196 research outputs found
Status of the RFX experiment
The first results obtained in the RFX reversed field pinch experiment after the 1995 machine modifications are reported. The confinement, for fully stationary discharges at 0.6 MA, has now reached the expected values, even in the presence of MHD wall locked modes. Studies on locked mode effects have evidenced currents flowing from the plasma into the vessel in the region of locking. Measurements on plasma rotation and radial electric field have shown a perpendicular velocity shear at the edge similar to what is found in tokamaks and stellarators. New measurements on edge superthermal electrons and some evidence of their correlation with plasma core characteristics are included
Investigation of Impurity Tracer Transport in High Density Plasmas at the Stellarator Wendelstein 7-AS
Follow-Up Assessment of Intracranial Aneurysms Treated with Endovascular Coiling: Comparison of Compressed Sensing and Parallel Imaging Time-of-Flight Magnetic Resonance Angiography
The aim of our study was to compare compressed sensing (CS) time-of-flight (TOF) magnetic resonance angiography (MRA) with parallel imaging (PI) TOF MRA in the evaluation of patients with intracranial aneurysms treated with coil embolization or stent-assisted coiling. We enrolled 22 patients who underwent follow-up imaging after intracranial aneurysm coil embolization. All patients underwent both PI TOF and CS TOF MRA during the same examination. Image evaluation aimed to compare the performance of CS to PI TOF MRA in determining the degree of aneurysm occlusion, as well as the depiction of parent vessel and vessels adjacent to the aneurysm dome. The reference standard for the evaluation of aneurysm occlusion was PI TOF MRA. The inter-modality agreement between CS and PI TOF MRA in the evaluation of aneurysm occlusion was almost perfect (κ = 0.98, p < 0.001) and the overall inter-rater agreement was substantial (κ = 0.70, p < 0.001). The visualization of aneurysm parent vessel in CS TOF images compared with PI TOF images was evaluated to be better in 11.4%, equal in 86.4%, and worse in 2.3%. CS TOF MRA, with almost 70% scan time reduction with respect to PI TOF MRA, yields comparable results for assessing the occlusion status of coiled intracranial aneurysms. Short scan times increase patient comfort, reduce the risk of motion artifacts, and increase patient throughput, with a resulting reduction in costs. CS TOF MRA may therefore be a potential replacement for PI TOF MRA as a first-line follow-up examination in patients with intracranial aneurysms treated with coil embolization
Side-chain Poly[2]pseudorotaxanes containing β-cyclodextrin for more sustainable tanning process
Sustainability of leather lies in how the hide, a sustainable, naturally renewable, raw material, is processed. Tanning chemistry has been a limiting factor for leather sustainability. In this study, a host-guest synthesis strategy was selected to modify one of the most widely used tanning polymer, MIDA DD, and obtain a new hybrid tanning system containing fl-cyclodextrin, and leather drastically less impactful on the earth and people. Poly[2] pseudorotaxane Side-Chain Complexes (PSCCs) have been obtained by threading fl-cyclodextrin units onto the side-chains of the commercial MIDA DD. The formation of PSCCs in aqueous solution was investigated by using 1D NMR, ATR-FTIR and TGA experiments. The ability of PSCCs to stabilize the collagen matrix was tested at laboratory and industrial pilot scale by micro-DSC, ATR-FTIR and solid-state NMR techniques. The physical and mechanical performance of the obtained crust leather was determined by standard tests used in tanning industry. Side-chain poly[2]pseudorotaxanes showed better tanning performances than the fossil-based MIDA DD, the most effective supramolecular tannins being obtained by mixing fl-CD and MIDA DD in ratios close to 1/1 (w/w). The new tanning mixtures allow for significantly reducing both the amount of fossil-based MIDA-DD polymer in the current tanning processes (by 45%) and the free bisphenol content in leather crust (by more than 80%) due to the presence of bio-based fl-CD in the composition of the new supramolecular tanning agents. The findings disclosed here pave the way for the CDs' employment in improving the sustainability of tanning processes
Confinement Studies on ASDEX in the Intermediate Region from Ohmic to Neutral Injection Scaling
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