Using a three-dimensional MHD simulation, we model the quasi-static evolution and the onset of eruption of a coronal flux rope. The simulation begins with a twisted flux rope emerging at the lower ...boundary and pushing into a pre-existing coronal potential arcade field. Then the coronal flux rope settles into a quasi-static rise phase during which an underlying, central sigmoid-shaped current layer forms along the so-called hyperbolic flux tube (HFT), a generalization of the X-line configuration. Our MHD simulation suggests that they are the signatures of the development of the HFT topology and the associated tether-cutting reconnections, and that the central void grows and rises with the reconnections, until the flux rope reaches the critical height for the onset of the torus instability and dynamic eruption ensues.
The kinetics of Li2S electrodeposition onto carbon in lithium–sulfur batteries are characterized. Electrodeposition is found to be dominated by a 2D nucleation and growth process with rate constants ...that depend strongly on the electrolyte solvent. Nucleation is found to require a greater overpotential than growth, which results in a morphology that is dependent on the discharge rate.
We present a set of three-dimensional spherical shell anelastic MHD simulations of the buoyant rise of magnetic flux tubes from the base of the convection zone to a depth of 16 Mm below the ...photosphere. It is found that when a twisted flux tube arches upward due to buoyancy, it rotates out of the plane and thus produces a tilt at the apex. Our simulations show that for tubes with the twist rate that is necessary for a cohesive rise, the twist- induced tilt dominates that caused by the Coriolis force, and furthermore, the twist-induced tilt is of the wrong direction (opposite to the observational Joy's law) if the twist is left-handed (right-handed) in the northern (southern) hemisphere, following the observed hemispheric preference of the sign of the active region twist. It is found that in order for the emerging tube to show the correct tilt direction (consistent with observations), the initial twist rate of the flux tube needs to be less than half of that needed for a cohesive rise. Under such conditions, severe flux loss is found during the rise. We also found that due to the asymmetric stretching of the rising tube by the Coriolis force, a field strength asymmetry develops, with the field in the leading leg (leading in the direction of rotation) of the o7; -shaped emerging tube being stronger than the field in the following leg, which results in a more compact morphology in the leading polarity of the emerging active region.
We perform MHD simulations in a spherical geometry of the evolution of the three-dimensional coronal magnetic field as a twisted magnetic flux tube emerges slowly into the low-b corona previously ...occupied by a potential arcade. We study the evolution of the emerged flux rope in the corona as its twist and magnetic energy increases due to flux emergence. We find two distinct stages of the evolution. The earlier evolution is nearly quasi-static, with the flux rope being able to settle into an neighboring equilibrium when the emergence is stopped. When the twist in the emerged flux rope reaches some critical level, the flux rope is found to undergo kink motion and erupt through the arcade field at a localized region, with most of the arcade field remaining closed. The nonlinear evolution of the kink instability facilitates the loss of confinement of the flux rope by changing its orientation at the apex such that it becomes easier for the flux rope to part and erupt through the arcade. The eruption of the writhing flux rope produces prominence field with -shaped and cross-legged morphologies that have been seen in the cores of some CMEs.
Summary
Background
Hepatitis C virus (HCV) infection has been linked to an increased risk of insulin resistance and carotid atherosclerosis.
Aim
To investigate the association between HCV infection ...and stroke, and the effect of interferon‐based therapy (IBT) on stroke risk in chronic hepatitis C (CHC) patients.
Methods
We conducted a retrospective cohort study that followed up 3113 subjects with a newly detected HCV infection and 12 452 age‐ and gender‐matched subjects without HCV infection selected from a random sample of 106 beneficiaries from the Taiwan National Health Insurance Program up to 5 years. Use of IBT was defined as treatment with interferon alpha, pegylated interferon alpha‐2a or pegylated interferon alpha‐2b for at least 3 months. The hazard ratio (HR) for newly detected stroke was calculated for subjects with HCV compared to those without HCV, and for IBT‐treated HCV patients compared to non‐IBT‐treated HCV patients while adjusting for possible confounding factors.
Results
The overall person‐years of follow‐up were 8624.11 in patients with HCV, 54 533.69 in patients without HCV, 666.65 in IBT‐treated patients, and 7886.49 in nontreated patients. The multivariable‐adjusted hazard ratio (HR) for newly detected stroke was 1.23 for subjects with HCV compared to the age‐ and sex‐matched subjects without HCV (adjusted HR = 1.23, 95% CI = 1.06–1.42, P = 0.008). Moreover, use of IBT significantly reduced the risk of stroke in HCV patients (adjusted HR = 0.39, 95% CI = 0.16–0.95, P = 0.039) after adjusting for known prognostic factors.
Conclusions
Interferon‐based therapy may reduce the long‐term risk of stroke in patients with chronic HCV infection.
Black phosphorous (BP), the most thermodynamically stable allotrope of phosphorus, is a high-mobility layered semiconductor with direct band-gap determined by the number of layers from 0.3 eV (bulk) ...to 2.0 eV (single layer). Therefore, BP is considered as a natural candidate for broadband optical applications, particularly in the infrared (IR) and mid-IR part of the spectrum. The strong light-matter interaction, narrow direct band-gap, and wide range of tunable optical response make BP as a promising nonlinear optical material, particularly with great potentials for infrared and mid-infrared opto-electronics. Herein, we experimentally verified its broadband and enhanced saturable absorption of multi-layer BP (with a thickness of ~10 nm) by wide-band Z-scan measurement technique, and anticipated that multi-layer BPs could be developed as another new type of two-dimensional saturable absorber with operation bandwidth ranging from the visible (400 nm) towards mid-IR (at least 1930 nm). Our results might suggest that ultra-thin multi-layer BP films could be potentially developed as broadband ultra-fast photonics devices, such as passive Q-switcher, mode-locker, optical switcher etc.
Gendered and racial inequalities persist in even the most progressive of workplaces. There is increasing evidence to suggest that all aspects of employment, from hiring to performance evaluation to ...promotion, are affected by gender and cultural background. In higher education, bias in performance evaluation has been posited as one of the reasons why few women make it to the upper echelons of the academic hierarchy. With unprecedented access to institution-wide student survey data from a large public university in Australia, we investigated the role of conscious or unconscious bias in terms of gender and cultural background. We found potential bias against women and teachers with non-English speaking backgrounds. Our findings suggest that bias may decrease with better representation of minority groups in the university workforce. Our findings have implications for society beyond the academy, as over 40% of the Australian population now go to university, and graduates may carry these biases with them into the workforce.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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