Modeling a Cold Crucible Induction Heated Melter

FIDAP has been used to simulate melting of radioactive waste glass in a cold crucible induction heated melter. A model has been created that couples the magnetic vector potential (real and imaginary) to a transient startup of the melting process. This magnetic field is coupled with mass, momentum, and energy equations that vary with time and position as the melt grows. The coupling occurs with the electrical conductivity of the glass as it rises above the melt temperature of the glass and heat is generated. Natural convection within the molten glass helps determine the shape of the melt as it progresses in time. An electromagnetic force is also implemented that is dependent on the electrical properties and frequency of the coil. This study shows the progression of the melt shape with time along with temperatures, power input, velocities, and magnetic vector potential. A power controller is implemented that controls the primary coil current and power

Single-strand selective monofunctional uracil-DNA glycosylase (SMUG1) deficiency is linked to aggressive breast cancer and predicts response to adjuvant therapy

Uracil in DNA is an important cause of mutagenesis. SMUG1 is a uracil DNA glycosylase that removes uracil through base excision repair. SMUG1 also processes radiation induced oxidative base damage as well as 5-fluorouracil incorporated into DNA during chemotherapy. We investigated SMUG1 mRNA expression in 249 primary breast cancers. SMUG1 protein expression was investigated in 1165 breast tumours randomised into two cohorts [training set (n=583) and test set (n=582)]. SMUG1 and chemotherapy response was also investigated in a series of 315 ER negative tumours (n=315). For mechanistic insights, SMUG1 was correlated to biomarkers of aggressive phenotype, DNA repair, cell cycle and apoptosis. Low SMUG1 mRNA expression was associated with adverse disease specific survival (p=0.008) and disease free survival (p=0.008). Low SMUG1 protein expression (25%) was associated with high histological grade (p<0.0001), high mitotic index (p<0.0001), pleomorphism (p<0.0001), glandular de-differentiation (p=0.0001), absence of hormonal receptors (ER-/PgR-/AR) (p<0.0001), presence of basal-like (p<0.0001) and triple negative phenotypes (p<0.0001). Low SMUG1 protein expression was associated with loss of BRCA1 (p<0.0001), ATM (p<0.0001) and XRCC1 (p<0.0001). Low p27 (p<0.0001), low p21 (p=0.023), mutant p53 (p=0.037), low MDM2 (p<0.0001), low MDM4 (p=0.004), low Bcl-2 (p=0.001), low Bax (p=0.003) and high MIB1 (p<0.0001) were likely in low SMUG1 tumours. Low SMUG1 protein expression was associated with poor prognosis in univariate (p<0.001) and multivariate analysis (p<0.01). In ER+ cohort that received adjuvant endocrine therapy, low SMUG1 protein expression remains associated with poor survival (p<0.01). In ER- cohort that received adjuvant chemotherapy, low SMUG1 protein expression is associated with improved survival (p=0.043). Our study suggests that low SMUG1 expression may correlate to adverse clinicopathological features and predict response to adjuvant therapy in breast cancer

Assessing the importance of Isle of Man waters for the basking shark Cetorhinus maximus

This is the final version. Available on open access from Inter Research via the DOI in this recordSatellite tracking of endangered or threatened animals can facilitate informed conservation by revealing priority areas for their protection. Basking sharks (Cetorhinus maximus, n=11) were tagged during the summers of 2013, 2015, 2016 and 2017 in the Isle of Man (IoM; median tracking duration 378 days (range: 89-804 days); median minimum straight-line distance travelled 541 km (range: 170-10,406 km). Tracking revealed three movement patterns: (i) coastal movements within IoM and Irish waters, (ii) summer northward movements to Scotland and Norway and (iii) international movements to Morocco and Norway. One tagged shark was bycaught and released alive in the Celtic Sea. Basking sharks displayed inter-annual site fidelity to the Irish Sea (n=3), a Marine Nature Reserve (MNR) in IoM waters (n=1), and Moroccan waters (n=1). Core distribution areas (50% kernel density estimation) of five satellite tracked sharks in IoM waters were compared with 3,902 public sightings between 2005 and 2017, highlighting West and South coast hotspots. Location data gathered from satellite tagging broadly corresponds to the current boundaries of MNRs in Manx waters. However, minor modifications of some MNR boundaries would incorporate ~20% more satellite tracking location data from this study, and protective measures for basking sharks in IoM waters could further aid conservation of the species at a local, regional and international scale. We also show the first documented movement of a basking shark from the British Isles to Norway, and the longest ever track for a tagged basking shark (two years and two months, 804 days)

An inter-model assessment of the role of direct air capture in deep mitigation pathways

The feasibility of large-scale biological CO2 removal to achieve stringent climate targets remains unclear. Direct Air Carbon Capture and Storage (DACCS) offers an alternative negative emissions technology (NET) option. Here we conduct the first inter-model comparison on the role of DACCS in 1.5 and 2°C scenarios, under a variety of techno-economic assumptions. Deploying DACCS significantly reduces mitigation costs, and it complements rather than substitutes other NETs. The key factor limiting DACCS deployment is the rate at which it can be scaled up. Our scenarios’ average DACCS scale-up rates of 1.5 GtCO2/yr would require considerable sorbent production and up to 300 EJ/yr of energy input by 2100. The risk of assuming that DACCS can be deployed at scale, and finding it to be subsequently unavailable, leads to a global temperature overshoot of up to 0.8°C. DACCS should therefore be developed and deployed alongside, rather than instead of, other mitigation options

On the criticality of inferred models

Advanced inference techniques allow one to reconstruct the pattern of interaction from high dimensional data sets. We focus here on the statistical properties of inferred models and argue that inference procedures are likely to yield models which are close to a phase transition. On one side, we show that the reparameterization invariant metrics in the space of probability distributions of these models (the Fisher Information) is directly related to the model's susceptibility. As a result, distinguishable models tend to accumulate close to critical points, where the susceptibility diverges in infinite systems. On the other, this region is the one where the estimate of inferred parameters is most stable. In order to illustrate these points, we discuss inference of interacting point processes with application to financial data and show that sensible choices of observation time-scales naturally yield models which are close to criticality.Comment: 6 pages, 2 figures, version to appear in JSTA

Design of a compact heat exchanger for heat recuperation from a high temperature electrolysis system

Design details of a compact heat exchanger and supporting hardware for heat recuperation in a high-temperature electrolysis application are presented. The recuperative heat exchanger uses a vacuum-brazed plate-fin design and operates between 300 and 800°C. It includes corrugated inserts for enhancement of heat transfer coefficients and extended heat transfer surface area. Two recuperative heat exchangers are required per each four-stack electrolysis module. The heat exchangers are mated to a base manifold unit that distributes the inlet and outlet flows to and from the four electrolysis stacks. Results of heat exchanger design calculations and assembly details are also presented

THE PRODUCTION OF SYNGAS VIA HIGH TEMPERATURE ELECTROLYSIS AND BIO-MASS GASIFICATION

A process model of syngas production using high temperature electrolysis and biomass gasification is presented. Process heat from the biomass gasifier is used to improve the hydrogen production efficiency of the steam electrolysis process. Hydrogen from electrolysis allows a high utilization of the biomass carbon for syngas production. Based on the gasifier temperature, 94% to 95% of the carbon in the biomass becomes carbon monoxide in the syngas (carbon dioxide and hydrogen). Assuming the thermal efficiency of the power cycle for electricity generation is 50%, (as expected from GEN IV nuclear reactors), the syngas production efficiency ranges from 70% to 73% as the gasifier temperature decreases from 1900 K to 1500 K

Communities in university mathematics

This paper concerns communities of learners and teachers that are formed, develop and interact in university mathematics environments through the theoretical lens of Communities of Practice. From this perspective, learning is described as a process of participation and reification in a community in which individuals belong and form their identity through engagement, imagination and alignment. In addition, when inquiry is considered as a fundamental mode of participation, through critical alignment, the community becomes a Community of Inquiry. We discuss these theoretical underpinnings with examples of their application in research in university mathematics education and, in more detail, in two Research Cases which focus on mathematics students' and teachers' perspectives on proof and on engineering students' conceptual understanding of mathematics. The paper concludes with a critical reflection on the theorising of the role of communities in university level teaching and learning and a consideration of ways forward for future research

Epigenetic patterns newly established after interspecific hybridization in natural populations of Solanum

Interspecific hybridization is known for triggering genetic and epigenetic changes, such as modifications on DNA methylation patterns and impact on phenotypic plasticity and ecological adaptation. Wild potatoes (Solanum, section Petota) are adapted to multiple habitats along the Andes, and natural hybridizations have proven to be a common feature among species of this group. Solanum × rechei, a recently formed hybrid that grows sympatrically with the parental species S. kurtzianum and S. microdontum, represents an ideal model for studying the ecologically and evolutionary importance of hybridization in generating of epigenetic variability. Genetic and epigenetic variability and their correlation with morphological variation were investigated in wild and ex situ conserved populations of these three wild potato species using amplified fragment length polymorphism (AFLP) and methylation‐sensitive amplified polymorphism (MSAP) techniques. We observed that novel methylation patterns doubled the number of novel genetic patterns in the hybrid and that the morphological variability measured on 30 characters had a higher correlation with the epigenetic than with the genetic variability. Statistical comparison of methylation levels suggested that the interspecific hybridization induces genome demethylation in the hybrids. A Bayesian analysis of the genetic data reveled the hybrid nature of S. × rechei, with genotypes displaying high levels of admixture with the parental species, while the epigenetic information assigned S. × rechei to its own cluster with low admixture. These findings suggested that after the hybridization event, a novel epigenetic pattern was rapidly established, which might influence the phenotypic plasticity and adaptation of the hybrid to new environments.EEA La ConsultaFil: Cara, Nicolás. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Mendoza. Instituto de Biologia Agricola de Mendoza; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Instituto de Biologia Agricola de Mendoza; ArgentinaFil: Marfil, Carlos Federico. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Mendoza. Instituto de Biologia Agricola de Mendoza; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Instituto de Biologia Agricola de Mendoza; ArgentinaFil: Masuelli, Ricardo Williams. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria La Consulta; Argentin