1,101 research outputs found
Real-time control of divertor detachment in H-mode with impurity seeding using Langmuir probe feedback in JET-ITER-like wall
Burning plasmas with 500 MW of fusion power on ITER will rely on partially detached divertor
operation to keep target heat loads at manageable levels. Such divertor regimes will be
maintained by a real-time control system using the seeding of radiative impurities like nitrogen
(N), neon or argon as actuator and one or more diagnostic signals as sensors. Recently, real-time
control of divertor detachment has been successfully achieved in Type I ELMy H-mode JETITER-like wall discharges by using saturation current (Isat) measurements from divertor
Langmuir probes as feedback signals to control the level of N seeding. The degree of divertor
detachment is calculated in real-time by comparing the outer target peak Isat measurements to the
peak Isat value at the roll-over in order to control the opening of the N injection valve. Real-time
control of detachment has been achieved in both fixed and swept strike point experiments. The
system has been progressively improved and can now automatically drive the divertor conditions
from attached through high recycling and roll-over down to a user-defined level of detachment.
Such a demonstration is a successful proof of principle in the context of future operation on
ITER which will be extensively equipped with divertor target probes
Phase IV open-label study of the efficacy and safety of deferasirox after allogeneic stem cell transplantation
This is the first prospective study of deferasirox in adult allogeneic hematopoietic stem cell transplant recipients with transfusional iron overload in hematologic malignancies. Patients at least six months post transplant were treated with deferasirox at a starting dose of 10 mg/kg/day for 52 weeks or until serum ferritin was less than 400 ng/mL on two consecutive occasions. Thirty patients were enrolled and 22 completed the study. A significant reduction from baseline in median serum ferritin and in liver iron concentration at 52 weeks was observed in the overall population: from 1440 to 755.5 ng/mL (P=0.002) and from 14.5 to 4.6 mg Fe/g dw (P=0.0007), respectively. Reduction in serum ferritin in patients who did not discontinue deferasirox therapy was significantly greater than that found in those who prematurely discontinued the treatment (from 1541 to 581 ng/mL vs. from 1416 to 1486 ng/mL; P=0.008). Drug-related adverse events, reported in 17 patients (56.7%), were mostly mild to moderate in severity. There were no drug-related serious adverse events. Twelve patients (40.0%) showed an increase of over 33% in serum creatinine compared to baseline and greater than the upper limit of normal on two consecutive visits. Two patients (6.7%) with active graft-versus-host disease showed an increase in alanine aminotransferase exceeding 10 times upper limit of normal; both resolved. In this prospective study, deferasirox provided a significant reduction in serum ferritin and liver iron concentration over one year of treatment in allogeneic hematopoietic stem cell transplant recipients with iron overload. In addition, the majority of adverse events related to deferasirox were mild or moderate in severity. (clinicaltrials.gov identifier:01335035)
The number of transmission channels through a single-molecule junction
We calculate transmission eigenvalue distributions for Pt-benzene-Pt and
Pt-butadiene-Pt junctions using realistic state-of-the-art many-body
techniques. An effective field theory of interacting -electrons is used to
include screening and van der Waals interactions with the metal electrodes. We
find that the number of dominant transmission channels in a molecular junction
is equal to the degeneracy of the molecular orbital closest to the metal Fermi
level.Comment: 9 pages, 8 figure
Obesity and Cardiometabolic Risk Factors: From Childhood to Adulthood
Obesity has become a major epidemic in the 21st century. It increases the risk of dyslipidemia, hypertension, and type 2 diabetes, which are known cardiometabolic risk factors and components of the metabolic syndrome. Although overt cardiovascular (CV) diseases such as stroke or myocardial infarction are the domain of adulthood, it is evident that the CV continuum begins very early in life. Recognition of risk factors and early stages of CV damage, at a time when these processes are still reversible, and the development of prevention strategies are major pillars in reducing CV morbidity and mortality in the general population. In this review, we will discuss the role of well-known but also novel risk factors linking obesity and increased CV risk from prenatal age to adulthood, including the role of perinatal factors, diet, nutrigenomics, and nutri-epigenetics, hyperuricemia, dyslipidemia, hypertension, and cardiorespiratory fitness. The importance of 'tracking' of these risk factors on adult CV health is highlighted and the economic impact of childhood obesity as well as preventive strategies are discussed
Interaction of two modulational instabilities in a semiconductor resonator
The interaction of two neighboring modulational instabilities in a coherently driven semiconductor cavity is investigated. First, an asymptotic reduction of the general equations is performed in the limit of a nearly vertical input-output characteristic. Next, a normal form is derived in the limit where the two instabilities are close to one other. An infinity of branches of periodic solutions are found to emerge from the unstable portion of the homogeneous branch. These branches have a nontrivial envelope in the bifurcation diagram that can either smoothly join the two instability points or form an isolated branch of solutions
Phase-Locked Spatial Domains and Bloch Domain Walls in Type-II Optical Parametric Oscillators
We study the role of transverse spatial degrees of freedom in the dynamics of
signal-idler phase locked states in type-II Optical Parametric Oscillators.
Phase locking stems from signal-idler polarization coupling which arises if the
cavity birefringence and/or dichroism is not matched to the nonlinear crystal
birefringence. Spontaneous Bloch domain wall formation is theoretically
predicted and numerically studied. Bloch walls connect, by means of a
polarization transformation, homogeneous regions of self-phase locked
solutions. The parameter range for their existence is analytically found. The
polarization properties and the dynamics of walls in one- and two transverse
spatial dimensions is explained. Transition from Bloch to Ising walls is
characterized, the control parameter being the linear coupling strength. Wall
dynamics governs spatiotemporal dynamical states of the system, which include
transient curvature driven domain growth, persistent dynamics dominated by
spiraling defects for Bloch walls, and labyrinthine pattern formation for Ising
walls.Comment: 27 pages, 16 figure
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