The Role of Phase Space in Complex Fragment Emission from Low to Intermediate Energies

The experimental emission probabilities of complex fragments by low energy compound nuclei and their dependence upon energy and atomic number are compared to the transition state rates. Intermediate-mass-fragment multiplicity distributions for a variety of reactions at intermediate energies are shown to be binomial and thus reducible at all measured transverse energies. From these distributions a single binary event probability can be extracted which has a thermal dependence. A strong thermal signature is also found in the charge distributions. The n-fold charge distributions are reducible to the 1-fold charge distributions through a simple scaling dictated by fold number and charge conservation.Comment: 15 pages, TeX type, psfig, also available at http://csa5.lbl.gov/moretto/ps/brazil.ps, to appear in Proceedings of the 1st International Conference on Nuclear Dynamics at Long and Short Distances, April 8-12, 1996, Angra dos Reis, Brazi

Nonlinear force-free field modeling of a solar active region using SDO/HMI and SOLIS/VSM data

We use SDO/HMI and SOLIS/VSM photospheric magnetic field measurements to model the force-free coronal field above a solar active region, assuming magnetic forces to dominate. We take measurement uncertainties caused by, e.g., noise and the particular inversion technique into account. After searching for the optimum modeling parameters for the particular data sets, we compare the resulting nonlinear force-free model fields. We show the degree of agreement of the coronal field reconstructions from the different data sources by comparing the relative free energy content, the vertical distribution of the magnetic pressure and the vertically integrated current density. Though the longitudinal and transverse magnetic flux measured by the VSM and HMI is clearly different, we find considerable similarities in the modeled fields. This indicates the robustness of the algorithm we use to calculate the nonlinear force-free fields against differences and deficiencies of the photospheric vector maps used as an input. We also depict how much the absolute values of the total force-free, virial and the free magnetic energy differ and how the orientation of the longitudinal and transverse components of the HMI- and VSM-based model volumes compares to each other.Comment: 9 pages, 5 figure

Spin wave amplification through superradiance

Superradiance is a phenomenon of multiple facets that occurs in classical and quantum physics under extreme conditions. Here we present its manifestation in spin waves under an easily realized condition. We show that an interface between a current-free (normal) ferromagnetic (FM) region and a current-flow (pumped) FM region can be a spin wave super-mirror whose reflection coefficient is larger than 1. The super-reflection is the consequence of current-induced spectrum inversion where phase and group velocities of spin waves are in the opposite directions. An incident spin wave activates a backward propagating refractive wave inside pumped FM region. The refractive spin wave re-enters the normal FM region to constructively interfere with the reflective wave. It appears that the pumped FM region coherently emits reflective waves, leading to a super-reflection. The process resembles superradiance of a spinning black hole through the Hawking radiation process, or Dicke superradiance of cavity photons inside population inverted media

Effect of propionate on the production of natamycin with Streptomyces gilvosporeus XM-172

This study described the influence of feeding short-chain fatty acids and alcohols on natamycin production in the glucose basal medium, produced by Streptomyces gilvosporeus XM-172. The highest natamycin production was obtained with feeding propionate as compared to other precursors. The optimal propionate concentration and feeding time were 6 g L-1 and early log phase, respectively. This optimal propionate feeding strategy led to a natamycin production of 6.72 g L-1, which was nearly 85% higher than that of the control. It was firstly revealed that propionate could greatly promote natamycin biosynthesis by S. gilvosporeus.Key words: Precursor, propionate, natamycin production, Streptomyces gilvosporeus XM-172

Tunnelling Effect and Hawking Radiation from a Vaidya Black Hole

In this paper, we extend Parikh' work to the non-stationary black hole. As an example of the non-stationary black hole, we study the tunnelling effect and Hawking radiation from a Vaidya black hole whose Bondi mass is identical to its mass parameter. We view Hawking radiation as a tunnelling process across the event horizon and calculate the tunnelling probability. We find that the result is different from Parikh's work because $\frac{dr_{H}}{dv}$ is the function of Bondi mass m(v)

Graph based cross-shape recognition for palm diagnosis

Author name used in this publication: David ZhangBiometrics Research Centre, Department of ComputingVersion of RecordPublishe

Dynamic Time-history Analysis on Wind-induced Response of Light-weight Roof System

Severe damage to light-weight roof system occur when exposed to strong wind loading. Damage investigations and wind load-bearing capacity tests of light-weight roof system reveal that the connection damage of roof sheeting and fastener is the most serious. Wind pressure distributions on the roof of gabled steel frame measured in a wind tunnel are described. Secondly, illustrated by the example of the classic standing-lock roof system, the wind-induced forces for the concealed clips estimated by the building code and time-history analysis based on wind tunnel test, respectively, are compared. The results indicate that the uniform gust factor used in the building code for the wind-induced forces for the clips cannot guarantee that all the clips have strong strength in an actual wind load. Any of wind-induced forces for the clips varies in a relative large rang affected by the fluctuation and spatial correlation of wind pressure. The building code generally provided inconsistent estimations of the wind-induced forces of the clips and the true loaded wind area should be evaluated by considering the characteristics of the spatial correlation of wind pressures relative to the structural framing

Integration of DSM and SPH to Model Tailings Dam Failure Run-Out Slurry Routing Across 3D Real Terrain

This is the final version of the article. Available from MDPI via the DOI in this record.Tailings dam failure accidents occur frequently, causing substantial damage and loss of human and animal life. The prediction of run-out tailings slurry routing following dam failures is of great significance for disaster prevention and mitigation. Using satellite remote sensing digital surface model (DSM) data, tailings pond parameters and the advanced meshless smoothed particle hydrodynamics (SPH) method, a 3D real-scale numerical modelling method was adopted to study the run-out tailings slurry routing across real downstream terrains that have and have not been affected by dam failures. Three case studies, including a physical modelling experiment, the 2015 Brazil Fundão tailings dam failure accident and an operating high-risk tailings pond in China, were carried out. The physical modelling experiment and the known consequences were successfully modeled and validated using the SPH method. This and the other experiments showed that the run-out tailings slurry would be tremendously destructive in the early stages of dam failure, and emergency response time would be extremely short if the dam collapses at its full designed capacity. The results could provide evidence for disaster prevention and mitigation engineering, emergency management plan optimization, and the development of more responsible site plans and sustainable site designs. However, improvements such as rheological model selection, terrain data quality, computing efficiency and land surface roughness need to be made for future studies. SPH numerical modelling is a powerful and advanced technique that is recommended for hazard assessment and the sustainable design of tailings dam facilities globally.This research was funded by the National Natural Science Foundation of China (grant number 51774045), National Key R&D Program of China (grant number 2017YFC0804600), China Scholarship Council (grant number 201706460051) and Natural Science Foundation project of Chongqing Science and Technology Commission (grant number cstc2016jcyjA0319 and cstc2018jcyjAX0231)