The design and development of hydrogen isotope extraction technologies for a limit-style liquid lithium loop

As lithium has grown in popularity as a plasma-facing material, efforts have been placed on examining its viability as a first wall candidate. Lithium has proven over numerous studies to improve core confinement, while allowing access to operational regimes previously unattainable while using solid, high-Z divertor and limiter modules. These benefits are due to the fuel retention capabilities of lithium, which allow it to be an almost ideally absorbing boundary, which is both beneficial and problematic. While lithium exhibits a number of other advantages and disadvantages as a plasma-facing material, none is more important than the tritium retention problem. As such, extraction technologies must be constructed and verified within the scope of larger scale lithium loop systems that separate lithium impurities, recover deuterium and tritium, and recycle clean liquid lithium back to the plasma-material interface. Laboratory-scale and pilot-scale studies have been conducted at the Center for Plasma-Material Interactions at the University of Illinois to investigate a number of phenomena that influence the recovery of entrained tritium from lithium. While the ultimate goal is to develop a fully-functional liquid lithium loop for the Lithium Metal Infused Trenches plasma-facing component, complete with efficient hydrogen reclamation technologies, there exists a lack in understanding within the community of the thermochemical fundamentals that are envisioned to drive tritium reclamation. Of specific interest are the evolution fluxes of hydrogen isotopes from solutions of various concentrations of hydrogen in lithium, and the associated temperatures. The knowledge of how the isotopic fraction affects recovery is pivotal to determining the appropriate thermal treatment technique. The laboratory-scale experiments in this report aimed at filling in the knowledge gaps in the literature with regards to the thermochemistry of the hydrogen-lithium system. In all cases, hydrogen was used as an isotopic surrogate for deuterium and tritium. Success was based on an individual samples ability to evolve molecular hydrogen at rates that would match or exceed in-vessel wall losses, determined from a simulated Lithium-Walled International Thermonuclear Experimental Reactor scenario. The hydrogen degassing of pure lithium hydride was observed to exceed fuel loss by a factor of two or greater, at temperatures near the melting point for hydride. Samples of both solid and liquid lithium were subjected to different hydrogen environments under a variety of exposure conditions. During plasma exposures, evidence of saturation, where hydride layers are formed at or near the sample surface and inhibit hydrogen absorption, was witnessed for solid lithium samples. Liquid samples exhibited this behavior to a lesser degree; however, mass diffusion was able to transport the insulating species away from the surface and absorption was able to continue, albeit to a lesser extent than was initially detected. The sub-surface chemistry was found to still be limited by the thermodynamic solubility thresholds in a plasma environment, meaning enhanced hydrogen dissolution was not witnessed at ion energies relevant to these experiments. The presence of a plasma, however, did appear to enhance absorption rates above and beyond what was capable with hydrogen gas alone. During these tests, hydrogen evolution rates from the dissolved phase never approached the point of being able to balance losses at the plasma-material interface, being always less by a factor of two or more. It was therefore determined that supplementary methods were required to enhance thermal-based recovery in solutions with hydrogen molar ratios less than the solubility limits. This work culminated in the design, development, construction, and proof-of-concept testing of a distillation column. Envisioned to be an integrated treatment method in a fully functional lithium loop, the column was developed based on the need to recover tritium and recycle fresh lithium back into the reactor. The novelty in this design was in its use of induction heating drive and condensation stages. Proof-of-concept tests were performed in the fully constructed prototype with solutions of lithium and lithium hydride at various molar ratios. The system was observed to operate as intended during these initial runs, but requires further testing; however, the column marks the first system constructed for the sole purpose of recovering tritium from a lithium-walled reactor. Such a system will prove most effective if upstream separation and purification techniques are present to divert the lithium deuteride and lithium tritide-rich streams to the column for thermal decomposition and degassing. In the case where upstream purification modules are absent from the lithium loop, the column alone will be hard pressed to achieve recovery rates in far-from-saturated solutions that balance wall losses. A technique to supplement the induction heating drive was therefore proposed. Ultrasonic degassing of liquid metals is an industry-tested technique used to rid melts of dissolved gases by taking advantage of acoustically-induced cavitation. This process was theoretically applied to the hydrogen-lithium system, displaying evidence that degassing is most effective in the presence of heat, ultrasonic waves, and vacuum. This work laid the theoretical groundwork for future application. The results presented in this report show that using the appropriate combination of treatment methods, hydrogen, and by extension deuterium and tritum, can be recovered from lithium at rates that balance in-vessel wall loss. Future work will be needed to then integrate these methods into a fully functional liquid lithium loop

Characterization of ion properties in a linear pulsed plasma-material interaction test stand

In the edge and divertor regions of the magnetically confined plasma, tokamaks experience off-normal events in which high intensities of heat flux incident on wall component surfaces result in intolerable levels of damage. Proposed solid divertors will not be able to withstand these fluxes, especially in larger toroidal machines such as ITER and DEMO. In addition to this detrimental effect on solid wall materials, demonstrations have shown that the erosion of these materials can cause impurity generation and transport within the bulk plasma, leading to high radiative losses. To avoid these and other major issues, liquid metal divertor and wall schemes have been proposed and studies have been done to understand their effect on bulk tokamak plasmas. To simulate extreme events in the tokamak boundary and provide a test stand for liquid-metal plasma-facing components, a pulsed plasma source utilizing a theta pinch in conjunction with a coaxial plasma accelerator has been developed[1-3]. The ThermoElectric-driven Liquid-metal plasma-facing Structures (TELS) device will provide fusion-relevant plasma flux incident on structures with flowing liquid metal surfaces. In order to accurately quantify the ability of TELS to provide a simulated disruption or edge localized mode (ELM) plasma, a suite of diagnostics was used to measure a variety of plasma parameters. The objective of this thesis was to develop an electrostatic analyzer to measure the ion information in TELS and use the results to understand particle energy distribution and loss as a function of distance from the plasma source. It has been previously observed that TELS plasmas can bombard a target with an electron density of 3 x 1021 m-3, an electron temperature of 20 to 30 eV, and a peak energy flux of 0.08 MJ/m2 over the pulse length of 100 to 200 µs[2]. To validate that the experimentally observed heat flux delivered to a target corresponds to the isotropic magnetohydrodynamic (MHD) predictions based on electron and ion temperatures, it became necessary to evaluate the ion temperature and subsequent energy distribution. In addition to these theoretical comparisons, the ion temperature and transport of ions down the length of the chamber is important in order to fully characterize a system that preferentially heats and accelerates ions as a function of the energy coupling in the theta pinch. Two major conditions were imposed to observe how ions behave as a function of the effect of the compression with the theta pinch. First, the analyzer system comprised of an analyzer open to the plasma and an analyzer closed to the plasma was inserted into the target chamber, at a distance of 16 inches (40.6 cm) downstream of the theta pinch. The closed analyzer was used as an experimental control, so that the effects of electromagnetic and circuit noise were eliminated from the open analyzer signal. The ion current showed two prominent features that followed in suit with the way the PiP discharges, and the time-averaged temperatures were taken with respect to the duration of these features during the pulse. Without guiding magnetic fields used to prevent ion diffusive losses, the measured ion signal showed an ion temperature of 22.83 ± 7.43 eV for the first peak and 17.59 ± 11.53 eV for the second peak. This measurement was used as a basis against which to compare ion temperatures subject to different pulse conditions. Secondly, the analyzer system measured the ion information from the use of only the coaxial plasma accelerator as a comparison by which the theta pinch can be proven effective or not. Without the use of guiding fields, the measured signal showed an ion temperature of 10.40 ± 6.62 eV for the first peak and 7.70 ± 3.57 eV for the second peak. The effects of these results from a plasma transport and a plasma-material interaction basis will be discussed

Working hard on the outside: a multimodal critical discourse analysis of The Biggest Loser Australia

The Biggest Loser (TBL) is a reality television weight-loss programme that positions itself as a response to the so-called “obesity crisis”. Research on TBL has thus far focussed on audience responses and its effect on viewers’ beliefs about weight loss. This article focuses instead on how meaning is constructed in TBL. We conducted a multimodal critical discourse analysis of a key episode of TBL (the 2012 Australian season finale) to examine how the textual, visual and auditory elements combine to construct meanings beyond the ostensible health messages. Although the overt message is that all contestants have worked hard, turned their lives around and been “successful”, examination of editing choices, lighting and colour, clothing and time spent on contestants allows us to see that the programme constructs varying degrees of success between contestants and provides accounts for these differences in outcomes. In this way the programme is able to present itself as a putative celebration of all contestants while prescribing narrow limits around what constitutes success. TBL reinforces an ideology in which “success” is a direct result of “the work” of weight loss (both physical and emotional), which can apparently be read straightforwardly off the body. TBL’s “celebration” of weight loss thus reproduces and strengthens the widespread view of fat bodies as physical manifestations of individual (ir)responsibility and psychological dysfunction, and contributes to the ongoing stigmatisation of obesity

Rationale and Design of the ICON-RELOADED Study: International Collaborative of Nterminal pro-B-type Natriuretic Peptide Re-evaluation of Acute Diagnostic Cut-Offs in the Emergency Department

Objectives The objectives were to reassess use of amino-terminal pro B-type natriuretic peptide (NT-proBNP) concentrations for diagnosis and prognosis of acute heart failure (HF) in patients with acute dyspnea. Background NT-proBNP facilitates diagnosis, prognosis, and treatment in patients with suspected or proven acute HF. As demographics of such patients are changing, previous diagnostic NT-proBNP thresholds may need updating. Additionally, value of in-hospital NT-proBNP prognostic monitoring for HF is less understood. Methods In a prospective, multicenter study in the United States and Canada, patients presenting to emergency departments with acute dyspnea were enrolled, with demographic, medication, imaging, and clinical course information collected. NT-proBNP analysis will be performed using the Roche Diagnostics Elecsys proBNPII immunoassay in blood samples obtained at baseline and at discharge (if hospitalized). Primary end points include positive predictive value of previously established age-stratified NT-proBNP thresholds for the adjudicated diagnosis of acute HF and its negative predictive value to exclude acute HF. Secondary end points include sensitivity, specificity, and positive and negative likelihood ratios for acute HF and, among those with HF, the prognostic value of baseline and predischarge NT-proBNP for adjudicated clinical end points (including all-cause death and hospitalization) at 30 and 180 days. Results A total of 1,461 dyspneic subjects have been enrolled and are eligible for analysis. Follow-up for clinical outcome is ongoing. Conclusions The International Collaborative of N-terminal pro–B-type Natriuretic Peptide Re-evaluation of Acute Diagnostic Cut-Offs in the Emergency Department study offers a contemporary opportunity to understand best diagnostic cutoff points for NT-proBNP in acute HF and validate in-hospital monitoring of HF using NT-proBNP

Multicenter Evaluation of a 0-Hour/1-Hour Algorithm in the Diagnosis of Myocardial Infarction With High-Sensitivity Cardiac Troponin T

Study objectiveWe aim to prospectively validate the diagnostic accuracy of the recently developed 0-h/1-h algorithm, using high-sensitivity cardiac troponin T (hs-cTnT) for the early rule-out and rule-in of acute myocardial infarction.MethodsWe enrolled patients presenting with suspected acute myocardial infarction and recent (<6 hours) onset of symptoms to the emergency department in a global multicenter diagnostic study. Hs-cTnT (Roche Diagnostics) and sensitive cardiac troponin I (Siemens Healthcare) were measured at presentation and after 1 hour, 2 hours, and 4 to 14 hours in a central laboratory. Patient triage according to the predefined hs-cTnT 0-hour/1-hour algorithm (hs-cTnT below 12 ng/L and Δ1 hour below 3 ng/L to rule out; hs-cTnT at least 52 ng/L or Δ1 hour at least 5 ng/L to rule in; remaining patients to the “observational zone”) was compared against a centrally adjudicated final diagnosis by 2 independent cardiologists (reference standard). The final diagnosis was based on all available information, including coronary angiography and echocardiography results, follow-up data, and serial measurements of sensitive cardiac troponin I, whereas adjudicators remained blinded to hs-cTnT.ResultsAmong 1,282 patients enrolled, acute myocardial infarction was the final diagnosis for 213 (16.6%) patients. Applying the hs-cTnT 0-hour/1-hour algorithm, 813 (63.4%) patients were classified as rule out, 184 (14.4%) were classified as rule in, and 285 (22.2%) were triaged to the observational zone. This resulted in a negative predictive value and sensitivity for acute myocardial infarction of 99.1% (95% confidence interval [CI] 98.2% to 99.7%) and 96.7% (95% CI 93.4% to 98.7%) in the rule-out zone (7 patients with false-negative results), a positive predictive value and specificity for acute myocardial infarction of 77.2% (95% CI 70.4% to 83.0%) and 96.1% (95% CI 94.7% to 97.2%) in the rule-in zone, and a prevalence of acute myocardial infarction of 22.5% in the observational zone.ConclusionThe hs-cTnT 0-hour/1-hour algorithm performs well for early rule-out and rule-in of acute myocardial infarction

Common Genetic Polymorphisms Influence Blood Biomarker Measurements in COPD

Implementing precision medicine for complex diseases such as chronic obstructive lung disease (COPD) will require extensive use of biomarkers and an in-depth understanding of how genetic, epigenetic, and environmental variations contribute to phenotypic diversity and disease progression. A meta-analysis from two large cohorts of current and former smokers with and without COPD [SPIROMICS (N = 750); COPDGene (N = 590)] was used to identify single nucleotide polymorphisms (SNPs) associated with measurement of 88 blood proteins (protein quantitative trait loci; pQTLs). PQTLs consistently replicated between the two cohorts. Features of pQTLs were compared to previously reported expression QTLs (eQTLs). Inference of causal relations of pQTL genotypes, biomarker measurements, and four clinical COPD phenotypes (airflow obstruction, emphysema, exacerbation history, and chronic bronchitis) were explored using conditional independence tests. We identified 527 highly significant (p 10% of measured variation in 13 protein biomarkers, with a single SNP (rs7041; p = 10^−392) explaining 71%-75% of the measured variation in vitamin D binding protein (gene = GC). Some of these pQTLs [e.g., pQTLs for VDBP, sRAGE (gene = AGER), surfactant protein D (gene = SFTPD), and TNFRSF10C] have been previously associated with COPD phenotypes. Most pQTLs were local (cis), but distant (trans) pQTL SNPs in the ABO blood group locus were the top pQTL SNPs for five proteins. The inclusion of pQTL SNPs improved the clinical predictive value for the established association of sRAGE and emphysema, and the explanation of variance (R2) for emphysema improved from 0.3 to 0.4 when the pQTL SNP was included in the model along with clinical covariates. Causal modeling provided insight into specific pQTL-disease relationships for airflow obstruction and emphysema. In conclusion, given the frequency of highly significant local pQTLs, the large amount of variance potentially explained by pQTL, and the differences observed between pQTLs and eQTLs SNPs, we recommend that protein biomarker-disease association studies take into account the potential effect of common local SNPs and that pQTLs be integrated along with eQTLs to uncover disease mechanisms. Large-scale blood biomarker studies would also benefit from close attention to the ABO blood group

Common Genetic Polymorphisms Influence Blood Biomarker Measurements in COPD

Implementing precision medicine for complex diseases such as chronic obstructive lung disease (COPD) will require extensive use of biomarkers and an in-depth understanding of how genetic, epigenetic, and environmental variations contribute to phenotypic diversity and disease progression. A meta-analysis from two large cohorts of current and former smokers with and without COPD [SPIROMICS (N = 750); COPDGene (N = 590)] was used to identify single nucleotide polymorphisms (SNPs) associated with measurement of 88 blood proteins (protein quantitative trait loci; pQTLs). PQTLs consistently replicated between the two cohorts. Features of pQTLs were compared to previously reported expression QTLs (eQTLs). Inference of causal relations of pQTL genotypes, biomarker measurements, and four clinical COPD phenotypes (airflow obstruction, emphysema, exacerbation history, and chronic bronchitis) were explored using conditional independence tests. We identified 527 highly significant (p 10% of measured variation in 13 protein biomarkers, with a single SNP (rs7041; p = 10−392) explaining 71%-75% of the measured variation in vitamin D binding protein (gene = GC). Some of these pQTLs [e.g., pQTLs for VDBP, sRAGE (gene = AGER), surfactant protein D (gene = SFTPD), and TNFRSF10C] have been previously associated with COPD phenotypes. Most pQTLs were local (cis), but distant (trans) pQTL SNPs in the ABO blood group locus were the top pQTL SNPs for five proteins. The inclusion of pQTL SNPs improved the clinical predictive value for the established association of sRAGE and emphysema, and the explanation of variance (R2) for emphysema improved from 0.3 to 0.4 when the pQTL SNP was included in the model along with clinical covariates. Causal modeling provided insight into specific pQTL-disease relationships for airflow obstruction and emphysema. In conclusion, given the frequency of highly significant local pQTLs, the large amount of variance potentially explained by pQTL, and the differences observed between pQTLs and eQTLs SNPs, we recommend that protein biomarker-disease association studies take into account the potential effect of common local SNPs and that pQTLs be integrated along with eQTLs to uncover disease mechanisms. Large-scale blood biomarker studies would also benefit from close attention to the ABO blood group

Burden of Uncontrolled Severe Asthma With and Without Elevated Type-2 Inflammatory Biomarkers

Background: Many patients with asthma have type-2 airway inflammation, identified by the presence of biomarkers, including history of allergy, high blood eosinophil (EOS) count, and high fractional exhaled nitric oxide levels. Objective: To assess disease burden in relation to type-2 inflammatory biomarker status (history of allergy, blood EOS count, and fractional exhaled nitric oxide level) in patients with uncontrolled and controlled severe asthma in the NOVEL observational longiTudinal studY (NOVELTY) (NCT02760329). Methods: Asthma diagnosis and severity were physician-reported. Control was defined using Asthma Control Test score (uncontrolled = 20) and/or 1 or more severe physician-reported exacerbation in the previous year. Biomarker distribution (history of allergy, blood EOS count, and fractional exhaled nitric oxide level), symptom burden (Asthma Control Test score, modified Medical Research Council dyspnea scale), health status (St George's Respiratory Questionnaire score), exacerbations, and health care resource utilization were assessed. Results: Of 647 patients with severe asthma, 446 had uncontrolled and 123 had controlled asthma. Among those with uncontrolled asthma, 196 (44%) had 2 or more positive biomarkers, 187 (42%) had 1 positive biomarker, 325 (73%) had low blood EOS, and 63 (14%) were triple-negative. Disease burden was similarly high across uncontrolled subgroups, irrespective of biomarker status, with poor symptom control (Asthma Control Test score 14.9-16.6), impaired health status (St George's Respiratory Questionnaire total score 46.7-49.4), clinically important breathlessness (modified Medical Research Council grade >= 2 in 47.3%-57.1%), and 1 or more severe exacerbation (70.6%-76.2%). Conclusions: Type-2 inflammatory biomarkers did not differentiate disease burden in patients with severe asthma. Patients with low type-2 inflammatory biomarker levels have few biologic therapy options; their needs should be addressed

Voice to Vision VI: Scattering of Pears

University of Minnesota Center for Holocaust and Genocide Studies. University of Minnesota Department of Art.University of Minnesota: Undergraduate Research Opportunities Program (UROP), CLA Freshman Research and Creative Awards Program, Imagine GrantFeinberg, David; Vidovic, Dragana; Lommen, Peter; Charbonneau, Chris; Christenson, Joni; Giles, Daisy; Hiatt, Sarah; Pope, Rowan; Rodriguez, Nicole; Zittlow, Michael; Jokondo, Daliya. (2011). Voice to Vision VI: Scattering of Pears. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/167948