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1

Cuoghi, Giulia. "Theoretical and experimental behavior of prestressed natural stone beams". Master's thesis, Alma Mater Studiorum - Università di Bologna, 2018.

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L’obiettivo di molte ricerche attuali riguarda nuove soluzioni costruttive per l'edilizia futura. In particolare, la ricerca si focalizza sullo sviluppo tecnologico di materiali naturali preesistenti con lo scopo di realizzare strutture innovative, sicure ed ecosostenibili. La presente tesi si propone di studiare la possibilità di utilizzare materiali naturali, come la pietra, per la costruzione di strutture portanti. Il calcare Cabouca è stato scelto per la realizzazione di una trave a blocchi, resa resistente e compatta attraverso la tecnica della precompressione. Le prove meccaniche sui campioni di pietra e successivamente, la costruzione e la prova a flessione della trave sono stati effettuati presso il Laboratório de Estruturas Pesadas, Faculdade de Ciências e Tecnologia, presso l'Università di Lisbona. I risultati soddisfacenti hanno evidenziato un sostanzioso incremento della capacità flessionale della trave precompressa rispetto a quella non armata, potendo quindi dimostrare che la precompressione è efficace nella pietra naturale come nel calcestruzzo. Il presente lavoro si propone come un punto di partenza valido per l'evoluzione di strutture portanti in pietra precompressa eleganti, sicure e conformi ai principi del Green building.
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2

Huck, Scott W. "Controls on Natural Fractures in the Upper Lexington Limestone and Point Pleasant Formation: Central-Ohio". Bowling Green State University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1372061876.

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3

Dias, Luís Carlos Rosmaninho. "STONECOLOR: color of commercial marbles and limestone - causes and changes". Doctoral thesis, Universidade de Évora, 2020. http://hdl.handle.net/10174/26969.

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Historically centred in the European and Asiatic countries, the ornamental stone production is currently one of the most important sectors for the Portuguese economy. In fact, Portugal is today one of the leaders in the production of natural stone worldwide, namely in the limestone and marble exploitation. The production increment over the last several years is related with the high quality of the carbonated stones existing in the Portuguese territory together with the Portuguese experience in stone manufacture, acquired since ancient times. In this context, colour is one of the most important visible aspects of natural stone, for the construction/restoration of new buildings and/or for Cultural Heritage preservation. Therefore, colour and discolouration of stone is currently an important research topic for the scientific community, where the association stone-colour-microorganism is still unexploited. This PhD aimed to determine the causes that affect the colour of Portuguese marbles and limestones. Therefore, several lithotypes of natural stone with high relevance for the Portuguese natural stone industry and for Cultural Heritage assets were selected and studied. In order to characterise discolouration phenomena, the processes of natural stones’ weathering were assessed, and the microbiota thriving on the stones was determined. The microorganisms’ contribution for the stone discolouration phenomena was evaluated through the execution of artificial ageing assays, under controlled environment. The results obtained allowed to identify the main chromophore components of the Portuguese carbonated stones studied. It was also finding and determined that the colour change occurred on the blue limestone is achieved through the natural weathering of pyrite, and this mechanism is accelerated when microorganisms are present. Regarding the cultural heritage assets study, it was finding that colour alterations of the stone are caused mainly by chemical and biogenic actions; Resumo: Tradicionalmente centrada nos países Europeus e Asiáticos, a produção de Pedra Ornamental tem-se tornado num dos mais importantes setores da economia Portuguesa. Portugal é hoje, de facto, um dos líderes ao nível mundial na produção de Pedra Natural, nomeadamente de calcários e mármores. O aumento na produção ao longo destes últimos anos está relacionada não só com a elevada qualidade das rochas carbonatadas que aqui se encontram, mas também com a experiência portuguesa no manuseamento da Pedra. A cor, neste contexto, é um dos aspetos visíveis mais importantes na Pedra Natural, tanto na construção/restauro de novos edifícios como na preservação de Património Cultural. Deste modo, a cor e a descoloração da Pedra tem-se tornado num dos importantes tópicos de investigação para a comunidade científica, onde uma das lacunas é a falta de associação pedra-cor-microorganismo. Com este projeto pretendeu-se contribuir para a compreensão das causas de cor em rochas carbonatadas portuguesas, como o calcário e o mármore, onde foram selecionados e estudados diversos litótipos de Pedra Natural com elevada relevância para a indústria da Pedra portuguesa e para o património cultural construído. Para caracterizar fenómenos de descoloração, foram estudados os processos de meteorização de rochas e foi determinado o estado de biocolonisação do material. O contributo dos microorganismos para o fenómeno de descoloração de Pedra foi avaliado através da execução de ensaios de envelhecimento artificial, sob ambiente controlado. Os resultados obtidos permitiram identificar os principais elementos cromóforos das rochas carbonatadas portuguesas estudadas. Foi ainda determinado que a alteração da cor no calcário azul é causada pela pela meteorização natural da pirite, e que este mecanismo é acelerado na presença de agentes microbianos. Relativamente ao estudo dos bens patrimoniais, foi determinado que as alterações cromáticas aqui presentes são sobretudo de origem química e biogénica.
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4

Bell, James Robert. "Habitat use, community structure and biogeography of spiders (Araneae) in semi-natural and disturbed limestone grassland". Thesis, Manchester Metropolitan University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.297980.

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5

Hornbeck, Joseph R. "A Comparison of the Ichthyofaunal Trophic Ecology at Selected Limestone Artificial Reef Sites and Adjacent Natural Reef Sites". NSUWorks, 2017. http://nsuworks.nova.edu/occ_stuetd/438.

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Artificial reefs may enhance the biological production of reef-associated flora and fauna, but their trophic structure relative to that of natural reefs remains understudied. We assessed trophic dynamics by comparing δ13C and δ15N in 43 fish species from artificial and natural reef tracts of Broward County, Florida. We tested the effect of sampling location (artificial, first, and second reef), general feeding strategy (herbivore, omnivore, planktivore, invertivore, and carnivore), phylogeny, and standard length. For all samples, δ13C and δ15N ranged from -19.5 to -13.1‰ and 6.7 to 13.3‰, respectively. Lower trophic level feeding behavior resulted in more depleted δ13C and δ15N and higher trophic level feeding behavior resulted in more enriched δ13C and δ15N. We detected significant effects of both general feeding strategy and phylogeny. We also detected significant differences in δ13C and δ15N profiles between artificial and natural reefs; however, these differences were not great enough to suggest changes in the feeding strategy or trophic dynamics of individual fish taxa.
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6

Prestes, Nelson Eduardo. "Calagem, adubação e introdução de espécies em pastagem natural do Planalto Catarinense". Universidade do Estado de Santa Catarina, 2015. http://tede.udesc.br/handle/handle/533.

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The aim of this work was to evalute herbage production of a natural grasslands submitted to limestone and phosphorus levels, applied superficially, without introducing species (Chapter 1) and overseeded with temperate climate species (Chapter 2). The experiment was conducted from January 2010 to December 2013. In Chapter 1 liming was applied in quantities of 0.0; 7.2 and 14.4 t ha-1; and phosphorus as triple superphosfate, at levels of 0; 35; 70 and 140 kg ha-1 P2O5. The experimental design was a randomized block design in a split plot arrangement with 3 repetitions, with limestone levels distributed in the main plots and P in the subplots. There was no significant interaction between the limestone and phosphate treatments in both studies. The elevation of limestone increased forage production only from the 3rd year, a linear response, with maximum value of 1182.3 kg DM ha-1, with 14.4 t ha-1 lime, and quadratic in 4th year, with 2316.1 kg DM ha-1, with 7.2 t ha-1 of lime. There was statistical difference at P applications from the 2nd year, with the greatest production obtained in the 4th year, with 140 kg P2O5 ha-1 producing 2232.8 kg DM ha-1. Limestone promoted changes up to 10cm of soli layer. Of 0-5cm, 14.4 t ha-1, increased pH from 4.77 to 6.45, Al decreased from 2.51 to 0.0 cmolc kg-1 and base saturation (V%) increased from 31.34 to 84.17%. With the P levels changes occured mainly up to 5cm. Chapter 2: limestone in 3.6; 7.2; 11.0 and 14.4 t ha-1; and P in doses of 35; 70; 105 and 140 kg P2O5 ha-1, and overseeded species of cold season the maximum production was of 3932.2 kg DM ha-1 in the 2nd year with a dose of 11 t of limestone. The red clover responded better to this limestone application on levels 7-11 t ha-1. Phosphorus significantly increased herbage production in four years. Forage production reached the ceiling in the 2nd year, 4419.4 kg DM ha-1 with 140 kg P2O5 ha-1. The red clover was established and persisted better than the other species with increasing levels of limestone and limestone and P. The P, mainly concentrated their effects up to 5cm of soil layer. A 14.4 tonnes of applied lime the pH reached 6.04, Al 0.03 kg cmolc V-1 and 74.56% at%. At the same soil layer 140 kg ha-1 P2O5, P increased to 12.08 mg kg-1. Lime application of 25% (7.2 t ha-1) of the recommended dose, associated with phosphorus dose of 50% of the recommendation (70 kg P2O5 ha-1), potentiate the production of forage on native pasture with a predominance of Schizachirium tenerum. The application of 1/8 dose (3.6 t ha-1) of the lime requirement allows the establishment and persistence of legumes introduced in native grass; 1/8 (3.6 t ha-1) of the official recommendation of the dose associated with limestone phosphorus increasing doses increase linearly forage production. This enhancement is due primarily to the effect of P in the production increase of introduced legumes
Avaliou-se a produção de um campo nativo submetido a níveis de calcário e fósforo, aplicados superficialmente, sem a introdução de espécies (Capítulo 1) e com sobressemeadura de espécies de estação fria (Capítulo 2) de janeiro/10 a dezembro/13. No Capítulo 1 a calagem foi de 0,0; 7,2 e 14,4 t ha-1; e aplicação de SFT, nosníveis de 0; 35; 70 e 140 kg de P2O5 ha-1. O delineamento experimental dos ensaios foi de blocos ao acaso com parcelas subdivididas, com 3 repetições, com níveis de calcário distribuídos na parcela principal e as doses de P nas sub-parcelas. Não houve interação significativa entre os tratamentos de calcário e fósforo nos dois estudos. A elevação das doses de calcário aumentou a produção de forragem somente a partir do 3º ano, sendo a resposta linear, com valor máximo de 1.182,3 kg MS ha-1, com 14,4 t de calcário ha-1, e quadráticano 4º ano, com 2.316,1 kg MS ha-1, com 7,2 t de calcário ha-1. Houve diferença estatísticaàs aplicações de P a partir do 2º ano, sendo a maior produção obtida no 4º ano, com 140 kg P2O5 ha-1 produzindo 2.232,8 kg MS ha-1. O calcário promoveu maiores alterações até 10cm. De 0-5cm, 14,4 t ha-1, elevou o pH de 4,77 para 6,45, o Al reduziu de 2,51 para 0,0 cmolc kg-1 e a saturação por bases (V%) aumentou de 31,34 para 84,17%. Com as doses de P,acréscimos importantes limitaram-se principalmente até 5cm. Capítulo 2: com calcário em 3,6; 7,2; 11,0 e 14,4 t ha-1; e P nas doses de 35; 70; 105 e 140 kg de P2O5 ha-1, e com sobressemeadura de espécies de estação fria, o calcário, com 11 t ha-1, teve com produção máxima 3.932,2 kg MS ha-1, no 2º ano. O trevo-vermelho respondeu melhor a este corretivo, nos níveis de 7 a 11 t ha-1. O P foi significativo à produção de forragem nos quatro anos. A forragem atingiu o teto produtivo no 2º ano, 4.419,4 kg MS ha-1 com 140 kg P2O5 ha-1. O trevo-vermelho se estabeleceu e persistiu melhor que as demais espécies com os níveis crescentes de calcário e P. O calcário e P, concentraram seus efeitos principalmente até 5cm. Com 14,4 t de calcário o pH chegou a 6,04, o Al a 0,03 cmolc kg-1 e a V% a 74,56%. Nesta camada, 140 kg P2O5 ha-1, elevou o P para 12,08 mg kg-1. Aplicação de calcário de 25% (7,2 t ha-1) da dose recomendada, associada com dose de fósforo de 50% da recomendação (70 kg P2O5 ha-1), potencializam a produção de forragem em campo natural com predomínio de Schizachirium tenerum.A aplicação de dose de 1/8 (3,6 t ha-1) da recomendação de calcário permite o estabelecimento e a persistência de leguminosas introduzidas em campo nativo; 1/8 (3,6 t ha-1) da dose da recomendação oficial de calcário associada com doses crescentes de fósforo aumentam linearmente a produção de forragem. Essa potencialização se deve, principalmente, ao efeito do P no incremento produtivo das leguminosas introduzidas
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7

Grill, Nicolette Deannah. "ECONOMIC GEOLOGY OF THE SAN BERNARDINO MOUNTAINS, CALIFORNIA". CSUSB ScholarWorks, 2014. https://scholarworks.lib.csusb.edu/etd/102.

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The San Bernardino Mountains are well known for their rich mining history, especially, gold in the mid-1800s and the current mining of one of the world’s largest deposits of high purity limestone. The purpose of this study was to compile new, current, and historical data of the major economic resources that are present and mining that has gone on in the San Bernardino Mountains. It is estimated that historical mining of the Holcomb Valley recovered $457,660,000 of gold or about 350,000 troy ounces based on samples collected for this study and 2013 gold price. The current major geologic resource is the limestone deposits on the north slope of the San Bernardino Mountains. Presently, there are three operators: Omya, Specialty Minerals, and Mitsubishi Cement. The San Bernardino Mountains are well known for skarn gold deposits. New work indicates that the placer gold from Holcomb Valley is often of very high purity. Placer gold samples were analyzed using the scanning electron microscope and energy dispersive x-ray spectra to determine the purity of the gold. Rim and core analysis of the placer gold was used to determine if the gold was transported from its source and to give an estimate of transportation distance. Results show some of the placer gold of Holcomb Valley has been rounded and flattened by weathering and transportation with increased gold purity in the rims while other gold grains still sustain their octahedral crystalline structure. Rims range in gold purity from 84.26% to 100%, with core gold purity ranging from 79.51% to 99.79%. Gold samples were weighed, photographed, measured, and classified by shape, angularity and texture, to assess the effects of transportation. Gold weights where used to calculate an economic value of gold. Geographic Information System “GIS” was used to visually display geology, historical and current mine locations, locations of samples used in this study, and to help calculate the volume of the Holcomb Valley TsE rock unit, which is where the placer gold is deposited. Sediment sample 15 from TsE had the lowest gold value of .002 ounces per cubic yard. This value is inferred to represent the amount of gold remaining after mining. Based on this assumption and the estimated volume of TsE at 50,027,000 cubic yards, the estimated total weight of gold remaining in the deposit is about 100,000 troy ounces, with a dollar value of about $130,760,000, using gold values for 2013. Sample 17 had the highest gold value, with .014 ounces per cubic yard. This is inferred to represent the concentration of placer gold deposits within parts of Holcomb Valley that have never been mined. This yields a total weight of the deposit of roughly 700,000 troy ounces, with an estimated value of $915,320,000 using gold prices for 2013. The gold values were calculated using November 7, 2013 gold spot price of $1,307.60.
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8

Akhoondan, Mersedeh. "Corrosion Evaluation and Durability Estimation of Aluminized Steel Drainage Pipes". Scholar Commons, 2012. http://scholarcommons.usf.edu/etd/4273.

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Aluminized steel pipes are expected to have a long service life, e.g. 75 years. Spiral ribbed aluminized pipes (SRAP) have been widely specified and used by the Florida Department of Transportation (FDOT) for drainage of runoff water. Confidence in the long term durability of SRAP has been challenged by recent unexpected early corrosion failures in various Florida locations. SRAP premature corrosion incidents have occurred in two modalities. Mode A has taken place in near-neutral soil environments and has often been associated with either gross manufacturing defects (i.e. helical cuts) or corrosion concentration at or near the ribs. Mode B took place in pipes in contact with limestone backfill and corrosion damage was in the form of perforations, not preferentially located at the ribs, and not necessarily associated with other deficiencies. These failures motivated this research. The objectives of this work are to establish to what extent the Mode A corrosion incidents can be ascribed to manufacturing defects, that can be rectified by appropriate quality control, as opposed to an intrinsic vulnerability to corrosion of regularly produced SRAP due to ordinary forming strains and to determine the mechanism responsible for Mode B corrosion including the role that limestone backfill played in that deterioration. To achieve those objectives, laboratory experiments were conducted to replicate the conditions for Mode A and Mode B. Overall, the findings of this and previous work suggest that much of the corrosion damage observed in the Mode A incidents were promoted more by manufacturing deficiencies and less by any possible inherent susceptibility of corrosion at the ribs of SRAP that was produced following appropriate quality control. Experiments to explore the causes of Mode B corrosion showed that high pH values, sufficient to cause dissolution of the passive film on aluminum, can develop under exposure of limestone to flowing natural water. The findings substantiate, for the first time, an important vulnerability of aluminized steel in limestone soils and provide an explanation for the rapid onset deterioration observed at the field under Mode B. The findings also provide strong evidence in support of service guidelines to disallow the use of limestone bedding for aluminized steel pipe, including SRAP.
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9

Araújo, Bárbara Mafra de. "Influência de calagem e adubação fosfatada no crescimento inicial de Eucalyptus benthamii e Eucalyptus dunnii no Planalto Norte Catarinense". Universidade do Estado de Santa Catarina, 2014. http://tede.udesc.br/handle/handle/1960.

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Among the economically important species of eucalyptus for southern Brazil, the most suitable are Eucalyptus benthamii and Eucalyptus dunnii, due to its tolerance to low temperatures. However, there is little information about the nutritional requirements and studies showing aspects involving nutrition versus the development of these species. Coupled with the high demand for use of fertilizers and, in order to obtain substantial productivity gains for most of eucalyptus forests located in the South of Brazil soils, it is necessary to determine suitable doses depending of the soil type and the genetic material. This study aimed to evaluate the initial response of Eucalyptus benthamii and Eucalyptus dunnii to different doses of phosphorus fertilization and liming in the study region. There were specific objectives, as: to evaluate the initial growth of the plants of Eucalyptus benthamii and Eucalyptus dunnii, based on the dendrometric variables height and crown diameter; evaluate and interpret the effect of different doses of rock phosphate (RF), mixed mineral fertilizer (MF) and limestone in the initial growth of these species. Thus, it was conducted a field experiment, located in the city of Rio Negrinho - SC, in the period November 2012 to November 2013. The experimental design was a randomized block design with three replications, conducted in three 2 x 4 factorial schemes. Considering the A factor constituted by two species (Eucalyptus benthamii and Eucalyptus dunnii) and the B factor: a) four levels of RF (0, 400, 600 and 800 kg ha-1 in the form of reactive Gafsa RF); b) four doses of MF (0, 150, 200 and 250 kg ha-1 of NPK 6-30-6 formulation); c) four liming levels (0, 3.5, 6 and 10 t ha-1 in the form of dolomitic lime). The plots had 270 m² of area, with 45 plants in each. Total height measures and diameter of the tree canopy to 330 days after planting were performed. The results showed that the phosphate fertilizer (RF and MFM) and liming increased growth in height and crown diameter of Eucalyptus benthamii and Eucalyptus dunnii plants during the first 11 months of grow. The growth response of Eucalyptus benthamii was higher than Eucalyptus dunnii, in all evaluated factorial schemes. The lowest dose of RF was effective for the growth of Eucalyptus benthamii and obtained slightly higher growth for Eucalyptus dunnii when associated with dose of 6 t ha-1 of lime and, mainly, to 10 t ha-1 of lime. The higher dose of MF was effective on the Eucalyptus benthamii growth and slightly higher for Eucalyptus dunnii, but only when combined with a dose of 10 t ha-1 of lime. The lower dose of lime had satisfactory growth for Eucalyptus dunnii, while the higher dose of lime was effective in the growth of Eucalyptus benthamii, when associated with a dose of 400 kg ha-1 RF, a condition that was found slightly higher than results of the studied dendrometric parameters
Entre as espécies de eucalipto economicamente importantes para a Região Sul do Brasil, as mais indicadas são Eucalyptus benthamii e Eucalyptus dunnii, devido às suas tolerâncias às baixas temperaturas. No entanto, são escassas as informações sobre as exigências nutricionais e estudos que apresentem aspectos que envolvam a nutrição versus o desenvolvimento dessas espécies. Aliado a elevada demanda por utilização de fertilizantes e corretivos para que se obtenham ganhos substanciais de produtividade para grande maioria das florestas de eucaliptos situados nos solos do Sul do Brasil, é necessário determinar doses adequadas em função do tipo de solo e do material genético. O trabalho objetivou avaliar a resposta inicial de Eucalyptus benthamii e Eucalyptus dunnii a diferentes doses de adubação fosfatada e calagem na região do Planalto Norte Catarinense. Tendo como objetivos específicos: avaliar o crescimento inicial das plantas de Eucalyptus benthamii e Eucalyptus dunnii, a partir das variáveis dendrométricas altura e diâmetro de copa; avaliar e interpretar o efeito de diferentes doses de fosfato natural (FN), fertilizante mineral misto (FM) e calcário no crescimento inicial dessas espécies. Nesse sentido, foi conduzido experimento a campo, localizado no Município de Rio Negrinho SC, no período de novembro de 2012 a novembro de 2013. O delineamento experimental utilizado foi o de blocos ao acaso com três repetições, conduzido em três esquemas fatoriais 2 x 4. Sendo fator A constituído por duas espécies (Eucalyptus benthamii e Eucalyptus dunnii) e o fator B por: a) quatro doses de FN (0, 400, 600 e 800 kg ha-1 na forma de FN reativo de Gafsa); b) quatro doses de FM (0, 150, 200 e 250 kg ha-1 da formulação 6-30-6 de NPK); e c) quatro doses de calcário (0, 3,5, 6 e 10 t ha-1 na forma de calcário dolomítico). As parcelas possuíam 270 m² de área útil, apresentando 45 plantas em cada. Foram realizadas medidas de altura total e diâmetro de copa das árvores aos 330 dias após plantio. Os resultados mostraram que a adubação fosfatada (FN e FM) e a calagem aumentaram o crescimento em altura e diâmetro de copa das plantas de Eucalyptus benthamii e Eucalyptus dunnii durante os primeiros 11 meses de cultivo. A resposta de crescimento do Eucalyptus benthamii foi superior em relação ao Eucalyptus dunnii, em todos os esquemas fatorais avaliados. A menor dose de FN foi efetiva no crescimento de Eucalyptus benthamii e obteve crescimento ligeiramente superior para Eucalyptus dunnii, quando associada à dose de 6 t ha-1 de calcário e, principalmente, à 10 t ha-1 de calcário. A maior dose de FM foi efetiva no crescimento de Eucalyptus benthamii e ligeiramente superior para Eucalyptus dunnii, porém, somente quando associada à dose de 10 t ha-1 de calcário. A menor dose de calcário obteve crescimento satisfatório para Eucalyptus dunnii, enquanto a maior dose de calcário foi efetiva no crescimento de Eucalyptus benthamii, quando associada à dose de 400 kg ha-1 de FN, condição que foi constatada resultados ligeiramente superiores dos parâmetros dendrométricos estudados
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Soyluoglu, Serdar. "Effects Of Separate And Intergrinding On Some Properties Of Portland Composite Cements". Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/3/12611365/index.pdf.

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In the production of cement, to increase the cement/clinker ratio and decrease CO2 emission, the most important alternative is to produce mineral admixture incorporated cements (CEM II-III-IV-V) instead of portland cement (CEM I). These cements are usually produced by intergrinding the portland cement clinker and the mineral admixtures. However, the difference between grindabilities of the different components of such cements may cause significant effects on the particle size distribution and many other properties. For this reason, separate grinding of additives and clinker may be thought as an alternative. In this study, the effects of intergrinding and separate grinding on the particle size distribution and consequently on the strength of portland composite cements which contained natural pozzolan (trass), granulated blast furnace slag (GBFS) and limestone besides portland cement clinker were studied.
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11

Skriňáková, Eva. "Optimalizace složení betonů s využitím plniv z recyklovaných betonů". Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2016. http://www.nusl.cz/ntk/nusl-240222.

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Concrete as a building material is subject to continuous innovation and thanks to advanced technology and quantum of research, its properties are still improved. It is logical that the more concrete we produce, the more waste it arises. The volume of this waste can not be stored in landfills endlessly, nowadays most of the waste economies in the world are trying to recycle concrete rubble. The recycling is not such a problem, the technology has been long verified but the quality of the recycled concrete aggregate is unquestionably one of the primary assumption which leads to accomplish required properties of concrete. In fact, the recycling process is „crushing“ the concrete into particles with an effort to eliminate the cement paste on the surface of the aggregate. An ideal solution would be create a resistant and firm coating that would adhere perfectly to the cement matrix. This diploma thesis is focused on the properties of recycled concrete aggregate and methods of improvement and optimization of the concrete mix composition.
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Pestre, Tristan. "La pierre naturelle dans un contexte d'évolution réglementaire environnementale de la construction, étude des transferts hygrothermiques au sein de composants d'enveloppes de bâtiments". Electronic Thesis or Diss., Artois, 2021. http://www.theses.fr/2021ARTO0205.

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Dans un contexte de transition énergétique français, mais également international, le secteur de la construction reste l’un des plus impactant sur l’environnement et se doit d’évoluer pour en limiter les conséquences. En réaction, l’État a mis en place une expérimentation, « bâtiment à énergie positive et réduction carbone », préfigurant la future réglementation thermique des bâtiments, qui deviendra également environnementale.La plupart des matériaux naturels, locaux et peu transformés, ont des avantages environnementaux indéniables et les filières de proximité dont ils sont issus disposent de potentiels économiques et sociaux intéressants. Ces matériaux peuvent alors parfaitement s’intégrer dans une démarche de développement durable. Cependant, il est indispensable de connaître leur comportement physique pour pouvoir optimiser leur usage dans des constructions performantes, saines, confortables et durables.Ces travaux de recherche ont pour objectif de valoriser la pierre naturelle massive pour la construction de bâtiments énergétiquement performants et environnementalement respectueux.Une douzaine d’échantillons de roches a été caractérisée d’un point de vue thermique (résistance thermique et capacité thermique), d’un point de vue hydrique (absorption d’eau à pression atmosphérique, perméabilité à la vapeur d’eau, capacité tampon hydrique, sorption et désorption hygroscopique) et d’un point de vue environnemental (analyse de cycle de vie des maçonneries en pierres). Les résultats expérimentaux obtenus, s’ajoutant à la base de données du Centre Technique de Matériaux Naturels de Construction, ont permis de réaliser des études statistiques sur les pierres naturelles calcaires. Les perspectives seraient de pouvoir estimer leurs caractéristiques physiques et de les intégrer dans des modules de modélisation des informations du bâtiment (BIM) en plein développement.Les propriétés hygrothermiques des pierres ont également été utilisées comme données d’entrées pour étudier les transferts couplés de chaleur et d’humidité à plusieurs échelles, de la paroi au bâtiment. L’approche numérique a été comparée aux approches expérimentales (chambre bi-climatique et instrumentation in-situ d’une villa). L’objectif est de valider les modèles numériques utilisés et les résultats issus de la caractérisation en laboratoire. Enfin, une étude de simulation thermique dynamique comparative permet de dresser un état des lieux des performances énergétiques de constructions en pierres naturelles dans le contexte de la RE2020
« Natural stone in a context of environmental regulatory evolution of the construction, study of heat and moisture transfers in building envelope components ».In the context of French and international energy transition, the construction sector remains one of the most impacting on the environment and must evolve to limit the consequences. In response, the State has set up an experimentation, "positive energy building and carbon reduction", foreshadowing future thermal regulations for buildings, which will also become environmental (LCA).Most natural, local, and minimally processed materials have undeniable environmental advantages and the local sectors from which they come have interesting economic and social potential. These materials can then be perfectly integrated into a sustainable development approach. However, it is essential to know their physical behavior in order to be able to optimize their use in efficient, healthy, comfortable and durable constructions.The objective of this research is to develop massive natural stone for the construction of energy efficient and environmentally friendly buildings.A dozen rock samples were characterized from a thermal point of view (thermal resistance and thermal capacity), from a hydric point of view (absorption of water at atmospheric pressure, permeability to water vapor, water buffer, and hygroscopic sorption/desorption) and an environmental point of view (life cycle analysis of stone masonry). The experimental results obtained, in addition to the database of the Technical Center for Natural Building Materials, made it possible to carry out statistical studies on natural limestone. The prospects would be to estimate their physical characteristics and integrate them into developing building information modeling (BIM) modules.The hygrothermal properties of stones were also used as input data to study the coupled heat and mass transfers at several scales, from the wall to the building. The digital approach was compared to experimental approaches (bi-climatic chamber and in-situ instrumentation of a villa). The objective is to validate the numerical models used and the results of the characterization in the laboratory. Finally, a comparative dynamic thermal simulation study makes it possible to draw up an inventory of the energy performance of natural stone constructions in the context of the new regulation “RE2020”
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13

Foucher, Marion. "La pierre et les hommes en Bourgogne : archéologie et histoire d'une ressource en oeuvre du Moyen-Âge à l'époque moderne". Thesis, Dijon, 2014. http://www.theses.fr/2014DIJOL034/document.

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Pour dépasser les limites inhérentes à la déconnexion des disciplines ou celles imposées par les sources, les périodes ou les sites, cette thèse propose une approche pluridisciplinaire et diachronique de la question de l'approvisionnement en pierre des chantiers médiévaux et modernes. Grâce à la confrontation de bâtiments d'origines et de fonctions différentes, ce travail cherche à décortiquer les processus de choix et réseaux d'approvisionnement en pierre, pour envisager le rapport des hommes à une ressource naturelle
In order to go further limits inherent to subject disjunction, or those imposed by sources, periods or sites, this thesis emphasises a multidisciplinary and diachronic approach of stone supply on medieval and modern building sites. Thanks to the confrontation of buildings with different origins and functions, this work tries to dissect process of choices and stone supply network. It finally considers connection between people and a natural ressource
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14

Esteves, Luís Avelino Roque. "Pedras naturais portuguesas: o futuro prepara-se hoje". Master's thesis, Instituto Superior de Economia e Gestão, 2007. http://hdl.handle.net/10400.5/804.

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Mestrado em Gestão e Estratégia Industrial
O sector das pedras naturais tem longa tradição técnica e comercial no nosso País. Nas últimas dezenas de anos as empresas viveram um período de negócios florescente, com forte participação no mercado internacional, concorrendo com as potências do ramo, nomeadamente a Itália e a Espanha com base numa estratégia baseada em preços mais baixos para semelhante valor da pedra ou da obra acabada. Nos últimos anos, contudo, surgiu uma ameaça muito forte, consubstanciada na forte globalização do mercado e na entrada em cena do grupo BRIC. Numa primeira fase a sua capacidade tecnológica era limitada, mas de forma muito rápida adquiriram “know-how” e atingiram um nível de qualificação técnica que lhes permitiu tornarem-se numa ameaça muito séria. Sendo certo que a concorrência através da produção em massa e do baixo preço nos está definitivamente vedada, há que procurar uma via para saír do cerco que nos é feito pelos países de tecnologia mais evoluída e preço mais remunerador e pelos países da produção em massa. Parece, assim, ser imperioso definir uma estratégia que passe pela melhoria da nossa competitividade. Tentando dar um contributo válido para a resolução do problema e deixando de parte os aspectos ligados à estratégia, ao marketing e à comercialização, já estudados em outros trabalhos, resolvemos abordar o problema do incremento da nossa capacidade competitiva, com base no aumento da produtividade industrial, através da melhoria dos métodos de trabalho e de gestão da qualidade.
The Portuguese natural stones sector has a long technical and commercial tradition. During the last decades our companies faced a period of excellent turnovers, with a strong participation in the international market, competing with the most powerful countries in the sector, namely Italy and Spain. They have been using a strategy based on lower prices for the same level of offer either in terms of stone or final works. During 90’s a severe threat darkened our horizon and was intensified by the global market trends especially because the BRIC group came into it using very strong arguments. In the first stage its technical capacity was limited but in a short term they became a very serious threat after reaching a high level of qualification. The Portuguese companies are perfectly aware that they can’t go into the market using low prices and mass production anymore. A different approach must be found in order to overcome the sandwich they are being squeezed in between the most advanced countries and this last group. It seems the only possible option is to define a new strategy based on the use of the “best practices” to improve the quality and the value of their solutions. In order to give a valid input to solve this problem and trying to avoid aspects such as strategy, marketing and trading, dully analysed by some other authors, we decided to study the possibility of increasing our competitiveness. This increase must result from the productivity growth based on better working methods and quality management.
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15

Abu, Zaher Hana. "Removal of fluoride from spent potliner contaminated groundwater using reactive geomaterials". Thesis, 2015. http://hdl.handle.net/1959.13/1296463.

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Research Doctorate - Doctor of Philosophy (PhD)
Contamination of groundwater with fluoride has received worldwide attention due to its associated health problems with the prolonged intake of elevated fluoride concentration above 1.5 mg/L. This thesis dealt with the remediation of highly contaminated groundwater with the spent potliner leachate (SPLL) which is characterized by high concentration of fluoride among a cocktail of other chemicals (anions, cations, heavy metals and organics). The viability of natural calcite (limestone) and natural zeolite (clinoptilolite) for fluoride removal associated with SPLL was tested. The purpose was to find the optimal mixture of calcite and zeolite that will maximise fluoride removal and stop/or minimise the inhibitory effect of SPLL chemicals on calcite capacity to remove fluoride. Four calcite-zeolite mixtures were used, that is calcite, zeolite, calcite-zeolite (50:50) and calcite-zeolite (70:30). The removal capacity of these mixtures in batch and column tests was not the same. For a long residence (contact) time (as in batch tests), more fluoride was removed by calcite-zeolite 50:50 and 70:30 mixtures than calcite or zeolite alone. That was true for both synthetic and SPLL solutions. In continuous column tests (where the contact between fluoride and sorbents is spatial and temporal), SPLL tests showed a prevalence of zeolite over calcite or its mixtures (calcite-zeolite 50:50 and 70:30). For synthetic fluoride solution, all columns containing zeolite showed nearly similar fluoride removal which was higher than that obtained using column containing calcite. Overall, in batch tests calcite showed better fluoride removal than zeolite while the inverse was true in column tests. That was attributed to the fact that zeolite has more surface area than calcite and moreover the removal mechanism of fluoride by calcite depends on the slow hydrolysis process. Hence calcite is more effective in batch tests setup where enough time is allowed for calcite dissolution. Fluoride removal by calcite and zeolite was depleted in SPLL by ~40-67% in 1.18 mm and ~12-46% in 150 µm fraction sizes as compared to synthetic fluoride solution. Heavy metals (lead, magnesium and manganese) and organics (3-methylphenol and 4-methylphenol) associated with fluoride in SPLL showed an interfering effect for fluoride removed by calcite. Other major heavy metals (vanadium, copper, barium and cobalt) and organics (aniline, phenol, 2-methyl phenol, 2-methylnaphthalene, acenaphthene, fluorene and carbazole) in SPLL solution have not shown any effect on calcite capacity to remove fluoride.
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16

Winter, Maria-Barbara. "Natürliche Waldentwicklung unter dem Einfluss des Borkenkäfers im Nationalpark Berchtesgaden". Thesis, 2016. http://hdl.handle.net/11858/00-1735-0000-0028-8796-2.

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Störungen sind ein integraler Bestandteil von Waldökosystemen. Von einzelbaumweiser Seneszenz bis hin zu großflächigem Windwurf, Waldbrand oder Insektenbefall prägen sie natürlicherweise Artenzusammensetzung, Generationswechsel und Verjüngungsprozesse von Waldbeständen. Aufgrund wirtschaftsbedingt hoher Anteile an sekundären reinen Nadelholzbeständen und sich ändernden klimatischen Bedingungen ist der Einfluss großflächiger Störungen im letzten Jahrhundert in Mitteleuropa angestiegen und wird vermutlich auch zukünftig weiter an Bedeutung gewinnen. Das ökosystemare Verständnis über die Wirkung dieser Störungsereignisse auf Artenzusammensetzung und natürliche Waldentwicklung ist wesentlich für eine nachhaltige Waldbewirtschaftung. Im Wirtschaftswald kann der Einfluss natürlicher Störungen aufgrund stetiger Einflussnahme durch Räumung, Pflanzung und Durchforstungen schwerlich untersucht werden. Großflächige Schutzgebiete mit dem Prozessschutz dienenden unbewirtschafteten Kernzonen bieten hingegen diese Möglichkeit. Am Beispiel des Nationalparks Berchtesgaden im südlichen Oberbayern (Deutschland) wurde daher exemplarisch für die Nördlichen Kalkalpen die natürliche Waldentwicklung unter dem Einfluss des Borkenkäfers und die Veränderungen von Bestandesstrukturen und Biodiversität im Verlauf von Störung und Sukzession untersucht. Durch den großen Holzbedarf der regional ansässigen Salinenindustrie ab dem 16. Jahrhundert, der jahrhundertelangen Kahlschlagswirtschaft und den hohen Wilddichten im Bayerischen Hofjagdgebiet wurden die natürlicherweise in den montane Lagen stockenden Bergmischwälder aus Europäischer Buche, Weißtanne und Gemeiner Fichte in überwiegend reine, sekundäre Fichtenwälder umgewandelt. Seit Einrichtung des Nationalparks Berchtesgaden 1978 kam es besonders nach den Winterstürmen Vivian/Wiebcke 1990 und Kyrill 2007 zu stärkerem Borkenkäferbefall. Luftbildauswertungen belegen ein zerstreutes und eher kleinflächiges Befallsgeschehen außerhalb des Maßnahmenbereichs Borkenkäferbekämpfung. Mittlere Befallsflächengrößen lagen bei 0,07 ha (1990-1997) und 0,29 ha (2007-2012); die Gesamtbefallsflächen betrugen 30 ha (1990-1997) und 260 ha (2007-2012). Mit der Methodik einer unechten Zeitreihe konnte auf 140 Probeflächen die Entwicklung unbefallener Fichtenaltbestände über das beginnende frühsukzessionale Stadium (1-5 Jahre nach Borkenkäferbefall) hin zum fortgeschrittenen frühsukzessionalen Stadium (17-25 Jahre nach Borkenkäferbefall) von montaner bis subalpiner Höhenstufe in sonn- und schattseitigen Lagen erfasst werden. Das Absterben der Fichtenaltbestände durch den Borkenkäferbefall führte zu einer signifikanten Reduktion der Bestandesvolumina und der Kronenüberschirmung auf den Befallsflächen bei gleichzeitig massiver Zunahme an stehendem Totholz. Erhebliche Anteile des stehenden Totholzes brachen bei fortschreitender Zersetzung im Verlauf der untersuchten etwa 20-jährigen Sukzession zusammen. Humusabbau und signifikante Veränderungen des Mesoklimas durch die Störung waren nicht nachzuweisen. Die durch das Absterben des Kronendachs erhöhten Anteile an direkter Strahlung am Waldboden führten zu einer zunehmenden Deckung und Höhe der Bodenvegetation. Trotz der verstärkten Konkurrenzsituation mit der Bodenvegetation kam es, besonders in montaner Lage, zu einer zügigen Verjüngung der Befallsflächen mit Jungwuchsdichten von im Median rund 5.000 Pflanzen > 50 cm Höhe und weiteren etwa 5.000 Pflanzen < 50 cm Höhe pro Hektar, zwei Jahrzehnte nach dem Borkenkäferbefall. Hochmontan war diese Entwicklung verzögert zu beobachten. Hier nahm Bedeutung des Totholzes als Keim- und Wuchssubstrat mit zunehmender Zersetzung zu. Der Jungwuchs wurde von Gemeiner Fichte, Bergahorn und Vogelbeere dominiert. Die natürlichen Hauptbaumarten des Bergmischwaldes – Europäische Buche und Weißtanne – fehlten jedoch aufgrund der historischen Bewirtschaftung und mangelnden Samenbäumen auch im Jungwuchs weitgehend. Die Störung führte unter anderem durch das räumlich unregelmäßige Aufkommen des Jungwuchses zu einer erhöhten strukturellen Heterogenität auf Bestandes- und Landschaftsebene. Entgegen der Erwartungen spielte die Vorausverjüngung für die Verjüngung nach dem Störungsereignis eine vernachlässigbar geringe Rolle. Mehr als 90 % der Jungwuchsindividuen waren nach dem Störungsereignis gekeimt und bestätigten damit eine große Resilienz der Bergwälder nach mittelgroßen Störungsereignissen unter der Voraussetzung angepasster Schalenwildbestände. Bei den untersuchten epigäischen Artengruppen waren keine Veränderungen (Käfer, Spinnentiere, Mollusken), bzw. ein Rückgang der Artenvielfalt (Springschwänze) aufgrund fehlender Streunachlieferung nach der Störung zu beobachten. Die licht-, nährstoff- und totholzbedürftigen Arten profitierten hingegen von den temporären Lückenbedingungen und reagierten überwiegend mit einem Anstieg der Artenvielfalt im Verlauf der Sukzession. Dieser Anstieg war auch zwei Jahrzehnte nach dem Störungsereignis trotz zunehmender Verjüngungsdichten noch zu beobachten. Dies verdeutlicht die Relevanz von sich langsam schließenden Bestandesöffnungen für eine vollständige Entwicklung der Biodiversität heliophiler Artengruppen in Waldökosystemen. Durch das Mosaik verschiedener, kleinräumig verbreiteter Sukzessionsstadien auf Landschaftsebene zeigten besonders die totholzbesiedelnden Pilze und Käfer eine hohe Gamma-Diversität im Gebiet. Die Artengemeinschaften der Gefäßpflanzen ähnelten sich hingegen stark in ihrer Artenzusammensetzung in den drei untersuchten Sukzessionsstadien und zeichneten sich mehr durch eine Verschiebung der Dominanzverhältnisse aus.   Räumung und Pflanzung auf Befallsflächen innerhalb des Maßnahmenbereichs Borkenkäferbekämpfung führten im Vergleich zu den unbehandelten Befallsflächen nicht zu einer Erhöhung der Jungwuchsdichten im beginnenden frühsukzessionalen Stadium, aber zu einer Steigerung der Anteile an Weißtanne und Europäischer Buche im Jungwuchs. Mollusken, Wanzen und bestäubende Käferarten reagierten auf die tendenziell höheren Strahlungsmengen am Waldboden und zeigten höhere Artenzahlen auf den geräumten Flächen. Zeitgleich veränderte die Räumung des befallenen Totholzes die Artenzusammensetzung vieler der untersuchten Artengruppen und reduzierte die Artenvielfalt der xylobionten Käfer. Der forstlichen und naturschutzfachlichen Praxis wird aus den Ergebnissen dieser Untersuchung heraus empfohlen, die durch natürlichen Störungen entstandenen Lücken und Strukturen zu nutzen, um den Erhalt von licht-, nährstoff- und totholzbedürftigen Artengruppen zu fördern und, soweit aus Gründen des Lawinen- und Forstschutzes möglich, auf Räumung und direkte Bepflanzung der Flächen zu verzichten. Wo es das Ziel ist, die natürliche Baumartenzusammensetzung der Bergmischwälder kurzfristig wieder herzustellen, müssen Buche und Tanne bei einem Mangel an Samenbäumen künstlich eingebracht werden. Ansonsten weisen die im Gebiet stockenden Bergwälder unter der Voraussetzung angepasster Wildbestände bei mittelgroßen Störungsereignissen eine große Resilienz auf und lassen ein Schließen der Bestandeslücken durch Naturverjüngung erwarten.
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17

Kozlovcev, Petr. "Vliv mineralogického složení suroviny na vznik fází při výpalu hydraulického vápna a přírodního cementu". Doctoral thesis, 2018. http://www.nusl.cz/ntk/nusl-383076.

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Natural hydraulic lime and natural cement have been used in the building industry for centuries. These inorganic hydraulic binders are called "traditional" or "alternative" because they can, in some cases, substitute modern Portland cement. The recent increased interest in these binders is due not only to their use in restoration practices, but also because their production and use is less energetically demanding than in modern cements. Historically, many types of hydraulic binders were produced in the regions of Bohemia and Moravia. However, much information has been lost about their manufacturing process, which raw materials were used, and we are uncertain of the exact character and properties of the burned material. To date, studies have only addressed the impact of the chemical composition of raw material on the parameters of the burned material - all this is well known for Portland cement, much less for other types of hydraulic binders. The aim of this dissertation was to study the various types of raw materials (limestone containing non- carbon admixtures) and to understand the characteristics of their respective hydraulic lime and natural cement. This was done by analyzing the impact of conditions (highest achieved burning temperature and time of burning) and the mineral and chemical...
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18

Kozlovcev, Petr. "Experimentální výzkum paleozoických vápenců barrandienské oblasti s ohledem na jejich možné využití pro výpal hydraulických vápen a přírodního cementu". Master's thesis, 2012. http://www.nusl.cz/ntk/nusl-309342.

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54 Summary In this experimental study, selected Devonian limestones of the Prague Basin (i.e. samples from the historic quarry of Branické skály) were examined to find their suitability for production of hydraulic limes or for natural cement. Four representative samples of the dvorecko-prokopské limestone were sampled in the form of blocks weighing approximately 10 kg each, from the layer of the quarry wall that had been chosen based on literature research. A detailed mineralogical-petrographic examination of samples was the first step, in an attempt to obtain their mineralogical composition, microstructure and texture. Samples were analysed by polarizing microscopy and cathodoluminescence of thin sections, and X-ray diffraction of insoluble residues determined by treatment with both the hydrochloric acid and the acetic acid solution. Mineralogical composition of the insoluble residuals was illite, kaolinite, quartz and Na-plagioclase (albite). Two samples contained among above mentioned mineral phases also chlorite. The utility of studied limestones for the production of hydraulic binders (hydraulic limes and natural cement) was derived from both the calculations based on obtained chemical analyses (included standard cement and lime indexes and modules) and the firing experiments. The firing experiments...
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19

Antunes, João Trovão Lima Simões. "The role of fungi on monumental stone biodeterioration within the UNESCO World heritage site of “University of Coimbra– Alta and Sofia”". Doctoral thesis, 2021. http://hdl.handle.net/10316/96434.

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Tese no âmbito do Doutoramento em Biociências, especialização em Biologia Celular e Molecular, orientada pelo Professor Doutor António Manuel Santos Carriço Portugal, Professor Doutor Francisco Paulo de Sá Campos Gil, Doutor Igor Clemente Tiago e apresentada ao Departamento de Ciências da Vida da Faculdade de Ciências e Tecnologia da Universidade de Coimbra.
Among the distinct microbial populations able to grow in stone monuments, colonization by fungi often results in severe aesthetic, physical and chemical biodeterioration of the substrate. This multidisciplinary thesis attempts to understand the biodeteriorative role of fungal communities thriving in stone monuments present within the UNESCO World heritage site of “University of Coimbra- Alta and Sofia”. Accordingly, this work aims were: (1) to produce a detailed inventory characterizing fungal communities using both classical and -omics approaches in key monuments in this area; (2) to describe novel fungal taxa colonizing these supports; (3) to link the detected fungal species, environmental and stone petrochemical characteristics with the observed deterioration processes; (4) to assess fungal biodeteriorative potential and the studied limestone bioreceptivity; and (5) to evaluate and develop control procedures targeting specific harmful biodeteriorating fungal species. This comprehensive research is started with a set of studies aiming to identify the fungal species and their deteriorative action, in various biodeterioration outlines present in the dolomitic limestone walls of the Old Cathedral of Coimbra. The combined approach using traditional cultivation methodologies coupled with modern Next Generation Sequencing techniques, allowed to identify the fungal communities present in this monument, while also allowing to verify that in similar studies their joined application is advised. During this survey, isolates from an unknown microcolonial black fungal species were retrieved. In order to understand this species taxonomic status, a polyphasic study was conducted, allowing the description of a new family, Aeminiaceae fam. nov., a new genus Aeminium gen. nov., and a new species, Aeminium ludgeri sp. nov. Moreover, considering the significance of this finding and in order to explore gene content and genomic traits, the species genome was also sequenced and thoroughly studied. Several distinctive traits that putatively contribute to the organism extremotolerance and biodeteriorative profile were thus highlighted. In order to further understand fungal dolomitic limestone bioreceptivity and biodeterioration, an extensive analysis aiming to identify biodeteriorative abilities and limestone bioreceptivity to fungi thriving in this site was then conducted. The results showed that a significant number of the tested species contributed to dolomitic limestone biodeterioration and that fungal proliferation was slightly superior in oligotrophic rather than copiotrophic conditions. In the ensuing section, attention is given to a series of studies focusing in the biodeteriorative effects of the proliferation of fungal communities in the relieves adorning the Ançã limestone tomb of the First Portuguese King. A multi-disciplinary approach to fully characterize these phenomena allowed to verify a massive fungal diversity and abundance in this monument, while also pinpointing that the establishment of differential fungal populations coupled with the deposition of environmental particles contributed to the development of the distinct phenomena by various mechanisms. In order to further study Ançã limestone fungal bioreceptivity and biodeterioration, an experimental laboratorial analysis was also carried out. The results revealed that all tested species contributed to the substratum biodeterioration and that Penicillia growth was favored in rich micro-nutrient environments, while Aspergilli and Aeminium ludgeri denoted a slightly more accentuated growth under depleted nutrient conditions. Subsequently, focus is then given to the fungal communities thriving in the Coimbra Roman cryptoporticus and in particular to the presence of whitish mold-like propagations in some areas of this site. Fearing that a putative fungal outbreak could be taking place, the fungal communities in these sites were deeply characterized. The results revealed that these propagations are a result of Lecanicillium psalliotae proliferations and that possible outbreaks by this species are putatively occurring through animal vectored dispersion. In the penultimate section of this thesis, the main advantages of cultivation approaches are highlighted, with the description and biodeteriorative profiling of several unknown filamentous fungal taxa retrieved from the studied monuments. Moreover, one of the species described, exhibited a very high ability to induce the formation of calcium oxalates in vitro, a deteriorative profile that would never be noted, if solely the use of Next-generation sequencing methodologies was considered. Lastly, considering the ongoing efforts to restore and preserve various monuments in this UNESCO area, the final focus in then given to test the in vitro efficiency of chemical biocides previously used in the University tower against various fungal species retrieved during the course of this thesis. Moreover, they were also compared with an increasing attractive green option, Ocimum basilicum essential oil. Altogether, the scientific information developed and gathered during the course of this thesis provides a massive update concerning the current knowledge on fungal limestone interactions and biodeterioration, while also providing a strong evaluation of the current methodologies applied to study them in similar contexts.
Entre as distintas populações microbianas capazes de crescer em monumentos rochosos, a colonização por fungos frequentemente resulta numa severa biodeterioração estética, física e química do substrato. Esta tese multidisciplinar procura compreender o papel biodeteriorativo das comunidades de fungos que prosperam em monumentos de pedra presentes no património mundial da UNESCO da “Universidade de Coimbra-Alta e Sofia”. Assim, os objetivos deste trabalho foram: (1) produzir um inventário detalhado caracterizando as comunidades de fungos, usando para isso abordagens clássicas e -ómicas em monumentos-chave nesta área; (2) descrever novos taxa de fungos que colonizam estes suportes; (3) relacionar as espécies de fungos detectadas, as características ambientais e petroquímicas da rocha com os processos de deterioração observados; (4) avaliar o potencial biodeteriorativo dos fungos e a sua bioreceptividade nos calcários estudados; e (5) avaliar e desenvolver procedimentos de controlo visando espécies específicas de fungos biodeterioradores prejudiciais. Esta abrangente investigação inicia-se com um conjunto de estudos que visam identificar as espécies fúngicas e a sua ação deterioradora nos diversos perfis de biodeterioração presentes nas paredes calcárias dolomíticas da Sé Velha de Coimbra. A abordagem combinada utilizando metodologias de cultivo tradicionais aliadas a modernas técnicas de Sequenciamento de Próxima Geração, permitiu identificar as comunidades fúngicas presentes neste monumento, permitindo também verificar que em estudos semelhantes é aconselhável a sua aplicação conjunta. Durante esta pesquisa, isolados de uma espécie desconhecida de fungo microcolonial negro foram recuperados. Com o objetivo de compreender o status taxonómico desta espécie, foi realizado um estudo polifásico, permitindo a descrição de uma nova família, Aeminiaceae fam. nov., um novo género Aeminium gen. nov., e uma nova espécie, Aeminium ludgeri sp. nov. Além disso, considerando a importância desta descoberta e com o fim de explorar o conteúdo genético e as suas características genómicas, o genoma da espécie foi também sequenciado e estudado exaustivamente. Vários traços distintivos que putativamente contribuem para a extremotolerância do organismo e o seu perfil biodeteriorativo foram assim destacados. A fim de compreender melhor a bioreceptividade e a biodeterioração do calcário dolomítico por espécies fúngicas, foi realizada uma extensa análise com o objetivo de identificar as suas habilidades biodeteriorativas e a bioreceptividade do calcário a fungos que prosperam neste local. Os resultados mostraram que um número significativo das espécies testadas contribuiram para a biodeterioração do calcário dolomítico e que a proliferação de fungos foi ligeiramente superior em condições oligotróficas do que copiotróficas. Na secção seguinte, é dada atenção a um conjunto de estudos que incidem sobre os efeitos biodeteriorativos da proliferação de comunidades fúngicas nos relevos que adornam o túmulo de calcário de Ançã do Primeiro Rei Português. Uma abordagem multidisciplinar para caracterizar completamente esses fenómenos permitiu verificar uma enorme diversidade e abundância de fungos neste monumento, ao mesmo tempo que apontou que o estabelecimento de populações diferenciais de fungos, juntamente com a deposição de partículas ambientais, contribuíram para o desenvolvimento dos distintos fenómenos por vários mecanismos. Com o objetivo de aprofundar o estudo da bioreceptividade e biodeterioração fúngica do calcário de Ançã, foi realizada uma análise laboratorial experimental. Os resultados revelaram que todas as espécies testadas contribuíram para a biodeterioração do substrato e que o crescimento de Penicillia foi favorecido em ambientes ricos em micronutrientes, enquanto Aspergilli e Aeminium ludgeri denotaram um crescimento ligeiramente mais acentuado em condições de depleção de nutrientes. Posteriormente, o enfoque é dado às comunidades de fungos que prosperam no criptopórtico Romano de Coimbra e, em particular, à presença de propagações esbranquiçadas semelhantes a fungos em algumas áreas deste local. Temendo que um possível surto fúngico pudesse estar a ocorrer, as comunidades de fungos nesses locais foram profundamente caracterizadas. Os resultados revelaram que essas propagações são resultado da proliferação de Lecanicillium psalliotae e que possíveis surtos por esta espécie estão a ocorrer putativamente por meio de dispersão vetorial animal. Na penúltima seção desta tese, as principais vantagens das abordagens de cultivo são destacadas, com a descrição e a caracterização do perfil biodeteriorativo de vários taxa de fungos filamentosos desconhecidos e recuperados dos monumentos estudados. Além disso, uma das espécies descritas, exibiu uma capacidade muito elevada de induzir a formação de oxalatos de cálcio in vitro, um perfil de deterioração que nunca seria notado se apenas o uso de metodologias de sequenciamento de próxima geração fosse considerado. Por último, considerando os esforços em curso para restaurar e preservar vários monumentos nesta área da UNESCO, o enfoque final é então dado na testagem da eficácia in vitro de biocidas químicos anteriormente utilizados na torre da Universidade contra várias espécies de fungos recuperadas no decorrer desta tese. Além disso, eles também foram comparados com uma opção verde cada vez mais atraente, o óleo essencial de Ocimum basilicum. No seu conjunto, a informação científica desenvolvida e recolhida ao longo desta tese, fornece uma atualização maciça sobre o conhecimento atual sobre as interações e biodeterioração do calcário fúngico, ao mesmo tempo que fornece uma forte avaliação das metodologias atuais aplicadas para estudá-los em contextos semelhantes.
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