Our Landscape, Ourselves: Integrating Process and Traditional food Principles for Wellbeing + Resilience in the Swinomish Tribal Community

Thesis (Master's)--University of Washington, 2016-08

Digital Media in Landscape Architecture Design Process

Thesis (Master's)--University of Washington, 2016-08

Floating Wetlands in the Puget Lowlands: Design, Construction, and Viability

Thesis (Master's)--University of Washington, 2016-06

Modelling interacting phenomena during the solidification of metals in the casting process

A variety of interacting complex phenomena takes place during the casting of metallic components. Here molten metal is poured into a mould cavity where it flows, cools, solidifies and then deforms in its solid state. As the metal cools, thermal gradients will promote thermal convection which will redistribute the heat around the component (usually from feeders or risers) towards the solidification front and mushy zone. Also, as the evolving solid regions of the cast component deform they will form gap at the cast-mould interface. This gap may change the rate of solidification in certain parts the casting, hence affecting the manner in which the cast component solidifies. Interaction between a cast component and its surrounding mould will also govern stress magnitudes in both the cast and mould -these may lead to defects such as cracks. This paper presents a multiphysics modelling approach to this complex process. Emphasis will be placed on the interacting phenomena taking place during the process and the modelling strategy used. Comparisons with plant data are also be given.

HPC management and engineering in the hybrid cloud

The evolution and maturation of Cloud Computing created an opportunity for the emergence of new Cloud applications. High-performance Computing, a complex problem solving class, arises as a new business consumer by taking advantage of the Cloud premises and leaving the expensive datacenter management and difficult grid development. Standing on an advanced maturing phase, today’s Cloud discarded many of its drawbacks, becoming more and more efficient and widespread. Performance enhancements, prices drops due to massification and customizable services on demand triggered an emphasized attention from other markets. HPC, regardless of being a very well established field, traditionally has a narrow frontier concerning its deployment and runs on dedicated datacenters or large grid computing. The problem with common placement is mainly the initial cost and the inability to fully use resources which not all research labs can afford. The main objective of this work was to investigate new technical solutions to allow the deployment of HPC applications on the Cloud, with particular emphasis on the private on-premise resources – the lower end of the chain which reduces costs. The work includes many experiments and analysis to identify obstacles and technology limitations. The feasibility of the objective was tested with new modeling, architecture and several applications migration. The final application integrates a simplified incorporation of both public and private Cloud resources, as well as HPC applications scheduling, deployment and management. It uses a well-defined user role strategy, based on federated authentication and a seamless procedure to daily usage with balanced low cost and performance.

Modeling of burden distribution in the blast furnace

The blast furnace is the main ironmaking production unit in the world which converts iron ore with coke and hot blast into liquid iron, hot metal, which is used for steelmaking. The furnace acts as a counter-current reactor charged with layers of raw material of very different gas permeability. The arrangement of these layers, or burden distribution, is the most important factor influencing the gas flow conditions inside the furnace, which dictate the efficiency of the heat transfer and reduction processes. For proper control the furnace operators should know the overall conditions in the furnace and be able to predict how control actions affect the state of the furnace. However, due to high temperatures and pressure, hostile atmosphere and mechanical wear it is very difficult to measure internal variables. Instead, the operators have to rely extensively on measurements obtained at the boundaries of the furnace and make their decisions on the basis of heuristic rules and results from mathematical models. It is particularly difficult to understand the distribution of the burden materials because of the complex behavior of the particulate materials during charging. The aim of this doctoral thesis is to clarify some aspects of burden distribution and to develop tools that can aid the decision-making process in the control of the burden and gas distribution in the blast furnace. A relatively simple mathematical model was created for simulation of the distribution of the burden material with a bell-less top charging system. The model developed is fast and it can therefore be used by the operators to gain understanding of the formation of layers for different charging programs. The results were verified by findings from charging experiments using a small-scale charging rig at the laboratory. A basic gas flow model was developed which utilized the results of the burden distribution model to estimate the gas permeability of the upper part of the blast furnace. This combined formulation for gas and burden distribution made it possible to implement a search for the best combination of charging parameters to achieve a target gas temperature distribution. As this mathematical task is discontinuous and non-differentiable, a genetic algorithm was applied to solve the optimization problem. It was demonstrated that the method was able to evolve optimal charging programs that fulfilled the target conditions. Even though the burden distribution model provides information about the layer structure, it neglects some effects which influence the results, such as mixed layer formation and coke collapse. A more accurate numerical method for studying particle mechanics, the Discrete Element Method (DEM), was used to study some aspects of the charging process more closely. Model charging programs were simulated using DEM and compared with the results from small-scale experiments. The mixed layer was defined and the voidage of mixed layers was estimated. The mixed layer was found to have about 12% less voidage than layers of the individual burden components. Finally, a model for predicting the extent of coke collapse when heavier pellets are charged over a layer of lighter coke particles was formulated based on slope stability theory, and was used to update the coke layer distribution after charging in the mathematical model. In designing this revision, results from DEM simulations and charging experiments for some charging programs were used. The findings from the coke collapse analysis can be used to design charging programs with more stable coke layers.

Sub lethal mercuric chloride toxicity induced stress related alterations in the epithelial lining of foot of the freshwater mussel Lamellidens marginalis (Lamarck)

Sub lethal (0.2 ppm) mercuric chloride induced stress related histopathological alterations in the epithelial linings of foot (podium) of the edible freshwater mussel Lamellidens marginalis (Lamarck) were studied using histochemical techniques up to 60 days of exposure. The histomorphological changes were manifested only slowly and its intensity was somewhat proportional to the duration of exposure. The immediate response of the exposed mussels was the altered mucous secretion. There was a progressive incorporation of sulphated glycoproteins into the secretory contents of the mucous cells especially in the first half of the experiment. Marked histopathological changes including necrosis, appearance of pyknotic nuclei, sloughing of epithelial cells and appearance of non-tissue spaces, etc., started appearing during the later half of the experiment. The fag end of the experiment, which witnessed prominent histomorphological changes, was accompanied by highly decreased mucous secretion. KEYWORDS: heavy metal toxicity, mercuric chloride, Lamellidens marginalis, freshwater mussel, histopathology.

Hydrothermal carbonization in the synthesis of sustainable porous carbon materials

Carbon materials are found versatile and applicable in wide range of applications. During the recent years research of carbon materials has focussed on the search of environmentally friendly, sustainable, renewable and low-cost starting material sources as well as simple cost-efficient synthesis techniques. As an alternative synthesis technique in the production of carbon materials hydrothermal carbonization (HTC) has shown a great potential. Depending on the application HTC can be performed as such or as a pretreatment technique. This technique allows synthesis of carbon materials i.e. hydrochars in closed vessel in the presence of water and self-generated pressure at relatively low temperatures (180-250 ˚C). As in many applications well developed porosity and heteroatom distribution are in a key role. Therefore in this study different techniques e.g. varying feedstock, templating and post-treatment in order to introduce these properties to the hydrochars structure were performed. Simple monosaccharides i.e. fructose or glucose and more complex compounds such as cellulose and sludge were performed as starting materials. Addition of secondary precursor e.g. thiophenecarboxaldehyde and ovalbumin was successfully exploited in order to alter heteroatom content. It was shown that well-developed porosity (SBET 550 m2/g) can be achieved via one-pot approach (i.e. exploitation of salt mixture) without conventionally used post-carbonization step. Nitrogen-enriched hydrochars indicated significant Pb(II) and Cr(VI) removal efficiency of 240 mg/g and 68 mg/g respectively. Sulphur addition into carbon network was not found to have enhancing effect on the adsorption of methylene blue or change acidity of the carbon material. However, these hydrochars were found to remove 99.9 % methylene blue and adsorption efficiency of these hydrochars remained over 90 % even after regeneration. In addition to water treatment application N-rich high temperature treated carbon materials were proven applicable as electrocatalyst and electrocatalyst support. Hydrothermal carbonization was shown to be workable technique for the production of carbon materials with variable physico-chemical properties and therefore hydrochars could be applied in several different applications e.g. as alternative low-cost adsorbent for pollutant removal from water.

Survey of past, present pollutants via sediment cores analysis in the coastal trend of Caspian Sea

This is especially well supported by down core variation Zn concentration. As Caspian Sea water intrudes into the Bay, it may be concluded that some part of pollution has sea origin. The geochemical index (Igeo) was reformulated for the area of study using chemical partitioning as well as Pb-210 results. The newly developed geochemical index is indicative of low to medium pollution intensity in the Bay of Gorgan. Thus, any additional pollution into the area of study may leave adverse effects on the aquatic ecology of Bay of Gorgan. Further, lithogenous and non-lithogenous inputs of metals into the Bay were assessed. For this purpose and through chemical partitioning, association of metals with different sedimentary phases was determined. The overall results show that about 114th total metal concentration have been added into the Bay of Gorgan through human activities.

The role of automated sorting in the recovery of aluminium alloys waste

Selected papers from the 3rd Edition of the International Conference on Wastes: Solutions, Treatments and Opportunities

The role of microRNA 21 in the development of in-stent restenosis

Coronary heart disease is a major cause of morbidity and mortality worldwide. Percutaneous coronary intervention (PCI) has become the most widely used method of coronary artery revascularisation. The use of stents to hold open atherosclerosis induced arterial narrowing has significantly reduced elastic recoil and acute vessel occlusion following balloon angioplasty. However, bare metal stents have been associated with in-stent restenosis attributed to vascular smooth muscle cell (VSMC) hyperplasia and excessive neointimal formation. The resultant luminal renarrowing may manifest clinically with the return of symptoms such as chest pain or shortness of breath. The development of drug eluting stents has significantly reduced the incidence of in-stent restenosis (ISR). Unfortunately the antiproliferative medications used not only inhibit VSMC proliferation but also re-endothelialisation of the stented vessel. In addition, the drug impregnated polymer coating has been associated with a chronic inflammatory response within the vessel wall predisposing patients to stent thrombosis. Thus the identification of novel therapies which promote vessel healing without excessive proliferative or inflammatory response may improve long term outcome and reduce the need for repeated revascularisation. MicroRNAs (miRs) are short (18-25 nucleotide) non-coding RNAs acting to regulate gene expression. By binding to the 3’untranslated region of mRNA they act to fine tune gene expression either by mRNA degradation or translational repression. Originally identified in coordinating tissue development microRNAs have also been shown to play important roles coordinating the inflammatory response and in numerous cardiovascular diseases. MiR-21 has been identified in human atherosclerotic plaques, arteriosclerosis obliterans and abdominal aortic aneurysms. In addition, its up regulation has been documented in preclinical models of vascular injury. This study sought to identify the role of miR-21 in the development of ISR. Utilising a small animal model of stenting and in vitro techniques, we sought to investigate its influence upon VSMC and immune cell response following stenting. 19 The refinement of a murine stenting model within the Baker laboratory and the electrochemical dissolution of the metal stent from within harvested vascular tissues significantly improved the ability to perform detailed histological analysis. In addition, identification of miRNAs using in situ hybridisation was achieved for the first time within stented tissue. Neointimal formation and ISR was significantly reduced in mice in which miR-21 had been genetically deleted. In addition, neointimal composition was found to be altered in miR-21 KO mice with reductions in VSMC and elastin content demonstrated. Importantly, no difference in re-endothelialisation was observed. In vitro analysis demonstrated that VSMCs from miR-21 KO mice had both reduced proliferative and migratory capacity following platelet derived growth factor stimulation. Molecular analysis revealed that these differences may, at least in part, be due to de-repression of programmed cell death 4 (PDCD4). PDCD4 is a known miR-21 target within VSMCs implicated in the suppression of proliferation and promotion of apoptosis. Unfortunately, initial attempts at antimiR mediated knockdown of miR-21 in vivo, failed to produce a similar change in the suppression of ISR. Furthermore, a significant alteration in macrophage polarisation state within the neointima of miR-21 WT and KO mice was noted. Immunohistochemical staining revealed a preponderance of anti-inflammatory M2 macrophages in KO mice. Analysis of bone marrow derived macrophages from miR-21 KO mice demonstrated an increased level of the peroxisome proliferation activating receptor-γ (PPARγ) which facilitates M2 polarisation. Importantly, significant alterations in numerous pro-inflammatory cytokines, which also have mitogenic effects, were also found following genetic deletion of miR-21. In Summary, this is the first study to look at miRs in the development of ISR. MiR-21 plays an important role in the development of ISR by influencing the proliferative response of VSMCs and modulating the immune response following stent deployment. Further attempts to modulate miR-21 expression following PCI may reduce ISR and the need for repeat revascularisation while also reducing the risk of stent thrombosis.

Development of gene expression-based biomarkers of exposure to metals and pesticides in the freshwater amphipod Hyalella azteca

Ecological risk assessment (ERA) is a framework for monitoring risks of exposure and adverse effects of environmental stressors to populations or communities of interest. One tool of ERA is the biomarker, which is a characteristic of an organism that reliably indicates exposure to or effects of a stressor like chemical pollution. Traditional biomarkers which rely on characteristics at the tissue level and higher often detect only acute exposures to stressors. Sensitive molecular biomarkers may detect lower stressor levels than traditional biomarkers, which helps inform risk mitigation and restoration efforts before populations and communities are irreversibly affected. In this study I developed gene expression-based molecular biomarkers of exposure to metals and insecticides in the model toxicological freshwater amphipod Hyalella azteca. My goals were to not only create sensitive molecular biomarkers for these chemicals, but also to show the utility and versatility of H. azteca in molecular studies for toxicology and risk assessment. I sequenced and assembled the H. azteca transcriptome to identify reference and stress-response gene transcripts suitable for expression monitoring. I exposed H. azteca to sub-lethal concentrations of metals (cadmium and copper) and insecticides (DDT, permethrin, and imidacloprid). Reference genes used to create normalization factors were determined for each exposure using the programs BestKeeper, GeNorm, and NormFinder. Both metals increased expression of a nuclear transcription factor (Cnc), an ABC transporter (Mrp4), and a heat shock protein (Hsp90), giving evidence of general metal exposure signature. Cadmium uniquely increased expression of a DNA repair protein (Rad51) and increased Mrp4 expression more than copper (7-fold increase compared to 2-fold increase). Together these may be unique biomarkers distinguishing cadmium and copper exposures. DDT increased expression of Hsp90, Mrp4, and the immune response gene Lgbp. Permethrin increased expression of a cytochrome P450 (Cyp2j2) and decreased expression of the immune response gene Lectin-1. Imidacloprid did not affect gene expression. Unique biomarkers were seen for DDT and permethrin, but the genes studied were not sensitive enough to detect imidacloprid at the levels used here. I demonstrated that gene expression in H. azteca detects specific chemical exposures at sub-lethal concentrations, making expression monitoring using this amphipod a useful and sensitive biomarker for risk assessment of chemical exposure.

Spliceosomal small nuclear ribonucleoprotein particle trafficking and maturation in the nuclear compartment

We show for the first time that upon injection into the cytoplasm of the oocyte, fluorescein-labeled spliceosomal snRNAs, in the context of functional snRNPs, are targeted to elongating pre-mRNAs. This finding presents us with a novel assay with which to dissect the mechanism by which snRNPs are targeted to nascent pre-mRNA transcripts. Two critical advantages offered by this system are immediately evident. First, it allows us to investigate the mechanisms employed to recruit snRNPs as it actually transpires within the realm of the cell nucleus. Second, it allows a genome-wide analysis of snRNP recruitment to nascent transcripts, and, hence, the conclusions drawn from these studies do not depend on the sequence of any particular promoter or pre-mRNA. Indeed, it is with this assay that we have stumbled upon a most unanticipated discovery: Contrary to the current paradigm, the co-transcriptional recruitment of splicing snRNPs to nascent transcripts is not contingent on their role in splicing in vivo. Based on these and other data, we have constructed a two-step recruitment-loading model wherein snRNPs are first recruited to pre-mRNA transcripts and only then loaded directly onto cis-acting sequences on nascent pre-mRNA. While conducting studies on snRNP trafficking, a new discovery was made. We found that the lampbrush chromosomes could be visualized by light microscopy in vivo, and that these chromosomes have an architecture that is identical with those in formaldehyde treated nuclear spread preparations. Importantly, we now have the first system with which we can examine the dynamic interactions of macromolecules with specific RNA polymerase II transcriptional units in the live nucleus.

A functional specification and validation model for networks on chip in the ACL2 logic

International audience