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Váša, Lukáš. "Parametry kabelových vedení." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2021. http://www.nusl.cz/ntk/nusl-442551.
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In recent years, the development trend of power grids character shows increased demand for using cables of both current overhead and newly constructed lines. In order to preserve reliable operation and to predict the maintenance requirements, it is crucial to regard not only the parameters certified by manufacturers, but also externalities induced by real environment and incorporate these externalities into cable models in simulation software. The diploma thesis deals with determining of characteristic parameters of single core cables in real environment, which are affected by real grounding methods of metal shielding. The emphasis is put on analysis of current cable models in simulation software PSCAD and its evaluation using two-step experiment 1) measurement of shunt parameters in laboratory using electronic bridge model and 2) on field measurement of cable series parameters in real environment.
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Hudson, Athol Peter Gilfillan. "Comparative bond strengths of stainless steel orthodontic brackets bonded with different bonding agents." Thesis, University of the Western Cape, 2007. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_4825_1256889166.
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Stahlberg, Eric Alan. "Application of multireference based correlation methods to the study of weak bonding interactions /." The Ohio State University, 1991. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487759436325374.
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Silvennoinen, H. (Hanna). "3D structure of the crust and upper mantle beneath Northern Fennoscandian shield." Doctoral thesis, University of Oulu, 2015. http://urn.fi/urn:isbn:9789526210681.
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The crustal and upper mantle structures of the Shield on the regional scale were
investigated using the data of the POLENET/LAPNET passive seismic array and
the previously published models of active and passive seismic experiments in the
study area. This area is centred in northern Finland and it extends to surrounding
areas in Sweden, Norway and northwestern Russia. The bedrock there is mostly of
the Archaean origin and the lithosphere of the region was reworked by two orogenies
during Palaeoproterozoic.
One of the results of the thesis was a new map of the Moho depth of the study area,
for which new estimates of the crustal thickness were obtained using receiver function
method and complemented by published results of receiver function studies and controlled
source seismic profiles. The map differs from the previously published maps in
two locations, where we found significant deepening of the Moho. The 3D structure of
the upper mantle was studied using teleseismic traveltime tomography method. The
resulting model shows high seismic velocities below three cratonic units of the study
area, which may correspond to non-reworked fragments of cratonic lithosphere and a
low velocity anomaly separating these cratonic units from each other.
The regional scale studies were complemented by two smaller scale studies in upper
crust level using combined interpretation of seismic profiling and gravity data. These
studies were centred on Archaean Kuhmo Greenstone Belt in eastern Finland and
central Lapland in northern Finland located in the crust reworked during Palaeoproterozoic.
Both areas are considered as prospective ones for mineral exploration. Both
studies demonstrate the advantage of gravity data inversion in studying 3D density
structure of geologically interesting formations, when the Bouguer anomaly data is
combined with a priori information from petrophysical and seismic datasets.
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Shukla, Priyank <1984>. "Machine learning methods for prediction of disulphide bonding states of cysteine residues in proteins." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2010. http://amsdottorato.unibo.it/2588/.
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The goal of this thesis work is to develop a computational method based on machine learning techniques for predicting disulfide-bonding states of cysteine residues in proteins, which is a sub-problem of a bigger and yet unsolved problem of protein structure prediction. Improvement in the prediction of disulfide bonding states of cysteine residues will help in putting a constraint in the three dimensional (3D) space of the respective protein structure, and thus will eventually help in the prediction of 3D structure of proteins. Results of this work will have direct implications in site-directed mutational studies of proteins, proteins engineering and the problem of protein folding.
We have used a combination of Artificial Neural Network (ANN) and Hidden Markov Model (HMM), the so-called Hidden Neural Network (HNN) as a machine learning technique to develop our prediction method. By using different global and local features of proteins (specifically profiles, parity of cysteine residues, average cysteine conservation, correlated mutation, sub-cellular localization, and signal peptide) as inputs and considering Eukaryotes and Prokaryotes separately we have reached to a remarkable accuracy of 94% on cysteine basis for both Eukaryotic and Prokaryotic datasets, and an accuracy of 90% and 93% on protein basis for Eukaryotic dataset and Prokaryotic dataset respectively. These accuracies are best so far ever reached by any existing prediction methods, and thus our prediction method has outperformed all the previously developed approaches and therefore is more reliable.
Most interesting part of this thesis work is the differences in the prediction performances of Eukaryotes and Prokaryotes at the basic level of input coding when ‘profile’ information was given as input to our prediction method. And one of the reasons for this we discover is the difference in the amino acid composition of the local environment of bonded and free cysteine residues in Eukaryotes and Prokaryotes. Eukaryotic bonded cysteine examples have a ‘symmetric-cysteine-rich’ environment, where as Prokaryotic bonded examples lack it.
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Braydich, Michael Dennis. "A theoretical investigation of the bonding of methylene to metal dimers using the Fenske-Hall and X[alpha] methods /." The Ohio State University, 1987. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487584612161369.
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Wu, Xianghong. "Determination of near-surface, crustal and lithospheric structures in the Canadian Precambrian Shield using time-domain electromagnetic and magnetotelluric methods." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/NQ62678.pdf.
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Lu, Chunmeng. "Development of novel micro-embossing methods and microfluidic designs for biomedical applications." Columbus, Ohio : Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1156820643.
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Lawrence, A. Raelene. "A computational investigation of inorganic systems using ab initio methods /." free to MU campus, to others for purchase, 2000. http://wwwlib.umi.com/cr/mo/fullcit?p9998495.
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Pfeifer, Lukas. "New methods and reagents for carbon-fluorine bond formation." Thesis, University of Oxford, 2016. https://ora.ox.ac.uk/objects/uuid:fe082120-eae7-4299-a349-0d42401ff501.
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After a general introduction about the properties and preparation of organofluorine compounds (Chapter 1), this thesis is divided into two parts focussing on the development of new methods for C-F bond formation (Part A) as well as studies towards the development of novel fluorinating reagents (Part B). Part A: New Methods for Carbon-Fluorine Bond Formation Part A consists of two chapters outlining the development of a Pd-catalysed hydrofluorination of alkenylarenes (Chapter 2) as well as a halofluorination of alkynes (Chapter 3). Chapter 2 This chapter describes the development of a novel, regioselective, syn-specific hydrofluorination of alkenylarenes under Pd-catalysis leading to the formation of benzylic fluorides. An extensive substrate scope is presented together with a model of the catalytic cycle, based on observations during the development of this reaction, deuterium labelling experiments as well as mechanistic control experiments starting from isolated palladacycles. Chapter 3 In this chapter the development of a novel iodo- as well as bromofluorination of internal and terminal alkynes, leading to the formation of (E)-halofluoroalkenes, is presented. For the former substrate class, the effects of steric as well as electronic bias on regioselectivity are discussed. For the latter substrate class, this methodology could be extended to the corresponding double iodofluorination, and for both transformations it was found to exclusively lead to the fluorination of the internal carbon. An extensive substrate scope as well as different iodofluorination-cross-coupling sequences including Suzuki, Sonogashira and Ullmann couplings, are illustrated. A representative reaction was successfully carried out on gram-scale and an iodofluorination-Suzuki-coupling sequence was used to prepare a fluorinated tamoxifen derivative. Part B: Hydrogen-Bonded Fluoride Complexes as Novel Reagents for Carbon-Fluorine Bond Formation Part B consists of two chapters describing structural as well as reactivity studies of fluoride-alcohol (Chapter 4) and fluoride-urea complexes (Chapter 5). Chapter 4 In this chapter the synthesis of 19 novel hydrogen-bonded tetraalkylammonium fluoride-alcohol complexes is described. For a subset of 15, the solid-state structures as determined by single-crystal X-ray diffraction experiments are presented. Trends of reactivity and selectivity were determined using these complexes as sources of fluoride anion in a model SN2 reaction. Preliminary results from in silico modelling of the fluoride-alcohol system provide a basis for explaining the results. Chapter 5 This chapter summarises the synthesis and solid-state structures of 20 hydrogen-bonded fluoride complexes using the urea and related squaramide and amide motifs. Also, the size of the tetraalkylammonium counter-cation was varied to study the influence on the solid-state structure. The reactivity and selectivity of a series of complexes was studied using the same model SN2 reaction as in Chapter 4 and results were compared accordingly. Different UV-vis and NMR spectroscopic techniques were used to study the behaviour of the fluoride-urea system in solution. Preliminary results demonstrate the use of 1,3-diarylureas as organocatalysts for nucleophilic fluorination.
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Rajapakshe, Senanayake Asha. "ELECTRONIC STRUCTURE AND BONDING FACTORS OF TRANSITION METAL - PENTADIENYL AND (FLUOROALKYL)PHOSPHINE COMPLEXES: PHOTOELECTRON SPECTROSCOPY AND COMPUTATIONAL METHODS." Diss., Tucson, Arizona : University of Arizona, 2005. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu%5Fetd%5F1220%5F1%5Fm.pdf&type=application/pdf.
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Rajitrangson, Phitakphong. "Effect of surface conditioning methods on repair bond strength of microhybrid resin matrix composite." Connect to resource online, 2010. http://hdl.handle.net/1805/2138.
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Thesis (M.S.D.)--Indiana University School of Dentistry, 2010<br>Title from PDF t. p. (viewed May 12, 2010) Advisor(s): Michael A. Cochran, Chair of the Research Committee, Jeffrey A. Platt, Bruce A. Matis, Carlos Gonzalez-Cabezas, Sopanis D. Cho. Curriculum vitae. Includes abstract. Includes bibliographical references (leaves 64-69).
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Dang, Thai Son [Verfasser], Günther [Gutachter] Meschke, and Markus [Gutachter] Thewes. "Computational methods and numerical analyses of material transport in EPB shield machines / Thai Son Dang ; Gutachter: Günther Meschke, Markus Thewes ; Fakultät für Bau- und Umweltingenieurwissenschaften." Bochum : Ruhr-Universität Bochum, 2018. http://d-nb.info/1169397344/34.
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Lamba, Nishtha. "Psychological well-being, maternal-foetal bonding and experiences of Indian surrogates." Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/271335.
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Over the past two decades, India has become an international hub of cross-border surrogacy. The extreme economic and cultural differences between international couples seeking surrogacy and the surrogates themselves, clinics compromising health of surrogates for profit, the stigmatisation of surrogacy in India, and the constant surveillance of these women living in a ‘surrogate house’, have raised concerns regarding the potentially negative psychological impact of surrogacy on Indian surrogates. The primary aims of the thesis were (i) to conduct a longitudinal assessment of surrogates’ psychological problems (anxiety, depression and stress) from pregnancy until several months after relinquishing the baby to the intended parents, (ii) to examine the nature of the bond formed between surrogates and the unborn baby and establish whether this prenatal bond contributes to their psychological problems, and (iii) to explore the experiences of surrogates during and post-surrogacy. Fifty surrogates were compared with a matched group of 69 expectant mothers during pregnancy. Of these, 45 surrogates and 49 compairson group of mothers were followed up 4-6 months after the birth. All surrogates were hosting pregnancies for international intended parents and had at least one child of their own. Data were obtained using standardised questionnaires and in-depth interviews and were analysed using quantitative and qualitative methods. Indian surrogates were found to be more depressed than the comparison group of mothers, both during pregnancy and after the birth. However, giving up the newborn did not appear to add to surrogates’ levels of depression. There were no differences between the surrogates and the expectant mothers in anxiety or stress during either phase of the study. The examination of risk factors for psychological problems among the surrogates showed that anticipation of stigma, experiences of social humiliation and receiving insufficient support during pregnancy were associated with higher levels of depression following the birth. With respect to bonding with the unborn child, surrogates experienced lower levels of emotional bonding (e.g. they interacted less, and wondered less about, the foetus), but exhibited higher levels of instrumental bonding (e.g. they adopted better eating habits and avoided unhealthy practices during pregnancy), than women who were carrying their own babies. Contrary to concerns, greater bonding with the unborn child was not associated with increased psychological problems post-relinquishment. All surrogates were able to give up the child. Meeting the intended parents after the birth positively contributed towards surrogates’ satisfaction with relinquishment whereas meeting the baby did not. The qualitative findings on surrogates’ experiences showed that the majority lacked basic medical information regarding surrogacy pregnancy; hid surrogacy from most people; felt positive and supported at the surrogate house; lived in uncertainty regarding whether or not they would be allowed to meet the intended parents and the baby; and did not actually get to meet them. These findings have important implications for policy and practice on surrogacy in the Global South.
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Folovská, Kateřina. "Rekonstrukce kanalizace v Brně." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2012. http://www.nusl.cz/ntk/nusl-225488.
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The master thesis deals with the reconstruction of the sewerage in Brno-city, between the streets Roosveltova and Solniční. Due to the location of sewer in build-up area, the reconstruction will be performed by tunnelling technology – shield excavation. The thesis is mainly dedicate with design and structual design of sewer lining. The mathematical model is created in software Plaxis 8.2 2D.
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Caetano, Luciane Fonseca. "Estudo do comportamento da aderência em elementos de concreto armado submetidos à corrosão e elevadas temperaturas." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2008. http://hdl.handle.net/10183/18395.
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O estudo do comportamento de aderência tem recebido grande atenção desde o final da década de 40, entretanto muitas incertezas persistem no que tange à definição do melhor método de ensaio e do desempenho esperado ao longo da vida útil de uma estrutura, especialmente quando a mesma está exposta a condições ambientais desfavoráveis. A corrosão da armadura e a degradação térmica devida à exposição a altas temperaturas são exemplos de situações onde ocorrem importantes modificações nas propriedades dos materiais envolvidos, tendo forte impacto no desempenho da aderência. Tendo em vista que esta é uma propriedade de fundamental importância para a adequada transferência de esforços e compatibilização de deformações entre o concreto e o aço, colaborando para um bom desempenho global da estrutura, o estudo destes efeitos é vital. Este trabalho propõe a elaboração de um modelo matemático que represente o comportamento de aderência de peças submetidas à corrosão de armadura e à exposição a elevadas temperaturas. Além disto, busca realizar uma comparação entre os resultados obtidos por três métodos distintos de ensaios. Para a elaboração do modelo matemático foram produzidos cps de concreto com diferentes resistências à compressão, nos quais foram inseridas barras de aço de distintos diâmetros, para capturar a influência destas variáveis independentes. A modelagem estatística utilizou o modelo cubo-estrela, com definição de 5 níveis de referência para as variáveis temperaturas de exposição (ambiente, 200°C, 400°C, 600°C e 800°C), taxa de corrosão (0, 3, 6, 9 e 12% de perda de massa) e diâmetro da barra (8, 12.5, 16, 20 e 25 mm); e de 3 níveis para a resistência do concreto (25, 45 e 65 MPa). A determinação do comportamento de aderência foi executada através de duas técnicas de ensaio, selecionadas dentre as várias descritas na literatura: o ensaio de arrancamento simples (pull-out test), recomendado pela RILEM (1973), e o ensaio de arrancamento excêntrico (cantilever bond test), proposto por KEMP ET AL (1968). Ambas se caracterizam por serem ensaios de arrancamento, entretanto a primeira apresenta somente tensões de tração e de compressão e a segunda apresenta, além das tensões de tração e compressão, as de cisalhamento e de flexão, gerando uma situação mais próxima do que ocorre em estruturas reais. Para permitir a comparação entre métodos de ensaio com filosofias diferentes, mais uma técnica foi selecionada, o ensaio de viga (beam test), também recomendado pela RILEM (1973). De acordo com a análise dos resultados, o ensaio de arrancamento simples e de viga fornecem, respectivamente, valores de tensão de aderência, cerca de, 70% e 150% superiores aos obtidos em ensaios de arrancamento excêntrico. Os dados indicam, ainda, que os efeitos de deterioração são extremamente importantes para avaliação do desempenho final da aderência. Percebe-se que, para temperaturas mais baixas, até aproximadamente 300°C, a temperatura não provoca alteração no desempenho da aderência, mas, a partir de 550°C, a redução é superior a 50%, para concretos de resistências elevadas (acima de 50 MPa). Já a corrosão apresenta comportamento diferenciado, resultando em um acréscimo de cerca de 17%, da tensão de aderência para baixas taxas de perda de massa e posterior perda de desempenho com o aumento desta.<br>The study of the bonding mechanism in reinforced concrete elements has received attention from researchers since the forties. Nonetheless, there are still doubts regarding test methods and long term performance, especially when the structure is subjected to aggressive environmental conditions. Rebar corrosion and thermal degradation due to exposure to high temperatures are important examples of instances when significant changes in material properties take place, resulting in alterations of bonding performance. The study of these effects are vital, given that bonding is a fundamental property to ensure the adequate transfer of tensile stresses and strains between concrete and the steel rebar, which ensures good structural behavior. The proposed research aims to generate a mathematical model to explain the bonding behavior of structural RC elements subject to chloride corrosion and exposure to fire conditions. Besides, it seeks to compare results obtained using 3 distinct test methods for bonding evaluation. To this end, concrete specimens with different compressive strengths (25, 45 e 65 MPa) were produced, and bars of various diameters (8, 12.5, 16, 20 e 25 mm) were inserted in them. A statistical approach was adopted to reduce the experimental matrix, using the cube-star model, with 5 reference levels for the variables temperature of exposure (laboratory, 200°C, 400°C, 600°C e 800°C), corrosion rates (0, 3, 6, 9 e 12% weight loss) and bar diameter; and 3 levels for the variable concrete compressive strength, as discussed above. The bonding resistance was determined using two test methods selected from the various methodologies discussed in the literature: the RILEM pull-out test (1973) and the cantilever bond test, proposed by KEMP ET AL in 1968. Both evaluate bonding stresses, but the second one introduces shear and bending forces that create a stress distribution more close to the one found in real concrete beams. In order to improve the comparison between test methods, another technique was used in the second part of the work. The chosen technique was the beam test recommended by RILEM in 1973. According of the test results the pull-out test and the beam test result, respectively, in bonding values 70% e 150% higher than the ones registered in the cantilever bond test. The data obtained indicates, also, that the deterioration effects are extremely important to evaluate the bonding performance. For lower exposure temperature, up to around 300°C, the bonding behavior is not affected by the heat. But when the temperature exceeds 550°C, the bonding loss is higher than 50%, for the concretes with higher compressive strength (> 50 MPa). The deterioration by corrosion improves slightly the bonding resistance (up to 20%) when corrosion rates are lower than 1.5%. However, when corrosion increases, the bonding capacity decreases quite rapidly.
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Silvia, Cont. "New Voices in the Woods : A Study of Children’s Experience of the Forest as an Outdoor Educational Space." Thesis, Linköpings universitet, Institutionen för beteendevetenskap och lärande, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-149007.
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There is a growing body of literature that recognizes the importance of outdoor learning spaces in educational practice with children. However, previous studies of the outdoor learning spaces have omitted to address the young children’s perspectives on the outdoor environments that they experience as a part of the Forest School’s educational approach. Research on the subject has been mostly restricted to an adult perspective. Furthermore, the previously published studies are limited to Scandinavian countries and available in Scandinavian languages and, therefore, not easily accessible to an international audience. The aim of the present dissertation project is to explore young children’s (aged 3-6 years) voices on their experience, sense-making, and understanding of the educational space of a forest. A qualitative research paradigm was employed to explore the components that characterize children’s perception of the outdoor educational space. Ethnographic research methods (participants observation, informal conversation and material collection) were used to investigate children’s outdoor activities performed in two Italian preschools: a kindergarten outdoor oriented school and a Forest School. The collected materials (fieldnotes, interviews, and children’s drawings) were processed using a six-steps Thematic Analysis with the aim to gain a complex account of the data. The results indicate that the way children use, interact and, confer a meaning to their experience in the woods are represented by the following themes: Type of Place Attended, Nature Engagement, Relationship with the Woods, Responsibility and Risk, Imagination, Emotional Responses, Affordances, Relationships with Others, Discovery and Experimentation, Nature Education, Concerns for Nature, and Learnings Connected to the Curriculum.These results have provided a deeper insight on the children’s experience of the outdoor learning space of a forest. Moreover, the empirical findings in this study contributed to provide a new understanding of how children bond with the natural world and how they behave and experience it. Taking into account the exploratory nature of the present thesis, future research should further address the children’s perspectives on the outdoor education space, the forest. Furthermore, it would be interesting to investigate if the cognitive, emotional, and social resources and environmental attitudes developed by children in the forest as outdoor educational space are strictly intertwined with this particular environment or if they can be realized in more a conventional school setting.
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Bendzovski, Daniel. "Trend-sandwich : Exploring new ways of joining inspiration, such as different kinds of trends, through processes of morphing and melding different trendy garments and materials, for new methods, garment types, materials and expressions." Thesis, Högskolan i Borås, Akademin för textil, teknik och ekonomi, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-248.
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The aim of this work is to explore the joining of inspiration, such as different garments and materials, in relation to commonly used methods in the fashion industry when it comes to joining of different trends and references such as clashing and collaging. The work proposes a new method and framework for join- ing inspiration which generates different results depending on what kind of inspiration that is put in to it. A garment can roughly be broken down to a silhouette and shape, materials and details. The material put in to the method and framework is based on information from trend seminars for SS16, because that is how many of today’s trend-oriented fashion brands get there inspiration. Trendy garment silhouettes are mixed through processes of computational morphing in Adobe Flash by a generation of spin in the mixing process were shape hints are used in a new manner. The new generated silhouettes are further developed and materialized through procedures of interpretation and figuration. Different trendy materials are melded in a direct and concrete way through mixed media techniques such as laminating, fusing and vacuum-techniques. The final steps of the method is a garment shape and material synthesis with starting point in the generated shape with the final material. The projects intention is to let the physical experimentation, interpretation and figuration play a central role in the research process for new types of methods, garments, materials and expressive pos- sibilities.
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Lénat, Jean-François. "Structure et dynamique internes d'un volcan basaltique intraplaque oceanique : le piton de la fournaise (ile de la reunion)." Clermont-Ferrand 2, 1987. http://www.theses.fr/1987CLF2E394.
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Evolution de l'ile de la reunion, exemple de volcanisme intraplaque, plus particulierement du piton de la fournaise ou au cours des 500 000 dernieres annees, la tectonique d'effondrement a ete sub-continue et s'est manifestee par des caldeiras. Leur migration marque un deplacement des reservoirs dans l'edifice. Le glissement du grand brule semble sub-contemporain de la phase d'effondrement de l'enclos. L'activite recente est concentree sur le cone central a sa base et le long des rifts zones. Les transferts de magma entre les zones profondes et le reservoir superficiel ne sont pas continus. Les donnees de surveillance, depuis 1980 permettent de caracteriser les phenomenes precurseurs des eruptions et les mecanismes des intrusions et de la fracturation. Les consequences volcanotectoniques des deformations remanentes associees aux intrusions frequentes dans la zone centrale sont etudiees en terme de prevision et de l'evolution du volcan a moyen terme
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Slota, Phillip Michael Anton. "Evaluation of operational lake evaporation methods in a Canadian Shield landscape." 2013. http://hdl.handle.net/1993/22103.
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This thesis presents the findings of a study examining the hydrological processes controlling lake evaporation in a Canadian Shield landscape. The purpose of this study is to provide a recommendation on a suitable operational lake evaporation method for implementation in a partially-physically-based meso-scale hydrological model to improve simulation of the climate-hydrological feedback loop.
Detailed hydroclimatic observations were recorded for two lakes located in northwestern Ontario, Canada to estimate actual lake evaporation using a Bowen ratio energy balance approach. Multiple operational lake evaporation methods were evaluated for their ability to reproduce the reference lake evaporation rates. Each method was tested for its sensitivity to regionalized and estimated forcing data.
The results of this study found a modified version of the Priestley-Taylor combination method most accurately reproduced measured lake evaporation. This method incorporates a novel lumped lake heat storage model developed to estimate heat storage fluxes using re-gional climatic forcing.
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Muffler, Paul A. "Development of methods for low temperature diffusion bonding." Thesis, 1987. http://hdl.handle.net/10945/22747.
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Lin, Hung-Chi, and 林鴻基. "A Study on the Stablization of Excavation Faces for Shield Tunneling Methods." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/qhexed.
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碩士<br>國立臺北科技大學<br>土木與防災研究所<br>94<br>The project that the rapid transit system is gave impetus has at the technology and the experience makes great strides in recent years. This system has become one of tunnel technology which the engineering is familiar. In order to promote security of and the efficiency the shield tunneling construction, so the study collects the shield tunneling construction disaster case and type, as well as studies each kind of construction disaster occurrence reason and destruction mechanism.
These studies may provide the construction to take profit by observing others and can promote to receive business in the construction time vigilance and the disaster receives business strain ability; moreover, this study is built the type and the geological type relations which the shield tunneling construction destroys.
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Li, Chia-Wei, and 李佳薇. "Research on Optical Fiber and Metal Surface Bonding Methods." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/66696757845709785806.
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碩士<br>國立交通大學<br>土木工程系所<br>104<br>Fiber-optic sensing technology can be used to measure a variety of small changes in physical quantities, such as temperature, pressure, vibration, especially for the measurement of strain and temperature changes. The sensor made of Bragg fiber grating (FBG) is especially appealing because of its high sensitivity and dynamic range. When making an FBG sensor, it is imperative that the FBG is properly bonded to the surface of the metal substrate. In this study, a low-temperature glass paste was used as a bonding agent to attach optical fiber to the surface of stainless steel diaphragm. The diaphragm along with the attached FBG were used as a sensing element in FBG based sensors. The coating method, condition control and limitations of low-temperature glass adhesive bonding were developed in this research.
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Krantz, Bryan Andrew. "Protein folding : new methods unveil rate-limiting structures /." 2002. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:3060053.
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Tso, Wei-Jen, and 左惟仁. "A Study on Non-traditional Auxiliary Methods of Mirror Face Breaking for MRT Shield Tunnel." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/74452461917163304501.
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碩士<br>國立臺灣海洋大學<br>河海工程學系<br>98<br>TBM tunneling method is widely utilized in suburban areas for MRT systems both locally and abroad. But latent risks during launching and arriving of TBM, such as water or sand piping due to poorly controlled quality of the ground treatment works, are very challenging to the engineers.
For improve the ineffective and unsafe auxiliary traditional ground treatment methods, this paper will discuss the non-traditional ground treatment methods that are direct cutting method, bulk head chamber method, knock out panel filled with low-strength concrete method and knock out panel equipped with rubber tube method.
A review of the traditional Mirror Face construction method and its associated risks of disasters will be probed first. Subsequent to it come the four major construction methods which had been used by the Taipei MRT as well as the fourteen MRT projects of Kaohsiung City network. Besides the descriptions of principles and work flow of these construction methods, associated case of each will also be brought up for detailed examination.
Through comparison of the conditions of each application and their pros and cons in respect to construction characteristics, geological suitability, time and cost considerations, The "Direct Cutting" method is concluded as the best alternative in terms of time and construction safety. Though Bulk Head Chamber method also has its advantages, too long a preparation time is in no doubt its setback.
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Li, Yueh-Huan, and 李岳桓. "Using Taguchi Methods for Design Optimization of Silver Wire Bonding Process." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/34678423350829766392.
Full textAbstract:
碩士<br>國立中興大學<br>精密工程學系所<br>103<br>In recent years, silver alloy wire has been widely used in semiconductor industry. In contrast to conventional gold wire, silver alloy wire has better electrical property, thermal conductivity and lower cost.
In the study, choice of thermosonic wire bonders, silver alloy wire, ceramic capillary and copper alloy leadframe, in a clean room under conditions CLASS 1000, using the Taguchi method to find the four control factors affect the bonding process, bond power, bond force, bond time and bond temperature, with the L9(34) orthogonal array, study silver wire bonding process optimization design.
Wire bond the test sample, first using a microscope to check the standard appearance quality, then use the silver ball shear tester and silver wire pull tester to obtain experimental data, Taguchi method via signal to S/N ratio analysis of the optimal combination. Finally, although the value of the average shear ball down 10.5%, which is the standard deviation also decreased 40.8%, IMC increase of 12.8% is a key test results, cratering tested proved mass production of, Cpk increase of 12.8%. Although the value of the average wire pull down 1.4%, which is the standard deviation also decreased 18.1%, Cpk increase of 19.2%, up from B to A grade, experimental results show that there is a tendency to optimize the design.
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Wang, Chien-Pei, and 王建培. "Optimization of Copper Wire Bonding Process of ICs Package by Taguchi Methods." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/j9xutz.
Full textAbstract:
碩士<br>國立中興大學<br>電機工程學系所<br>106<br>In recent years, due to the acceleration of the price of gold, the rapid development of the IC (Integrated Circuit) package copper process has become the mainstream of the packaging industry. This research is aimed at the copper package process to improve the packaging quality to shorten the time, indirectly reduce costs for the company.
This paper uses the Taguchi Methods to find the four control factors that affect the wire bonding process, bond power, bond time, bond force, bond temperature, with the L9 (34) orthogonal array, substrate with PBGA (Plastic Ball Grid Array) product analysis and empirical research, with the most influential quality of wire bonding processes as the object of discussion, copper wire process parameters via the Signal to Noise Ratio (S/N ratio) optimization.
After repeated verification and comparison with the original operating parameters, the experimental results obtained that the average value of the ball bond copper ball increased by 12.75%, the standard deviation decreased by 20.39%, the CpK increased by 59.51%, the IMC test increased by 12.05%, and the yield increased by 1.08%. The average value of the stitch bond copper wire increased by 16.43%, the standard deviation decreased by 36.78%, the CpK increased by 96.89%, and the yield increased by 1.08%. Finally, the copper parameters were optimized for three reliability tests (HAST, TCT, HTSL). Both are better than the original parameters and no product failure mode occurs. Not only has the experimental time been shortened, but it has also helped improve the copper process capability, greatly improved product quality, and achieved important improvement contributions.
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Peng, Guan-Ying, and 彭冠穎. "Investigation of Non-destructive Methods to Evaluate the Bonding Strength in Corroded Rebar." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/ew28xx.
Full textAbstract:
碩士<br>中華大學<br>土木工程學系<br>106<br>Taiwan is located in an area where earthquakes frequently occur. In addition, being surrounded by ocean, Taiwan belongs to the subtropical island climate zone. This combination of factors leads to a highly corrosive environment for buildings in Taiwan, most of which are reinforced concrete structures. Steel corrosion is the primary cause of bond strength loss in structures, which would affect the safety and residual life of structures. Therefore, the academia has paid increasing attention to bond strength loss due to steel corrosion. In this study, nondestructive testing was conducted to examine stress damage to bond strength resulting from steel corrosion. The water–cement ratio of the two specimens used in this study was 0.7 and the dimensions of the specimens were 75 cm × 15 cm × 15 cm. The thickness of the concrete cover was 6 cm. One specimen contained #8 reinforcing bars and the other contained #10 reinforcing bars. A digital direct current power supply was employed to provide current to accelerate the corrosion process and cause minor, moderate, and severe corrosions in the specimens. Ground penetrating radars with a frequency of 1 GHz, high-energy ultrasonic testers, and corrosion-analyzing instruments were utilized to conduct bond strength tests to obtain the bond strength of reinforcing bars with varying degrees of corrosion and compare the interrelationships between reflected voltage, wave propagation time, corrosion potential, and bond strength.
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Lin, Kuan-Chung, and 林冠中. "Analysis of LED Wire Bonding Process Using Arbitrary Lagrangian-Eulerian and Explicit Time Integration Methods." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/37005900162611617804.
Full textAbstract:
碩士<br>國立清華大學<br>動力機械工程學系<br>101<br>In recent years, light emitting diode (LED), which has applied in outdoor illumination, automotive front lighting, and backlighting for large LCD display. It has become the key for the next generation illumination application. Wire bonding is one of the main processes used for connecting the signal of LED chip, it’s a multi-physic process including impact stage, ultrasonic vibration stage, and lift off stage. The failures of LED such as pad peeling, cracking, and delamination limit the development of LED and some are influenced by the wire bonding process. In a word, predicting and analyzing the failure of LED chip during wire bonding process is an important issue for decades, and this research will dedicate to constructing an effective simulation methodology on impact stage during wire bonding process.
In wire bonding system, the material property of free air ball (FAB) is much softer than that of the capillary, which compresses the FAB to land on pad. Thus, a large deformation phenomenon comes out on FAB during wire bonding process. Due to the large deformation problem, it’s easy to have element distortion issue on FAB while executing simulation work of wire bonding process. To avoid the divergent problem of finite element (FE) analysis, many researches reduce the compression distance of capillary on their contact simulation. Consequently, it is not easy to meet a good agreement with the real wire bonding process since the contact procedure of simulation is not completed. To solve the divergence problem, this research will construct FE models to discuss the element distortion issue using commercial software ANSYS®/LS-DYNA 3D with implicit and explicit method. Especially, an arbitrary lagrangian-eulerian (ALE) algorithm and the remesh concept will be proposed while utilizing the explicit method to solve the element distortion problem.
By utilizing the explicit method with 2nd level accuracy ALE algorithm, an effective simulation methodology is successfully achieved. Observing the ball height after impact stage, there’s only 0.5% discrepancy between this model and the real wire bonding sample, the geometry of bonded wire is also similar to the real one. It is concluded that the FE model established in this research not only conquer the element distortion problem, but proposed an effective methodology for simulating wire bonding process in the future as well.
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Chiu, Sang-Mao, and 邱桑茂. "Innovative Methods for Enabling Thermosonic Wire Bonding for Chips with Copper Interconnects：An Interfacial Phenomena Approach." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/54259525764899142757.
Full textAbstract:
碩士<br>國立中正大學<br>機械系<br>92<br>The miniaturization of electronic components causes the signal delay phenomenon to become increasingly pronounced, and hence limits the ability of these devices to satisfy the requirements of high frequency and high-speed transmission. An effective means of overcoming this problem is to utilize copper rather than aluminum as the interconnect material in integrated circuits, ultra-large-scale-integration devices, and other electronic components. Compared to aluminum, copper has a lower electrical resistivity and a higher electromigration resistance. However, unlike aluminum, copper is easily oxidized at high temperatures and fails to form a passivation oxide layer on its surface, which subsequently protects the sub-layers beneath from excess oxidization. This oxidization phenomenon creates significant problems in the wire bonding process of copper chips.
The current study presented two methods, innovative methods and metallic cap layer method, to overcome the bonding difficulty. Innovative methods include a specified range of cupric oxide film on the copper chip surface and the use of chemical method to yield a cuprous oxide surface film for enabling wire bonding. The metallic cap layers used are titanium and silver. The interfacial phenomenon is utilized to systematically obtain the operation parameters in the weldable range. Our results show that energy saturation phenomenon occurs in the bondable range. Within the weldable range, our experimental results indicate that current method and metallic cap layer allow for higher energy intensity than the argon shielding and thereby yield higher shear strength.
Another focus of this study is to measure circuit contact resistance under different metallic cap layer and oxide layer. A circuit contact resistance theory was established. Our findings show that, real contact area of bonding and surface layers are crucial to electronic resistance.
This study combines the theory of interfacial phenomena and innovative methods to overcome the obstacles in wire bonding for chips with copper interconnect. It constitutes a breakthrough in the wire bonding process for Cu chip.
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LYNH, DUONG HUYEN, and DUONG HUYEN LYNH. "The Study of Solvent-based Bonding Methods: Multiple Approaches to Fabricate Simple & Low-cost Thermoplastic Microfluidic Chips." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/f8qkm2.
Full textAbstract:
博士<br>國立臺灣科技大學<br>機械工程系<br>107<br>Since the advent of micro-gas chromatography in 1979, microfluidic technologies have been developing rapidly. The reason for this success is due to the unique chemical and physical features that occur in fluids at the micro/nano-size, which allowing for several advantages over conventional “macro”-techniques. Compared to the first materials used to fabricate microfluidic devices such as: silicon and glass, thermoplastics is becoming a popular choice with benefits including a wide range of material properties, low material costs, and compatibility with manufacturing methods which are scalable from laboratory prototyping to full scale mass production.
For the fabrication procedure of thermoplastic microfluidic chips, bonding is a critical step to produce the final enclosed fluidic paths. A variety of bonding methods for thermoplastic microfluidics have developed such as: adhesive bonding, thermal fusion bonding, solvent bonding, microwave welding, ultrasonic welding, and etc. Among these methods, solvent bonding has been proven as a rapid, highly effective, and high throughput method for the sealing of microchannels on thermoplastic substrates. The significant advantage of solvent bonding is possible to create a strong bond even at low temperatures with a minimum of equipment.
Based on the two actual needs: (1) addressing the lack of optical transparency required for tasks involving quantification of most existing 3D printed device, while the use of this technology in fabricating microfluidics is attracting considerable interest thanks to its low cost, rapid prototyping, and ability to realize complex structures; and (2) the highly attention to cyclic olefin copolymer (COC) material with high optical clarity into the deep-UV range, low water absorption, and exceptionally good resistance to a host of solvents including organics such as acetonitrile commonly used in liquid chromatography, a study of solvent-based bonding methods has developed to address the proposed needs through the bonding of (1) PMMA/PLA, PMMA/ABS; and (2) COC/COC substrates. To analysis the bonding quality, several experiments were conducted including: leakage test, burst test, cross-sectional investigation using microscopic, SEM, and the measurement of UV/VIS transmissivity. The experiment results clearly showed that the proposed bonding schemes successfully formed a strong bond between PMMA/PLA, PMMA/ABS, and COC/COC thermoplastic substrates, without sacrificing their intended functionalities.
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Wang, Chih-Sheng, and 王志聖. "Progress Study of the Pipe Jacking and Shield Tunneling Methods in Gravel Formation－A Case Study on Taichung Base Waste Water Outflow Pipeline Construction." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/12956630402351354418.
Full textAbstract:
碩士<br>朝陽科技大學<br>營建工程系碩士班<br>96<br>In order to enhance the quality of living and to meet government’s policy and worldwide trend, a lot of public constructions are being built during recent years. These constructions include telecommunications, electric power, water pipe, sewage pipe, household waste pipes and lifeline constructions. There are many on-going underground utilities have been built in Taichung. No-dig methods, such as pipe jacking and shield tunneling methods, have been used to replace open-cut excavations to avoid traffic impact and social cost. Methods used for underground constructions in gravel formation, however, are still under exploration due to lack of experience.
This objective of this study is to focus on investigation of Taichung base waste water outflow pipeline construction and to synthesize the construction cases and field data to compare with other references. Taichung base waste water outflow pipeline constructions are divided four sections. Collected data include the followings: Taichung base waste water outflow pipeline construction status, geology, boring logs, granular size and distribution of gravel formation, overburden depth, pipe jacking and shield machine(structure of machine body and cutting face), attrition and repair of shield machine, shield tunnel (rotational force and jacking force ), pulling out speed, soil emission, encountered problems, solution used to overcome problems, ground surface settlement and impact, raise or slip of ground in process of construction, length of excavation and jacking, jacking installation and jacking force, condition and effect of underground water, and effect of unlined construction.
Gravel formations are the most common formation in Taichung area in Taiwan, most of the gravels are hard and having high strength and strong interlock between gravels. Thus, it is difficult to cut using any machine. Those machines will be easily worn and torn seriously, especially the cutting face for the pipe jacking and shield tunneling methods, in the gravel formation. The results show that the jacking force, torque of cutting face, and pressure of screw machine during tunnel excavation will interact with each others. As the torque increases, then the excavation speed and thrust may decrease. In order to increase the volume of excavation, the pressure inside the screw and the rotation speed should be lower down and increased, respectively. The cutting disks inside the cutting face should be replaced after certain tunneling length, and the actual length is shorter than the expected. Monitoring results from the ground settlements and inclinometers show that only small changes are recorded and they are within the tolerance range.
In addition, this research results are compared with the previous data. These data are all synthesized, analyzed and compared. Results obtained from the studies could be used for construction and design in gravel formation in the future.
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Kim, Samuel. "Novel Methods in Ball Bond Reliability Using In-Situ Sensing and On-Chip Microheaters." Thesis, 2012. http://hdl.handle.net/10012/7217.
Full textAbstract:
Wire bonding is the process of creating interconnects between the circuitry on a microchip and PCB boards or substrates so that the microchip can interact with the outside world. The materials and techniques used in this bonding process can cause a wide variation in bond quality, so wire bond reliability testing is very important in determining the quality and longevity of wire bonds. Due to the fact that microchips are encased in protective resins after bonding and their substrates attached to the larger device as a whole, once any single wire bond fails then it could jeapordize the entire device as the wire bonds cannot be individually replaced or fixed. Current methods of reliability testing are lengthy and often destroy the entire sample in the process of evaluation, so the availability of novel non-destructive, real-time monitoring methods as well as accelerated aging could reduce costs and provide realistically timed tests of novel wire bond materials which do not form Intermetallic compounds (IMCs) as rapidly as Au wire on Al substrates.
In this thesis, five new chip designs for use in wire bond reliability testing are reported, focusing on the first joint made in a wire bond, called the ball bond. These chips are scaled either to test up to 55 test bonds simultaneously or just one at a time, introducing different requirements for microchip infrastructure capabilities, such as on-chip sensing/data bus, multiplexer, and switches able to operate under High Temperature Storage (HTS) which ranges from temperatures of 150-220 ??C. There are different heating requirements for each of these microchips, needing to be heated externally or containing on-chip microheaters to heat only the ball bond under test, and not the rest of the microchip or surrounding I/O pads. Of the five chip designs, sample chips were produced by an external company. Experimental studies were then carried out with two of these chip designs. They were specifically made to test novel methods of determining ball bond reliability using in-situ, non-destructive sensing, in real-time, while the ball bond undergoes thermal aging.
Pad resistance as an analysis tool for ball bond reliability is proposed in this thesis as a new way of evaluating ball bond quality and allows for the testing of electrical connection without the need for specialized measurement probes or difficult bonding processes that contact resistance measurements require. Results are reported for pad resistance measurements of a ball bond under very high temperature storage (VHTS) at 250 ??C, a temperature exceeding typical HTS ranges to accelerate aging. Pad resistance measurements are taken using the four-wire measurement method from each corner of the bond pad, while reversing current direction every measurement to remove thermo-electric effects, and then calculating the average square resistance of the pad from this value.
The test ball bond is aged using a novel on-chip microheater which is a N+ doped Si resistive heater located directly underneath the bond pad, and can achieve temperatures up to 300 ??C while not aging any of the I/O pads surrounding it, which are located ~180 ??m away. A 50 ??? resistor is placed 60 ??m away from the heater to monitor the temperature. The use of a microheater allows the aging of novel wire types at temperatures much higher than those permitted for microchip operation while thermally isolating the test bond from the sensing and power bonds, which do not need to be aged. Higher temperatures allow the aging process to be sped up considerably. The microheater is programmatically cycled between 250 ??C (for 45 min) and 25 ??C (for 15 min) for up to 200 h or until the pad resistance measurements fail due breakdown of the bonding pad. Intermetallic compounds forming between the ball bond and the pad first become visible after a few hours, and then the pad becomes almost completely consumed after a day. The pad resistance is measured every few seconds while the sample is at room temperature, and the increase in pad resistance agrees with the fact that Au/Al IMC products are known to have much higher resistance than both pure Au or Al.
Also discussed are some aging results of Au wires and Pd coated Cu (PCC) wires bonded to Al bonding pads and aged at a temperature of 200 ??C in an oven for 670 h. The oven aged Au ball bonds also saw IMC formation on the surface of the bonding pad, much like the microheater tests. The PCC ball bonds became heavily oxidized due to lack of Pd on the surface of the ball, the wire portions did not oxidize much.
In conclusion, the new structures have been demonstrated to age ball bonds faster than with conventional methods while obtaining non-destructive data. Specifically, the new microheater ages a test bond at an accelerated rate without having an observable effect on the I/O connections used to monitor the test bond. Pad resistance measurements correlate to the aging of the test bond and ensure the electrical integrity of the joint is checked.
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Ching-Hsun, Chi, and 紀景薰. "The Research on the Effects of Plate Bonding Methods on the Corrosion of the Reinforcement in Concrete Contaminated with Chloride ion." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/50834605922512266694.
Full textAbstract:
碩士<br>中華大學<br>建築與都市計畫學系碩士班<br>87<br>ABSTRACT
The contamination of chloride ion in reinforced concrete with poor concrete quality, can cause the reinforced steel of concrete corrode easily. The corrosion of reinforced steel is a major cause of structure failure of reinforced concrete. This study elaborates that the reinforced concrete samples with different concrete strengths cover depths, different chloride ion contents, bonded with steel and FRP plates and were utilized to measure the change of corrosion rate of reinforced steel due to the plate bonding method by using AC Impedance method. It is aimed to study effect the plate bonding on the corrosion rate of reinforced steel under different cover depths, chloride ion contents and plate bonding materials.
The results of this study are as follows:
1. In the range of chloride contents studied, the corrosion rate of reinforced steel is reduced by 0.03μA/㎝2～0.27μA/㎝2 indicating that the supply of water and oxygen decrease after the samples are plate bonded.
2. At chloride ion content below 1.82 kg/m3, the corrosion rate is not high and between 0.05 μA/㎝2 and0.5μA/㎝2 before samples were plate bond. Therefore, the effect of the plate bonding on the corrosion rate of reinforcement is significant.
3. When chloride ion content reach 5.46 kg/m3, the reinforced steel corroded very seriously. The corrosion rate are between 1.71μA/㎝2 and 2.84μA/㎝2. Since the concrete contaminated with chloride ion has tendency to absorb humidity and to reduce concrete's electrical resistance. Thus the corrosion rate of reinforced steel reduce slightly after the bonding of steel and FRP plates.
4. Water cement ratio affects the porosity of concrete, consequently affects the vaporization of water in concrete and the ability to absorb humidity in concrete. Therefore, it has a profound effect on the corrosion of reinforced concrete when concrete is bonded with steel and FRP plates.
5. When the concrete bonded with steel and FRP plates, the electrical resistance of concrete increase for both cases. This indicates that above two materials have the same effects on reducing the penetration of water and oxygen into concrete.
6. The depth of cover affects the water content at the concrete surrounding the reinforced steel. In this study, the relative humidity of test environment is comparative low. Therefore, when the depth of cover is thin, the water content at the concrete surrounding the reinforced steel vaporizes easily. Consequently, the water content is low after it was bonded with plates and the electrical resistance of concrete increases, and resulting in the decrease of the corrosion rate of the reinforced steel. On the contrary, when depth of cover is larger, the residual water content is high, and the corrosion rate will not decrease easily. But in actual environment, humidity can be higher than that of test environment, therefore, after plate bonding the electrical resistance of concrete will not increase easily, the corrosion rate of the reinforced steel will not decrease easily when the depth of cover is small.
7. The effect of the plate bonding on the reduction of the corrosion rate is around 0.2 μA/㎝2. The feasibility of plate bonding on corrosion protection of the reinforcement in concrete is determined by the corrosion rate before the plate bonding. The higher corrosion rate before the plate bonding the lower effect of the plate bonding. For example, if corrosion rate is above 1μA/㎝2, the effect of the plate bonding is below 20%.Therefore ,to assess the feasibility of using the plate bonding method to protect the reinforcement ,one must inspect the corrosion rate of the reinforced steel ,and utilize it as the reference base for evaluation of the effectiveness of using the plate bonding methods.
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Chang, Nathan, and 張華基. "Application of Taguchi Methods to Improve the Semi-conductor Packaging Process - A Case Study for Wire Strength Optimization of Wire Bonding Process." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/19348131731722772210.
Full textAbstract:
碩士<br>國立交通大學<br>工業工程與管理學程碩士班<br>90<br>The main purpose of semi-conductor packaging process is to ensure workable functionality and protect IC (Integrated Circuit) chip by connecting the electrical circuits of IC chip with external lead frame and injecting the molding compound. In packaging process, the operation of wire bonding is to link the internal/external electrical circuits between IC chip and lead frame. The bonding wire is possibly be broken or damaged during the following molding process if the wire strength is not strong enough. Furthermore, this defect will cause reliability concern in back-end PCB assembly process. Such defect of weak wire strength is not only damaged the quality image of packaging manufacturer, but also customers raised claim on this defect sometimes. Moreover, the afterward business orders will be deducted or cancelled.
The firm applied Taguchi’s approach to the wire bonding process, so as to improve the wire strength in short time. The quality characteristic was decided as reading value by “Wire Pull Test”. The study was also analyzed along with appropriate orthogonal arrays to accelerate and simplify the process of experiment. Based on Larger-The-Better, Signal-to-Noise ratio (SN ratio) data to analyze, the result shows the method result in the optimal parameter design. Furthermore, the additive model is appropriate in the experiment by means of confirmation experiment. The proposed optimal conditions do improve the wire strength of wire bonding process.
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Patel, Dhara. "Influence of saliva contamination on resin bond durability to zirconia - Effect of cleaning methods." Thesis, 2015. http://hdl.handle.net/1805/7293.
Full textAbstract:
Indiana University-Purdue University Indianapolis (IUPUI)<br>Background and Rationale: As compared with glass-based ceramics, zirconia has gained considerable popularity in restorative dentistry due to its superior mechanical properties. Clinically, however, zirconia ceramics pose a significant challenge regarding the achievement of a reliable and durable bond to resin-based cements. Thus far, it has been established that zirconia bond to resin-based cements can be enhanced after different surface conditioning methods, such as airborne particle abrasion with aluminum oxide particles. Meanwhile, another major issue pertaining to bonding of ceramic restorations is related to its potential contamination before cementation. Briefly, after sandblasting and clinical try-in procedures, zirconia can be contaminated with saliva and/or blood. As with many metals, zirconium shows a strong affinity towards the phosphate group found in saliva and other fluids, which reacts with the zirconia surface and makes bonding very difficult. Recently, a new cleaning agent called Ivoclean® (Ivoclar-Vivadent), which is an alkaline suspension of zirconium oxide particles, has been introduced in the market to remove contamination from zirconia in an effort to improve bonding to resin cements.
Objective: The purpose of this study was to evaluate the influence of saliva contamination and the effect of several cleaning methods, including Ivoclean on resin bond strength to zirconia. Materials and Methods: Eighty square-shaped specimens (ϕ = 12 mm x 12 mm x 3 mm) of yttria-stabilized full-contour zirconia (Diazir®, Ivoclar-Vivadent, Amherst, NY) were sectioned from zirconia blocks using a water-cooled diamond blade. Then, these specimens were embedded in acrylic resin, and their surfaces gradually finished with silicon carbide papers (600 grit to 1200 grit). The prepared zirconia surfaces were sandblasted with 50-μm aluminum oxide particles for 15 s, under 2.5 bars and from distance of 10 mm. After sandblasting the specimens were cleaned in an ultrasonic bath containing distilled water for 5 min and air-dried for 10s. All samples were equally divided into 4 groups (n = 20) according to the cleaning method. Airborne particle abraded specimens without contamination was served as the control group. Remaining groups were contaminated with saliva, and subjected to different cleaning protocols, namely: Ivoclean®, 70% isopropanol, and no treatment. Two resin cement buttons (Multilink – Ivoclar-Vivadent, Amherst, NY) were built over each zirconia surface and light-cured following the manufacturer recommendations. The influence of contamination and surface cleaning methods on ceramic bond durability were examined after 24 h on half of the samples in each group (n = 10, n = 20), and the other half (n = 10, n = 20) specimens will undergo 6000 thermocycles (TC) before shear bond testing in the universal testing machine.
Conclusion of Expected Outcomes: The shear bond strength of resin cement to zirconia led to a significant improvement after cleaning with Ivoclean both immediately and after thermal aging.
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Alkatheeri, Mohammed Saeed 1981. "Effect of halloysite aluminosilicate clay nanotube incorporation into bonding agents on shear bond strength to human dentin." Thesis, 2013. http://hdl.handle.net/1805/3870.
Full textAbstract:
Indiana University-Purdue University Indianapolis (IUPUI)<br>In adhesive dentistry, obtaining a good bond is a fundamental goal. It has been suggested that filler addition to the adhesives would increase the bonding strength of the adhesive layer. Halloysite aluminosilicate nanotubes (HNTs) are biocompatible, hydrophilic, durable, and have high mechanical strength. These advantages make them good candidates to be used as reinforcing agents for improving the properties of dental adhesives.
The objective of this study was to evaluate the effect of incorporating HNTs into a commercial two-step etch-and-rinse adhesive system or one-step self-etch adhesive system on dentin shear bond strength.
HNTs were incorporated into the two commercial adhesive systems in 0 wt%, 5 wt%, 10 wt%, and 20 wt%. The commercial control adhesives and the experimental adhesives were used to bond occlusal dentin of 120 extracted human molar teeth and then tested for shear bond strength by a universal testing machine with a semi-circular edge at a crosshead speed of 1.0 mm/min. Debonded specimens were examined under light microscopy to evaluate the fracture pattern. Resin-dentin interface were evaluated under scanning electron microscopy (SEM) after bonding dentin slabs using commercial control adhesives and experimental adhesive that showed numerically highest shear bond strength from each adhesive system. Two-way ANOVA was used to evaluate the effects of adhesive system and nanofiller content on shear bond strength. Pair-wise comparisons between groups were made using Fisher's (LSD) (p < 0.05).
For the self-etch adhesive system, only incorporation of 5 wt% showed a significant increase in shear bond strength to dentin compared with the commercial control group. For the etch-and-rinse adhesive system, there was no significant difference in shear bond strength between HNTs filled adhesives groups and the commercial control group. Resin-dentin interface SEM evaluation showed nanotubes infiltrated into dentinal tubules.
In conclusion, incorporating the self-etch adhesive system with 5 wt% HNTs increased the bond strength to dentin. Incorporation of up to 10 wt% filler concentration into both the self-etch and the etch-and-rinse adhesive systems did not adversely affect the bond strength to dentin or the handling properties. HNTs can penetrate along with resin tags into dentinal tubules, which could expand the use of their unique properties.
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Kotke, Mike [Verfasser]. "Hydrogen-bonding (thio)urea organocatalysts in organic synthesis : state of the art and practical methods for acetalization, tetrahydropyranylation, and cooperative epoxide alcoholysis / vorgelegt von Mike Kotke." 2009. http://d-nb.info/1009535994/34.
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Rajitrangson, Phitakphong 1982. "Effect of surface conditioning methods on repair bond strength of microhybrid resin matrix composite." Thesis, 2010. http://hdl.handle.net/1805/2138.
Full textAbstract:
Indiana University-Purdue University Indianapolis (IUPUI)<br>Repair is an alternative treatment option in many cases to replacement of resin matrix composite restoration. However, aged resin matrix composites have a limited number of carbon-carbon double bonds to adhere to a new layer of rein. Therefore, surface treatments of the aged resin matrix composite surface prior to repairing could improve the repair bond strength.
The objectives of this study were to: 1) To evaluate various surface treatments on
shear bond strength of repair between aged and new microhybrid resin matrix composite, and 2) To assess the influence of applying a silane coupling agent after surface
treatments.
Eighty disk-shaped resin matrix composite specimens were fabricated and
thermocycled 5000 times prior to surface treatment. Specimens were randomly assigned to one of the three surface treatments (n = 20): 1) Airborne abrasion with 50 μm aluminum oxide, 2) Tribochemical silica coating (CoJet), or 3) Er,Cr:YSGG laser and control group (n = 20). Specimens were cleaned with 35-percent phosphoric acid, rinsed, and dried. Each group was assigned into two subgroups (n =10): a) no silanization, and b) with silanization. Adhesive agent was applied and new resin matrix composite was bonded to each conditioned surface. Bond strength was evaluated by shear test. Data were analyzed with a two-way ANOVA model. The interaction between conditioning and silanization was significant(p = 0.0163), indicating that comparisons of silanization must be evaluated for each conditioning method, and that comparisons of conditioning methods must be evaluated separately with and without silanization. Airborne particle abrasion showed significantly
higher repair bond strength than Er,Cr:YSGG laser without silanization (p < 0.0001) and with silanization(p = 0.0002), and higher repair bond strength than the control without silanization (p < 0.00001) and with silanization (p < 0.00001). Airborne particle abrasion
did not have significantly different in repair bond strength than Tribosilica coating without silanization (p = 0.70) or with silanization (p = 0.33). Tribosilica coating had significantly higher repair bond strength than Er,CR:YSGG laser without silanization
(p < 0.0001) and with silanization (p < 0.0001), and significantly higher repair bond strength than control without silanization (p < 0.0001), but not with silanization (p =0.16). Er,CR:YSGG laser and control did not have significantly different repair bond strength without silanization (p = 1.00) or with silanization (p = 0.11). There was no
effect of silanization on repair bond strength overall (p = 0.34) for any of the surface conditioning methods (p = 0.76 for airborne particle abrasion; p = 0.39 for tribosilica coating; p = 1.00 for Er,Cr:YSGG laser, or p = 0.39 for control). Airborne particle abrasion with 50-μm aluminum oxide particle and tribochemical silica coating followed by the application of bonding agent provided the highest shear bond strength values, suggesting that they might be adequate methods to improve the quality of the repairs of resin-matrix composites.
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Bourlon, Évelise. "Analysis of gravity and magnetic fields in the Canadian Shield using standard and wavelet-based methods = Analyse des champs de gravité et magnétique dans le Bouclier canadien à l'aide de méthodes traditionnelles et basées sur la transformée en ondelettes." Thèse, 2004. http://constellation.uqac.ca/699/1/18040901.pdf.
Full textAbstract:
Cette thèse présente une étude géophysique du Bouclier canadien à l'aide de données gravimétriques et magnétiques. La première partie concerne les méthodes utilisées. Les outils classiques sont introduits ainsi que des méthodes de traitement de données à l'aide de la transformée en ondelettes. Une méthode de caractérisation des sources responsables des anomalies du champ est exposée ainsi qu'une méthode de calcul de l'épaisseur élastique de la lithosphère. La seconde partie de la thèse concerne les applications.
L'étude du prolongement des structures géologiques Protérozoïques de l'orogène Trans-Hudson et Archéennes de la province du Supérieur sous le couvert sédimentaire du bassin de Williston fait l'objet d'un chapitre. Nous avons produit des cartes des champs gravimétrique et magnétique afin d'effectuer une interprétation visuelle des structures géologiques. Les détails ont été rehaussés à l'aide de dérivées horizontales des champs. Nous avons étudié les champs à différentes échelles grâce à la transformée en ondellettes. Une carte de la profondeur du socle magnétique a été produite en utilisant la déconvolution d'Euler. Grâce à cette étude, nous avons montré que certaines structures géologiques qui composent l'orogène transhudonien dans le nord du Manitoba et du Saskatchewan se prolongent au moins jusqu'à la frontière américaine et que les sous-provinces du Supérieur se prolongent vers l'ouest sous les sédiments dans le Manitoba. Nous nous sommes intéressé à deux structures tectoniques: une zone de contact entre deux provinces géologiques et une faille majeure. Nous avons déterminé leurs positions et avons caractérisé leurs extensions verticales et leurs pendages.
Le chapitre suivant traite du calcul de l'épaisseur élastique dans l'est du Bouclier canadien. Nous avons calculé cette épaisseur avec une méthode traditionnelle. Nous avons montré que la lithosphère au Québec et au Labrador est très rigide. Nous avons développé une méthode utilisant la transformée en ondellettes afin d'étudier l'anisotropie de ce paramètre. Cette méthode a montré que la rigidité est très anisotrope dans la province du Supérieur et beaucoup plus isotrope dans la province de Grenville.
Dans le dernier chapitre, nous présentons l'étude des champs de gravité et magnétique dans la Baie d'Ungava. Ce travail s'inscrit dans le cadre du programme LITHOPROBE ECSOOT (Eastern Canadian Shield Onshore-Offshore Transect). Nous avons établi des cartes de champs de potentiel en compilant des données de différentes origines: données de terrain et satellitaires pour le champ gravimétrique, données aéroportées et marines pour le champ magnétique. L'interprétation de ces cartes nous a permit de conclure qu'une petite partie de la province du Supérieur se trouvait à l'est de l'orogène du Nouveau-Québec au Labrador et que certaines structures géologiques présentes au Labrador traversent la Baie d'Ungava jusqu'à la Terre de Baffin. Ce chapitre a fait l'objet d'un article publié dans le volume de synthèse du projet ECSOOT dans le Journal Canadien des Sciences de la Terre.
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"The role of therapy dog in facilitating social interaction for autistic children: an experimental study on animal-assisted play therapy." Thesis, 2011. http://library.cuhk.edu.hk/record=b6075483.
Full textAbstract:
Fung, Suk Chun.<br>Thesis (Ed.D.)--Chinese University of Hong Kong, 2011.<br>Includes bibliographical references (leaves 328-337).<br>Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.<br>Abstract also in Chinese.