Gluon sivers and experimental considerations for TMDs

The study and characterisation of transverse-momentum-dependent distribution functions (TMDs) is a major goal of the Electron-Ion Collider (EIC) physics programme. The study of gluon TMDs poses a greater challenge than for quark TMDs in DIS measurements, as gluons do not directly couple to photons. The study of D meson pairs has been proposed to provide access to gluon TMDs, but is demanding due to the rarity of D production. Here, we discuss the feasibility of such a measurement, and touch upon wider issues to be considered when measuring TMDs at the EIC.Comment: 4 pages, 2 figures, DIS 2012 conferenc

A Single-armed Manta-board as a New Diver-controlled Planing Board and Its Use for Underwater Surveys

Due to inadequacies of previous underwater towing techniques and the special needs of a recent underwater survey, a modified mania-board technique was developed. With this new technique, the diver holds on to the manta-board with one arm; consequently, the board is referred to as a single-armed manta-board (sam-board). The sam-board proved inexpensive and highly maneuverable, allowing the divers to freely collect samples or record information. Through some experimenting with the board and changing some of the variables, such as rope lengths, towing speeds, etc., a highly efficient towing method can be achieved. Preplanning and strict diving safety procedures must, however, be implemented to assure efficiency. This paper presents the materials, guidelines for board construction, equipment, and preplanning and diving safety procedures necessary for the sam-board towing operation

Kinetic step bunching during surface growth

We study the step bunching kinetic instability in a growing crystal surface characterized by anisotropic diffusion. The instability is due to the interplay between the elastic interactions and the alternation of step parameters. This instability is predicted to occur on a vicinal semiconductor surface Si(001) or Ge(001) during epitaxial growth. The maximal growth rate of the step bunching increases like $F^{4}$, where $F$ is the deposition flux. Our results are complemented with numerical simulations which reveals a coarsening behavior on the long time for the nonlinear step dynamics.Comment: 4 pages, 6 figures, submitted to PR

Ceramic composition at Chalcolithic Shiqmim, northern Negev desert, Israel: investigating technology and provenance using thin section petrography, instrumental geochemistry and calcareous nannofossils

Technological innovations in ceramic production and other crafts are hallmarks of the Chalcolithic period (4500–3600 BCE) in the southern Levant, but details of manufacturing traditions have not been fully investigated using the range of analytical methods currently available. This paper presents results of a compositional study of 51 sherds of ceramic churns and other pottery types from the Chalcolithic site of Shiqmim in the northern Negev desert. By applying complementary thin section petrography, instrumental geochemistry and calcareous nannofossil analyses, connections between the raw materials, clay paste recipes and vessel forms of the selected ceramic samples are explored and documented. The study indicates that steps in ceramic manufacturing can be related to both technological choices and local geology. Detailed reporting of the resulting data facilitates future comparative ceramic compositional research that is needed as a basis for testable regional syntheses and to better resolve networks of trade/exchange and social group movement

Metallacyclobutane Chemistry

This thesis describes the preparation, characterisation, and reactivity of a new class of platinacyclobutane complexes, containing a hydroxyl or ester functionality. The monomeric compounds are prepared by the reaction of Zeise\u27s dimer with the appropriate cyclopropane derivative and subsequent addition of pyridine.;Owing to the presence of the hydroxyl group, these complexes have been shown to interact with the shift reagent, Eu(fod)(,3), so as to greatly simplify their (\u271)H-N.M.R. spectra. Using the results obtained from this study and the equation of Karplus, comparisons are drawn between ring conformations in the solid state and solution which indicate significant puckering of these complexes in solution.;A novel ring expansion reaction is presented by which platinacyclopentanes are prepared by solvolysis of the platinacyclobutylcarbinyl esters, under mild conditions. Platinacyclopentanes are the exclusive products, identified by their (\u2713)C and (\u271)H N.M.R. spectra. The mechanism by which this rearrangement proceeds was studied by kinetics as well as suitable (\u2713)C and (\u272)H labelling studies in the absence and presence of added pyridine. The results indicate one overall mechanism with a step dependent on pyridine concentration.;The reactions of Zeise\u27s dimer with bicyclo{lcub}2.1.0{rcub}pentane and quadricyclane, in acetone, are shown to give cyclopentene and norbornadiene (NBD) and {lcub}PtCl(,2)((mu)-Cl)(,2)(cyclopentene)(,2){rcub} and {lcub}PtCl(,2)(NBD){rcub} as the respective products.;1-Methylcyclopropyl carbinol and 2-cyclopropyl-2-propyl-p-nitrobenzoate react cleanly, in acetone, with {lcub}Rh(,2)Cl(,2)(CO)(,4){rcub} to gibe 1-methylcyclobutanol and 5-chloro-2-pentene, respectively. The mechanism of the first of these was investigated by kinetics and (\u272)H labelling studies while a novel carboxylate bridged rhodium dimer was obtained in the latter. Possible mechanisms for these rearrangements are presented which may involve metallacycle intermediates

Principalities and powers : an investigation of cosmic conflict within the context of human life

https://place.asburyseminary.edu/ecommonsatsdissertations/2017/thumbnail.jp

Effect of step stiffness and diffusion anisotropy on the meandering of a growing vicinal surface

We study the step meandering instability on a surface characterized by the alternation of terraces with different properties, as in the case of Si(001). The interplay between diffusion anisotropy and step stiffness induces a finite wavelength instability corresponding to a meandering mode. The instability sets in beyond a threshold value which depends on the relative magnitudes of the destabilizing flux and the stabilizing stiffness difference. The meander dynamics is governed by the conserved Kuramoto-Sivashinsky equation, which display spatiotemporal coarsening.Comment: 4 pages, 3 figures, submitted to Phys. Rev. Lett. (February 2006