Understanding the core density profile in TCV H-mode plasmas

Results from a database analysis of H-mode electron density profiles on the Tokamak \`a Configuration Variable (TCV) in stationary conditions show that the logarithmic electron density gradient increases with collisionality. By contrast, usual observations of H-modes showed that the electron density profiles tend to flatten with increasing collisionality. In this work it is reinforced that the role of collisionality alone, depending on the parameter regime, can be rather weak and in these, dominantly electron heated TCV cases, the electron density gradient is tailored by the underlying turbulence regime, which is mostly determined by the ratio of the electron to ion temperature and that of their gradients. Additionally, mostly in ohmic plasmas, the Ware-pinch can significantly contribute to the density peaking. Qualitative agreement between the predicted density peaking by quasi-linear gyrokinetic simulations and the experimental results is found. Quantitative comparison would necessitate ion temperature measurements, which are lacking in the considered experimental dataset. However, the simulation results show that it is the combination of several effects that influences the density peaking in TCV H-mode plasmas.Comment: 23 pages, 12 figure

Rozlišení lokálního uspořádání Ga a Ge v amorfním (Ga2Se3) 0,25 (GeSe2) 0,75 metodou anomální ho rentgenového rozptylu

The amorphous structure of (Ga2Se3)0.25(GeSe2)0.75 is investigated using a combination of anomalous X-ray scattering (AXS) and Reverse-Monte-Carlo (RMC) modeling. It was confirmed that the Ga and Ge atoms can be found exclusively in the tetrahedral configuration. The average coordination number of the Se atoms is found to be 2.34(3) due to the presence of dative bonds. The formation of Ga/Ge-Ga/Ge so-called “wrong bonds” is discussed based on a set of RMC simulations. A strong Ga-Ga second neighbor correlations indicates the formation of Ga-Se clusters within the Ga-Ge-Se glass.Amorfní struktura (Ga2Se3)0.25(GeSe2)0.75 je zkoumána kombinací anomalního rentgenového rozptylu (AXS) a modelováním pomocí reverzního Monte-Carla (RMC). Bylo potvrzeno, že Ga a Ge atomy existují exkluzivně v tetraedrické konfiguraci. Průměrné koordinační číslo atomů Se je 2.34(3) kvůli přítomnosti dativních vazeb. Tvorba Ga/Ge-Ga/Ge takzvaných „homopolárních vazeb“ je diskutována pomocí RMC simulací. Silná korelace Ga-Ga v druhé koordinační sféře naznačuje tvorbu Ga-Se klastrů uvnitř Ga-Ge-Se skla

Examination of carbohydrate metabolism parameters after simultaneous pancreas-kidney transplantation.

End-stage renal failure, a frequent complication of type 1 diabetes mellitus, requires renal replacement therapy. Our team examined the laboratory parameters of carbohydrate metabolism in 18 patients with type 1 diabetes at 10 to 89 months after simultaneous pancreas-kidney transplantation. We compared these results with those of 17 patients with type 1 diabetes who had formerly received kidney-alone transplantations, and were undergoing insulin treatment, as well as with those of 16 metabolically healthy controls. The hemoglobin A1c (HbA1c) and blood glucose levels of the pancreas-kidney transplant recipients were within the normal ranges, not differing significantly from those of the healthy controls. In contrast, the HbA1c and glucose levels were significantly elevated among kidney transplanted diabetic subjects. However, fasting and 2-hour insulin levels of pancreas-kidney transplant patients were significantly higher than those of the controls, indicating insulin resistance. According to these results, the insulin secretion by the pancreas graft sufficiently compensated for insulin resistance. Thus 10 to 89 months after successful pancreas-kidney transplantation, carbohydrate metabolism by type 1 diabetic patients was well controlled without antidiabetic therapy

Microalgae and cyanobacteria modeling in water resource recovery facilities: A critical review

Microalgal and cyanobacterial resource recovery systems could significantly advance nutrient recovery from wastewater by achieving effluent nitrogen (N) and phosphorus (P) levels below the current limit of technology. The successful implementation of phytoplankton, however, requires the formulation of process models that balance fidelity and simplicity to accurately simulate dynamic performance in response to environmental conditions. This work synthesizes the range of model structures that have been leveraged for algae and cyanobacteria modeling and core model features that are required to enable reliable process modeling in the context of water resource recovery facilities. Results from an extensive literature review of over 300 published phytoplankton models are presented, with particular attention to similarities with and differences from existing strategies to model chemotrophic wastewater treatment processes (e.g., via the Activated Sludge Models, ASMs). Building on published process models, the core requirements of a model structure for algal and cyanobacterial processes are presented, including detailed recommendations for the prediction of growth (under phototrophic, heterotrophic, and mixotrophic conditions), nutrient uptake, carbon uptake and storage, and respiration. Keywords: Growth, Nutrient uptake, Lipid storage, Starch storage, Wastewater treatment plant (WWTP

Analysis of lithium driven electron density peaking in FTU liquid lithium limiter experiments

The impact of lithium impurities on the microstability and turbulent transport characteristics in the core of a typical FTU liquid lithium limiter (LLL) (Mazzitelli et al 2011 Nucl. Fusion 51 073006) discharge during the density ramp-up phase is studied. A non-linear gyrokinetic analysis performed with GKW (Peeters et al 2009 Comput. Phys. Commun. 180 2650) accompanied by a quasi-linear fluid analysis is presented. We show that a centrally peaked, high concentration lithium profile contributes to the electron peaking by reducing the outward electron flux, and that it leads to inward turbulent deuterium transport through ion flux separation