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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.
1

Water in archaeological wood : a critical appraisal of some diagnostic tools for degradation assessment

Ogilvie, Ticca Margaret Alison January 2000 (has links)
No description available.
2

Současný stav a historický vývoj podmáčených luk na Říčansku / Current condition and historical development of waterlogged meadows in the region of Říčany

Horina, Lukáš January 2010 (has links)
During a cooperation on a project of the orchid protection in the Říčany Ecocenter number of questions arose. Firstly it is a question of an identification of orchid meadows. Then finding main parameters of an environment, which influence the occurence of Dactylorhiza majalis. Consequently finding factors that influence the size of population of Dactylorhiza majalis. And eventually finding a suitable management for the orchid meadows. I was trying to find the answers mainly via a comparison of orchid and similar non orchid meadows. I was comparing species composition, local conditions and historical use of the site. I decided for the method of phytocenologic snaps and Ellenberg numbers for detection of the local conditions. Historical maps were used for finding the historical use. Data were processed by statistic analytical methods (PCA,RDA) When comparing orchid and non orchid meadows I found out that they differ conclusively in species composition and in number of species. I found plant species according to which it is possible to determine a potentional orchid location. Furthermore I found out that orchid and non orchid meadows differ in values of parameters of an environment. Consequently I found that these parameters are continentality, humidity and trophy of the site. Then I found out that humidity...
3

Re-conservation of Wood from the Seventeenth-Century Swedish Warship the Vasa with Alkoxysilanes: A Re-treatment Study Applying Thermosetting Elastomers

Cabrera Tejedor, Carlos 2010 December 1900 (has links)
The purpose of this study was to explore the feasibility of re-treating artifacts previously conserved by PEG impregnation with alkoxysilanes. The study tried to evaluate pros and cons of re-conserving artifacts with this type of silanes. A series of experiments were conducted focusing on small, wood samples from the Vasa Museum Collection, to test different re-conservation methods. Three different procedures involving alkoxysilanes were implemented in order to re-conserve the samples. The study revealed the techniques are an efficient re-conservation method in which highly satisfactory results can be achieved. The re-treated samples present minimal volumetric distortion without significant collapse or shrinkage of the wood structures. This minimal distortion is primarily produced by the transition from swollen waterlogged wood to a dry conserved wood, and not as a result of collapse or shrinkage during treatment. Due to the negligible thickness of the polymer coating (a few microns), the samples acquire physical properties extremely close to the original dry wood. Moreover, other physiochemical properties are obtained from the consolidation with alkoxysilanes; the re-conserved wood becomes hydrophobic, chemically inert, resistant to chemical attacks (e.g., acids or bases), and resistant to ultraviolet light. These newly acquired characteristics drastically reduce the preventive conservation measures needed in museum display cabinets or during transport. Despite the excellent results, the procedure is not reversible, thus does not comply with one of the main premises traditionally accepted in conservation. Therefore, a careful study assessing benefits and disadvantages in a case-by-case basis should be assessed by conservators, restorers, and curators before applying this method to waterlogged material culture.
4

PEG含浸木材のGC/MSによる残存PEG測定

NAKAMURA, Toshio, NAKAMURA, Shinya, NISHIMOTO, Hiroshi, 中村, 俊夫, 中村, 晋也, 西本, 寛 03 1900 (has links)
第23回名古屋大学年代測定総合研究センターシンポジウム平成22(2010)年度報告
5

Effects of site preparation for afforestation on soil properties and greenhouse gas emission

Mojeremane, Witness January 2009 (has links)
Forest plantations in the UK are often established on seasonally waterlogged peaty gley soils which often require site preparation (drainage and mounding) to lower the water table and prepare planting positions. Substantial changes in the physical environment of peaty gley soils can accompany site preparation including fluctuations in soil temperature and soil moisture. These and other changes can all affect soil properties and decomposition processes and well as the dynamics of CO2, CH4 and N2O. A field experiment was established at Harwood Forest (NE England) to investigate the effects of three site management practices (drainage, mounding and fertilisation) frequently used for afforestation and replanting on peaty gley soils in the UK on soil properties and various of C and N, environmental variables (soil temperature, water content and water table height) and emissions of CO2, CH4 and N2O. The relationship between GHG emissions and environmental variables was also examined. The experiment was laid out in a factorial split-plot design. Drainage decreased C and N concentration in the 10 cm soil layer. The soil bulk density in the 0 to 20 cm soil layer was increased by mounding. Drainage and fertilisation increased soil CO2 efflux, whereas mounding did not affect soil CO2 efflux. All three practices affected soil CH4 fluxes with drainage reducing the fluxes and mounding and fertilisation increasing the fluxes. Nitrous oxide emissions were significantly affected by mounding and fertilisation, with mounding decreasing emissions and fertilisation increasing emissions. Soil temperature was the main environmental factor controlling soil respiration in this site. Over the two years study drainage and fertilisation increased the total greenhouse budget by 13.1% and 97.9%, while mounding caused a reduction of−17.6%. Drainage plus mounding reduced the total greenhouse budget by 6.9%, while drainage plus mounding plus fertilisation increased the total greenhouse budget by 101.8%. There is a potential for up-scaling GHG emissions from newly drained peaty gley for inclusion in the UK Land Use Land-Use Change and Forestry (LULUCF) Greenhouse Gas Inventory. However up-scaling and evaluation of the net emissions requires high quality data from different sites newly drained for afforestation. More studies are needed if net fluxes from newly drained sites are to the included in the LULUCF Greenhouse Gas Inventory.
6

Influência do alagamento nas formas e disponibilidade de fósforo em solo de várzea / Influence of flooding on the forms and availability of phosphorus in lowland soil

Silva, Juliana Brito da 29 April 2013 (has links)
Made available in DSpace on 2014-08-20T14:36:54Z (GMT). No. of bitstreams: 1 tese _ juliana_brito_da-silva.pdf: 1619365 bytes, checksum: 36ed1c221f405cdf4ddc99a9be585be7 (MD5) Previous issue date: 2013-04-29 / In irrigated rice, the lowland soils can supply the plants with different amounts of phosphorus due to the source material and the phenomenon that occur in different cycles of oxidation and reduction of these soils. An important factor which regulates the soil availability of phosphorus for plants is the ability to absorb phosphorus. With the overall objective of evaluating the effect of flooding on the forms of phosphorus and on the absorption capacity of phosphorus in lowland soils, two studies have been developed. In the first study, from two larger experiments, conducted for five years (2003/04 to 2007/08), in Solodic Planosol, three treatments have been selected: control, recommended dose of P2O5 as SFT + annual increase of replacement dose and dose Recommended P2O5 as FN + annual increase of replacement dose. Soil samples were collected at two depths (0-2,5 cm and 2,5-5,0 cm) in the respective treatments. The irrigated rice by flooding provides the decrease inorganic forms of labile soil P (RTA and bic 0.5 mol L-1), in the 0-2.5 cm layer in both restevas using the SFT. The form of P most affected by flooding was the one protected inside of microaggregates (Pi hid 0,5 mol L-1) on both stubbles and depths. Organic P had greater participation in total P using the SFT and FN, in both stubbles and depths, after flooding, followed by Pinorganic and finally, the P-residual. In the second study, conducted in the greenhouse, it was evaluated the effect of flooding in the maximum adsorption capacity of phosphorus - CMAP in two lowland soils (Planossolo Haplico and Chernossolo Ebanico), with different adsorption capacity of phosphorus-CMAP, low and high collected at a depth of 0-20 cm, conducted in a flooded and nonflooded structured in a 2x2 factorial design. The determination of CMAP was made by adjusting adsorption isotherm in which subsamples were placed in contact of increasing concentrations of P (1, 2, 4, 5, 10, 20, 30, 40, 50, 60, 70, 80, 100 and 125 mg kg-1 of P) for 16 h. After that, the P determined in equilibrium in the solution, and the Langmuir equation to the data set. After drainage the CMAP of the soil increased taking about 184 days to return to its initial condition before the flooding. The CMAP increases in flooded soil immediately after drainage, and this effect endures for at least 96 days after drainage. / No cultivo do arroz irrigado por alagamento, os solos de várzea podem suprir as plantas com diferentes quantidades de fósforo devido ao material de origem e aos fenômenos que ocorrem nos diferentes ciclos de oxidação e redução. Um fator importante do solo que regula a disponibilidade do fósforo para as plantas é a capacidade de adsorção de fósforo. Com o objetivo de avaliar o efeito do alagamento sobre as formas de fósforo e sobre a capacidade de adsorção de fósforo em solos de várzea desenvolveram-se dois estudos. No primeiro estudo, a partir de dois experimentos mais amplos, conduzido por cinco anos (2003/04 a 2007/08), em um Planossolo Háplico eutrófico solódico, foram selecionados três tratamentos: testemunha sem adição de P2O5, dose recomendada de P2O5 na forma de superfosfato triplo- SFT (110 kg ha-1 para o milho e 120 kg ha-1 para a soja) + acréscimo anual da dose de reposição e dose recomendada de P2O5 na forma de fosfato natural de Arad (FN) + acréscimo anual da dose de reposição. No quinto ano do experimento foram coletadas amostras de solo das parcelas experimentais em duas oportunidades (0-2,5 e 2,5- 5,0 cm), antes e após o cultivo do arroz, onde foi realizado o fracionamento químico de fósforo. O cultivo de arroz irrigado por alagamento propicia a dimimuição das formas inorgânicas lábeis de P no solo (RTA e bic 0,5 mol L-1), na camada de 0-2,5 cm em ambas as restevas, utilizando o SFT. A forma de P mais afetada pelo alagamento foi aquela protegida no interior dos microagregados (Pi hid 0,5 mol L-1) em ambas as restevas e profundidades. O P orgânico teve maior participação no P total utilizando o SFT e o FN, em ambas as restevas e profundidades, após o alagamento, seguido do P-inorgânico e por último, do Presidual. No segundo estudo, conduzido em casa de vegetação, avaliou-se o efeito do alagamento na capacidade máxima de adsorção de fósforo CMAP de dois solos de várzea (Planossolo Háplico eutrófico solódico e Chernossolo Ebânico carbonático vértico) com diferente capacidade de adsorção de fósforo- CMAP, baixa e alta coletados na profundidade de 0-20 cm, conduzidos de forma alagada e não-alagada estruturada em um fatorial 2x2. A determinação da CMAP foi feita por meio do ajuste de isotermas de adsorção, em que subamostras foram colocadas em contato com concentrações crescentes de P (1, 2, 4, 5, 10, 20, 30, 40, 50, 60, 70, 80, 100 e 125 mg kg-1 de P no solo) durante 16 h. Após esse período, determinou-se o P em equilíbrio na solução, sendo a equação de Langmuir ajustada aos dados. A CMAP aumenta em solos alagados imediatamente após a drenagem, sendo que este efeito pendura por pelo menos 96 dias após a drenagem
7

Approvisionnement et usages du bois en Auvergne, du Second âge du Fer au Moyen Âge / Supply and uses of wood in Auvergne, from the Iron Age in the Middle Ages

Blondel, François 10 December 2018 (has links)
Les bois gorgés d’eau sont des découvertes rares en archéologie, du fait des conditions inhérentes à leur conservation. Quand ils nous parviennent, ils livrent de nombreuses données sur la place de ce matériau pour les populations anciennes.L’Auvergne est un contexte privilégié pour leur conservation. Des milliers de bois issus de découvertes fortuites ou de fouilles archéologiques sont datés du Néolithique à l’époque moderne, mais le corpus couvre surtout le Second âge du Fer jusqu’au Moyen Âge.La diversité des bois permet d’appréhender les différents usages selon leur destination respective. Le bon état de nombreux éléments renseigne de différentes étapes de façonnage de l’abattage de l’arbre à sa mise en œuvre.Chaque bois est détaillé spécifiquement par domaine et catégorie pour être comparé aux vestiges d’autres régions. L’approche technologique et typologique est traitée le plus exhaustivement possible.Le spectre taxonomique renseigne les pratiques de collecte et leur évolution sur un espace forestier impacté par l’homme.L’apport de la dendrochronologie renseigne les évolutions des approvisionnements, principalement pour la construction, et dégage certains traits des pratiques sylvicoles sur les peuplements forestiers exploités. / Waterlogged woods are rare discoveries in archeology because of the conditions inherent in their conservation. When they reach us, they give a lot of data on the importance of this material for past populations.Auvergne is a privileged context for their conservation. Thousands of woods from fortuitous discoveries or archaeological excavations are dated from the Neolithic to the modern era, however the corpus covers mostly the Second Iron Age until the Middle Ages.The diversity of the woods enables a better understanding of different uses according to their respective destination.The state of conservation of many elements gives information about the different stages of shaping, from the felling of the tree to its implementation.Each wood is detailed specifically by field and category to be compared with the remains of other regions. The technological and typological approach is treated as exhaustively as possible.Taxonomic diversity documents collection practices and their evolution in a forest area impacted by humans.The contribution of dendrochronology informs the evolutions of supplies, mainly for the construction, and releases certain features of the silvicultural practices in the exploited forest stands.
8

Study on conservation of archaeological waterlogged wood in Vietnam / ベトナムの遺跡出土木材の保存に関する研究

Nguyen, Duc Thanh 23 May 2018 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第21277号 / 農博第2293号 / 新制||農||1062(附属図書館) / 学位論文||H30||N5141(農学部図書室) / 京都大学大学院農学研究科森林科学専攻 / (主査)教授 杉山 淳司, 教授 吉村 剛, 教授 渡邊 隆司, 教授 高妻 洋成 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM
9

Det perfekta rörbladet: ett resultat av slumpen, modifiering eller metodiskt urval? : Ett examensarbete i inspelningsmetodik och arbetet kring rörblad / The perfect reed: The result of modification, methodical choice, or a coincidence? : A study in methods of breaking in reeds and the work around modifying them

Lager Penalvert, Jan January 2022 (has links)
Syftet med detta examensarbete var att utforska olika sätt att spela in rörblad samt att modifiera mina klarinettrörblad, och utveckla en djupare förståelse för vilka metoder som fungerade bäst för mig. Målet var att kunna känna trygghet i mina rörblads förmåga att producera önskvärd klang, så att jag gav mig själv så bra förutsättningar som möjligt rörbladsmässigt inför framtida konserter. Projektet genomfördes under en 8 månaders period, september 2021 till maj 2022 och bestod av inspelning av 12 askar rörblad och modifiering av de rörblad som inte gav önskat resultat. För modifieringen användes främst Peter Hadcocks metoder, och då undersöktes hur bra dessa fungerade för mig. Resultatet visade att en metodisk inspelning gav mer långlivade rörblad som inte tappade kvalitet lika fort som kontrollrörbladen. Resultatet visade också att det fanns en relevant möjlighet till modifiering av de rörblad som inte var bra nog, så att de efter modifiering var bra nog att användas. Livslängden gick också att förlänga till viss del genom modifiering. / The purpose of this study was to explore different methods for breaking in and modifying clarinet reeds, and to develop a deeper understanding of which methods work best for me. The goal was to be able to feel security in the ability to produce the desired sound and timbre from my reeds, so that I could give myself the best conditions that were possible, reed wise, before future concerts. The project was carried out over an 8- month period, September 2021 to May 2022 and consisted of breaking in 12 boxes of reeds and modifying the ones that didn’t give the desired result. Peter Hadcock’s methods for modifying reeds were used during the study, and I investigated how well they work for me. A methodic break in process resulted in long-lived reeds that didn’t loose their quality as fast as the control group. The result also showed that there was a possibility to modify the undesired reeds to make them playable. The life expectancy of good reeds could also be extended through modification.
10

Fourier-transform Raman spectroscopic study of a Neolithic waterlogged wood assemblage

Petrou, M., Edwards, Howell G.M., Janaway, Robert C., Thompson, Gill B., Wilson, Andrew S. January 2009 (has links)
No / The use of Fourier-transform Raman spectroscopy for characterising lignocellulosics has increased significantly over the last twenty years. Here, an FT-Raman spectroscopic study of changes in the chemistry of waterlogged archaeological wood of Pinus sp. and Quercus sp. from a prehistoric assemblage recovered from northern Greece is presented. FT-Raman spectral features of biodeteriorated wood were associated with the depletion of lignin and/or carbohydrate polymers at various stages of deterioration. Spectra from the archaeological wood are presented alongside spectra of sound wood of the same taxa. A comparison of the relative changes in intensities of spectral bands associated with lignin and carbohydrates resulting from decay clearly indicated extensive deterioration of both the softwood and hardwood samples and the carbohydrates appear to be more deteriorated than the lignin. The biodeterioration of the archaeological timbers followed a pattern of initial preferential loss of carbohydrates causing significant loss of cellulose and hemicellulose, followed by the degradation of lignin.

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