The design and construction of a Hohlraum spectral analyzer

Design and construction of Hohlraum spectral analyzer to aid in research of air pollutant

Study of fluid transients in closed conduits annual report no. 1

Atmospheric density effect on computation of earth satellite orbit

Redefinition of the Upper Pennsylvanian Virgilian Series in Kansas

The Virgilian Series was defined nearly 60 years ago to include those rocks lying between the Missourian Series and the base of the Permian System. In the type area in east-central Kansas, the Virgilian Series comprised the Douglas, Shawnee, and Wabaunsee Groups. In Kansas, the upper boundary of the Virgilian (Pennsylvanian-Permian boundary) was placed at the top of the Brownville Limestone Member on the basis of what was then believed to be a regional disconformity rather than on paleontological criteria. Recent advances in fusulinid and conodont biostratigraphy provide tentative criteria upon which to effect a change in the placement of the Virgilian-Permian boundary. It is now generally agreed that the base of the Permian System is approximated by the first occurrence of Pseudoschwagerina, an inflated schwagerinid. Furthermore, the Subcommission on Permian Stratigraphy has informally agreed that the base of the Permian should coincide with the first occurrence of the conodont species Streptognathodus barskovi. Inflated schwagerinids (Paraschwagerina kansasensis) first occur along with evolutionary changes in the Conodonta in the Neva Limestone of the Council Grove Group. Consequently, the Virgilian Series is herein redefined to include rocks present between the top of the Missourian Series and the base of the Neva Limestone. To increase compatibility between chronostratigraphic and lithostratigraphic nomenclature, the following changes are made: I) the Admire Group is redefined to include rocks between the base of the Onaga Shale and the base of the Neva Limestone; 2) the Admire is reassigned to the upper Virgilian Series; 3) the Neva Limestone is elevated to formational status; 4) the Grenola Limestone is redefined to include strata between the top of the Roca Shale and the base of the Neva Limestone; 5) the overlying Council Grove Group is redefined to include strata lying between the base of the Neva Limestone and the base of the Chase Group; and 6) regionally the base of the emended Council Grove Group marks the base of the Permian System. The emended Council Grove Group is lower Wolfcampian in age and is time equivalent with the Neal Ranch Formation of the west Texas type Wolfcampian

Redefinition of the Upper Pennsylvanian Virgilian Series in Kansas

The Virgilian Series was defined nearly 60 years ago to include those rocks lying between the Missourian Series and the base of the Permian System. In the type area in east-central Kansas, the Virgilian Series comprised the Douglas, Shawnee, and Wabaunsee Groups. In Kansas, the upper boundary of the Virgilian (Pennsylvanian-Permian boundary) was placed at the top of the Brownville Limestone Member on the basis of what was then believed to be a regional disconformity rather than on paleontological criteria. Recent advances in fusulinid and conodont biostratigraphy provide tentative criteria upon which to effect a change in the placement of the Virgilian-Permian boundary. It is now generally agreed that the base of the Permian System is approximated by the first occurrence of Pseudoschwagerina, an inflated schwagerinid. Furthermore, the Subcommission on Permian Stratigraphy has informally agreed that the base of the Permian should coincide with the first occurrence of the conodont species Streptognathodus barskovi. Inflated schwagerinids (Paraschwagerina kansasensis) first occur along with evolutionary changes in the Conodonta in the Neva Limestone of the Council Grove Group. Consequently, the Virgilian Series is herein redefined to include rocks present between the top of the Missourian Series and the base of the Neva Limestone. To increase compatibility between chronostratigraphic and lithostratigraphic nomenclature, the following changes are made: I) the Admire Group is redefined to include rocks between the base of the Onaga Shale and the base of the Neva Limestone; 2) the Admire is reassigned to the upper Virgilian Series; 3) the Neva Limestone is elevated to formational status; 4) the Grenola Limestone is redefined to include strata between the top of the Roca Shale and the base of the Neva Limestone; 5) the overlying Council Grove Group is redefined to include strata lying between the base of the Neva Limestone and the base of the Chase Group; and 6) regionally the base of the emended Council Grove Group marks the base of the Permian System. The emended Council Grove Group is lower Wolfcampian in age and is time equivalent with the Neal Ranch Formation of the west Texas type Wolfcampian

Proposed Repositioning of the Pennsylvanian-Permian Boundary in Kansas

The Pennsylvanian-Permian boundary in North America has not corresponded with the Carboniferous-Permian boundary in Europe for decades. To facilitate global correlations, an attempt is here made to suggest a possible solution to the dilemma by making the best possible correlation of the Kansas stratigraphic section with the recently proposed boundary location in the Russian type section. The Virgilian Stage (Upper Pennsylvanian) was defined nearly 60 years ago to include those rocks lying between the Missourian Stage and the base of the Permian System. In the type area in east-central Kansas, the Virgilian Stage comprised the Douglas, Shawnee, and Wabaunsee Groups. In Kansas, the Pennsylvanian-Permian boundary was placed eventually at the top of the Brownville Limestone Member on the basis of what was then believed to be a regional disconformity rather than on paleontological criteria. Recent advances in fusulinid and conodont biostratigraphy provide tentative criteria upon which to suggest a change in the placement of the Virgilian-Permian boundary. A Russian delegation formally proposed at the International Congress on the Permian System of the World held in Perm, U.S.S.R. (Russia) in August 1991 that the base of the Permian System be established at the base of the Asselian Stage at the approximate stratigraphic position of the first inflated fusulinids (Sphaeroschwagerina vulgaris-S. fusiformis). Inflated schwagerinids (Paraschwagerina kansasensis) first occur, along with evolutionary changes in conodonts, in the Neva Limestone Member of the Grenola Limestone (Council Grove Group). Thus, if we assume that inflated schwagerinids arose globally at about the same time, the Neva Limestone Member is the oldest definitive Permian in the United States midcontinent, as related to the newly proposed boundary in Russia and Kazakhstan. Consequently, we propose that the Virgilian Stage in Kansas include rocks between the top of the Missourian Stage and the base of the Neva Limestone Member

Robust Chauvenet Outlier Rejection

Sigma clipping is commonly used in astronomy for outlier rejection, but the number of standard deviations beyond which one should clip data from a sample ultimately depends on the size of the sample. Chauvenet rejection is one of the oldest, and simplest, ways to account for this, but, like sigma clipping, depends on the sample's mean and standard deviation, neither of which are robust quantities: Both are easily contaminated by the very outliers they are being used to reject. Many, more robust measures of central tendency, and of sample deviation, exist, but each has a tradeoff with precision. Here, we demonstrate that outlier rejection can be both very robust and very precise if decreasingly robust but increasingly precise techniques are applied in sequence. To this end, we present a variation on Chauvenet rejection that we call "robust" Chauvenet rejection (RCR), which uses three decreasingly robust/increasingly precise measures of central tendency, and four decreasingly robust/increasingly precise measures of sample deviation. We show this sequential approach to be very effective for a wide variety of contaminant types, even when a significant -- even dominant -- fraction of the sample is contaminated, and especially when the contaminants are strong. Furthermore, we have developed a bulk-rejection variant, to significantly decrease computing times, and RCR can be applied both to weighted data, and when fitting parameterized models to data. We present aperture photometry in a contaminated, crowded field as an example. RCR may be used by anyone at https://skynet.unc.edu/rcr, and source code is available there as well.Comment: 62 pages, 48 figures, 7 tables, accepted for publication in ApJ

Proposed Repositioning of the Pennsylvanian-Permian Boundary in Kansas

The Pennsylvanian-Permian boundary in North America has not corresponded with the Carboniferous-Permian boundary in Europe for decades. To facilitate global correlations, an attempt is here made to suggest a possible solution to the dilemma by making the best possible correlation of the Kansas stratigraphic section with the recently proposed boundary location in the Russian type section. The Virgilian Stage (Upper Pennsylvanian) was defined nearly 60 years ago to include those rocks lying between the Missourian Stage and the base of the Permian System. In the type area in east-central Kansas, the Virgilian Stage comprised the Douglas, Shawnee, and Wabaunsee Groups. In Kansas, the Pennsylvanian-Permian boundary was placed eventually at the top of the Brownville Limestone Member on the basis of what was then believed to be a regional disconformity rather than on paleontological criteria. Recent advances in fusulinid and conodont biostratigraphy provide tentative criteria upon which to suggest a change in the placement of the Virgilian-Permian boundary. A Russian delegation formally proposed at the International Congress on the Permian System of the World held in Perm, U.S.S.R. (Russia) in August 1991 that the base of the Permian System be established at the base of the Asselian Stage at the approximate stratigraphic position of the first inflated fusulinids (Sphaeroschwagerina vulgaris-S. fusiformis). Inflated schwagerinids (Paraschwagerina kansasensis) first occur, along with evolutionary changes in conodonts, in the Neva Limestone Member of the Grenola Limestone (Council Grove Group). Thus, if we assume that inflated schwagerinids arose globally at about the same time, the Neva Limestone Member is the oldest definitive Permian in the United States midcontinent, as related to the newly proposed boundary in Russia and Kazakhstan. Consequently, we propose that the Virgilian Stage in Kansas include rocks between the top of the Missourian Stage and the base of the Neva Limestone Member

Study of fluid transients in closed conduits interim report no. 65-2

Effects of two-phase fluids on flow characteristics in fluid conduit

Wide Field X-Ray Telescope Mission Concept Study Results

The Wide Field X-Ray Telescope (WFXT) is an astrophysics mission concept for detecting and studying extra-galactic x-ray sources, including active galactic nuclei and clusters of galaxies, in an effort to further understand cosmic evolution and structure. This Technical Memorandum details the results of a mission concept study completed by the Advanced Concepts Office at NASA Marshall Space Flight Center in 2012. The design team analyzed the mission and instrument requirements, and designed a spacecraft that enables the WFXT mission while using high heritage components. Design work included selecting components and sizing subsystems for power, avionics, guidance, navigation and control, propulsion, structures, command and data handling, communications, and thermal control

Advanced X-Ray Timing Array Mission: Conceptual Spacecraft Design Study

The Advanced X-Ray Timing Array (AXTAR) is a mission concept for submillisecond timing of bright galactic x-ray sources. The two science instruments are the Large Area Timing Array (LATA) (a collimated instrument with 2-50-keV coverage and over 3 square meters of effective area) and a Sky Monitor (SM), which acts as a trigger for pointed observations of x-ray transients. The spacecraft conceptual design team developed two spacecraft concepts that will enable the AXTAR mission: A minimal configuration to be launched on a Taurus II and a larger configuration to be launched on a Falcon 9 or similar vehicle