We discuss the results of the covariant spectator quark model for the several transitions, where N is the nucleon and a nucleon excitation. More specifically, we present predictions for the form factors and transition amplitudes associated with the resonances , , , and . The estimates based on valence quark degrees of freedom are compared with the available data, particularly with the recent Jefferson Lab data at low and large momentum transfer (). In general the estimates are in good agreement with the empirical data for GeV, with a few exceptions. The results are discussed in terms of the role of the valence quarks and the meson cloud excitations for the different resonances . We also review our results for the resonance and discuss the relevance of the pion cloud component for the magnetic dipole form factor and the electric and Coulomb quadrupole form factors.

A new, simple method for the synthesis of N-(trifluoroacetyl)-protected sulfilimines from sulfides by a transition-metalfree, one-pot protocol is presented. The salient features of this process include the use of low-cost 1,3-dibromo-5,5-dimethylhydantoin, mild reaction conditions, and a broad substrate scope. The safety and robustness of the method has also been demonstrated by operations on a kilogram scale. In addition, a chiral resolution of a corresponding sulfoximine was achieved on a large scale.

N,N-Dimethylformamidines were synthesized from sulfonamides using the Vilsmeier reagent as a cleavage activator. The reactions were performed under mild conditions achieving good to excellent yields. The chemistry presented can also be used as a deprotection strategy when amines or anilines are protected with sulfonyl groups, such as the tosyl group.

Multistep dissociative chemisorption reactions of water with Pd-4 and Pd-7 clusters were studied using density functional theory. The adsorption energies and referred adsorption sites from water molecule (H2O) to partially dissociative (H-2+O and OH+H), then to fully dissociative (O+H+H) configurations are carefully determined. It is found that the adsorption energies of three dissociative reactions are 5-6 times larger than that of water molecule. Atop sites of Pd-4 and Pd-7 clusters are found to be the most stable sites for the adsorbed H2O molecule. For the coadsorption cases of partially and fully dissociated products, H-2 and OH molecules preferably tend to bind at the low coordination (atop or bridge) sites, and O and H atoms prefer to adsorb on the high coordination (hollow) sites. It is also found that the most favorable adsorption sites for the molecular adsorbates (H2O, H-2 and OH) are adjacent to the Pd atoms with the largest site-specific polarizabilities. Therefore, site-specific polarizability is a good predictor of the favorable adsorption sites for the weakly bound molecules. The di r erent directions of charge transfer between the Pd clusters and the adsorbate(s) is observed. Furthermore, the processes of the adsorption, dissociation, and the dissociative products di r usion of H2O are analyzed.

This article is devoted to the study of an M/G/1 queue with a particular vacation discipline. The server is due to take a vacation as soon as it has served exactly N customers since the end of the previous vacation. N may be either a constant or a random variable. If the system becomes empty before the server has served N customers, then it stays idle until the next customer arrival. Such a vacation discipline arises, for example, in production systems and in order picking in warehouses. We determine the joint transform of the length of a visit period and the number of customers in the system at the end of that period. We also derive the generating function of the number of customers at a random instant, and the Laplace-Stieltjes transform of the delay of a customer. (c) 2015 Wiley Periodicals, Inc. Naval Research Logistics 62: 646-658, 2015

Large N matrices underpin the best understood models of emergent spacetime. We suggest that large N matrices can themselves be emergent from simple quantum mechanical spin models with finite dimensional Hilbert spaces. We exhibit the emergence of large N matrices in a nonlocal statistical physics model of order N-2 Ising spins. The spin partition function is shown to admit a large N saddle described by a matrix integral, which we solve. The matrix saddle is dominant at high temperatures, metastable at intermediate temperatures and ceases to exist below a critical order one temperature. The matrix saddle is disordered in a sense we make precise and competes with ordered low energy states. We verify our analytic results by Monte Carlo simulation of the spin system.