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[{"key": "dc.contributor.advisor", "value": "Kataja, Markku", "language": "", "element": "contributor", "qualifier": "advisor", "schema": "dc"}, {"key": "dc.contributor.author", "value": "Tanttu, Joni", "language": "", "element": "contributor", "qualifier": "author", "schema": "dc"}, {"key": "dc.date.accessioned", "value": "2020-04-28T07:03:29Z", "language": null, "element": "date", "qualifier": "accessioned", "schema": "dc"}, {"key": "dc.date.available", "value": "2020-04-28T07:03:29Z", "language": null, "element": "date", "qualifier": "available", "schema": "dc"}, {"key": "dc.date.issued", "value": "2020", "language": "", "element": "date", "qualifier": "issued", "schema": "dc"}, {"key": "dc.identifier.uri", "value": "https://jyx.jyu.fi/handle/123456789/68729", "language": null, "element": "identifier", "qualifier": "uri", "schema": "dc"}, {"key": "dc.description.abstract", "value": "T\u00e4m\u00e4n tutkielman tavoitteena oli jatkokehitt\u00e4\u00e4 kokeellista menetelm\u00e4\u00e4, jossa kastumisen seurauksena tyhj\u00e4\u00e4n tilaan laajenevan bentoniitti nimisen savimateriaalin homogenisaatiota seurataan r\u00f6ntgenkuvauksen avulla. Menetelm\u00e4ll\u00e4 mitataan turpoavan bentoniitin muodon- ja tiheydenmuutoksia sek\u00e4 paisuntapainetta. Muodon- ja tiheysmuutosten laskenta perustuu numeeriseen r\u00f6ntgenkuvien analysoimiseen, jossa r\u00f6ntgenkuvia verrataan pikseli pikselilt\u00e4 edellisiin referenssikuviin. Menetelm\u00e4 tarjoaa kokeellista dataa, jota voidaan hy\u00f6dynt\u00e4\u00e4 ydinj\u00e4tteen loppusijoittamiseen k\u00e4ytett\u00e4v\u00e4n bentoniittipuskurin k\u00e4yt\u00f6smallien luomiseen ja validointiin.\n\t\nR\u00f6ntgenkuvien pikselikohtainen harmaans\u00e4vyarvo ja r\u00f6ntgens\u00e4teilyn lineaarinen vaimenemiskerroin riippuvat materiaalista ja sen tiheydest\u00e4. Kastuessaan bentoniitin r\u00f6ntgenkuvien harmaans\u00e4vyarvot muuttuvat johtuen veden osatiheyden kasvusta. Paikallisista harmaans\u00e4vyjen muutoksista pystyt\u00e4\u00e4n t\u00e4ten arvioimaan bentoniitin ja veden osatiheyksien muutokset tutkittavassa bentoniittin\u00e4ytteess\u00e4. Tutkittaviin bentoniittin\u00e4ytteisiin on lis\u00e4tty merkkipartikkeleita, joiden siirtymi\u00e4 seuraamalla saadaan selville bentoniitin muodonmuutoskentt\u00e4 kastelun aikana.\n\t\nT\u00e4ss\u00e4 tutkielmassa on esitelty yhteens\u00e4 kymmenen sylinterim\u00e4isen (halkaisija: 20 mm ja korkeus: 10 mm) bentoniittin\u00e4ytteen 16 vuorokauden kastelun mittaussarja. Bentoniittin\u00e4ytteiden kuivatiheydet olivat joko 1,4 g/cm^3 tai 1,8 g/cm^3 ja n\u00e4ytteit\u00e4 kasteltiin NaCl + CaCl2, NaCl ja CaCl2 suolaliuoksilla kolmella eri ionivahvuudella (3,5 mmol, 489 mmol ja 975 mmol). Mittaussarja koostui yhteens\u00e4 kymmenest\u00e4 kuvausvaiheesta. Kuvausvaiheiden aikana suoritettiin samanaikaisesti kalibraatio- ja n\u00e4ytekuvien ker\u00e4\u00e4miset. Kuvien analysointi toteutettiin numeerisesti MATLAB-ohjelmalla.\n\t\nMenetelm\u00e4n kehityksen aikana huomattiin, ett\u00e4 merkitt\u00e4vin virhel\u00e4hde puolivapaasti laajenevalle bentoniittin\u00e4ytteelle on sen hyvin nopea paisuminen kastelun alkuvaiheessa. Turpoamisen nopeus vaikuttaa r\u00f6ntgenkuvien tarkkuuteen erityisesti kastelun alussa, jolloin harmaans\u00e4vyarvojen laskennasta aiheutuu tarpeetonta kohinaa my\u00f6s muodonmuutos- ja tiheyskent\u00e4n laskuihin. Ongelma on tutkielmassani ratkaistu toteuttamalla kuvien analysoiminen my\u00f6s k\u00e4\u00e4nteisesti eli integroimalla ajassa taaksep\u00e4in lopputilasta alkutilaan. Eteen- ja taaksep\u00e4iset aikaintegraatiot yhdistet\u00e4\u00e4n v\u00e4hemm\u00e4n kohinaa sis\u00e4lt\u00e4v\u00e4ksi lopputulokseksi. Taaksep\u00e4inen aikaintegraatio olettaa kuitenkin bentoniittin\u00e4ytteiden lopputilan olevan t\u00e4ysin saturoitunut, mik\u00e4 on tulosten perusteella paikoitellen kyseenalainen oletus.\n\t\nYleisesti ottaen t\u00e4ss\u00e4 tutkielmassa esitelt\u00e4v\u00e4 r\u00f6ntgenkuvaukseen perustuva kokeellinen menetelm\u00e4 on vankka ja toistettavuudeltaan erinomainen bentoniitin kaltaisen kemoelastisen savimateriaalin homogenisaatioasteen tutkimiseen. Menetelm\u00e4n kehitt\u00e4misell\u00e4 on pyritty antamaan tietotaitoa tuleviin bentoniittitutkimuksiin ja saavuttamaan paras mahdollinen mittaustarkkuus nykyisell\u00e4 jo kehityst\u00e4 j\u00e4ljess\u00e4 olevalla r\u00f6ntgenkuvauslaitteistolla.", "language": "fi", "element": "description", "qualifier": "abstract", "schema": "dc"}, {"key": "dc.description.abstract", "value": "The aim of this thesis was to further develop an experimental method where wetting induced free swelling and homogenization process of clay material called bentonite is monitored with X-ray imaging. The method is used to measure deformation, partial density changes and swelling pressure experienced by bentonite throughout the irrigation process. Calculations of the measured quantities is based on numerical X-ray image analysis, in which the X-ray images of the sample are compared pixel by pixel with the previous reference X-ray images. The method provides experimental data that can be used to create and validate computational models for a bentonite buffer used in nuclear waste disposal.\n\t\nThe pixel specific gray scale value and X-ray linear attenuation coefficient depends on the material and its density. When wetted, gray scale values in bentonite X-ray images change due to rise in partial density of water. Local changes in gray scale values can thus be used to estimate changes in the density of bentonite and water in the measured bentonite sample. In addition, marker particles have been added to the bentonite samples. Position changes of these particles between the images are used to define the deformation field of the sample.\n\t\nThis paper presents a 16-day irrigation measurement series of a total of ten cylindrical (diameter: 20 mm and height: 10 mm) bentonite samples. The dry densities of bentonite samples were either 1.4 g/cm^3 or 1.8 g/cm^3 and the samples were wet by NaCl + CaCl2, NaCl and CaCl2 water solutions at three different ionic strengths (3.5 mmol, 489 mmol and 975 mmol). The measurement series consisted of a total of ten phases. During the imaging steps, calibration and sample images were collected simultaneously. The image analysis was performed numerically with MATLAB software.\n\t\nDuring the development of the method, it was noticed that the most significant source of uncertainty for a semi-freely expanding bentonite sample is its very rapid initial expansion. The swelling rate affects the resolution of the X-ray images, especially at the beginning of the irrigation, whereby the calculation of the gray scale values also causes unnecessary noise to the deformation and density field calculations. In my thesis this problem has been solved by implementing the analysis of the images also in reverse order, i.e. integrating backwards in time from end state to initial state. The forward and backward time integrations can eventually be combined to give a better, less noisier, overall result. However, the backward integration assumes that the final state of the bentonite samples is fully saturated, which is sometimes a questionable assumption based on the results.\n\t\nIn general, the X-ray based experimental method presented in this study is a robust and reproducible method for studying the degree of homogenization of bentonite-like chemoelastic clay material. The development of the method has been aimed at providing know-how for future bentonite studies and at achieving the best possible measurement accuracy with current post-development X-ray imaging equipment.", "language": "en", "element": "description", "qualifier": "abstract", "schema": "dc"}, {"key": "dc.description.provenance", "value": "Submitted by Paivi Vuorio (paelvuor@jyu.fi) on 2020-04-28T07:03:29Z\nNo. of bitstreams: 0", "language": "en", "element": "description", "qualifier": "provenance", "schema": "dc"}, {"key": "dc.description.provenance", "value": "Made available in DSpace on 2020-04-28T07:03:29Z (GMT). No. of bitstreams: 0\n Previous issue date: 2020", "language": "en", "element": "description", "qualifier": "provenance", "schema": "dc"}, {"key": "dc.format.extent", "value": "90", "language": "", "element": "format", "qualifier": "extent", "schema": "dc"}, {"key": "dc.format.mimetype", "value": "application/pdf", "language": null, "element": "format", "qualifier": "mimetype", "schema": "dc"}, {"key": "dc.language.iso", "value": "fin", "language": null, "element": "language", "qualifier": "iso", "schema": "dc"}, {"key": "dc.rights", "value": "In Copyright", "language": "en", "element": "rights", "qualifier": null, "schema": "dc"}, {"key": "dc.title", "value": "Kastuvan bentoniitin muodonmuutosten ja vesipitoisuuden aikakehityksen mittaaminen r\u00f6ntgenkuvauksen avulla", "language": "", "element": "title", "qualifier": null, "schema": "dc"}, {"key": "dc.type", "value": "master thesis", "language": null, "element": "type", "qualifier": null, "schema": "dc"}, {"key": "dc.identifier.urn", "value": "URN:NBN:fi:jyu-202004282932", "language": "", "element": "identifier", "qualifier": "urn", "schema": "dc"}, {"key": "dc.type.ontasot", "value": "Pro gradu -tutkielma", "language": "fi", "element": "type", "qualifier": "ontasot", "schema": "dc"}, {"key": "dc.type.ontasot", "value": "Master\u2019s thesis", "language": "en", "element": "type", "qualifier": "ontasot", "schema": "dc"}, {"key": "dc.contributor.faculty", "value": "Matemaattis-luonnontieteellinen tiedekunta", "language": "fi", "element": "contributor", "qualifier": "faculty", "schema": "dc"}, {"key": "dc.contributor.faculty", "value": "Faculty of Sciences", "language": "en", "element": "contributor", "qualifier": "faculty", "schema": "dc"}, {"key": "dc.contributor.department", "value": "Fysiikan laitos", "language": "fi", "element": "contributor", "qualifier": "department", "schema": "dc"}, {"key": "dc.contributor.department", "value": "Department of Physics", "language": "en", "element": "contributor", "qualifier": "department", "schema": "dc"}, {"key": "dc.contributor.organization", "value": "Jyv\u00e4skyl\u00e4n yliopisto", "language": "fi", "element": "contributor", "qualifier": "organization", "schema": "dc"}, {"key": "dc.contributor.organization", "value": "University of Jyv\u00e4skyl\u00e4", "language": "en", "element": "contributor", "qualifier": "organization", "schema": "dc"}, {"key": "dc.subject.discipline", "value": "Soveltava fysiikka", "language": "fi", "element": "subject", "qualifier": "discipline", "schema": "dc"}, {"key": "dc.subject.discipline", "value": "Applied Physics", "language": "en", "element": "subject", "qualifier": "discipline", "schema": "dc"}, {"key": "yvv.contractresearch.funding", "value": "0", "language": "", "element": "contractresearch", "qualifier": "funding", "schema": "yvv"}, {"key": "dc.type.coar", "value": "http://purl.org/coar/resource_type/c_bdcc", "language": null, "element": "type", "qualifier": "coar", "schema": "dc"}, {"key": "dc.rights.accesslevel", "value": "openAccess", "language": null, "element": "rights", "qualifier": "accesslevel", "schema": "dc"}, {"key": "dc.type.publication", "value": "masterThesis", "language": null, "element": "type", "qualifier": "publication", "schema": "dc"}, {"key": "dc.subject.oppiainekoodi", "value": "4023", "language": "", "element": "subject", "qualifier": "oppiainekoodi", "schema": "dc"}, {"key": "dc.subject.yso", "value": "bentoniitti", "language": null, "element": "subject", "qualifier": "yso", "schema": "dc"}, {"key": "dc.subject.yso", "value": "r\u00f6ntgens\u00e4teily", "language": null, "element": "subject", "qualifier": "yso", "schema": "dc"}, {"key": "dc.subject.yso", "value": "kokeelliset menetelm\u00e4t", "language": null, "element": "subject", "qualifier": "yso", "schema": "dc"}, {"key": "dc.subject.yso", "value": "vesipitoisuus", "language": null, "element": "subject", "qualifier": "yso", "schema": "dc"}, {"key": "dc.format.content", "value": "fulltext", "language": null, "element": "format", "qualifier": "content", "schema": "dc"}, {"key": "dc.rights.url", "value": "https://rightsstatements.org/page/InC/1.0/", "language": null, "element": "rights", "qualifier": "url", "schema": "dc"}, {"key": "dc.type.okm", "value": "G2", "language": null, "element": "type", "qualifier": "okm", "schema": "dc"}]
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