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Mjörnman, Jesper, and Daniel Mastell. "Randomness as a Cause of Test Flakiness." Thesis, Linköpings universitet, Institutionen för datavetenskap, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-177303.
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With today’s focus on Continuous Integration, test cases are used to ensure the software’s reliability when integrating and developing code. Test cases that behave in an undeterministic manner are known as flaky tests, which threatens the software’s reliability. Because of flaky test’s undeterministic nature, they can be troublesome to detect and correct. This is causing companies to spend great amount of resources on flaky tests since they can reduce the quality of their products and services. The aim of this thesis was to develop a usable tool that can automatically detect flakiness in the Randomness category. This was done by initially locating and rerunning flaky tests found in public Git repositories. By scanning the resulting pytest logs from the tests that manifested flaky behaviour, noting indicators of how flakiness manifests in the Randomness category. From these findings we determined tracing to be a viable option of detecting Randomness as a cause of flakiness. The findings were implemented into our proposed tool FlakyReporter, which reruns flaky tests to determine if they pertain to the Randomness category. Our FlakyReporter tool was found to accurately categorise flaky tests into the Randomness category when tested against 25 different flaky tests. This indicates the viability of utilizing tracing as a method of categorizing flakiness.
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Nilsson, Joel. "Possibilities of automatic detection of "Async Wait" Flaky tests in Python applications." Thesis, Linköpings universitet, Institutionen för datavetenskap, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-177329.
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Flaky tests are defined as tests that show non-deterministic outcomes, meaning they can show both passing and failing results without changes to the code. These tests cause a major problem in the software development process since it can be difficult to know if the cause of a failure originates from the production- or test code. Developers may choose to ignore failing tests known to be flaky when they might actually hide real bugs in the production code. This thesis investigates a specific category of flaky tests known as "Async Wait", which are tests that makes asynchronous calls to servers and other remote resources and fails to properly wait for the results to be returned. There are tools available for detecting flaky tests, but most of these need the test to be executed and operate on run time information. In order to detect potential flakiness in an even earlier state, this thesis looks in to if it is possible to predict flaky outcomes by analyzing only at the test code itself without running it. The scope is limited to the Async Wait only to determine in which cases and under what circumstances developing an algorithm to automatically detect these flaky tests would be possible in this category. Commits from open source projects on GitHub were scanned for Async Wait flaky tests with the intention of finding the characteristics of the asynchronous calls and how the waiting for them is handled as well as how the flakiness is resolved by developers in practice in order to see if the information in only the test code is enough to predict flaky behavior.
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Moniaga, Catharina Sagita. "Flaky Tail Mouse Denotes Human Atopic Dermatitis in the Steady State and by Topical Application with Dermatophagoides pteronyssinus Extract." Kyoto University, 2013. http://hdl.handle.net/2433/174757.
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Kanneganti, Joshika, and Krithi Sameera Vadrevu. "Eliminating effects of Flakiness in Embedded Software Testing : An industrial case study." Thesis, Blekinge Tekniska Högskola, Institutionen för programvaruteknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-19391.
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Background. Unstable and unpredictable tests, herein referred to as flaky tests, pose a serious challenge to systems in the production environment. If a device is not tested thoroughly, it will be sent back for retesting from the production centers, which is an expensive affair. Removing flaky tests involves detecting the flaky tests, finding the causes of flakiness and finally the elimination of flakiness. The existing literature provides information on causes and elimination techniques of flakiness for software systems. All of these are studied thoroughly, and support is taken from interviews to understand they are applicable in the context of embedded systems. Objectives. The primary objective is to identify causes of flakiness in a device under test and also techniques for eliminating flakiness. Methods. In this paper, we applied a literature review to find the current state-of-art of flakiness. A case study is selected to address the objectives of the study. Interviews and observations carried out to collect data. Data analysis performed using a directed content analysis method. Results. Observations resulted in eliminating 4 causes of flakiness in embedded systems. Interview results in finding 4 elimination techniques which were not found in the literature. Conclusions. Causes and Elimination techniques for the domain of embedded systems are identified. Knowledge translation between the domains was carried out effectively.
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James, J. D. "New production routes for manufacture of flake powders." Thesis, Swansea University, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.637396.
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A study has been made of the characteristics of flake brass powders, and a route has been developed to produce such powders by small scale vibratory batch milling. Brass flakes are used as pigments for producing a 'gold leaf' appearance in ink and paints, and there are a variety of other applications. The commercial production route involves the slow process of rotary ball milling a coarse feed powder on a continuous basis. Initially a range of industrially produced powders were examined by a variety of techniques to determine the relationship between powder characteristics and commercial quality. Numerical calculations were carried out for the elastic deformation of balls on impact and the resulting plastic deformation of powder to flakes during ball milling. Vibratory ball milling of brass powder to flakes was then undertaken in the laboratory. The principal variables investigated were: milling time, ball size, initial particle size, total weight of powder and quantity of additive employed. The effect of these variables on flake production is described in terms of the processes of microforging, fracture and agglomeration. It was found that, providing one starts with a fine powder, vibratory milling could produce flakes similar to the industrial product much more rapidly than rotary ball milling. Vibratory milling is thus an excellent method for rapid production of small quantities of brass flakes.
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Gaspari, Federica. "Il dibattito sull'essenza della matematica. Scienza della natura o libera invenzione della mente umana?" Master's thesis, Alma Mater Studiorum - Università di Bologna, 2011. http://amslaurea.unibo.it/1822/.
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Questa dissertazione si concentra sul dibattito circa l’essenza della matematica a partire dalla nascita delle geometrie non euclidee. Essa è una scienza della natura o una costruzione (e dunque una libera invenzione) della mente umana?
Trattando altresì della crisi dei fondamenti, e tenendo a mente le posizioni platoniste e costruttiviste, questa tesi analizza le risposte che, da fine Ottocento in poi, diedero Jules-Henri Poincaré, Bertrand Russell, L.E.J. Brouwer e David Hilbert, e con loro le varie correnti convenzionaliste, logiciste, intuizioniste e formaliste.
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Agarwal, Neetu. "Technology of large flake acheulean at lalitpur, central india." Doctoral thesis, Universitat Rovira i Virgili, 2014. http://hdl.handle.net/10803/306132.
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Aquesta tesi es proposa d’estudiar l’Aixelià a Lalitpur, Índia Central, sota l’òptica del context del jaciment, el procés de formació del jaciment i l’organització tecnològica duta a terme pels hominins. Pretén comprendre els trets característics de l’organització tecnològica aixeliana al jaciment de Lalitpur. S’ha dut a terme mitjançant l’anàlisi del conjunt complet recuperat en el jaciment i no només focalitzant-la en els bifaços com a “fòssil tipus” de l’Aixelià com s’ha fet tradicionalment. En aquest sentit, s’ha emprat l’aproximació pròpia de l’anàlisi de la cadena operativa per comprendre l’organització tecnològica completa des de l’obtenció de la matèria primera, a la reducció dels nuclis, la producció de les ascles, llur modificació en eines configurades, l’ús, el reavivat, el seu abandonament i l’alteració en el decurs de processos post-deposicionals. També s’han tingut en compte atributs quantitatius per permetre les comparacions amb altres conjunts.
Com que el conjunt va ser recuperat en contextos pròxims a la superfície, s’han emprès també estudis detallats del context del jaciment i dels processos de la seva formació a fi de confirmar la integritat del conjunt.
El tipus de matèria primera ha estat sovint considerat com un factor important que afecta les eines de pedra, sobretot des del moment en què el conjunt està manufacturat principalment en granit. Per aquesta raó, s’han dut a terme estudis detallats de la matèria primera.
Per acabar l’Aixelià de Lalitpur ha estat comparat amb d’altres conjunts ben estudiats de l’Índia, Àfrica i Europa a fi de situar l’Aixelià indi en un context global.
L’estudi de l’organització tecnològica dels hominins aixelians de Lalitpur ha servit per a deduir-ne una imatge entenedora de la variabilitat tecnològica de les eines de pedra dels hominins aixelians. Ha ajudat en una redefinició de l’Aixelià de l’Índia i en la seva situació en un context global. A més ha servit per clarificar el concepte de “Aixelià de Grans Ascles” i les implicacions comportamentals d’aquesta tecnologia.
També ha destacat la importància dels jaciments “de superfície” en l’estudi del Paleolític inferior, especialment a l’Índia i ha mostrat la importància dels estudis de la formació dels jaciments en la comprensió de les característiques dels jaciments paleolítics.Esta tesis se propone el estudio del Achelense de Lalitpur, India Central, bajo la óptica del contexto del yacimiento, el proceso de formación del mismo y la organización tecnológica llevada a cabo por los homininos. Pretende comprender los rasgos característicos de la organización tecnológica achelense en el yacimiento de Lalitpur. Se ha llevado a cabo mediante el análisis del conjunto completo recuperado en el yacimiento y no tan sólo focalizándolo en los bifaces como “fósil tipo” del Achelense, tal como se había hecho tradicionalmente. En este sentido, se ha empleado la aproximación propia del análisis de la cadena operativa para comprender la organización tecnológica completa desde la obtención de la materia prima, a la reducción de los núcleos, la producción de lascas, su modificación en herramientas configuradas, su uso, el reavivado, su abandono y la alteración a lo largo de procesos post-deposicionales. También se han tenido en cuenta atributos cuantitativos para permitir las comparaciones con otros conjuntos. Como el conjunto fue recuperado en contextos próximos a la superficie, se han emprendido también estudios detallados del contexto del yacimiento y de los procesos de su formación a fin de confirmar la integridad del conjunto. El tipo de materia prima ha sido a menudo considerado como un factor importante que condiciona las herramientas de piedra, sobre todo desde el momento en que el conjunto está manufacturado principalmente en granito. Por esta razón, se han llevado a cabo estudios detallados de la materia prima. Para terminar el Achelense de Lalitpur ha sido comparado con otros conjuntos bien estudiados de la India, África y Europa con el fin de situar el Achelense indio en un contexto global. El estudio de la organización tecnológica de los homininos achelenses de Lalitpur ha servido para deducir una imagen clara de la variabilidad tecnológica de las herramientas líticas de los homininos achelenses. Ha ayudado a la redefinición del Achelense de la India y en su situación en un contexto global. Además ha servido para clarificar el concepto de “Achelense de Grandes Lascas” y las implicaciones comportamentales de esta tecnología. También ha destacado la importancia de yacimientos de “superficie” en el estudio del Paleolítico inferior, especialmente en la India y ha mostrado la importancia de los estudios de la formación del yacimiento en la comprensión de la naturaleza de los yacimientos paleolíticos.
The present thesis attempts to study the Acheulean at Lalitpur, Central India in terms of site context, formation processes and technological organization employed by the hominins. It attempts to understand the characteristic features of the Acheulean technological organization at the site of Lalitpur. This has been done through the examination of the entire assemblage from the site and not just focusing on bifaces as the ‘type fossil’ of the Acheulean as has traditionally been done. For this purpose, the chaîne opératoire approach has been used to understand the entire technological organization from raw material procurement, to core reduction, blank production, modification into tools, use, resharpening, discard and alteration subject to post-depositional processes. Quantitative attributes have also been recorded to enable comparisons. Since the assemblage is recovered from near surface contexts, detailed studies of site context and formation processes were also undertaken to assess the integrity of the assemblage. Raw material has often been considered as an important factor affecting stone tools, particularly since the assemblage is predominantly made on granite, therefore detailed raw material studies were carried out. Finally the Acheulean at Lalitpur was compared it with other well studied assemblages in India, Africa and Europe to place the Indian Acheulean in global context The study of the technological organization of the Acheulean hominins at Lalitpur has helped in deriving a comprehensive picture of the stone tool technological repertoire of the Acheulean hominins. It has helped redefine the Indian Acheulean and place it in global context. Further it has helped in clarifying the concept of ‘Large Flake Acheulean’ and the behavioural implications of this technology. It has also highlighted the importance of ‘surface’ sites in the study of the Lower Palaeolithic, particularly in India and pointed out the importance of site formation studies in understanding the nature of Palaeolithic sites.
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Deomano, Edgar Dela Cruz. "Mechanism of Flake Drying and Its Correlation to Quality." Diss., Virginia Tech, 2001. http://hdl.handle.net/10919/28452.
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This research focuses on experimental investigations of the drying and bending properties of wood flakes. Three species (southern yellow pine, sweetgum, and yellow-poplar) were tested. Experiments on flake drying and effect of flake properties (cutting direction and dimension) and an external factor (temperature) were used to evaluate the flake drying process. Drying experiments were conducted using a convection oven. Bending properties of dried flakes were also measured. Modulus of elasticity (MOE), modulus of rupture (MOR), and strength at proportional limit (SPL) of flakes were measured based on Methods of Testing Small Clear Specimens of Timber (ASTM D143-94) using a miniature material tester.
The drying curve was characterized by a second-order/quadratic equation. This equation was then differentiated to get the drying rate curve. Observation on drying and drying rate curves revealed that the rate of moisture loss consists of two falling rate periods; no constant rate drying period was observed. First falling rate drying period is controlled by convective heat transfer. Bound water diffusion controls the second falling rate drying period.
Species, cutting direction, dimension, and temperature were found to have significant effect on drying rate of wood flakes. Southern yellow pine has the fastest drying rate followed by sweetgum then yellow-poplar. Differences in drying rate between species were attributed to differences in specific gravity and other factors. Radially-cut specimens have a slower drying rate than tangentially-cut specimens. There were also significant differences in drying rate between the four different flake dimensions. Thickness was found to be the more sensitive parameter in terms of dimensions. As expected, drying temperature also had highly significant effect on drying rate. An increasing trend in drying rate was observed as drying temperature increased.
Simulation of flake drying using a numerical model yielded a different result. Simulated flake drying has two drying periods: a constant rate and falling rate. Moisture of the flake decreases constantly and surface temperature increases rapidly to boiling point and remains there in the constant rate drying period. During the falling rate period, rate of moisture transport is limited by the ability of water to diffuse through wood and flake temperature starts to rise.
Bending properties were found to vary between and within the three species. Southern yellow pine had the lowest bending stiffness and strength followed by sweetgum while yellow-poplar had the highest bending properties. Radially-cut specimens were found to have lower MOE, MOR, and SPL than tangentially-cut specimens. Drying temperature was also found to have a significant effect on bending stiffness and strength. A decreasing trend in bending properties was observed when drying temperature was increased.Ph. D.
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Desai, Shanta Anand. "Fabrication and analysis of highly conducting graphite flake composites." Thesis, University of Leeds, 2006. http://etheses.whiterose.ac.uk/4046/.
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Graphite has high in-plane thermal conductivity and is a potential candidate to combat the thermal management problems in high density electronic devices. However, the properties of graphite are not fully exploited and this study was carried out with the aim of fabricating and analysing high thermally conducting graphite based composites. Model composites were prepared with three different average flake sizes: 180 μm, 300 μm and 600 μm. The constituents( flakes and binders) were characterised in terms of density, carbon yield and crystallographic perfection using combination of techniques. The electrical resistivity of a single flake was found to be 0.6 μS2 m. A fabrication route was developed using 75% starting volume fraction (67% - 72%) estimated volume fraction in the composite) of small flake graphite. A high volume fraction was used so as to obtain composites with properties dominated by the flakes. The selection of the optimum route of fabrication was based on achieving the lowest electrical resistivity of the composite after carbonisation (1000 °C). An extensive study was carried out on composites prepared using 75% (starting volume fraction) flakes. The mis-alignment of the 002 plane was found to decrease with an increase in the flake size. The optical texture of small flake composites showed that the binder was inhomogeneously distributed and was observed to shrink away from the flakes whereas in the case of composites with large flakes, the binder was found to wet the flakes. The layers of the binder were also found to align along the basal planes of the flakes in the vicinity of the flakes. The composites with small flakes were found to be `brittle' whereas the large flake composites showed a more `ductile' behaviour. The Young's modulus and work-of-fracture were estimated from load versus extension curves. Raman studies showed an increase in the a-direction coherence length in the binder with an increase in heat-treatment temperature and the electrical resistivity of the composites was found to decrease with increase in flake size and heat-treatment temperature. The thermal conductivities were determined and samples were imaged in a thermal microscope. Comparison between quantitative thermal conductivity and that predicted using Lavin's relationship showed that Lavin's relationship is not applicable to these composites. A thermal conductivity of 655 W/m K (160% of that of copper) was achieved in graphitised large flake composites. The volume fraction of graphite was varied (estimated volume fraction 45%-75% in the composite) and graphitised large flake composites were studied. The density of the composites increased with an increase in the volume fraction whereas the mis-alignment of the 002 plane was found to decrease with an increase in the estimated volume fraction of graphite up to -70%. When the estimated volume fraction of graphite was further increased (-75%), the mis-alignment was found to increase. This was attributed to the microstructure which showed high packing density giving rise to twisting and distortion of flakes in the composite. Existing composite-type models failed to correctly predict the transport properties and hence, a first approach to developing a model specifically for these composites was attempted. However, due to their complex nature and insufficient information to define the modelling parameters its validity is uncertain. A thermal conductivity of 750 W/m K (190% that of copper) and density -1.8 g/cm3 (nearly one fourth of that of copper) and all this at relatively lower cost was achieved in graphitised large flake composites with -75% estimated volume fraction of graphite. This material is particularly attractive to combat thermal management problems.
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Castillo-Bozzo, Ricardo N. "A fracture mechanics study of flake graphite cast iron." Thesis, Imperial College London, 1985. http://hdl.handle.net/10044/1/37651.
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Flake, Stephan [Verfasser]. "UML-Based Specification of State-Oriented Real-Time Properties / Stephan Flake." Aachen : Shaker, 2003. http://d-nb.info/1170545858/34.
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Orzechowski, Simone. "Otto Flake et le roman : de la révolte à la sagesse." Paris 4, 1995. http://www.theses.fr/1995PA040263.
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Ecrivain, essayiste, journaliste, Otto Flake (1880-1963) a pris une part active à la vie culturelle allemande de la première moitié de notre siècle. Par le recours à une pluralité de méthodes, par l'application de catégories empruntées aux théories reconnues du genre narratif et par un élargissement significatif du corpus de référence, la présente étude se voudrait une contribution à une meilleure connaissance du romancier, aujourd'hui tombe dans l'oubli et traite de manière toujours fragmentaire par la critique. L'esquisse de la carrière littéraire de Flake et l'examen de la conception qu'il a de l'écrivain, de sa fonction et de son activité créatrice constituent les premières étapes de ce travail. Elles sont suivies de l'analyse des théories littéraires qui, dans la phase suivante, sont confrontées avec la pratique romanesque de l'auteur. Au total, il apparait qu'à une période de révolte succède une prise de conscience des dangers liés à la rupture: Flake acquiert la conviction que le remède aux maux d’un monde moderne se trouve dans une adhésion aux valeurs éprouvées, au plan de l'esthétique tout autant que dans le domaine des idées et des convictions personnelles. A l'interrogation permanente sur la place de l'individu au sein de la nation, qui est un motif constitutif de la majeure partie des romans, Flake apporte des réponses successives qui vont du conflit à la réconciliation avec la communauté nationale. C'est la une confirmation patente de ce parcours qui s'inscrit dans les grands débats de la modernitéOtto Flake (1880-1963) took a prominent part in the German cultural life of the first half of our century as writer, essayist and journalist. Based on a plurality of methods, on categories which are borrowed to the admitted theories of the narrative genre and on a broader corpus of references, the present study aims to be a contribution to a better knowledge of the novelist, who has nowadays fallen into oblivion and who is always fragmentary considered by the critics. The sketch of flake's literary career and the examination of his conception of the writer of his function and his creative activity constitute the first stages of this work. They are followed by the analysis of the literary theories, which are confronted with the novels in the next phase. On the whole, it appears that, after a time of revolt, Flake realizes the dangers of the rupture: he is progressively convinced that the best way to remedy for the ails of the modern world is to adhere to traditional aesthetical philosophical and personal values. To the permanent question of the place of the individual in the nation Flake gives answers which are stretching from the conflict to the reconciliation with the national community. This is an obvious confirmation of Flake's way which is to insert into the great debates of the modernity
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Carlsson, Markus. "Konstruktion av beslag med dörrfunktion till spridarlucka." Thesis, Uppsala universitet, Industriell teknik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-203252.
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This thesis was performed at Zetterbergs Industri AB. Zetterbergs is designing, building and mounts body systems for trucks, including dumpers and tippers. The assignment for the thesis was to design a door hinge for a spreader gate. The spreader gate is the top of the two tailgates on a dumper or tipper and opens back and outwards when tipping the cargo. The spreader gate controls the mass flow of the material being tipped. Zetterbergs want to offer their customers an opportunity to also open the spreader gate as a door and place it along the outside of the tipper to get easier access to the platform when loading equipment. They already have an existing solution for both the tipper and the dumper, but there is a need to improve and coordinate these solutions. The existing solution is not entirely rigid which causes problems of sagging when used, and a result of this is heavy lifting for the operator. The process with designing a new hinge began with an initial study where, among others, the existing hinge and prototype solutions of the hinge at Zetterbergs were examined. To get to understand the process and which parts that needed to be taken into consideration when designing, a participation in the production was made. The initial study was finalized with the preparation of a user and technical specification. Following the initial study several concepts was generated with a method called “ the five step method”. Afterwards the concepts were evaluated and compared which lead to the selection of one of the concepts for a final design. The result of this thesis is a door hinge with tree different configurations. Those three configurations were made to fit the combinations between tipper and dumper as well as aluminum and steel hatch. The hinges are similar to each other and only a few details separate them. All components in the door hinge are adjusted for the production at Zetterbergs. The door hinge is designed in a way that prevents the operator from using it improperly.
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Gu, Hong-mei. "Moisture Gradient Measurement During Kiln Drying of Red Oak." Thesis, Virginia Tech, 1997. http://hdl.handle.net/10919/37027.
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The key to improving drying quality and reducing drying time and energy consumption lies
in understanding and controlling moisture movement during drying. As wood dries, strains
and stresses develop as a result of restraints imposed by moisture gradients and differential
shrinkage in wood. So accurately measuring the moisture gradient in wood during drying
will be helpful to improving drying quality.
In this project, moisture gradients in red oak will be measured through four different techniques----bandsaw slicing, Forstner bit layering, flaking and razor blade slicing. The first two techniques are found in the literature. The last two are developed in this study. The results obtained with these four techniques were compared, and it was found that the newly developed techniques could get moisture gradients that were closer to the true value.
The thickness of the slice was assumed to affect measuring the moisture gradient because of the environmental influences. So a thickness series was tested with the two new technique----flaking and razor blade slicing. The results showed that there was no slice or flake thickness effect on the moisture gradients.And an optimum slice and flake thickness was determined for the wood industries and research studies.
Finally, the directional effect on transverse moisture movement during kiln drying was
examined through measuring moisture gradients in the tangential and radial directions of
wood. The results showed that moisture moved slightly faster in the radial direction than
in the tangential direction during kiln drying and the moisture gradients in the tangential
direction were slightly steeper than those in the radial direction.
Master of Science
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Shimelmitz, Ron, Steven L. Kuhn, Avraham Ronen, and Mina Weinstein-Evron. "Predetermined Flake Production at the Lower/Middle Paleolithic Boundary: Yabrudian Scraper-Blank Technology." Public Library of Science, 2014. http://hdl.handle.net/10150/621336.
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UA Open Access Publishing FundWhile predetermined de´bitage technologies are recognized beginning with the middle Acheulian, the Middle Paleolithic is usually associated with a sharp increase in their use. A study of scraper-blank technology from three Yabrudian assemblages retrieved from the early part of the Acheulo-Yabrudian complex of Tabun Cave (ca. 415–320 kyr) demonstrates a calculated and preplanned production, even if it does not show the same complexity and elaboration as in the Levallois technology. These scraper dominated assemblages show an organization of production based on an intensive use of predetermination blank technology already in place at the end of the Lower Paleolithic of the Levant. These results provide a novel perspective on the differences and similarities between the Lower and Middle Paleolithic industries. We suggest that there was a change in the paradigm in the way hominins exploited stone tools: in many Middle Paleolithic assemblages the potential of the stone tools for hafting was a central feature, in the Lower Paleolithic ergonometric considerations of manual prehension were central to the design of blanks and tools.
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Nag, Kaushik. "Manufacture and synthesis of a dark micro magnetic flake powder for forensic application." Thesis, University of Central Lancashire, 2010. http://clok.uclan.ac.uk/18853/.
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In the study a novel method for synthesis of a dark magnetic flake powder for detecting latent fingerprint has been developed. Even though, flake powders ,of aluminium, brass and highly reflective magnetic iron flake are already in use in crime scenes , it is highly desirable to develop a suitable darker variety of magnetic flake powder for print development on light background surfaces. In order to achieve rapid production of dark metal flakes, a new high energy prototype vibratory mill has been designed, manufactured and develo ed. The design concepts were developed following a comprehensive review of the various commercially available milling devices and undertaking some initial experimentation. The mechanical milling process which results in changing the particle morphology of starting atomised iron powder to flaky shaped powder was investigated in terms of different milling phases like micro forging, fracture and agglomeration. The effect of milling process parameters on the flake quality was investigated. It was shown that the amount of stearic acid content, ball packing fraction and weight loading were important parameters in determining the final flake qualities. The quality of latent fingerprint development with the dark flake powder was investigated. Some of the flake powders produced excellent ridge quality details with good adherence quality on a range of background surfaces. The present study has been able to establish the relationship between the visual characteristics ( dark) and adherence property of the flake fingerprint powder with respect to the particle dimensions and surface characteristics of the flakes. It was also found that finer flakes are darker in colour and the low weight percentage of stearic acid has produced the best adherence quality for the dark flake powder. Some unique relationship between the flake dimensions with the nature of the print deposit was also established as it was found that slightly coarser flakes are suitable for heavy print deposit whereas finer flakes are more sensitive to aged prints. Further, the role of process variables in influencing the milling process were established such that optimum conditions by vibration milling can be determined to obtain dark flakes of desired quality. While the weight loading significantly influenced the milling behaviour of the powder, the role of stearic acid as an additive was found to influence the surface quality of flakes, besides restricting particle welding. Increasing the pre determined theoretical ball size does not result in faster milling, but increasing the ball packing fraction from 50% to 70% has proved to be more effective. Some relation with the oxidising behaviour of the powder with vibration milling has also been established. Moreover, the study has demonstrated that high energy milling by a vibration mill can be utilised for consistent production of a novel dark magnetic flake powder.
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Sandgathe, Dennis Michael. "The detection of unmodified flake tools in archaeological assemblages in the Eastern Slopes, Alberta." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/MQ34322.pdf.
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Moore, Mark W. "Diagnostic flake analysis : a replication-based method for reconstructing reduction techniques, strategies, and technologies." Virtual Press, 1990. http://liblink.bsu.edu/uhtbin/catkey/724566.
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Diagnostic flake analysis is based on the concept that distinct flintknapping techniques produce distinctive flakes. Seen in this light, the information potential of flakes is enormous. Unfortunately, this information is virtually lost in analyses based upon size-grading a flake assemblage or separating flakes statistically based on a few "key" attributes. The intent of this study is to provide and apply a well-integrated analytical approach based upon the diagnostic flake concept.In order to integrate the static lithic artifacts to the dynamic behavior that produced them, a generalized flow chart model of the knapping event is developed. The flow chart model emphasizes the debitage produced during knapping, rather than finished lithic tools. The flow chart model is described in detail, and the terms"technology", "strategy", and "techniques" are defined and contrasted.A total of 30 reduction experiments were conducted in the course of this study, producing an estimated 27,000 flakes and flake fragments. Based on this sample and previous work conducted by Flenniken (n. d. ) and others, nine diagnostic flake types and three significant flake attributes are defined.An ideal methodology for a lithic analysis is developed. This ideal methodology includes: 1) assessing the types of raw materials present on a site; 2) reconstructing the technology based on negative-flake scars on finished tools; 3) flake refitting; 4) classifying flakes into the diagnostic flake categories nonstatistically and polythetically, with special emphasis placed on recognizing previously unidentified diagnostic flake types; 5) developing a flow chart model of reconstructed prehistoric technology; and 6) summarizing the flow chart i n verbal form.The methodology is applied to the Middle and Late Woodland components of the stratified All Seasons site located in central Indiana. Analysis of the Middle Woodland assemblage results in the recognition and definition of conical core flake blanks.The methodology is applied to a blind test manufactured by Donald Cochran to assess bias that may have been introduced into the flake type definitions by using debitage produced only by the author. Cochran's behavior is accurately reconstructed.Finally, the results of the study are discussed, and the study's strengths and weaknesses are determined. Diagnostic flake analysis is found to be a powerful approach that derives an optimal amount of high-quality information from a chipped stone assemblage.Department of Anthropology
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Leonardo, Carmignani. "From the flake to the blade: the technological evolution of the Middle Paleolithic blade phenomenon." Doctoral thesis, Universitat Rovira i Virgili, 2017. http://hdl.handle.net/10803/440521.
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El tecno-complex europeu del Paleolític Mitja mostra grans tendències cronològiques en els canvis de la industria lítica i una diversitat tècnica interna que és difícil d’explicar dins d’un marc homogeni.
Aquest treball introdueix una perspectiva tecnològica per entendre aquesta diversitat tècnica, basant-se en la comparació de quatre seqüencies mosterianes: Bau de l’Aubesier and Payre, al sud-est de França, Riparo Tagliente al nord d’Itàlia i Grotta del Cavallo al sud d’Itàlia.
Dins del mosaic tecnològic, que és el principal tret del Paleolític Mitja europeu, la producció laminar assumeix un paper poc clar. Les anàlisis tècniques dels complexos industrials recuperats a tots quatre jaciments mostren una discontinuïtat de les estratègies de reducció laminar. Des de un punt de vista comparatiu, però, els canvis tècnics no apareixen amb el mateix ritme a les quatre seqüencies.
A Bau de l’Aubesier i a Payre es van reconèixer diferents característiques tècniques. A Payre el predomini de la producció d’ascles contrasta amb l’associació de làmines i ascles com a productes finals reconeguts a Bau de l’Aubesier. Aquesta variabilitat no sembla estar relacionada amb factors externs com poden ser les matèries primes o altres activitats.
D’altra banda, els jaciments de Riparo Tagliente i de la Grotta del Cavallo comparteixen una combinació de la producció Levallois i laminar adreçades a la generació de productes finals diferents.
Finalment, una producció de laminetes reconeguda a Bau de l’Aubesier durant el MIS5 i més tard a la Grotta del Cavallo durant el MIS4-3, presenta una evolució tecnològica no lineal a través del temps i de l’espai.
Proposem que aquestes diferents modalitats de canvi són el resultat de una profunda diversitat tecnològica dels grups humans que van poblar el sud del continent europeu durant el Paleolític Mitjà .Los tecnocomplejos Europeos del Paleolítico Medio muestran grandes tendencias cronológicas en los cambios de la industria lítica, y también una diversidad técnica interna que es difícil de explicar dentro de un marco homogéneo. Para entender esta diversidad técnica, se ha introducido una perspectiva tecnológica basada en la comparación de cuatro secuencias musterienses: Bau del’Aubesier y Payre, en el sudeste de Francia; Riparo Tagliente del norte de Italia y Grotta del Cavallo del sur de Italia. En el mosaico tecnológico, que es la peculiaridad del Paleolítico Medio Europeo, la producción laminar asume un rol poco claro. Los análisis tecnológicos de los cuatro sitios analizados, muestran una discontinuidad en la estrategia de reducción laminar. Desde una perspectiva comparativa, los cambios tecnológicos no aparecen con el mismo ritmo en las cuatro secuencias: en Bau de l’Aubesier y Payre distintos rasgos tecnológicos se han reconocido. En Payre el dominio en la producción de lascas, contrasta con la asociación de láminas y lascas como productos finales reconocidos en Bau de l’Aubesier. Esta variabilidad parece no estar asociada a factores externos, como materias primas u otras actividades. Riparo Tagliente y Grotta del Cavallo presentan una combinación de Levallois y producción laminar, dirigida a la elaboración de diferentes productos finales. Finalmente, una producción de lamelas es reconocida en Bau de l’Aubesier durante el MIS 5, y más tarde también, en Grotta del Cavallo durante el MIS 4-3, lo que muestra una evolución tecnológica no linear a través del tiempo y del espacio. Se sugiere que estas distintas modalidades son el resultado de una profunda diversidad tecno-cultural de los grupos humanos que poblaban el sudeste europeo durante el Paleolítico Medio.
The European Middle Paleolithic technocomplex shows some large chronological trends in the lithic industry changes, and also an internal technical diversity which is difficult to explain in a homogeneous framework. We introduce a technological perspective to go through this technical diversity, based on the comparison of four Mousterian sequences: Bau de l’Aubesier and Payre in southern-east France, Riparo Tagliente in northern Italy and Grotta del Cavallo in southern Italy. In the technological mosaic, which is the peculiarity of the European Middle Paleolithic, blade production assumes a unclear role. Technical analyses show a discontinuity of blade reduction strategies, shared by the industries of the four sites. In a comparative perspective, technical changes don’t appear at the same rhythm in the four sequences: in Bau de l’Aubesier and Payre different technological features has been recognized. At Payre dominance of production of flakes contrast with the association of blade and flakes end-products recognized at Bau de l’Aubesier. This variability does not seem to be linked to external factors such as the raw materials or other activities. Riparo Tagliente and Grotta del Cavallo share a combination of Levallois and laminar production aimed to produce distinct end products. Finally, a bladelets production recognized at Bau de l’Aubesier during the MIS 5 and later on at Grotta del Cavallo during the MIS 4-3 display a non-linear technological evolution through time and space. We suggest that these different change modalities are the result of a deeper techno-cultural diversity of human groups populating the southern Europe during the Middle Paleolithic.
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Eck, Thomas Peter. "Effect of sorghum grain flake density on site and extent of digestion in feedlot steers." Diss., The University of Arizona, 1991. http://hdl.handle.net/10150/185684.
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Experiments were conducted to determine the effects of sorghum grain flake density on site and extent of nutrient digestion in beef steers. Sorghum grain was steam-flaked to densities of .41, .36, .31 and .26 kg/L. Diet digestibility was determined during the growing and finishing periods of a feedlot performance trial with dietary grain levels of 50 and 80%, respectively. Starch digestion was increased from 92 to 98%, and from 98 to 99%, on growing and finishing diets, respectively, in response to decreased flake density. Digestion of dry matter and energy was increased in growing diets but decreased in finishing diets as flake density in the diets decreased. Fiber digestion was not influenced in growing diets but decreased in finishing diets. In an experiment using cannulated steers fed diets with 50% grain, flow of starch at the duodenum was reduced 50% (466 vs 232 g/d) as flake density was decreased from .41 to .26 kg/L. Starch digestion was increased in each segment of the digestive tract with the greatest response occurring in the rumen (83 vs 92%, for .41 and .26 kg/L, respectively). In another experiment using cannulated steers fed 80% grain diets, starch flow from the rumen was also reduced by 50% (694 vs 371 g/d) by decreasing flake density from .41 to .36 kg/I. Starch digestion was improved throughout the digestive tract. Ruminal, intestinal and total tract starch digestion was comparable when grain was flaked to .36 kg/s or less. In conclusion, flaking of sorghum grain over a range of flake densities primarily affected starch digestion. As flake density in the diet decreased, starch digestion increased in all three studies. The largest differences among treatments in ruminal, intestinal and total tract digestion occurred between the .41 and .36 kg/L treatments. Starch digestion was similar when sorghum grain was flaked to .36, .31 or .26 kg/L. Response pattern for protein digestion followed that for starch digestibility. Effect of flake density on digestion of other nutrients was not consistent among the three experiments.
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Casey, Linda J. "Changes in wood-flake properties in relation to heat, moisture, and pressure during flakeboard manufacture." Thesis, Virginia Polytechnic Institute and State University, 1987. http://hdl.handle.net/10919/101369.
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In an attempt to relate different pressing parameters to changes in test flake properties, eight hot-press cycles were used in the manufacture of 24 flakeboard panels, with 2 levels each of platen temperature, initial mat moisture content, and press closing time. Temperature and gas pressure occurring at the face and core of the mat, along with platen pressure, were recorded throughout the press cycles. Data is presented graphically as a function of press time. Face and core equilibrium moisture content conditions throughout the press cycle were estimated for each panel based on corresponding temperature and gas pressure information. Time-integral data on temperature, gas pressure, and platen pressure were determined. Simple linear regressions were performed in an attempt to relate the actual test flake environment to changes in properties.
Two hundred and fifty yellow-poplar (Liriodendron tulipifera) test flakes were consolidated within the face and core of flakeboard mats and recovered. Their individual pre- and post-pressing thickness and specific dynamic bending modulus values were determined and compared with respect to changes in pressing parameters. Platen temperature, initial mat moisture content, and test flake location within the mat were all involved in significant two-way interactions in their effects on flake properties.M.S.
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Lemos, Lorena Ranucci. "INFLUÊNCIA DE DIFERENTES TEORES DE DEXTRANA E AMIDO EM AÇÚCAR CRISTAL NA FORMAÇÃO DE FLOCOS EM SOLUÇÕES ÁCIDAS CARBONATADAS E SOLUÇÕES ALCOÓLICAS." UNIVERSIDADE ESTADUAL DE PONTA GROSSA, 2012. http://tede2.uepg.br/jspui/handle/prefix/697.
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Previous issue date: 2012-08-03Several investigations have been performed to determine the influence of the sugarcane composition in the quality of its products, especially crystal sugar. There is interest in studies about dextran and starch to be causative agents of major problems during the processing of sugarcane and also to be related to the appearance of flakes or precipitated in alcoholic drinks and acidic carbonated beverage. The objective of the present work was to evaluate the influence of these polysaccharides in the formation of flakes in acidic carbonated and alcoholic solutions. Samples of crystal sugar (n = 21) produced in the central-southern Sao Paulo state were analyzed for quantification of dextran and starch and values between 15.39 ± 0.38 and 830.25 ± 2.58 mg/kg and between 49.11 and 299.92 ± 1.14 ± 1.05 mg/kg were found for dextran and starch, respectively. The test evaluated the formation of flake in alcoholic solution at 55 and 89 % v/v ethanol. The 55 % v/v ethanol was performed to read the absorbance of the samples and values between 0.018 ± 0.001 and 1.063 ± 0.010 NTU were found. For the 89 % v/v ethanol solution the formation of flakes in the first 15 hours of storage the test solution was observed. There was reduction of starch content in solution with the methodology used by alcoholic flake and the reduction varied between 13.78 and 34.15 %. The test evaluated the formation of acid flake following the standard methodology and modification of the method by using a 0.8 μm filter for removal of starch. The turbidity readings were lower when using the modified method. The results obtained for the solutions tested according to standard methodology ranged from 3.72 ± 0.17 to 33.46 ± 6.31 NTU and by using the modified method they were between 1.94 ± 0.08 and 10.97 ± 1.04 NTU. All tests showed that dextran and starch present in the samples of crystal sugar show a positive correlation with the results of acid flake and alcohol flake. The formation of these two types of flakes were also interdependent (has a relation).
Várias pesquisas estão sendo realizadas com o objetivo de determinar a influência da composição da cana-de-açúcar na qualidade final de seus produtos, em especial no açúcar cristal. Existe interesse em estudos sobre dextrana e amido por serem agentes causadores de sérios problemas durante o processamento da cana, estando relacionados ao aparecimento de flocos ou precipitados em bebidas ácidas carbonatadas e em bebidas alcoólicas destiladas. O objetivo desse trabalho foi avaliar a influência desses polissacarídeos na formação de flocos em soluções ácidas carbonatadas e em soluções alcoólicas. Amostras de açúcar cristal (n = 21) produzidas na região centro-sul do Estado de São Paulo foram analisadas para quantificação de dextrana e amido. Foram realizados testes para avaliação da formação de floco alcoólico em soluções hidroalcoólicas a 55 e a 89 % v/v etanol e teste para avaliação da formação de floco ácido seguindo método padrão e método com modificação através da utilização de filtro 0,8 μm para retirada do amido. Foram encontrados teores de dextrana entre 15,39 ± 0,38 e 830,25 ± 2,58 mg/kg e teores de amido entre 49,11 ± 1,14 e 299,92 ± 1,05 mg/kg nas amostras de açúcar cristal analisadas. A 55% v/v de etanol foi realizada a leitura de absorbância das amostras segundo teste de floco alcoólico, sendo encontrados valores de turbidez entre 0,018 ± 0,001 e 1,063 ± 0,010 NTU. A 89 % v/v de etanol, foi observada a formação de flocos nas primeiras 15 horas de estocagem da solução teste. Ocorreu redução do amido presente na solução com o método de floco alcoólico utilizado e as reduções variaram entre 13,78 e 34,15%. Foram verificadas reduções das leituras de turbidez com a utilização do método modificado de floco ácido. Os resultados obtidos para as soluções testadas, de acordo com o método padrão, variaram de 3,72 ± 0,17 a 33,46 ± 6,31 NTU e com a utilização do método modificado, ficaram entre 1,94 ± 0,08 e 10,97 ± 1,04 NTU. Todos os ensaios realizados demonstraram que o amido e a dextrana presentes nas amostras de açúcar cristal apresentam relação positiva com os resultados de floco ácido e floco alcoólico. A formação desses dois tipos de flocos se mostrou diretamente relacionada (apresenta relação positiva).
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Flake, Albrecht [Verfasser]. "Kooperationspotenziale 'Grüner Werkstätten' und Beschäftigungspotenziale landwirtschaftlicher Betriebe sowie des branchennahen Handwerks für Menschen mit Behinderung / Albrecht Flake." Kassel : Universitätsbibliothek Kassel, 2013. http://d-nb.info/1043823913/34.
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Andersson, Staffan, and Mikael Jansson. "Framstam till timmerlastbil." Thesis, Karlstad University, Faculty of Technology and Science, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-2660.
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Examensarbetet har gjorts åt Höglunds flak i Säffle och behandlar en ny framstam till timmerlastbilar.
En framstam är ett lastskydd som förhindrar stockarna på en timmerlastbil från att tränga in i hytten vid en kollision. Framstammen används även vid lastning som ett mothåll att slå stockarna emot.
Kraven på framstammen från företaget är
• Lättare konstruktion
• Samma utböjning vid slagprov, ytbelastning och böjbelastningsprovning som nuvarande modell
• Billigare eller samma pris som föregående modell
• Klara proven enligt SS 2563, SS 2564
• Vara estetiskt tilltalande för kund
• Anpassningsbar höjd
• Om möjligt få så mycket tillverkning som möjligt till den egna verkstaden
Arbetet delades in i två delar där en del är att konstruera plåten och hur denna skall styvas till. Den andra är att konstruera staken som håller upp plåten och tar den största delen av slagkraften.
På framstamsplåten togs det fram 2 koncept.
Bockningskonceptet.
Konceptet består av en aluminiumplåt 6082-T6 som bockats till en L-profil runt kanterna för att styva upp plåten
Fyrkantsprofil.
Detta koncept består av en fyrkantsprofil i aluminium som nitas fast mot plåten.
På staken togs det fram tre koncept. Alla tre är beräknade med att vara i samma material ett höghållfast stål vid namn Domex 650 med en sträckgräns på ca 650Mpa.[5]
JL-profilen
Är en profil som är lätt att tillverka genom bockning och är lätt att fästa in i både plåten och i rambalken.
I-profilen
I-balken är gjord med en större fläns mot plåten för att underlätta vid infästning och en mindre fläns på andra sidan för att minska vikten. På grund av att detta inte är en original balk så kommer denna modell att strängpressas.
W-profilen
W- profil som även denna skulle stängpressas och är även lätt att fästa mot plåten. Den har tagits fram med tanken på en T-balk som sedan stadgats upp med två stycken förstyvningar.
Fyrkantröret har en lägre vikt på 19 kg i jämförelse med rör- profilen, detta motsvarar en viktbesparing på 55%.
I-profilen klarar att ta upp 0,6kJ mer än Z-profilen samtidigt som den är 23 kg och 23%
lättare.
The work is done for the company Höglunds flak in Säffle and aims to develop a new front wall to a timber truck.
A front wall is what protects the cabin from the logs in case of a collision. The front wall is also used while loading the truck as a loading fixture to beat the logs against.
The requirements for the front wall from the company are:
• Easier construction
• The same deformation at impact testing, surface testing and bending load as the original.
• Cheaper or the same price as the previous model
• Withstand the standardization SS 2563, SS 2564
• Be attractive to the customer
• Customizable height
• If possible, get as much production as possible to the own workshop
The work was divided into two parts where one is to make the plate and how to make it rigid. The second is the beams which are going to keep up the plate and takes the greater part of the impact force.
Two concepts on the front wall plate, both is of the same material 6082-T6.
Bending concept.
The concept consists of an aluminium plate which is bended to an L-profile around the edges to rigid up the plate.
Square concept.
This concept consists of a square tube in aluminium which is riveted firmly against the plate.
Three concepts on the beams. All three are estimated to be in the same material Domex 650
JL-profile
Is a profile that is easy to manufacture by bending and is easy to mount on both the plate and in the frame beams.
I-profile
The I-beam is made with a larger flange to the plate in order to facilitate the attachment and a small flange on the other side to reduce weight. However, because this is not an original beam it will be manufactured through extrusion.
W-profile
W-profile is going to be extruded and is also easy to attach to the plate. It has been developed with the idea of a T-beam which then is stated up with two webs.
Of the two plate concepts it was the Square concept which was best suited one. The bending concept was not chosen because the material of the plate was for brittle and couldn’t be bent as much as wanted.
The analysis of the plate was made according to the standard SS2563, SS 2564 with a pressure of a certain distance from the base.
The FEM analysis at the plate shows that there is no residual deformation, which is the same as the original plate. The square pipe has a lower weight with 19 kg which is 55% lighter compared with the circular pipe profile.
The profile is able to take up 0,6 kJ more than the Z-profile and 23kg and 23% lighter
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Golt, Michael C. "Magnetic and dielectric properties of magneto-dielectric materials consisting of oriented, iron flake filler within a thermoplastic host." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 150 p, 2008. http://proquest.umi.com/pqdweb?did=1597633721&sid=13&Fmt=2&clientId=8331&RQT=309&VName=PQD.
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Cohen, Liam Augustus. "Fabricating Van der Waals heterostructures with air sensitive materials : a study of flake Bi₂Sr₂CaCu₂08₊x." Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/118024.
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Thesis: S.B., Massachusetts Institute of Technology, Department of Physics, June 2018.Cataloged from PDF version of thesis.
Includes bibliographical references (pages [96]-[97]).
by Liam Augustus Cohen.
S.B.
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Layden, Aisling. "Global study of lake surface water temperature (LSWT) behaviour and the tuning of a 1-dimensional model to determine the LSWTs of large lakes worldwide." Thesis, University of Edinburgh, 2014. http://hdl.handle.net/1842/9928.
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Lake surface water temperatures (LSWTs) of 246 globally distributed large lakes were derived from Along-Track Scanning Radiometers (ATSR) for the period 1991 to 2011. These LSWTs, derived in a systematic manner, presents an ideal opportunity to study LSWT behaviour on a global scale. In this thesis, the annual cycles of lake-mean LSWTs derived from these data quantify the responses of large lakes’ surface temperatures to the annual cycle of forcing by solar radiation and the ambient air temperature. Minimum monthly net surface solar irradiance (netSSI) strongly influences minimum LSWTs of non-seasonally ice covered lakes (where lake-mean LSWT remains above 1 ºC throughout the annual cycle), explaining > 0.88 (R2 adj) of the inter-lake variation in both hemispheres. In some regions, for seasonally ice covered lakes (where lake-mean LSWT remains below 1 ºC for part of the annual cycle) the minimum monthly netSSI is a better predictor than latitude, of the length of the frozen period, which shows the importance of local cloud climatological conditions. Additionally, at lake locations between 1º S to 12º N, the netSSI, shown to peak twice annually, is reflected in the LSWT annual cycle. The summer maximum LSWTs of lakes from 25º S to 35º N show a linear decrease with increasing altitude; -3.76 + 0.17 ºC km-1 (R2 adj = 0.95), marginally lower than the corresponding air temperature -4.15 + 0.24 ºC km-1 (R2 adj = 0.95) decrease with altitude. The start and end of the period where the lake-mean LSWT is greater than 4 ºC shows strong correlation with the spring and autumn 0 ºC air temperature crossing days, (R2 adj = 0.74 and 0.80 respectively). The temporally and spatially resolved LSWT observations allows for a greater practical understanding of LSWT behaviour of large lakes. For example, lakes with a greater LSWT annual range have more observed variability in the LSWT extremes, highlighting that they may be more responsive to changes in the climate than lakes with a low annual range. The nighttime LSWT trends show stronger warming than day-night trends in the all regions, except Europe. The lake centre LSWT trends and absolute values can be generally considered representative of the lake-mean LSWT trends and absolute values. The observed LSWT time series are used to tune a 1-dimensional thermodynamic lake model, FLake. By tuning FLake using only 3 basic lake properties, shown by myself to have the most influence over LSWTs (depth, snow and ice albedo and light extinction co-efficient), the daily mean absolute differences for 244 lakes is reduced from 3.38 + 2.74 ºC (untuned model) to 0.85 + 0.61 ºC (tuned model). The effect of wind speed, lake depth, albedo and light extinction co-efficient on LSWTs is demonstrated throughout the tuning process. The modelled summer LSWT response to changes in ice-off is strongly affected by lake depth and latitude explaining 0.50 (R2 adj, p = 0.001) of the inter-lake variation in summer LSWTs. Lake depth alone explains 0.35 (p = 0.003) of the variation, highlighting the sensitivity of the summer LSWTs of deeper lakes to changes in the ice-off. Statistically significant summer/ maximum month modelled LSWT trends, from 1979-2011 are presented for lakes where the modelled LSWTs are strongly supported by observed LSWTs over the period of available observed LSWTs. For these lakes, the trends show LSWT warming of between 0.73 – 2.10 ºC for 29 lakes in northern temperate regions over the 33 year period (1979 – 2011). The modelled regional trends of all lakes over the same period show least warming in Africa of 0.30 ºC and the greatest warming in Europe, 1.35 º.
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Mis, Carolina. "Tjejer med smak kör Volvo med flak : En etnografisk studie om femininitet och flickskap inom A-traktorkultur." Thesis, Stockholms universitet, Institutionen för etnologi, religionshistoria och genusvetenskap, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-164818.
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This study draws from qualitative interviews with seven teenage girls in several areas of mid-Sweden. In various degrees, all girls participate in the A-traktor culture. The purpose of the study is to examine how teenage girls construct femininity in the A-traktor culture. It also focuses on how the subculture shape and constrains an A-traktor girlhood. The study showed that the girls participating in the subculture are doing femininity through different negotiations and strategies. The A-traktor girlhood negotiates conventional norms and practices within the subculture as well as with structural conventional norms related to young girls outside the subculture. In order to gain recognition as authentic members of the A-traktor culture, the girls adapt to the masculinized norms in the subculture. Hence, the A-traktor girlhood’s gender negotiations were constrained by the normative framework of the subculture. But the masculinized norms of the culture could also create opportunities for the girls to ”trouble” their performances of femininity to a greater extent compared with the time before entering the A-traktor culture. The A-traktor girlhood’s alternative discourses and practices gave the girls room to maneuver within and also in opposition to the masculinized codes and norms in the subculture. The spatial A-traktor culture and its masculinized normative framework could be used as a place where the girlhood could oppose to societal conventional notions of femininity. The study draws its theoretical framework from gender as performative, spatial orientation and intersectionality. Research on girlhood, youth culture and motor culture has also been essential in the process of analyzing constructions of femininity and girlhood in the A-traktor culture.
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Lancaster, David D. "Developing a Fly-Away Kit (FLAK) to support Hastily Formed Networks (HFN) for Humanitarian Assistance and Disaster Relief (HA/DR) /." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2005. http://library.nps.navy.mil/uhtbin/hyperion/05Jun%5FLancaster.pdf.
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Fisher, Erich Christopher. "A complex systems theory of technological change a case study involving a morphometrics analysis of Stone Age Flake Debitage from the Horn of Africa /." [Gainesville, Fla.] : University of Florida, 2005. http://purl.fcla.edu/fcla/etd/UFE0010480.
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Hochstedler, Robert A. "Implementation of a modular Fly away Kits (FLAK) for C4ISR in order to counter asymmetric threats in the coalition riverine and maritime theatres." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2006. http://library.nps.navy.mil/uhtbin/hyperion/06Jun%5FHochstedler.pdf.
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Thesis (M.S. in Systems Technology (Command, Control and Communications (C3))--Naval Postgraduate School, June 2006.Thesis Advisor(s): James F. Ehlert. "June 2006" Includes bibliographical references (p. 119-121). Also available in print.
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Savvakis, Vasileios. "Evaluation of FLake’s Performance on Water Temperatures and Surface Heat Fluxes at Lake Erken, Sweden." Thesis, Uppsala universitet, Luft-, vatten och landskapslära, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-380766.
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In many numerical weather prediction models, the presence of lakes is simulated crudely, with their effect being neglected in the resulting simulations. However, it has been shown how lakes effect not only their surrounding climate directly, but have an effect to the overall weather evolution and ecosystem. It is therefore vital to improve existing models to take lakes into account, by coupling with smaller models specificaly compiled for a reas with lakes. There have been several sophisticated models to parameterizelakes in a geographical area, which are, on the other hand, computationally expensive and time consuming. A model built specifically on simple physical assumptions, named FLake, aims to provide a solution that is not heavy computationally, but is accurate enough and contains all the necessary physics surrounding the heat budget and temperature of a given lake. For this project, FLake was tried on a lake close to Uppsala, named Erken, where the validity of the model was tested against data archives from Erken Laboratory’s measurement tower. The resulting simulations were very promising regarding the water temperatures, as well as giving out acceptable results for the surface heat fluxes above the lake and the duration of the ice period, as it was modeled by FLake and compared with ice data archives.
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Flake, Regina [Verfasser], Thomas K. [Gutachter] Bauer, and Christoph M. [Gutachter] Schmidt. "Migrants in Germany : the role of intergenerational relations in economic integration and labor market effects / Regina Flake ; Gutachter: Thomas K. Bauer, Christoph M. Schmidt ; Fakultät für Wirtschaftswissenschaft." Bochum : Ruhr-Universität Bochum, 2013. http://d-nb.info/1211175154/34.
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Flak, Michal [Verfasser], Axel A. [Gutachter] Brakhage, Erika [Gutachter] Kothe, and Bodo [Gutachter] Philipp. "Secondary metabolites in the interaction of Aspergillus fumigatus and Pseudomonas aeruginosa in cystic fibrosis sputum / Michal Flak ; Gutachter: Axel. A. Brakhage, Erika Kothe, Bodo Philipp." Jena : Friedrich-Schiller-Universität Jena, 2020. http://d-nb.info/1223023222/34.
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Rawson, Keith William. "Shear controlled orientation effects with injection mouldings produced by the SCORIM process." Thesis, Brunel University, 1997. http://bura.brunel.ac.uk/handle/2438/6380.
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Injection moulding using the process of Shear Controlled Orientation Injection Moulding (SCORIM) to enhance the aesthetic characteristics of plastics was investigated. Unsightly surface weld lines were successfully removed from highly reflective aluminium flake pigmented plastics by the application of a single macroscopic SCORIM shear when used in series with Bright Surface Moulding (BSM). A gonio spectrophotometer (GSP) was used for the quantitative characterisation of the Al flake pigmented mouldings as a measure of surface reflectivity and preferred angle of reflection. The different directional properties of surface reflectivities to either side of a conventional weld line are unacceptable, but were successfully reoriented approximately uniformly with the use of SCORIM and BSM moulding (i. e. SBM) used in series. SBM therefore provided an acceptable quality of surface finish for mouldings originally containing a weld line, without deterioration of mechanical properties. Indeed, some improvements in mechanical properties were observed. Translucent two-colour mouldings were used to successfully demonstrate the flow paths taken by sheared material during the application of macroscopic shears. The use of intermittent shearing to encapsulate shear oriented material in the solidifying layers, manifested original and profound aesthetic effects. This resulted from mixing the two colours and was reproducible and widely variable. The morphology of isotactic polypropylene (iPP) processed in this way and examined by light and electron microscopy revealed how only one or two intermittent shears were required to orient a large volume of the moulding in the shear direction. Moreover, U-shaped flow paths demonstrated that the easiest shear route was close to the mouldings edges, an observation supported by x-ray analysis. The addition of Al flake pigment was found to act as a heterogeneous nucleant for ß-spherulites. This acted as a suitable marker for the clear identification of the displaced weld interface using polarised light microscopy, of filled and unfilled iPP. y-phase was identified with the use of only one or two intermittent shears which reflects an increase in molecular alignment and consequent improved mechanical properties. The intensity of the y-phase increased with the volume of material sheared. Strong evidence was also obtained of a linear relationship between the logarithm of the time lapse between two intermittent shears and the corresponding values of a-phase index, crystallinity index and percentage crystallinity. The values of each increasing proportionally with the length of time used. Microhardness characterisation revealed anisotropy within SCORIM samples consistent with preferred orientation and increased modulus in the shear direction. The skin layers were characterised as the softest region through the thickness of SCORIM mouldings. The results of this work were used to provide the basis of a computer simulation of the SCORIM process under development at the University of Wales Swansea.
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Younger, Alexandra Carla. "Lithic Production at the Mesilla Phase Placitas Arroyo Site Complex Doña Ana County, New Mexico." Thesis, University of North Texas, 2019. https://digital.library.unt.edu/ark:/67531/metadc1538785/.
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This study of lithic analysis shifts attention from typological studies to explicitly behavioral analyses, complimenting studies of both intrasite and intersite patterns of variability and change. Analysis of several assemblages from the Placitas Arroyo site complex reveals changing patterns of raw material procurement and selection, core reduction strategies, as well as tool production and discard. The most striking result thus far is the quite uniform emphasis on flake production from well-prepared cores, and the near absence of manufacture or maintenance of bifacial tools, especially projectile points. Associated with common ground stone artifacts, the flaked stone materials may well represent intensive food processing. Regardless, the technological patterns being revealed by this approach illustrate a productive new means to gain insights into changing behaviors in the Jornada Mogollon cultural tradition.
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Loffler, German. "Microscopic analysis utilized in the identification of cutting, scraping and whittling activities on flake tools from the Qwu?gwes (45TN240), Hartstene, and Sunken Village (35MU4) sites in the central northwest coast of North America." Online access for everyone, 2007. http://www.dissertations.wsu.edu/Thesis/Fall2007/g_loffler_112707.pdf.
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Brujas, Marco Antonio. "Análise numérica e experimental dos efeitos da não-uniformidade da espessura em cascas finas cilíndricas rotativas." Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/3/3144/tde-08082007-165939/.
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Cascas cilíndricas circulares com uma pequena variação de espessura ao longo de seu comprimento, quando submetidas à rotação, apresentam em alguns casos, deslocamentos elásticos de sua superfície externa, tendendo a uma forma de um oval. O objetivo deste trabalho é estabelecer a relação entre a variação de espessura das cascas cilíndricas com a sua deformação devida às forças centrífugas medida durante a rotação utilizando-se dois enfoques, um experimental e outro numérico, no caso o método de elementos finitos (MEF). As cascas cilíndricas estudadas tiveram sua espessura de parede medidas por meio de aparelho de ultra-som, mas por serem fabricadas em ferro fundido cinzento, as suas lamelas de grafita atuam como refletores, o que torna a medição imprecisa. Os resultados da análise numérica encontrados se relacionam bem com os experimentais de maneira qualitativa, mas divergem na forma quantitativa. Modelos de cascas com variação de espessura imposta também foram criados e analisados usando-se o método de elementos finitos de forma a se avaliar o comportamento da casca cilíndrica sob diversas configurações de distribuição da variação da espessura. Sugere-se a pesquisa de novas tecnologias para medições por ultra-som de peças fabricadas de ferro fundido com grafita lamelar. Neste trabalho, a medição da forma oval foi feita utilizando-se sensores de proximidade do tipo \"eddy-current\".Circular cylindrical shells with small thickness variations along their body, when submitted to rotation, present, in some cases, elastic displacements of their outside surface induced by centrifugal forces leading to final oval like shapes. The main purpose of this study is to establish relationships between thickness variation of the cylindrical shells with their measured deformation during the rotation, due to centrifugal forces, using two approaches, one experimental and the other one numerical, in the latter case the finite element method (FEM). The studied cylindrical shells had their wall thickness measured by means of an ultrasound device. The used material is flake graphite cast iron (gray cast iron). The graphite flakes act as reflectors, what makes such measurements imprecise. The numerical results found are satisfactory in a qualitative way, but they disagree in the quantitative form. Shell models with theoretical imperfections also were created and analyzed using the finite element method in order to evaluate the behavior of the cylindrical shell under several configurations of distribution of the shell thickness variation. Further research is necessary on new technologies to measure the thickness of pieces manufactured of flake graphite cast iron. In this research, the oval shape measurements were done by means of eddy-current proximity sensors.
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FERREIRA, Bruna Cáritas Souza do Valle. "Uso de hidrolisado proteico de peixe e floco microbiano em substituição a farinha de peixe na alimentação de pós-larvas do camarão marinho Litopenaeus vannamei (Boone, 1931)." Universidade Federal Rural de Pernambuco, 2013. http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/6243.
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Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq
The present study aimed to evaluate the effect of replacing fishmeal for hydrolysate fish protein (HFP) and biofloc flour (BF) in diet of marine shrimp Litopenaeus vannamei postlarvae (2mg). The present study aimed to evaluate the effect of replacing fishmeal for hydrolyzed fish protein (HFP) and biofloc flour (BF) in Litopenaeus vannamei postlarvae. The HFP used in the diets formulation were produced from fish industry waste and the biofloc used for BF production was obtained in cultivation tanks of a commercial shrimp farm. Feed for this phase was designed to be isoenergetic and isoproteic. This experiment consisted of six treatments with three replicates each, corresponding to the control treatment T0, using fish meal as the main protein source. The other treatments (T10, T20, T30, T40) were a gradual replacement of fishmeal by HFP and BF in the proportions of 10, 20, 30 and 40% respectively. In the experiment a commercial feed was used as external control. It was a 42 days assay. Shrimp survival was above 99% in all treatments. After statistical analysis to zootechnical parameters (final weight, weight gain, specific growth rate) shrimps fed with formulated diets had better results than the ones fed with commercial feed. Tested parameters had ideal points indicated by regression in levels ranging between 15 and 16% of fishmeal replacement by HFP and associated BF. In the present study we inferred that BF and HFP are potential ingredients to replace fish meal in diets for L. vannamei postlarvae.
A presente dissertação teve como objetivo avaliar o efeito da substituição da farinha de peixe por hidrolisado proteico de peixe (HPP) e farinha de biofloco (FB) na alimentação de pós-larvas (2mg) do marinho camarão Litopenaeus vannamei. O HPP utilizado na elaboração das rações foi produzido a partir de resíduos de uma indústria de pescado. O biofloco para a produção da farinha foi obtido em tanques de cultivo de uma carcinicultura comercial. As rações para esta fase foram elaboradas para serem isoproteicas e isoenergéticas. Este experimento consistiu de seis tratamentos com três repetições cada, correspondendo ao tratamento controle o T0, utilizando a farinha de peixe como principal fonte proteica, e os demais tratamentos com substituição gradual da farinha de peixe por HPP e FB nas proporções de 10, 20, 30 e 40% correspondendo aos tratamentos T10, T20, T30 e T40 respectivamente. No experimento foi utilizado um tratamento com ração comercial que serviu como controle externo. Este ensaio teve duração de 42 dias. A sobrevivência dos camarões cultivados ficou acima de 99% em todos os tratamentos. As respostas estatísticas para os parâmetros de desempenho zootécnico (peso final, ganho de peso, taxa de crescimento específico) indicaram melhores resultados para os camarões alimentados com as rações formuladas quando comparados com os camarões alimentados com ração comercial. Os parâmetros testados tiveram seus pontos ideais indicados pela regressão, em níveis que variaram entre 15 e 16% de substituição da farinha de peixe por HPP e FB associados. Os resultados encontrados neste experimento indicaram o potencial dos ingredientes testados na substituição da farinha de peixe em rações para L. vannamei.
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Sjögren, Torsten. "Influences of the Graphite Phase on Elastic and Plastic Deformation Behaviour of Cast Irons." Doctoral thesis, Linköpings universitet, Konstruktionsmaterial, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-8776.
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The amount and morphology of the graphite phase largely controls the resulting properties of cast iron. For instance, in flake graphite cast irons the mechanical properties are low while the thermal conductivity is high. This is in contrast with spheroidal graphite cast irons where the mechanical properties are high and the thermal conductivity is low. These differences are due to the different graphite morphologies and must be accounted for in the design work and material selection of cast iron components. In this work the influence of the graphite phase on the elastic and plastic deformation behaviour of cast irons has been studied. The material grades studied originate from castings for marine diesel engine piston rings with different chemical analyses. Two groups of pearlitic cast iron materials were studied; one with differences in graphite morphology and one with grey irons that differed in graphite content. For these different material grades the mechanical properties were correlated to microstructural parameters. In addition to standard uniaxial tensile tests, acoustic emission measurements were used for the study of deformation. When studying the modulus of elasticity of the cast iron it was found that the modulus of elasticity of the inherent graphite phase depends on the roundness of the graphite particles and is due to the strong anisotropy of the graphite phase. A linear correlation between nodularity and the modulus of elasticity of the graphite phase was derived. This correlation made it possible to account for the anisotropy of the graphite phase in the model used. By applying the linear function when modelling the effective modulus of elasticity, a high accuracy between experimental and theoretical values was achieved. Another factor affecting the elastic response when subjecting a cast iron component to tensile load was found to be the plastic deformation that actually occurs at very low strains for all of the studied cast iron grades. It was observed that the plastic deformation in the low strain elastic region, quantified by using acoustic emission measurements, increased linearly with decreasing modulus of elasticity. These measurements showed that the amount of plastic deformation in the elastic region was largely controlled by the graphite morphology. It was concluded that as the roundness of the graphite particles increases, the plastic deformation activity in the elastic region decreases. The plastic deformation activity continued linearly into the pronounced plastic region of the tensile tests. A decrease in roundness or increase in graphite fraction resulted in an increase of the amount of plastic deformation and the strain hardening exponent. A dependence between strength coefficient and graphite fraction was observed. Models for the flow curves for pearlitic cast irons were developed and shown to accurately reproduce the observed experimental curves. The surveys performed and conclusions from this thesis will be helpful in the design of new cast iron materials.
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Beck, Sílvio Maurício. "EFEITOS NAS PROPRIEDADES MECÂNICAS, ELÁSTICAS E DE DEFORMAÇÃO EM CONCRETOS COM ALTOS TEORES DE ESCÓRIA E CINZA VOLANTE." Universidade Federal de Santa Maria, 2009. http://repositorio.ufsm.br/handle/1/7721.
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The use of byproducts and industrial waste as pozzolanic, is an alternative to achieve the sustainability, economy and durability in concrete structures. This survey has as its purpose to analyze the effect on mechanical, elastic and deformation properties on concrete with a high level of granulated slag from blast furnace and fly ash in place of Portland bulk cement. The use of high levels of mineral additions has the purpose of increasing the durability and
reducing the consumption of cement, the use of hydrated lime aims to activating these adittions, restore part of the calcium hydroxide consumed by the pozzolanic reactions, increasing the initial and final strength to the mixtures. This way, three mixtures of concrete have been studied: one of them without mineral additions, only using Portland cement (CP V-ARI), taken as a control, with relations a/c 0.40, 0.60 and 0.83, and two mixtures with mineral additions in place of cement in equal mass, with 70% of slag and 20% of fly ash, being one of them with addition of 20% of hydrated lime on the mass of binders in addition to the cement, both to the relations a/mc 0.30/0.33, 0.40 and 0.49, which have been renamed as R, EV and EVC. Tests were held to resistance to axial compression in bodies of evidence (10x20cm) the ages of 07 28, 91 and 300 days, whose results range from 18.2 MPa and 81 MPa, tests of resistance to traction by diametral compression and module of elasticity at 28, 91 and 300
days, as well as tests of total shrinkage on prismatic bodies of evidence (10x10x30 cm) at 28, 91, 180 and 300 days. The results of mechanical, elastic and strain resistance have been also correlated with some intervening and independent variables, as well as some existing
regulatory requirements. The results have been analyzed to each trace individually, in relation to the control traces, in relation to the evolution of the resistance, effectiveness of the use of the hydrated lime and in equal relationship a/mc 0.4. In the analysis of the equal relationship a/mc 0.400, in the case of reference concrete, in the initial age, the resistance to the
axial compression of the concrete EV was, in media, 72% of the one presented by it, being the resistance to the EVC 55%, and in the final age, 65% and 50% respectively. In the case of the traction by diametral compression, to 28 days the concrete EV presented 76% of the resistance of the reference, and the concrete EVC 58%. This relation to 300 days was 80% and 61% respectively. To the elasticity module, to 28 days, the concrete EV presented 82%
and the EVC 70% of the result obtained by the reference mixture, maintaining this proportion until the final age (300 days). In the analysis of the total retraction, the concrete EV presented an inferior retraction 10% inferior to the reference trace, while the concrete EVC to
300 days presents a good retraction 16% superior to it. The observation through the conjuncture of the results found shows a satisfactory relation among the different traces studied, making feasible the use of high levels of mineral additions in substitution to the large portion
of cement in bulk.A utilização de subprodutos e resíduos industriais como pozolanas, é uma alternativa para atingir a sustentabilidade, economia e durabilidade em estruturas de concreto. Esta pesquisa possui o objetivo de analisar os efeitos nas propriedades mecânicas, elásticas e de deformação em concretos com elevados teores de escória granulada de alto-forno e cinza volante em substituição ao cimento Portland em massa. O uso de altos teores de adições minerais tem por fim o aumento da durabilidade e redução do consumo de cimento, tendo o uso de cal hidratada a finalidade de ativar estas adições, repor parte do hidróxido de cálcio consumido pelas reações pozolânicas, aumentando as resistências iniciais e finais das misturas. Desta forma, estudaram-se três misturas de concreto: uma sem adições minerais, somente com cimento Portland (CP V-ARI), tomada como referência, com relações a/c 0.40, 0.60 e 0.83, e duas misturas com adições minerais em substituição ao cimento em igual massa, com 70% de escória e 20% de cinza volante, sendo uma delas com adição de 20% de cal hidratada em relação á massa de aglomerantes em adição ao cimento, ambas para relações a/mc 0.30/0.33, 0.40 e 0.49, as quais foram renomeadas como R, EV e EVC. Foram realizados ensaios de resistência a compressão axial em corpos de prova (10x20 cm) nas idades de 07, 28, 91 e 300 dias, cujos resultados variaram entre 18.2 MPa e 81 MPa, ensaios de resistência a tração por compressão diametral e módulo de elasticidade aos 28, 91 e 300 dias, assim como ensaios de retração total em corpos de prova prismáticos (10x10x30 cm) aos 28, 91, 180 e 300 dias. Também se correlacionou os resultados das resistências mecânicas, elásticas e de deformação com algumas variáveis intervenientes e independentes apresentadas, assim como com algumas prescrições normativas existentes. Os resultados foram analisados para cada traço individualmente, em relação aos traços referências, em relação à evolução da resistência, eficiência do uso da cal hidratada e em igualdade de relação a/mc 0.4. Na análise de igualdade de relação a/mc 0.400, em relação ao concreto referência, na idade inicial, a resistência a compressão axial do concreto EV foi, em média, 72% da apresentada por este, sendo a resistência do EVC 55%, e na idade final, 65% e 50%, respectivamente. Em relação à resistência a tração por compressão diametral, aos 28 dias o concreto EV apresentava 76% da resistência do referência, e o concreto EVC 58%. Esta relação, aos 300 dias foi de 80% e 61% respectivamente. Para o módulo de elasticidade, aos 28 dias, o concreto EV apresentou 82% e o EVC 70% do resultado obtido pela mistura referência, mantendo-se esta proporção até a idade final (300 dias). Na análise da retração total, o concreto EV apresentou uma retração 10% inferior ao traço referência, enquanto o concreto EVC aos 300 dias apresentou uma retração 16% superior ao mesmo. A observação através da conjuntura dos resultados obtidos demonstra uma satisfatória relação entre os diferentes traços estudados, viabilizando o uso de elevados teores de adições minerais em substituição a grande parcela de cimento em massa.
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Ojanne, Kim, and Errol Ljunghorn. "Att rädda ett företag." Thesis, Södertörn University College, School of Business Studies, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:sh:diva-1559.
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Denna uppsats är en fallstudie av företaget Svenskt Rekonstruktionskapital AB (SRK). Uppsatsens syfte är att försöka klargöra hur företaget SRK går tillväga vid en företagsrekonstruktion och belysa hur avkastningen på investerat kapital kan förändras med en ändrad kapitalstruktur. Fallstudien består av en metodtriangulering där en intervju genomfördes med företagets VD samt att årsredovisningar och informationsmaterial granskades. För att kunna uppfylla syftet med uppsatsen formulerades en frågeställning och för att kunna besvara frågeställningen togs en teoretisk grund fram där element som företagsvärdering, kapitalstruktur samt juridiska aspekter behandlas. Uppsatsens kom fram till att en ökad belåningsgrad är nödvändig om SRK vill öka avkastningen på eget kapital. Detta bör genomföras när SRK kan uppvisa nettooperativa vinstmarginaler. Vidare kom uppsatsen fram till att en viktig del av rekonstruktionsförfarandet är att säkra ett ackord. Detta eftersom ackordet förbättrar investeringen avsevärt. Dessutom konstaterar uppsatsen att en företagsrekonstruktion är beroende av många juridiska aspekter och att många olika instanser är inblandade i rekonstruktionsprocessen.
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Shen, Zhengyan. "Elaboration, caractérisation et nouvelle architecture de matériaux composites Al/plaquettes de carbone pour des applications thermiques." Thesis, Bordeaux, 2020. http://www.theses.fr/2020BORD0268.
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Dans l'industrie microélectronique, l'augmentation constante de la densité de puissance due à la miniaturisation des composants électroniques nécessite un matériau de dissipation thermique ayant une conductivité thermique élevée (CT), un faible coefficient de dilatation thermique (CTE) et des propriétés mécaniques (PM) appropriées pour une dissipation efficace de la chaleur. Des métaux purs, tels que Al et Cu, ont déjà été utilisés. Cependant, ils ont des CT limitées (ex. 240 W/m.K pour Al) et leurs CTE sont trop élevés (ex. 23 10-6/K pour Al), ce qui est incompatible avec ceux des composants électroniques (ex. 4 10-6/K pour Si), conduisant à une défaillance en service due à la fatigue thermique. À cet égard, les composites à matrice métallique se sont révélés être un matériau prometteur. Les matériaux en carbone, comme le graphite, le diamant et la fibre de carbone, ayant été introduits comme renforts en raison de leurs excellentes propriétés thermiques (c'est-à-dire un CT très élevé et un faible CTE) dans une matrice Al. Dans ces travaux de thèse, des matériaux composites à matrice en Al renforcé par des plaquettes de graphite peu coûteuses et facilement usinables (ci-après appelé composite Al/Gf) ont été développés dans le but de maximiser le CT, d'adapter le CTE proche de 6 10-6/K, ainsi que d'améliorer les PM.La CT intrinsèque du Gf est hautement anisotrope, c'est-à-dire 1000 W/m.K dans le plan et 5-10 W/m.K hors du plan. Il est donc clair que la bonne orientation de Gf dans la matrice d'Al assure un CT élevée, dans la direction du plan du graphite, ainsi qu’à l’échelle du matériau produit dans cette même direction. Dans cette étude, un procédé de remplissage des poudres étape par étape, a été appliquée avec succès afin d’obtenir cet arrangement 1D conventionnel. Ainsi, les valeurs de CT théoriques prévues les plus élevées peuvent être atteintes expérimentalement. En outre, les matériaux composites 2D et 3D de Gf ont été élaborés à l'aide de pistons spécialement conçus afin d'adapter le CTE anisotrope des Gf (c'est-à-dire -1 10-6/K dans le plan et 28 10-6/K hors plan). La structure 2D permet de réduire la CTE, qui est alors compatible avec celui du matériau du substrat (voisin de 8 10-6/K), tout en maintenant une CT élevée. Enfin, les efforts ont été consacrés à renforcer la matrice Al en intégrant des nanoparticules dispersées (ex-situ) de SiC et (in-situ) de TiB2 pour améliorer les PM globales du composite Al/GfIn the microelectronic industry, the ever increase in power density due to miniaturization of electronic components requires heat sink materials with a high thermal conductivity (TC), a low coefficient of thermal expansion (CTE), and specific mechanical properties (MP). Pure metals, such as Al and Cu, have been previously used. However, they have limited TCs (e.g. 240 W/m.K for Al) and their CTEs are too high (e.g. 23 × 10-6/K for Al), being incompatible with those of electronic components (e.g. 4 × 10-6/K for Si), leading to failures in service due to thermal fatigue. Regarding this, metal matrix composites have been proven to be promising material where carbon materials, such as graphite, diamond, and carbon fibres, have been introduced as reinforcements because of their excellent thermal properties (i.e. very high TC and low CTE). In this Ph.D. project, Al matrix composites reinforced with low-cost and easily machinable graphite flakes (hereafter called Al/Gf composite) were developed with the aim to maximize TCs, tailor CTEs close to 6×10-6/K, as well as improve MPs.The intrinsic TCs of Gf are highly anisotropic, i.e. in-plane TC of 1000 W/m.K and out-of-plane TC of 5-10 W/m.K, respectively. It is thus clear that the strong orientation of Gf in the Al matrix ensures the high TCs, along the direction of graphite plane, in the as-produced composite. In this study, a new approach to combining flake powder metallurgy with a step-by-step powder filling process was successfully applied to achieve this conventional 1D arrangement. As such, the highest TC values theoretically predicted can be achieved experimentally. Further, the 2D and 3D arrangements of Gf were made using specifically designed punches in order to tailor the anisotropic CTEs of Gf (i.e. in-plane CTE of -1 × 10−6/K and out-of-plane CTE of 28 × 10−6/K), being unavailable in the 1D arrangement. The 2D arrangement allows to achieve the reduced CTEs being compatible with those of the substrate materials while maintaining a high TCs, demonstrating the strong potential for applications. Finally, the efforts were devoted to strengthen the Al matrix by integrating dispersed (ex-situ) SiC and (in-situ) TiB2 nanoparticles to improve the overall MPs of the Al/Gf composites
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Abu, Khait Yosef. "Přetavení povrchu litiny s lupínkovým grafitem a možnosti jeho legování metodou elektronového paprsku." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2018. http://www.nusl.cz/ntk/nusl-377870.
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In this thesis, the structural and mechanical changes, which took place in flake graphite cast iron after electron beam surface melting and chrome-nickel surface alloying, were studied. Furthermore, the effect of set parameters on properties and depth of the melted and alloyed region is also analyzed. In the experimental part, the analyzed microstructures, micro-hardness and the distribution of elements after melting and alloying, were presented. Structural differences of material regions caused by melting were described based on microstructures. In the end of diploma thesis, the conclusions of using EB technology for surface melting and alloying were discussed.
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Tadesse, Abel. "On the Volume Changes during the Solidification of Cast Irons and Peritectic Steels." Doctoral thesis, KTH, Metallernas gjutning, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-202558.
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This thesis work deals with the volume changes during the solidification of cast irons and peritectic steels. The volume changes in casting metals are related to the expansion and/or contraction of the molten metal during solidification. Often, different types of shrinkage, namely macro- and micro-shrinkage, affect the casting quality. In addition to that, exposure of the metal casting to higher contraction or expansion during the solidification might also be related to internal strain development in samples, which eventually leads to surface crack propagation in some types of steel alloys during continuous casting. In consequence, a deep understanding of the mechanisms and control of the solidification will improve casting quality and production. All of the experiments during the entire work were carried out on laboratory scale samples. Displacement changes during solidification were measured with the help of a Linear Variable Displacement Transformer (LVDT). All of the LVDT experiments were performed on samples inside a sand mould. Simultaneously, the cooling curves of the respective samples during solidification were recorded with a thermocouple. By combining the displacement and cooling curves, the volume changes was evaluated and later used to explain the influence of inoculants, carbon and cooling rates on volume shrinkages of the casting. Hypoeutectic grey cast iron (GCI) and nodular cast iron (NCI) with hypo-, hyper- and eutectic carbon compositions were considered in the experiments from cast iron group. High nickel alloy steel (Sandvik Sanbar 64) was also used from peritectic steel type. These materials were melted inside an induction furnace and treated with different types of inoculants before and during pouring in order to modify the composition. Samples that were taken from the LVDT experiments were investigated using a number of different methods in order to support the observations from the displacement measurements: Differential Thermal Analysis (DTA), to evaluate the different phase present; Dilatometry, to see the effect of cooling rates on contraction for the various types of alloys; metallographic studies with optical microscopy; Backscattered electrons (BSE) analysis on SEM S-3700N, to investigate the different types of oxide and sulphide nuclei; and bulk density measurements by applying Archimedes' principle. Furthermore, the experimental volume expansion during solidification was compared with the theoretically calculated values for GCI and NCI. It was found that the casting shows hardly any shrinkage during early solidification in GCI, but in the eutectic region the casting expands until the end of solidification. The measured and the calculated volume changes are close to one another, but the former shows more expansion. The addition of MBZCAS (Si, Ca, Zr, Ba, Mn and Al) promotes more flake graphite, and ASSC (Si, Ca, Sr and Al) does not increase the number of eutectic cells by much. In addition to that, it lowers the primary austenite fraction, promotes more eutectic growth and decreases undercooled graphite and secondary dendritic arm spacing (SDAS). As a result, the volume expansion changes in the eutectic region. The expansion during the eutectic growth increase with an increase in the inoculant weight percentage. At the same time, the eutectic cells become smaller and increase in number. The effect of the inoculant and the superheat temperature shows a variation in the degree of expansion/contraction and the cooling rates for the experiments. Effective inoculation tends to homogenize the eutectic structure, reducing the undercooled and interdendritic graphite throughout the structure. In NCI experiments, it was found that the samples showed no expansion in the transversal direction due to higher micro-shrinkages in the centre, whereas in the longitudinal direction the samples shows expansion until solidification was complete. The theoretical and measured volume changes agreed with each other. The austenite fraction and number of micro-shrinkage pores decreased with increase in carbon content. The nodule count and distribution changes with carbon content. The thermal contraction of NCI is not influenced by the variation in carbon content at lower cooling rates. The structural analysis and solidification simulation results for NCI show that the nodule size and count distribution along the cross-sections at various locations are different due to the variation in cooling rates and carbon concentration. Finer nodule graphite appears in the thinner sections and close to the mold walls. A coarser structure is distributed mostly in the last solidified location. The simulation result indicates that finer nodules are associated with higher cooling rate and a lower degree of microsegregation, whereas the coarser nodules are related to lower cooling rate and a higher degree of microsegregation. As a result, this structural variation influences the micro-shrinkage in different parts. The displacement change measurements show that the peritectic steel expands and/or contracts during the solidification. The primary austenite precipitation during the solidification in the metastable region is accompanied by gradual expansion on the casting sides. Primary δ-ferrite precipitation under stable phase diagram is complemented by a severe contraction during solidification. The microstructural analysis reveals that the only difference between the samples is grain refinement with Ti addition. Moreover, the severe contraction in solidification region might be the source for the crack formation due to strain development, and further theoretical analysis is required in the future to verify this observation.QC 20170228
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Turrisi, Rob, Joel J. Hillhouse, Kimberly Mallett, Jerod L. Stapleton, and June K. Robinson. "A Systematic Review of Intervention Efforts to Reduce Indoor Tanning." Digital Commons @ East Tennessee State University, 2012. https://dc.etsu.edu/etsu-works/31.
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This chapter reviews the literature examining interventions to reduce indoor tanning (IT). The first objective was to highlight programs that show promise for large scale dissemination. The second objective was to promote criteria and standards for future intervention research efforts. The scope of interest for this review includes universal (for everyone in the population), selective (for those in the population who are at a greater risk), and indicated (for those who already are experiencing conditions that identify them as at risk) programs. The evaluation of the interventions resulted in three levels of evidence: (1) most promising, (2) emerging, and (3) mixed. For an intervention to be considered “most promising”, it was required that ten criteria be met through examination of research findings in published reports consistent with Flay and colleagues (Prev Sci 6(3):151–175, 2005). Interventions that were classified as “emerging” met most of the criteria. Finally, interventions classified as “mixed” did not reach threshold on more than two criteria that were deemed critical. The results revealed that there was very limited research on IT interventions that meet all the evaluation criteria. Only one intervention approach met all of the criteria (Appearance Booklet) (Hillhouse and Turrisi, Behav Med 25(4):395–409, 2002; Hillhouse et al., Cancer 113(11):3257–3266, 2008). Although the number of published papers in the IT area has increased dramatically over the past decade, these efforts have yet to translate into rigorously conducted intervention trials. The review points to important issues that need to be addressed in future research on the prevention of IT. Keywords
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Chen, Tsung-Hao, and 陳宗豪. "Synthesis of nano-flaky α-Al2O3." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/65808292005790053333.
Full textAbstract:
碩士國立成功大學
資源工程學系碩博士班
96
Alumina exhibits superior properties, such as high melting point, wear resistance, thermal as well as electrical insulation, perfect mechanical strength and chemical stability. Therefore, flaky alumina powders are often used as reinforcements in various materials to form multi-functional composites because of its two-dimensional shape. In this study different amount of potassium sulfate were added into boehmite with 5mol%Fe3+ ions to prepare a single-crystal α- Al2O3 hexagonal flake with a diameter of about 200 nm after calcining at 1000℃. Codoping 1mol% Ti4+ ions could promote the shape anisotropy and the diameter growth to about 400 nm. Without the addition of potassium sulfate, transformation of boehmite to α-Al2O3 is via the γ→θ→δ→α-Al2O3 path. However the transformation path was changed to γ→α-Al2O3 with the addition of potassium sulfate. Only achieved 83% of α-Al2O3 phase transformation was obtained as the molar ratio of potassium sulfate to boehmite achieved four. Potassium sulfate suppressed γ-Al2O3 coarsening which hence inhibited γ→α-Al2O3 phase transformation and inhibited the γ-Al2O3 to reach the critical nuclei size of α-Al2O3. In addition, it was found that Ti4+ ions had a strong tendency to segregate onto the (004) phase of α-Al2O3,which enhanced α-Al2O3 anisotropic growth and increased the shape anisotropy of flaky α-Al2O3. The effect of the addition of potassium sulfate and Ti4+ ions on the Al2O3 phase and morphology were investigated using differential thermal analysis (DTA), X-ray diffraction (XRD), transmission electron microscopy (TEM), Energy Dispersive Spectrometer (EDS). It was found that the addition of potassium sulfate, Fe3+ ions and Ti4+ ions could effectively prevent from the occurrence of α-Al2O3 vermicular growth and promoted phase transformation of intermediate γ-Al2O3 to α-Al2O3, which helped the formation of flaky single-crystal α-Al2O3 growth mechanism of flaky α-Al2O3 was via the oriented attachment of needle-like α-Al2O3 using of potassium sulfate as a template.
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Lin, Chin-Ju, and 林芩如. "Preparation of Instant Flaky-Dispersed Egg Soup." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/10839044052091562971.
Full textAbstract:
碩士國立中興大學
動物科學系所
96
Life in our country is getting more and more rush in recent years. Variety kind of instant foods come with the tide of trend. In this study, we use high nutritional contented fresh eggs to produce the dried egg soup by freeze-drying technology. We investigated the effects of different methods to blend eggs and adding modified potato starch, leavening agent, and moisture on the appearance and water absorption of flaky-dispersed egg soup after rehydrated. The results reveal that our experimental products were close to the fresh egg soup. This product can be used to diverse the choice of instant food and enhance the health of consumers. These hand-blended eggs could produce more ideal flaky- dispersed egg soup in the appearance and significantly higher（p＜0.05）water absorption（295.0±7.5%）compared with juicer-blended（199.7±14.8%）. Addition of modified potato starch into the boiled water can improve the appearance of flaky-dispersed egg soup after rehydrated and also increase the water absorption significantly （p＜0.05）from 152.7±5.1% to 297.3±8.5%. The optimal amount of modified potato starch is 0.4% under boiled water. By adding 0.5% of baking powder into hand-blended eggs can also improve the appearance and have the highest water absorption（295.0±5.3%）of flaky-dispersed egg soup. The 5% addition of modified potato starch into hand-blended eggs increased the water absorption significantly（p＜0.05）. Moreover, combining water into the hand-blended eggs can improve the water absorption significantly（p＜0.05） from 167.3±8.7% to 329.0±3.6%, and the rehydrated appearance can be improved by adding 50% of water into han-blended egg. On the 5 months storage test, the moisture（1.75∼1.80%）, water activity（0.21∼0.22）, water absorption（297.3∼300.6％）, color and TBA value（4.60∼4.64 ppm） were no significant change during storage. Where only the VBN value show the trend of significantly increase（0.03∼0.96 mg%, p＜0.05）. Our results totally prove that this product could be used to diverse the choice of instant food and enhance the health of consumers.
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Charles, Albert Linton, and 邱亞伯. "The Roles of Wheat Starch Granules in the Preparation of Chinese-Style Flaky Snacks." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/32553660001208279865.
Full textAbstract:
碩士國立屏東科技大學
熱帶農業研究所
89
Starch was isolated from wheat flour using the Martin Process and was studied comparatively for their physicochemical properties and the functional properties in Chinese-style flaky snacks. Moisture sorption isotherms at different levels of water activity revealed that the intact samples adsorbed less amount of water as compared to the increasingly higher water content of the gelatinized starch granules. Scanning electron microscopy (SEM) studies confirmed the disrupted, absorbent microstructure in dried gelatinized starch powder, and intact surface of the isolated intact starch granules. Water mobility in intact and dried gelatinized starch was investigated by solid-state nuclear magnetic resonance (NMR). Different spin-spin relaxation time of two water components, i.e., mobile or free water and bound water were identified. Data revealed water mobility with relaxation times of 4.70 ppm and 4.66 ppm, for intact and gelatinized granules, respectively. X-ray and differential scanning calorimetry (DSC) curves revealed crystalline structural differences between the starches. A popular Taiwanese snack was prepared and subjected to force deformation tests, to study the functional roles of the intact starch granules. The effects of different flour gluten levels and the enzyme, endogenous transglutaminase, on texture development of the snack were investigated. Instron tests showed that at different levels of flour gluten, there was a significant difference in hardness and fracturability intensities. Transglutaminase crosslinking reactions in gluten-protein matrix were exhibited. We concluded that the role of the intact starch granules dispersed throughout the gluten matrix system, significantly increased the fracturability and acceptability of the flaky snack. Hence, as a result of the intact granular surface membrane, the hypothesis that the intact starch granules, functioning as a “water sink”, “filler” and “structure setter” in controlling the hardness and fracturability properties of the flaky snack, was confirmed.
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Wu, Tsung-Lin, and 吳宗霖. "Processing and Characterization of Graphite Nano-Flake Composites." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/15278761110844847463.
Full textAbstract:
博士逢甲大學
機械與航空工程研究所博士班
96
In this work, resin epoxy is served as matrix, while natural graphite is served as filling. The mechanical properties of resulting graphite composite are not that good as expected, comparing with pure resin. To improve such situation, processing techniques, such as intercalation and exfoliation, are employed to make natural graphite turn into exfoliated graphite(EG). Exfoliated graphite is partly composed by graphite nanosheets, which are the additives of first graphite nanosheet in this work. Three types of composites were made to represent for three levels of dispersed graphite nanosheets. The first was the impregnation of epoxy resin to the expanded graphite by resin transfer molding. No dispersion was applied, and the expanded graphite can retain its original shape. The second use a high-power sonication to break apart the expanded graphite. The thickness of the sonicated expanded graphite was reduced about 100 times. The third method was to use a three–roll mill of high-shear strain rate to separate the graphite nanosheets from the expanded graphite and to disperse them into the resin. The thickness range of the graphite nanosheets was 20~50 nm, about 100 times thinner than the sonicated ones. Compression, high-shear straining, impact, and Three Point Bending Tests were conducted. OM(optical microscope), SEM (scanning electron microscope) and other measure equipment are used to observe and analyze the characteristics of different graphite nanosheet composites. The influence of dispersion on the material behavior was studied. The result shows that the graphite nanosheet composite after three-roll mill has the best dispersing effect among all, and thus has the best mechanical properties.