6,654 research outputs found
NMR Line Shape Analysis of a Multi-state Ligand Binding Mechanism in Chitosanase
Chitosan interaction with chitosanase was examined through analysis of spectral line shapes in the NMR HSQC titration experiments. We established that the substrate, chitosan hexamer, binds to the enzyme through the three-state induced-fit mechanism with fast formation of the encounter complex followed by slow isomerization of the bound-state into the final conformation. Mapping of the chemical shift perturbations in two sequential steps of the mechanism highlighted involvement of the substrate-binding subsites and the hinge region in the binding reaction. Equilibrium parameters of the three-state model agreed with the overall thermodynamic dissociation constant determined by ITC. This study presented the first kinetic evidence of the induced-fit mechanism in the glycoside hydrolases
Final report of grit blasting and metal spraying trials carried out at H. M. Dockyard, Devonport
Mild steel surfaces that are to be protected by aluminium or
zinc spray coatings are generally prepared by blasting with chilled
iron angular grit. Previous work1had shown that a relationship
exists between the grit blasting conditions (at least in terms of
blasting angle and grit condition), the reflectivity of the blasted
surface and the bond strength of a spray coating of aluminium on the
blasted surface. An instrument has been developed that assesses the
suitability of a blasted surface for subsequent spraying by measuring
the reflectivity and has proved reasonably successful under laboratory
conditions. The present need is to ascertain the performance of this
reflectivity meter under shop and site conditions. The opportunity
to carry out such tests at H.M. Dockyard, Devonport, was offered by the
Ministry of Defence and a series of tests was made on 16th June, 1965
Extended Partial-Wave Analysis of piN Scattering Data
We present results from a comprehensive partial-wave analysis of pi+-p
elastic scattering and charge-exchange data, covering the region from threshold
to 2.6 GeV in the lab pion kinetic energy, employing a coupled-channel
formalism to simultaneously fit pi-p-->eta n data to 0.8 GeV. Our main result,
solution SP06, utilizes a complete set of forward and fixed-t dispersion
relation constraints applied to the piN elastic amplitude. The results of these
analyses are compared with previous solutions in terms of their resonance
spectra and preferred values for couplings and low-energy parameters.Comment: 21 pages, 11 figure
Indo-Uralic and Altaic
Elsewhere I have argued that the Indo-European verbal system can be understood in terms of its Indo-Uralic origins because the reconstructed Indo-European endings can be derived from combinations of Indo-Uralic morphemes by a series of well-motivated phonetic and analogic developments (2002). Moreover, I have claimed (2004b) that the Proto-Uralic consonant gradation accounts for the peculiar correlations between Indo-European root structure and accentuation discovered by Lubotsky (1988)
Distributed Optimal Frequency Control Considering a Nonlinear Network-Preserving Model
This paper addresses the distributed optimal frequency control of power
systems considering a network-preserving model with nonlinear power flows and
excitation voltage dynamics. Salient features of the proposed distributed
control strategy are fourfold: i) nonlinearity is considered to cope with large
disturbances; ii) only a part of generators are controllable; iii) no load
measurement is required; iv) communication connectivity is required only for
the controllable generators. To this end, benefiting from the concept of
'virtual load demand', we first design the distributed controller for the
controllable generators by leveraging the primal-dual decomposition technique.
We then propose a method to estimate the virtual load demand of each
controllable generator based on local frequencies. We derive incremental
passivity conditions for the uncontrollable generators. Finally, we prove that
the closed-loop system is asymptotically stable and its equilibrium attains the
optimal solution to the associated economic dispatch problem. Simulations,
including small and large-disturbance scenarios, are carried on the New England
system, demonstrating the effectiveness of our design
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