Recent results on PHENIX longitudinal asymmetry measurements

The spin structure of proton has been a long-standing open question for the last decades. Polarized DIS and SIDIS experiments have been the Explorer of the field and providing us the knowledge the part of substructure of the proton spin by its subcomponents. In contrast to well-measured valence quark contribution to the proton spin, polarization of gluons and sea quarks still remain with a large uncertainty. PHENIX experiment has been providing various asymmetry data to introduce new constraints to the proton spin structure, particularly gluon and sea quark polarization in proton spin using the world highest-energy polarized protonproton collider, RHIC. In this report, the latest gluon polarization measurements in PHENIX through various observables are presented. Also preliminary results of W-boson production to measure the sea quark polarization in both central and forward rapidity are presented

Polarization Enhancement of terahertz radiation generated by intrinsic Josephson junctions in a truncated edge square Bi_{2}Sr_{2}CaCu_{2}O_{8+{\delta}} mesa

In this study, we investigated the terahertz radiation from a truncated edge square mesa structure made from a superconducting Bi_{2}Sr_{2}CaCu_{2}O_{8+{\delta}} . Using a commercial software, the polarization characteristics were determined, and introduced, while accounting for the skin effect. The axial ratio was enhanced in the simulation by performing a parametric study on the design.Comment: Proceedings of the 28th International Symposium on Superconductivity, ISS 2015, November 16-18, 2015, Tokyo, Japa

Grain size dependence of barchan dune dynamics

The dependence of the barchan dune dynamics on the size of the grains involved is investigated experimentally. Downsized barchan dune slices are observed in a narrow water flow tube. The relaxation time from an initial symmetric triangular heap towards an asymmetric shape attractor increases with dune mass and decreases with grain size. The dune velocity increases with grain size. In contrast, the velocity scaling and the shape of the barchan dune is independent of the size of the grains