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Goldmann applanation tonometry error relative to true intracameral intraocular pressure in vitro and in vivoMcCafferty, Sean, Levine, Jason, Schwiegerling, Jim, Enikov, Eniko T. 25 November 2017 (has links)
Background: Goldmann applanation tonometry (GAT) error relative to intracameral intraocular pressure (IOP) has not been examined comparatively in both human cadaver eyes and in live human eyes. Futhermore, correlations to biomechanical corneal properties and positional changes have not been examined directly to intracameral IOP and GAT IOP. Methods: Intracameral IOP was measured via pressure transducer on fifty-eight (58) eyes undergoing cataract surgery and the IOP was modulated manometrically on each patient alternately to 10, 20, and 40 mmHg. IOP was measured using a Perkins tonometer in the supine position on 58 eyes and upright on a subset of 8 eyes. Twenty one (21) fresh human cadaver globes were Intracamerally IOP adjusted and measured via pressure transducer. Intracameral IOP ranged between 5 and 60 mmHg. IOP was measured in the upright position with a Goldmann Applanation Tonometer (GAT) and supine position with a Perkins tonometer. Central corneal thickness (CCT) was also measured. Results: The Goldmann-type tonometer error measured on live human eyes was 5.2 +/- 1.6 mmHg lower than intracameral IOP in the upright position and 7.9 +/- 2.3 mmHg lower in the supine position (p <.05). CCT also indicated a sloped correlation to error (correlation coeff. = 0.18). Cadaver eye IOP measurements were 3.1+/-2. 5 mmHg lower than intracameral IOP in the upright position and 5.4+/- 3.1 mmHg in the supine position (p <.05). Conclusion: Goldmann IOP measures significantly lower than true intracameral IOP by approximately 3 mmHg in vitro and 5 mmHg in vivo. The Goldmann IOP error is increased an additional 2.8 mmHg lower in the supine position. CCT appears to significantly affect the error by up to 4 mmHg over the sample size.
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Experimental Study on the Engineering Properties of GelfillAbdul-Hussain, Najlaa January 2011 (has links)
Gelfill (GF) is made of tailings, water, binder and chemical additives (Fillset, sodium silicate gel). The components of GF are combined and mixed on the surface and transported (by gravity and/or pumping) to the underground mine workings, where the GF can be used for both underground mine support and tailings storage.
Thermal (T), hydraulic (H), and mechanical (M) properties are important performance criteria of GF. The understanding of these engineering properties and their evolution with time are still limited due to the fact that GF is a new cemented backfill material.
In this thesis, the evolution of the thermal, hydraulic, mechanical, and microstructural properties of small GF samples are determined. Various binder contents of Portland cement type I (PCI) are used. The GF is cured for 3, 7, 28, 90, and 120 days. It is found that the thermal, hydraulic and mechanical properties are time-dependent or affected by the degree of binder hydration index. Furthermore, a relationship is found between the compressive strength and the saturated hydraulic conductivity of the GF samples.
The unsaturated hydraulic properties of GF samples have also been investigated. The outcomes show that unsaturated hydraulic conductivity is influenced by the degree of binder hydration index and binder content, especially at low suction ranges. Simple functions are proposed to predict the evolution of air-entry values (AEVs), residual water content, and fitting parameters from the van Genuchten model with the degree of hydration index (α). Furthermore, two columns are built to simulate the coupled thermo-hydro-mechanical (THM) behaviour of GF under drained and undrained conditions. The obtained results from the GF columns are compared with the small samples. It is observed that the mechanical properties, hydraulic properties (suction and water content), and temperature development are strongly coupled. The magnitude of these THM coupling factors is affected by the size of the GF. The findings also show that the mechanical, hydraulic and thermal properties of the GF columns are different from samples cured in plastic moulds.
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Altération aqueuse et hydratation en phase vapeur du verre SON68 à basse température (35-90°C) / Aqueous and water vapour alteration of the SON68 glass at low temperature (35-90°C)Bouakkaz, Rachid 24 September 2014 (has links)
Le verre SON68 est dans un premier temps altéré en mode dynamique dans l’eau de COx riche en silicium (42mg/L) à pH 8, à fort S/V (14000 m⁻¹) et à 35, 50 et 90°C. Les résultats montrent que l’altération du verre semble être gouvernée par un mélange de processus de diffusion et de réaction de surface. La vitesse résiduelle à 90°C est de l’ordre de 10⁻⁴ g.m⁻².j⁻¹, l’énergie d’activation est de l’ordre de 70 kJ.mol⁻¹. Un mécanisme de dissolution/précipitation et d’hydrolyse/condensation sont responsables du développement de la couche d’altération. Les silicates de Mg et la calcite précipitent à 35 et 50°C, mais en plus la powellite et l’apatite ont été identifiées à90°C. Les résultats de la modélisation géochimique reproduisent les données expérimentales. Le verre est ensuite hydraté à des températures allant de 35 à 125°C et des valeurs d’humidité relative (HR) entre 92 et 99,9%. L’hydratation du verre augmente avec la température et l’HR. L’énergie d’hydratation est de l’ordre de 34,2 kJ.mol⁻¹. Les épaisseurs des couches d’altération varient entre 0,3μm à 35°C et 5μm à 125°C. La couche d’altération est appauvrie en (B, Li, Na) et enrichie en (Si, Al, Fe, Ca, Zn et Ni). Les principales phases secondaires formées sont la calcite, la powellite, l’apatite, la tobermorite et un gel hydraté.L’influence des matériaux en champ proche sur l’altération du verre SON68 dopé en ²⁹Si a été étudiée. La présence d’acier augmente le pH et diminue la concentration en Si et en Mo sans modifier la vitesse globale de corrosion du verre. Le Si est retenu sur les produits de corrosion d’acier, sa concentration en solution semble être contrôlée par la dissolution de l’argilite. La corrosion du verre en présence d’acier et d’argile à 90°C conduit à la formation de magnétite, sidérite, ferrosilicates, silice pure, sulfures de fer (pyrite, troïlite, pyrrhotite etmackinawite), calcite, apatite, powellite et silicates de Mg. Les résultats de modélisation sont en bon accord avec les données expérimentales. / The SON68 glass is initially altered in dynamic mode under silica rich COx water (42 mg/L) at pH8, high S/V ratio (14000 m⁻¹) and at 35, 50 and 90°C. The results showed that the glass alteration seems to be governed by both diffusion and surface reaction process. The residual rate at 90°C is around 10-4 g.m⁻².d⁻¹. The activation energy is about 70 kJ.mol⁻¹. The dissolution /precipitation and hydrolysis/condensation mechanisms are responsible for the development of the alteration layer. Mg silicates and calcites precipitate at 35 and 50°C, the same phases in addition to powellite and apatite precipitate at 90°C. The results predicted by the model reproduce well experimental data. The glass is then hydrated at temperatures ranging from 35 to 125°C and relative humidity values (RH) between 92 an 99.9%. The glass hydration increases with the temperature and RH, the hydration energy is about 34.2 kJ.mol⁻¹. The alteration layers thicknesses vary between 0.3μm at 35°C and 5μm at 125°C. The alteration layer is depleted in (B, Li, Na) and enriched in (Si, Al, Fe, Zn and Ni). The secondary phases are calcite, powellite, apatite and tobermorite in adition to a hydration gel. The effect of near field materials on the ²⁹Si doped SON68 glass alteration was studied. The presence of steel increases the pH and decreases the Si and Mo concentrations without changing the overall rate of glass corrosion. The Si is retained on the steel corrosion products, its concentration in solution seems to be controlled by the clay dissolution. The glass corrosion in the presence of steel and clay at 90°C leads to the formation of magnetite, siderite, ironsilicates, pure silica, iron sulphur (pyrite, troilite,pyrrhotite and mackinawite), calcite, apatite, powellite and Mg silicates. The modelling results agree well with the experimental data.
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Desenvolvimento de formulação cosmética contendo carreadores lipídicos nanoestruturados à base de manteiga de Ourateasp. : uma estratégia nanotecnológica para o aumento da hidratação cutâneaGalvão, Juliana Gouveia 20 February 2015 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Nanostructured lipid carriers (NLCs) have been developed in order to improve cutaneous hydration. Due to its ultrafine particle size it is possible a film formation on the skin which decreases transepidermal water loss, improving occlusive effect and hydration. In this context, the aim of this work was to develop a formulation containing NLCs based in Ouratea sp. butter (Ochnaceae) as a strategy to increase cutaneous hydration. Firstly, it was performed a characterization of the components such as, stearic acid (SA), Ouratea sp. butter (OB), Phospholipon 90G®, and its physical mixtures by Differential Scanning Calorimetry (DSC), Thermogravimetry
(TG) and X ray Diffraction (XRD). The NLCs were prepared using the diffusion solvent method and evaluated for particle size, polidispersity index, zeta potential, pH and conductivity. Moreover, NLCs were characterized by DSC, XRD and
Transmission electron microscopy (TEM). Finally, the NLCs were incorporated into a cream base and were evaluated for rheological behavior, occlusive effect and potential cutaneous hydration in vitro. From the raw materials characterization was
possible to observe in which the PM1 (SA + OB) 1:1 showed a slightly shift of the melting point corresponding to SA (57 to 50°C) and presented an amorphous portion
at ~ 20° in the XRD analysis. These observations could be attributed to a decrease of crystallinity when compared with solid lipid pure, highly ordered. With the addition of
Phospholipon® 90G (PM2), the melting point was highly shifted to lower temperature (57 to 34°C), and presented a pronounced amorphous at ~ 20° in XRD. Since the NLCs need to remain solid at room and body temperature, it is suggested that using
a lower proportion of the Phospholipon® 90G in NLCs formulations. From the CMC determination of SDS surfactant (8,02 mmol L-1) was possible to suggest a range
concentration of the SDS in the NLCs preparations. The formulation with the highest SDS concentration (24 mmol L-1) demonstrated the lowest size particle (~ 240 nm),
however there were no difference in the zeta potential over formulation that using 10 mmol L-1 of SDS (~ -50 mV). The NLCs presented a decrease in the enthalpy (ΔHNLC8 = 22.2, ΔHNLC10 = 23.2, ΔHNLC24 = 7.2 J/g) and also an increase in the width peak when compared with solid lipid SA pure (ΔHSA = 164.1). In addition, the XRD analysis demonstrated that NLCs presented main peaks both formulations are similar
to those found in the SA (23.93°, 25.09°, 27.98°), but with a lower intensity. These observations suggest a lipid matrix less ordered which result in NLC formation. TEM results confirmed previous data related to NLCs particle size (200 to 300 nm). After the incorporation of the NLC10 into a cream base, it was possible to observe an increase in the occlusive effect and potential cutaneous hydration. Therefore, NLCs containing Ouratea sp. butter can be an attractive nanotechnology way to increase cutaneous hydration. / Carreadores Lipídicos nanoestruturados (CLNs) têm sido desenvolvidos visando uma melhor hidratação cutânea. Devido ao seu reduzido tamanho de partícula, há formação de um filme sobre a pele o qual diminui a perda de água transepidermal,
aumentando a hidratação. Neste contexto o objetivo deste trabalho foi desenvolver uma formulação contendo CLNs à base de manteiga de Ouratea sp. (Ochnaceae) como uma estratégia para o aumento do efeito oclusivo e da hidratação cutânea.
Primeiramente foi realizada a caracterização das matérias-primas como, ácido esteárico (AE), Manteiga Ouratea sp.(MO), Phospholipon 90G® e suas misturas físicas utilizando Calorimetria Exploratória Diferencial (DSC), Termogravimetria (TG)
e Difração de raios-X (DRX). Os CLNs foram preparados pelo método de difusão do solvente e avaliados por diâmetro médio de partícula, índice de polidispersão, potencial zeta, pH e condutividade. Os CLNs ainda foram caracterizados por DSC e
DRX, Microscopia eletrônica de Transmissão (MET). Por fim, os CLNs foram incorporados no creme base e foram avaliados quanto ao comportamento reológico, efeito oclusivo e potencial hidratação cutânea in vitro. Através da caracterização das
matérias-primas foi possível observar que a MF1 (AE + MO) 1:1 mostrou um pequeno deslocamento do ponto de fusão correspondente ao AE (57 a 50°C) e apresentou uma porção amorfa em ~ 20° nas análises de DRX. Essas observações
podem ser atribuídas à diminuição da cristalinidade quando comparado com o lipídeo sólido puro, altamente ordenado. Com a adição do Phospholipon 90G® (MF2), o ponto de fusão foi deslocado para uma temperatura menor (57 a 34°C), e
apresentou uma pronunciada porção amorfa em ~ 20° no DRX. Partindo do pressuposto que os CLNs devem se manter sólidos a temperatura ambiente e corpórea, é sugerida a utilização de uma menor proporção de Phospholipon® 90G
nas formulações de CLNs. A partir da determinação da CMC do tensoativo SDS (8,02 mmol L-1) foi possível sugerir uma faixa de concentração de SDS nas preparações de CLNs. A formulação com a maior concentração de SDS (24 mmol L-
1) demonstrou o menor diâmetro de partícula (~ 240 nm), entretanto, não houve diferenças no potencial zeta em relação a formulação em que foi utilizado 10 mmol L-1 of SDS (~ -50 mV). CLNs apresentaram uma diminuição nos valores de
entalpia (ΔHCLN8 = 22,2; ΔHCLN10 = 23,2; ΔHCLN24 = 7,2 J/g) e também um aumento da largura do pico quando comparados com o AE puro (ΔHSA = 164,1). Além disso, as
análises de DRX demonstraram que os CLNs apresentaram picos principais similares àqueles encontrados no AE (23,93°; 25,09°; 27,98°), porém com uma menor intensidade. Os resultados de MET confirmaram os dados de diâmetro médio
de partícula dos CLNs (200 a 300 nm). Após a incorporação do CLN10 no creme base, foi possível observar um aumento no efeito oclusivo e na hidratação cutânea. Dessa forma os CLNs contendo manteiga de Ouratea sp. podem ser uma alternativa
nanotecnológica atrativa para o aumento da hidratação cutânea.
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Impact of curing methods on the strength of copper slag concreteKyalika, Cynthia Mumeka 10 1900 (has links)
The eco-friendly alternatives use is increasing momentum in a conscious effort
towards sustainability. In this regards, the relevance and the economic value of
using copper slag as a concrete aggregate are explored in this study in order to
contribute towards metallurgical waste recycling. Emphasis is placed on the
evaluation of the concretes strengthening prepared with copper slag contents and
produced under four curing methods: water immersion, water spraying, plastic
sheet covering and air-drying. In each curing case excluding for water immersion,
was duplicated in indoors (i.e. in the laboratory) and outdoor exposure (so was
prone to varying environmental conditions). This was specifically aimed at
capturing the effects of tropical weather conditions typical of the Lualaba province
in the Democratic Republic of Congo.
The control mix was designed to reach 25 MPa of compressive strength. Copper
slag was successively incorporated as sand replacement at the following mass
fractions: 20 %, 40 % and 60 %. Freshly mixed concrete samples were evaluated
for workability. Cube specimens were cast accordingly, cured for 28 days and then
tested for density and compressive strength.
Results indicated an increase in strength up to 20 % of replacement rate for all the
curing methods. Further additions resulted in reduction in the strength, but the rate
of reduction depended on curing conditions. The increase in strength was mainly
credited to the physical properties of copper slag that could have contributed to the
cohesion of the concrete matrix. It has been found that appropriate ways of curing
can still achieve greater results than that of the control mix since 80 % of humidity
is ensure. The two-way ANOVA test performed on the 28-days compressive
strength values confirmed the significant influence of the curing methods, of copper
slag content and the interaction between them. It has been found that considerable
influence is attributed to copper slag content and that warm environmental
conditions further extend the concrete strengthening. / College of Engineering, Science and Technology / M. Tech. (Chemical Engineering)
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Časový vývoj reologických parametrů strusky aktivované různými aktivátory / Time evolution of rheological parameters of slag activated with various activatorsPazour, Miroslav January 2021 (has links)
Tato diplomová práce se zabývá aktuálními poznatky, společně s optimalizací oscilačních měření pomocí hybridního reometru, ale hlavně pozorováním změn reologických parametrů v čase past mleté granulované vysokopecní strusky aktivované různými aktivačními roztoky s koncentrací alkálií M: 4 and 7.5 moldm. Výsledky byly pro diskuzi podpořeny výstupy z Vicatovy metody a izotermické kalorimetrie. Nejprve bylo zjištěno, že limit lineární viskoelastické oblasti se zmenšuje v čase. Dále bylo pozorováno, že v time sweep testech vykazovala struska aktivovaná křemičitany nejnižší hodnoty komplexního modulu a struska aktivovaná hydroxidy o koncentraci 4 moldm nejvyšší hodnoty a ostatní pasty vykazovaly hodnoty mezi těmito dvěma extrémy a měly mezi sebou porovnatelné hodnoty. Podobný trend byl pozorován u vývoje kritické meze oscilačního napětí, získaného z amplitude sweep testů (přerušovaně a nepřerušovaně). Oba výše zmíněné parametry, komplexní modul a mez napětí, se vyvíjely v čase. Výsledky všech testů jasně ukázaly, že povrchová chemie hraje roli ve výsledném reologickém chování. Odsud, povaha a koncentrace aktivátoru ovlivňují reologické vlastnosti skrze efekty Na a K iontů, stejně tak skrze koncentraci, která má dopad na elektickou dvojnou vrstvu. Reologické chování může být také ovlivněno dalšími faktory, např. viskozitou aktivačního roztoku a celkovou kinetikou hydratačního procesu.
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Studium průběhu zrání a vysychání objemově kompenzovaných potěrových hmot / Study of maturing process of volume stabilised floor flow screedsKonvičný, Václav January 2020 (has links)
The diploma thesis is devoted to the comparison of drying processes of various types of poured floor self-levelling screeds under conditions close to construction practice, especially during maturation under different climatic conditions. These properties were observed by several methods. The course of strength increases and final strength of tested materials under different climatic conditions were also found and compared. The conclusion summarizes the knowledge about the course of drying and the course of development of strengthening of individual floor materials.
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Analýza objemových změn cementových kompozitů s ohledem na optimalizaci dávkování jemných složek / Analysis of volume changes of cement composites with respect to optimizing the dosage of fine componentsMeruňka, Milan January 2020 (has links)
The diploma thesis deals with the determination of the influence of the maximum density of the cement matrix on the volume changes of concrete, the influence of different admixtures or their combinations on the development of hydration temperatures and on the water separation of concrete. The theoretical part describes the various types of volume changes of concrete, the effects of individual input components and mineral admixtures on water separation, hydration heat development and concrete microstructure. The experimental part is focused on monitoring not only the volume changes of concrete mixtures made using different types of admixtures or their suitable combination until the age of 60 days of maturation, but also the influence of their use on selected mechanical parameters of concrete such as compressive strength, concrete in its fresh state and monitoring changes in the microstructure from long-term aging mixtures.
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Nejnovější účinné látky přírodního původu pro anti-aging kosmetiku / Anti-aging cosmetics - latest activ substances of natural originFleková, Andrea January 2014 (has links)
The present diploma thesis is focused on the selected anti-aging substances in cosmetic products. The literature research provided us with the knowledge of essential skin characteristics and factors influencing the aging process. Furthermore, the thesis describes the basic physical forms of cosmetic products, the basic cosmetic materials and the current trends in the usage of anti-aging substances. The experimental part subsumes altogether four physical forms of cosmetic products – tonics, serums, masks and creams. In this work was testid a new anti-aging compound, developer by French company SOLABIA, which provided the company Miša a Harašta s.r.o. (M+H). It has tested four components: Fucogel, Camaderm Gly, Viniderm and Omega Ceramid. These anti-aging substances were addend to the four technology cosmetic form, which were prepared in our laboratory. Subsequently, the pH stability of the products was measured together with the rheological measuring and skin hydration measuring. All of the samples proved to be pH stable. The highest stability of viscosity and consistence was identified for masks and creams. It was found out that the added anti-aging substances have no impact on the stability of pH, viscosity and consistency. The skin hydration measuring proved that the anti-aging substances Vinidem and Camadem Gly have the greatest moisturising qualities.
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Vliv přísad redukujících smrštění na reologické vlastnosti vysokopevnostního betonu / The effect of the shrinkage reducing additives on rheological properties of high-strength concreteČervenka, Jiří January 2013 (has links)
Master’s thesis examines the effect of the shrinkage reducing additives on rheological properties of high-strength concrete. The first part is focused on high-strength concrete in terms of their composition and properties. The second part contains a detailed analysis of the cementitious composites shrinkage problems. Total shrinkage is divided into individual elementary shrinkages. For each of them there is a detailed description of causes and factors that affect their sizes. The next part describes the basic additives used to reduce the shrinkage of cementitious composites. The experimental part is focused on verifying the effectiveness of the shrinkage reducing additives during preparation of high-strength concrete. Usage of shrinkage drains for relative strain measurement enables to determine the process of shrinkage immediately after placing the concrete in the form and to obtain the overall curve of the hight-strength concrete volume changes during its setting and hardening. At the end of the thesis, there are overall analysis and summary of the results of the performed experiments.
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