Etudes on iurids, IX. Further analysis of a rare species \u3cem\u3eProtoiurus kadleci\u3c/em\u3e (Scorpiones: Iuridae) from Turkey, based on adult males

Additional material of a rare scorpion species Protoiurus kadleci (Kovařík et al., 2010) from Turkey (Antalya Province) was examined, in particular, sexually mature males. New information is presented on the morphometric differences between adult and subadult males of this species, and on the differences between P. kadleci and other species of Protoiurus. An updated diagnosis of P. kadleci is presented, as well as updated key to six species of Protoiurus, and a map showing all known localities

Planetary migration in evolving planetesimals discs

In the current paper, we further improved the model for the migration of planets introduced in Del Popolo et al. (2001) and extended to time-dependent planetesimal accretion disks in Del Popolo and Eksi (2002). In the current study, the assumption of Del Popolo and Eksi (2002), that the surface density in planetesimals is proportional to that of gas, is released. In order to obtain the evolution of planetesimal density, we use a method developed in Stepinski and Valageas (1997) which is able to simultaneously follow the evolution of gas and solid particles for up to 10^7 yrs. Then, the disk model is coupled to migration model introduced in Del Popolo et al. (2001) in order to obtain the migration rate of the planet in the planetesimal. We find that the properties of solids known to exist in protoplanetary systems, together with reasonable density profiles for the disk, lead to a characteristic radius in the range 0.03-0.2 AU for the final semi-major axis of the giant planet.Comment: IJMP A in prin

On the nature of gravitational forces

In this paper I show how the statistics of the gravitational field is changed when the system is characterized by a non-uniform distribution of particles. I show how the distribution functions W(dF/dt) giving the joint probability that a test particle is subject to a force F and an associated rate of change of F given by dF/dt, are modified by inhomogeneity. Then I calculate the first moment of dF/dt to study the effects of inhomogenity on dynamical friction. Finally I test, by N-Body simulations, that the theoretical W(F) and dF/dt describes correctly the experimental data and I find that the stochastic force distribution obtained for the evolved system is in good agreement with theory. Moreover, I find that in an inhomogeneous background the friction force is actually enhanced relative to the homogeneous case

Global sensitivity analysis of stochastic computer models with joint metamodels

The global sensitivity analysis method used to quantify the influence of uncertain input variables on the variability in numerical model responses has already been applied to deterministic computer codes; deterministic means here that the same set of input variables gives always the same output value. This paper proposes a global sensitivity analysis methodology for stochastic computer codes, for which the result of each code run is itself random. The framework of the joint modeling of the mean and dispersion of heteroscedastic data is used. To deal with the complexity of computer experiment outputs, nonparametric joint models are discussed and a new Gaussian process-based joint model is proposed. The relevance of these models is analyzed based upon two case studies. Results show that the joint modeling approach yields accurate sensitivity index estimatiors even when heteroscedasticity is strong

Outcomes from elective colorectal cancer surgery during the SARS-CoV-2 pandemic

This study aimed to describe the change in surgical practice and the impact of SARS-CoV-2 on mortality after surgical resection of colorectal cancer during the initial phases of the SARS-CoV-2 pandemic

Investigation of availability of raw perlite in refractory building material production

Perlite having rich reserves in Turkey is basic industrial raw material in line with sustainable development objectives. In recent years due to the thermal insulation properties expanded perlite has attracted the attention of researchers. It is started to use in some construction areas. Binder material is used to shape in the manufacturing of refractory bricks. Desired material was sintered at high temperature. In this study, perlite between 75-600 µm particle size was subjected to heat treatment at different temperatures and investigated to use in refractory construction materials production. Perlite grains clinging to each other engage a smooth shape. Gypsum is used as an activator in different proportions to achieve this objective. The samples were subjected to heat treatment at 1050-1200 °C for 30 minutes. In the 5% gypsum mixture highest compressive strength at 1150 °C was calculated as 47 MPa. Unit volume weight is considered as 1.95 g/cm3, water absorption by weight is determined as 0.30%. Superficial abrasion loss was determined to be 20 mm. Degree of porosity is calculated as 15%. Compactness was found to be 85%. Furthermore in the results of experiment of freezing of the obtained products was not found any damage or any strength loss. © 2018 Ergün Yesilyurt, Osman Simsek, Ahmet Bilgil

Distribution and population density of the ghost crab, Ocypode cursor (Linneaus, 1758) in Yumurtalik Beach, Turkey

The distribution and population density of the ghost crab, Ocypode cursor were studied in Yumurtalik Beach, Turkey during summer, 2009. Burrow densities of ghost crab were measured at three beach zones in relation to the Reference Datum (RD) with middle heights of 2, 4, and 9 m, which were located at medi-olittoral, supra-littoral, and sub-terrestrial fringe, respectively. Generally, individuals occurred above 1 m in height in relation to RD and peaked between 2 and 4 m. A range from 0 to 4.2 burrows/m2 was obtained, and the total number of crabs on this beach (approximately is 2256 km2) ranging from 18.99 burrows/m2 to 56.41 burrows/m2. Significant differences in the mean burrow density were found among three zones. Low densities were recorded in the sub-terrestrial zone in September and peak density in the supralittoral zone in August. In general crabs followed a clumped dispersion on Yumurtalik beach. In total 986 burrow diameters were measured where diameter ranged from 3 to 97.8 mm. The results provided evidence that Yumurtalik Beach can provide suitable habitats for O. cursor population. Ocypode cursor is not vulnerable to the anthropogenic disturbances and environmental alterations found at Yumurtalik Beach