The permeability in siliclastic rocks can vary due to different pore geometries. The pore properties of a formation can also have significant effects on reflection coefficient. The pore structure of clastic rock may be predicted from a wave reflection using mathematical models. Biot-Gassmann and Sun’s equations are examples of two models which were used in this research to quantify the pore property. The purpose of this thesis is to measure variations in porosity and permeability using 3-D time lapsed seismic during a CO_(2) flood. CO_(2) sequestration EOR will most likely cause permanent diagenetic effects that will alter pore geometry and permeability. This research shows compelling evidence that the pore structure changes in an active CO_(2) flood at the Delhi Holt-Bryant reservoir can be measured with acoustic data. The pore property change is measured by using the Baechle ratio, the Gassmann model, and the Sun framework flexibility factor. The change in the pore properties of the formation also indicates a increase in the permeability of the reservoir as a result of CO_(2) interaction.

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Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal

Modeling of airflow resistance in grain bulk requires knowledge of the tortuosity and velocity of the air flow through the grain bulk. In this study, experiments were carried out to determine these characteristics of airflow paths by analyzing digital images of smoke-visualized airflow paths inside a grain bulk obtained with a high speed camera. Colored smoke with approximately the same density as air was introduced into the test box for the visualization of the airflow through the grain bulk. Soybeans with a moisture content of 8.82% on wet basis were used in this study. The high quality videos obtained by recoding the fast movement of the smoke through the grain bulk was first separated into frames using a commercial software, VirtualDub (CRIM, Montreal, Québec, Canada), and the 512× 384 pixel RGB image files (frames) extracted from the recorded videos and read into ImageJ an image processing Java-based software developed by the United State National institute of Health, to track the movement of the smoke in the images, frame by frame to determine lengths, tortuosities of the different flow paths, as well as their velocities.

In the past decade, the grouting industry has made significant technological advancements in real-time monitoring of flow rate and pressure of pumped grout, stable grout mix design, and with grout curtain concepts dealing with placement and orientation. While these practices have resulted in improved construction practices in the grouting industry, current design guidelines for grout curtains are still predominately based on qualitative measures such as engineering judgment and experience or are based on proprietary methods. This research focused on the development of quantitative guidelines to evaluate the effectiveness of a grout curtain in porous media using piezometric and hydraulic flow data. In this study, a laboratory-scale physical seepage model was developed to aid in the understanding and development methodology to evaluate the effectiveness of a grout curtain. A new performance parameter was developed based on a normalization scheme that utilized the area of the grout curtain and the area of the improved media. The normalization scheme combined with model-based Lugeon values that correspond to pore pressure and flow rate measurements at different soil unit weights and grout curtain spacings, produced a mathematical equation that can be used to quantify the effectiveness of a grout curtain. This study found a relationship that takes into account soil unit weight, grout curtain spacing and a new performance parameter that can be used to help predict the effectiveness of a grout curtain.

Prairie Creek Reservoir in east central Indiana serves as a secondary water supply for the city of Muncie and is also used as a recreational facility. Due to water quality concerns, this study was conducted to characterize spatial and temporal variability of physical and chemical parameters, specifically nutrients, in the sediment interstitial (pore) water at three reservoir locations. The pH, temperature, specific conductivity, ammonia, nitrates, total nitrogen, orthophosphates and total phosphorus, were monitored twice per month from June through September 2006. Spatial variations in the sediment interstitial water were evident for all water quality parameters, except phosphorus and orthophosphates. Variability in temporal nutrient concentrations in pore water was most likely affected by decomposition of organic matter and presence of anoxic conditions in the overlying water. The results showed high internal nutrient loading, especially from phosphorus, in the sediment interstitial water. Under anoxic conditions, these excessive nutrient concentrations within the sediment can be released into the water column and exacerbate eutrophication of the reservoir. This study provides useful assessment of internal nutrient loading in the Prairie Creek Reservoir sediment that should be considered in the implementation of land management strategies and future land development practices in the reservoir watershed. / Department of Natural Resources and Environmental Management

In this project the relation between pore size/porosity and the mechanical properties has been studied in the aerogel-like material Quartzene®. Quartzene® is a patented material produced by Svenska Aerogel AB. Density measurements were made on three different types of Svenska Aerogels ABs Quartzene® in the shape of pellets.These three types of Quartzene® is called CMS, ND and E9. The mechanical properties were studied by doing diametrical crush-tests on the pellets. Afterwards the samples were examined through SEM in order to study the structural properties like porosity and microstructure. By examining the materials in this order the group hoped to find a correlation between the mechanical properties and the pore size/porosity. Other microscopic analyses such as TEM and FIB was considered, but due to time limitation these methods were not used. Rough density measurements resulted in an estimated density of 0.82-0.88 g/cm3 for CMS, 0.28-0.30 g/cm3 for E9 and 0.21-0.22 g/cm3 for ND. The crush-tests resulted in a mean fracture stress of 0.81-0.89 MPa for CMS, 0.30 MPa for E9 and 0.20-0.21 MPa for ND. Studying the materials in SEM resulted in an observed mean pore size of 59-73 nm for CMS, 264-362 nm for E9 and 690-710 nm for ND in the mesoporous domain. A subtle relationship between density/pore size and fracture was obtained, with a higher density and smaller pores leading to a higher fracture stress. Due to the lack of data in this study, it is recommended though that this is something that should be examined further before any conclusions can be made. In general Quartzene® has shown to be a brittle material, but this study indicates that the mechanical properties could be controlled in somehow through the microstructure of the material, focusing on controlling the pore sizes. Further investigations in sintering of Quartzene® are also recommended in this study because of its promising effects on the mechanical properties shown in other studies.

Lime mortar and plaster have been investigated with the aim to improve the knowledge on how to make them as durable as before the cement technology was developed. The background was the durability problems experienced for newly produced lime plaster on the medieval churches on the island of Gotland, Sweden. In some cases the new lime plaster façades showed severe frost damages after only one winter. Although the lime was burnt and produced according to old local traditions, the lime mortar was still mixed and worked onaccording to methods developed for lime-cement mortar. This often led to a very porous lime plaster with a lime shell in the surface and such a plaster has been shown to be sensitive to frost expansion. Field studies were combined with laboratory studies of thin section specimens. Optical microscopy and scanning electron microscopy have been important analytical methods showing the porosity and the structure of the binder and aggregate materials. The investigations have been carried out on both historic and on newly made reference mortar and plaster. The field studies were carried out mainly on Gotland, using local materials. The influence of the raw materials, i.e. lime, aggregate and blending ratio was investigated. The focus has been on the workability of the fresh mortars as well as the pore structure of the carbonated plaster. The craftsmanship, meaning mixing and application of mortar and working the plaster surface, was studied in order to clarify its final pore structure. The pore structure in a material determines many of its technical properties, such as moisture transportation, compressive strength, permeability and frost resistance. All these properties are closely connected to the durability of the mortar and plaster. The permeability of the plaster has an impact also on the durability of the covered construction materials. Behind low-permeable plasters made with hydraulic binder, examples of extensive damages of rotten wood and leached lime have been shown. The investigations have shown the importance of choosing a mortar adjusted to the building construction. They also showed the importance of choosing a blending ratio adjusted to the specific binder and sand used in order to get a mortar with a suitable pore structure and good durability. It has also shown the importance of knowing when and how to work on the plaster surface in order to obtain a homogenous material that is well receptive for lime wash and has a good frost resistance. The combination of all the investigations has led to a method for reconstructing historic mortar and plaster with good durability.

Zeolite membranes are considered to be a promising alternative to polymeric membranes and they have the potential to separate gases under harsh conditions. Silicalite-1 membranes in particular are easy to prepare and suitable for several industrial applications. In this research project, silicalite-1/ceramic composite membranes were prepared using the pore plugging hydrothermal synthesis method and supports with zirconium oxide and/or titanium oxide as active layers. The effect of the support’s pore size on the morphology and permeation performance of the prepared membranes was investigated using five supports with different active layer pore sizes in the range of 0.14 – 1.4 m. The prepared membranes were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), electron diffraction spectrometer (EDS), single gas and binary gas mixtures permeation tests. The results confirmed the presence of a typical silicalite-1 zeolite structure with a high internal crystalline order grown inside the pores of the active layer of the supports, with a dense film covering most of the supports active layers. Silicalite-1 crystals in the prepared membranes were preferably oriented with either a- or b-axes perpendicular to the support surface. Single gas permeation results illustrated that the observed permeances were not directly related to the kinetic diameter of permeants. Instead, the transport of the studied gases through the prepared membranes occurred by adsorption followed by surface diffusion mechanism. Binary gas tests performed with CO2 and N2 mixtures showed that the prepared membranes were selective and very permeable with CO2/N2 permselectivities up to 30 and a CO2 permeances in the order of 10-6 mol m-2 Pa-1 s-1. A model was developed, based on Maxwell−Stefan equations and Extended Langmuir adsorption isotherm, to describe the transport of binary CO2 and N2 mixtures through the prepared silicalite-1 membranes. The model results showed that the exchange diffusivities (D12 and D21) were less dependent on the feed pressure and feed composition compared to the permeances and the permselectivities. Hence, they are more appropriate to characterize the intrinsic transport properties of the prepared silicalite-1 membranes.

The work described by this thesis is a comparison of pore opening geometry for true surface microfilters. True surface microfilters can be thought of as very fine sieves, with pore sizes less than 10 microns. All other types of so-called microfiltration membranes do not rely on sieving, but obtain their pore retention rating by particle collection mechanisms similar to depth filters. Particle deposition within such microfilters results in permeate flow rate dechne, for a fixed pressure filtration, or pressure drop rise, for a fixed rate filtration. The true surface microfilter pore geometnes considered were circular and slotted, and microfilters with filtering dimension of less than 10 microns were used. The slotted pore microfilters are not commercially available and had to be made in the laboratory as part of this study. The technique used was to plate nickel onto an existing substrate, thereby reducing the pore dimension until It was within the microfiltration range. The plating was by electroless nickel solution and not by galvanic means. Significant development of the electroless platmg technique led ultimately to the successful manufacture of process scale slotted surface microfilters.