Modelling highway-traffic headway distributions using superstatistics

We study traffic clearance distributions (i.e., the instantaneous gap between successive vehicles) and time headway distributions by applying Beck and Cohen's superstatistics. We model the transition from free phase to congested phase with the increase of vehicle density as a transition from the Poisson statistics to that of the random matrix theory. We derive an analytic expression for the spacing distributions that interpolates from the Poisson distribution and Wigner's surmise and apply it to the distributions of the nett distance and time gaps among the succeeding cars at different densities of traffic flow. The obtained distribution fits the experimental results for single-vehicle data of the Dutch freeway A9 and the German freeway A5.Comment: 10 pages, 2 figure

Material growth and characterization for solid state devices

Manganese was used as the dopant for p-type InGaAs layers grown on semi-insulating (Fe-doped) and n-type (Sn-doped) InP substrates. Optical, electrical (Hall) and SIMS measurements were used to characterize the layers. Mn-diffusion into the substrate (during the growth of In GaAs) was observed only when Fe-doped substrates were used. Quaternary layers of two compositions corresponding to wavelengths (energy gaps) of approximated 1.52 micrometers were successfully grown at a constant temperature of 640 C and InP was grown in the temperature range of 640 C to 655 C. A study of the effect of pulses on the growth velocity of InP indicated no significant change as long as the average applied current was kept constant. A system for depositing films of Al2O3 by the pyrolysis of aluminum isopropoxide was designed and built. Deposited layers on Si were characterized with an ellipsometer and exhibited indices of refraction between 1.582 and 1.622 for films on the order of 3000 A thick. Undoped and p-type (Mn-doped) InGaAs epitaxial layers were also grown on Fe-doped InP substrates through windows in sputtered SiO2 (3200 A thick) layers

Spectral fluctuation properties of spherical nuclei

The spectral fluctuation properties of spherical nuclei are considered by use of NNSD statistic. With employing a generalized Brody distribution included Poisson, GOE and GUE limits and also MLE technique, the chaoticity parameters are estimated for sequences prepared by all the available empirical data. The ML-based estimated values and also KLD measures propose a non regular dynamic. Also, spherical odd-mass nuclei in the mass region, exhibit a slight deviation to the GUE spectral statistics rather than the GOE.Comment: 10 pages, 2 figure

Wealth distribution in an ancient Egyptian society

Modern excavations yielded a distribution of the house areas in the ancient Egyptian city Akhetaten, which was populated for a short period during the 14th century BC. Assuming that the house area is a measure of the wealth of its inhabitants allows us to make a comparison of the wealth distributions in ancient and modern societies

Physiotherapy Services in Bahrain: Are We Ready to Deal with a Disaster?

Background: Mitigating disaster-related disability by medical response is well established, and physiotherapy has been considered in the medium- to longterm care plan of the affected people. Purpose: To explore the sufficiency of the physiotherapy services in the Kingdom of Bahrain to meet the demands and needs ofthe population health and during a disaster, and to examine the relationship between the currently specialized physiotherapists (PTs) and their ability to cope with the cases associated with a disaster. Methods: Public data from three different governmental entities were analyzed regarding the population demographics and the number and specialties of the PTs. A market survey was conducted to collect data about the specializations needs. Results: There are 1.7 PTs for every 10,000 persons, and only 8% of the licensed PTs are specialized in orthopedics, neurology and pediatrics. About 30% of the PT workforce are non-Bahraini. Conclusion: The number of PTs per 10,000 persons in Bahrain is below the world’s average, and the current specializations of the licensed PTs may be insufficient to handle the complex cases of a disaster. Keywords: Physiotherapy, Rehabilitation, Disaster Response, Medical Response, Resilient Health Car