Meltwater reaching the base of the snowpack may either infiltrate the underlying stratum, run off, or refreeze, forming a basal ice layer. Frozen ground underneath a melting snowpack constrains infiltration promoting runoff and refreezing. Compositional changes in chemistry take place for each of these flowpaths as a result of phase change, contact between meltwater and soil, and mixing between meltwater and soil water. Meltwater ion concentrations and infiltration rate into frozen soils both decline rapidly as snowmelt progresses. Their temporal association is highly non-linear and the covariance must be compensated for in order to use time-averaged values to calculate chemical infiltration over a melt event. This temporal covariance is termed �enhanced infiltration� and represents the additional ion load that infiltrates due to the timing of high meltwater ion concentration and infiltration rate. Both theoretical and experimental assessments of the impact of enhanced infiltration showed that it causes a greater ion load to infiltrate leading to relative dilute runoff water. Sensitivity analysis showed that the magnitude of enhanced infiltration is governed by initial snow water equivalent, average melt rate, and meltwater ion concentration factor. Based on alterations in water chemistry due to various effects, including enhanced infiltration, three major flowpaths could be distinguished: overland flow, organic interflow, and mineral interflow. Laboratory experiments were carried out in a temperature-controlled environment to identify compositional changes in water from these flowpaths. Samples of meltwater, runoff, and interflow were filtered and analyzed for major anions and cations. Chemical signatures for each flowpath were determined by normalizing runoff and interflow concentrations using meltwater concentrations. Results showed that changes in ion concentrations were most significant for H⁺, NO₃^�, NH₄⁺, Mg²⁺, and Ca²⁺. Repeated flushes of meltwater through each interflowpath caused a washout of ions. In the field, samples of soil water and ponding water were collected daily from a Rocky Mountain hillslope during snowmelt. Their normalized chemical compositions were compared to the laboratory-identified signatures to evaluate the flowpath. The majority of the flowpaths sampled had chemical signatures, which indicated mineral interflow, only 10% showed unmixed organic interflow.

The development of a non-invasive method of visualizing gene expression in larger animals could revolutionize some aspects of gene research by opening up a wider variety of animal systems to explore; some of which may be better models of human systems. Presently, most gene expression studies employ Green Fluorescent Protein (GFP) transfected into the genome of the animal system. For larger animals, an x-ray equivalent of GFP would be desirable due to the high penetrating power of x-rays. A model gene modification system is to use the Sodium (Na) Iodide Symporter (NIS) which will cause the accumulation of iodine in cells which express the NIS. To non-invasively observe the dilute iodine accumulated by the cancer cells transfected with NIS in the head of small animals, such as a rat, two synchrotron-based imaging methods were studied: K-Edge Subtraction (KES) imaging and Fluorescence Subtraction Imaging (FSI).<p> KES needs wide monochromatic x-ray beams at two energies bracketing the K-edge of the contrast agent existing or injected in the tissues. The monochromatic beam in the synchrotron facility normally is prepared by a double crystal monochromator. The appearance of the azimuthal angle (tilt error) in the double crystal monochromator creates intensity variations across the imaging field. This misalignment was studied through another two synchrotron-based imaging methods, Diffraction Enhanced Imaging (DEI) and Multi-Image Radiography (MIR), which show this problem clearly in their processed images. The detailed analysis of the effect of the tilt error, how it affects the resulting images, and how to quantify such an error were presented in the thesis. A post processing method was implemented and the artifacts caused by the improper experimental settings were discussed.<p> With the wide monochromatic beam prepared by the double crystal monochromator, a sequence of KES experiments were done and the detection limit of KES was quantified at a projected amount of 17.5mM-cm iodine in a physical model of a rat head with a radiation dose of 2.65mGy. With the raster scan of the object relative to the monochromatic pencil beam, FSI was studied to obtain higher Signal to Noise Ratio (SNR) for local area and better detection limit compared to KES. The detection limit of FSI was measured as a projected amount of 2.5mM-cm iodine in the same physical rat head with a tolerable radiation dose of 24mGy. According to the comparison of these two imaging techniques with references to imaging time and area, radiation dose, spatial resolution, and SNR, it was concluded that these two imaging techniques can be used complementarily in imaging dilute contrast material. Due to the short imaging time and large imaging area, KES is used first to provide a global view of the object, locate the area of interest, do the preliminary diagnosis, and decide whether the further FSI is necessary. Due to its high SNR for the dilute sample, FSI can be used when the area of interest is known. The combination of these two imaging techniques will be very promising and powerful. To facilitate the comparison of KES and FSI, a quality factor was developed to evaluate the performance of the imaging system.<p> The measured detection limits in our experiments are far beyond the thyroidal iodine concentration of a rat (around 1mM). To further improve the performance of KES, a bent Laue crystal monochromator was designed to do the simultaneous iodine KES imaging which overcomes the artifacts in the iodine image caused by the temporal difference for a single set of images. The designed monochromator can provide two separated x-ray beams bracketing the K-edge of iodine at the same time with a very high spatial resolution which is only depends on the source size, a very high energy resolution which can almost compete with that of the double crystal monochromator, and an acceptable photon flux.

Objective New biomarkers for acute kidney injury are needed and urinary Cystatin C is one alternative. The objective was to validate a urinary Cystatin C method on Mindray BS-380 comparing urine samples from the Uppsala Longitudinal Study of Adult Men (ULSAM-77) and urine samples from a reference group for Cystatin C. A visual control for a relationship between Cystatin C and C-reactive protein (CRP) and interleukin 6 (IL-6) respectively was made. Methods Precision, linearity, recovery, interference, and stability of the urine cystatin C method were investigated. Comparisons were made between ULSAM-77 samples and a reference group samples consisting of ordinary people. Results The highest total imprecision was 10.24 % for the sample with the lowest concentration. The second lowest concentration had 4.21 % total variation coefficient. The linearity equation was y = 0.99x – 0.01 with an R2-value of 0.99. The recovery for all concentrations was always 91 % or more. No interference from hemoglobin at a concentration of 10 g/L was found. The samples were stable at +5°C for seven days. The median for the samples from ULSAM-77 was 0.09 mg/L and the median for the reference samples was 0.06 mg/L. There was no obvious relationship between Cystatin C and CRP/IL-6 from ULSAM-77. Conclusion   Reliable data of urinary Cystatin C can be analyzed on a Mindray BS-380. The level of urinary Cystatin C was higher for people age 77 than for those with a median age of 49. There was no correlation between the concentration of Cystatin C in urine and the levels of CRP and IL-6.

Cystatin C, a 13 kDa low molecular weight protein is an inhibitor of cysteine proteases. Due to its low molecular weight and positive charge at physiological pH, it is freely filtered by the glomerulus and catabolized after reabsorption by proximal tubular cells with a low concentration (0.03-0.3 mg/L) in urine amongst healthy subjects. Urinary cystatin C is a potential biomarker detection of acute kidney injury (AKI) in the acute phase when patients are submitted to the intensive care unit. The aim in this report was to perform a full method validation of urinary analysis of cystatin C on a high throughput chemical analyzer by particle-enhanced turbidimetric immunoassay (PETIA) at the University Hospital in Uppsala, Sweden. The antigen excess, linearity, lower limit of quantification (LoQ), recovery, assay precision, stability and interference caused by haemoglobin was evaluated. No hook effect was observed, the assay was linear over the studied interval &lt;0.001-0.950 mg/L with a regression of R2=0.9994. The LoQ was calculated to 0.020 mg/L with a coefficient of variation (CV) ≤10% which was considered acceptable. The assay had a recovery between 93-100% and the assay precision had a total CV &lt;3.5%. Cystatin C is stable for 3 days in room temperature and 14 days in +4C. The assay did not show any major interference with haemoglobin. The urinary cystatin C showed good precision and performance characteristics by measurements using PETIA all of which is a necessary qualification for a biomarker at a 24-h running routine laboratory.

Bakgrund: ERAS (Enhanced Recovery After Surgery) är ett standardiserat multimodalt vårdprogram vid elektiv kolorektalkirurgi, som syftar till snabbare återhämtning och kortare vårdtider genom ett tvärprofessionellt samarbete.  En vecka innan planerad operation träffar sjuksköterskan patienten för ett samtal om vårdförloppet.   Syfte: Att identifiera och beskriva patientens upplevelse av sjuksköterskans ERAS- samtal och dess betydelse för patientens delaktighet i sin vård.    Metod: Datainsamlingen skedde genom kvalitativa intervjuer. Tolv patienter, nio män och tre kvinnor har intervjuats. De ljudinspelade samtalen har transkriberats ordagrant och analyserats med hjälp av tolkande fenomenologisk analys (Interpretative Phenomenological Analysis).   Resultat: Analysarbetet resulterade i fem olika teman; bli sedd, trygghet, tillit, ansvar samt delaktighet. Alla teman relaterar till varandra och illustrerar en positiv och en negativ sida av den upplevda erfarenheten. Tillsammans bildar en helhet av upplevelsen; ERAS- samtalet och dess betydelse för patientens delaktighet.   Konklusion: Resultatet visar att patienterna känner sig sedda under informationssamtalet. Det är viktigt att bekräfta patienten och knyta an mer till informationssamtalet under vårdtiden för att patienterna ska vara delaktiga och ta eget ansvar. Tilliten till vårdpersonalen har betydelse för att patienterna ska känna trygghet. Studien visar att ERAS- samtalet upplevs strukturerat och individuellt men informationen måste följa patienterna under hela vårdtillfället.

<p>The electromagnetic properties of various plasmonic nanostructures are investigated. These nanostructures, which include random clusters, controlled clusters and particle-film hybrids are applied to surface-enhanced Raman scattering (SERS). A variety of techniques are utilized to fabricate, characterize, and model these SERS-active structures, including nanoparticle functionalization, thin film deposition, extinction spectroscopy, elastic scattering spectroscopy, Raman scattering spectroscopy, single-assembly scattering spectroscopy, transmission electron microscopy, generalized Mie theory, and finite element method. </p><p>Initially, the generalized Mie theory is applied to calculate the near-field of the small random clusters to explain their SERS signal distribution. The nonlinear trend of SERS intensity versus size of clusters is demonstrated in experiments and near-field simulations. </p><p>Subsequently, controlled nanoparticle clusters are fabricated for quantitative SERS. A 50 nm gold nanoparticle and 20nm gold nanoparticles are tethered to form several hot spots between them. The SERS signal from this assembly is compared with SERS signals from single particles and the relative intensities are found to be consistent with intensity ratios predicted by near-field calculation.</p><p>Finally, the nanoparticle/film hybrid structure is studied. The scattering properties and SERS activity are observed from gold nanoparticles on different substrates. The gold nanoparticle on gold film demonstrates high field enhancement. Raman blinking is observed and implies a single molecule signal. Furthermore, the doughnut shape of Raman images indicates that this hybrid structure serves as nano-antenna and modifies the direction of molecular emission. </p><p>In additional to the primary gap dipole utilized for SERS, high order modes supported by the nanoparticle/film hybrid also are investigated. In experiments, the HO mode show less symmetry compared to the gap dipole mode. The simulation indicates that the HO modes observed may be comprised of two gap modes. One is quadrupole-like and the other is dipole-like in terms of near-field profile. The analytical treatment of the coupled dipole is performed to mimic the imaging of the quadrupole radiation.</p> / Dissertation

<p>The rising carbon dioxide emissions contributing to climate change has lead to the examination of potential ways to mitigate the environmental impact. One such method is through the geological sequestration of carbon (CCS). Although there are several different forms of geological sequestration (i.e. Saline Aquifers, Oil and Gas Reservoirs, Unminable Coal Seams) the current projects are just initiating the large scale-testing phase. The lead entry point into CCS projects is to combine the sequestration with enhanced oil recovery (EOR) due to the improved economic model as a result of the oil recovery and the pre-existing knowledge of the geological structures. The potential scope of CCS-EOR projects throughout the continental United States in terms of a systematic examination of individual reservoir storage potential has not been examined. Instead the majority of the research completed has centered on either estimating the total United States storage potential or the potential of a single specific reservoir.</p><p>The purpose of this paper is to examine the relationship between oil recovery, carbon dioxide storage and cost during CCS-EOR. The characteristics of the oil and gas reservoirs examined in this study from the Nehring Oil and Gas Database were used in the CCS-EOR model developed by Sean McCoy to estimate the lifting and storage costs of the different reservoirs throughout the continental United States. This allows for an examination of both technical and financial viability of CCS-EOR as an intermediate step for future CCS projects in other geological formations. </p><p>One option for mitigating climate change is to store industrial CO2 emissions in geologic reservoirs as part of a process known as carbon capture and storage (CCS). There is general consensus that large-scale deployment of CCS would best be initiated by combining geologic sequestration with enhanced oil recovery (EOR), which can use CO2 to improve production from declining oil fields. Revenues from the produced oil could help offset the current high costs of CCS. </p><p>The cumulative potential of CCS-EOR in the continental U.S. has been evaluated in terms of both CO2 storage capacity and additional oil production. This thesis examines the same potential, but on a reservoir-by-reservoir basis. Reservoir properties from the Nehring Oil and Gas Database are used as inputs to a CCS-EOR model developed by McCoy (YR) to estimate the storage capacity, oil production and CCS-EOR costs for over 10,000 oil reservoirs located throughout the continental United States. </p><p>We find that 86% of the reservoirs could store &#8804;1 y or CO2 emissions from a single 500 MW coal-fired power plant (i.e., 3 Mtons CO2). Less than 1% of the reservoirs, on the other hand, appear capable of storing &#8805;30 y of CO2 emissions from a 500 MW plan. But these larger reservoirs are also estimated to contain 48% of the predicted additional oil that could be produced through CCS-EOR. The McCoy model also predicts that the reservoirs will on average produce 4.5 bbl of oil for each ton of sequestered CO2, a ratio known as the utilization factor. This utilization factor is 1.5 times higher that arrived at by the U.S. Department of Energy, and leads to a cumulative production of oil for all the reservoirs examined of ~183 billion barrels along with a cumulative storage capacity of 41 Mtons CO2. This is equivalent to 26.5 y of current oil consumption by the nation, and 8.5 y of current coal plant emissions.</p> / Thesis

Gradient Enhanced Piezoelectric Actuators (GEPAC) are thin piezoelectric plates embedded between two composites layers having different thermal properties. Compared to standard unimorph bending actuators, GEPACs offer superior performances for operations at low frequencies. Potential applications are in the area of multifunctional aircraft skins. In practice, delaminations or debonding within the actuator itself can occur, and it is highly desirable to develop an ultrasonic nondestructive method to monitor the integrity of the actuator in real time. For this study, the composite material is unidirectional Kevlar-epoxy, with fibers oriented at 90 and 0 for the upper and lower layers to achieve different coefficient of thermal expansion. A thin PZT plate is inserted between the two layers, and extended copper foil is used for electrodes on the PZT. The first objective of the research is to demonstrate that, by using segmented electrodes, one can simultaneously launch an ultrasonic pulse (1 MHz) for NDE testing while the actuator is undergoing low frequency actuation (less than 100 Hz). The second objective is to show that the ultrasonic signal can be used to detect damage induced during fatigue testing of the actuator. The third objective is to use the technique to monitor the integrity of a composite plate containing several embedded GEPACs.

Interactive television (iTV) is an umbrella term used to cover the convergence of television with digital media technologies such as computers, personal video recorders, game consoles, and mobile devices, enabling user interactivity. Increasingly, viewers are moving away from a "lean back" model of viewing to a more active "lean forward" one. When fully realized on a widespread scale in the United States, our current experience of watching television will be dramatically transformed. Because iTV is a new medium in its own right, however, standards for iTV programming and interaction in the United States remain undefined. This document identifies and articulates interaction design principles for interactive television programming in the United States. Chapter one presents a brief survey of the field as it stands in 2005. In chapters two and three, I categorize iTV by platforms and by persistent television genres, and present representative examples for each category. In chapter four, I provide an overview of existing design standards in related areas. Insights from chapters two, three, and four all serve to inform chapter five, in which I propose principles for iTV interaction design by looking closely at existing designs (both deployed and prototyped), conventions, and patterns of interaction. My analyses are rooted in visual culture and human-computer interaction design principles, and the design principles I offer are abstracted from the applications I analyze within this framework. Finally, in chapter six, I offer some conclusions and thoughts for future directions.

Carrier dynamics in GaAs-based photoconductive terahertz (THz) sources is investigated using Monte Carlo techniques to optimize the emitted THz transients. A self-consistent Monte Carlo-Poisson solver is developed for the spatio-temporal carrier transport properties. The screening contributions to the THz radiation associated with the Coulomb and radiation fields are obtained self-consistently by incorporating the three-dimensional Maxwell equations into the solver. In addition, the enhancement of THz emission by a large trap-enhance field (TEF) near the anode in semi-insulating (SI) photoconductors is investigated. The transport properties of the photoexcited carriers in photoconductive THz sources depend markedly on the initial spatial distribution of those carriers. Thus, considerable control of the emitted THz spectrum can be attained by judiciously choosing the optical excitation spot shape on the photoconductor, since the carrier dynamics that provide the source of the THz radiation are strongly affected by the ensuing screenings. The screening contributions due to the Coulomb and radiation parts of the electromagnetic field acting back on the carrier dynamics are distinguished. The dominant component of the screening field crosses over at an excitation aperture size with full width at half maximum (FWHM) of ~100 um for a range of reasonable excitation levels. In addition, the key mechanisms responsible for the TEF near the anode of SI photoconductors are elucidated in detail. For a given optical excitation power, an enhancement of THz radiation power can be obtained using a maximally broadened excitation aperture in the TEF area elongated along the anode due to the reduction in the Coulomb and radiation screening of the TEF.