Thermal Analysis for Orbiter and ISS Plume Impingement on International Space Station

The NASA Reaction Control System (RCS) Plume Model (RPM) is an exhaust plume flow field and impingement heating code that has been updated and applied to components of the International Space Station (ISS). The objective of this study was to use this code to determine if plume environments from either Orbiter PRCS jets or ISS reboost and Attitude Control System (ACS) jets cause thermal issues on ISS component surfaces. This impingement analysis becomes increasingly important as the ISS is being assembled with its first permanent crew scheduled to arrive by the end of fall 2000. By early summer 2001 , the ISS will have a number of major components installed such as the Unity (Node 1), Destiny (Lab Module), Zarya (Functional Cargo Block), and Zvezda (Service Module) along with the P6 solar arrays and radiators and the Z-1 truss. Plume heating to these components has been analyzed with the RPM code as well as additional components for missions beyond Flight 6A such as the Propulsion Module (PM), Mobile Servicing System, Space Station Remote Manipulator System, Node 2, and the Cupola. For the past several years NASA/JSC has been developing the methodology to predict plume heating on ISS components. The RPM code is a modified source flow code with capabilities for scarfed nozzles and intersecting plumes that was developed for the 44 Orbiter RCS jets. This code has been validated by comparison with Shuttle Plume Impingement Flight Experiment (SPIFEX) heat flux and pressure data and with CFD and Method of Characteristics solutions. Previous analyses of plume heating predictions to the ISS using RPM have been reported, but did not consider thermal analysis for the components nor jet-firing histories as the Orbiter approaches the ISS docking ports. The RPM code has since been modified to analyze surface temperatures with a lumped mass approach and also uses jet-firing histories to produce pulsed heating rates. In addition, RPM was modified to include plume heating from ISS jets to ISS components where the jet coordinates are specified, together with the engine cant angle. These latter studies have been focused on the PM with plumes from its reboost and ACS jets impinging on various ISS components and also focused on the Japanese H2 Transfer Vehicle (HTV) with the plumes from its reboost engines impinging on the Cupola window. This paper will present plume heating and surface temperature results on a number of ISS components with and without jet-firing histories, evaluate post-flight data, and describe any potential thermal issue

UPPER CRETACEOUS PEAY BENTONITES (NORTH-CENTRAL WYOMING): PROVENANCE AND TECTONICS INTERPRETATION FROM ASH COMPOSITION

The Peay bentonites belong to the basal Frontier Formation (Bighorn Basin, north-central Wyoming), primarily outcrop in the Bighorn Basin, rest on an extensively bioturbated sandstone unit, the Peay Sandstone, and are generally the thinner bentonitic unit. Beds of very light gray to greenish gray bentonite are also abundant in the lower Frontier units between Kaycee and Mayoworth (Powder River Basin) and are very rarely as much as 3 m thick. Bentonite occurs within the interstratified shale, sandstone, and siltstone sequences of the lower Frontier unit throughout much of the southwestern Powder River Basin. The purpose of this study is to use field, geochemical, petrological, and zircon morphology data to establish a chemical fingerprint of the original ash composition and to provide a tectonic and provenance interpretation. Peay units show distinct mineralogy consisting of quartz, kaolinite, illite, smectite, mixed-layer clays, K-feldspar, plagioclase, chlorite, calcite, and dolomite. Fairly uniform concentrations of SiO2, Na2O, CaO, MgO, Al2O3, Zr, Ti, Nb, and Ni have been noted in the Peay bentonites, such consistent concentrations of these elements in Peay bentonite samples imply that they have not been strongly modified by secondary processes. Peay bentonite samples show a consistent geochemical trend towards the alkali basalt field. On the basis of the similarity in gross stratigraphic development, feldspar compositions and trace element geochemistry, the source for the Peay bentonites is most likely located in the same general area. This is further supported by the presence of Ti-rich augite and the distinctive zircon morphology. The uniformity of composition and similarity in stratigraphic development of Peay bentonites over the region studied argues strongly against the contemporaneous involvement of several extrabasinal volcanoes. Evidence for active Cretaceous volcanism in the Idaho and in south-central Montana has been documented by Gill and Cobban, 1973. The Peay bentonites broadly correlate to the emplacement of batholiths in this region. Igneous rocks in northern Idaho and north-central Montana have yielded isotopic dates similar to those of the Peay bentonites (ca 90 Ma; Obradovich, 1993; Obradovich and Cobban 1975)

Lessons From SEED: A National Demonstration of Child Development Accounts

Lessons From SEED: A National Demonstration of Child Development Account

Extraction of visual motion information for the control of eye and head movement during head-free pursuit

We investigated how effectively briefly presented visual motion could be assimilated and used to track future target motion with head and eyes during target disappearance. Without vision, continuation of eye and head movement is controlled by internal (extra-retinal) mechanisms, but head movement stimulates compensatory vestibulo-ocular reflex (VOR) responses that must be countermanded for gaze to remain in the direction of target motion. We used target exposures of 50–200 ms at the start of randomised step-ramp stimuli, followed by >400 ms of target disappearance, to investigate the ability to sample target velocity and subsequently generate internally controlled responses. Subjects could appropriately grade gaze velocity to different target velocities without visual feedback, but responses were fully developed only when exposure was >100 ms. Gaze velocities were sustained or even increased during target disappearance, especially when there was expectation of target reappearance, but they were always less than for controls, where the target was continuously visible. Gaze velocity remained in the direction of target motion throughout target extinction, implying that compensatory (VOR) responses were suppressed by internal drive mechanisms. Regression analysis revealed that the underlying compensatory response remained active, but with gain slightly less than unity (0.85), resulting in head-free gaze responses that were very similar to, but slightly greater than, head-fixed. The sampled velocity information was also used to grade head velocity, but in contrast to gaze, head velocity was similar whether the target was briefly or continuously presented, suggesting that head motion was controlled by internal mechanisms alone, without direct influence of visual feedback

Plasmacytoma of bone, extramedullary plasmacytoma, and multiple myeloma: incidence and survival in the United States, 1992-2004

Population-based plasmacytoma incidence and survival data are sparse. We analyzed incidence rates (IRs), IR ratios (IRRs), and 5-year relative survival for plasmacytoma overall and by site - bone (P-bone) and extramedullary (P-extramedullary) - in the Surveillance, Epidemiology and End Results(SEER) Program (1992-2004). For comparison, we included cases of multiple myeloma (MM) diagnosed over the same time period in SEER. Incidence of MM (n = 23 544; IR 5.35/100 000 person-years) was 16-times higher than plasmacytoma overall (n = 1543; IR = 0.34), and incidence of P-bone was 40% higher than P-extramedullary (P < 0.0001). The male-to-female IRRs for P-bone, P-extramedullary, and MM were 2.0, 2.6, and 1.5, respectively. For plasmacytoma and MM, IRs were highest in Blacks, intermediate in Whites, and lowest in Asian/Pacific Islanders. Compared with Whites, the Black IR was approximate to 30% higher for P-extramedullary and P-bone and 120% higher for MM. IRs for all neoplasms increased exponentially with advancing age, less prominently at older ages for plasmacytoma than MM. Distinct age, gender, and race incidence patterns of plasma cell disorders suggest underlying differences in clinical detection, susceptibility, disease biology and/or aetiological heterogeneity. Five-year relative survival for P-bone, P-extramedullary, and MM varied significantly by age (<60/60+ years), supporting age-related differences in disease burden at presentation, disease biology, and/or treatment approaches