Effects of Ionospheric Asymmetry on Electron Density Standard Inversion Algorithm Applicable to Radio Occultation (RO) Data Using Best-suited Ionospheric Model

The "Onion-peeling" algorithm is a very common technique used to invert Radio Occultation (RO) data in the ionosphere. Because of the implicit assumption of spherical symmetry for the electron density (Ne) distribution in the ionosphere, the standard Onion-peeling algorithm could give erroneous concentration values in the retrieved electron density vertical profile Ne(h). In particular, this happens when strong horizontal ionospheric electron density gradients are present, like for example in the Equatorial Ionization Anomaly (EIA) region during high solar activity periods. Using simulated RO Total Electron Content (TEC) data computed by means of the best-suited ionospheric model and ideal RO geometries, we evaluated the asymmetry level index for quasi-horizontal TEC observations. This asymmetry index is based on the Ne variations that a signal may experience along its ray-path (satellite to satellite link) during a RO event. The index is strictly dependent on RO geometry and azimuth of the occultation plane and is able to provide us indication of the errors (in particular those concerning the peak electron density NmF2 and the vertical TEC) expected in the retrieval of Ne(h) using standard Onion-peeling algorithm. On the basis of the outcomes of our work, and using best-suited ionospheric model, we will try to investigate the possibility to predict the ionospheric asymmetry expected for the particular RO geometry considered. We could also try to evaluate, in advance, its impact on the inverted electron density profile, providing an indication of the product qualit

Crystal nucleation mechanism in melts of short polymer chains under quiescent conditions and under shear flow

We present a molecular dynamics simulation study of crystal nucleation from undercooled melts of n-alkanes, and we identify the molecular mechanism of homogeneous crystal nucleation under quiescent conditions and under shear flow. We compare results for n-eicosane(C20) and n-pentacontahectane(C150), i.e. one system below the entanglement length and one above. Under quiescent conditions, we observe that entanglement does not have an effect on the nucleation mechanism. For both chain lengths, the chains first align and then straighten locally. Then the local density increases and finally positional ordering sets in. At low shear rates the nucleation mechanism is the same as under quiescent conditions, while at high shear rates the chains align and straighten at the same time. We report on the effects of shear rate and temperature on the nucleation rates and estimate the critical shear rates, beyond which the nucleation rates increase with the shear rate. We show that the viscosity of the system is not affected by the crystalline nuclei.Comment: 9 page

The Early Crystal Nucleation Process in Hard Spheres shows Synchronised Ordering and Densification

We investigate the early part of the crystal nucleation process in the hard sphere fluid using data produced by computer simulation. We find that hexagonal order manifests continuously in the overcompressed liquid, beginning approximately one diffusion time before the appearance of the first `solid-like' particle of the nucleating cluster, and that a collective influx of particles towards the nucleation site occurs simultaneously to the ordering process: the density increases leading to nucleation are generated by the same individual particle displacements as the increases in order. We rule out the presence of qualitative differences in the early nucleation process between medium and low overcompressions, and also provide evidence against any separation of translational and orientational order on the relevant lengthscales

Efektivitas Peraturan Gubernur Tentang Standar Operasional Prosedur (Sop) Administrasi Pemerintahan Di Pemerintah Di Pemerintah Daerah Provinsi Sulawesi Tengah

The purpose of this study was to determine how the effectiveness of Governor Regulation on Standard Operating Procedures (SOP) Administrative Governance in Central Sulawesi Provincial Government, who studied based on theoretical models measure the effectiveness of Duncan by using variables: 1). Achievement, 2). Integration, 3). Adaptation. This type of research used qualitative decision-informants purposively and the number of informants as much as 5 people with data collection techniques, 1). Observation, 2). Interviews, 3). Documentation. Catalysts data using Miles and Huberman opinion. Results is Indicates that the preparation of Standard Operating Procedures (SOP) Administration In Central Sulawesi Provincial Government does not operate effectively under Regulation Governor of Central Sulawesi Central No. 17 Year 2012 on Standard Operating Procedures in the Government of Central Sulawesi province. Judging from the three measures of effectiveness proposed by Duncan, who runs a good criterion, namely adaptation. While the criteria have not been running well in the preparation of Standard Operating Procedures (SOP) Administration in the Government of Central Sulawesi province, namely Achievement and Integration because of ineffective socialization preparation of Standard Operating Procedures Administration that resulted in delayed ratification of the Standard Operating Procedure Administration, which should be legalized in 2016