Genetic stratigraphy of the Fort Scott Limestone (Pennsylvanian, Desmoinesian), southeastern Kansas

The punctuated aggradational cycle (PAC) approach of Anderson and Goodwin (1980) and transgressive-regressive units of Busch and Rollins (1984) were used to differentiate small-scale [1-3 m (3.3-10 ft) thick] genetic units in strata of the 9+-m-thick (30+-ft-thick) Fort Scott Limestone (Marmaton Group, Desmoinesian Stage, Middle Pennsylvanian Series) of southeastern Kansas, northeastern Oklahoma, and west-central Missouri. Nine outcrop exposures were observed directly, and information from 20 stratigraphic sections was taken from the literature. The lithologic sequence of the Marmaton Group is similar to cyclothems of the Illinois basin, and thus the genesis of coal is important. Many recent studies have interpreted midcontinent sedimentary strata using Heckel's (1977) model of the basic Kansas cyclothem, which emphasizes a lithostratigraphic approach. The PAC hypothesis is a genetic approach that provides a chronostratigraphic framework for interpreting the strata, reveals a more detailed sea-level history compared to the cyclothem approach, and provides more details for inferring the paleotopography, structural controls, paleogeography and paleoclimatology of the interval. We have identified four (possibly five) sixth-order cycles (Brett et al., 1990) or PACs (Goodwin and Anderson, 1985), which include as many flooding surfaces, in an interval previously interpreted as one cyclothem [the upper Fort Scott cyclothem of Knight (1985)]. These PACs can be traced and correlated throughout the outcrop area, a distance of over 300 km (190 mi), and are similar to small-scale cycles recognized by others in the Triassic of Italy and in the Silurian-Devonian sequence of New York. Recognition and correlation of sixth-order cycles (Brett et al., 1990) or PACs is of value to sedimentary modelers because the more detailed relative sea-level curves and finer scale stratigraphic details will result in better defined parameters, such as sedimentation rates, magnitudes of sea-level changes, and climatic perturbations

Genetic stratigraphy of the Fort Scott Limestone (Pennsylvanian, Desmoinesian), southeastern Kansas

The punctuated aggradational cycle (PAC) approach of Anderson and Goodwin (1980) and transgressive-regressive units of Busch and Rollins (1984) were used to differentiate small-scale [1-3 m (3.3-10 ft) thick] genetic units in strata of the 9+-m-thick (30+-ft-thick) Fort Scott Limestone (Marmaton Group, Desmoinesian Stage, Middle Pennsylvanian Series) of southeastern Kansas, northeastern Oklahoma, and west-central Missouri. Nine outcrop exposures were observed directly, and information from 20 stratigraphic sections was taken from the literature. The lithologic sequence of the Marmaton Group is similar to cyclothems of the Illinois basin, and thus the genesis of coal is important. Many recent studies have interpreted midcontinent sedimentary strata using Heckel's (1977) model of the basic Kansas cyclothem, which emphasizes a lithostratigraphic approach. The PAC hypothesis is a genetic approach that provides a chronostratigraphic framework for interpreting the strata, reveals a more detailed sea-level history compared to the cyclothem approach, and provides more details for inferring the paleotopography, structural controls, paleogeography and paleoclimatology of the interval. We have identified four (possibly five) sixth-order cycles (Brett et al., 1990) or PACs (Goodwin and Anderson, 1985), which include as many flooding surfaces, in an interval previously interpreted as one cyclothem [the upper Fort Scott cyclothem of Knight (1985)]. These PACs can be traced and correlated throughout the outcrop area, a distance of over 300 km (190 mi), and are similar to small-scale cycles recognized by others in the Triassic of Italy and in the Silurian-Devonian sequence of New York. Recognition and correlation of sixth-order cycles (Brett et al., 1990) or PACs is of value to sedimentary modelers because the more detailed relative sea-level curves and finer scale stratigraphic details will result in better defined parameters, such as sedimentation rates, magnitudes of sea-level changes, and climatic perturbations

The digital data processing concepts of the LOFT mission

The Large Observatory for X-ray Timing (LOFT) is one of the five mission candidates that were considered by ESA for an M3 mission (with a launch opportunity in 2022 - 2024). LOFT features two instruments: the Large Area Detector (LAD) and the Wide Field Monitor (WFM). The LAD is a 10 m 2 -class instrument with approximately 15 times the collecting area of the largest timing mission so far (RXTE) for the first time combined with CCD-class spectral resolution. The WFM will continuously monitor the sky and recognise changes in source states, detect transient and bursting phenomena and will allow the mission to respond to this. Observing the brightest X-ray sources with the effective area of the LAD leads to enormous data rates that need to be processed on several levels, filtered and compressed in real-time already on board. The WFM data processing on the other hand puts rather low constraints on the data rate but requires algorithms to find the photon interaction location on the detector and then to deconvolve the detector image in order to obtain the sky coordinates of observed transient sources. In the following, we want to give an overview of the data handling concepts that were developed during the study phase.Comment: Proc. SPIE 9144, Space Telescopes and Instrumentation 2014: Ultraviolet to Gamma Ray, 91446

Modeling of MnS precipitation during the crystallization of grain oriented silicon steel

The process of manganese sulfide formation in the course of grain-oriented silicon steel solidification process is described in the paper. Fine dispersive MnS inclusions are grain growth inhibitors and apart from AlN inclusions they contribute to the formation of a privileged texture, i.e. Goss texture. A computer simulation of a high-silicon steel ingot solidification with the use of author’s software has been performed. Ueshima model was adapted for simulating the 3 % Si steel ingot solidification. The calculations accounted for the back diffusion effect according to Wołczyński equation. The computer simulation results are presented in the form of plots representing the process of steel components segregation in a solidifying ingot and curves illustrating the inclusion separation process

Modelling of non-metallic particles motion process in foundry alloys

The behaviour of non-metallic particles in the selected composites was analysed, in the current study. The calculations of particles floating in liquids differing in viscosity were performed. Simulations based on the Stokes equation were made for spherical SiC particles and additionally the particle size influence on Reynolds number was analysed.The movement of the particles in the liquid metal matrix is strictly connected with the agglomerate formation problem.Some of collisions between non-metallic particles lead to a permanent connection between them. Creation of the two spherical particles and a metallic phase system generates the adhesion force. It was found that the adhesion force mainly depends on the surface tension of the liquid alloy and radius of non-metallic particles

Modelling of the crystallization front – particles interactions in ZnAl/(SiC)p composites

The presented work focuses on solid particle interactions with the moving crystallization front during a solidification of the metal matrix composite. The current analyses were made for silicon carbide particles and ZnAl alloy with different additions of aluminium. It was found, that the chemical composition of the metal matrix influences the behaviour of SiC particles. At the same time calculations of the forces acting on a single particle near the crystallization front were performed. For each alloy type the critical conditions that determine whether particle will be absorbed or pushed, were specified

A 0535+26 in the August/September 2005 outburst observed by RXTE and INTEGRAL

In this Letter we present results from INTEGRAL and RXTE observations of the spectral and timing behavior of the High Mass X-ray Binary A 0535+26 during its August/September 2005 normal (type I) outburst with an average flux F(5-100keV)~400mCrab. The search for cyclotron resonance scattering features (fundamental and harmonic) is one major focus of the paper. Our analysis is based on data from INTEGRAL and RXTE Target of Opportunity Observations performed during the outburst. The pulse period is determined. X-ray pulse profiles in different energy ranges are analyzed. The broad band INTEGRAL and RXTE pulse phase averaged X-ray spectra are studied. The evolution of the fundamental cyclotron line at different luminosities is analyzed. The pulse period P is measured to be 103.39315(5)s at MJD 53614.5137. Two absorption features are detected in the phase averaged spectra at E_1~45keV and E_2~100keV. These can be interpreted as the fundamental cyclotron resonance scattering feature and its first harmonic and therefore the magnetic field can be estimated to be B~4x10^12G.Comment: 4 pages, 5 figures, accepted for publication in A&A Letter

Peculiar outburst of A 0535+26 observed with INTEGRAL, RXTE and Suzaku

A normal outburst of the Be/X-ray binary system A0535+26 has taken place in August 2009. It is the fourth in a series of normal outbursts that have occured around the periastron passage of the source, but is unusual by starting at an earlier orbital phase and by presenting a peculiar double-peaked light curve. A first "flare" (lasting about 9 days from MJD 55043 on) reached a flux of 440 mCrab. The flux then decreased to less than 220 mCrab, and increased again reaching 440 mCrab around the periastron at MJD 55057. Target of Opportunity observations have been performed with INTEGRAL, RXTE and Suzaku. First results of these observations are presented, with special emphasis on the cyclotron lines present in the X-ray spectrum of the source, as well as in the pulse period and energy dependent pulse profiles of the source.Comment: 6 pages, Accepted for publication on PoS, Proceedings of "The Extreme sky: Sampling the Universe above 10 keV", held in Otranto (Italy) in October 200

No apparent accretion mode changes detected in Cen X-3

The presence of two distinct spectral states has previously been reported for Cen X-3 on the basis of RXTE/ASM observations. Triggered by this result, we investigated the spectral properties of the source using the larger amount of X-ray data now available with the aim to clarify and interpret the reported behavior. To check the reported results we used the same data set and followed the same analysis procedures as in the work reporting the two spectral states. Additionally, we repeated the analysis using the enlarged data sample including the newest RXTE/ASM observations as well as the data from the MAXI monitor and from the INTEGRAL/JEM-X and ISGRI instruments. We could not confirm the reported presence of the two spectral states in Cen X-3 either inComment: 4 pages, 6 figures, article is accepted for Astronomy & Astrophysic