4,185 research outputs found
Nonperturbative resonant strong field ionization of atomic hydrogen
We investigate resonant strong field ionization of atomic hydrogen with
respect to the 1s-2p-transition. By "strong" we understand that Rabi-periods
are executed on a femtosecond time scale. Ionization and AC Stark shifts modify
the bound state dynamics severely, leading to nonperturbative signatures in the
photoelectron spectra. We introduce an analytical model, capable of predicting
qualitative features in the photoelectron spectra such as the positions of the
Autler-Townes peaks for modest field strengths. Ab initio solutions of the
time-dependent Schroedinger equation show a pronounced shift and broadening of
the left Autler-Townes peak as the field strength is increased. The right peak
remains rather narrow and shifts less. This result is analyzed and explained
with the help of exact AC Stark shifts and ionization rates obtained from
Floquet theory. Finally, it is demonstrated that in the case of finite pulses
as short as 20fs the Autler-Townes duplet can still be resolved. The fourth
generation light sources under construction worldwide will provide bright,
coherent radiation with photon energies ranging from a tenth of a meV up to
tens of keV, hence covering the regime studied in the paper so that
measurements of nonperturbative, relative AC Stark shifts should become
feasible with these new light sources.Comment: 16 pages, 11 figures, IOP styl
Quality assurance for the ALICE Monte Carlo procedure
We implement the already existing macro,$ALICE_ROOT/STEER /CheckESD.C that is
ran after reconstruction to compute the physics efficiency, as a task that will
run on proof framework like CAF. The task was implemented in a C++ class called
AliAnalysisTaskCheckESD and it inherits from AliAnalysisTaskSE base class. The
function of AliAnalysisTaskCheckESD is to compute the ratio of the number of
reconstructed particles to the number of particle generated by the Monte Carlo
generator.The class AliAnalysisTaskCheckESD was successfully implemented. It
was used during the production for first physics and permitted to discover
several problems (missing track in the MUON arm reconstruction, low efficiency
in the PHOS detector etc.). The code is committed to the SVN repository and
will become standard tool for quality assurance.Comment: 7 pages, 7 figure
On BPS bounds in D=4 N=2 gauged supergravity II: general matter couplings and black hole masses
We continue the analysis of BPS bounds started in arXiv:1110.2688, extending
it to the full class of N=2 gauged supergravity theories with arbitrary vector
and hypermultiplets. We derive the general form of the asymptotic charges for
asymptotically flat (M_4), anti-de Sitter (AdS_4), and magnetic anti-de Sitter
(mAdS_4) spacetimes. Some particular examples from black hole physics are given
to explicitly demonstrate how AdS and mAdS masses differ when solutions with
non-trivial scalar profiles are considered.Comment: 21 pages; v2 added reference, published version; v3 minor correction
Nonlinear Terms of MHD Equations for Homogeneous Magnetized Shear Flow
We have derived the full set of MHD equations for incompressible shear flow
of a magnetized fluid and considered their solution in the wave-vector space.
The linearized equations give the famous amplification of slow magnetosonic
waves and describe the magnetorotational instability. The nonlinear terms in
our analysis are responsible for the creation of turbulence and self-sustained
spectral density of the MHD (Alfven and pseudo-Alfven) waves. Perspectives for
numerical simulations of weak turbulence and calculation of the effective
viscosity of accretion disks are shortly discussed in k-space.Comment: 13 pages, no figures; AIP Conference Proceedings 1356, Proceedings of
the School and Workshop on Space Plasma Physics (1--12 September 2010, Kiten,
Bulgaria), American Institute of Physics, Melville, NY, 201
Thermal impedance estimations by semi-derivatives and semi-integrals: 1-D semi-infinite cases
Simple 1-D semi-infinite heat conduction problems enable to demonstrate the potential of the fractional calculus in determination of transient thermal impedances under various boundary conditions imposed at the interface (x=0). The approach is purely analytic and very effective because it uses only simple semi-derivatives (half-time) and semi-integrals and avoids development of entire domain solutions. 0x
Does distributed leadership have a place in destination management organisations? A policy-makers perspective
Within an increasingly networked environment and recent transitions in the landscape of funding for destination management organisations (DMOs) and destinations, pooling knowledge and resources may well be seen as a prerequisite to ensuring the long-term sustainability of reshaped, yet financially constrained DMOs facing severe challenges to deliver value to destinations, visitors and member organisations. Distributed Leadership (DL) is a recent paradigm gaining momentum in destination research as a promising response to these challenges. Building on the scarce literature on DL in a DMO context, this paper provides a policy-makers’ perspective into the place of DL in reshaped DMOs and DMOs undergoing transformation and explores current challenges and opportunities to the enactment and practice of DL. The underpinned investigation used in-depth, semi-structured interviews with policy-makers from VisitEngland following an interview agenda based on the DMO Leadership Cycle. Policy-makers within VisitEngland saw a multitude of opportunities for DMOs with regards to DL, but equally, they emphasised challenges acting as barriers to realising the potential benefits of introducing a DL model to DMOs as a response to uncertainty in the funding landscape
Non-Financial Resources to Enhance Companies’ Profitability: A Stakeholder Perspective
Purpose
This study aims to investigate the impact of stakeholders’ nonfinancial resources (NFRs) on companies’ profitability, filling a significant gap in the literature regarding the role of NFRs in value creation.
Design/methodology/approach
Data from 76 organizations from 2017 to 2019 were collected and analyzed. Four primary NFRs and their key value drivers were identified, representing core elements that support different dimensions of a company’s performance. Statistical tests examined the relationship between stakeholders’ NFRs and financial performance measures.
Findings
When analyzed collectively and individually, the results reveal a significant positive influence of stakeholders’ NFRs on a firm’s profitability. Higher importance assigned to NFRs correlates with a higher return on sales.
Originality/value
This study contributes to the literature by empirically bridging the gap between stakeholder theory and the resource-based view, addressing the intersection of these perspectives. It also provides novel insights into how stakeholders’ NFRs impact profitability, offering valuable implications for research and managerial practice. It suggests that managers should integrate nonfinancial measures of NFRs within their performance measurement system to manage better and sustain companies’ value-creation process
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