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The unsettled objectSharek, Elizabeth January 2007 (has links)
The Unsettled Object is an installational art project that considers the instability of objects in regards to their assembly, classification, and presentation, underpinned by the context of the museum and supported by Michel Foucault’s notion of the classificatory grids he discusses in The Order of Things: an archaeology of the Human Sciences. (Foucault,1970) The artefacts are being fabricated as a response to the corporeal body-on-display; its surfaces, spaces and volumes. An underlying notion of temporality and mutability is indicated in the processes of making, the objects, material responsiveness and the devices employed in the presentation of the work.
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Pasta de gesso com incorporação de resíduo de gesso e aditivo retardador de pega / Gypsum plaster with gypsum residue incorporation and setting retardant additiveTrovão, Ana Paula Milagres 10 August 2012 (has links)
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Previous issue date: 2012-08-10 / The use of plaster in civil construction generates a large amount of waste, but it is a material that posses properties that makes it a highly competitive product. The main cause of the generation of this waste is the rapid hardening of the pastes. The incorporation of waste gypsum into the gypsum pastes results in an acceleration of the hardening process, which might increase the volume of residues generated. This dissertation aimed to develop procedure to incorporate the gypsum residue into plaster pastes without compromising the paste mechanical properties and, especially without accelerating its hardening process. Tests have been developed to evaluate the plaster pastes setting time, consistency, workability and temperature reading in the plaster pastes in the fresh state and evaluate the hardness and axial compressive strength in the hardened state. Tests results showed the viability of the incorporation of 5% gypsum waste in substitution of gypsum in the plaster paste when combined with borax retardant additive, which promoted extension of the workable time of the paste and an increase in the pastes mechanical properties / A utilização do gesso pela construção civil gera um grande volume de resíduos, no entanto é um material que apresenta propriedades que o torna altamente competitivo no mercado. A principal causa da geração desse resíduo é o rápido endurecimento das pastas. A incorporação de resíduo de gesso às pastas provoca a aceleração no processo de endurecimento, podendo aumentar ainda mais o volume de resíduos gerados. Essa dissertação teve como objetivo buscar a forma de incorporação do resíduo às pastas de gesso para revestimento de parede, sem comprometer suas propriedades mecânicas e principalmente não acelerar seu endurecimento. Foram realizados os ensaios de tempo de pega, consistência, consistência útil e leitura de temperatura nas pastas em seu estado fresco além dos ensaios de dureza e compressão axial destas no estado endurecido. Os ensaios apontaram a viabilidade da incorporação de 5% de resíduo de gesso em substituição do gesso quando associado ao aditivo retardador bórax, que promoveu ampliação do tempo de utilização da pasta e o aumento nas propriedades mecânicas ensaiadas
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Avaliação do desempenho de aglomerante a base de gesso com cimento portland de alto forno e silica ativa / Perfomance assessment of gypsum cement based rendering materials containing portland blast-furnce slag cement and condensed silica fumeDe Milito, Jose Antonio 02 July 2007 (has links)
Orientador: Gladis Camarini / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-09T18:12:28Z (GMT). No. of bitstreams: 1
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Previous issue date: 2007 / Resumo / Resumo: O gesso é um aglomerante que tem sido muito empregado em revestimento de paredes. Apresenta um bom desempenho, é econômico e de fácil aplicação, mas limitado ao uso interno devido a sua sensibilidade à água. Algumas tentativas têm sido realizadas para melhorar a sua utilização em ambientes sujeitos à umidade. Neste sentido, pesquisas avançam na tentativa de empregar diferentes adições como resinas epóxi, polímeros, cimentos, escórias, impermeabilizantes, entre outros. O objetivo desta tese foi avaliar o desempenho das misturas de gesso com cimento Portland de Alto Forno e sílica ativa nos revestimentos internos e externos sujeitos à umidade. Para isso verificaram-se as propriedades macroscópicas das misturas por meio de ensaios físicos, químicos, físico-químicos e também a avaliação microestrutural utilizando a microscopia eletrônica de varredura. As misturas foram aplicadas em revestimentos de painéis de alvenaria de blocos de concreto e observados visualmente por um período de cinco anos. Além da observação visual foi verificada a resistência de aderência das misturas aplicadas internamente e externamente. Dos resultados obtidos observou-se uma possível coexistência entre o gesso e o cimento e que a adição de sílica ativa na mistura reduz a formação de etringita, principalmente nos revestimentos externos, sujeitos à umidade. A adição de cimento Portland melhora na abrasão e perda de massa, mesmo em idades mais avançadas. Assim, devido ao elevado custo de algumas adições, e as dificuldades de trabalhar com outros tipos de adição na obra, a adição de cimento Portland e sílica ativa ao gesso permitem uma melhoria de resistência, obtendo um revestimento de baixo custo e de fácil manuseio. / Abstract / Abstract: Plaster of Paris is a binding material being used in masonry as a plaster finish coat. Despite being economical, having good performance as and ease with wich it is applied in building, its use is limited to indoors. Some attempts has been made to improve its performance in external environment. In that sense, researches advance in the attempt at using several admixtures like epoxy resins, polymers, cements slags, waterproofing materials among other things. The objective of this thesis is to assess the performance of certain mixtures of rendering material containing plaster of Paris, slag cement and condensed silica fume when applied in the internal and external plaster finish coat. The macroscopic properties of the mixtures were analyzed through physical and chemical tests and also in SEM. Mixtures were applied on coatings of brick and mortar and visually inspected within five years. Bond strengths of the mixtures were measured, both in internal and external walls. Results showed compatibility between plaster of Paris and slag cement and that presence of condensed silica fume in the mixture reduced the formation of etringite, especially in the external coatings. The addition of Portland blastfurnace slag cement reduced the abrasion and the loss of mass, even in older ages. Therefore, due to the high cost of some admixtures, and the difficulty in working with other kinds of admixtures in the construction sites, the mentioned additions to the plaster rendering allow a mechanical strength improvement, thus resulting in low cost and good workability of the plaster finish coat. / Doutorado / Edificações / Doutor em Engenharia Civil
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Tianjiu therapy for patients with chronic asthma : an evaluation of efficacy and exploration of the optimal treatment durationZhu, Libing, 朱麗冰 January 2014 (has links)
Although Tianjiu Therapy in Sanfu Days (三伏天灸) is extensively being used for the treatment of asthma in Mainland China, there is a lack of convincing evidence to support its efficacy to expand its clinical application into asthma treatment. This study incorporated two related studies, the first was a randomized, double-blind, placebo-controlled trial with an aim to evaluate the efficacy of Tianjiu Therapy in Sanfu Days for patients suffering from chronic asthma. The second was a self-control clinical efficacy observation study aiming to compare the efficacy of 2 courses Tianjiu Therapy with 1 course such treatment in order to find the optimal duration of Tianjiu Therapy.
In the first study, 323 patients with chronic asthma were randomly assigned to Tianjiu Therapy group (n=165), and placebo group (n=158). There was no significant difference in primary and secondary outcome as compared with placebo group at the end of 3rd treatment and four times follow ups. But sub-analysis of secondary outcome in four times follow ups showed that Tianjiu Therapy significantly reduced the proportion of participants who didn’t need medical treatment during asthma attack increased from 6% to 15% at 1st follow up and 0% to 7% at 3rd follow up (P<0.05). In addition, Tianjiu Therapy was significantly superior to placebo in reducing the percentage of participants who were susceptibly waken up by asthma symptoms from 27% to 14%, and the percentage of participants who had the symptom of running nose and sneezing before onset from 18% to 8% at 2nd follow up ( P<0.05). Improvements also occurred with treatment group, it reduced the proportion of participants who were spontaneous sweating at 3rd follow up (P<0.05).
In the second study, totally 102 patients received two courses of Tianjiu Therapy (3 sessions Tianjiu Therapy in a year constituted one course of treatment). After treatment, the number of symptoms which were associated with Chinese Medicine added by 1.38 points (95% CI, 0.25 to 2.51), 2.93±0.41 in the 1 course group and 4.31±0.41 in the 2 courses group (P<0.05). The number of days with asthma-related symptoms increased by 3.05 points (95% CI, 0.37 to 5.73), 1.98±0.96 in 1 course group and 5.03±0.96 in 2 courses group (P<0.05). But both 1 course and 2 courses Tianjiu Therapy as compared with baseline (didn’t receive Tianjiu Therapy at this time point) have a significant improvement in the most outcome measurements.
From study 1, it was found that Tianjiu Therapy significantly decreased the need for pharmaceuticals to control asthma and improved the quality of participants’ life after one course Tianjiu Therapy. Study 2 indicated that although 2 courses Tianjiu Therapy was not as effective as 1 course Tianjiu Therapy in the treatment of asthma, both 1 course and 2 courses Tianjiu Therapy provided a significant improvement as compared with baseline. It was still unknown the optimal duration of Tianjiu Therapy, so it was worth to conduct the third course or more Sanfutianjiu Thearpy in future. / published_or_final_version / Chinese Medicine / Master / Master of Philosophy
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Prehistoric Wall Decoration in the American Southwest: A Behavioral ApproachMeyers, Julia Isabell January 2007 (has links)
Major social and demographic changes occurred during the Pueblo IV Period (AD 1300-1600) in the American Southwest. Small scattered communities aggregated into large settlement centers with more complex social organization during this period. Mural paintings created at this time are dramatically different stylistically from murals created before the social and demographic shift. At Homol'ovi in northeastern Arizona, these mural changes were accompanied by changes in plastering behaviors, including the development of distinct pigment use patterns.The hypothesis of the present study is that the visual performance characteristics of Hopi wall decorations, such as pigment sources, wall plaster colors and mural painting motifs, were part of a complex communicative system that changed as social power relationships changed and new rituals were established to support and legitimize the new social organization.Using inexpensive optical plaster and mural analysis techniques and XRF analysis of pigment samples from the ancestral Hopi sites of Homol'ovi I, Homol'ovi II and Chevelon, this research demonstrates the significance of wall decorations as social and political indicators marking transitions that occurred during the Pueblo IV and contact periods.
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STRUCTURAL BEHAVIOUR OF PLASTERED STRAW BALE PANELS UNDER NON-UNIFORM LOADINGRakowski, Michael Robert 30 September 2010 (has links)
The search for more sustainable construction methods has created a renewed interest in straw bales technology. Straw bales are a composite material that is energy efficient and durable. Rectangular straw bales stacked in a running bond and plastered on the interior and exterior faces have adequate strength to resist typical loads found in two-storey structures.
The structural behaviour of a load-bearing plastered straw bale wall subject to uniform loading is well researched. However, door and window voids in the wall redistribute vertical load paths and produce areas of concentrated stress. This thesis describes experiments on small-scale plastered straw bale panels subjected to loading conditions that simulate the loading conditions experienced in areas around door and window voids.
Twenty-one specimens were tested under two main types of loading conditions. The specimens were rendered with lime-cement plaster, were one to three bales (0.33 m to 0.99 m) in height, and were either unreinforced, or contained metal diamond lath or chicken wire embedded within the plaster. The specimens were pin-supported at various centre-to-centre distances ranging from 200 mm to 500 mm and were loaded either uniformly or by a point load.
Two distinct types of failure were observed. Strut-and-tie models were developed to describe the structural behaviour of panels undergoing vertical cracking of the plaster skin at failure. Bearing models were developed to describe the structural behaviour of panels undergoing crushing of the plaster skin beneath the point of applied load. The models predicted the correct failure mode of 92% of the specimens and had an average ratio of experimental strength to theoretical strength of 0.95 with a standard deviation of 0.17.
The results show that the behaviour of plastered straw bale walls can be predicted using common methods of structural analysis. A parametric analysis of door and window voids within plastered straw bale walls is presented. / Thesis (Master, Civil Engineering) -- Queen's University, 2010-09-30 11:32:53.613
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Infiltration of wind-driven rainfall into plastered straw bale wallsChase, Matthew 20 August 2009 (has links)
The performance of plastered straw bale walls with respect to wind-driven rainfall was investigated in this thesis. The absorption coefficient, which describes the rate of water infiltration, was measured for 14 plaster types, twelve different earth plasters and cement and lime plasters. The absorption coefficient was measured during uptake of water from a free reservoir. The effective porosity of these plasters, which describes the moisture storage capacity and the degree of protection that a plaster offers to straw bales, was also determined by submersion in water. An analytical model employing the absorption coefficient, the effective porosity, and climatic data was used to predict and compare plaster performance and to demonstrate the usefulness of this type of data. Simulated wind-driven rainfall experiments were also conducted on two plaster types. The results indicate that the static test used to measure the absorption coefficient can reasonably be used to predict actual wind-driven rainfall infiltration.
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Infiltration of wind-driven rainfall into plastered straw bale wallsChase, Matthew 20 August 2009 (has links)
The performance of plastered straw bale walls with respect to wind-driven rainfall was investigated in this thesis. The absorption coefficient, which describes the rate of water infiltration, was measured for 14 plaster types, twelve different earth plasters and cement and lime plasters. The absorption coefficient was measured during uptake of water from a free reservoir. The effective porosity of these plasters, which describes the moisture storage capacity and the degree of protection that a plaster offers to straw bales, was also determined by submersion in water. An analytical model employing the absorption coefficient, the effective porosity, and climatic data was used to predict and compare plaster performance and to demonstrate the usefulness of this type of data. Simulated wind-driven rainfall experiments were also conducted on two plaster types. The results indicate that the static test used to measure the absorption coefficient can reasonably be used to predict actual wind-driven rainfall infiltration.
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Archaeometrical Investigation Of Some Seljuk PlastersCaner, Evin 01 January 2003 (has links) (PDF)
The aim of the study was to investigate Seljuk Plasters used in some of their
royal administrative or residential buildings from a viewpoint of their raw
materials and technological characteristics. Some Byzantine Plasters of the
same period were also investigated to make comparison. Plasters from some
historic structures in the archaeological sites namely / Alanya Castle,
Kubadabad Palaces, Syedra Archaeological Site, Aspendos Amphitheatre,
Selinus Archaeological Site-Sekerhane Kö / sk and Hasbahç / e were examined.
In a series of examination basic physical properties of the plasters as bulk
density, porosity, water absorption capacity and water vapour permeability
were obtained. The results indicated that plasters are low dense and high
porous materials and having good breathing property.
Mechanical properties of the plasters were expressed by the modulus of
elasticity (Emod) values which were obtained from ultrasonic pulse velocity
measurements. The Emod of the plasters being in the range of 1.0 to 5.6 Gpa show that they have enough mechanical strength comparable to historic
mortars and bricks.
Raw material composition and mineralogical properties of plasters were
determined by combined interpretation of several types of analyses such as
chemical analyses, particle size distribution of aggregates, petrographic
analyses of thin sections by optical microscopy, scanning electron microscopic
analyses of cross sections coupled with EDX for image analyses and semiquantitative
elemental analyses, X-ray powder diffraction analyses for the
determination of mineral phases, thermogravimetric analyses and FTIR
analyses. Binder used in all plasters was found to be lime with amount in the
range of 53.8-96.8% as CaCO3. The main minerals of aggregates are quartz,
calcite (limestone), dolomite and opal-A. Regarding particle size distribution of
aggregates it was possible to classify them into fine, coarse and mixed
aggregates having rather high pozzolanicity.
Study on decorative and red zigzag patterned plasters indicated presence of
haematite as the source of red pigment. Study on green colored plaster also
indicated presence of iron containing mineral with lower oxidation state.
The Seljuk and Byzantine Masonries chosen are still surviving buildings that
their plasters should be of good quality. In fact, this study approved their
quality which may be due to the presence of opal-A and dolomite.
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Vergleichende Untersuchungen über die Volumenbeständigkeit einiger Abdruckgipsmischungen unter besonderer Berücksichtigung der abkochbarenHaas, Carl, January 1931 (has links)
Thesis (Doctoral)--Universität Göttigen, 1931.
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