Solar System: Sifting through the debris

A quadrillion previously unnoticed small bodies beyond Neptune have been spotted as they dimmed X-rays from a distant source. Models of the dynamics of debris in the Solar System's suburbs must now be reworked.Comment: 3 pages, 1 figure; Nature News and Views on Chang et al. 2006, Nature, 442, 660-66

Comments on "The Role of the Central Asian Mountains on the Midwinter Suppression of North Pacific Storminess" - Reply

We thank Chang and Lin for their thoughtful and constructive comments on our study (Park et al. 2010). In Park et al. (2010), we did not explicitly state that the topography-forced stationary waves are the direct cause for the reduced downstream transient eddy kinetic energy (EKE). The response of stationary waves to topography may saturate even with a relatively small mountain (Cook and Held 1992); furthermore, their magnitudes are much smaller than thermally forced stationary waves (Chang 2009; Held et al. 2002). Instead, we suggest that quasistationary waves generated by the central Asian mountains may strongly affect North Pacific storminess by changing the year-to-year variability of westerly winds over the eastern Eurasian continent. Observational analyses indicate that the midwinter suppression of North Pacific storminess does not occur every year. Some years experience stronger and more meridionally confined zonal winds over the western North Pacific, leading to stronger midwinter suppression (Harnik and Chang 2004; Nakamura and Sampe 2002)

Weighted Radon transforms for which the Chang approximate inversion formula is precise

We describe all weighted Radon transforms on the plane for which the Chang approximate inversion formula is precise. Some subsequent results, including the Cormack type inversion for these transforms, are also given

Effect of Particulate Matters from Shipping Activities around Si Racha Bay – Si Chang Island

Shipping activities around Si Chang harbor including tapioca flour pellet, cement, fertilizer, coal, and so on caused the deposition of particulate matters into marine environment and dispersion of fine particles to Si Racha and Si Chang coastal line. All particles were monitored to identify the emission sources by Scanning Electron Microscope (SEM). Chemical compositions were analyzed for the amounts of heavy metals adsorbed on the collected particulate matter by ICP-AES. Total Suspended Particulate (TSP) and Particulate Matter less than 10 micrometers (PM10) were collected at the coast line of Queen Savangwadhana Hospital at Si Racha from April to July, 2008. The amounts of TSP varied from 0.0239-0.0950 μg/m3 with average value at 0.0726±0.0191 μg/m3. The concentrations of PM10 varied from 0.0142-0.0482 μg/m3 with average value at 0.0195±0.01 μg/m3. The microscopic structures of TSP provided the difference in shape and dimensions from 0.1 to greater than 100 micrometers while the microstructures of PM10 presented the spherical shape. The dimensions and shapes of all particulate matter samples were mostly similar to reference particulate of tapioca flour and fertilizer particles. The particulate with greater than 100 micrometers which provided similar shape to cement does not be seen in all samples. It could be summarized that the light particle of tapioca flour were dominated in the particulate matters dispersion from shipping activities at Si Chang harbor. The weighted mean concentrations (WMC ± WSD) of Zn, Ni, Cu, Hg, Pb and Se were 0.0476±0.0831, 0.0010±1.29 x 10-4, 0.0071±4.96 x 10-5, 0.0007±1.32 x 10-7, 0.0006±1.78 x 10-7 and 0.0006±1.53 x 10-7 ng/g.m3, respectively for TSP and 0.0119±1.46 x 10-4, 0.0005±4.73 x 10-7, 0.0024±1.31 x 10-5, 0.0001±5.41 x 10-9, 0.0004±1.55 x 10-7 and 0.0004±3.45 x 10-8 ng/g.m3, respectively for PM10

Diffusion coefficient and shear viscosity of rigid water models

We report the diffusion coefficient and viscosity of popular rigid water models: Two non polarizable ones (SPC/E with 3 sites, and TIP4P/2005 with 4 sites) and a polarizable one (Dang-Chang, 4 sites). We exploit the dependence of the diffusion coefficient on the system size [Yeh and Hummer, J. Phys. Chem. B 108, 15873 (2004)] to obtain the size-independent value. This also provides an estimate of the viscosity of all water models, which we compare to the Green-Kubo result. In all cases, a good agreement is found. The TIP4P/2005 model is in better agreement with the experimental data for both diffusion and viscosity. The SPC/E and Dang-Chang water overestimate the diffusion coefficient and underestimate the viscosity.Comment: 10 pages, 2 figures. To be published in J. Phys.: Condens. Matte

Analytical and scale model research aimed at improved hangglider design

Research consisted of a theoretical analysis which attempts to predict aerodynamic characteristics using lifting surface theory and finite-element structural analysis as well as an experimental investigation using 1/5 scale elastically similar models in the NASA Ames 2m x 3m (7' x 10') wind tunnel. Experimental data were compared with theoretical results in the development of a computer program which may be used in the design and evaluation of ultralight gliders