Improvements to a Response Surface Thermal Model for Orion

A study was performed to determine if a Design of Experiments (DOE)/Response Surface Methodology could be applied to on-orbit thermal analysis and produce a set of Response Surface Equations (RSE) that predict Orion vehicle temperatures within 10 F. The study used the Orion Outer Mold Line model. Five separate factors were identified for study: yaw, pitch, roll, beta angle, and the environmental parameters. Twenty-three external Orion components were selected and their minimum and maximum temperatures captured over a period of two orbits. Thus, there are 46 responses. A DOE case matrix of 145 runs was developed. The data from these cases were analyzed to produce a fifth order RSE for each of the temperature responses. For the 145 cases in the DOE matrix, the agreement between the engineering data and the RSE predictions was encouraging with 40 of the 46 RSEs predicting temperatures within the goal band. However, the verification cases showed most responses did not meet the 10 F goal. After reframing the focus of the study to better align the RSE development with the purposes of the model, a set of RSEs for both the minimum and maximum radiator temperatures was produced which predicted the engineering model output within +/-4 F. Therefore, with the correct application of the DOE/RSE methodology, RSEs can be developed that provide analysts a fast and easy way to screen large numbers of environments and assess proposed changes to the RSE factors

Local Aerodynamic Heat Transfer and Boundary-Layer Transition on Roughened Sphere-Ellipsoid Bodies at Mach Number 3.0

A wind-tunnel investigation was made to determine heat-transfer distributions on three steel sphere-ellipsoid bodies with surface roughnesses of 5, 100, and 200 microinches. Tests were conducted in the Langley 9- by 6-foot thermal structures tunnel at a Mach number of 3.0, free-stream Reynolds numbers (based on model spherical diameter) of 4.25 x 10(exp 6) and 2.76 x l0(exp 6), and at a stagnation temperature of 650 F. Pressure distributions were obtained also on a fourth model. The results indicated that the combination of surface roughness and boundary-layer cooling tended to promote early transition and nullify the advantages attributable to the blunt shape of the model for reducing local temperatures. Good correlation between experimental heating rates and those calculated from laminar theory was achieved up to the start of boundary-layer transition. The correlation also was good with the values predicted by turbulent theory for surface stations downstream from the 45 deg. station

Hepatocellular Neoplasm in a Wild-Caught Sheepshead Minnow (Cyprinodon variegatus) from the Northern Gulf of Mexico

The sheepshead minnow, Cyprinodon variegatus, is a widely distributed small fish species that inhabits estuaries and inshore waters from New England to northern South America. This species has been used extensively in aquatic environmental toxicity and carcinogenicity tests (Couch et al., 1981; Courtney and Couch, 1984). Hepatic neoplasms have been induced in the sheepshead minnow by exposure to several known chemical carcinogens including diethylnitrosamine (Couch and Courtney, 1987), methylazoxymethanolacetate (Hawkins etal., 1985), and dimethylbenz(a)anthracene (Hawkins et al., 1991). Because of its widespread distribution, limited home range, and proven sensitivity tocarcinogens, the sheepshead minnow appears to be a good candidate to serve as an in situ monitor of environmental carcinogens and other toxicants in coastal waters, especially those of the Gulf of Mexico and Caribbean Sea. To establish background information on the histopathological lesions in sheepshead minnows taken from the wild, we collected and examined specimens from an offshore site presumed to be free of chemical contamination. The present report concerns a hepatic neoplastic lesion, diagnosed as a hepatocellular adenoma, found in a wild sheepshead minnow. Neoplasms from wild sheepshead minnows or spontaneous neoplasms from laboratory specimens previously have not been reported

Hepatocellular Neoplasm in a Wild-Caught Sheepshead Minnow (Cyprinodon variegatus) from the Northern Gulf of Mexico

The sheepshead minnow, Cyprinodon variegatus, is a widely distributed small fish species that inhabits estuaries and inshore waters from New England to northern South America. This species has been used extensively in aquatic environmental toxicity and carcinogenicity tests (Couch et al., 1981; Courtney and Couch, 1984). Hepatic neoplasms have been induced in the sheepshead minnow by exposure to several known chemical carcinogens including diethylnitrosamine (Couch and Courtney, 1987), methylazoxymethanolacetate (Hawkins etal., 1985), and dimethylbenz(a)anthracene (Hawkins et al., 1991). Because of its widespread distribution, limited home range, and proven sensitivity tocarcinogens, the sheepshead minnow appears to be a good candidate to serve as an in situ monitor of environmental carcinogens and other toxicants in coastal waters, especially those of the Gulf of Mexico and Caribbean Sea. To establish background information on the histopathological lesions in sheepshead minnows taken from the wild, we collected and examined specimens from an offshore site presumed to be free of chemical contamination. The present report concerns a hepatic neoplastic lesion, diagnosed as a hepatocellular adenoma, found in a wild sheepshead minnow. Neoplasms from wild sheepshead minnows or spontaneous neoplasms from laboratory specimens previously have not been reported

Pollutant and Shell Thickness Determinations of Peregrine Eggs from West Greenland

A preliminary survey of breeding peregrine falcons (Falco peregrinus) in West Greenland in 1972 indicated both a high nesting density (one pair per 100 square miles) and a high production rate (2.25 young per pair or 2.57 per pair with young). ... Peregrines in the eastern United States and southern Canada experienced an increasing incidence of reproductive failures throughout the 1950s and early 1960s, culminating in the disappearance of the breeding populations by 1964. Studies were therefore carried out in the Northwest Territories and Alaska in 1966 to determine the status of the northern birds. No apparent abnormalities were found, and the reproduction was considered to be normal. ... Thin eggshells have been a characteristic of all the declining populations. The degree of thinning is closely associated with levels of the DDT compound p,p'-DDE in the eggs .... We have therefore examined the eggshells and shell fragments obtained in Greenland in 1972 for evidence of shell thinning and have measured the chlorinated hydrocarbons in two unhatched eggs. During the 1972 Greenland peregrine survey, 1 unhatched egg was collected from each of 2 eyries. In addition, shell fragments of 7 hatched eggs from 4 different females were collected. The mean thickness of these 9 eggs from 6 females was 0.298 mm ±0.018 (95 per cent C.L.: range 0.26-0.33), 14 per cent lower than the mean thickness of 42 peregrine eggs from Greenland that were collected before 1940 (thickness = 0.347 mm ±0.018 ...). Shell thinning of unhatched and broken eggs obtained from Ungava in 1967 and 1970 was somewhat more severe; the mean thickness was 21 per cent less than that of 59 peregrine egg-shells collected in the eastern Arctic between 1900 and 1940. ... DDE concentrations, expressed on either a wet weight or a lipid weight basis are within the range of those measured in peregrine eggs from Alaska and northern Canada. Polychlorinated biphenyls (PCB) have not previously been determined in peregrine eggs from the Arctic. Levels in the Greenland eggs were comparable to those of DDE .... The composition of the PCB mixture was similar to that of commercial mixtures containing 60 per cent chlorine by weight, Profiles of PCB residues in these eggs are strikingly like those of fat biopsies from peregrines in Chile, a further example of the global nature of the contamination to which this species is exposed. Body burdens of organochlorine compounds in the West Greenland peregrines are not therefore sufficiently high to affect reproductive success; the pollution ecology of this population might be considered comparable to that of other arctic-breeding peregrines in the mid-sixties. These also had comparatively high organochlorine levels with no apparent effect on reproduction, but many eggs approached a critical level of shell thinning. Because of the close relationships found in other populations between DDE concentrations and the degree of shell thinning and associated reproductive failures, we conclude that a comparatively small increase in the DDE levels to which these birds are exposed would endanger the population

A toy terrestrial carbon flow model

A generalized carbon flow model for the major terrestrial ecosystems of the world is reported. The model is a simplification of the Century model and the Forest-Biogeochemical model. Topics covered include plant production, decomposition and nutrient cycling, biomes, the utility of the carbon flow model for predicting carbon dynamics under global change, and possible applications to state-and-transition models and environmentally driven global vegetation models

A Chemical Composition Survey of the Iron-Complex Globular Cluster NGC 6273 (M 19)

Recent observations have shown that a growing number of the most massive Galactic globular clusters contain multiple populations of stars with different [Fe/H] and neutron-capture element abundances. NGC 6273 has only recently been recognized as a member of this "iron-complex" cluster class, and we provide here a chemical and kinematic analysis of > 300 red giant branch (RGB) and asymptotic giant branch (AGB) member stars using high resolution spectra obtained with the Magellan-M2FS and VLT-FLAMES instruments. Multiple lines of evidence indicate that NGC 6273 possesses an intrinsic metallicity spread that ranges from about [Fe/H] = -2 to -1 dex, and may include at least three populations with different [Fe/H] values. The three populations identified here contain separate first (Na/Al-poor) and second (Na/Al-rich) generation stars, but a Mg-Al anti-correlation may only be present in stars with [Fe/H] > -1.65. The strong correlation between [La/Eu] and [Fe/H] suggests that the s-process must have dominated the heavy element enrichment at higher metallicities. A small group of stars with low [alpha/Fe] is identified and may have been accreted from a former surrounding field star population. The cluster's large abundance variations are coupled with a complex, extended, and multimodal blue horizontal branch (HB). The HB morphology and chemical abundances suggest that NGC 6273 may have an origin that is similar to omega Cen and M 54.Comment: Accepted for Publication in The Astrophysical Journal; 50 pages; 18 figures; 8 tables; higher resolution figures are available upon request or in the published journal articl

Interview with Lydia Groves

An interview with Lydia Groves regarding her experiences in a one-room school house.https://scholars.fhsu.edu/ors/1063/thumbnail.jp

Cultural probes and the value of uncertainty

When reason is away, smiles will play. --- Paul Eluard and Benjamin Pére