The power threshold of H-mode access in mixed hydrogen–tritium and pure tritium plasmas at JET with ITER-like wall

The heating power to access the high confinement mode (H-mode), PLH, scales approximately inversely with the isotope mass of the main ion plasma species as found in (protonic) hydrogen, deuterium and tritium plasmas in many fusion facilities over the last decades. In first dedicated L–H transition experiments at the Joint European Torus (JET) tokamak facility with the ITER-like wall (ILW), the power threshold, PLH, was studied systematically in plasmas of pure tritium and hydrogen–tritium mixtures at a magnetic field of 1.8 T and a plasma current of 1.7 MA in order to assess whether this scaling still holds in a metallic wall device. The measured power thresholds, PLH, in Ohmically heated tritium plasmas agree well with the expected isotope scaling for metallic walls and the lowest power threshold was found in Ohmic phases at low density. The measured power thresholds in ion cyclotron heated plasmas of pure tritium or hydrogen–tritium mixtures are significantly higher than the expected isotope mass scaling due to higher radiation levels. However, when the radiated power is taken into account, the ion cyclotron heated plasmas exhibit similar power thresholds as a neutral beam heated plasma, and are close to the scaling. The tritium plasmas in this study tended to higher electron heating fractions and, when heated with ion cyclotron waves, to relatively higher radiation fractions compared to other isotopes potentially impeding access to sustained H-modes.The authors thank P.A. Schneider, F. Ryter, A. Nielsen, and A. Kappatou for fruitful discussions and for help with data analysis tools. This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom Research and Training Programme 2014–2018 and 2019–2020 under Grant Agreement No. 633053. The views and opinions expressed herein do not necessarily reflect those of the European Commission. G. Birkenmeier received funding from the Helmholtz Association under Grant No. VH-NG-1350.Peer Reviewed"Article signat per 27 autors/es: G. Birkenmeier, E.R. Solano, E. Lerche, D. Taylor, D. Gallart, M.J. Mantsinen, E. Delabie, I.S. Carvalho, P. Carvalho, E. Pawelec, J.C. Hillesheim, F. Parra Diaz, C. Silva, S. Aleiferis, J. Bernardo, A. Boboc, D. Douai, E. Litherland-Smith, R. Henriques, K.K. Kirov, C.F. Maggi, J. Mailloux, M. Maslov, F.G. Rimini, S.A. Silburn, P. Sirén, H. Weisen and JET Contributors"Postprint (published version

Effect of inclusion of pitch-angle dependence on a simplified model of RF deposition in tokamak plasma

Using the PION ICRH modelling code and comparisons against JET tokamak experiments, the effect of including pitch angle dependence within the RF diffusion operator on the fast ion particle distribution functions is quantified. It is found to be of greatest importance in cases of higher harmonic heating and lower heating ion mass, resulting in faster drop-off of the distribution's high energy tail. We see differences of several orders of magnitude in the high-energy range and significant non-linear alterations by several tens of percent to ion species power partition. ITER scenario operational parameters are also considered, and this improved treatment is shown to benefit anticipated ITER scenarios with second harmonic hydrogen heating, according to our predictions. PION's combination of benchmarked simplified wave physics and Fokker-Planck treatment offers modelling advantages. Since including the pitch angle dependence in the RF diffusion operator has not led to a significant increase in the required computing time when modelling different ICRF schemes in JET discharges, it has been made available within the production code.The CCFE part of this work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training programme 2014–2018 and 2019–2020 under Grant Agreement No. 633053. The views and opinions expressed herein do not necessarily reflect those of the European Commission. The BSC part of this project is co-financed by the European Union Regional Development Fund within the framework of the ERDF Operational Program of Catalonia 2014–2020 with a grant of 50% of total cost eligible. The authors are grateful to Jacob Eriksson for assistance with experimental data, to Lars-Göran Eriksson for discussions on the implementation of the new features, and to Colin Roach and Michael Fitzgerald for valuable comments on the manuscript.Peer ReviewedPostprint (published version

splot - visual analytics for spatial statistics

We closed a total of 15 issues (enhancements and bug fixes) through 6 pull requests, since our last release on 2020-01-18. Issues Closed add permanent links to current version of no's to joss paper (#102) [BUG] set colors as list in _plot_choropleth_fig() (#101) Remove the links around figures in the JOSS paper (#99) Release prep for 1.1.2 (#98) Installation instructions; pip install fails on macOS (#88) Usage in readme is a fragment (#90) JOSS: missing figure captions (#92) [DOC] update installation instruction (#96) [DOC] add example links to README.md & figure captions in joss article (#97) Pull Requests add permanent links to current version of no's to joss paper (#102) [BUG] set colors as list in _plot_choropleth_fig() (#101) Remove the links around figures in the JOSS paper (#99) Release prep for 1.1.2 (#98) [DOC] update installation instruction (#96) [DOC] add example links to README.md & figure captions in joss article (#97) The following individuals contributed to this release: Stefanie Lumnitz Levi John Wolf Leonardo Uieda Serge ReyJoss paper releas

MODELING STEAM DRYERS

ABSTRACT Nuclear steam dryers are used to reduce the moisture carryover (MCO) to levels often well below 0.1%, by weight, water in the steam. The dryers are designed to provide very high quality steam at the full capacity of the steam generator. The purpose of this paper is to present computational fluid dynamics (CFD) models of the steam flow in a generator and the decisions that are required to evaluate different designs. These computational models are successful and proven in field operations

Understanding Campus Environmental Sustainability: A Thematic Analysis of Interviews with Facilities Management Staff and Administrators at the University of Denver

This project sought to understand what influences sustainability choices on the University of Denver campus. Universities and colleges play a pivotal and influential role in shaping sustainable future discourse in society. As centers for innovation and research, universities continue to generate new knowledge and skills necessary to create awareness of the negative impact of human activities on the environment and pathways to mitigate these impacts. Over the past decades, there has been a growing transformation of universities from places of knowledge creation to places where created knowledge is implemented. Thus, in the field of environmental change, there is a growing movement to transition universities from passive creators of knowledge of sustainability to models of sustainability

The Brazilian Tunable Filter Imager for the SOAR telescope

This paper presents a new Tunable Filter Instrument for the SOAR telescope. The Brazilian Tunable Filter Imager (BTFI) is a versatile, new technology, tunable optical imager to be used in seeing-limited mode and at higher spatial fidelity using the SAM Ground-Layer Adaptive Optics facility at the SOAR telescope. The instrument opens important new science capabilities for the SOAR community, from studies of the centers of nearby galaxies and the insterstellar medium to statistical cosmological investigations. The BTFI takes advantage of three new technologies. The imaging Bragg Tunable Filter concept utilizes Volume Phase Holographic Gratings in a double-pass configuration, as a tunable filter, while a new Fabry-Perot (FP) concept involves technologies which allow a single FP etalon to act over a large range of interference orders and spectral resolutions. Both technologies will be in the same instrument. Spectral resolutions spanning the range between 25 and 30,000 can be achieved through the use of iBTF at low resolution and scanning FPs beyond R ~2,000. The third new technologies in BTFI is the use of EMCCDs for rapid and cyclically wavelength scanning thus mitigating the damaging effect of atmospheric variability through data acquisition. An additional important feature of the instrument is that it has two optical channels which allow for the simultaneous recording of the narrow-band, filtered image with the remaining (complementary) broad-band light. This avoids the uncertainties inherent in tunable filter imaging using a single detector. The system was designed to supply tunable filter imaging with a field-of-view of 3 arcmin on a side, sampled at 0.12" for direct Nasmyth seeing-limited area spectroscopy and for SAM's visitor instrument port for GLAO-fed area spectroscopy. The instrument has seen first light, as a SOAR visitor instrument. It is now in comissioning phase.Comment: accepted in PAS

Continuous positive airway pressure therapy effects on lipid and hepatic function test values

Introduction : Continuous positive airway pressure (CPAP) therapy is an established therapy for patients diagnosed with obstructive sleep apnea (OSA). The following study aims to measure the impact of CPAP therapy on lipid and liver profiles of patients diagnosed with OSA. We hypothesize that CPAP therapy will improve patient serum lipid and liver measures in this patient population compared to patient baseline prior to CPAP therapy. Furthermore, we also will examine differences in hepatic ultrasound results for OSA patients on CPAP therapy. Methods: The target patient population has moderate-severe OSA, defined as an Apnea-Hypopnea Index greater than 15. The intervention is defined as a minimum of four hours of CPAP therapy use nightly on average. For lipid panel outcomes, we recorded high density lipoprotein cholesterol (HDL), low density lipoprotein cholesterol (LDL), total cholesterol (TC), and triglycerides (TG). For liver panel outcomes, we measured aspartate aminotransferase (AST) and alanine aminotransferase (ALT) values. All values were compared to each patients’ averaged baseline values six months prior to initiation of CPAP therapy. Furthermore, we also examined hepatic ultrasound results prior to and after beginning CPAP therapy. Results: Data collection is currently ongoing. We expect preliminary data of ten chart reviews of eligible subjects show lower HDL, LDL, TC, TG, AST, and ALT on lipid and liver function tests after consistent CPAP use compared to baseline. Unfortunately, due to this initial small pilot sample size, no significant findings with regard to hepatic ultrasound results have been observed. Discussion: Our results demonstrate that consistent CPAP therapy use helps to lower liver function and lipid tests. This provides support that CPAP therapy, in conjunction with treating OSA, may help to improve outcome values for patients with hypertriglyceridemia and poor liver function. We will continue to collect data on a much larger sample of patients to adequately test our study hypothesis regarding the effects of CPAP therapy effects on hepatic outcomes, such as liver failure, which would provide further support of the beneficial effects of CPAP therapy on vulnerable populations

The Making of a Compound Inflorescence in Tomato and Related Nightshades

Variation in the branching of plant inflorescences determines flower number and, consequently, reproductive success and crop yield. Nightshade (Solanaceae) species are models for a widespread, yet poorly understood, program of eudicot growth, where short side branches are initiated upon floral termination. This “sympodial” program produces the few-flowered tomato inflorescence, but the classical mutants compound inflorescence (s) and anantha (an) are highly branched, and s bears hundreds of flowers. Here we show that S and AN, which encode a homeobox transcription factor and an F-box protein, respectively, control inflorescence architecture by promoting successive stages in the progression of an inflorescence meristem to floral specification. S and AN are sequentially expressed during this gradual phase transition, and the loss of either gene delays flower formation, resulting in additional branching. Independently arisen alleles of s account for inflorescence variation among domesticated tomatoes, and an stimulates branching in pepper plants that normally have solitary flowers. Our results suggest that variation of Solanaceae inflorescences is modulated through temporal changes in the acquisition of floral fate, providing a flexible evolutionary mechanism to elaborate sympodial inflorescence shoots

Long-Term Soil Structure Observatory for Monitoring Post-Compaction Evolution of Soil Structure

The projected intensification of agriculture to meet food targets of a rapidly growing world population are likely to accentuate already acute problems of soil compaction and deteriorating soil structure in many regions of the world. The key role of soil structure for soil functions, the sensitivity of soil structure to agronomic management practices, and the lack of reliable observations and metrics for soil structure recovery rates after compaction motivated the establishment of a long-term Soil Structure Observatory (SSO) at the Agroscope research institute in Zürich, Switzerland. The primary objective of the SSO is to provide long-term observation data on soil structure evolution after disturbance by compaction, enabling quantification of compaction recovery rates and times. The SSO was designed to provide information on recovery of compacted soil under different post-compaction soil management regimes, including natural recovery of bare and vegetated soil as well as recovery with and without soil tillage. This study focused on the design of the SSO and the characterization of the pre- and post-compaction state of the field. We deployed a monitoring network for continuous observation of soil state variables related to hydrologic and biophysical functions (soil water content, matric potential, temperature, soil air O2 and CO2 concentrations, O2 diffusion rates, and redox states) as well as periodic sampling and in situ measurements of infiltration, mechanical impedance, soil porosity, gas and water transport properties, crop yields, earthworm populations, and plot-scale geophysical measurements. Besides enabling quantification of recovery rates of compacted soil, we expect that data provided by the SSO will help improve our general understanding of soil structure dynamics