Enhanced LANDSAT images of Antarctica and planetary exploration

Since early in the LANDSAT program, black-and-white paper prints of band 7 (near infrared) of the LANDSAT multispectral scanner have been used extensively to prepare semicontrolled maps of Antarctica. Image-processing techniques are now employed to enhance fine detail and to make controlled image-mosaic maps in color. LANDSAT multispectral images of Antarctica help to expand our knowledge of extraterrestrial bodies by showing bare-ice areas as bright blue patches; on such patches meteorites tend to be concentrated and are collected. Many subtle flow features in Antarctic ice streams resemble features at the mouths of Martian outflow channels, which suggests that the channels also contained ice. Furthermore, flow lines in Antarctic ice sheets that merge with ice shelves resemble Martian flow features associated with dissected terrain along the Martian northern highland margin, and support the concept that ice was involved in the transport of material from the southern highlands to the northern lowland plains. In Antarctica, as on Mars, the virtual absence of fluvial activity over millions of years has permitted the growth of glacial and eolian features to unusually large sizes

The use of remote sensing in solving Florida's geological and coastal engineering problems

LANDSAT imagery and NASA high altitude color infrared (CIR) photography were used to select suitable sites for sanitary landfill in Volusia County, Florida and to develop techniques for preventing sand deposits in the Clearwater inlet. Activities described include the acquisition of imagery, its analysis by the IMAGE 100 system, conventional photointerpretation, evaluation of existing data sources (vegetation, soil, and ground water maps), site investigations for ground truth, and preparation of displays for reports

Computational Fluid Dynamics Analysis of an Idealized Modern Wingsuit

The modern wingsuit has been the subject of few scientific studies to date, and the prevailing design process remains the dangerous “guess-and-check” method. This study employed the commercial flow solver ANSYS Fluent to solve the steady Reynolds Averaged Navier-Stokes equations with turbulence models. The computational fluid dynamics (CFD) results provided information on the flow about a wingsuit designed with an airfoil cross section and large planform. The CFD simulation was performed using the Spalart-Allmaras turbulence model for the 3D wingsuit case and the k‑kl‑ω Transition model for the 2D airfoil case. Although the lack of experimental data available on wingsuit flight makes true validation difficult, the results of the 3D case were analyzed and compared to the 2D case, which was validated against data from the airfoil/wing management software Profili 2.0. The chosen airfoil had a stall angle of 13° and the wingsuit reached a stall angle of 48°, which appears higher than the actual effective angle of attack due to induced drag. This preliminary data indicates that the wingsuit as designed shows promise and could likely perform well under typical wingsuit flying conditions

Laser Velocimeter Measurements in the Leakage Annulus of a Whirling Shrouded Centrifugal Pump

Previous experiments conducted in the Rotor Force Test Facility at the California Institute of Technology have thoroughly examined the effect of leakage flows on the rotordynamic forces on a centrifugal pump impeller undergoing a prescribed circular whirl. These leakage flows have been shown to contribute substantially to the total fluid induced forces acting on a pump. However, to date nothing is known of the flow field in the leakage annulus of shrouded centrifugal pumps. No attempt has been made to qualitatively or quantitatively examine the velocity field in the leakage annulus. Hence the test objective of this experiment is to acquire fluid velocity data for a geometry representative of the leakage annulus of a shrouded centrifugal pump while the rotor is whirling using laser velocimetry. Tests are performed over a range of whirl ratios and a flowrate typical of Space Shuttle Turbopump designs. In addition to a qualitive study of the flow field, the velocity data can be used to anchor flow models

Dietary selenium intake among Ethiopian children in areas known for selenium spatial variability

Introduction: There is spatial variability of selenium (Se) in soil and crops in Ethiopia. We assessed the Se content of food items, breast milk, and urine among infants in Ethiopia from two areas with contrasting Se concentrations in soils. Methods: Dietary Se intakes among children (6–23 months) were evaluated using a weighed food record on two non-consecutive days. Also, spot urine samples from children and breast milk samples from their mothers were collected to determine Se concentration. Selenium concentrations in the samples were analyzed using an inductively coupled plasma mass spectrometer (ICP-MS). Results: Injera (prepared from teff and mixtures of other cereals) with a legume-based stew were the most frequently consumed foods by the children in both areas, followed by pasta. Overall, the Se concentration (mean ± SD) of food items, breast milk (12.2 ± 3.9 μg/L vs. 3.39 ± 1.5 μg/L), and urine samples (22.5 ± 11.5 μg/L vs. 3.0 ± 1.9 μg/L) from East Amhara were significantly higher than the corresponding samples from West Amhara (p < 0.001). The total Se intakes by the study children from East Amhara and West Amhara were 30.2 [IQ 25%, 14.2; IQ 75%, 54.1] and 7.4 [IQR 25%, 4.2; IQ 75%, 10.6] μg day–1, respectively; 31.5% of children from East Amhara and 92% of children from West Amhara were at risk of inadequate Se intakes. Urinary Se excretion accounted for 53 and 39% of daily dietary Se intake in East Amhara and West Amhara, respectively. Dietary Se intake was positively correlated with urinary Se excretion in East Amhara (r = 0.56; p < 0.001) but not among samples from West Amhara (r = 0.16; p ≥ 0.05), suggesting greater physiological Se conservation in a state of deficiency. Conclusion: There is spatial variability of Se in foods, breast milk, and urine in Ethiopia, suggesting the need for implementation of targeted agronomic interventions that enhance Se concentrations in the edible portion of plant foods

Universal statistical properties of poker tournaments

We present a simple model of Texas hold'em poker tournaments which retains the two main aspects of the game: i. the minimal bet grows exponentially with time; ii. players have a finite probability to bet all their money. The distribution of the fortunes of players not yet eliminated is found to be independent of time during most of the tournament, and reproduces accurately data obtained from Internet tournaments and world championship events. This model also makes the connection between poker and the persistence problem widely studied in physics, as well as some recent physical models of biological evolution, and extreme value statistics.Comment: Final longer version including data from Internet and WPT tournament

The Star-Forming Dwarf Galaxy Populations of two z ~ 0.4 Clusters: MS1512.4+3647 and Abell 851

We present the results of a deep narrow-band [OII] 3727 \AA emission-line search for faint ($g <$ 27), star-forming galaxies in the field of the $z=0.37$ MS1512.4+3647 cluster. We find no evidence for an over-density of emission-line sources relative to the field at $z \sim$ 0.4 (Hogg et al. 1998), and therefore conclude that the MS1512.4+3647 sample is dominated by field [OII] emission-line galaxies which lie along the $\sim$ 180 Mpc line of sight immediately in front and behind the cluster. This is surprising, given that the previously surveyed $z=0.41$ cluster Abell 851 has 3-4 times the field emission-line galaxy density (Martin et al. 2000). We find that the MS1512.4+3647 sample is deficient in galaxies with intermediate colors (1.0 $< g-i <$ 2.0) and implied star-formation exponential decay timescales $\tau \sim$ 100 Myr - 1 Gyr that dominate the Abell 851 emission-line galaxy population. Instead, the majority of [OII] emission-line galaxies surrounding the MS1512.4+3647 cluster are blue ($g-i \leq 1.0$) and forming stars in bursts with $\tau <$ 100 Myr. In both samples, galaxies with the shortest star-formation timescales are preferentially among the faintest star-forming objects. Their i luminosities are consistent with young stellar populations \sim 10^8 - 10^9 \Msun, although an additional factor of ten in stellar mass could be hiding in underlying old stellar populations. We discuss the implications for the star-formation histories of dwarf galaxies in the field and rich clusters.Comment: 26 pages, including 5 tables and 13 figures; accepted for publication in the Astrophysical Journa