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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.
31

Impact of Galvanic Corrosion on Lead Release after Partial Lead Service Line Replacement

Zhou, Emily Mi 11 December 2013 (has links)
The EPA Lead and Copper Rule set action limits for lead and copper concentrations in drinking water, but accelerated corrosion of lead in distribution systems due to a galvanic connection to copper. Prior research has demonstrated that the effects of galvanic corrosion can be controlled by water chemistry. This study not only investigated the main effects of alkalinity, natural organic matter (NOM), nitrate, disinfectant and inhibitor to galvanic corrosion, but also the interplay between these factors. A 2-level factorial (2v5-1) design was adopted which resulted in 16 testing conditions. Results of bench-scale experiments using static pipes with lead and copper segments demonstrated that alkalinity, disinfectant, inhibitor and alkalinity-inhibitor interaction had a significant impact on galvanic current. The significant factors affecting total lead release were alkalinity, NOM, disinfectant, alkalinity-inhibitor interaction, NOM-nitrate interaction, NOM-disinfectant interaction, NOM-inhibitor interaction, nitrate-disinfectant interaction and disinfectant-inhibitor interaction.
32

Impact of Galvanic Corrosion on Lead Release after Partial Lead Service Line Replacement

Zhou, Emily Mi 11 December 2013 (has links)
The EPA Lead and Copper Rule set action limits for lead and copper concentrations in drinking water, but accelerated corrosion of lead in distribution systems due to a galvanic connection to copper. Prior research has demonstrated that the effects of galvanic corrosion can be controlled by water chemistry. This study not only investigated the main effects of alkalinity, natural organic matter (NOM), nitrate, disinfectant and inhibitor to galvanic corrosion, but also the interplay between these factors. A 2-level factorial (2v5-1) design was adopted which resulted in 16 testing conditions. Results of bench-scale experiments using static pipes with lead and copper segments demonstrated that alkalinity, disinfectant, inhibitor and alkalinity-inhibitor interaction had a significant impact on galvanic current. The significant factors affecting total lead release were alkalinity, NOM, disinfectant, alkalinity-inhibitor interaction, NOM-nitrate interaction, NOM-disinfectant interaction, NOM-inhibitor interaction, nitrate-disinfectant interaction and disinfectant-inhibitor interaction.
33

Repair and corrosion management of reinforced concrete structures

Christodoulou, Christian January 2013 (has links)
The durability of concrete structures is affected by a number of factors such as environmental exposure, electrochemical reactions, mechanical loading, impact damage and others. Of all of these, corrosion of the reinforcement is probably the main cause for the deterioration of steel reinforced concrete (RC) structures. Corrosion management is becoming increasingly necessary as a result of the growing number of ageing infrastructure assets (e.g. bridges, tunnels etc.) and the increased requirement for unplanned maintenance in order to keep these structures operational throughout their design life (and commonly, beyond). The main RC repair, refurbishment and rehabilitation approaches generally employed can be broadly categorised under a) conventional, b) surface treatments, c) electrochemical treatments and d) design solutions. The overarching aim of this research was to identify the key corrosion management techniques and undertake empirical investigations focused on full-scale RC structures to investigate their long-term performance. To achieve this, individual research packages were identified from the above broad five approaches for repair, replacement and rehabilitation. These were 1) Patch repairs and incipient anodes, 2) Impressed Current Cathodic Protection, 3) Galvanic Cathodic Protection and 4) Hydrophobic treatments. The selection of the above research packages was based on past and present use by the construction industry to repair, refurbish and rehabilitate RC structures. Their contributions may be broadly categorised as i) Investigations on how specific treatments and materials perform, ii) Investigations on the effectiveness of existing methods of measurements and developing alternatives, iii) Changes to the existing theory of corrosion initiation and arrest and iv) Changes to management framework strategies. The key findings from each research package can be summarised as follows: Macrocell activity appears to be a consequence rather than a cause of incipient anode formation in repaired concrete structures, as has previously been presented; ICCP has persistent protective effects even after interruption of the protective current; Discrete galvanic anodes installed in the parent concrete surrounding the patch repair are a feasible alternative to galvanic anodes embedded within the patch repairs of RC structures; Silanes may have a residual hydrophobic effect even after 20 years of service.
34

The Role of the Monkey Amygdala in the Autonomic Expression of Emotion

Spitler, Kevin M. January 2007 (has links)
The skin conductance response is involved in the preparation for and response to stimuli with emotional significance. The neural mechanisms responsible for the generation of the skin conductance response are not well understood despite the common use of this signal as an index of emotional response. Data from anatomical, lesion, and neuroimaging studies in humans suggest that the amygdala, a component of the brain circuit for emotion, plays a critical role in the generation of the skin conductance response. Here we employ a novel combination of existing techniques to understand the stimuli that elicit skin conductance responses in the monkey and the neural mechanisms in the amygdala that participate in its generation. We recorded skin conductance responses in monkeys trained to perform a passive image viewing task. This paradigm is a staple of human emotion research but to date has not been adapted to the monkey. In addition, skin conductance responses to these stimuli were recorded in conjunction with single unit responses from the amygdala. This study addresses the relationship between the activity of single neurons recorded from identified nuclei of the monkey amygdala and autonomic responses. Neurons in multiple nuclei of the amygdala showed reliable changes in neuronal discharge prior to the skin conductance response. These neurons were primarily in the dorsal nuclei of the amygdala, which confirms predictions made from anatomical and neuroimaging data. It is suggested that these changes in neuronal discharge may correspond to the generation of this autonomic component of the expression of emotion.
35

A pupillometric study of deception

Ertas, Metin January 1973 (has links)
The sensitivity of pupillary responses (PR) to emotional states brought on by psychological state of deception was explored. Utilizing a combination of guilty person and guilty knowledge techniques, 16 male and 14 female Ss were presented with neutral and relevant names, with relevant names involving deception. Half of the Ss were presented with one relevant name and the other half were presented with two. The lists of five names were presented on three trials during which PR and GSR were monitored. Pupiliary responses and GSRs to relevant names were significantly different than PRs and GSRs to neutral names. There were no significant effects with respect to the number of relevant names and trials. In terms of detection rates, GSR yielded higher rates than PR. The correlational tests indicated no significant relationship between PR and GSR under the experimental conditions employed.
36

Electrodermal indices of information processing and functional cerebral asymmetry in schizophrenia : a comparison with affective disorder /

Carr, Vaughan. January 1987 (has links) (PDF)
Thesis (M.D.)--University of Adelaide, Dept. of Psychiatry, 1987. / Includes bibliographical references (leaves 350-389).
37

The voltage-current characteristic of the human skin

Lochner, Georg Philip. January 2005 (has links)
Thesis (M.Eng.(Bio-Engineering))--University of Pretoria, 2003. / Summaries in Afrikaans and English. Includes bibliographical references.
38

An investigation of the difference in psychogalvanic skin response as a result of frustration between educable mentally retarded and intellectually normal boys

David, William Joseph, January 1966 (has links)
Thesis (Ph. D.)--University of Wisconsin, 1966. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliography.
39

Geração de resíduos sólidos de galvanoplastia em regiões densamente povoadas - avaliação, inertização e destinação / Production of solid galvanic waste in densely populated areas - evaluation, inertization and disposal

MATTOS, CLEITON dos S. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:33:36Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:04:02Z (GMT). No. of bitstreams: 0 / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP
40

Estudo de rejeitos de galvanoplastia e a sua aplicação na fabricação de peças cerâmicas rústicas para fins decorativos /

Delbianco, Gislaine Aparecida Barana. January 2008 (has links)
Orientador: Maria Margarita Torres Moreno / Banca: Antenor Zanardo / Banca: Tamar Milca Bortolozzo Galembeck / Banca: Flavio Machado de Souza Carvalho / Banca: Sérgio R. Christofoletti / Resumo: O encapsulamento de resíduos em massas cerâmicas tem sido uma solução extremamente interessante porque permite a imobilização de resíduos tóxicos. O objetivo deste trabalho é estudar a aplicação de rejeitos de galvanoplastia às massas cerâmicas, sem o comprometimento das propriedades físico-químicas do produto final, possibilitando assim o desenvolvimento de uma cerâmica rústica, com variação de cores e boas propriedades tecnológicas. Os ensaios de caracterização das matérias primas foram a Fluorescência de Raios X, Iodometria e Difração de Raios X. Corpos de prova foram preparados por via seca, em formulações de massa variando o tipo de argila, a concentração do resíduo e o tipo de processo, foram realizados ensaios para controle das propriedades físico-químicas e para classificação de uso, de acordo com a NBR 13818/97. A análise petrográfica permitiu observar o comportamento do resíduo nos diferentes processos de preparação e os ensaios de eflorescência, lixiviação e solubilização comprovaram a inertização do resíduo. A utilização dos resíduos como aditivo apresentaram resultados bastante satisfatórios e indicam a viabilidade comercial da cerâmica rústica, pois a presença de CuO e NiO possibilitaram o aumento da vitrificação das massas cerâmicas e permitiu utilizar a argila considerada "rejeito" pelos ceramistas do Pólo de Santa Gertrudes-SP. / Abstract: The encapsulating of residues in ceramic masses has been an extremely interesting solution because it allows the immobilization of toxic residues. The objective of this paper is to study the application of wastes of galvanoplasty to the ceramic masses, without compromising the physicist-chemistries properties of the final product, thus making possible the development of rustic ceramics, with variation of colors and good technological properties. The assays of characterization of the raw materials were the X Rays Fluorescence, Iodometry and X Ray Diffraction. Samples were prepared by dry process method, in mass formularizations varying the type of clay, the concentration of the residue and the type of process, assays were carried out to know the control of physicist-chemistries properties and classification of use, according to NBR 13818/97. The petrographic analysis allowed to observe the behavior of the residue in different processes of preparation and the assays of efflorescence, leaching and solubilization had proven the inertness of the residue. The use of the residues as additive presented sufficiently satisfactory results and indicates the commercial viability of rustic ceramics; therefore the presence of CuO and NiO makes possible the increase of the vitrification of the ceramic masses and allowed to use the considered clay "waste" for the ceramists of the pole of Santa Gertrudes-SP. / Doutor

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