Soliton self-modulation of the turbulence amplitude and plasma rotation

The space-uniform amplitude envelope of the Ion Temperature Gradient driven turbulence is unstable to small perturbations and evolves to nonuniform, soliton-like modulated profiles. The induced poloidal asymmetry of the transport fluxes can generate spontaneous poloidal spin-up of the tokamak plasma.Comment: Latex file, 66 pages, 24 postscript figures included. New section on rotation five new figures, comparison with magnetic pumping dampin

The role of education in filling the gender gap in financial inclusion in low-income economies

This study aims to investigate whether gender predicts financial inclusion and whether education can fill the gender gap in financial inclusion when controlling for the effects of supply side factors of financial inclusion in low-income economies. This study aims to investigate whether gender predicts financial inclusion and whether education can fill the gender gap in financial inclusion when controlling for the effects of supply side factors of financial inclusion in low-income economies. The findings provided support for the gender gap in financial inclusion using the most basic measure of financial inclusion. However, using formal savings and access to credit, the gender gap hypothesis is not supported. Moreover, the results revealed that education reduces the gender gap in the basic form of financial inclusion. However, this study could not find any significant difference between men and women’s financial inclusion in terms of saving at a bank or borrowing from a bank though men tend to save more than women informally. The current study contributes to the literature by examining the role of education in the relationship between gender gap and financial inclusion when controlling for the effects of heterogeneous infrastructure and the supply side factors of financial inclusion among the selected countries

Transport control by coherent zonal flows in the core/edge transitional regime

3D Braginskii turbulence simulations show that the energy flux in the core/edge transition region of a tokamak is strongly modulated - locally and on average - by radially propagating, nearly coherent sinusoidal or solitary zonal flows. The flows are geodesic acoustic modes (GAM), which are primarily driven by the Stringer-Winsor term. The flow amplitude together with the average anomalous transport sensitively depend on the GAM frequency and on the magnetic curvature acting on the flows, which could be influenced in a real tokamak, e.g., by shaping the plasma cross section. The local modulation of the turbulence by the flows and the excitation of the flows are due to wave-kinetic effects, which have been studied for the first time in a turbulence simulation.Comment: 5 pages, 5 figures, submitted to PR

Experimental observation and characterization of the magnetorotational instability

Differential rotation occurs in conducting flows in accretion disks and planetary cores. In such systems, the magnetorotational instability can arise from coupling Lorentz and centrifugal forces to cause large radial angular momentum fluxes. We present the first experimental observation of the magnetorotational instability. Our system consists of liquid sodium between differentially rotating spheres, with an imposed coaxial magnetic field. We characterize the observed patterns, dynamics and torque increases, and establish that this instability can occur from a hydrodynamic turbulent background.Comment: 4 pages, 5 figures. Final version, accepted for publication in Physical Review Letter

Condensation of microturbulence-generated shear flows into global modes

In full flux-surface computer studies of tokamak edge turbulence, a spectrum of shear flows is found to control the turbulence level and not just the conventional (0,0)-mode flows. Flux tube domains too small for the large poloidal scale lengths of the continuous spectrum tend to overestimate the flows, and thus underestimate the transport. It is shown analytically and numerically that under certain conditions dominant (0,0)-mode flows independent of the domain size develop, essentially through Bose-Einstein condensation of the shear flows.Comment: 5 pages, 4 figure

Diet and mobility in Late Antique Sicily: Isotopic data from the catacombs of Santa Lucia, Siracusa (Italy)

The catacombs of Santa Lucia were built during the 3rd century CE in Siracusa, Sicily, Italy, as a burial site for members of the local Christian community until the early 8th century CE. This site is an important cemeterial context of the Late Roman and Byzantine periods. The tombs and artifacts found suggest that individuals of varying wealth were buried in the catacombs. Historical accounts also confirm the presence of a significant Christian community from Syria and the Levant in Siracusa during this period. The objective of this research is to investigate the life histories of the Late Antique community interred in the catacombs using stable isotope analysis. This technique aimed to clarify the dietary differences between individuals of different social status and geographical origins, in order to re-evaluate the data from historical documents. To achieve this, we conducted stable carbon, nitrogen, and oxygen isotope analyses on skeletal samples from 25 individuals recovered from the catacombs of Santa Lucia, using established methods. The results revealed significant dietary diversity among the individuals buried in the catacombs, with evidence of the consumption of both C3 and C4 plants, as well as fish from both freshwater and sea sources. The oxygen isotopes show a particularly broad range in both the small sample set of bones and the larger set of teeth, suggesting a significant degree of mobility for most of the individuals tested. The high variability found in the diet and the evidence of mobility for most of the individuals tested not only between early age and adulthood, but also throughout their lives. It raises new questions and calls for the consideration of the archaeological and historical implications of these novel discoveries

Understanding the effect of sheared flow on microinstabilities

The competition between the drive and stabilization of plasma microinstabilities by sheared flow is investigated, focusing on the ion temperature gradient mode. Using a twisting mode representation in sheared slab geometry, the characteristic equations have been formulated for a dissipative fluid model, developed rigorously from the gyrokinetic equation. They clearly show that perpendicular flow shear convects perturbations along the field at a speed we denote by $Mc_s$ (where $c_s$ is the sound speed), whilst parallel flow shear enters as an instability driving term analogous to the usual temperature and density gradient effects. For sufficiently strong perpendicular flow shear, $M >1$, the propagation of the system characteristics is unidirectional and no unstable eigenmodes may form. Perturbations are swept along the field, to be ultimately dissipated as they are sheared ever more strongly. Numerical studies of the equations also reveal the existence of stable regions when $M < 1$, where the driving terms conflict. However, in both cases transitory perturbations exist, which could attain substantial amplitudes before decaying. Indeed, for $M \gg 1$, they are shown to exponentiate $\sqrt{M}$ times. This may provide a subcritical route to turbulence in tokamaks.Comment: minor revisions; accepted to PPC

Development and Evaluation of an Expert System for Diagnosing Tinnitus Disease

Tinnitus is a common condition characterized by the perception of sound in the absence of an external source, with potential negative physical and psychological impacts. Accurate and efficient diagnosis of tinnitus is crucial for appropriate treatment and management. Traditional diagnostic methods have limitations in terms of time, cost, and accuracy. To address these challenges, expert systems have emerged as a promising tool for tinnitus diagnosis. This paper explores the application of expert systems in tinnitus diagnosis, highlighting their potential to improve accuracy and efficiency. By incorporating a knowledge base and rule-based decision-making, expert systems can provide valuable insights for accurate diagnosis and appropriate management of tinnitus. Further research and development in this area can enhance the clinical assessment and treatment of tinnitus, ultimately improving the quality of life for affected individuals

Phase Mixing of Alfvén Waves Near a 2D Magnetic Null Point

The propagation of linear Alfvén wave pulses in an inhomogeneous plasma near a 2D coronal null point is investigated. When a uniform plasma density is considered, it is seen that an initially planar Alfvén wavefront remains planar, despite the varying equilibrium Alfvén speed, and that all the wave collects at the separatrices. Thus, in the non-ideal case, these Alfvénic disturbances preferentially dissipate their energy at these locations. For a non-uniform equilibrium density, it is found that the Alfvén wavefront is significantly distorted away from the initially planar geometry, inviting the possibility of dissipation due to phase mixing. Despite this however, we conclude that for the Alfvén wave, current density accumulation and preferential heating still primarily occur at the separatrices, even when an extremely non-uniform density profile is considered