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Heiskari, H. (Hannu). "Development of comminution test method for small drill core sample." Master's thesis, University of Oulu, 2017. http://urn.fi/URN:NBN:fi:oulu-201710112973.
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Grinding circuits are an essential part of a mineral processing plant. Grinding is very energy intensive, and can have major effects on the following separation stages of mineral processing. This sets high requirements for the design and operation of grinding circuits. Early on in the resource evaluation, ore samples used in metallurgical testing tend to be composited samples from drill cores. These composited samples can have broad mineralogical variations in them. Geometallurgy aims to create a predictive model to improve plant operation and design, based on the inherent variability of ore blocks in an ore deposit. Thus to apply geometallurgy, mineralogical information and data about the variability in ore blocks is essential. This creates a need for variability testing, where test methods are fast, inexpensive and require low volumes of sample. In this thesis the common Bond ball mill grindability test is conducted on three different sample materials. The samples show good variability in terms of mineralogy and grindability. Along with the Bond test, the Mergan ball mill grindability test is also conducted on the same sample materials. The Mergan test is faster than the Bond test, and uses less sample material than the Bond test. The aim of the testwork is to analyze the differences between the two test methods, and see if there is a correlation between them. This correlation can then be used to create a new grindability test method, where the test is done with the Outotec Mergan mill, but the test results can be scaled to estimate Bond work index for the sample. Results show that there is indeed a correlation between the two grindability test methods. Using a linear model, an experimental model is presented, where the Mergan mill can be used to approximate the Bond work index for an ore with good correlation. To validate and improve the experimental model presented, more testing should be conducted in the future<br>Jauhatuspiirit ovat tärkeä osa rikastamoa. Jauhatus vaatii erittäin paljon energiaa, ja sillä voi olla merkittäviä vaikutuksia rikastuksen seuraaviin osaprosesseihin. Tämä asettaa korkeat vaatimukset jauhatuspiirien suunnittelulle ja käytölle. Malmiesiintymän tutkimuksen varhaisissa vaiheissa metallurgiseen tutkimukseen saatavat näytteet ovat yleensä komposiittinäytteitä kairasydämistä, joissa voi olla suuria mineralogisia eroja. Geometallurgian tarkoituksena on luoda ennustava malli, joka perustuu malmiesiintymässä olevien eri malmioiden eroavaisuuksiin. Tätä mallia voidaan käyttää kaivoksien suunnittelun ja toiminnan optimoimiseen. Geometallurgian hyödyntämiseen tieto malmioiden eroavaisuuksista ja mineralogiasta on siis välttämätöntä. Tämä on saanut aikaan tarpeen testimenetelmille, joilla tätä vaihtelevuutta voidaan testata, ja näiden testimenetelmien tulee olla nopeita, halpoja, ja testien käyttämien näytemäärien täytyy olla pieniä. Tämän työn kokeellisessa osuudessa yleistä Bondin kuulamyllyjauhautuvuustestiä käytetään kolmen eri malminäytteen jauhautuvuuden testaamiseen. Työssä käytettävät malminäytteet eroavat toisistaan paljon niin mineralogian kuin jauhautuvuudenkin puolesta. Samojen näytteiden jauhautuvuutta testataan myös Mergan kuulamyllyjauhautuvuustestillä. Mergan menetelmän etuja ovat Bondin testiin verrattuna se että Mergan on nopeampi tehdä, ja sen näytevaatimus on Bondin testiä pienempi. Koetoiminnan tarkoituksena on verrata näiden kahden jauhautuvuustestien tuloksia ja eroavaisuuksia, ja analysoida löytyykö näiden testimenetelmien väliltä korrelaatiota. Tätä korrelaatiota voidaan sitten käyttää uuden jauhautuvuustestin kehittämiseen, jossa näytteen jauhautuvuuden testaamiseen käytetään Outotecin Merganmyllyä, ja saatu tulos skaalataan Bondin ”työindeksiin”. Koetulosteen perusteella jauhautuvuustestien väliltä löytyi korrelaatio. Tätä korrelaatiota käytetään kokeellisen lineaarisen mallin luomiseen, jossa malmin jauhautuvuutta voidaan testata Merganmyllyllä ja arvioida siitä Bondin ”työindeksi” hyvällä korrelaatiolla. Kokeellisen mallin toimivuuden vahvistamiseen ja parantamiseen tarvitaan kuitenkin vielä lisää testejä tulevaisuudessa
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Pillière, Henry, Thomas Lefevre, Dominique Harang, et al. "3D Imaging on heterogeneous surfaces on laterite drill core materials." TU Bergakademie Freiberg, 2017. https://tubaf.qucosa.de/id/qucosa%3A23183.
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The SOLSA project aims to construct an analytical expert system for on-line-on-mine-real-time mineralogical and geochemical analyses on sonic drilled cores. A profilometer is indispensable to obtain reliable and quantitative data from RGB and hyperspectral cameras, and to get 3D definition of close-to-surface objects such as rheology (grain shape, grain size, fractures and vein systems), material hardness and porosities. Optical properties of minerals can be analyzed by focusing on the reflectance.
Preliminary analyses were performed with the commercial scan control profilometer MI-CRO-EPSILON equipped with a blue 405 nm laser on a conveyor belt (depth resolution: 10 μm; surface resolution: 30x30 μm2 (maximum resolution; 1m drill core/4 min). Drill core parts and rocks with 4 different surface roughness states: (1) sonic drilled, (2) diamond saw-cut, polished at (3) 6 mm and (4) 0.25 μm were measured (see also abstract Duée et al. this volume). The ΜICRO- EPSILON scanning does not detect such small differences of surface roughness states. Profilometer data can also be used to access rough mineralogical identification of some mineral groups like Fe-Mg silicates, quartz and feldspars). Drill core parts from a siliceous mineralized breccia and laterite with high and deep porosity and fractures were analyzed. The determination of holes’ convexity and fractures) is limited by the surface/depth ratio. Depending on end-user’s needs, parameters such as fracture densities and mineral content should be combined, and depth and surface resolutions should be optimized, to speed up “on-line-on-mine-real- time” mineral and chemical analyses in order to reach the target of about 80 m/day of drilled core.
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Pillière, Henry, Thomas Lefevre, Dominique Harang, et al. "3D Imaging on heterogeneous surfaces on laterite drill core materials." Technische Universitaet Bergakademie Freiberg Universitaetsbibliothek "Georgius Agricola", 2018. http://nbn-resolving.de/urn:nbn:de:bsz:105-qucosa-231235.
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The SOLSA project aims to construct an analytical expert system for on-line-on-mine-real-time mineralogical and geochemical analyses on sonic drilled cores. A profilometer is indispensable to obtain reliable and quantitative data from RGB and hyperspectral cameras, and to get 3D definition of close-to-surface objects such as rheology (grain shape, grain size, fractures and vein systems), material hardness and porosities. Optical properties of minerals can be analyzed by focusing on the reflectance.
Preliminary analyses were performed with the commercial scan control profilometer MI-CRO-EPSILON equipped with a blue 405 nm laser on a conveyor belt (depth resolution: 10 μm; surface resolution: 30x30 μm2 (maximum resolution; 1m drill core/4 min). Drill core parts and rocks with 4 different surface roughness states: (1) sonic drilled, (2) diamond saw-cut, polished at (3) 6 mm and (4) 0.25 μm were measured (see also abstract Duée et al. this volume). The ΜICRO- EPSILON scanning does not detect such small differences of surface roughness states. Profilometer data can also be used to access rough mineralogical identification of some mineral groups like Fe-Mg silicates, quartz and feldspars). Drill core parts from a siliceous mineralized breccia and laterite with high and deep porosity and fractures were analyzed. The determination of holes’ convexity and fractures) is limited by the surface/depth ratio. Depending on end-user’s needs, parameters such as fracture densities and mineral content should be combined, and depth and surface resolutions should be optimized, to speed up “on-line-on-mine-real- time” mineral and chemical analyses in order to reach the target of about 80 m/day of drilled core.
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Hardy, Andrew John 1965. "Fragment size distribution of in situ rock masses from drill core." Thesis, The University of Arizona, 1993. http://hdl.handle.net/10150/278324.
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The success of rock fragmentation by blasting and subsurface fluid flow depends on many variables, including in-situ fragmentation. This study presents select data from a review of over 13000 feet of core samples drilled at seven different mine properties in the United States and Chile. Two-dimensional computer simulations of fractures can be used to quantify the volume of rock required to calculate a stable estimate of mean fragment size. Spatial periodicity of fragment size measurements is indicated through vertical variograms and is used as the basis for a statistical analysis for the zoning of rock masses. A more reliable quantitative method to characterize the size distribution of in-situ rock using digital image processing of drill core photographs is also included. Furthermore, a complete experimental analysis is provided for the comparison of currently used correction methods used to develop the full volumetric fragment size distribution curve.
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Gao, Shanshan, and 高珊珊. "Coring process monitoring for strength of grout, concrete and rock in laboratory testing." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B45530361.
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Guttenkunst, Emy. "Study of the wear mechanisms for drill bits used in core drilling." Thesis, Uppsala universitet, Tillämpad materialvetenskap, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-355399.
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The thesis work was made in cooperation with the I-EDDA project who evaluates the drill equipment used in core drilling. The aim of this work was to determine how and why the drill bits are worn. The work consisted of two parts; investigate drill bits used in field tests and develop a lab scale method to be able to change one drill parameter at a time and see how it affects the wear. During the field tests the rotational speed and the pressure on the drill bits were changed between the three boreholes drilled. In the lab test one parameter at a time was changed; the rotational speed, the water flow and the load. The lab test was developed to attempt to replicate the core drilling and was performed by pressing a piece of a drill bit against a rotating stone cylinder. The drill bits from the field tests and lab test were analysed with the same methods on both macro- and microscale for easier comparison. The results indicate that the lab scale test can be used to evaluate the wear of drill bits. The analyses show rock present on the matrix of all the drill bits, in various amounts. The load has the largest impact on the wear of the drill bits and cause a change in mechanism. A high pressure leads to a higher amount of damaged diamonds and three body abrasive wear on the matrix. Lower pressure leads to polished diamonds and erosive wear on the matrix.
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Larsson, Corominas Miquel Sven. "Unsupervised Feature Extraction from CT Images for Clustering of Geological Drill Core Samples." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-265543.
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Computed tomography (CT) scanned drill cores provide a high resolution view of the internal structure and composition of the rock, which is interesting for many analysis purposes. Although, this data is very high dimensional and difficult to analyze in an automatic way. In this work, a study of how to reduce the dimensionality of these samples is done, with the objective of being able to find low dimensional representations, which then can be clustered into distinct geologically meaningful groups. Due to the complex nature of the data, a high degree of preprocessing is required - involving thresholding, normalization, cropping, etc. First, in order to obtain a baseline for the clusters, a clustering of the chemical compositions of the samples is done, which results in overly simplistic clusters - separating ore from the rest, due to the continuous nature of the data. For the CT data, two approaches are tested - IPCA and convolutional autoencoders, which are able to successfully reduce the dimensions of the scanned samples. For the latter, different bottleneck dimensions are tested in order to evaluate its effect in the resulting reconstruction errors. Nevertheless, when attempting to cluster the low dimensional embeddings, the algorithms only manage to separate the ore from the rest of the samples, as in the chemical clustering, which is too simplistic. An alternative approach is tested in order to obtain an insight of the holes - using UMAP 3D projections as RGB color coordinates, which provide colored maps of the holes that make more geological sense and provide more information than the previous approach. To finalize, an experiment is performed by creating eight distinct classes of synthetic volumetric data with different textures and grain sizes, which resemble rock material, in order to validate the approach of clustering the convolutional autoencoder latent representations. For a sufficient number of channels, all synthetic classes are able to be clearly separated. Interestingly, latent representations of classes with bad reconstructions are still able to be clustered satisfactorily.<br>Datortomografi (DT) av borrkärnor ger en högupplöst bild av den interna strukturen och sammansättningen av berget, vilket är intressant ur flera analyssynpunkter. Den här typen av data är dock av mycket hög dimensionalitet, och är därför svår att analysera automatiskt. I detta arbete görs en studie av hur dimensionaliteten kan reduceras, med syfte att hitta representationer av låg dimensionalitet, vilka sedan kan samlas i geologiskt meningsfulla, distinkta grupper. På grund av datats komplexa natur behövs en hög grad av förbearbetning så som tröskelvärden, normalisering, klippning, etc. I utgångspunkten, för att erhålla en baslinje för klustern, gjordes en gruppering av den kemiska kompositionen av proverna, vilket resulterade i alltför simplistiska klusters med endast en separation av malmen från resten av bergartsprovet, på grund av den kontinuerliga karakteristiken av datat. För DT datat prövades olika angreppssätt - IPCA och faltningsankodare, vilka successivt kan reducera dimensionen hos datat. För det senare fallet provas olika flaskhalsdimensioner för att utvärdera deras effekt på de resulterande rekonstruktionsfelen. Vid försök att gruppera den lågdimensionella representationen däremot, så visar sig bergets egen kontinuerliga natur vara ett hinder, eftersom algoritmen bara lyckas skilja malm från resten, vilket är alltför förenklat. Ett alternativt angreppssätt provas för att få en insikt om borrhålen - genom UMAP 3D-projektioner som RGB-färgkoordinater, vilket resulterade i en geologiskt relevant färgkartläggning av borrhålet och gav en bättre information än den tidigare metoden. Avslutninsvis utfördes ett experiment genom att skapa åtta distinkta klasser av syntetiska volumetriska data med olika texturer och kornstorlek, liknande berggrundsmaterial, för att utvärdera riktigheten hos grupperingen från den faltande autoankodarens latenta representation. Med tillräckligt antal kanaler är alla syntetiska klasser tydligt separerbara. Intressant nog: latent representation av klasser med dålig rekonstruktion är fortfarande möjliga att gruppera tillfredsställande.
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Tiu, Glacialle. "Classification of Drill Core Textures for Process Simulation in Geometallurgy : Aitik Mine, Sweden." Thesis, Luleå tekniska universitet, Mineralteknik och metallurgi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-65207.
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This thesis study employs textural classification techniques applied to four different data groups: (1) visible light photography, (2) high-resolution drill core line scan imaging (3) scanning electron microscopy backscattered electron (SEM-BSE) images, and (4) 3D data from X-ray microtomography (μXCT). Eleven textural classes from Aitik ores were identified and characterized. The distinguishing characteristics of each class were determined such as modal mineralogy, sulphide occurrence and Bond work indices (BWI). The textural classes served as a basis for machine learning classification using Random Forest classifier and different feature extraction schemes. Trainable Weka Segmentation was utilized to produce mineral maps for the different image datasets. Quantified textural information for each mineral phase such as modal mineralogy, mineral association index and grain size was extracted from each mineral map. Efficient line local binary patterns provide the best discriminating features for textural classification of mineral texture images in terms of classification accuracy. Gray Level Co-occurrence Matrix (GLCM) statistics from discrete approximation of Meyer wavelets decomposition with basic image statistical features[PK1] (e.g. mean, standard deviation, entropy and histogram derived values) give the best classification result in terms of accuracy and feature extraction time. Differences in the extracted modal mineralogy were observed between the drill core photographs and SEM images which can be attributed to different sample size[PK2] . Comparison of SEM images and 2D μXCT image slice shows minimal difference giving confidence to the segmentation process. However, chalcopyrite is highly underestimated in 2D μXCT image slice, with the volume percentage amounting to only half of the calculated value for the whole 3D sample. This is accounted as stereological error. Textural classification and mineral map production from basic drill core photographs has a huge potential to be used as an inexpensive ore characterization tool. However, it should be noted that this technique requires experienced operators to generate an accurate training data especially for mineral identification and thus, detailed mineralogical studies beforehand is required.<br>Primary Resource Efficiency by Enhanced Prediction (PREP)<br>Center for Advanced Mining and Metallurgy (CAMM)
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Hull, Angela Lynn. "Geochronology and thermochronology of Precambrian basement drill core samples in Nebraska and southeastern South Dakota." Kent State University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=kent1385078311.
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Manthri, Sandeep. "EXPERIMENTAL INVESTIGATION OF PCD COMPACT CORE DRILL PERFORMANCE ON BASALT SIMULATING SUSTAINABLE DRY DRILLING ON MARS." UKnowledge, 2007. http://uknowledge.uky.edu/gradschool_theses/495.
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Missions to Mars aim to characterize rock and subsurface soil samples and possibly bring some back to Earth for more thorough and sophisticated examination. The Martian surface is covered with basalt which has high compressive strength (andamp;gt;130 MPa), and is more difficult to drill than the much softer sedimentary formations that are presently being drilled using diamond core drills. The main objective of this thesis work is to provide the requisite groundwork towards the development of improved and sustainable drills for subsurface drilling applications on Mars, when their goals are obtaining samples. Since progressive drill-wear is substantial in sustained drilling, the experiments were designed and conducted to study the tool-wear mechanisms and understand the associated effects on drilling performance in subsurface drilling of basalt. Core drilling experiments are conducted with different drill geometries and cutting conditions in a Martian simulant, basaltic rock; monitoring thrust force, torque and measuring tool-wear for a series of successive depth-increments. Based on the experimental results an optimization model has been developed for maximizing drilling depth with minimum tool-wear. This preliminary work will help the development of smart and sustainable drills for dry drilling applications for future NASA missions to Mars.
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Bjork, Andreas. "Characterizing magnetic susceptibility and remanent magnetization of magnetite and hematite rich drill-core samples at Blötberget." Thesis, Uppsala universitet, Geofysik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-347975.
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Laboratory magnetic measurements are used to develop a methodology to characterize the Kiruna-type Rare Earth Elements (REE) bearing apatite iron-oxide deposits at Blötberget in central Sweden. This high-grade ore deposit is known to have sharp boundaries between lens shaped main ore bodies of magnetite-rich ore, and a complex hematite-rich ore associated with pegmatites and skarn formation. The thesis covers laboratory magnetic measurements of 37 samples originating from eight drill cores and reference samples from previously mined area. It focuses on on-covering how the samples relate in terms of magnetic susceptibility, further its dependency on temperature, frequency, field and the orientation. The results are correlated with petrographic analysis previously performed on accompanying thin sections. The measurements show that magnetite with strong susceptibility contribution overshadow the hematite contribution in the samples. Transition changes in susceptibility are noticeable when crossing the Verwey temperature; -153°C, Curie temperature; 580°C and Néel temperature; 680°C. The Morin temperature appears at -60°C, or is missing. Linear relationships are identified between the magnitude difference in susceptibilities across transitions at high temperature and wt% magnetite and hematite have been identified. The Blötberget skarn and hematite-rich ore samples have a higher degree of susceptibility anisotropy than the other ore-types. Blötberget samples are dominated by multidomain characteristics in remanence, saturation and coercivity. High temperature measurements have shown that the magnetite is close to pure. The low temperature measurements suggest hematite is impure or bears a petrological footprint. The study also shows that rich iron ore samples sometimes can be at risk of being overlooked with standard methods of measuring susceptibility<br>Laboratorietekniska metoder kan användas som ett komplement till malmgeologi och geofysisk prospektering. I denna metodstudie karaktäriseras apatitjärnmalm från Blötberget, nära Grängesberg. En fyndighet bestående av linsformade malmkroppar rika på magnetit och ofta avskilda men komplexa hematitrika stråk. Studien är gjord 37 prover från totalt 8 borrkärnor, och lokaler som tillhörde produktion från gruvverksamhet under 1900-talet. Mätmetoderna fokuserar på att kartlägga malmens magnetiska egenskaper, och hur temperatur, frekvens, fältstyrka samt riktning påverkar dessa. Resultaten jämfördes med tidigare petrografisk studie av tillhörande tunnslip Resultaten visar att magnetit står för merparten av susceptibiliteten i proverna, men att även hematit kan urskiljas och kvantifieras. Temperaturberoende har påvisats vid övergångar för Verwey-temperatur; -153°C, Curie-temperatur; 580 °C, och Néeltemperatur; 680 °C. Den förväntade Morin-temperaturen vid -14°C, påträffades vid -60 °C eller saknas helt för flera av de hematitrika proverna. Magnetiskt anisotropa prover återfinns bland prover som identifierats som skarn eller hematitrika. Magnetisk granulometri visar karaktär av multidomäntyp med låg magnetisk coercivitet och hög satureringsförmåga. Högtemperaturmätningar av susceptibilitet visar på ren magnetit för prover från Blötberget. Samtidigt visar lågtemperaturemätningar att hematit sannolikt har inblandning av titanium eller bär på ett mer komplext förflutet. Studien visar också att det finns en risk i att enbart förlita sig på bulksusceptibilitet för prover rika på malm.
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Dahl, Gustav. "Mineralisering, omvandling och ursprungliga bergarter av borr-kärnor från Renströmområdet,Skelleftefältet." Thesis, Uppsala universitet, Mineralogi, petrologi och tektonik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-352911.
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Brytning av ekonomiskt värdefulla resurser sker över hela världen och effektiviseras kontinuerligt. Ökad brytning av mineral innebär att lättåtkomliga malmkroppar förbrukas. När de lättåtkomliga kropparna av dessa mineraler använts upp krävs det prospekteringsmetoder för att leta djupare in i jordskorpan. En sådan metod är borrkärnekartering.Syftet var att detaljerat beskriva borrkärnans petrofysiska egenskaper samt lokalisera potentiell ekonomiskt område med hjälp av borrkärnekartering. Två borrkärnor karterades och undersöktes med hjälp av en handhållen XRF. Borrkärnekarterings potential som prospekteringsmetod utvärderades.Malmkropp innehållandes stor del Zn samt Pb, Cu och Fe identifierades i båda borrkärnorna. pXRF och kartering lokaliserade malmkropp i liknande omfång och gradering. Ursprungsbergarter och dess sammansättning identifierades.Prospekteringsmetoder som borrkärnekartering fungerar mycket bra i de fall övergripande information om borrkärnan behövs omgående. Borrkärnekartering är således en effektiv metod som kan användes vid borrplatsen för att kontinuerligt ge information om borrkärnan och således avgöra om borrning ska fortsätta eller avslutas. Prospekteringsmetoden fungerar bäst i kombination med andra metoder, geokemiska eller geofysiska.<br>Mining of economically important resources is a process happening all over the world and have been increasing in effectiveness during the last century. Increased mining of the resources means that the easily accessed bodies of these minerals is exhausted. Prospecting methods to find new bodies in the ground is then needed. One of these methods is core logging.The goal of the project was to locate potential valuable mineralization. Two different cores were logged and evaluated with a hand held XRF during the project. The effectiveness of core logging as an exploration method was evaluated.Ore body containing large amounts of Zn as well as Pb, Cu and Fe were identified in both drill cores. pXRF and logging gave the same size and grades of the ore body. Protoliths and its composition were identified.Exploration methods like core logging is useful when summary information of the drill core is necessary and the information needs to be given fast. The method is therefore effective in the field at the drill stations to give continuously information about the drill cores being drilled. The method is most effective when combined with other methods like geochemical or geophysical methods.
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Chong, Ting-Fung. "Mineralogy and petrology of a drill core section from Borg, SW Norrköping – fracture fillings and tentative mineral reactions." Thesis, Stockholms universitet, Institutionen för geologiska vetenskaper, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-173221.
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During drilling at Borg, ca. 5 km southwest of central Norrköping, an unidentified fine-grained grey rock was encountered in contact with dark red granitic gneiss at 35m depth. The fine-grained grey rock occurs above the red granitic gneiss. Our understanding prior to testing is that the rock may have been formed by fluid alteration of a mafic rock, as neither metamorphic nor sedimentary textures were observed. Understanding this rock and the formation processes related to it, is of interest for the general understanding of the region and of geotechnical importance since fracture fillings may affect the stability of the rock during and after construction projects. This study uses the methods petrography, XRD and XRF to define the fine-grained mafic rock, black vein in the fine-grained mafic rock, the contact zone and the granitic gneiss. Results show that the fine-grained grey rock has a composition of muscovite (36.1%), quartz (24.6%), albite (20.8%), sericite (10.8) and montmorillonite (0.5%). The contact is mainly made of quartz veins and calcite veins. The protolith of the fine-grained mafic rock is suggested to be iron-rich. Further testing on additional unaltered mafic rock samples from the area would provide a more accurate picture of the protolith evolution.
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Banks, Graham John. "Accretion of the lower oceanic crust in the Troodos ophiolite : textural and geochemical constraints from drill core Cy-4, Cyprus." Thesis, Cardiff University, 2004. http://orca.cf.ac.uk/55376/.
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Many processes involved in the accretion of lower oceanic crust remain enigmatic. To investigate some of these processes, the principal focus of this study is drill core 'CY-4', an unbroken 2.2km long section through sheeted dykes and mafic and ultramafic cumulates of the Troodos ophiolite lower crust, Cyprus. The generally accepted hypothesis states CY-4 intersected an axial magma chamber that was intruded by an off-axis pluton, based on a 'stepped' increase in clinopyroxene titanium content at 1331 m depth. This comprehensive structural, textual and trace element examination throughout CY-4 indicates a single, open system, plutonic sequence. It is comprised of high-level, varitextured gabbros, underlain by foliated gabbronorites and low-level, banded, gabbronorites and ultra mafic cumulates. Steeply inclined planar and linear fabrics were generated by upward migration of magma. Flow was predominantly channelised through the upper cumulates and diffuse through the lower cumulates, with corresponding differences in preserved structures and textures. Channelised flow and magma remobilisation in the rapidly cooled and poorly equilibrated upper cumulates is responsible for the decametre-scale textural and chemical variations. Syn-tectonic porous flow through the slower-cooled banded cumulates led to grain-scale textural and chemical interactions. Any initial mineral co-variations were erased during supra-solidus equilibration and efficient expulsion of incompatible element-rich melts. Any early-formed layering was transposed. A new model of CY-4 accretion is proposed in which a broad range of depleted and boninitic magma compositions were efficiently homogenised in the lower crust to yield the narrower ranges of extruded compositions. Correlations with Troodos Lower an Upper Pillow Lava series may indicate sources within the foliated gabbronorites, and the deeper ultramafic region respectively. The structural resemblance of the CY-4 cumulate series to fast-spreading lower crust can be reconciled with the slow spreading rate calculated for Troodos if CY-4 intersected a ridge axial node of magma upwelling
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Chomyn, Beverley Anne Carleton University Dissertation Geology. "The relation between magnetic properties, density, opaque mineralogy and chemistry in drill core from the Lac Du Bonnet batholith, Manitoba." Ottawa, 1987.
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Watton, Timothy James. "A multidisciplinary assessment of hyaloclastite deposits in petroleum systems using field studies, drill core, borehole image and wire-line log datasets." Thesis, Durham University, 2013. http://etheses.dur.ac.uk/7762/.
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This thesis aims to document hyaloclastite deposits in different depositional environments from field outcrops in Iceland to characterise lithofacies heterogeneity enabling comparison to subsurface datasets. Field hyaloclastite datasets from Stóri-Núpur (subaerial-marine transition) and Hjörleifshöfði (an emergent Surtseyan volcano) are used to support the interpretation of hyaloclastite and associated volcanic deposits in core, borehole image logs and wire-line log datasets from Hawaii (Hawaiian Scientific Drilling Project II – HSDP II borehole) and the Faroe-Shetland Basin (LOPRA1/1A well and the Rosebank field). This study provides additional constraints on lava delta formation in predominantly basaltic systems where hyaloclastite depositional profiles reflect localised extrusion pathways and syn-sediment reworking which control 3D lithofacies architecture. Furthermore this thesis documents the evolution of Hjörleifshöfði using field mapping and major/trace element geochemistry. Hjörleifshöfði can split into five phases of deposition charting the submarine to emergent building of the volcano, unique as it also records a phase of silicic volcanism (Sólheimar Ignimbrite) which dates late stage volcanism to no earlier than 12,383 C14 years BP. Petrophysical and petrographic observations suggest hyaloclastite deposits are unique in terms of their velocity/density and P and S wave relationships due to palagonite formation, basalt clast support, phenocryst and zeolite component amongst others which impacts on depth conversion and the calculation of reflection coefficients. Wire-line log response gamma-ray (GR), resistivity (RES), P-wave sonic velocity (Vp) is also closely linked to the dominant interstitial secondary minerals and phenocryst components of sideromelane glass. Borehole image log analysis of mixed volcanic and volcaniclastic rocks allows the accurate characterisation of distinct internal lava flow features, contact relationships and joint networks enabling better characterisation of volcanic sequences in the subsurface via careful comparison with field examples. Field, core and wire-line log data is combined to form a multidisciplinary assessment of hyaloclastite deposits in the subsurface suggesting that the complexity and scaling issues in hyaloclastite rocks is generally overlooked which may impact on future petroleum exploration in volcanic basins.
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Hill, Herbert Hill. "Assessing the Influence of mineralogy and texture on the ore breakage characteristics of drill core and crushed ore using the JKRBT." Master's thesis, Faculty of Engineering and the Built Environment, 2021. http://hdl.handle.net/11427/32679.
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Textural variability is a key component in addressing process challenges resulting from variability in the ore being mined. Textural variability arises from differences in the types of mineral grains present, their relative abundance and the type of interactions they have with one another. Increased textural variability is the largest contributor to mineral processing challenges in terms of mill throughput and flotation concentrate grades. Processing of ores with high textural variability often results in reduced throughput and the recovery of lower grade product, if low-grade material is not eliminated prior to arriving at the concentrator. Geometallurgy provides a powerful tool to manage ore variability better by using geological and metallurgical information during plant design and operation. The geometallurgical approach contributes towards minimising and controlling operational and technical risk of ore variability. Ore breakage characterisation is a pivotal part of geometallurgy which aims to quantify the relationship between the energy supplied for breakage and the size of the resultant progeny. The Julius Kruttschnitt Rotary Breakage Tester® (JKRBT) is an ore breakage characterisation device designed as a geometallurgical tool which can use both crushed ore and drill core samples. Drill core is especially important as it the material used for geometallurgical testing during exploration and resource definition. The JKRBT is more accurate and the test work is less time consuming than its predecessors. However, sample availability is a major concern when performing metallurgical testing as numerous tests need to be performed to get a complete view of the metallurgical response of the given ore type. This means that very little of the sample is available for ore breakage characterisation. The aim of this work is to understand the relationship between mineral texture and the ore breakage characteristics of several samples for both drill core and crushed ore which are the two sample types used at exploration and operational levels. The work is aimed at addressing the problem of sample availability in geometallurgical testing by developing an ore breakage characterisation test protocol that uses minimal sample to extract relative hardness indices. To assess the influence of mineral texture on the ore breakage characteristics, five different ore types were used. The ore was prepared by coring different size drill core and crushing using a jaw crusher. The samples were subjected to controlled single impact breakage tests using the JKRBT. A standard test consisted of 3 energy levels (low, medium and high) tested on 3-4 particle size fractions (small, medium, large and very large). The least particle protocol was developed using an ore which was considered to be fine-grained and homogenous. In developing the protocol, all the steps of the standard procedure were followed except the number of particles per test was progressively reduced from 30 particles to a threshold of 5 particles. From ore breakage characterization tests performed, it was observed that ore S was the most resistant to breakage while ore P was the least resistant to breakage. Ore A was found to be more competent than ore B and ore C but less competent that ore P. The differences in the ore breakage characteristics were attributed to the grain size distribution of the dominant constituent minerals for each sample. The findings were attributed to an increase in the surface area available for contact due to the decrease in grain size which results in less stress per unit area and thus more resistance to breakage. The hardness of an ore can be considered to be a function of the mineral hardness and its relative abundance. Using the relative mineral abundance and Mohs hardness scale, it was concluded that the more abundant the harder minerals in an ore, the more resistant to breakage the ore is. Drill core particles consistently produced a coarser progeny than crushed particles at the same conditions. The observed trend was attributed to differences in the particle shape between the crushed particles (angular) and drill core particles (cylindrical). Angular particles have a larger surface area exposed for energy absorption and therefore break more easily than drill cores. Chapter 5 showed that the proposed abridged ore breakage characterisation test that uses the minimal number of particles to extract ore breakage indices can be applied for both homogenous and heterogenous ore types. The results also show that the proposed least particles protocol can be used for ore breakage characterisation tests using both crushed ore and drill core particles. The number of particles can be reduced to as little as 10 particles per test while still obtaining the same ore breakage indices as those obtained from the standard procedure. The abridged protocol will be especially useful in situations where the amount of ore available for metallurgical testing is limited.
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Alfvén, Linda. "Structural and Engineering Geological Investigation of Fracture Zones and Their Effect on Tunnel Construction." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-272495.
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This thesis project was conducted in connection with the project, Stockholm’s future sewer pipeline, which is a planned sewer pipe that will run through a tunnel from western to southern Stockholm. This tunnel will pass under Lake Mälaren between Eolshäll and Smedslätten, where there are two faults indicated on the geological map, that could affect the tunnelling and create risks during the construction. Geophysical- and water-loss measurements along with core drilling have been carried out in the area. The objectives of this thesis are to create a structural and engineering geological understanding of the passage beneath Lake Mälaren based on drill core mapping, field work, data from previous investi-gations and 2D-models of the tunnel excavation both within and outside the indicated fault zone. The core mapping supports the existence of one fault zone, which is indicated on the geological map supported by water-losses at several places along the drill core as well as core losses. Field work indi-cated the existence of a conjugate fracture sets.The 2D-models present plastic behaviour of the rock in the fault zone as the worst case scenario during excavation with the highest deformation displacement. The excavation procedure and the tunnel form also play a significant role. Since this thesis highlights some significant risks and problems that can occur during tunnelling, its findings may be useful during the tunnel construction.<br>Denna uppsats är skriven med koppling till projektet, Stockholms framtida avloppsledning, vilket inkluderar en ny tunnel för transport av avloppsvatten från västra till södra Stockholm. Tunneln kommer att passera under Mälaren mellan Smedslätten och Eolshäll, där det är två förkastningar indikerade på geologiska kartor som kan orsaka stora risker för byggnationen av tunneln. Geofysiska mätningar, kärnborrning och vattenförlustmätning har tidigare utförts i området. Målen för denna uppsats är att skapa en geologisk- och bergmekanisk förståelse för tunnelpassagen under Mälaren utifrån kärnkartering, fältarbete, data från tidigare undersökningar och 2D-modeller av tunneluttag i den indikerade zonen och utanför. Kärnkarteringen stödjer existensen av en förkastningszon som finns på den geologiska kartan. Flertalet vattenförluster är indikerade längs med hela kärnan tillsammans med en del förekomster av kärnförluster. Fältarbetet indikerar på förekomst av ett konjugerande sprickset. 2D-modeller över tunneln visade att olika egenskaper på berget samt hur uttaget av tunneln sker har betydelse för deformationernas storlek. Den här uppsatsen belyser några viktiga problem och risker som kan uppstå under tunnelbyggnationen, dessa upptäckter kan därför vara användbara och värdefulla under hela byggnationen.
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Ball, Nathaniel H. Atchley Stacy C. "Depositional and diagenetic controls on reservoir quality and their petrophysical predictors within the Upper Cretaceous (Cenomanian) Doe Creek Member of the Kaskapau Formation at Valhalla Field, Northwest Alberta." Waco, Tex. : Baylor University, 2009. http://hdl.handle.net/2104/5296.
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Jardine, Mitchel. "Three dimensional quantitative textural analysis of nickel sulphide ore using X-ray computed tomography and grey level co-occurrence matrices on drill core." Master's thesis, University of Cape Town, 2016. http://hdl.handle.net/11427/20489.
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Alongside the global trend to mine and process lower grade and more mineralogically complex ores, there has been an increased awareness of the prevalence of ore heterogeneity. Ore texture - the interrelationship of minerals comprising a rock, has been identified as one of the primary geometallurgical indicators of ore variability. It is well known that a relationship exists between ore texture and the resultant metallurgical performance (ore hardness, throughput, liberation, grade, recovery). Consequently, there exists a need to rapidly, routinely, cost effectively, and reliably quantify ore texture and its variability prior to mining. This information can thereafter be incorporated into the geometallurgical block model and used for decision making informing mine planning, plant operation and optimisation, forecasting, and mine closure. The ability to rapidly, routinely, cost effectively and reliably quantify ore texture remains an ongoing challenge. In this study, the use of 3D X-ray computed tomography (XCT) is proposed as an innovative solution to non-destructively image the internal structure of drill core. Thereafter, an established, discipline independent two dimensional (2D) image analysis technique known as grey level co-occurrence matrices (GLCM) is specially adapted into three dimensions (3D) to quantify ore texture using XCT grey level volumes of drill core.
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Piribauer, Christoph [Verfasser], Franz Michael [Akademischer Betreuer] Meyer, and Ronald [Akademischer Betreuer] Bakker. "Fluid inclusions in the Outokumpu deep drill core : implications for palaeofluid evolution and the composition of modern deep saline fluids / Christoph Piribauer ; Franz Michael Meyer, Ronald Bakker." Aachen : Universitätsbibliothek der RWTH Aachen, 2015. http://d-nb.info/1126278408/34.
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Olausson, Hanna. "Rörelseriktning på förkastningszoner i Stocksund och Södermalm." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-352311.
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Stockholm stad är inne i en expansiv fas. En växande befolkning ökar inte bara behovet av ett mer ansvarsfullt markanvändande utan också en välfungerande infrastruktur. Med avseende på detta så har det de senaste åren skett och fortsätter ske, en rad större projekt som inkluderar arbete både direkt i och i nära anslutning till berg. Detta ställer höga krav på förståelse för det berg man jobbar i och därför utförs noggranna geologiska undersökningar innan ett projektarbete tar vid. Denna studie fokuserar på två sådana områden där mycket infrastrukturell aktivitet i berg har förekommit de senaste åren. Undersökningsområde nummer 1 är Stocksund och innehåller data som tagits fram i samband med utbyggnaden av elnätet i projekt City link. Område nummer 2 är Slussen på Södermalm med information som erhållits i samband med ombyggnationen av trafikplatsen. Då omfattande förundersökningar och kartläggningar har gjorts för respektive område har redan befintliga data kunnat användas på nytt i detta arbete. Studien har som syfte att undersöka tidigare förkastningar och deras rörelseriktningar i området. För att göra detta har borrkärnor från respektive lokal analyserats för att hitta rörelseindikatorer som kan påvisa hur förkastningen såg ut när den skedde. Slickenside är en typ av rörelseindikator som kan användas för detta ändamål. I varje borrkärna hittades fem stycken ytor som uppvisade slickenside och som därför har undersökts vidare.<br>The city of Stockholm is in a phase of expansion. A growing population does not only increase the need of a more responsible usage of land areal but also the need of a high functioning infrastructure. Due to this development a lot of large-scale projects including work in direct and in close contact to rock have been performed or are currently underway. This demands a great deal of knowledge on the certain rock-types involved in said projects and therefore thorough geological investigation takes places before any project can start. This study will focus on two of these areas where a lot of infrastructural activity in rocks have taken place during recent years. Examination area one is in Stocksund and contains data that was maintained in connection with the expansion of the power grid called project “City link”. Area two is located in Slussen, Södermalm where the information comes from the major reconstruction of the traffic juncture. Since several investigations and surveys have been conducted, old data from earlier projects has proven useful for this study. The study aims to investigate previous faults and their sense of movement in the area. In order to do so, drill cores from each site have been analyzed in order to find sense indicators that can provide information about the fault. Slickenside is a kinematic indicator that can be used for this. Each area had one drill core and in each of them five slickensides were identified and examined further.
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Niegisch, Max, Andreas Kamradt, and Gregor Borg. "The upper zone of the Storkwitz Carbonatite: Geochemical and mineralogical characterization of the REE-mineralisation in the upper zone of the Storkwitz Carbonatite Complex from drill core SES-1/2012." Sächsisches Landesamt für Umwelt, Landwirtschaft und Geologie, 2020. https://slub.qucosa.de/id/qucosa%3A71506.
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Im Umfeld von Delitzsch befinden sich unter der etwa 100 m mächtigen Bedeckung aus tertiären Lockersedimenten mehrere magmatische Körper aus Karbonat. Im Jahr 2012 wurde durch die Deutsche Rohstoff AG bei Storkwitz eine 700 m tiefe Explorationsbohrung auf Seltene Erden Elemente abgeteuft. Im Rahmen eines Forschungsprojektes wurde der Frage nachgegangen, wie und woher die Seltenen Erden in das Gestein hineingelangten. Die Ergebnisse können Hinweise auf möglicherweise bisher unbekannte Anreicherungen von Seltenen Erden in anderen Nebengesteinen als den Karbonatiten geben.
Die Veröffentlichung liegt nur in englischer Sprache vor.<br>The Storkwitz-Carbonatite is a Late Cretaceous intrusive complex, which is well-explored by a relatively large number of exploration bore holes both from the 1970ies, 1980ies and from one more recent bore hole, SES-1/2012. The carbonatite complex hosts a (currently) marginally economic mineralisation of rare earth elements (REE) and niobium, which is technically still difficult to recover. The upper part of the carbonatitic body is located some 100-120 m below the Pre-Cenozoic land surface, which in turn is overlain by approximately 100 m of glacial, fluvio-glacial, and fluviatile sediments. The aim of this study was to characterize the mineralisation in the upper part of the intrusion geochemically
and mineralogically and to try to identify indications of a supergene overprint on the late magmatic to hydrothermal mineralisation. Fresh drill core samples from the exploration bore hole SES-1/2012 have revealed that the mineralisation is associated with a carbonatitic igneous breccia body and also with several alvikite veins. The breccia body is very heterogeneous, displays a variety of matrix colours and also a range of matrix-to-clast ratios.
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Höglund, Madicken, and Marcus Larsson. "Grundförstärkning med pålar i berg : I befintlig konstruktion med begränsat utrymme." Thesis, KTH, Byggteknik och design, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-287735.
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This study has been done in order to examine which type of pile, pile driving- and waterproofing methodsare most suited for an existing building. A building that will undergo an extensive reinforcement of itsfoundation.The study has been made in regard to the following conditions:● Different types of clay soil (Cohesion soil)● Underlying rock structure with heavy incline (8° slope)● Sensitive environment for vibrations and ground displacements● Limited accessibility (Room and maximum weight)● Compressive and tensile forces● Pool (Water environment)To answer the questions of statement a scientific literature study, interview with a foundation expert,calculations in sizing, but also time and cost analysis has been conducted. A site visit to an object ofreference, Nya Krav Himmerfjärdsverket, occurred where a reconstruction of an existing building withextensive work of reinforcement to its’ foundation was in progress.The steel pipe pile with anchor and steel core pile are the best pile types in such conditions as compressiveand tensile forces, clay soil with underlying inclined rock bed, limited accessibility and sensitivesurrounding environment. Which pile type, pile driving- and waterproofing methods that are most suited forsuch conditions is different for each project. The steel core pile is more suitable for higher loads, rockstructures in incline and when verification of load capacity is not needed. At the same time the steel pipepile is more suited when the underlying rock bed is far below ground level, where you would need manypile elements and joints. In addition, the steel pipe pile is suitable for buildings with a complex loaddistribution, where a greater number of piles with lower load capacities is needed in order to satisfy this.The best pile driving method for drilling in sensitive environment is the water equipped down-the-hole(DTH) drill. This drilling method is gentle to surrounding piles in existing building.In order to minimise the risk of water penetration and then expand the life span of the construction, use ofa combination of different waterproofing systems is to prefer when waterproofing pile heads or pilefoundations.
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Hibbert, Fiona Danielle. "Dynamics of the British Ice Sheet and prevailing hydrographic conditions for the last 175,000 years : an investigation of marine sediment core MD04-2822 from the Rockall Trough." Thesis, University of St Andrews, 2011. http://hdl.handle.net/10023/3136.
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This study presents a stratigraphic investigation of the marine sediment core MD04-2822 from the Rockall Trough (56° 50.54' N, 11° 22.96' W; 2344 m water depth). This core is currently the only available high resolution record for the calibration of Late Quaternary sedimentary sequences of the British (Hebridean) margin. It therefore offers an unprecedented archive of changing sedimentological and climatological conditions for the last 175,000 years. The high resolution, multi-proxy records have enabled surface and deep water conditions within the Rockall Trough to be reconstructed. In addition, the fluctuating nature of ice-rafted debris (IRD) inputs to the MD04-2822 site allows a first order attempt of BIS dynamics for the entirety of the last glacial period (i.e. from the demise of the last interglacial to the decay of the Devensian/Weichselian ice sheet) as well as the majority of the penultimate (Saalian/MIS 6) glaciation. Sediment core MD04-2822 is ideally located to capture the dynamics of the British Ice Sheet (BIS) via a continuous record of IRD and fine-grained terrigenous inputs. Fundamental to this is the construction of a robust chronology. This was achieved via: the correlation of the benthic δ¹⁸O record to a global δ¹⁸O stack (SPECMAP); the correlation of the surface proxies (% N. pachyderma (sinistral) and XRF Ca) to the Greenland δ¹⁸O and Antarctic methane ice core records; and radiocarbon dating. This chronology was validated using both radiocarbon dating and tephra horizons. An evaluation of the event stratigraphy approach used in the construction of the MD04-2822 chronology is presented. The marine record provides a valuable archive of past ice sheet dynamics as much terrestrial evidence is removed or obscured by subsequent ice sheet oscillations MD04-2822 provides the first evidence for the expansion of the BIS onto the Hebridean Margin during MIS6 (thereby confirming previous long-range seismic correlations). The continuous sedimentation at MD04-2822 enabled the first insights into the early dynamics of the last BIS. Increases in IRD and fine grained terrigenous material delivered to the MD04-2822 at ca. 72 kyr represent the first significant delivery of material from the BIS across the continental shelf to the core site. The BIS would therefore have attained a marine calving margin by this time. A multi-proxy investigation of provenance was undertaken, however unequivocal provenance determinations remain problematic. The location of the core suggest the proximal BIS as the most likely source of terrigenous inputs. The expanded nature of the MD04-2822 sediments during the penultimate deglacial (Termination II) provides the first details of BIS dynamics for this period: the interplay of large inputs of freshwater from the decay of the Saalian (MIS 6) ice sheets (including the BIS) upon the surface and deep water circulation of the North Atlantic is investigated. In addition, sub-orbital climatic variability is documented at this location throughout the last interglacial (MIS 5e) and appears to be an intrinsic feature of both the N.E. Atlantic surface and deep water circulation of the last 175 kyr.
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Clarin, Viktoria. "En ansats mot förenklad sprickkartering av borrkärna." Thesis, KTH, Jord- och bergmekanik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-231369.
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Detta examensarbete är en ansats mot en förenklad metod för sprickkartering i borrkärna och utvärderar huruvida en förenklad metod är tillämpbar vid projekt som anläggs under aktiv design och tid är en kritisk faktor. Det föreliggande arbetet är en studie baserad på data från Boliden Mineral AB, från undersökningar utförda i syfte att lokalisera en lämplig, lågpermeabel bergvolym för anläggandet av ett slutförvar för miljöfarligt avfall. Vattenflöde i kristallin bergmassa, liksom den i Sverige, förmodas traditionellt påverkas mest av sprickornas karaktär så som sprickdensitet, sprickvidd, råhet, sprickfyllning etc. Vidare påverkar sprickegenskaperna bergmassans hållfasthet, varför karaktärisering av bergmassan utgör en central roll vid byggande i berg. Effektivisering av sprickkartering under aktiv design undersöktes genom att utvärdera hur väl de parametrar som används vid karaktärisering verkar för identifiering av vattenförande strukturer. Vidare utvärderades möjligheten att minska antalet sprickor att kartera och karaktärisera vid den fysiska kärnan. Resultat i denna studie visar inte några tydliga kopplingar mellan mätsektionernas hydrauliska konduktivitet (K) och de individuella karterade parametrarna. Osäkerheterna är dock stora då mätsektionerna för de hydrauliska testerna utgörs av 10 m för uppskattande av K, som dessutom påverkas av storskaliga företeelser (t.ex. grad av sammankoppling) som vidare inte är möjligt att uppskatta från borrhålsdata. Fjärrkartering av borrhålsfilm underestimerar överlag bergkvaliteten för de tre borrhål som analyserades. En förenklad metod med ett representativt urval sprickor för fysisk kartering beskriver fördelningen av parametervärden väl, vid jämförelse mot en fullständig fysisk kartering för två borrkärnor. Lerfyllda sprickor och höga Ja-värden överestimeras dock vid den förenklade karteringen vilket potentiellt kan leda till en mer konservativ förstärkningsåtgärd än nödvändigt. Fler studier behöver dock genomföras för att utvärdera huruvida den förenklade metoden kan reflektera parametervärdenas fördelning för individuella sprickgrupper. Vidare krävs ytterligare undersökningar för utvärdering av hur robusta de presenterade metoderna är vid kartering av borrkärnor med högre sprickighet än de som använts för analys i denna studie.<br>This master thesis is the inception of a simplified method for logging fractures in drill holes and comprises an evaluation on whether a simplified method is applicable for projects where the observational method is used and time is a critical factor. The following work is a study based on data from Boliden Mineral AB, acquired from investigations for locating a suitable, low-permeable rock mass for a repository for hazardous waste. Water flow in crystalline bedrock, such as that found in Sweden, is traditionally thought to be most influenced by fracture characteristics like fracture density, aperture, roughness, fillings etc. Moreover, these same characteristics influence the rock mass strength, which is why the characterization of fractures is fundamental for construction in rock. To improve efficiency of fracture logging in projects maintained under the observational method, an evaluation on how well the quantified fracture characteristics work for identification of large-scale water bearing structures was performed. Furthermore, the possibility of decreasing the number of fractures to log and characterize in the core was investigated. The results show no apparent correlations between hydraulic conductivity (K) in test sections and the individually mapped parameters. However, the uncertainties are significant, mainly because of the large sections in which the hydraulic tests were conducted, but also because of largescale features influencing K (e.g. interconnectivity) which are not possible to estimate from core data. Remote logging of borehole images generally underestimates the quality of the rock mass for the three analyzed boreholes. A simplified method with a representative selection of fractures for physical core logging was found to describe the distribution of parameter values well, when compared to a complete physical core log for two drill cores. Clayfillings and high Ja -values are however overestimated when the simplified method is applied which may lead to a more conservative reinforcement measure than necessary. However, more studies need to be carried out to evaluate whether the simplified method can reflect the distribution of parameter values for individual fracture sets. Moreover, additional studies are required to evaluate the robustness of the suggested simplified methods in drill cores from areas of more heavily fractured bedrock than those analyzed in this study.
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Johansson, Björn. "Statistical Methods for Mineral Models of Drill Cores." Thesis, KTH, Matematisk statistik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-279848.
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In modern mining industry, new resource efficient and climate resilient methods have been gaining traction. Commissioned efforts to improve the efficiency of European mining is further helping us to such goals. Orexplore AB's X-ray technology for analyzing drill cores is currently involved in two such project. Orexplore AB wishes to incorporate geostatistics (spatial statistics) into their analyzing process in order to further extend the information gained from the mineral data. The geostatistical method implemented here is ordinary kriging which is an interpolation method that, given measured data, predicts intermediate values governed by prior covariance models. Ordinary kriging facilitates prediction of mineral concentrations on a continuous grid in 1-D up to 3-D. Intermediate values are predicted on a Gaussian process regression line, governed by prior covariances. The covariance is modeled by fitting a model to a calculated experimental variogram. Mineral concentrations are available along the lateral surface of the drill core. Ordinary kriging is implemented to sequentially predict mineral concentrations on shorter sections of the drill core, one mineral at a time. Interpolation of mineral concentrations is performed on the data considered in 1-D and 3-D. The validation is performed by calculating the corresponding density at each section that concentrations are predicted on and compare each such value to measured densities. The performance of the model is evaluated by subjective visual evaluation of the fit of the interpolation line, its smoothness, together with the variance. Moreover, the fit is tested through cross-validation using different metrics that evaluates the variance and prediction errors of different models. The results concluded that this method accurately reproduces the measured concentrations while performing well according to the above mentioned metrics, but does not outperform the measured concentrations when evaluated against the measured densities. However, the method was successful in providing information of the minerals in the drill core by producing mineral concentrations on a continuous grid. The method also produced mineral concentrations in 3-D that reproduced the measured densities well. It can be concluded that ordinary kriging implemented according to the methodology described in this report efficiently produces mineral concentrations that can be used to obtain information of the distribution of concentrations in the interior of the drill core.<br>I den moderna gruvindustrin har nya resurseffektiva och klimatbeständiga metoder ökat i efterfråga. Beställda projekt för att förbättra effektiviteten gällande den europeiska gruvdriften bidrar till denna effekt ytterligare. Orexplore AB:s röntgenteknologi för analys av borrkärnor är för närvarande involverad i två sådana projekt. Orexplore AB vill integrera geostatistik (spatial statistik) i sin analysprocess för att ytterligare vidga informationen från mineraldatan. Den geostatistiska metoden som implementeras här är ordinary kriging, som är en interpolationsmetod som, givet uppmätta data, skattar mellanliggande värden betingade av kovariansmodeller. Ordinary kriging tillåter skattning av mineralkoncentrationer på ett kontinuerligt nät i 1-D upp till 3-D. Mellanliggande värden skattas enligt en Gaussisk process-regressionslinje. Kovariansen modelleras genom att passa en modell till ett beräknat experimentellt variogram. Mineralkoncentrationer är tillgängliga längs borrkärnans mantelyta. Ordinary kriging implementeras för att sekventiellt skatta mineralkoncentrationer på kortare delar av borrkärnan, ett mineral i taget. Interpolering av mineralkoncentrationer utförs på datan betraktad i 1-D och 3-D. Valideringen utförs genom att utifrån de skattade koncentrationerna beräkna den motsvarande densiteten vid varje sektion som koncentrationer skattas på och jämföra varje sådant värde med uppmätta densiteter. Undersökning av modellen utförs genom subjektiv visuell utvärdering av interpolationslinjens passning av datan, dess mjukhet, tillsammans med variansen. Dessutom testas passformen genom korsvalidering med olika mätvärden som utvärderar varians- och skattningsfel för olika modeller. Slutsatsen från resultaten är att denna metod reproducerar de uppmätta koncentrationerna väl samtidigt som den presterar bra enligt de mätvärden som utvärderas, men överträffar ej de uppmätta koncentrationerna vid utvärdering mot de uppmätta densiteterna. Metoden var emellertid framgångsrik med att tillhandahålla information om mineralerna i borrkärnan genom att producera mineralkoncentrationer på ett kontinuerligt rutnät. Metoden producerade också mineralkoncentrationer i 3-D som reproducerade de uppmätta densiteterna väl. Slutsatsen dras att ordinary kriging, implementerad enligt den metod som beskrivs i denna rapport, effektivt skattar mineralkoncentrationer som kan användas för att få information om fördelningen av koncentrationer i det inre av borrkärnan.
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Farahat, Mohamed Shehata. "Theoretical and experimental investigations of roller cone bit tooth penetration." Thesis, Heriot-Watt University, 1991. http://hdl.handle.net/10399/799.
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Johnson, Reuben Carl. "Wetumpka impact structure modeled as the exposed remains of a large shallow water marine-target impact crater for analysis and interpretation of two drill cores taken from near the structure's geographic center." Auburn, Ala., 2007. http://repo.lib.auburn.edu/2007%20Spring%20Theses/JOHNSON_REUBEN_28.pdf.
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Duée, Cédric, Beate Orberger, Nicolas Maubec, et al. "Challenges in coupled on-line-on-mine-real time mineralogical and chemical analyses on drill cores." TU Bergakademie Freiberg, 2017. https://tubaf.qucosa.de/id/qucosa%3A23177.
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The SOLSA project aims to develop an innovative on-line-on-mine-real-time expert system, combining sonic drilling, mineralogical and chemical characterization and data treatment. Ideally, this combination, highly demanded by mining and metallurgical companies, will speed up exploration, mining and processing.
In order to evaluate the instrumental parameters for the SOLSA expert system, portable and laboratory analyses have been performed on four samples with contrasting lithologies: siliceous breccia, serpentinized harzburgite, sandstone and granite. More precisely, we evaluated the influence of the surface state of the sample on the signals obtained by portable X-Ray Fluorescence (pXRF) for chemistry and portable Infra-Red spectroscopy (pIR) for mineralogy. In addition, laboratory Raman spectroscopy, X-Ray Diffraction (XRD), XRF and ICP-OES laboratory analyses were performed to compare surface bulk mineralogical and chemical analyses.
This presentation highlights (1) the importance of coupling chemical and mineralogical analytical technologies to obtain most complete information on samples, (2) the effect of the sample surface state on the XRF and IR signals from portable instruments. The last point is crucial for combined instrumental on-line sensor design and the calibration of the different instruments, especially in the case of pXRF.
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Duée, Cédric, Beate Orberger, Nicolas Maubec, et al. "Challenges in coupled on-line-on-mine-real time mineralogical and chemical analyses on drill cores." Technische Universitaet Bergakademie Freiberg Universitaetsbibliothek "Georgius Agricola", 2018. http://nbn-resolving.de/urn:nbn:de:bsz:105-qucosa-231144.
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The SOLSA project aims to develop an innovative on-line-on-mine-real-time expert system, combining sonic drilling, mineralogical and chemical characterization and data treatment. Ideally, this combination, highly demanded by mining and metallurgical companies, will speed up exploration, mining and processing.
In order to evaluate the instrumental parameters for the SOLSA expert system, portable and laboratory analyses have been performed on four samples with contrasting lithologies: siliceous breccia, serpentinized harzburgite, sandstone and granite. More precisely, we evaluated the influence of the surface state of the sample on the signals obtained by portable X-Ray Fluorescence (pXRF) for chemistry and portable Infra-Red spectroscopy (pIR) for mineralogy. In addition, laboratory Raman spectroscopy, X-Ray Diffraction (XRD), XRF and ICP-OES laboratory analyses were performed to compare surface bulk mineralogical and chemical analyses.
This presentation highlights (1) the importance of coupling chemical and mineralogical analytical technologies to obtain most complete information on samples, (2) the effect of the sample surface state on the XRF and IR signals from portable instruments. The last point is crucial for combined instrumental on-line sensor design and the calibration of the different instruments, especially in the case of pXRF.
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Zhang, Yongsheng. "Aspects of reservoir evaluation and oil recovery." Laramie, Wyo. : [University of Wyoming], 2006. http://proquest.umi.com/pqdweb?did=1367831031&sid=2&Fmt=2&clientId=18949&RQT=309&VName=PQD.
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Ramos, Gustavo Zanco. "Otimização do Infill para redução das incertezas em um depósito sintético de cobre." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/44/44137/tde-27032017-111546/.
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A aquisição de novas informações de sondagem é realizada por intermédio do infill de furos de sonda e esta é uma prática utilizada em diversas etapas da exploração mineral. Métodos de otimização são largamente utilizados em várias fases e processos na vida da mina, por exemplo na otimização de cavas, na otimização do sequenciamento de lavra, entre outros. Contudo a utilização de métodos de otimização aplicados à locação de furos de inifill não é usual. Neste trabalho propõem-se utilizar a otimização matemática para melhorar a distribuição espacial dos novos furos, bem como para definir a quantidade adequada de furos a serem realizados. Métodos de otimização meta-heurísticos foram testados com o objetivo de minimizar duas funções objetivo que tratam das incertezas associadas à simulação dos dados, que são a soma da variância e a soma dos coeficientes de variação dos blocos simulados. O método que apresentou melhores resultados na otimização da função objetivo no menor tempo e custo computacional foi o método simulated annealing com resfriamento rápido e memória. Com base neste método de otimização comparou-se as funções objetivo propostas. Para efetuar a comparação amostraram-se os 11 furos definidos pela otimização para ambas as funções objetivo. O infill amostral foi realizado no corpo sintético e as comparações realizadas foram: a estatística descritiva - dos dados de infill comparados à população - e o gráfico Q-Q entre o e-type das simulações realizadas na base com infill e a população. A estatística descritiva do infill permitiu interpretar que a amostragem atualizada (soma das amostragens inicial e a nova) apresentou-se mais representativa do que a amostragem incial. Baseado no resultado dos gráficos Q-Q, a simulação calculada com o infill otimizando a minimização da soma dos coeficientes de variação apresentou maior aderência à população.<br>The acquisition of new drillhole information can be accomplished by the drill hole infill, a practice used in several steps of the mineral exploration. Optimization methods are widely used in several stages and processes of the mine life cycle, for example, mine pit optimization, mine scheduling optimization among others. However the optimization of drill hole infill locations are unusual. This work proposes the use of mathematical optimization to improve the spatial distribution and the number of the new drill holes to be made. Metaheuristics optimization methods were tested to minimize two objective functions that deal with the uncertainty associated to simulated data, the sum of the simulated blocks variance and the sum of the simulated blocks coefficient of variation. The best processing cost, processing time and results were obtained by simulated annealing method with fast cooling and memory for both objective functions. Based on this optimization method both proposed objective functions were compared. In order to perform the comparison 11 optimized drill holes locations by both objective functions were sampled. Sampling infill were done in the synthetic ore body and the made comparisons were: statistics - comparison between the infill data and population - and the QQ plot of the e-type statistics computed for simulation based on infill and population. Statistics for infill allowed to interpret that updated sample (the addition of new sampling in the initial data) was more representative than the initial sampling. Based on Q-Q plot the simulation computed for optimized infill location by the sum of the coefficient of variation minimization has more adherence to population.
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Glidewell, Jennifer Lynn King David T. "Petrographic investigation of selected samples from drill cores Eyreville A and Eyreville B Chesapeake Bay impact structure, Virginia /." Auburn, Ala, 2008. http://repo.lib.auburn.edu/EtdRoot/2008/SPRING/Geology_and_Geography/Thesis/Glidewell_Jennifer_39.pdf.
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Ferry, Mark Peter. "An evaluation of the sedimentology and the influence of grain size and facies on permeability for the White Rose A-17 cored interval, White Rose Oilfield, offshore eastern Newfoundland /." Internet access available to MUN users only, 2005. http://collections.mun.ca/u?/theses,16593.
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Gerják, Rastislav. "Návrh a konstrukce CNC routeru pro DPS." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2017. http://www.nusl.cz/ntk/nusl-319566.
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In mechanical industry, both additive and subtractive manufacturing methods are controlled by instructions in G-code, making it possible to utilize both technologies in one modular device. Main objective is to design, construct, and calibrate multipurpose machine based on RepRap 3D printer, which will be able to use attached spindle to precisely mill light materials. Particular emphasis is given to ability to carve a pattern and drill holes in plated substrate in order to create functional PCB by incision.
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Guiral, Vega Juan Sebastian. "Textural and Mineralogical Characterization of Li-pegmatite Deposit: Using Microanalytical and Image Analysis to Link Micro and Macro Properties of Spodumene in Drill Cores. : Keliber Lithium Project, Finland." Thesis, Luleå tekniska universitet, Mineralteknik och metallurgi, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-70422.
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Lithium represents one of the strategic elements for the rest of the 21st century due to its increasing demand in technological applications. Therefore, new efforts should be focused on the optimization of mineral characterization processes, which link the ore properties with its behaviour during downstream processes. These efforts should result in reducing operational risks and increasing resources utilization. The methodology presented in this study is based on the application of several classification techniques, aiming the mineral and textural characterization of two spodumene pegmatite deposits within the Keliber Lithium Project. Twelve textural classes have been proposed for the textual classification of the ore, which have been defined through the recognition of the main mineral features at macro- and micro-scale. The textural classification was performed through the application of drill core logging and scanning electron microscopy. Six classes are proposed to describe the characteristics of the spodumene ore. Six additional classes describe the main properties of the rocks surrounding the ore zone. Image analysis was implemented for the generation of mineral maps and the subsequent quantification of spodumene and Li2O within the analysed drill core images. The image segmentation process was executed in Fiji-ImageJ and is based on eight mineral classes and a set of seven feature extraction procedures. Thus, quantification of spodumene and Li2O is estimated by textural class. Hyperspectral images were used as a reference for assessing the estimations made through images analysis. A machine learning model in Weka allowed forecasting the behaviour of the twelve textural classes during spodumene flotation. This model is fed by metallurgical data from previous flotation tests and uses Random Forest classifier. The proposed methodology serves as an inexpensive but powerful approach for the complete textural characterization of the ore at Keliber Lithium Project. It provides information about: (1) mineral features at different scales, (2) spatial distribution of textures within the pegmatite body, (3) quantification of spodumene and Li2O within the drill cores and (4) processing response of each textural class. However, its application requires wide knowledge and expertise in the mineralogy of the studied deposits.<br><p>Thesis Presentation.</p><p>Textural and Mineralogical Characterization of Li-pegmatite Deposit: Using Microanalytical and Image Analysis to Link Micro and Macro Properties of Spodumene in Drill Cores. Keliber Lithium Project, Finland.</p><p></p>
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Kaba, Christina Marie. "Reconstructing long term sediment flux from the Brooks Range, Alaska, using edge clinoforms." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/88359.
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Thesis (S.M.)--Joint Program in Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences; and, the Woods Hole Oceanographic Institution), 2004.<br>Includes bibliographical references (p. 37-40).<br>Laterally extensive, well-developed clinoforms have been mapped in Early Cretaceous deposits located in the northeastern 27,000 km2 of the Colville Basin, North Slope of Alaska. Using public domain 2-D seismic data, well logs, core photographs, and grain size data, depositional geometries within the Nanushuk and Torok formations were interpreted in order to constrain the transport conditions associated with progradation of the shoreline and construction of the continental margin out of detritus shed from the ancestral Brooks Range. Using STRATA, a synthetic stratigraphic modeling package, constructional clinoform geometries similar to those preserved in the North Slope clinoform volume (32,400 km3) were simulated. Sediment flux, marine and nonmarine diffusivities, and basin subsidence were systematically varied until a match was found for the foreset and topset slopes, as well as progradation rates over a 6 million year period. The ability of STRATA to match the seismically interpreted geometries allows us to constrain measures of possible water and sediment discharges consistent with the observed development of the Early Cretaceous clinoform suite. Simulations indicate that, in order to reproduce observed geometries and trends using constant input parameters, the subsidence rate must be very small, only a fraction of the most likely rate calculated from the seismic data. Constant sediment transport parameters can successfully describe the evolution of the prograding margin only in the absence of tectonic subsidence. However, further work is needed to constrain the absolute magnitude of these values and determine a unique solution for the NPR-A clinoforms.<br>by Christina Marie Kaba.<br>S.M.
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Burefalk, Strauss Martin, and Samuel Rosko. "Fastställande av lineamentens karaktär med avseende på bergkvalitet enligt Qbas och RMRbas inför tunnel-konstruktion i Solna, Stockholm samt kvalitetsutvärdering av Astrock hyperdata report." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-295728.
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Sweden's population is increasing every year, which means that cities must adapt their infrastructure to be able to follow the demographic trend. In the current situation, Stockholm plans a major expansion of its metro network where evaluating the bedrock quality is of paramount importance. For the new SL metro connection project Gula linjen that stretches between Odenplan and Arenastaden in Solna, the company WSP has previously done quality surveys of the bedrock in the area and dimensioning of the reinforcements in the planned tunnels. Previous survey of the lineaments and weakness zones in the area has been done by means of core drilling and observations in the field. This study examines if the lineaments in the area are associated to any structures below ground surface in the bedrock by examining rock samples from drill cores. A digital presentation tool called Astrock hyperdata report is evaluated in this study by comparing manual measurements of the orientation of the joints in drill cores and the software´s measurements. The studied bedrock in the drill cores varies in quality from very poor to very good. Further examinations of zones of particularly poor rock quality done in this study suggest that the two identified lineaments have different characteristics. The north-west/south-east lineament which runs parallel to the planned metro route is indicated to represent the surface trace of a water-bearing fracture zone in the bedrock. The lineament with the E/W direction is dominated by structures and fault rocks, such as fault gouge and crushed rock in the drill cores, which indicates a brittle deformation zone. For the Gula linjen project, this information becomes useful as the underground reinforcements such as bolting and grouting have to<br>Sveriges befolkning ökar varje år, vilket gör att städer måste anpassas och expandera för att kunna följa den demografiska utvecklingen. I Stockholm planeras i dagsläget en stor utbyggnad av dess tunnelbanenätverk där det sker mycket arbete kring utvärdering av berggrunden för att göra detta möjligt. För Stockholms lokaltrafiks (SL) tunnelbaneprojektet Gula linjen som ska gå mellan Odenplan och Solna har företaget WSP tidigare gjort kvalitetsundersökningar av berggrunden i området samt dimensioneringar av förstärkningar i de planerade tunnlarna. Studier av svaghetzoner och lineamenten i området har gjorts med hjälp av kärnborrning och fältobservationer. Denna studie undersöker om lineamenten som finns i området är kopplade till strukturer längre ner i berggrunden genom att undersöka bergprov i form av borrkärnor. Som komplement har det digitala redovisningsverktyget Astrock hyperdata report använts för att kunna jämföra strukturer i berget med de egna mätningarna i studien. Programmet kommer även att utvärderas i studien. De erhållna värdena från undersökningen på borrkärnorna varierar i kvalitet från väldigt dålig till väldigt bra. Närmare studier på zoner av särskilt dålig kvalitet tyder på att de båda lineamenten karaktäriseras av olika typer av strukturer. Det nordväst-/sydöstliga lineamentet, som går parallellt med den planerade tunnelbanesträckan, domineras av strukturer som tyder på att lineamentet representerar en vattenförande sprickzon under markytan. I lineamentet med öst-västlig riktning dominerar strukturer som tyder på förekomsten av en förkastningszon. För projektet Gula linjen blir denna information användbar då den vattenförande sprickzonen kan innebära att tunnelförstärkning med injektering måste göras för ytterligare skydd mot vatteninträngning.
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Škapová, Pavla. "Problematika testování stříkaných betonů." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2014. http://www.nusl.cz/ntk/nusl-226742.
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The master‘s thesis focuses on testing the shotcrete prepared in laboratory conditions. The main observed properties are compresive strenght of shotcrete and modulus of elasticity. The aim is assessment of methods for measuring those parameters. The calibrating correlations for strenght characteristics of shotcrete are given by obtaining the results of used methods. The shotcrete composition, amount and type of accelerating additive as well as economic aspect of using shotcrete is also assessed.
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Quéméneur, Philippe. "Caractérisation géotechnique en zone d"offshore" profond et analyse régionale de la stabilité des pentes : application à quelques secteurs de la pente continentale du golfe de Guinée." Vandoeuvre-les-Nancy, INPL, 1996. http://www.theses.fr/1996INPL073N.
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Deux campagnes océanographiques ont été réalisées en 1992 et 1993 par Ifremer and Elf Aquitaine Production, dans le golfe de Guinée, avec des prélèvements de carottes küllenberg et l'acquisition de données géophysiques par grandes profondeurs d'eau. Les essais géotechniques, réalisés au laboratoire de géotechnique de l'E. N. S. G. , ont permis une description synthétique des sédiments superficiels sur les talus continentaux du Nigeria, du Gabon et du Congo. Sur la pente continentale du Gabon, ces résultats mettent en évidence un état sous-consolidé en profondeur. Les relevés géophysiques y indiquent l'existence de figures d'expulsion de fluides et de zones de sédiments superficiels chargés en gaz. Un réflecteur acoustique profond de trente mètres est interprété comme une surface de glissement potentiel, ou le facteur de sécurité non drainé semble à un minimum. La prise en compte de la bathymétrie et des critères de stabilité ont permis une cartographie régionale du risque et une interprétation des désordres identifies par la géophysique: les résultats confirment que ces désordres correspondent à un état remanié en profondeur ou à la migration de fluides interstitiels ; nous avons calibré l'impact de différents modes d'action des fluides interstitiels sur la stabilité des sédiments. Les essais géotechniques ont donc apporté une caractérisation systématique et synthétique des sédiments prélevés dans le golfe de Guinée. La juxtaposition d'informations géophysiques et géotechniques a permis d'inventorier, de calibrer et de localiser les causes de désordres dans la zone Gabon ; toutefois, une meilleure connaissance des processus gravitaires dans cette zone passerait par l'étude locale des phénomènes identifiés et l'acquisition de mesures in situ: mesures de la fraction gazeuse, des excès de pression interstitielle et des contraintes effectives verticales
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Delmotte, Marc. "Enregistrements climatiques à Law Dome : variabilité pour les périodes récentes et pour la déglaciation." Phd thesis, Grenoble 1, 1997. http://tel.archives-ouvertes.fr/tel-00759854.
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La complexité du système climatique nécessite de recourir à une grande variété d'indicateurs pour reconstruire ses variations passées. A ce titre, les glaces polaires constituent un outil d'investigation privilégié compte tenu de la grande diversité d'informations qu'elles recèlent. Dans cette étude, nous nous intéressons plus particulièrement au forage antarctique côtier de DSS, sur le site du Law-Dome et aux indicateurs climatiques que constituent les teneurs isotopiques et la teneur en air de la glace. Le nombre d'analyses et la précision des mesures isotopiques requises pour l'étude d'un forage polaire demandent une adaptation et une mise en oeuvre spécifique des techniques classiques de spectrométrie de masse. Notre étude présente une technique nouvelle et originale d'injection des échantillons mise au point sur l'un des spectromètre de masse du laboratoire; elle a permis d'accroître sensiblement le rendement de l'appareil en conservant la précision expérimentale. Récemment de nouvelles études ont remis en cause l'interprétation quantitative classique des isotopes en termes de température. L'analyse de nouveaux échantillons de neige de surface sur la zone de l'Antarctique de l'Est nous permet de discuter la validité de la relation spatiale isotope/température et de proposer une estimation de l'erreur associée. L'utilisation de l'excès en deutérium et d'un modèle isotopique simple apportent une information supplémentaire sur l'origine des précipitations actuelles. Face aux interrogations sur l'impact des activités humaines sur le climat, il est essentiel de replacer les fluctuations récentes dans la cadre de la variabilité climatique naturelle. L'unique résolution temporelle offerte par le forage de DSS nous permet d'étudier en détail le climat des 4000 dernières années. L'analyse spectrale des enregistrements suggère l'existence de modes oscillatoires à rapprocher des phénomènes ENSO et/ou de l'onde circumpolaire antarctique. L'analyse de la teneur en air des échantillons de DSS nous apporte enfin une information sur les variations d'altitude probablement subies par le LawDome au cours de la dernière transition climatique.
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Basile, Isabelle. "Origine des aérosols volcaniques et continentaux de la carotte de glace de Vostok (Antarctique)." Phd thesis, Grenoble 1, 1997. http://tel.archives-ouvertes.fr/tel-00756041.
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Déposés en Antarctique de l'Est au cours des 4 derniers cycles climatiques, les aérosols volcaniques (5-50 )um) et continentaux (2-3 )um) de la carotte de Vostok constituent des traceurs de circulations atmosphériques passées. Pour reconstruire leurs trajectoires troposphériques, il est nécessaire d'identifier les sources (volcans ou régions désertiques) à l'origine des émissions des cendres et des poussières continentales. Pour cela, on compare les caractéristiques géochimiques des aérosols avec les caractéristiques des sources potentielles répertoriées. Ces analyses reposent sur les concentrations en éléments majeurs (obtenues par microsonde électronique), en éléments traces (ICPMS), et sur les compositions isotopiques en Strontium et Néodyme (TIMS). Nous avons dû adapter ces méthodes analytiques à la petite taille des aérosols et à leur très faible quantité. Les caractéristiques géochimiques des volcans sources potentiels (latitude>30oS, activité<-500 ka) sont basées sur une synthèse bibliographique. On montre que les cendres des horizons volcaniques analysés proviennent essentiellement de l'arc volcanique des îles Sandwichs (situé dans l'Atlantique Sud, à 5000 km), mais aussi d'Antarctique de l'Ouest et d'Amérique du Sud. De plus, certains horizons peuvent être utilisés comme marqueurs stratigraphiques pour dater (e.g. 141 ka) et corréler les carottes. Les caractéristiques isotopiques (Sr et Nd) des régions désertiques d'Afrique du Sud, d'Australie, du Sud de l'Amérique du Sud, d'Antarctique et de Nouvelle Zélande sont mesurées sur des échantillons prélevés in situ. On remarque qu'il est nécessaire d'utiliser, pour la comparaison avec les aérosols, la fraction granulométrique inférieure à 5 um. Il est ainsi montré que les poussières continentales déposées à Vostok au cours des 4 derniers cycles climatiques proviennent de la Patagonie en période interglaciaire (flux -1,5 mg/m2/an) comme en période glaciaire (flux -20 mg/m2/an). Une partie de cette augmentation de flux peut être expliquée par la présence de vastes épandages de particules détritiques fluvio-glaciaires qui recouvrent, en période glaciaire, la Patagonie et le plateau continental argentin émergé. L'ensemble des sources des aérosols volcaniques et continentaux est donc localisé, quelle que soit la période climatique, dans une région située du côté Atlantique de l'Antarctique, aux moyennes et hautes latitudes. Le transport des particules semble quant à lui être assuré par un courant d'ouest circumpolaire convergent versl'Antarctique. Ce travail montre donc que, à partir des aérosols volcaniques et continentaux, on peut obtenir des paléo-informations dynamiques qui, au travers des corrélations, des datations, ou des modèles de circulation atmosphérique globaux, seront utiles aux reconstitutions des climats du passé.
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Krinner, Gerhard. "Simulations du climat des calottes de glace." Phd thesis, Université Joseph Fourier (Grenoble), 1997. http://tel.archives-ouvertes.fr/tel-00716408.
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Ce travail traite de la simulation numérique du climat des grandes calottes de glace, en particulier des calottes de l'Antarctique et du Groenland, toujours existantes, dans des conditions climatiques différentes, à l'aide de modèles de circulation générale de l'atmosphère (MCGA). Le MCGA à grille variable LMDz a été adapté aux spécificités du climat polaire et validé pour le climat actuel. L'approche d'une grille variable, qui permet d'utiliser le MCGA à haute résolution spatiale (autour de 100 km) sur la région d'intérêt à un coût numérique raisonnable, a été validée en analysant la dynamique atmosphérique au bord de la région ciblée à l'aide d'un schéma de suivi des cyclones individuels. Des simulations du climat du Dernier Maximum Glaciaire (DMG) ont été faites pour le Groenland et l'Antarctique et analysées en tenant compte des archives glaciaires disponibles. Une explication possible des différences entre les deux méthodes principales de reconstruction des paléotempératures - l'analyse des isotopes de l'eau et la mesure directe de la température de la glace dans le trou de forage - au centre du Groenland a pu être proposée. Cette explication est basée sur des changements de paramètres climatiques locaux. C'est la première fois que l'approche de grille variable a été utilisée dans un MCGA pour des simulations du climat polaire à l'échelle de quelques années. Les simulations paléoclimatiques faites avec LMDz sont à une résolution spatiale inégalée à ce jour. Finalement, le climat du DMG, simulé par plusieurs MCGA dans le cadre du projet international PMIP (Paleoclimate Modelling Intercomparison Programme), a été analysé, et des implications des résultats pour l'interprétation des enregistrements glaciaires ont été discutées.
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LI, ZHEN-LIN, and 李展霖. "Study of adjustable step-core drill for drilling composite materials." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/25542807482344897381.
Full textAbstract:
碩士<br>大華科技大學<br>機電研究所<br>104<br>Drilling is extremely important processing for carbon fiber-reinforced composite materials. Carbon fiber-reinforced composite material have high hardness, high strength, thermal conductivity of poor and low interlaminar strength characteristics of difficult machining materials. General drilling carbon fiber-reinforced composite materials in industrial applications experience prone to layered, torn, delamination defects, and most occurred in the exit hole, tearing and produced by drilling of burr edge sharp enough, resulting in carbon fiber-reinforced composite materials not completely cut off. The object of this study is to develop an adjustable step-core drill for drilling carbon fiber-reinforced composite materials, which is to verify the feasibility of this new tool design. This new drill apart from adjusting the elongation can also make worn tool replacement as well as two various drilling can be carried out in single trip.
In this study, the twist drill, inner-outer drill (3) and inner-outer drill (4) were selected for the drilling research. From the experimental results showed that the thrust of twist drill is larger than the inner-outer drill (3) and inner-outer drill (4) because this design tool was longer. It is more suitable for low-CNC spindle speed (1000 rpm) and low feed rate (30 mm/min) in drilling composites. As to the inner drill elongation of the amount, it will affect the thrust force of the size of its drilling. Within or close to the drill thickness of composite materials as a priority consideration, which can reduce thrust when tungsten twist drill within the composite, followed by the outer drill drilling composites induced thrust force generated. This study was designed by an adjustable drilling tool in drilling different experiments. Verifiable adjustable step drill for drilling carbon fiber-reinforced composite materials is feasible.
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Tshepiso, Mothlele. "Boundary determination of mineral regions in hyperspectral drill core imager data." Thesis, 2017. https://hdl.handle.net/10539/24950.
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A dissertation submitted to the Faculty of Science, University of the Witwatersrand, in fulfillment of the requirements for the degree of Master of Science, 2017<br>This work is about segmentation of hyperspectral images in order to identify the different regions within the image and determine their best boundaries. A new method based on the Fitzhugh-Nagumo model is introduced to do this by extracting additional useful information from the image data. It is inspired by the work done in [1] titled “A novel approach to text binarization via a diffusion-based model”, which was applied on 2-dimensional images in grayscale. The results from the proposed method is then assessed and compared to other existing methods on a scene of Cuprite, Nevada, as well as drill core imager data. The datasets chosen for this research are the artificial and real AVIRIS Cuprite of Nevada and as well as real drill core imager data. Cuprite, Nevada was chosen because it is well studied and other methods have been applied to it. The core imager data is studied due to its importance of delineating minerals regions and the likelihood of getting purer pixels given the high spatial resolution of the data.<br>XL2018
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Huang, Hsu Chun, and 黃昫鈞. "The Effect of Core Muscle Training on Core Muscular Fitness and Tennis Drill Performances for College Male Tennis." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/57246417344528976028.
Full textAbstract:
碩士<br>正修科技大學<br>休閒與運動管理所<br>103<br>Purpose: The purpose of this study was to investigate the effects of core muscle training on collegiate male tennis players’ core muscle fitness and tennis drill. Method: A total of 24 collegiate male tennis players were recruited as participants (Age: 21.9 ± 1.9 years; Height: 175.1 ± 5.6 cm; Weight: 70.7 ± 9.5 kg; Years of training: 5.1±1.5 years. The 24 participants were randomly divided into the control group (n = 12) and experimental group (n = 12). The experimental group underwent 8 weeks (3 times/week, 60 minutes/session) of core muscle training in addition to their regular training schedule. The pre and post core muscle fitness and tennis drill tests conducted on the experimental group’s participants were analyzed with paired sample t-test to examine differences between the pre and post training data. The data collected from both the control and experimental group was analyzed using Analysis of Covariance (ANCOVA) to assess the difference between groups (α =.05). Results: After the experimental group underwent 8 weeks of core muscle training , the types of core muscle fitness that revealed significant difference were the isometric abdominal muscle endurance, isometric back muscle endurance, dynamic abdominal muscle endurance,and dynamic back muscles endurance(p < .05). The accuracy of tennis drill that revealed significant difference were the fixed backhand crosscourt, moving forehand crosscourt and down-the-line, moving backhand crosscourt and down-the-line, and the left service box ( p < .05). The ball speed of the fixed forehand crosscourt and down-the-line, fixed backhand crosscourt and down-the-line, moving forehand down-the-line, moving backhand crosscourt, and both sides of service revealed significant differences (p < .05). Conclusion: It is evident that core muscle training enhances the core muscle fitness and tennis drill of collegiate male tennis players.
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Youn, Heejung 1976. "Effect of verification core hole on the point bearing capacity of drilled shafts." 2008. http://hdl.handle.net/2152/18183.
Full textAbstract:
For many projects involving drilled shafts, cores are required to be taken below the shaft base for visual identification of the underlying material. For example, the Texas Department of Transportation (TxDOT) requires a core length of at least 1.5 m (5 ft) or equal to the shaft diameter, whichever is greater, at the shaft base. Although the verification cores are to be extracted at the shaft base, The Department of Transportation of many states do not provide guidance to eliminate the effect of the verification core on the point bearing capacity. A recent study shows that the verification core hole is either filled with concrete in dry condition or with sand-gravel mixture in wet pour (Raibagkar, 2008). This finding is crucial because the point bearing capacity of drilled shafts with an empty hole at the base should be significantly lower than that of drilled shafts without verification core. Although the materials that fill in the verification core remove the risk of losing large point bearing capacity, the exposure of the core holes to air-drying may have an adverse effect on the point bearing capacity tipped in clay shales, especially when the basal material is susceptible to weathering. Therefore, the effect of the verification core on the point bearing capacity has been thoroughly investigated with emphasis on changes in the material properties of four clay shales (Del Rio Clay, Eagle Ford Shale, Taylor Marl, and Navarro Shale) in central Texas. The effect of verification core on the point bearing capacity of drilled shafts was investigated using finite element method (FEM) software, PLAXIS. The results from laboratory tests were converted to input material parameters for Mohr-Coulomb failure criterion, and the thickness of degraded zone around the core was interpreted from fullscale condition degradation tests. The load-displacement curves at the shaft base were created from PLAXIS analyses, and the point bearing capacities were obtained at 5%D and 10%D displacement from load-displacement curves. These capacities were used to calculate reduction factors that relate the point bearing capacity of the reference model (without a verification core) with that of the “core models” (with a verification core). The reduction factors are good indicators to determine if verification core had a positive or negative effect on the point bearing capacity. It was found that the reduction in point bearing capacity of “core models” is typically within 10% capacity of the reference model, and a maximum reduction of 14% was found for the Taylor Marl that was dried for 48 hours.<br>text
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Vermeul, Vincent R. "A method for quantifying macroporosity." Thesis, 1990. http://hdl.handle.net/1957/37965.
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Almasoumi, Abdullah Muhammad Sultan. "Monte Carlo model of a capture gamma ray analyzer for a seafloor core sample." Thesis, 1989. http://hdl.handle.net/1957/38226.
Full textAbstract:
Of great benefit, but not limited to seafloor mineral
exploration, is a technique that fairly rapidly determines the
composition of a drilled vibracore (in a time comparable to the time
involved in obtaining the core). The rapid assessment is desired to
predict whether a given region warrants further exploration by
coring.
A proposed monitoring system, based on neutron capture gamma
ray analysis, consists of a container tank filled with water and
tubular extensions that house a Cf-252 neutron source and a
detector positioned within the tank. The core sample is passed
through the system in stop and count steps. The net count rates, due
to "signature" capture gamma rays from neutron capture in elements
in the core sample, are proportional to the amount of the element
responsible for emitting the capture gamma ray.
The proposed system was modeled and simulated by the Monte Carlo
method to predict the relationship between the response of the
detector and the elemental concentrations within the sample.
Accurate and detailed treatment of neutron transport and gamma ray
production and attenuation within the system were employed not only
to predict the relationship of the photopeak responses with respect
to elemental concentrations, but also to permit investigation of the
design parameters and structural material changes in the system.
The developed Monte Carlo code utilizes a variety of variance
reduction techniques, such as implicit absorption with Russian
Roulette and deterministic production of the gamma rays of interest,
along with a form of correlated sampling to predict simultaneously
the responses over a range of interest of the elemental
concentrations. The predicted results were compared with predictions
obtained from a well established general purpose Monte Carlo code
(MCNP).<br>Graduation date: 1990