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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
191

Bradford Mills at Marki, Warsaw: A Case Study of British Entrepreneurship in Russian Poland 1883 – 1914

Dietz, Sarah January 2013 (has links)
This thesis explores the late-nineteenth century partnership between Bradford worsted manufacturers the Briggs brothers and the German merchant Ernst Posselt, and their subsequent foreign direct investment in a modern factory and workers’ community at Marki, near Warsaw, in Russian Poland. Protectionism and increasing foreign competition are discussed, among many complex economic pressures on British industry, as likely catalysts for this enterprise and the general historiography of the Polish lands is explored to reveal a climate of extraordinary opportunity for well-capitalised foreign industrialists in this period. This thesis provides fresh perspective on the role of the consular service in facilitating British foreign enterprise and, in context of the Bradford partners’ strategy for local integration through social networking and religious affiliation, presents unique findings regarding the character and operations of Warsaw’s elite commercial community in the late-nineteenth century. Through the development and domination of market and raw materials sources, this venture is shown to have monopolised worsted manufacture in the Russian Empire, using state of the art technology to create, and modern marketing techniques to promote, its product range and evolving image. Aspects of British and Polish social history are compared to assess the efficacy of introducing the model-community concept, in combination with a radical employment policy, to less industrially-developed Russian Poland. The instrumentality of an expatriate community of skilled Yorkshire foremen in diffusing British industrial technology throughout the Russian Empire is described, against a backdrop of political instability and social upheaval which dramatically impacted on business behaviour after 1905. / The full text was made available on 29th Nov 2017
192

Isoleringsmaterialets inverkan på energianvändning och klimatpåverkan : -En fallstudie

Håkans, Alexander, Östlund, Isaac January 2024 (has links)
Inom EU står byggnadssektorn för en hög andel av energianvändningen och medlemsländerna har satt upp mål för att minska energianvändningen. Målen som har fastställts i Sverige innebär att utsläppen av växthusgaser ska vara netto noll senast år 2045. I det här sammanhanget blir det extra viktigt att använda sig av tekniker som minskar CO2e-utsläppen och gynnar klimatet. En byggnads klimatskärm är en primär faktor till energianvändningen och det ställs höga krav på materialen som installeras i klimatskärmen. Det kommer i detta examensarbete utföras en fallstudie på en byggnad i Ljusne, Söderhamn. Här studeras tre olika isoleringsmaterial och två fönstertyper för att analysera deras påverkan på byggnadens energianvändning och för att ta fram det optimalaste alternativet ur ett klimatneutralt perspektiv. De material som studeras är mineralull, fenolskumskiva och termoträ samt vanligt fönster och passivfönster. För att besvara denna frågeställning utförs det energisimuleringar genom datorprogrammet BV2 samt beräkningar med materialens miljövarudeklarationer (EPD) för att analysera deras klimatpåverkan. Byggnadens klimatpåverkan beräknas med hjälp av byggsektorns miljöberäkningsverktyg (BM). I BM beräknas byggnadens utsläpp i koldioxidekvivalenter ut för renovering, energianvändning per år och under en livscykel på 50 år. Energisimuleringar utförda i BV2 visar att tilläggsisolering med fenolskum och fönsterbyte till passivfönster är den effektivaste metoden vid renovering av ytterväggen ur ett energieffektivt användningssätt. Då denna kombination har den lägsta energianvändningen, primärenergital och genomsnittlig värmegenomgångskoefficient. Det påvisar ett resultat med ett primärenergital på 72,5 kWh/m2 och en energianvändning på 116,8 kWh/m2. Men kombination av termoträ och passivfönster är den mest verkningsfulla på byggnadens klimatpåverkan. Detta illustreras i BM där klimatpåverkan för renovering är 2928,9 kg CO2e, energianvändning ger 3980,7 kg CO2e/år och klimatpåverkan för en livscykel på 50 år blir då 201 964 kg CO2e. Användningen av energisimuleringar gör att effektiva och klimatanpassade material kan studeras närmare för att avgöra dess betydelse. För att klimatmålen i Sverige och även EU ska kunna uppnås är behovet av verkningsfulla material väsentliga. Det här examensarbetet är en del i ledet mot ett klimatneutralt samhälle. / Within the European Union (EU), the building sector accounts for a high proportion of energy use and Member States have set targets to reduce energy use. The targets set in Sweden mean that greenhouse gas emissions should be net zero by 2045. In this context, it is particularly important to use technologies that reduce CO2 emissions and benefit the climate. A building’s envelope is a primary factor in energy consumption and high demands are placed on the materials installed in the climate screen. In this thesis, a case study will be carried out on a building in Ljusne, Söderhamn, Sweden. Three different insulation materials and two types of windows will be studied to investigate their impact on the building´s energy consumption and to find the most optimal alternative from a climate neutral perspective.  The materials studied are mineral wool, phenolic foam board and thermal wood, as well as ordinary windows and passive windows. To answer this question, energy simulations are carried out using the computer program BV2 and calculations on the materials environmental product declarations (EPD) to analyze their climate impact. The climate impact of the building is calculated using the building sector´s environmental calculation tool (BM). The BM calculates the building´s emissions in carbon dioxide equivalents for renovation, energy use per year and over a life cycle of 50 years.  Energy simulations performed in BV2 show that additional insulation with phenolic foam and window replacement with passive windows is the most efficient method for renovating the external wall from an energy efficiency point of view. As this combination has the lowest energy use, primary energy figure and average heat transfer coefficient. It demonstrates a result with primary energy figure of 72,2 kWh/m2 and an energy use of 116,8 kWh/m2. But the combination of thermal wood and passive windows is the most effective on the climate impact of the building. This is illustrated in BM where the climate impact for renovation is 2928,9 kg CO2e, energy use gives 3980,7 kg CO2e/year and the climate impact for a life cycle of 50 years is then 201 964 CO2e/kg. The use of energy simulations allows efficient and climate-friendly materials to be studied more closely to determine their importance. For the climate goals in Sweden and EU to be achieved, the need for efficient materials is essential. This thesis is part of the journey towards a climate-neutral society.
193

Edward III's war finance 1337-41 : transactions in wool and credit operations

Fryde, E. B. January 1947 (has links)
No description available.
194

Organometallics in the Stabilization of Dyed Fibres

Ayling, Neroli Kim January 2008 (has links)
It has been observed that in certain cases the exposure of dyed fibres to aging techniques results in the strengthening of fibres. This thesis explores the hypothesis that the strengthening is due to radical cross-coupling reactions that could be initiated through metal ion mediated photodecarboxylation. The approaches taken in this research include kinetic experiments (using flash photolysis), examination of possible cross-coupling experiments (using species of opposite charge), and the design and examination of small molecule model systems. A flash photolysis system was developed and used in attempts to determine the rates of photochemical product formation for cobalt(III) amino acid complexes. Lower limits have been established for the rate of product formation in these systems. The lower limits are: 2 x 10⁷ s⁻¹ for [Co(bpy)2(gly)]²⁺; 2 x 10⁷ s⁻¹ for [Co(tpa)(gly)]²⁺; and 5 x 10⁶ s⁻¹ for [Co(tpa)(aib)]²⁺, where bpy is 2,2'-bipyridine; gly is glycinate; tpa is tris(2-pyridylmethyl)amine; and aib is aminoisobutyrate. In past studies, the rates of a series of cobalt(III) amino acid complexes were reported as being the same, and much slower. It is thought that in these cases it may not be the rate of the formation of product that was being measured, but rather the response time of the electronics that was being observed. In this thesis the results obtained for the rate for the aib complex were somewhat lower than those of the gly complexes. This may imply, for the aib complex at least, the rate of the formation of the metallocycle is being observed (and not the response times of the electronics or other limitations of the instrumentation), but the data is poor and there is considerable doubt about this. The steady state photolysis of opposite charged species [Co(bpy)2(gly)]²⁺ and [Co(EDTA)]⁻ is reported. The reactions were carried out on a small scale in deuterated solvent for NMR spectrometry analysis and also on a large scale for the possible isolation and characterisation of the products. Evidence was found for a different reaction occurring when both complexes were present. The exact nature of the product remains elusive. A model system was designed in which a dinuclear ligand would bind to two metal centres and a fibre mimic would be later added. Eight ligands are discussed that could potentially bind two octahedral metal centres. They all had a xylene spacing group linking the two polydentate sites together. Five of the ligands have two bidentate binding sites. The other three had two tridentate sites. The binding sites in three of the bis(bidentate) ligands were based on ethane-1,2- diamine (en). Two of these ligands produced hypodentate monocobalt and sundentate dicobalt complexes. The other two bidentate ligands were based on 2- aminomethylpyridine (ampy). Both of these ligands degraded in the complexation reaction conditions. The binding sites in the tridentate ligands were all based on tacn. Once again, the principal products isolated were hypodentate systems in which only one metal ion was coordinated by the ligands. There is a distinct pattern observed in the xylene spaced ligands to form hypodentate complexes with cobalt(III) metal centred complexes. There is evidence of the di-nuclear species from a reaction with a charcoal catalyst in the bis(bidentate) system. ¹H NMR spectrometry, ¹³C NMR spectrometry, elemental analysis, X-ray crystallography and UV-vis spectroscopy were used to study and characterise the complexes and ligands that were prepared in this project.
195

Fuktproblem i putsade fasader : Enstegstätade ytterväggar utsatta för slagregn

Tell, Emma, Jansson, Oskar January 2016 (has links)
One purpose of this work was to examine if a modification of the exterior insulation finishing system can lower the number of outer walls damaged by damp. The modification is the cut of the cellular plastic which is 45 degrees instead of a horizontal cut. One other purpose was; is cellular plastic or mineral wool better as insulation to minimize the dampness in this type of outer walls? A third purpose was to examine if there is any difference of dampness in the outer walls if using a gravel bed or concrete stones next to the outer wall. To examine these three purposes a laboratory experiment with three test walls with an exterior insulation finishing system was built. The difference between the three walls was the insulation. One wall was built with mineral wool with a horizontal cut, one with cellular plastic with a horizontal cut and the third with cellular plastic with a cut of 45 degrees. Simulations of pelting rain and measurements of dampness were carried out for 21 days. The measurements were taken at the same time every evening. After 21 days small samples of tree from the walls was weight, dried in an oven and then weight again to get the quantity of moisture in the samples before they were dried. A diffusion calculation of two outer walls, one with cellular plastic and one with mineral wool, was completed to examine the difference between the relative humidity in the walls. An identical calculation without a plastic film was executed too. The result of the calculations showed a minimal difference in the walls built with a plastic film. When the film was removed the result presented critical values. The result of the laboratory experiment indicates that the test wall with the cut of 45 degrees is better than the walls with a horizontal cut of the insulation. The differences were minimal but possible to read. Some critical, too high, values regarding the moisture content in wood were found and they came from the sills in the walls that had insulation with horizontal cuts. Of the two insulation types the result of calculations and laboratory experiment shows a minimal difference but they both indicates a better result for the mineral wool. The conclusion of this work indicates that cellular plastic with a 45 degree cut is slightly better than the horizontal cut. The comparison of cellular plastic and mineral wool indicates that the mineral wool is better. Another conclusion of this work is that the material on the ground next to the outer wall did not alter the dampness in the wall.
196

Concreto auto-adensável, de alta resistência, com baixo consumo de cimento Portland e com adições de fibras de lã de rocha ou poliamida / High strength self-consolidating concrete, with low content of cement Portland and addition of polyamide or rock wool fibers

Pereira, Tobias Azevedo da Costa 28 April 2010 (has links)
O objetivo deste trabalho é apresentar uma metodologia que possibilita a obtenção de uma linha de concretos auto-adensáveis de alta resistência, econômicos e com reduzido impacto ambiental quando comparados com os concretos correntes. Para atingir estes resultados foram estabelecidos critérios de dosagem e de produção visando à sinergia entre os materiais constituintes do concreto. Foram pesquisados métodos de empacotamento dos agregados e adições minerais, estudada a interação entre o aditivo superplastificante e os materiais cimentícios e a incorporação de fibras de lã-de-rocha ou poliamida. Os concretos com matriz densa sob efeito de temperaturas elevadas tendem a sofrer lascamentos explosivos. Diante disso foi verificado o comportamento de corpos de prova e os resultados indicaram a importância da adição da fibra de poliamida nessa condição, onde o concreto resistiu a uma temperatura de 400ºC. Ensaios de resistência à abrasão indicaram que a fibra de lã-de-rocha melhora essa propriedade do concreto e, como esperado, essa adição não inibe o lascamento explosivo do concreto. Também foram determinadas as propriedades mecânicas dos concretos e concluiu-se que é possível o emprego de um concreto estrutural auto-adensável com consumo de cimento Portland da ordem de 325 kg/\'M POT.3\', fc7 = 53 MPa, fc28 = 71 MPa e Ec28 = 43 GPa. Devido à ação das adições minerais, estes concretos atingiram uma grande reserva de resistência à compressão após a idade de referência de 28 dias, obtendo-se 89 MPa aos 131 dias de idade. A densificação da pasta hidratada, a melhoria da zona de interface desta com os agregados, além da fissuração reduzida decorrente do baixo consumo de cimento e da adição de fibras indicam que este material tem desempenho superior ao prescrito pela NBR 6118 para as diversas classes de agressividade ambiental e de resistência. / The aim of this work is to show a methodology that allows to realize a set of high strength self-consolidating concrete, economic and with lower environmental impact when compared with current concretes. To get these results, criteria for production and mix design had been established aiming at to synergy between constituent materials of the concrete. Methods of particles packing (aggregates and mineral additions), the interaction between the superplasticizer and cementitious materials and the fiber incorporation were researched. The concretes with dense matrix under effect of high temperatures are susceptible to explosive spalling. In this situation, concretes were evaluated by testing cylindrical specimens and results evidenced the importance of the polyamide fiber when the concrete supported 400ºC. Tests of abrasion resistance indicated a good application for the wool-of-rock fiber, but this material not avoids explosive spalling. The mechanical properties of the concretes were determined and show that is possible to product a self consolidate concrete with low cement content (325 kg/\'M POT.3\'), fc7 = 53 MPa, fc28 = 71 MPa and Ec28 = 43 GPa. Due to action of the mineral additions, these concretes had a great reserve of compressive strength after the age of reference of 28 days and achieved 89 MPa at 131 days of age. The high density cement paste, the improvement of the matrix-aggregate interfacial zone and the reduced cracking due to the low cement content and the fibre addition indicate that these materials has superior performance to those prescribed for the NBR 6118 for diverse strength classes and aggressive environmental exposure.
197

Optimierung der Glaswollefiltration von menschlichen Ejakulaten zum Zwecke der assistierten Reproduktion für labordiagnostische Untersuchungen

Weber, Holm 01 April 1999 (has links)
Mittels Glaswolle (Microfibre code 112) in einer speziellen Filtrations-Anordnung steht ein effektives Spermienpräparationsverfahren zur Verfügung. Durch Ausnutzung eines gefäßforminduzierten Konzentrierungseffektes kann auf samenzellschädigende Zentrifugation zur Spermatozoen-Anreicherung verzichtet werden. Folgend aufgeführte Ergebnisse sind Mittelwerte aus 30 Messungen. Die Computer-Assistierte Spermienmotilitäts-Analyse (CASA) zeigt eine gegenüber dem nativen Ejakulat signifikante Erhöhung der Spermienkonzentration im Filtrat (27,45 vs. 69,56 Mio/ml). Das Verteilungsverhältnis der Samenzell-Populationen nach Glaswolle- Filtration bietet gute Voraussetzungen für assistierte Reproduktion. Unter Abnahme des immotilen Anteils auf 1/5 (54,53 vs. 11,66 %), erhöht sich konsekutiv der motile Spermien-Anteil (39,53 vs. 82,06 %). In der weiteren Spezifisierung motiler Spermatozoen, kann eine Verschiebung zugunsten linear motiler Spermien registriert werden. Während die Verringerung der nicht linear motilen Subpopulation nur zufälligen Charakters ist, weist der Kreisläuferanteil post filtrationem einen signifikanten Rückgang auf (34,96 vs. 31,1 %). Der Zuwachs linear motiler Samenzellen ist jedoch von besonderem Interesse (7,36 vs. 12,43 %). Bei Zugrundelegung von Absolut- zahlenwerten, läßt sich (auch für oligozoosperme Ejakulate) ein nahezu 9-facher Anstieg linear motiler Spermatozoen von nativ 0,8 auf 7,1 Mio/ml nach Filtration demonstrieren. Ihre Spurgeschwindigkeit (curvilinear velocity-VCL) nimmt dabei überproportional zu (41,26 vs. 62,66 µm/s), während sich über alle motilen Spermien im Mittel nur eine filtrationsbedingte VCL-Erhöhung von 10 µm/s abzeichnet. Weiterhin kam ein Cell Counter + Analyser System (CASY®) zum Einsatz, das ein Verfahren der Partikelmeßtechnik nutzt. So gelang der Nachweis, daß die Glaswolle-Filtration unter Reduktion klein- und großkorpuskulärer Bestandteile (zelluläre und nichtzelluläre) eine deutliche Anreicherung einer Samenzell-Population mit medianen Membrandurchmesser von 3,47 µm bewirkt. Die Ergebnisse der morphologischen Differenzierung (strict criteria) stehen damit im Einklang. Nach Filtration konnte eine signifikante Zunahme der Normalform (13,33 vs. 19,16 %) bei adäquater Verminderung von Makro- und Mikroköpfen (6,5 vs. 3,03 %) sowie Vorstufen (8,33 vs. 5,96 %) registriert werden. Auf den raster-elektronen-mikroskopischen Aufnahmen wird deutlich, wie besonders membrandefekte Spermatozoen und muköses Eiweiß der Glaswolle-Faseroberfläche verhaften. / An efficient procedure for sperm preparation is presented using glass wool (microfibre code 112) in a special filter arrangement. Centrifugation as a means of spermatozoa concentration, a process which is extremely harmful to the sperm cells, can be dispensed with by making use of a concentration effect induced by the form of the vessel. The results that follow are mean values from 30 measurements. Computer-Assisted Sperm-motility Analysis (CASA) shows a significant rise of the sperm cell contents in the filtrate (27,45 vs. 69,56 million/ml) as compared with the native ejaculate. The distribution ratio of sperm populations observed after glass wool filtration provides favourable conditions for assisted reproduction. Reduction of the immotile portion to one fifth (54,53 vs. 11,66 %) yields a consecutive rise of the portion of motile sperms (39,53 vs. 82,06 %). Further specification of motile spermatozoa shows a shift in favour of sperms moving in a straight line. The decrease of the portion moving in circles is significant (34,96 vs. 31,1 %) after filtration, whereas the reduction in the subpopulation of sperms not moving in a straight line is of a rather incidental nature. Of particular interest, however, is the increase in sperm cells moving in straight lines (7,36 vs. 12,43 %). Basing considerations on absolute figures , a nine-fold increase in spermatozoa moving in straight lines, from the native value of 0,8 to 7,1 million/ml, can be demonstrated (even for oligozoospermial ejaculates) after filtration. Their curvilinear velocity (VCL) rises, in this connection, to a disproportionately high degree (41,26 vs. 62,66 µm/sec), whereas a filtration-induced rise of the VCL by only 10 µm/sec is observed for all motile spermatozoa on the average. Furthermore, a Cell Counter + Analyser System (CASY®) was employed making use of a particle test procedure. In this way, it could be proved that glass wool filtration produces a marked enrichment in a population of sperm cells with a mean membrane diameter of 3,47 µm with simultaneous reduction of the small- and large-corpuscular (cellular and non-cellular) fractions. In keeping with this are the results of the morphological differentiation (strict criteria). A significant increase in the standard form (13,33 vs. 19,16 %) with an adequate reduction in macro and micro heads (6,5 vs. 3,03 %) as well as in prestages (8,33 vs. 5,96 %) could be observed after filtration. Pictures taken with the electron-scan microscope clearly show that spermatozoa presenting membrane defects as well as mucous proteins, in particular, attach to the glass wool fibre surface.
198

Identifizierung und Charakterisierung natürlicher Rohstoffe als Bodenverbesserungsmittel sandiger Substrate

Garz, Kathleen 20 October 2017 (has links)
Ziel der vorliegenden Arbeit war es, natürliche Rohstoffe als potentielle Bodenverbesserungsmittel zu identifizieren und zu charakterisieren. Es sollte deren Eignung überprüft werden, ein sandiges Substrat in seinen chemischen, physikalischen und biologischen Eigenschaften messbar zu beeinflussen. Anhand von Versuchsreihen im Gewächshaus und im Freiland ist die differenzierte Wirkung der Rohstoffe auf Mais und Weizen getestet worden. Aufgrund einer Literaturrecherche wurden Rohwolle, Schafwollpellets und Biertreber betrachtet. Es zeigte sich für Biertreber, dass dieser große Mengen an Stickstoff (Nt=3,95%; C/N=12,74) bereitstellen kann. Zudem enthält er vergleichsweise viel Phosphor und Magnesium (8,68 g kg-1 und 4,05 g kg-1) aber nur geringe Mengen an Kalium (1,40 g kg-1). Weiterhin lässt sich bei Aufwandmengen von 0,5 M.-% eine kurzfristige Verbesserung der Wasserspeicherfähigkeit sandiger Substrate feststellen. Rohwolle weist im Vergleich zu Biertreber mit Nt=13,56% höhere Mengen an Stickstoff auf. Weiterhin lassen sich mit 35,41 g kg-1 höhere Mengen an Kalium aber mit nur 0,23 g kg-1 bzw. 0,34 g kg-1 geringere Mengen an Magnesium und Phosphor feststellen. Die Mineralisierung der Rohwolle erfolgt im Vergleich zu Biertreber langsam, sodass die enthaltenen Nährstoffe nur langsam pflanzenverfügbar werden. Rohwolle weist zunächst einen stark hydrophoben Charakter auf. Mit zunehmendem Abbau des Lanolins führen Aufwandmengen von 0,1 M.-% zu einer messbaren Erhöhung der Wasserspeicherfähigkeit des sandigen Substrates. Pflanzenverfügbare Nährstoffe stehen bei den industriell aufbereiteten Schafwollpellets im Vergleich zu reiner Rohwolle schneller zur Verfügung. Ähnlich wie bei der Rohwolle werden auch durch Schafwollpellets langfristig Nährstoffe freigesetzt und die Beeinflussung der bodenphysikalischen Parameter ist über längere Zeiträume nachweisbar. Allerdings müssen Aufwandmengen von 0,5 M.-% erbracht werden. / The aim of the study was to identify and characterize natural raw materials as a potential soil improver. The capacity for measurable influence on the chemical, physical and biological properties of sandy substratum was investigated. The differentiated affect of the raw materials has been tested for maize and wheat using test series in a greenhouse as well as in open fields. Raw wool, sheep wool pellets and spent grains were considered based on comprehensive literature research. It was observed that spent grains can provide large amounts of nitrogen (N=3.95\%; C/N=12.74). Moreover, it contains relatively high levels of phosphorus and magnesium (8.68 g kg-1 and 4.05 g/kg, respectively), but only small amounts of potassium (1.40 g/kg). Furthermore, a short-term improvement of the water storage capacity of sandy substratum using a application rate of 0.5 M.-\% was observed. Raw wool has higher amounts of nitrogen with Nt=13.56\% compared to spent grains. Moreover, higher levels of potassium with a value of 35.41 g/kg were observed, but spent grains have lower levels of magnesia and phosphor with values of 0.23 g/kg and 0.34 g/kg, respectively. The mineralization of the raw wool occurs slowly compared to (malt) spent grains, such that nutrients are slowly available to plants. Initially, raw wool has a highly hydrophobic character with increasing depletion of Lanolin a measurable improvement of the water storage capacity of sandy substratum using an application rate of 0.1 M.-\% was observed. Nutrients available to plants are provided quicker by industrially remanufactured sheep wool pellets in comparison to raw wool. Nutrients are released on a long-term basis by sheep wool pellets similar to the raw wool and the influence on the soil-physical properties are verifiable for longer periods of time. However, an application rate of 0.5 M.-\% is necessary.
199

Caracterização térmica de amostras de esponja sintética dupla face e palha de aço / Thermal characterization of synthetic sponge double sided and straw steel samples

Neres, Renata Aparecida 31 October 2014 (has links)
Este trabalho tem por objetivo a caracterização comparativa do comportamento de degradação e/ou decomposição térmica da esponja sintética dupla face, base poliuretana (parte amarela e parte verde), e da palha de aço, a partir das técnicas termoanalíticas. As esponjas sintéticas para limpeza doméstica, em substituição à palha de aço, apesar da vantagem econômica, podem apresentar restrições de descartes para o meio ambiente ou expor o usuário a riscos de contaminação. Amostras de esponja sintética dupla face (verde e amarela) e de palha de aço foram caracterizadas por análise térmica (TG/DTG, DTA e DSC) empregando atmosfera dinâmica de ar e de N2. Essas amostras foram estudadas por métodos cinéticos por termogravimetria isotérmica e não isotérmica. Os parâmetros cinéticos obtidos permitiram estimar os tempos necessários para a decomposição de ambas as partes da amostra da esponja sintética e também da palha de aço sob atmosfera de ar. Os resultados evidenciaram claramente que a matriz polimétrica da esponja sintética para ser degradada completamente exige um tempo muito longo, acima de 20.000 anos. Por outro lado, os resultados indicaram comportamento similar entre as amostras de esponja sintética e de palha de aço considerando apenas o efeito temperatura e tipo de atmosfera. Contudo, no cotidiano sabe-se que a palha de aço se oxida muito facilmente sob atmosfera de ar na presença de umidade. / This work aims at a comparative characterization of degradation behavior and/or thermal decomposition of synthetic double-face sponge, polyurethane base (yellow part and green part), and steel wool, from thermoanalytical techniques. Synthetic sponges for household cleaning, replacing steel wool, despite the economic advantage, may have restrictions on discharges to the environment or expose the user to risks of contamination. Samples dual synthetic sponge face (green and yellow) and steel wool were characterized by thermal analysis (TG/DTG and DTA DSC) employing an atmosphere of air and N2. These samples were studied by kinetic methods isothermal and non-isothermal thermogravimetric analysis. The kinetic parameters obtained allowed the estimation necessary for decomposition of the sample both sides of the synthetic spomge and also of steel straw times under air atmosphere. The results clearly showed that polymetric matrix of synthetic sponge to be degraded completely requires a very long time, over 20,000 years. Moreover, the results showed similar behavior among synthetic sponge and steel wool sample considering only the effect of temperature and type of atmosphere. However, in daily life it is known that the steel wool oxidizes very easily under air atmosphere in the presence of moisture.
200

Produção e caracterização da cerâmica vermelha com a adição de resíduos oriundos da lavagem da lã de ovinos

Nunes, Francine Machado 01 June 2016 (has links)
Submitted by Andrea Pereira (andrea.pereira@unipampa.edu.br) on 2017-03-13T18:17:27Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação de Mestrado_Francine Nunes_2016.pdf: 2824304 bytes, checksum: aa5a2fd56f57a8f91e1f2bcc17666fd3 (MD5) / Approved for entry into archive by Andrea Pereira (andrea.pereira@unipampa.edu.br) on 2017-03-13T18:18:32Z (GMT) No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação de Mestrado_Francine Nunes_2016.pdf: 2824304 bytes, checksum: aa5a2fd56f57a8f91e1f2bcc17666fd3 (MD5) / Made available in DSpace on 2017-03-13T18:18:32Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação de Mestrado_Francine Nunes_2016.pdf: 2824304 bytes, checksum: aa5a2fd56f57a8f91e1f2bcc17666fd3 (MD5) Previous issue date: 2016-06-01 / A utilização de cinzas de resíduos sólidos para a fabricação de produtos cerâmicos tem apresentado evidências a fim de melhorar as propriedades químicas, físicas e mecânicas, minimizar os problemas ambientais e reduzir o volume de extração de matéria-prima argilosa. Em vista disso, o presente trabalho tem como objetivo avaliar a possibilidade de fabricar produtos cerâmicos a base de argila mais a adição de cinza de resíduo de lã de ovinos em diferentes percentuais, tendo por finalidade a aplicação na construção civil. O resíduo é proveniente do processo de beneficiamento da lã de ovinos em uma indústria têxtil, sendo que este foi queimado ao ar livre e peneirado em um conjunto de peneiras 20, 30, 40, 60 e 80 mesh. Foram realizadas formulações contendo apenas argila in natura e com adições de cinza de lã (CL) em percentagens de 5, 10, 20 e 30 % na massa de cerâmica vermelha, sendo submetidas à caracterização química pela Fluorescência de Raios-X (FRX) e Espectroscopia de Absorção na Região do Infravermelho com Transformada de Fourier (FT-IR); mineralógica com Difração de Raios-X (DRX); térmica pela Análise Termogravimétrica (TG) e Calorimetria Exploratória Diferencial (DSC); e física por meio da distribuição granulométrica e índices físicos. A conformação das amostras foi realizada por prensagem e extrusão à vácuo. E as contrações lineares de secagem e de sinterização, também foram avaliadas. A sinterização dos produtos cerâmicos foi realizada em temperaturas de 600, 700 e 800 °C, com taxa de aquecimento de 100 °Cmin-1 e patamar de sinterização de três horas. As propriedades estruturais dos produtos foram realizadas por meio de FT-IR e DRX, e a resistência mecânica pela tensão de ruptura à flexão. Outras análises físicas como contrações lineares de secagem, porosidade aparente, massa específica aparente e absorção de água, também foram avaliadas. Para a resistência mecânica a média dos valores obtidos variou de 0,38 ± 0,15 MPa a 6,70 ± 0,76 MPa, e para absorção de água, a média dos valores foi de 14,72 ± 0,39 % a 27,60 ± 1,05 %, para os produtos cerâmicos prensados. A avaliação destes mesmos parâmetros para os produtos cerâmicos extrudados, apresentou variação de 2,38 ± 1,47 MPa a 7,38 ± 3,00 MPa e de 8,57 ± 0,68 % a 24,80 ± 1,08 %. A resistência mecânica e absorção de água obtiveram melhores valores na temperatura de queima a 800 °C. No entanto, os valores encontrados foram abaixo do esperado devido aos produtos cerâmicos extrudados apresentar patologias como o “coração negro”. / The use of solid ash residue for the manufacture of ceramic products has been evidence to improve the chemical, physical and mechanical properties, minimizing environmental problems and reduce the volume of extraction clayey raw materials. In view of this, the present study aims to evaluate the possibility to make ceramics by the clay added by sheep wool waste ash, in different percentages. The purpose of this application is the construction bricks. The residue is derived from the beneficiation process of the sheep wool into a textile, and this was burnt at the air and sieved in a set of sieves 20, 30, 40, 60 and 80 mesh, only formulations were made containing clay and wool gray additions (CL) in percentages of 5, 10, 20 and 30 % in a red ceramic, being subjected to chemical characterization by X-Ray Fluorescence (XRF) and Fourier Transform in the Infrared Spectroscopy (FT-IR); Mineralogical with X-Ray Diffraction (XRD); Thermal by Thermogravimetric Analysis (TG) and Differential Scanning Calorimetry (DSC); through of physical and particle size distribution and physical indexes. The conformation of the samples was accomplished by pressing and vacuum extrusion. And the linear shrinkage by drying and heating, were also evaluated. The sintering of the ceramic products is performed at temperatures of 600, 700 and 800 °C with a the rate of 100 °Cmin -1 and three hours burning level. The structural properties of the products were performed by FT-IR and XRD, and the mechanical strength of the flexural breaking strain. Other physical analysis such as linear shrinkage drying, porosity, bulk density and water absorption were also evaluated. For mechanical strength average values obtained ranged from 0.38 ± 0.15 MPa to 6.70 ± 0.76 MPa and water absorption, the average value was 14.72 ± 0.39 % and 27.60 ± 1.05 % for the ceramics pressed. The evaluation of these same parameters for extruded ceramics, changed from 2.38 ± 1.47 MPa to 7.38 ± 3.00 MPa and 8.57 ± 0.68 % to 24.80 ± 1.08 %. The mechanical strength and water absorption values obtained in the best heating temperature to 800 °C. However, the values were lower than expected due to the extruded ceramic products present conditions as the “black core”.

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