Yes / When ocean waves propagate over porous seabed, they cause variations of the pore pressure within seabed, leading to the possible wave attenuation and soil liquefaction. In order to advance and improve our understanding of the process of wave-induced seabed liquefaction and its impact on wave propagation, systematical experiments are carried out in a wave flume with a soil basin filled with silt. Both the pore pressures and water surface elevations are measured simultaneously, while the seabed liquefaction is videotaped using a high-speed camera. Laboratory measurements show that the pore pressure in surface layer mainly oscillates over time, while the wave period averaged pore pressure has little change. In the deep layer, however, the wave period averaged value of the pore pressure builds up dramatically. The results show that the wave height decreases rapidly along the direction of wave propagation when seabed liquefaction occurs. Such a wave attenuation is greatly enhanced when the liquefaction depth further increases. The experiments also demonstrate that the conditions (wave height and wave period) of incident waves have significant impacts on the wave-induced pore pressures, liquefaction depth and wave attenuation in a silt bed. / National Natural Science Foundation of China (Grant No. 51479053), the 111 Project (Grant No. B12032), the marine renewable energy research project of State Oceanic Administration (GHME2015GC01), the Fundamental Research Funds for the Central University, China (Grant No. 2013B31614), the Colleges and Universities in Jiangsu Province Plans to Graduate Research and Innovation (Grant No. B1504708), and Open Foundation of State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University (Grant No: 2016491011).

Petrophysical properties are fundamental to understanding fluid flow processes in hydrocarbon reservoirs. Special Core Analysis (SCAL) routinely used in industry are time-consuming, expensive, and often destructive. Alternatively, easily available thin section data is lacking the representation of pore space in 3D, which is a requisite for generating pore network models (PNM) and computing petrophysical properties. In this study, these challenges were addressed using a numerical SCAL workflow that employs pore volume reconstruction from thin section images obtained from confocal laser scanning microscopy (CLSM). A key objective is to investigate methods capable of 2D to 3D reconstruction, to obtain PNM used for the estimation of transport properties. Representative thin sections from a well-known Middle-Eastern carbonate formation were used to obtain CLSM images. The thin-sections were specially prepared by spiking the resin with UV dye, enabling high-resolution imaging. The grayscale images obtained from CLSM were preprocessed and segmented into binary images. Generative Adversarial Networks (GAN) and Two-Point Statistics (TPS) were applied, and PNM were extracted from these binary datasets. Porosity, Permeability, and Mercury Injection Porosimetry (MIP) on the corresponding core plugs were conducted and an assessment of the properties computed from the PNM obtained from the reconstructed 3D pore volume is presented. Moreover, the results from the artificial pore networks were corroborated using 3D confocal images of etched pore casts (PCE). The results showed that based on visual inspection only, GAN outperformed TPS in mimicking the 3D distribution of pore scale heterogeneity, additionally, GAN and PCE outperformed the results of MIP obtained by TPS on the Skeletal-Oolitic facies, without providing a major improvement on more heterogeneous samples. All methods captured successfully the porosity while absolute permeability was not captured. Formation resistivity factor and thermal conductivity showcased their strong correlation with porosity. The study thus provides valuable insights into the application of 2D to 3D reconstruction to obtain pore network models of heterogeneous carbonate rocks for petrophysical characterization for quick decision. The study addresses the following important questions: 1) how legacy thin sections can be leveraged to petrophysically characterize reservoir rocks 2) how reliable are 2D to 3D reconstruction methods when predicting petrophysical properties of carbonates.

<p> An age of approximately 55K years was found for the St. Clair basin clays using helium isotope dating. This is about 5 times larger than the date obtained from the more accepted carbon-14 method and from other geological evidence. Diffusion of helium from crustal rocks against a flow of approximately 0.03-0.05 cm a· ' is the primary reason for this discrepancy. Mixing of the groundwater with a meteoric component has an opposite effect tending to lower the helium age. </p> / Thesis / Bachelor of Science (BSc)

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Diffusion is an omnipresent, most fundamental phenomenon in nature and thus critical for the performance of numerous technologies. This is in particular true for nanoporous materials with manifold applications for matter upgrading by separation, purification and conversion. The path lengths of molecular transportation within the industrial plants range from the elementary steps of diffusion within the micropores of the individual particles up to the matter flow over macroscopic distances. Each of them might be decisive in determining overall performance so that detailed knowledge of all modes of mass transfer is crucial for a knowledge-based optimization of the devices with reference to their transport properties. The rate of mass transfer is particularly complicated to be assessed within the individual (adsorbent) particles/crystallites with pore sizes of the order of molecular dimensions. We are going to present two powerful techniques exactly for this application, operating under both equilibrium (Pulsed Field Gradient (PFG) NMR) and non-equilibrium (Microimaging by interference microscopy and IR microscopy) conditions. The potentials of these techniques are demonstrated in a few showcases, notably including the options of transport enhancement in pore hierarchies. The contribution concludes with a survey on present activities within an IUPAC initiative aiming at the elaboration of “guidelines for measurements and reporting of diffusion properties of chemical compounds in nanoporous materials”.

Cytolysin A (ClyA) is a member of a class of proteins called pore-forming toxins (PFTs). ClyA is secreted by Gram-negative bacteria, and it attacks a number of mammalian cells by inserting into and forming channels within the cell membrane (Oscarsson J et al., 1999). It has been suggested that ClyA binds to cholesterol (Oscarsson J et al., 1999) and thus can insert into the membranes of many different cell types of eukaryotic origin. In our studies we propose to engineer a ClyA protein that can only attack a small subset of cell types. We propose to engineer ClyA that can be only activated when exposed to specific cell-surface proteases produced by a specific cell type. We ultimately want to target breast cancer cells that differentially secrete or express proteases such as matrix-metalloproteases (Stautz D et al., 2012; Zhang, M et al. 2013). To engineer this protein we took advantage of the N-terminus of ClyA. The N-terminus of ClyA, which is highly hydrophobic (Oscarsson J et al), undergoes a conformational change to insert into the target cell membrane (Oscarsson J et al). This conformational change allows ClyA to penetrate the target membrane to form a transmembrane domain of ClyA. The hydrophobic nature of lipid membranes makes it highly unfavorable for any charged residues to cross the membrane (Hunt J 1997). With this in mind, we hypothesize that negative charges inserted into the N-terminus of ClyA will inhibit it from inserting into the membrane. Thus, we mutated the N-terminus of the ClyA protein by inserting an inactivation site composed of negatively charged amino acids that we hypothesize would prevent insertion into the plasma membrane of the target cell. Once we confirmed that this construct was an inactive ClyA mutant, we inserted a thrombin cleavage site right after the inserted negative charges. This site should allow us to remove the negative charges once the protein is exposed to thrombin. Once the negative charges are removed, the protein should recover its activity. This approach will allow us to create a version of ClyA that is protease-switchable.

Porous polysulfone membranes prepared by phase inversion can be tailored to suit filtration requirements by the choice of solvent and coagulant. In the current research polysulfone membranes were prepared by inverting a solution in N-methyl pyrrolidinone (NMP) in isopropanol to form uniform sized pores. Phase inversion resulted in the formation of an asymmetric membrane. The membranes have a characteristic "skin" which is supported by a highly porous substructure. Water-wet membranes experience capillary force during water evaporation. Since the modulus of the membranes is lower than the capillary force, the membrane walls shrink and thicken giving rise to a condensed structure. The "skin" regulates permeation through the membranes which is essential for filtration. A change in the pore structure of the skin alters the permeability. The current research investigates the influence of amine plasma treatments on the surface pore structure of polysulfone membranes. The permeation of a rhodamine dye through the plasma treated membranes and through non-plasma treated membranes is used to examine the influence of the plasma treatment. Furthermore, the influence of plasma treatment on the loss of water from the membranes leading to pore collapse is also explored. The study revealed that a plasma ablates the skin, increasing the permeation. An ammonia plasma treatment produced more etching, and hence increased permeation compared to permeation for an aniline plasma-treated membrane. A one-minute aniline plasma treatment only caused a moderate increase in permeation. Plasma treatments introduced significant surface modification by the introduction of new functionalities. However, permeation was not influenced by the surface modification. Water trapped in the pores is essential to maintain the pore structure of the membrane. The surface treatment dictates the pore size and therefore, the convection allowing water evaporation, leading to pore collapse. Heat treating also increases the rate of water removal. Using thermogravimetric analysis (TGA) and scanning electron microscopy (SEM) the role of heat and surface treatments on the extent of pore collapse was investigated. The ammonia plasma treated samples showed maximum water loss and the control samples showed a minimum loss of water when stored at room temperature. All the samples stored at 90 °C exhibited equivalent water loss. Water loss was not affected by the plasma treatments. / Ph. D.