approach and a focus on embodied prototyping, where the user is a subject of design. Data was collected with recordings, interviews, and workshops. Reflexion-on-action, prototyping and iterations lead to the final outcome. The final concept is a wearable that encourage people to move and stretch out more often and spontaneously throughout the day. It does so by vibration patterns along your spine and shoulders. The idea of this concepts is to make people move often and regularly during the day; to react spontaneously to a reminder from the body, mediated by the vibrations. The system is thought to be self-awarding; if it feels good to stretch out, to extend the arms, to move – then you will want to do it again.

APA, Harvard, Vancouver, ISO, and other styles

41

Lodder, Matthew C. "Body Art : Body Modification as Artistic Practice." Thesis, University of Reading, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.525734.

Full text

Abstract:

This thesis is an investigation into the legitimacy and limits of the term "body art" in its vernacular sense, wherein it refers to methods of decorating or ornamenting the body, such as tattooing or piercing. Though the term is widely used and widely understood, it has rarely appeared in any writing which takes an explicitly arthistorical or art-critical approach, and has never been subjected to any sustained analysis which uses the methodologies deployed by specialists when engaging with other forms of art. If tattooing and its coincident technologies are "body art", they have not as yet been understood as such by art historians. The arguments made over the course of this work thus amount to a case for the applicability of art-historical and art-theoretical methodologies to body modification practice. The thesis first establishes the existence of a rhetorical yet broadly undefended case for the artistic status of practices which alter the form of the body. This claim is to be found amongst both the contemporary subcultural body modification community and amongst plastic surgeons. With particular reference to theories of art and aesthetics by John Dewey, Richard Shusterman, and Gilles Deleuze and Felix Guattari, the work investigates whether such claims are tenable. In light of these investigations, the thesis then presents a number of problems which immediately arise from such a claim - problems of authorship, ownership, objectivity and value - and attempts to resolve them through detailed analysis of a number of case-studies.

APA, Harvard, Vancouver, ISO, and other styles

42

Craig, Pippa. "Which body size? : a cross-cultural study of body composition and body perception." Phd thesis, Faculty of Medicine, 1999. http://hdl.handle.net/2123/12824.

Full text

APA, Harvard, Vancouver, ISO, and other styles

43

BELLAN, VALERIA. "Body representation, body localisation and body size perception: a study of bodily modulations." Doctoral thesis, Università degli Studi di Milano-Bicocca, 2015. http://hdl.handle.net/10281/69677.

Full text

Abstract:

People are generally quite good at adapting to changes in body shape and size because of the flexibility of the body representation. By means of bodily illusions, it is possible to experimentally induce updating of body representation and, thus, manipulate the sense of self. The main aim of this thesis is to investigate the sense of self through bodily illusions. Firstly, we investigated the relationship between the sense of ownership and self-localisation (Study 1). The results from this study are taken to suggest that the proprioceptive drift (i.e. a bias in the localisation of a given body part) is more likely triggered by and related to the visual capture of touch than it is a reliable measure of a shift in the sense of body ownership. In fact, our data show that the proprioceptive drift occurs not only in the absence of a shift in the sense of ownership, but even in the absence of a body-like object. Secondly, we investigated self-localisation of body parts by means of a novel illusion, the Disappearing Hand Trick. In particular, we explored the role of vision and proprioception (Study 2), as well as the role of attention and motor acts (Study 3), in locating one’s own hands when visual and proprioceptive information regarding the body are incongruent. Our data (Study 2) are in line with previous research, confirming a predominant role of vision over proprioception. In addition, they show that, after a certain amount of time, proprioception is weighted more heavily than vision. That is, our results demonstrate that the cortical proprioceptive representations can be updated even when there is no real need to do it (i.e. no movement is required). This might be seen as an evolutionarily convenient response to keep the body ready for a possible quick reaction. In Study 3, we ruled out the possibility that this effect was only driven by spatial attention being directed towards the side of the space where the hand was actually located. In fact, no difference in the localisation accuracy was found when the direction of spatial attention was manipulated. Finally, by asking the participants to reach across for their hidden right hand (Study 3), we confirmed that a motor act accelerates the reliance on proprioception, most likely by aligning the motor and perceptual coordinates in order to plan the movement. In the first three studies, a modification of the body representation was intentionally induced – namely, the purpose of the illusions was to change how the participants perceived their body. However, we wondered whether this same change might also occur at a more implicit level and how rapidly this may occur. We designed two different studies in which we tried to manipulate the participants’ perceived body size by providing incongruent information about the position of their limb (Study 4) or by showing the participants images of unrealistic bodies (Study 5). In Study 4 we showed that incongruent proprioceptive information coming from the same joint does not affect the perceived size of that body part, but does lead to a more accurate estimation of its position. On the other hand, the results of Study 5 would seem to suggest that body perception is more vulnerable to change in women than in men after exposure to same-sex ideal bodies. Taken together, these results suggest that, by manipulating the body representation, both explicitly, by means of a variety of bodily illusion, and even implicitly, by generating subtle incongruence between one’s own real body and how the body ‘should’ be, we were able to shed some light on the mechanisms behind the computation of body position and size, both of which are important elements for the definition of the self.

APA, Harvard, Vancouver, ISO, and other styles

44

Jonnalagadda, Krishna Praveen. "Influence of Graphite type on copper diffusion in P/M copper steels." Thesis, KTH, Materialens processteknologi, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-98264.

Full text

Abstract:

One main reason for the use of Fe-Cu-C system in PM industry is the presence of liquid phase (copper) at the start of sintering (1120oC). The diffusion of liquid copper into iron causes swelling in the structure. This in turn can cause high dimensional change and, if not controlled properly, may cause distortion. So it is of paramount importance to control the copper diffusion. Carbon, added as graphite, reduces the swelling of copper by changing the dihedral angle. The affect of graphite on copper diffusion depends on the graphite type, particle size of graphite and heating rate. The aim of this work was to find the influence of graphite type and particle size of graphite on copper diffusion. Water Atomized iron (ASC100.29) produced in Höganäs AB was taken as the base powder. Two types of graphite were used each with two different particle sizes. Two different graphite quantities (0.2% & 0.8%) for each type was taken. Natural fine graphite (UF4), Natural coarse graphite (PG44), Synthetic fine graphite (F10) and Synthetic coarse graphite (KS44) were the graphites used in this work. Powders were compacted at 600 Mpa and the sintering was done at 1120oC for 30 minutes in 90/10 N2/H2. Dilatometry and metallographic investigation of the samples sintered in the production furnace were used to understand the graphite influence. The investigation showed that at low graphite levels (0.2%), the affect of graphite type or graphite size was not significant on copper diffusion. At high graphite levels (0.8%), synthetic graphites were more effective in reducing the swelling of copper. Influence of particle size of synthetic graphites on Cu diffusion was not significant compared to the influence of particle size of natural graphite. There was also a considerable affect of heating rate on graphite dissolution and copper swelling.

APA, Harvard, Vancouver, ISO, and other styles

45

Khan, Sadia Arefin. "Electromigration analysis of high current carrying adhesive-based copper-to-copper interconnections." Thesis, Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/44885.

Full text

Abstract:

"More Than Moore's Law" is the driving principle for the electronic packaging industry. This principle focuses on system integration instead of transistor density in order to achieve faster, thinner, and smarter electronic devices at a low cost. A core area of electronics packaging is interconnection technology, which enables ultra-miniaturization and high functional density. Solder bump technology is one of the original, and most common interconnection methods for flip chips. With growing demand for finer pitch and higher number of I/Os, solder bumps have been forced to smaller dimensions and therefore, are subjected to higher current densities. However, the technology is now reaching its fundamental limitations in terms of pitch, processability, and current-handling due to electromigration. Electromigration in solder bumps is one of the major causes of device failures. It is accelerated by many factors, one of which is current crowding. Current crowding is the non-uniform distribution of current at the interface of the solder bump and under-bump metallurgy, resulting in an increase in local current density and temperature. These factors, along with the formation of intermetallic compounds, can lead to voiding and ultimately failure. Electromigration in solder bumps has prevented pitch-scaling below 180-210 microns, producing a shift in the packaging industry to other interconnection approaches, specifically copper pillars with solder. This research aims to explore the electromigration resistance of an adhesive-based copper-to-copper (Cu-Cu) interconnection method without solder, which is thermo-compression bonded at a low temperature of 180C. While solder bumps are more susceptible to electromigration, Cu is capable of handling two orders of magnitude higher current density. This makes it an ideal candidate for next generation flip chip interconnections. Using finite element analysis, the current crowding and joule heating effects were evaluated for a 30 micron diameter Cu-Cu interconnection in comparison with two existing flip chip interconnection techniques, Cu pillar with solder and Pb-free solder. A test vehicle (TV) was fabricated for experimental analysis with 760 bumps arranged in an area-array format with a bump diameter of 30 micron. Thermo-mechanical reliability of the test vehicle was validated under thermal cycling from -55C to 125C. The Cu-Cu interconnections were then subjected to high current and temperature stress from 1E4 to 1E6 amps per square centimeter at a temperature of 130C. The results establish the high thermo-mechanical reliability and high electromigration resistance of the proposed Cu-Cu interconnection technology.

APA, Harvard, Vancouver, ISO, and other styles

46

Legault, Richard. "Pressure induced phase transitions in copper (I) oxide and copper (II) oxide." Thesis, University of Ottawa (Canada), 1995. http://hdl.handle.net/10393/10077.

Full text

Abstract:

We have studied samples of CuO and Cu$\sb2$O to pressures of 60 GPa and 35 GPa, respectively, using energy dispersive X-ray diffraction. Samples were studied using a gasketed diamond anvil cell, energy dispersive X-ray diffraction at the Cornell High Energy Synchrotron Source, with a Mo or Al$\sb2$O$\sb3$:Cr$\sp{3+}$ pressure gauge. In the case of Cu$\sb2$O, the two phase transitions, (cubic to hexagonal to another hexagonal) as expected were seen. In CuO no definite phase transition was seen, although indications are given for CuO at 60 GPa converting to a distorted rocksalt-type structure from the initial monoclinic structure. The volume data obtained from the pressure experiments on CuO were best fitted with the third-order Birch-Murnaghan equation of state with B$\sb0$ = 110 GPa and B$\sb0\sp\prime$ = 5.5.

APA, Harvard, Vancouver, ISO, and other styles

47

Morante, Susan Janet. "The uptake of pentachlorophenol, chromated copper arsenate and copper naphthenate by soils." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ34980.pdf.

Full text

APA, Harvard, Vancouver, ISO, and other styles

48

Bell, Thomas Allen. "Copper uptake and toxicity in tilapia Oreochromis niloticus exposed to copper sulphate." Thesis, University of Stirling, 1996. http://hdl.handle.net/1893/1835.

Full text

Abstract:

The copper uptake and toxicity of young and market-size tilapia, Oreochromis niloticus, exposed to copper sulP'hate were investigated. A series of preliminary experiments were conducted to provide requisite information for the final experiment. Preliminary experiments established uptake by the culture systems, feed and/or faeces, and. the impact of fish nutritional state on uptake. Other experiments established the median lethal concentration of copper to this species, an extrapolated minimal lethal concentration, and the optimum exposure duration and concentration for copper uptake. The remaining preliminary experiments defined the relationship between toxicity and uptake in small compared to market-size tilapia, and between muscle location (within the fillet) and copper uptake. The final experiment established the amount of copper uptake in the edible tissue of market-size tilapia after a worst-case exposure to copper sulphate. The worst-case was defined as the maximum non-lethal concentration for a period significantly exceeding that encountered in commercial production systems. The worst-case experiment comprised market-size fish (350 to 570 g) being exposed at a nominal concentration of 365 ppb copper for nine days. This study demonstrated that copper did not accumulate in the edible tissue of tilapia above that measured in non-exposed control fish. A mean level of copper in the edible muscle of non-exposed fish, as measured by atomic absorption spectometry, was 2.14 pprn (dry page weight basis), while in fish exposed to a nominal concentration of 365 ppb of copper it was found to be 2.31 ppm. These data are suitable for incorporation into a United States Food and Drug Administration, New Animal Drug Approval application for the approval of copper sulphate use as a drug for aquatic species.

APA, Harvard, Vancouver, ISO, and other styles

49

Noh, Kyungyoon. "Modeling of dielectric erosion and copper dishing in copper chemical-mechanical polishing." Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/32393.

Full text

Abstract:

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2005.
Includes bibliographical references.
The phenomenal success in the manufacture of multi-layer, Ultra-Large-Scale-Integrated (ULSI) semiconductor devices is in part due to the local and global planarization capabilities of the chemical-mechanical polishing (CMP) process. At present, copper is widely used as the interconnect material in the ULSI technology. The greatest challenge in Cu CMP now is the control of wafer surface non-uniformity-primarily due to dielectric erosion and copper dishing at various scales--to within the ever stringent industry specifications. In this thesis, an integrated non-uniformity model is developed by combining wafer-, die- and feature-scale non-uniformities. A feature-scale pressure calculation scheme based on surface step-height is adopted, and the evolution of the surface in each polishing stage is modeled in terms of geometric, material and process parameters. Various pad/wafer contact mechanics regimes have been considered to model oxide erosion and Cu dishing, from submicron device level to the global wiring level. The plausible causes of erosion and dishing at wafer-, die- and feature-scales were identified and integrated into the feature-scale step-height models. Such parameters include: initial pattern geometry, wafer-scale uniformity, and Cu-to-oxide slurry selectivity, material properties, and surface topography of the pad. Based on the developed erosion and dishing models, the effects of model parameters on the wafer-surface non-uniformity in Cu CMP are discussed, and parameter sets to satisfy both dishing and erosion specifications are obtained.
(cont.) In single-step polishing, for example, the Cu deposition factor should be less than 0.1 and the wafer-scale uniformity factor needs to be greater than 0.95 to maintain both erosion and dishing within 5% of interconnect thickness across the wafer if the polishing slurry has a selectivity of 15. Results of polishing experiments on 100 mm patterned Cu wafers validated both the step- height models and the integrated non-uniformity model. Based on the present models, erosion and dishing across the wafer was bounded by predefined parameters. Additionally, as predicted by the models, it was observed that the step-heights of the slowest and the fastest dies evolve in the ratio of the wafer-scale uniformity factor.
by Kyungyoon Noh.
Ph.D.

APA, Harvard, Vancouver, ISO, and other styles

50

Poudyal, Kharel Aryashree. "Pyrolysis Studies of Copper and Copper Phosphate Mixtures on a Tungsten Surface." Thesis, Southern Illinois University at Edwardsville, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10016914.

Full text

Abstract:

The purpose of this research is to identify the chemical species present on a tungsten filament atomizer in the moment prior to the atomization. The first sample prepared was used to investigate the effects of copper samples with phosphate modifier and the second sample investigated the effect of copper samples with pyrophosphate. The aim of this thesis is to investigate the thermal decomposition of copper phosphate on a tungsten surface. An alumina crucible was used to understand the role of tungsten. The project sought to identify the possible copper compounds that remain after drying and pyrolysis in electrothermal atomic absorption spectroscopy. This was carried out by examining the effect of mass loss with the time and temperature. Dry sample residues, prior to and following heating, were studied using thermogravimetric analysis (TGA). X-ray diffraction showed that the starting material before performing TGA analysis was copper phosphate hydrate. The observation showed the formation of copper pyrophosphate at around 600°C for different concentrations of sample prepared. The X-ray diffraction (X-RD) spectra from TGA confirmed the formation of crystalline copper pyrophosphate at around 600 °C. The well separated endo thermal effects correlate to the mass loss steps and characterize thermal behavior of copper pyrophosphate.

APA, Harvard, Vancouver, ISO, and other styles

Dissertations / Theses on the topic 'Copper in the body'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles