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Pašto ženklų pažinimas X- XII klasėse per istorijos pamokas kaip komunikacinių mokinių gebėjimų ugdymo prielaida / Introduction of postage-stamps in history lessons for 10-12 classes as the presumption of development of student communicative abilitiesDunderis, Vilmantas 20 August 2006 (has links)
One of the aims of Lithuanian schools is to develop the pupil‘s perception of their aethetic abilities. Negative cultural phenomena have some influence on the communication in the sphere of art. Stamps can help to avoid negative aspects. It is very important in the 10th – 12th forms, because the teenagers are very receptive to different crises. Collecting stamps is an activity based on the communication which can broaden the knowledge of the art.
First stamps were published in 1840, and were quickly used in all over the world. The stamps became the representatives of the country, and its history, culture. The stamps are created by well – know artits, and are considered as the works of applied graphics.
The basic aspect of the communication for teenagers is to create their own identity and to find what they are really like. In due course, the communication with others became the main task for the teenagers, because the ability to associate with others allows to feel the sense of the maturity. The interest in stamps is a good way to expand the communication among teenagers.
Both, the teachers from Lithuania and from other countries wrote about the use of visual aids at the history lessons. All the authors stress the importance of the visual aids. The post stamps may be considered as pictures of applied works having the principle of the visual art. The principle of the visualizations is advisedto combine with the principle of the activity it... [to full text]
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Postage stamp recognition using image processingLi, Guancong January 2011 (has links)
Postage stamp is widely consumed in our daily life. In most of the cases, citizens need to purchase stamps in the post office or the local shop and may even need to wait in a long queue. This paper provides a stamp recognition system for supporting auto postage stamp selling machine, in order to convenient citizens and save labor cost for shops. Both citizens and stamp collectors can benefit from this system. This recognition system uses image processing is programmed using MATLAB®. Having scanned different pieces of postage stamps, our system could detect and recognize which type each piece of postage stamp belongs to. Besides, the coordinate information of each piece of stamp can be accessed for localization.
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Os “pequenos notáveis”: a utilização do selo postal no processo de ensino-aprendizagem da geografiaFiegenbaum, Maicon January 2017 (has links)
Selo postal: um artefato com um duplo papel comunicacional. De um lado, comunica legitimando a circulação de correspondências. Por outro, comunica através de seus elementos imagético-verbais. Apesar dos inegáveis atrativos que os modernos meios de entretenimento proporcionam aos jovens, não se pode deixar de constatar que estes pequenos notáveis podem ser utilizados no ensino da Geografia. A pesquisa buscará responder a seguinte pergunta: os selos postais têm potencial para serem utilizados como material didático alternativo e enriquecedor ao ensino da Geografia, e como a utilização dos selos postais em sala de aula permitiria a construção do conhecimento geográfico? O texto referencia a historicidade do selo postal, estabelecendo a relação desta historicidade com a interpretação contextual do espaço geográfico. Aborda o selo postal como uma possibilidade metodológica para a construção do conhecimento em sala de aula, articulado a partir de seis conceitos estruturantes que serão discutidos teoricamente embasados em autores do ensino e do ensino da Geografia, visando esclarecer ao leitor as intersecções desta ferramenta – o selo postal – com a prática pedagógica em Geografia. As diversas imagens que extrapolam desta técnica comunicacional permitem que o professor faça uso para despertar o encantamento pelo estudo da paisagem. O texto reconhece não somente a relação da comunicação com a temporalidade como também a relação deste elemento comunicacional com o ensino da Geografia. O trabalho almeja possibilitar a construção de habilidades e competências fundamentais para a leitura de imagens, a partir da elaboração de propostas pedagógicas que articulem a utilização do selo postal e o insira no contexto de práticas pedagógicas em turmas do 6º ano do Ensino Fundamental. / Postage stamp: an artifact with a double communicational role. On the one hand, it communicates legitimizing the circulation of correspondence. On the other hand, it communicates through its imagery-verbal elements. In spite of the undeniable attractions that modern media offer to young people, one can not fail to notice that these little notables can be used in the teaching of Geography. The search will answer the following question: the postage stamps have the potential to be used as alternative and enriching teaching material to the teaching of Geography, and how would the use of postage stamps in the classroom allow the construction of geographical knowledge? The text references the historicity of the postage stamp, establishing the relationship of this historicity with contextual interpretation of geographical space. It addresses the postal stamp as a methodological possibility for the construction of knowledge in the classroom, articulated from six structuring concepts that will be discussed theoretically based on authors of the teaching and teaching of Geography, in order to clarify to the reader the intersections of this tool - the Postage stamp - with the pedagogical practice in Geography. The various images that extrapolate from this communicational technique allow the teacher to use it to awaken the enchantment by studying the landscape. The text recognizes not only the relationship of communication with temporality but also the relation of this communicational element to the teaching of Geography. The work aims to enable the construction of basic skills and competences for the reading of images, based on the elaboration of pedagogical proposals that articulate the use of the postage stamp and insert it in the context of pedagogical practices in classes of the 6th grade of Elementary School.
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Os “pequenos notáveis”: a utilização do selo postal no processo de ensino-aprendizagem da geografiaFiegenbaum, Maicon January 2017 (has links)
Selo postal: um artefato com um duplo papel comunicacional. De um lado, comunica legitimando a circulação de correspondências. Por outro, comunica através de seus elementos imagético-verbais. Apesar dos inegáveis atrativos que os modernos meios de entretenimento proporcionam aos jovens, não se pode deixar de constatar que estes pequenos notáveis podem ser utilizados no ensino da Geografia. A pesquisa buscará responder a seguinte pergunta: os selos postais têm potencial para serem utilizados como material didático alternativo e enriquecedor ao ensino da Geografia, e como a utilização dos selos postais em sala de aula permitiria a construção do conhecimento geográfico? O texto referencia a historicidade do selo postal, estabelecendo a relação desta historicidade com a interpretação contextual do espaço geográfico. Aborda o selo postal como uma possibilidade metodológica para a construção do conhecimento em sala de aula, articulado a partir de seis conceitos estruturantes que serão discutidos teoricamente embasados em autores do ensino e do ensino da Geografia, visando esclarecer ao leitor as intersecções desta ferramenta – o selo postal – com a prática pedagógica em Geografia. As diversas imagens que extrapolam desta técnica comunicacional permitem que o professor faça uso para despertar o encantamento pelo estudo da paisagem. O texto reconhece não somente a relação da comunicação com a temporalidade como também a relação deste elemento comunicacional com o ensino da Geografia. O trabalho almeja possibilitar a construção de habilidades e competências fundamentais para a leitura de imagens, a partir da elaboração de propostas pedagógicas que articulem a utilização do selo postal e o insira no contexto de práticas pedagógicas em turmas do 6º ano do Ensino Fundamental. / Postage stamp: an artifact with a double communicational role. On the one hand, it communicates legitimizing the circulation of correspondence. On the other hand, it communicates through its imagery-verbal elements. In spite of the undeniable attractions that modern media offer to young people, one can not fail to notice that these little notables can be used in the teaching of Geography. The search will answer the following question: the postage stamps have the potential to be used as alternative and enriching teaching material to the teaching of Geography, and how would the use of postage stamps in the classroom allow the construction of geographical knowledge? The text references the historicity of the postage stamp, establishing the relationship of this historicity with contextual interpretation of geographical space. It addresses the postal stamp as a methodological possibility for the construction of knowledge in the classroom, articulated from six structuring concepts that will be discussed theoretically based on authors of the teaching and teaching of Geography, in order to clarify to the reader the intersections of this tool - the Postage stamp - with the pedagogical practice in Geography. The various images that extrapolate from this communicational technique allow the teacher to use it to awaken the enchantment by studying the landscape. The text recognizes not only the relationship of communication with temporality but also the relation of this communicational element to the teaching of Geography. The work aims to enable the construction of basic skills and competences for the reading of images, based on the elaboration of pedagogical proposals that articulate the use of the postage stamp and insert it in the context of pedagogical practices in classes of the 6th grade of Elementary School.
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Os “pequenos notáveis”: a utilização do selo postal no processo de ensino-aprendizagem da geografiaFiegenbaum, Maicon January 2017 (has links)
Selo postal: um artefato com um duplo papel comunicacional. De um lado, comunica legitimando a circulação de correspondências. Por outro, comunica através de seus elementos imagético-verbais. Apesar dos inegáveis atrativos que os modernos meios de entretenimento proporcionam aos jovens, não se pode deixar de constatar que estes pequenos notáveis podem ser utilizados no ensino da Geografia. A pesquisa buscará responder a seguinte pergunta: os selos postais têm potencial para serem utilizados como material didático alternativo e enriquecedor ao ensino da Geografia, e como a utilização dos selos postais em sala de aula permitiria a construção do conhecimento geográfico? O texto referencia a historicidade do selo postal, estabelecendo a relação desta historicidade com a interpretação contextual do espaço geográfico. Aborda o selo postal como uma possibilidade metodológica para a construção do conhecimento em sala de aula, articulado a partir de seis conceitos estruturantes que serão discutidos teoricamente embasados em autores do ensino e do ensino da Geografia, visando esclarecer ao leitor as intersecções desta ferramenta – o selo postal – com a prática pedagógica em Geografia. As diversas imagens que extrapolam desta técnica comunicacional permitem que o professor faça uso para despertar o encantamento pelo estudo da paisagem. O texto reconhece não somente a relação da comunicação com a temporalidade como também a relação deste elemento comunicacional com o ensino da Geografia. O trabalho almeja possibilitar a construção de habilidades e competências fundamentais para a leitura de imagens, a partir da elaboração de propostas pedagógicas que articulem a utilização do selo postal e o insira no contexto de práticas pedagógicas em turmas do 6º ano do Ensino Fundamental. / Postage stamp: an artifact with a double communicational role. On the one hand, it communicates legitimizing the circulation of correspondence. On the other hand, it communicates through its imagery-verbal elements. In spite of the undeniable attractions that modern media offer to young people, one can not fail to notice that these little notables can be used in the teaching of Geography. The search will answer the following question: the postage stamps have the potential to be used as alternative and enriching teaching material to the teaching of Geography, and how would the use of postage stamps in the classroom allow the construction of geographical knowledge? The text references the historicity of the postage stamp, establishing the relationship of this historicity with contextual interpretation of geographical space. It addresses the postal stamp as a methodological possibility for the construction of knowledge in the classroom, articulated from six structuring concepts that will be discussed theoretically based on authors of the teaching and teaching of Geography, in order to clarify to the reader the intersections of this tool - the Postage stamp - with the pedagogical practice in Geography. The various images that extrapolate from this communicational technique allow the teacher to use it to awaken the enchantment by studying the landscape. The text recognizes not only the relationship of communication with temporality but also the relation of this communicational element to the teaching of Geography. The work aims to enable the construction of basic skills and competences for the reading of images, based on the elaboration of pedagogical proposals that articulate the use of the postage stamp and insert it in the context of pedagogical practices in classes of the 6th grade of Elementary School.
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La création artistique : le timbre-poste français gravé en taille-douce de 1928 à nos jours / Artistic creation : the French postage stamp engraved in intaglio from 1928 to the present dayNowacka, Monika 12 January 2017 (has links)
Nombreux sont les artistes plus ou moins reconnus qui travaillent pour le compte de l’administration postale depuis 1928, année d'émission du premier timbre-poste français gravé en taille-douce. Cette technique, devenue le procédé par excellence de création des timbres-poste en France, se développa et connut des temps forts avec les années 1930 et jusque dans les années 1970. Tous les timbres-poste, à quelques rares exceptions, sont alors gravés par des artistes. Peu à peu, l’apparition de nouveaux procédés de fabrication, tels que l’héliogravure, l’offset et la gravure assistée par ordinateur, s’impose à la taille-douce traditionnelle. Aussi, le poinçon, plaque en acier qui sert de support au graveur, est progressivement remplacé par des procédés électromécaniques et photochimiques permettant d’obtenir des délais d’exécution et des coûts de fabrication bien moindres et sans doute mieux adaptés à des productions industrielles. Cette étude présente une analyse de l’évolution de l’art de la gravure, de sa place et de son rôle dans le domaine de la philatélie durant une période précise, de 1928 à nos jours. Le statut de l’artiste graveur et sa reconnaissance artistique évoluent au même titre que changent le statut de l’administration postale, sa politique et ses besoins liés aux exigences économiques du marché. L’examen approfondi des créations philatéliques, commandes régies par un cahier des charges strict ainsi que des conditions de travail et de l’investissement des graveurs de timbres face à leur métier, a permis de présenter les particularités esthétiques et plastiques de leurs travaux et de leur attribuer une place dans le domaine de l’art. / Many artists, some more famous than others, have worked for the postal administration since 1928, the year of the first issue of an engraved French postage stamp . This technique, which became the most important method of creating postage stamps in France, developed and reached a peak in the 1930s and continued until the 1970s. During this time all postage stamps, with few exceptions, were engraved by artists. Gradually, however, the emergence of new manufacturing processes, such as heliogravure, offset printing and computer-aided engraving, replaced traditional engraving. Also, the stamping device, a steel plate that served as a support for the engraver, was gradually replaced by electromechanical and photochemical processes making it possible to obtain much lower turnaround times and manufacturing costs and was probably better suited to industrial production. This study presents an analysis of the development of the art of engraving, its place and its role in Philately during a specific period, from 1928 to the present day. The status of the engraver and his artistic recognition changed along with the status of the postal administration, its policy and its needs in response to the economic demands of the market. The in-depth review of philatelic creations, orders governed by strict specifications, working conditions and the investment of stamp engravers in their craft, has made it possible to show the aesthetic and plastic features of their work and secure them a place in the art world.
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La construction de l’identité canadienne à travers le paysage, le cas des timbres peints par Jean Paul LemieuxRobb, Dominique 05 1900 (has links)
Le présent mémoire a pour but de contextualiser et d’analyser Visions du Canada, une série de douze paysages représentant chaque province et territoire du pays. Commandés par la Société canadienne des postes en 1982 au peintre québécois Jean Paul Lemieux, ils sont émis en 1984 dans le cadre de Jour du Canada, une série annuelle visant à souligner la fierté et l’appartenance nationale lors de la fête du Canada. Les paysages variés et colorés d’apparence sereine, réalisés dans un style semi-classique, exhibent l’image d’un Canada uni, égalitaire et diversifié. Le contexte historique et politique dans lequel ils sont produits lève toutefois le voile sur une réalité plus complexe, puisque l’échec du référendum sur la souveraineté en 1980 et le mécontentement des Québécois face aux conditions du rapatriement de la Constitution en 1982 accentuent les clivages culturels entre le Québec et le reste du Canada. La nature présentée dans Visions du Canada est alors envisagée par le gouvernement fédéral comme la source de l’unité nationale. En commandant au peintre québécois des œuvres conçues pour être diffusées à l’échelle nationale, le gouvernement, par l’entremise de la Société canadienne des postes, brouille en fait les dichotomies entre l’identité québécoise et canadienne. Les fonctions intrinsèques du timbre permettent par la suite de rendre ce message accessible à tous les Canadiens. Ainsi, l’analyse des œuvres de Visions du Canada révèle une perception plus nuancée et plus complexe du paysage canadien. Les interrogations qui ponctuent la carrière de Lemieux, comme la relation entre l’Humain et l’univers et l’angoisse face à la modernisation, viennent également remettre en question les mythes de la coexistence avec la nature et de la nordicité qui affirment l’unité du pays. / The purpose of this thesis is to contextualize and analyse Visions du Canada, a series of twelve landscapes representing the country’s provinces and territories. Commissioned to Quebec painter Jean Paul Lemieux by the Canada Post Corporation in 1982, they are issued in 1984 as part of Canada Day, an annual series designed to highlight national pride and belonging on Canada Day. Created in a semi classic style, these varied, colourful, and serene-like landscapes display a united, equal and diverse image of Canada. However, the historical and political context in which they are produced reveals a more complex reality. Indeed, the failure of the 1980 referendum on sovereignty and the Quebecers’ dissatisfaction with the terms of the Constitution’s patriation in 1982 fuel the cultural divide between Quebec and the rest of Canada. In Visions du Canada nature creates the basis for national unity as envisioned by the federal government. By commissioning works designed for national dissemination to the Quebec painter, the government, through the Canada Post Corporation, thus blurs the dichotomy between Quebecer and Canadian identity. The stamp’s intrinsic functions then render this message accessible to all Canadians. Therefore, an analysis of Visions du Canada reveals a more nuanced and complex perception of the Canadian landscape. The questions that punctuate Lemieux’s career, such as the relationship between the human being and the universe and the anguish in front of modernization, also challenge the myths of coexistence with nature and northerness that sustain the country’s claim to unity.
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Utvärdering av den svenska gasmarknadsmodellenCederborg, Max, Heumann Bauer, Martin January 2013 (has links)
Denna rapport syftar till att utvärdera de för- och nackdelar den svenska gasmarknadsmodellen har relativt de shippermodeller som finns i Europa, där modellernas lämplighet att stimulera ökad konkurrens i synnerhet beaktas. Därtill behandlas de krav som nuvarande och kommande EU-lagstiftning ställer och vilka konsekvenser detta får för Sveriges del. Studien ska ge underlag för en bedömning om den svenska modellen är välfungerande eller om en förändring kan motiveras, och i så fall i vilken riktning. Till fördel för nuvarande svenska modell lyfts lättförståelighet och lägre motpartsrisk vid kapacitetsbokning fram. Även pristransparensen bedöms vara bättre till följd av att gas och transport faktureras separat. Transportkostnad fram till den svenska gränsen ingår likväl fortfarande i gaspriset. En shippermodell å andra sidan, bedöms skapa bättre förutsättningar för konkurrens och därmed öka incitamenten för utländska aktörer att ta sig in på den svenska marknaden. Dels ges aktörerna möjlighet att konkurrera om transport, dels skulle modellen överenstämma med de modeller utländska aktörer har på sina hemmamarknader. Många aktörer menar att den svenska modellen fungerar tillfredsställande i sin nuvarande utformning och att val av marknadsmodell inte är viktigast för utvecklandet av naturgasmarknaden. Mot bakgrund av detta samt de fördelar modellen har och den svenska marknadens ringa storlek, så framstår det som ett rimligt alternativ att behålla den. Vad gäller EU:s harmoniseringsarbete är det två nätkoder som i nuläget är mest aktuella, CMP och CAM, där CAM får konsekvenser för kapacitetsbokning i gränspunkter ellanentry/exit-zoner. Gränspunkten mellan Sverige och Danmark är i nuläget undantaget från CAM men åsikterna om huruvida detta är möjligt framöver eller inte går isär, ytterligare införselpunkter kan komma att skapa problem. Därtill vet vi inte i nuläget vilka konsekvenser kommande lagstiftning kan få för Sverige. Ett modellbyte kan således bli oundvikligt i slutändan. Vid ett byte är vår rekommendation är att undersöka möjligheten att övergå till en hel shippermodell, där både transmissions- och distributionsnät inkluderas i entry/exitzonen. Att ha en avvikande modell är tidskrävande, primärt för Energimarknadsinspektionen och Swedegas, till följd av EU:s harmoniseringsarbete som utarbetas för en shippermodell då detta är den vanligaste lösningen i Europa i allmänhet. Vi tror dessutom att en sådan lösning skulle gynna konkurrensen på marknaden, inte minst på hushållsmarknaden till följd av att kunden enbart får en kontaktpunkt oavsett om gasleverantör och distributionsbolag befinner sig inom samma koncern eller inte. / This report aims to evaluate the advantages and disadvantages of the Swedish gas market model in comparision to shipper models, which are common in the EU in general. The models’ suitability to stimulate competition is especially considered. In addition, the requirements of present and future EU legislation sets and the resulting consequences for Sweden are covered in the report. The study will provide a basis for assessing whether the Swedish model is well functioning or if a change is needed, and if so in which direction. Advantages of the Swedish model are that it is easy to understand and that it has a lower counterparty risk when it comes to capacity reservation. Also, the price transparency is considered to be better since the gas and transport charges are invoiced separately. Transportation cost to the Swedish border is nevertheless still included in the gas price. A shipper model on the other hand, is expected to create a more competitive market and to increase incentives for foreign players to enter it. The players are given the opportunity to compete for transportation and the model would also match the models foreign players face in their home markets, thus lowering the entry barriers. Many respondents think that the Swedish model works well in its present form and that the choice of market model is not of highest importance for the development of the natural gas market. In light of this, the benefits of the current model and the Swedish market's small size, it seems like a reasonable option to keep it. As for the EU harmonization, there are two network codes that are currently most relevant, CMP and CAM. The CAM network code has implications for capacity reservation in the cross-border points between different entry/exit-zones. The point between Sweden and Denmark is currently excluded from CAM, but opinions regarding whether this is possible in the future or not differ. Additional entry points might create problems. In addition, at this point we do not know what impact future legislation may have. A model change can thus be inevitable in the end. If changing, our recommendation is to investigate the possibility of switching to a full shipper model where both the transmission and distribution networks are included in the entry/exit-zone. Having a model that differs from the rest of EU is time consuming, primarily for EI and Swedegas, since the harmonization efforts made by the EU are tailored for a shipper model since this is the prevailing system in Europe in general. We also believe that such a solution would benefit market competition. This is particularly true for the residential market because the customer only gets one contact point, whether gas suppliers and distribution companies are in the same Group or not.
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Adhesion Studies of Polymers: (I) Autohesion of Ethylene/1-Octene Copolymers; (II) Method Development and Adhesive Characterization of Pressure Sensitive Adhesive in Paper Laminates for Postage StampsYang, Hailing 08 May 2006 (has links)
Autohesion is defined as the resistance to separation of two bonded identical films that have been joined together for a period of time under a given temperature and pressure. Studies on the autohesion phenomenon can provide fundamental insights into the physical processes of adhesive bond and failure, as well as the practical engineering issues such as crack healing, elastomer tack, polymer fusion, self-healing, and polymer welding. In the first part of this dissertation work, four ethylene/1-octene (EO) copolymers were used in the present study consisting of molecules with linear polyethylene backbone to which hexyl groups are attached at random intervals. These copolymers have similar number-average molecular weight (Mn) and polydispersity, but different 1-octene content. These hexyl groups act as the short branches and hinder the crystallization, reduce density to some extent in the solid state, lower the melting temperature, and decrease the stiffness of the bulk materials. A full understanding of the autohesion behavior of the ethylene/1-octene copolymers involves investigations at three different length scales: 1) the molecular scale which controls the interfacial structure; 2) the mesoscopic or microscopic scale which can provide information on the formation of interfaces and on how the energy is dissipated during a fracture process; and 3) the macroscopic scale at which the mechanical properties such as fracture energy can be obtained for a particular test geometry. In the present study, the effects of the branch content on the formation and fracture of the interface of these ethylene/1-octene assemblies were evaluated at the bonding temperatures (Tb) and bonding times (tb). The correlation among these three length scales was also investigated and modeled.
The adhesion strength of these symmetric interfaces of EO copolymers was investigated by T-peel fracture tests. The fracture of the interface is an irreversible entropy creating process which involved a substantial amount of energy dissipation. The results of such mechanical tests with respect to the bonding temperature (Tb), bonding time (tb) and peel rate indicated this energy dissipation is the result of a complicated interplay between the ability of the interface to transfer stress and its plastic and viscoelastic deformation properties. When Tb is much higher than the characteristic temperature (Tc), the interfaces were completely healed and cohesive failure was observed in T-peel tests. In this case, the fracture strength decreased with increasing branch content. In contrast, when Tb is very close to Tc, the fracture strength showed an increase with the branch content with either interfacial failure or cohesive failure being observed depending on the branch content and Tb. At higher peel rates, it is observed that higher peel energies are required to fracture the surfaces. Transmission electron microscopy (TEM) showed that the interfacial/interphase structure changed from amorphous to crystalline with an increase in the Tb.
The results from the bonding time effect studies showed that the peel energy is proportional to tb1/2 regardless of Tb. But the branch content and the Tb play an important role on the seal rate. Thus, higher seal rate was found for higher Tb and higher branch content. These results also suggest that the autohesion of ethylene/1-octene copolymers are strongly associated with the interactions of melted chains. The chain compositions of these Zeigler-Natta EO copolymers are highly heterogeneous with the branches concentrated in the lower molecular weight portion. Long linear chain segments could form large, well-ordered crystals that provide strong anchors for the tie molecules and therefore determine the density of inter-crystalline links. Short chains with lots of branches could behave as protrusions along the chain to obstruct chain disentanglement and limit a chain from sliding through a crystal. Due to these reasons, the short chains with branches would contribute much less than the long linear chains to the full peel strength after complete sealing. However, higher peel strengths could be obtained only at the higher temperatures or longer bonding times at which the long linear chains begin to melt and diffuse across the interface. On the other hand, the higher branch content samples have the lower crystallinity and could obtain the higher chain mobility at the lower bonding temperatures and with shorter bonding times. Therefore, higher seal strength was observed for the higher branch content samples at lower Tb.
Following T-peel fracture tests of ethylene/1-octene copolymer assemblies which showed interfacial failures, the fractured surfaces were investigated by using Atomic Force Microscopy (AFM) and characterized by fractal analysis together with the original films. The AFM images showed strong dependence on the peel rate and branch content. Quantitatively, the fractal analyses demonstrated fractal characteristics at the different finite scales. Two regimes showing fractal features were identified for each surface. In regime I (low magnifications) the fracture test did not change the fractal dimensions much. But there were significant changes in regime II before welding and after T-peel fracture tests. The length scale that separated these two regimes is very close to the size of lamellar structures. The characteristic sizes at which the fractal characteristics emerge were shown to appear at larger scales for surfaces fractured at higher peel rates. This suggests that the appearance of fractal behavior at larger scales requires higher fracture energies. The characteristic sizes and fractal dimensions were shown to depend on the molecular structure. Because the fractal analysis suggests at least some crystalline lamellae on the surfaces still existed during T-peel fracture tests, a "Stitch-welding" has been therefore proposed as the autohesion mechanism in which only chains in the amorphous portions could inter-diffuse.
In the second part of this dissertation work, a multi-layer lap-shear geometry has been designed and proven as a reliable testing method in evaluation of the dynamical mechanical properties of polyacrylic pressure sensitive adhesive (PSA) in paper lamination for postage stamp applications. In-situ testing of four different PSA stamp laminates constructed by laminating water-based polyacrylic PSAs to the stamp face papers were carried out using a dynamic mechanical analyzer (DMA) in the temperature range from -50 to 60 oC at frequencies 0.1, 1, 10, and 100 Hz. This geometry requires the tension mode on the DMA, but the results which were recorded as tensile properties were converted to shearing properties of the PSA layers in the laminate. The effect of the thickness (layers of laminates) on the dynamical mechanical properties has been studied and the results suggested that a multi-layer geometry with 5-10 layers could be an appropriate structure to produce enhanced responses. Therefore, the geometry with 8-layer laminates was used for frequency sweep/isothermal temperature and frequency sweep/temperature step tests. The results showed three relaxation responses that is, glassy, transition, and flow regions with respect to the frequencies and temperatures. These results also implied the viscoelastic characteristics of these PSA products. The tensile properties of the face papers were also tested using the same parameters as those of the multi-layer geometry. Significant differences were found between the shearing behaviors of the multi-layer geometry and the tensile behaviors of the elastic face paper. This suggests that the tensile deformation of the face paper in the multi-layer geometry could be ignored and the elastic paper did not contribute to the shearing properties of the PSA layers. Time-temperature superposition curves have been produced with reference temperature set at 23 oC, which can be used to predict the long term and short term performances of these samples at this temperature.
This method can be utilized as a standard testing method on the PSA adhesives in the laminate form. In addition to the dynamic mechanical properties, it can also be developed to be a general standard method on testing the rheological properties of adhesives, polymer melts and other viscous materials. / Ph. D.
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History Will Be My Judge: A Cultural Examination of America's Racial Tensions Presented Through the Symbolization of Booker T. WashingtonKeturah C Nix (8088539) 06 December 2019 (has links)
<i> History Will Be My Judge: A Cultural Examination of America's Racial Tensions Presented Through the Symbolization of Booker T. Washington</i> is an interdisciplinary study about the emergence of Booker T. Washington as a black cultural hero. By the turn of the twentieth century, Washington had become the most prominent African American educator, economic reformer, entrepreneur, and race leader in the United States. He is most recognized as the founder of Tuskegee Institute (now University) and his highly acclaimed autobiography, <i>Up From Slavery</i>, which recounts his life growing up enslaved to becoming an international icon. Since his death in 1915, several monuments, memorials, landmarks, and commemorative tributes have been established in his honor. During the 1940s, Washington became the first African American pictured on the United States postage stamp and minted silver half-dollar. Additionally, he was spotlighted in a series of media campaigns called "Famous American Firsts," and was the first African American inducted into the Hall of Fame for Great Americans. Moreover, amidst the presidential transition between Barack Obama and Donald Trump, black popular media has alluded to Washington's economic philosophy through music videos, documentaries, and television programs. I argue that each of these posthumous commemorations belong to larger social justice movements, namely, the Civil Rights movement and Black Lives Matter movement. Throughout these eras, Washington's legacy has served to counter white supremacy and symbolize the rise of integration, the black middle class, economic justice, black self-made, black education, and the legacy of slavery.<div> The purpose of this study is to examine how during periods of racial unrest, African Americans leverage Booker T. Washington's image to counter racist stereotypes and reaffirm black citizenship. The primary framework applied in this study is William L. Van Deburg's theory of the <i>black cultural hero. </i>Two emergent theories from this research are my developing frameworks called <i>Black Hustle Theory</i> and <i>nostalgic tension</i>. Using literary and visual analysis, I assess historical archives from popular press, black literature, American memorabilia, and black popular culture to examine Washington's commemorative legacy through a black radical lens. Specifically, I explore how the following four people have connected Washington's legacy to the Civil Rights movement and Black Lives Matter movement: Major Richard Robert Wright, Sr., founder of Savannah State University; Langston Hughes, famed Harlem Renaissance poet and author; Stanley Nelson, award-winning producer; and, Beyonce Knowles-Carter, singer and pop mogul. I put Washington's legacy in conversation with each of these cultural producers to simulate a call-and-response between his lifework and the generations after him.<br><div><br></div></div>
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