4,405 research outputs found
Target-mass corrections and the Bloom-Gilman duality of the nucleon structure function
The occurrence of the Bloom-Gilman local duality in the low-order moments of
the nucleon structure function is investigated for values of the squared
four-momentum transfer Q**2 between ~ 0.5 and 10 (GeV/c)**2. At variance with
previous analyses truncated Cornwall-Norton moments, limited to the
nucleon-resonance production regions, are considered. The role played by
target-mass corrections is illustrated, showing that target-mass effects are
necessary (but not sufficient) for producing the observed Bloom-Gilman duality
of the nucleon structure function. The possibility of a local duality between
the unphysical region at large values of the Nachtmann variable and the nucleon
elastic peak contribution is analyzed. It is found that the proton magnetic
form factor extracted assuming local duality is significantly below the
experimental data at low and intermediate values of Q**2.Comment: final version with minor modifications, to appear in Phys. Lett.
PENGARUH TOTAL QUALITY MANAGEMENT DAN GREEN SUPPLY CHAIN MANAGEMENT TERHADAP CORPORATE SUSTAINABILITY PERFORMANCE DIMEDIASI COMPETITIVE ADVANTAGE
The aim of this research is to analyze the influence of total quality management and green supply chain management on corporate sustainability performance, mediated by competitive advantage directly or indirectly. This type of research is explanatory with sampling using a purposive sampling method. The number of samples that met the criteria was 102 respondents who were owners of Sanan tempeh chips SMEs in Malang city. This data was obtained through distributing questionnaires directly. The data analysis technique used in this research is Structural Equation Modeling (SEM) with the SmartPLS analysis tool. The research results show that total quality management has no significant effect on corporate sustainability performance, green supply chain management and competitive advantage have a significant effect on corporate sustainability performance, total quality management and green supply chain management have a significant effect on competitive advantage, Competitive advantage fully mediates the effect of green supply chain management on corporate sustainability performance, Competitive advantage partially mediates the influence of green supply chain management on corporate sustainability performance
Soft gluon effects in the extraction of higher twists at large Bjorken x
Existing data on the (unpolarised) transverse structure function of the
proton are analyzed for large values of the Bjorken variable x. The
leading-twist and a phenomenological higher-twist contributions are
simultaneously determined from a power correction analysis of the Nachtmann
moments for values of the squared four-momentum transfer between ~ 1 and 20
(GeV/c)**2. The results obtained adopting the next-to-leading order
approximation and those including the effects of soft gluon resummation are
compared. The sensitivity of the extraction of large-x higher twists to
high-order radiative corrections as well as to the value of alphas(MZ) is
illustrated.Comment: revised version to appear in Phys. Lett. B: discussion of
higher-twist models included; misprints in Eq. (1) and (10) correcte
Brane superpotential and local Calabi-Yau manifolds
We briefly report on some recent progress in the computation of B-brane
superpotentials for Type II strings compactified on Calabi-Yau manifolds,
obtained by using a parametrization of tubular neighborhoods of complex
submanifolds, also known as local spaces. In particular, we propose a closed
expression for the superpotential of a brane on a genus-g curve in a Calabi-Yau
threefold in the case in which there exists a holomorphic projection from the
local space around the curve to the curve itself.Comment: 3 pages, contribution to the proceedings of the workshop "Progress of
String Theory and Quantum Field Theory", Osaka City University, December 200
Normal bundles to Laufer rational curves in local Calabi-Yau threefolds
We prove a conjecture by F. Ferrari. Let X be the total space of a nonlinear
deformation of a rank 2 holomorphic vector bundle on a smooth rational curve,
such that X has trivial canonical bundle and has sections. Then the normal
bundle to such sections is computed in terms of the rank of the Hessian of a
suitably defined superpotential at its critical points
Laminar Streaks in Oscillating Boundary Layers
Acknowledgements This research was partially supported by EPSRC First Grant EP/I033173/1 and made use of computing resources at the University of Aberdeen and the University of Sheffield.Non peer reviewedPublisher PD
The transmission of monetary policy shocks
Commonly used instruments for the identification of monetary policy disturbances are likely to combine the true policy shock with information about the state of the economy due to the information disclosed through the policy action. We show that this signalling effect of monetary policy can give rise to the empirical puzzles reported in the literature, and propose a new high-frequency instrument for monetary policy shocks that accounts for informational rigidities. We find that a monetary tightening is unequivocally contractionary, with deterioration of domestic demand, labor and credit market conditions, as well as of asset prices and agents' expectations
Streamwise-traveling waves of spanwise wall velocity for turbulent drag reduction
Waves of spanwise velocity imposed at the walls of a plane turbulent channel
flow are studied by Direct Numerical Simulations. We consider sinusoidal waves
of spanwise velocity which vary in time and are modulated in space along the
streamwise direction. The phase speed may be null, positive or negative, so
that the waves may be either stationary or traveling forward or backward in the
direction of the mean flow. Such a forcing includes as particular cases two
known techniques for reducing friction drag: the oscillating wall technique (a
traveling wave with infinite phase speed) and the recently proposed steady
distribution of spanwise velocity (a wave with zero phase speed).
The traveling waves alter the friction drag significantly. Waves which slowly
travel forward produce a large reduction of drag, that can relaminarize the
flow at low values of the Reynolds number. Faster waves yield a totally
different outcome, i.e. drag increase. Even faster waves produce a drag
reduction effect again. Backward-traveling waves instead lead to drag reduction
at any speed.
The traveling waves, when they reduce drag, operate in similar fashion to the
oscillating wall, with an improved energetic efficiency. Drag increase is
observed when the waves travel at a speed comparable with that of the
convecting near-wall turbulence structures. A diagram illustrating the
different flow behaviors is presented
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