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Pluoštinių priedų įtaka autoklavinio akytojo betono savybėms / The Influence of Fiberous Additives on the Properties of Autoclaved Aerated ConcreteMikulskis, Donatas 29 June 2007 (has links)
Disertacijoje nagrinėjama pluoštinių priedų įtaka autoklavinio akytojo betono (AAC) savybėms, ištirta pluoštinių priedų korozija šarminėje aplinkoje, nustatyta pluoštinių priedų įtaka AAC formavimo mišiniams, parinkta optimali formavimo mišinių sudėtis, sumaišymo ir pluoštų parametrai. Atlikta pluoštinių priedų hidrofilizacija ir ištirta jos įtaka portlandcemečio hidratacijai bei pluoštų pasiskirstymui AAC matricoje. Nustatytos AAC bandinių su pluoštiniais priedais bandinių fizikinės mechaninės charakteristikos, ištirta pluoštų sąlyčio zona su AAC matrica, nustatyta drėgnio įtaka AAC savybėms ir šalčio atsparumas. Disertacijoje pateikta patobulinta AAC gamybos technologinė schema. / Dissertation analizes The Influence of Fiberous Additives on the Properties of Autoclaved Aerated Concrete (AAC). The corrosion of fibers in alkaline medium and the resistance to hydrothermal exposure was investigate, the optimal composition of formation admixtures and its parameters of mixing was selected, optimal quantities and parameters of fibrous admixture was determined, the effect of surface active agents (SAA) used for hydrophilization of fibers on hydration of Portland cement was investigate to. The effect of fibrous admixtures on properties of AAC products (density, macro- and microstructure, reinforcing fibrous admixture – AAC matrix contact zone, compression strength, bending strength, freeze resistance) was determined. A new modernized technological scheme to produce AAC is presented in this dissertation.
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Pluoštinių priedų įtaka autoklavinio akytojo betono savybėms / The Influence of Fiberous Additives on the Properties of Autoclaved Aerated ConcreteMikulskis, Donatas 29 June 2007 (has links)
Disertacijoje nagrinėjama pluoštinių priedų įtaka autoklavinio akytojo betono (AAC) savybėms, ištirta pluoštinių priedų korozija šarminėje aplinkoje, nustatyta pluoštinių priedų įtaka AAC formavimo mišiniams, parinkta optimali formavimo mišinių sudėtis, sumaišymo ir pluoštų parametrai. Atlikta pluoštinių priedų hidrofilizacija ir ištirta jos įtaka portlandcemečio hidratacijai bei pluoštų pasiskirstymui AAC matricoje. Nustatytos AAC bandinių su pluoštiniais priedais bandinių fizikinės mechaninės charakteristikos, ištirta pluoštų sąlyčio zona su AAC matrica, nustatyta drėgnio įtaka AAC savybėms ir šalčio atsparumas. Disertacijoje pateikta patobulinta AAC gamybos technologinė schema. / Dissertation analizes the influence of fiberous additives on the properties of autoclaved aerated concrete (AAC). The corrosion of fibers in alkaline medium and the resistance to hydrothermal exposure was investigate, the optimal composition of formation admixtures and its parameters of mixing was selected, optimal quantities and parameters of fibrous admixture was determined, the effect of surface active agents (SAA) used for hydrophilization of fibers on hydration of Portland cement was investigate to. The effect of fibrous admixtures on properties of AAC products (density, macro- and microstructure, reinforcing fibrous admixture – AAC matrix contact zone, compression strength, bending strength, freeze resistance) was determined. A new modernized technological scheme of AAC producing is presented in this dissertation.
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Elaboration et caractérisation de nanoparticules luminescentes par upconversion pour l'imagerie médicale / Elaboration and characterization of upconverting luminescent nanoparticles for medical imagingFrancolon, Nadège 11 December 2015 (has links)
L’objectif de ces travaux de thèse repose sur la conception de nanoparticules pour l’upconversion (UCNPs) visant à réaliser de l’imagerie médicale par fluorescence. L’intérêt de ces nano-objets s’appuie sur l’excitation et l’émission conjointe dans le domaine du proche infrarouge, permettant de travailler dans la fenêtre thérapeutique des tissus. Une première partie présente l’élaboration des nanoparticules sphériques de NaYF 4 , dont le taux de dopage a permis de mettre en avant les conversions possibles grâce aux phénomènes optiques d’upconversion (IR → NIR, IR → visible et IR → UV). De plus, l’étude d’hydrophilisation, primordiale pour des applications médicales, a montré un fort intérêt pour l’enrobage par échange de ligands et plus particulièrement par des molécules dendritiques. Dès lors que les nano-objets ont été validés et stabilisés dans un milieu aqueux, ces derniers ont été testés in vitro et ont permis de montrer une cytotoxicité faible. La dernière partie a permis d’adapter l’équipement IVIS SPECTRUM® à nos conditions optimales d’utilisation des UCNPs. Cette installation a validé la preuve de concept de nos UCNPs in vivo, permettant ainsi d’être imagées chez le petit animal. Ce dispositif, encore unique en Europe ouvre ainsi la voie pour des études plus approfondies de l’utilisation des UCNPs pour la détection de tissus spécifiques, tels que les tissus tumoraux. / The aim of this PhD work deals with the design of upconverting nanoparticles (UCNPs) to perform medical imaging by fluorescence. The interest of these nano-objects is based on both excitation andemission in the near infrared range, allowing the work in the therapeutic window of tissue. The first part presents the development of spherical nanoparticles of NaYF 4 , which the doping concentration has highlighted the transitions permits through upconversion phenomena (IR → NIR, IR → visible and IR → UV). In addition, the hydrophilization part, necessary for medical application, has shown a strong interest in the coating by ligand exchange and particularly by dendritic molecules. Since the nanoparticles have been validated and stabilized in aqueous medium, they were tested in vitro and have shown low cytotoxicity. The last part was to adapt the IVIS SPECTRUM® equipment to our optimal conditions of use of UCNPs. This installation has validated the proof of concept of our UCNPs in vivo, which is to image in small animals. This device, also unique in Europe, opens the way for further use of UCNPs studies for the detection of specific tissues such as tumor tissues.
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Modifica??o superficial do tecido de malha de ?cido polilatico (PLA) por tratamento plasma / Surface modification of knitting poly lactic acid (PLA) by Plasma TreatmentCruz, Luciani Paola Rocha 08 August 2013 (has links)
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Previous issue date: 2013-08-08 / Some fibrous materials, for having properties such as biocompatibility, strength
and flexibility, are of great interest for medical and pharmaceutical applications.
Among these materials, the fabric made from polylactic acid (PLA) has received
special attention, and beside to present these features, is derived from
biological source, antimicrobial and bioabsorbable. One of the limitations of PLA
is its low wettability and capillarity. Due to this, it is necessary to perform
surface modification of the knitted fabric, increasing its hydrophilicity. This work
aims to realize the plasma treatment at low pressure in order to increase the
surface energy of the polymer. The work was divided into three steps: i)
Influence of the gas ratio (oxygen and nitrogen) in the surface modification of
PLA fabric after the plasma treatment, ii) physical characterization and
physicochemical surface tissue; iii) Evaluation of the effect from current and
gas ratio in the capillary rise of tissues and iv) Study of capillarity in yarns and
fabrics. The results showed that better gas ratios were the atmospheres: 100%
oxygen; 100% nitrogen and 50% oxygen and 50% nitrogen. The surface
characterization showed changes in topography and introduction of polar
groups which increased the wettability of the fabric. In another part of this study,
it was found that the atmosphere containing only nitrogen gas showed the most
capillary rise to a current of 0.15 A. The results in capillary yarns and fabrics
showed that the thread reached equilibrium in a time much less than the fabric
to an atmosphere of 100% nitrogen and 0.15 A. Current Plasma technology
was effective to increase the hydrophilicity of PLA fabric, providing surface
characteristics favorable for future application in the biomedical field / Alguns materiais fibrosos, por apresentarem propriedades como
biocompatibilidade, resist?ncia e flexibilidade, s?o de grande interesse para
aplica??es m?dicas e farmac?uticas. Dentre estes materiais, o tecido produzido
com ?cido poli l?ctico (PLA) tem recebido aten??o especial por, al?m de
apresentar estas caracter?sticas, ? derivado de fonte biol?gica e bioabsorv?vel.
Uma das limita??es do PLA ? sua baixa molhabilidade e capilaridade. Devido a
isto, torna-se necess?rio realizar modifica??o superficial do tecido de malha,
aumentando sua hidrofilicidade. O presente trabalho tem como objetivo realizar
o tratamento a plasma a baixa press?o com a finalidade de aumentar a energia
superficial do fio e da malha. O trabalho foi divido em tr?s etapas: i) Influ?ncia
da raz?o de g?s (oxig?nio e nitrog?nio) na modifica??o superficial do tecido de
PLA ap?s tratamento a plasma; ii) caracteriza??o f?sica e f?sico-qu?mica da
superf?cie do tecido; iii) avalia??o do efeito da corrente e raz?o de g?s na
ascens?o capilar de tecidos e iv) estudo da capilaridade em fios e tecidos. Os
resultados mostraram que as melhores raz?es de gases foram em atmosfera
100% oxig?nio, 100% nitrog?nio e 50% oxig?nio e 50% nitrog?nio utilizando
uma corrente de 0,15 A . A caracteriza??o superficial mostrou mudan?as na
topografia e introdu??o de grupos polares o que aumentou a molhabilidade do
tecido de malha. Em outra etapa desse estudo, constatou-se que a utiliza??o
atmosfera gasosa contendo apenas nitrog?nio foi a que apresentou a maior
ascens?o capilar para uma corrente de 0,15 A. Os resultados de capilaridade
em fios e tecidos mostraram que o fio atingiu o equil?brio em um tempo bem
menor que o tecido para uma atmosfera de 100% nitrog?nio e corrente de 0,15
A. A tecnologia de plasma mostrou-se eficaz para aumentar a hidrofilicidade do
tecido de malha de PLA, proporcionando caracter?sticas superficiais favor?veis
para futura aplica??o na ?rea biom?dica
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