We examine the structural complexities of a 28-km long part of the Clark fault of the San Jacinto fault zone in southern California in order to better document its lateral extent and the style of deformation of its southeast end. Changes in structural style are observed as the Clark fault’s damage zone widens from ~ 1-2 km in crystalline rocks of the Peninsular Ranges southeastward to ~ 18 km in the sedimentary rocks of the San Felipe-Borrego subbasin of the Salton Trough. The Clark fault extends into the San Felipe-Borrego subbasin as the Arroyo Salada segment for ~ 11-12 km to a newly defined northeast-trending structural boundary. This structural boundary, referred to herein as the Pumpkin Crossing block, is a ~ 3-km wide and ~ 8-km long fault zone dominated by northeast-striking sinistral-normal strike-slip faults. Southeast of the Pumpkin Crossing block the newly defined San Felipe Hills segment extends the Clark fault another ~12-13 km southeast to its intersection with the Extra fault zone. The Clark fault may have nearly 14.5-18 km of right separation represented in the surface deformation of the Arroyo Salada and San Felipe Hills segments, but the total amount of strain is masked by the wide diffuse fault zone with its complex deformation patterns and geometries. The lateral change observed in microseismicity patterns across the Arroyo Salada and San Felipe Hills segment boundary supports our structural interpretations about the existence, location, and structure of this boundary. Vertical patterns in the microseismicity suggest that the Clark fault zone narrows at depth, dips steeply northeast in the subsurface, and must interact with at least one weak decollement layer(s) beneath and/or with the sedimentary basin. Structural deformation within the late Miocene to Holocene silty- and clay-rich sedimentary basin of the Salton Trough includes features characteristic of strike-slip faults, such as stepovers, conjugate faults, folds, flower structures, and fault bends, as well as many unique structures that include pooch structures, ramp-flat geometries of strike-slip faults, complex en echelon fault zones with localized shear distributed across a high frequency network of faults, and heterogeneous kinematic indicators within individual fault zones.

Thesis (MSc. (Chemistry)) -- University of Limpopo, 2013 / Drinkable water is water that is safe enough to be consumed by humans or used with low risk of immediate or long term harm. World-wide, insufficient access to portable water and use of sources contaminated with disease vectors, pathogens, and unacceptable levels of toxins is a huge problem. The use of such water for drinking and food preparation leads to the widespread of acute and chronic illnesses. This is a major cause of death and misery in many undeveloped countries. Reduction of waterborne diseases is a major public health goal in developing countries. Nanotechnology offers the possibility of an efficient removal of pollutants and microorganisms from water. Essentially, three classes of nanoscale materials were investigated as functional materials for water purification in this study. Silver nanoparticles, carbon nanotubes and beta ()-cyclodextrin polymers were synthesised and characterised specifically for purification of water samples. β-cyclodextrin is soluble in both water and other aqueous media. In order to render cyclodextrins insoluble, they were converted into highly cross-linked polymers, by polymerisation with a bifunctional linker, hexamethylene diisocyanate. Cyclodextrins were functionalised and synthesised with either the allyl or the benzoyl group. Characterisation with fourier transform infrared (FTIR) spectrophotometer confirmed the functionalisation process. Thereafter the scanning electron microscopy (SEM) analysis confirmed the polymers’ morphology to be spongy, and capable of absorbing contaminants. Multi-walled carbon nanotubes (MWCNTs) were treated with a mixture of sulphuric and nitric acid in order to introduce the carboxyl and hydroxyl groups. These were characterised by SEM, transmission electron microscopy (TEM), X-ray diffraction (XRD) and FTIR spectroscopy to confirm the functionalisation process. Silver nanoparticles were synthesised from sodium citrate and silver nitrate, using sodium dodecyl sulphate as a surfactant. Their characterisation was done by SEM, energy dispersive X ray (EDX) spectroscopy, TEM, UV/Vis spectroscopy and XRD to confirm a face centred cubic structure with an estimated crystallite size ranging from 50 to 100 nm.β-cyclodextrin polymers, functionalised multi-walled carbon nanotubes and silver nanoparticle-doped MWCNTs/cyclodextrin composites were characterised by SEM, TEM, XRD, Brunauer-Emmet-Teller (BET) and EDX. Analysis of the phenolic compound, 4-hydroxynitrobenzene in water, using these nanocomposites, demonstrated good capabilities of removing organic contaminants from water samples as indicated by their high absorption efficiencies of the contaminants. The synthesised metal-organic composites were tested for their effectiveness in removing organic contaminants as well as for eliminating Escherichia coli bacteria from water. The synthesised composites presented up to 97% absorption efficiency of organic contaminants and up to 100% inactivation of the bacteria. There was complete destruction of bacteria from the water analysed at various times and varying concentrations. After a long exposure of the nanocomposites to E. coli, pits were noticeable on the external morphology of the bacteria, thus suggesting that the nanocomposites are bactericidal. The bacterial activity increased with temperature,when studied between 10 oC and 30 oC.

This study was carried out on algal biofilms grown using rotating algal biofilm reactors (RABRs) with the aim of: i) characterizing their growth in terms of photosynthetic activity and morphology ii) evaluating their performance as a wastewater treatment option and a feedstock for biofuels production, and iii) examining the algal-bacteria interactions. A review of algal biofilm technologies currently employed in wastewater treatment processes was made to compare nutrient removal efficiencies, factors that influenced algal biofilm growth, and the different bioproducts generated from algal biomass. Consequently, research efforts were directed towards addressing pertinent issues identified in literature in order to optimize these systems for wastewater treatment and bioproducts production. Successful growth of algal biofilms in municipal wastewater and subsequent removal of nutrients from the wastewater was demonstrated. Photosynthetic and respiration rates observed with depth of the biofilm were influenced by the biofilm composition (single vs. mixed species), culturing conditions (laboratory vs. outdoor), orientation to the light, nitrogen availability (N-replete vs. N-deplete), and dissolved inorganic carbon availability (presence or absence of bicarbonate). Slight enhancement in lipid production was also observed as a result of nitrogen stress and bicarbonate addition. However, the accumulated lipids were not as much as expected or as reported in suspended cultures. Presence of bacteria positively influenced microalgae growth in the mixed cultures but the reverse was not true. In conclusion, photosynthetic activity and biofilm structure were characterized with methods developed for the algal biofilms in this study. For now, productivity of the algal biofilms needs to be maximized in order to fully utilize its potential as a biofuel feedstock and nutrient removal option. Further research on algae-bacteria interactions using species native to the wastewater grown algal biofilms is recommended.

Probiotics are living organisms which exert a beneficial health effect when consumed in sufficient numbers. Consumer interest in probiotics has increased dramatically in recent years prompting an increase in production and development of functional foods. One major problem is the decreased viability of probiotic bacteria during functional food production and storage and subsequent digestion due to environmental stresses. The most common probiotic strains belong to the genus Lactobacillus or Bifidobacterium. Due to the anaerobic nature of these bacteria, they lack the required defense mechanisms for oxidative stress inherent in aerobic microorganisms. This study examined the oxidative stress responses of six strains of Bifidobacterium, which are commonly used as probiotics in functional foods.The first phase of the study investigated the innate and inducible hydrogen peroxide (H2O2) stress response of Bifidobacterium longum strains NCC2705 and D2957, Bifidobacterium longum ssp. infantis ATCC 15697, and Bifidobacterium animalis ssp. lactis strains BL-04, DSM10140 and RH-1. Strains were screened for survival at increasing concentrations of H2O2 and lethal and sublethal concentrations were determined for each. In the second phase, B. animalis ssp. lactis strains BL-04 and DSM10140 and B. longum strains NCC2705 and D2957 were treated with a sublethal H2O2 concentration and RNA samples were collected for transcriptome analysis after 5 min and either 20 or 60 min. Statistical analysis was performed to identify genes that increased or decreased in expression during H2O2 treatment compared to control cells.Results showed that survival was species and strain dependent and that strains which naturally survived higher H2O2 concentrations had a larger number of differentially expressed genes early on during H2O2 exposure. Some of the protective genetic systems that were activated during H2O2 stress are mechanisms which perform basic cellular functions under normal conditions such as deoxuynucleotide synthesis. Under stress conditions, these systems can be used to detoxify oxidative free radicals. Also a number of genes involved in sugar transport and energy production for the cell showed increased expression, which reveals the increased energy needs of the cells during oxidative stress.During testing, it was found that two B. animalis ssp. lactis strains, BL-04 and DSM10140, had differing levels of survival and gene expression during H2O2 exposure despite having almost identical genome sequences. It was determined that one possible cause of the differences was a genetic deletion in a gene that allows the cell to incorporate extracellular fatty acids into the cell membrane instead of synthesizing them.Results from this project have increased the understanding of oxidative stress responses in bifidobacteria and highlighted possible methods to increase bacterial survival during food manufacture, storage, and human digestion.

Measurements of the mechanical properties of lithium-ion battery electrode films can be used to quantify and improve manufacturing processes and to predict the mechanical and electrochemical performance of the battery. This thesis demonstrates the use of acoustic resonances to distinguish among commercial-grade battery films with different active electrode materials, thicknesses, and densities. Resonances are excited in a clamped circular area of the film using a pulsed infrared laser or speaker and responses are measured using an electret condenser microphone. A numerical model is used to quantify the sensitivity of resonances to changes in mechanical properties. When the numerical model is compared to simple analytical models for thin plates and membranes, the battery films measured here trend more similarly to the membrane model. Resonance measurements are also used to monitor the drying process. Results from a scanning laser Doppler vibrometer verify the modes excited in the films, and a combination of experimental and simulated results is used to estimate the Young's modulus of the battery electrode coating layer.

<p>Høye poretrykk utgjør en risiko for boreoperasjoner på Norsk Sokkel og internasjonalt. Denne risikoen kan reduseres dersom man har kjennskap til poretrykksforholdene før boring. Poretrykk er også en viktig parameter for felt i produksjon, og kunnskap om hvordan dette utvikler seg over tid vil kunne ha stor betydning for økt oljeutvinning. Seismiske data inneholder informasjon om poretrykket og kan derfor bidra til økt kunnskap på dette området. Avhandlingen tar for seg hvordan hastighets- og amplitudeinformasjon fra seismiske data kan brukes for å estimere poretrykk.</p> / <p>Abnormally high pore pressures in the subsurface pose a hazard to drilling operations worldwide. The problem is not unusual on the Norwegian Continental Shelf. Knowledge of the pore pressure prior to drilling may reduce the risk related to drilling in high pressure zones. Pore pressure is also a vital paramter for producinig fields, and knowledge of how the pressure develops over time can be important for increased oil recovery. Seismic data contain information on the pore pressure and may contribute to increased understanding of subsurface pressure conditions. The thesis deals with methods for estimation of pressure from seismic velocity and amplitude data.</p>

The motivation to study this non-classical CMOS device is necessary to face with the ITRS constraints. In the ITRS roadmap, the gate length of devices are being scaled down rapidly but this rapid scaling is not in pace with the relatively slow scaling of the gate equivalent oxide thickness which leads to a degradation in the performance of the transistor. One of the solutions to this problem is the use of non-classical devices, such as the Gate-All-Around (GAA) MOSFET. Owing to the flexibility of SOI technology, these novel devices can be adapted to this technology bringing along with it the benefit of SOI technology. One of the main advantage of building this GAA device on SOI technology is that it offers the possibility whereby the second gate is easily built into the back of the device. GAA devices are also interesting because they do not need to scale down the thickness of the gate oxide rapidly but still able to maintain a suitable thickness to avoid problems such as current leakage through the thin gate oxide by tunnelling. The objective of this research can be divided into three parts; the first is to study the feasibility of the various fabrication process for this GAA device, the second to analyse the electrical characteristics of these fabricated GAA devices from DC characteristics up to 110 GHz and the third one is the use of commercial numerical simulation softwares (IE3D, Silvaco) in order to describe the physics of these novel devices. In this study, these different structures shows advantages and disadvantages when used in either analog or RF applications. The graded-channel structure has shown that it is advantageous when used in high performance analog circuits. The advantages of this structure is further enhanced when it is combined with the double-gate structure, forming a double-gate graded channel SOI MOSFET. Optimizing in terms of doping level along the channel of the graded-channel is important to yield good electrical results. In order for these devices to be successful commercially, it is important that they are compatible with the fabrication technology and trends available today and in the near future. To confirm that these devices can be adapted into today's and tomorrow's technology, we have shown that these they are easily adaptable in the current technology. Multiple-gate devices are a new group of devices which have been identified by ITRS as potential devices to meet the demands in the future. In this study, we have shown that these multiple-gate devices do indeed show improved short-channel effects and improved analog and RF characteristics when compared to the single-gate devices in existence. One of the main contributors to these improvements is due to what is known as the “volume inversion”.

Recent efforts to optimize oil recovery from Green River reservoirs, Uinta Basin, have stimulated the need for better understanding of the reservoir connectivity at the scale of the operational unit. This study focuses on Green River reservoirs in the Wells Draw study area where oil production response to implemented waterflood is poor and a better understanding of the reservoir connectivity is required to enhance future secondary oil recovery. Correlating the sand bodies between well locations in the area remains difficult at 40-acre well spacing. Thus, interwell connectivity of the reservoirs is uncertain. Understanding the reservoir connectivity in the Wells Draw study area requires integration of all static and dynamic data for generation of probabilistic models of the reservoir at the interwell locations. The objective of this study is two-fold. The first objective was to determine reservoir connectivity at the interwell scale in the Wells Draw study area. To achieve this goal, I used well log and perforation data in the Wells Draw study area to produce probabilistic models of net-porosity for four producing intervals: (1) Castle Peak, (2) Lower Douglas Creek, (3) Upper Douglas Creek, and (4) Garden Gulch. The second objective was to find readily applicable methods for determining interwell connectivity. To achieve this goal, I used sandstone net thickness and perforation data to evaluate interwell connectivity in the Wells Draw study area. This evaluation was done to: (1) assess and visualize connectivity, (2) provide an assessment of connectivity for validating / calibrating percolation and capacitance based methods, and (3) determine flow barriers for simulation. The probabilistic models encompass the four producing intervals with a gross thickness of 1,900 ft and enable simulation assessments of different development strategies for optimization of oil recovery in the Wells Draw study area. The method developed for determining interwell connectivity in Wells Draw study area is reliable and suited to the four producing intervals. Also, this study shows that the percolation based method is reliable for determining interwell connectivity in the four producing intervals.

Høye poretrykk utgjør en risiko for boreoperasjoner på Norsk Sokkel og internasjonalt. Denne risikoen kan reduseres dersom man har kjennskap til poretrykksforholdene før boring. Poretrykk er også en viktig parameter for felt i produksjon, og kunnskap om hvordan dette utvikler seg over tid vil kunne ha stor betydning for økt oljeutvinning. Seismiske data inneholder informasjon om poretrykket og kan derfor bidra til økt kunnskap på dette området. Avhandlingen tar for seg hvordan hastighets- og amplitudeinformasjon fra seismiske data kan brukes for å estimere poretrykk. / Abnormally high pore pressures in the subsurface pose a hazard to drilling operations worldwide. The problem is not unusual on the Norwegian Continental Shelf. Knowledge of the pore pressure prior to drilling may reduce the risk related to drilling in high pressure zones. Pore pressure is also a vital paramter for producinig fields, and knowledge of how the pressure develops over time can be important for increased oil recovery. Seismic data contain information on the pore pressure and may contribute to increased understanding of subsurface pressure conditions. The thesis deals with methods for estimation of pressure from seismic velocity and amplitude data.

Higher plants cannot move to a more favorable place when the environmental conditions are changing. To adapt to changes in light, temperature and access to water the plants had to evolve special mechanisms at the molecular level. Post-translational modifications of proteins, like phosphorylation, often serve as “on-and-off” switches in regulation of cellular activity and may affect protein-protein interactions. Photosynthesis in higher plants is regulated by reversible protein phosphorylation events, in a unique light- and redox-controlled system. Several biochemical methods are effectively used for characterization of phosphorylated proteins in photosynthetic membranes. Nevertheless, mass spectrometry is the most effective technique when it comes to identification of exact phosphorylation site(s) in the protein sequence, which is the ultimate evidence of protein phosphorylation. The same tandem mass spectrometry analysis identifies other in vivo post-translational modifications as well, such as acetylation of the N-terminus of mature protein. To study membrane proteins is a challenging project. In the present work the “shaving” of surface-exposed part of the membrane proteins, where phosphorylation occur, is used. In combination with mass spectrometry, this technique does not require the use of radioactive labeling or antibodies. The present work in spinach and Arabidopsis thaliana has identified and characterized several known phosphoproteins, new phosphorylation sites in well-known photosynthetic proteins, as well as two phosphoproteins previously unknown to be present in the photosynthetic membrane. Several photosystem II (PSII) core proteins become phosphorylated in their N-termini (D1, D2, CP43, PsbH), process involved in the regulation of the repair cycle of photo-damaged PSII complexes. The protein-protein interactions between PSII and its light harvesting complex (LHCII) seem to be affected by phosphorylation events in the interface area. In higher plants, phosphorylation sites have been identified in LHCII polypeptides, in one of the proteins (CP29) present in the interface area, as well as in the peripheral TSP9 protein. The TSP9 protein is unique among photosynthetic phosphoproteins, since it is a plant-specific soluble protein that becomes triple-phosphorylated in the middle part of the protein. It is also shown that photosystem I (PSI) is subjected to protein phosphorylation. The extrinsic PSI subunit PsaD becomes phosphorylated in its N-terminus. In addition, the latest characterized subunit of PSI, PsaP, is identified as a phosphoprotein. PsaP is an intrinsic protein assembled on the same side of the PSI complex as LHCII attaches. Several kinases are involved in phosphorylation of photosynthetic proteins, some more specific to PSII core proteins whereas others recognize LHCII proteins better. The STN8 kinase does not phosphorylate LHCII proteins, but is involved in the phosphorylation of the PSII core proteins D1, D2, CP43 and PsbH. STN8 is light-activated and is also specific in phosphorylation of threonine-4 (Thr-4) in the PsbH protein, but only after another kinase has phosphorylated Thr-2 first. A common feature of all kinases in plant photosynthetic membranes is the specificity for Thr residues and that the phosphorylation reactions occur in the N-terminal sequence of the proteins, except for the TSP9 protein. Nowadays, research is on the way to solve the complex network of regulation of photosynthetic activity via protein phosphorylation, but far more efforts are needed to get a complete view of the importance of all phosphorylation events and enzymatic specificity.