1,737 research outputs found
Large scale flow around turbulent spots
Numerical simulations of a model of plane Couette flow focusing on its
in-plane spatio-temporal properties are used to study the dynamics of turbulent
spots.Comment: 16 pages, 6 figure
K-shell photoionization of ground-state Li-like carbon ions [C]: experiment, theory and comparison with time-reversed photorecombination
Absolute cross sections for the K-shell photoionization of ground-state
Li-like carbon [C(1s2s S)] ions were measured by employing the
ion-photon merged-beams technique at the Advanced Light Source. The energy
ranges 299.8--300.15 eV, 303.29--303.58 eV and 335.61--337.57 eV of the
[1s(2s2p)P]P, [1s(2s2p)P]P and [(1s2s)S 3p]P
resonances, respectively, were investigated using resolving powers of up to
6000. The autoionization linewidth of the [1s(2s2p)P]P resonance was
measured to be meV and compares favourably with a theoretical result
of 26 meV obtained from the intermediate coupling R-Matrix method. The present
photoionization cross section results are compared with the outcome from
photorecombination measurements by employing the principle of detailed balance.Comment: 3 figures and 2 table
Power-Based Droop Control in DC Microgrids Enabling Seamless Disconnection From Upstream Grids
This paper proposes a local power-based droop controller for distributed energy resource converters in dc microgrids that are connected to upstream grids by grid-interface converters. During normal operation, the grid-interface converter imposes the microgrid bus voltage, and the proposed controller allows power flow regulation at distributed energy resource converters\u2019 output. On the other hand, during abnormal operation of the grid-interface converter (e.g., due to faults in the upstream grid), the proposed controller allows bus voltage regulation by droop control. Notably, the controller can autonomously convert from power flow control to droop control, without any need of bus voltage variation detection schemes or communication with other microgrid components, which enables seamless transitions between these two modes of operation. Considering distributed energy resource converters employing the power-based droop control, the operation modes of a single converter and of the whole microgrid are defined and investigated herein. The controller design is also introduced. Furthermore, the power sharing performance of this control approach is analyzed and compared with that of classical droop control. The experimental results from a laboratory-scale dc microgrid prototype are reported to show the final performances of the proposed power-based droop control
Products of Nearly Holomorphic Eigenforms
We prove that the product of two nearly holomorphic Hecke eigenforms is again
a Hecke eigenform for only finitely many choices of factors.Comment: 8 page
A systematic review of the relationship between rigidity/flexibility and transdiagnostic cognitive and behavioral processes that maintain psychopathology
An ever-growing number of transdiagnostic processes that maintain psychopathology across disorders
have been identified. However, such processes are not consistently associated with psychological distress
and symptoms. An understanding of what makes such processes pathological is required. One possibility
is that individual differences in rigidity in the implementation of these processes determine the degree of
psychopathology. The aim of this article is to examine the relationship between rigidity/flexibility and
transdiagnostic maintenance processes. Initial searches were made for research examining relationships
between 18 transdiagnostic processes and rigidity/flexibility. Relationships between rumination,
perfectionism, impulsivity and compulsivity, and rigidity/flexibility were systemically reviewed; 50
studies met inclusion criteria. The majority of studies indicated that transdiagnostic cognitive and
behavioral maintenance processes and rigidity were correlated, co-occurring, or predictive of each
other. Findings are consistent with the hypothesis that it is inflexibility in the manner in which
processes are employed that makes them pathologically problematic. However, further research is
required to test and establish this
Photoionization of the fullerene ion C60+
Photoionization cross section of the fullerene ion C60+ has been calculated
within a single-electron approximation and also by using a consistent many-body
theory accounting for many-electron correlations.Comment: 8 pages, 3 figure
The medical student
The Medical Student was published from 1888-1921 by the students of Boston University School of Medicine
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