Search results for "QC"
showing 10 items of 3477 documents
Complete 1H and 13C NMR assignments of clerodane diterpenoids of Salvia splendens.
2006
Unambiguous and complete assignments of 1H and 13C NMR chemical shifts for five clerodane diterpenes, four of them isolated from Salvia splendens (salviarin, splendidin and splenolides A and B) and one obtained by acetylation of splenolide A, are presented. The assignments are based on 2D shift-correlated [1H,1H–COSY, 1H,13C-gHSQC–1J(C,H) and 1H,13C-gHMBC-nJ(C,H) (n = 2 and 3)] and nuclear Overhauser effect (NOE) experiments. The conformation of the rings of these compounds is supported by the 3J(H,H) values and NOE results. Copyright © 2006 John Wiley & Sons, Ltd.
The Cauchy problem in hybrid metric-Palatini f(X)-gravity
2013
The well-formulation and the well-posedness of the Cauchy problem is discussed for {\it hybrid metric-Palatini gravity}, a recently proposed modified gravitational theory consisting of adding to the Einstein-Hilbert Lagrangian an $f(R)$ term constructed {\it \`{a} la} Palatini. The theory can be recast as a scalar-tensor one predicting the existence of a light long-range scalar field that evades the local Solar System tests and is able to modify galactic and cosmological dynamics, leading to the late-time cosmic acceleration. In this work, adopting generalized harmonic coordinates, we show that the initial value problem can always be {\it well-formulated} and, furthermore, can be {\it well-…
Effect of blastfurnace slag addition to Portland cement for cationic exchange resins encapsulation
2013
In the nuclear industry, cement-based materials are extensively used to encapsulate spent ion exchange resins (IERs) before their final disposal in a repository. It is well known that the cement has to be carefully selected to prevent any deleterious expansion of the solidified waste form, but the reasons for this possible expansion are not clearly established. This work aims at filling the gap. The swelling pressure of IERs is first investigated as a function of ions exchange and ionic strength. It is shown that pressures of a few tenths of MPa can be produced by decreases in the ionic strength of the bulk solution, or by ion exchanges (2Na + instead of Ca 2+ , Na + instead of K + ). Then,…
Comprehensive analysis of expression, subcellular localization, and cognate pairing of SNARE proteins in oligodendrocytes
2009
Oligodendrocytes form the central nervous system myelin sheath by spiral wrapping of their plasma membrane around axons, necessitating a high rate of exocytic membrane addition to the growing myelin membrane. Membrane fusion is mediated by soluble N-ethylmaleimide-sensitive factor attachment protein receptor proteins (SNAREs), which act by specific pairing of vesicle (R)- and target (Q)-SNAREs. To characterize oligodendroglial SNAREs and their trafficking pathways, we performed a detailed expression analysis of SNAREs in differentiating cultured oligodendrocytes and myelin and determined their subcellular localization. Expression of the plasma membrane Q-SNAREs syntaxin 3, syntaxin 4, SNAP2…
The Effect of Taper and Apical Diameter on the Cyclic Fatigue Resistance of Rotary Endodontic Files Using an Experimental Electronic Device
2021
The aim of this study was to analyze the effect of the taper and apical diameter of nickel&ndash
Adversarial reverse mapping of condensed-phase molecular structures: Chemical transferability
2021
Switching between different levels of resolution is essential for multiscale modeling, but restoring details at higher resolution remains challenging. In our previous study we have introduced deepBackmap: a deep neural-network-based approach to reverse-map equilibrated molecular structures for condensed-phase systems. Our method combines data-driven and physics-based aspects, leading to high-quality reconstructed structures. In this work, we expand the scope of our model and examine its chemical transferability. To this end, we train deepBackmap solely on homogeneous molecular liquids of small molecules, and apply it to a more challenging polymer melt. We augment the generator's objective w…
Overview of the JET results
2015
Since the installation of an ITER-like wall, the JET programme has focused on the consolidation of ITER design choices and the preparation for ITER operation, with a specific emphasis given to the bulk tungsten melt experiment, which has been crucial for the final decision on the material choice for the day-one tungsten divertor in ITER. Integrated scenarios have been progressed with the re-establishment of long-pulse, high-confinement H-modes by optimizing the magnetic configuration and the use of ICRH to avoid tungsten impurity accumulation. Stationary discharges with detached divertor conditions and small edge localized modes have been demonstrated by nitrogen seeding. The differences in…
Ion motion in salt water flowing under a transverse magnetic field
2012
The problem of ion motion in an electrolyte solution flowing in a thin rectangular duct with velocity VE in the presence of a transverse magnetic field B0 is studied by means of classical mechanics and electrodynamics. Because of Lorentz force on the ions in the electrolyte solution, a so called Faraday voltage appears at the electrodes orthogonal to both the field B0 and the velocity VE. The dynamics of positive and negative ions (cations and anions, respectively) in this classical system is studied by taking into account the viscosity of the fluid and the process of charge accumulation on the opposite walls of the duct. Hydrogen production is seen to take place at one of the electrodes wh…
In situ observations of CH2Cl2 and CHCl3 show efficient transport pathways for very short-lived species into the lower stratosphere via the Asian and…
2022
Efficient transport pathways for ozone-depleting very short-lived substances (VSLSs) from their source regions into the stratosphere are a matter of current scientific debate; however they have yet to be fully identified on an observational basis. Understanding the increasing impact of chlorine-containing VSLSs (Cl-VSLSs) on stratospheric ozone depletion is important in order to validate and improve model simulations and future predictions. We report on a transport study using airborne in situ measurements of the Cl-VSLSs dichloromethane (CH2Cl2) and trichloromethane (chloroform, CHCl3) to derive a detailed description of two transport pathways from (sub)tropical source regions into the ext…
Lightning-ignited wildfires and long continuing current lightning in the Mediterranean Basin: preferential meteorological conditions
2021
Lightning is the major cause of the natural ignition of wildfires worldwide and produces the largest wildfires in some regions. Lightning strokes produce about 5 % of forest fires in the Mediterranean Basin and are one of the most important precursors of the largest forest fires during the summer. Lightning-ignited wildfires produce significant emissions of aerosols, black carbon, and trace gases, such as CO, SO2, CH4, and O3, affecting air quality. Characterization of the meteorological and cloud conditions of lightning-ignited wildfires in the Mediterranean Basin can serve to improve fire forecasting models and to upgrade the implementation of fire emissions in atmospheric models. This st…