Compatibility testing of spacecraft materials and spacestorable liquid propellants

Compatibility data for aluminum alloy 2219-T87 and titanium alloy Ti-6Al-4V were obtained while these alloys were exposed to both liquid and vapor fluorine and FLOX at -320 F + or -10 F. These data were obtained using a new low cost compatibility method which incorporates totally sealed containers and double dogbone test specimens and propellants in the simultaneous exposure to vapor and liquid phases. The compatibility investigation covered a storage period in excess of one year. Pitting was more severe in the 2219-T87 aluminum alloy than in the Ti-6Al-4V titanium alloy for both fluorine and FLOX exposure. The degree of chemical attack is more severe in the presence of FLOX than in fluorine and phase. The mechanical properties of the two alloys were not affected by storage in either of the two propellants

A plan for a material compatibility program for oxygen difluoride (OF sub 2) and diborane (B sub 2 H sub 2) liquid propellants

Evaluation of metallic and nonmetallic construction material performance and reliability after long storage in OF2 and B2H

Long term storage test of titanium material with liquid fluorine propellant

The compatibility of 6AL-4V Ti with propellant grade GF2 and LF2 at 77 K for up to 3 years was investigated. Titanium double coupons, annealed or heat treated, with 16 or 64 RMS finishes, were immersed in F2 in individual Pyrex capsules and stored under LN2 for 29 and 39 months. Pre and post immersion tests were performed on the propellant and coupons. Chemical analysis of the propellant did not reveal any significant changes due to titanium corrosion. Gravimetric, visual, microscopic, and metallurgical examination with pitting analysis did not reveal gross corrosion of the titanium although pitting appears to be greater after 39 months exposure. The increase in pit size and number raises the possibility of unpredictable crack propagation instability. Fracture toughness tests are necessary to define this possibility

Divine Nature and the Natural Divine: The Marine Folklore of Pliny the Elder

This is the final version. Available on open access from Routledge via the DOI in this recordThis article considers the depiction of the marine world and its mythical inhabitants in the Natural History of Pliny the Elder. Through an ecocritical reading of the text, whereby I consider Pliny’s tendency to conceptualise Nature as a divinity and his consequential displacement of the traditionally anthropomorphic Greco-Roman gods, we can better understand the underlying factors in Pliny’s selective inclusion of ideas. I argue that Pliny’s divinisation of Nature, attributable to the influence of ancient Stoicism, has impacted his conception of the relationship between humans and Nature, an ideal centred around a post-anthropocentric framework. This, in turn, exerts a ripple effect onto the folkloric elements of the text. Both the anthropic figures of the sea (Nereids and Tritons) along with more bestial creatures (sea monsters) become dispossessed of traditionally divine attributes and associations with Poseidon/Neptune, leading to their representation in the Natural History as more ‘naturalised’ types of sea creatures

Ancient Sea Monsters and a Medieval Hero: The Nicoras of Beowulf

This is the final version. Available on open access from Shima Publishing via the DOI in this recordThis article examines the nicor (pl. nicoras) of Beowulf, a type of aquatic monster that appears elsewhere in Old English literature only in the Letter of Alexander to Aristotle and the Blickling Homily XVI. These beasts that attack Beowulf during his swimming contest with Breca and that surround the mere of Grendel and his mother are unfamiliar to modern scholars in terms of their precise nature, being assumed in previous scholarship to be generic water monsters, or hippopotamus-like beasts. Other scholarly suggestions for their underlying influence have been crocodiles and whales. I argue, however, that the nicoras can better be understood as having been influenced by the ancient traditions of the kētos (pl. kētē), the sea monster par excellence of Greco-Roman mythology, which also occupied a prominent place in the Christian imagination. The nicoras in these three Old English texts can be understood, like the dragon of Beowulf, as fantastical creatures that were primarily the product of discernible ancient traditions, rather than generic beasts or purely monstrous versions of real-world animals

An annotated list of the caddisflies (Trichoptera) of Florida: Part I. The family Hydroptilidae, with descriptions of five new species

Five new species of Hydroptila (Trichoptera: Hydroptilidae), H. murtlei sp. n., H. criokera sp. n, H. auriscuspa sp. n., H. santarosa sp. n., and H. ebroensis sp. n., from Florida are described and illustrated. We provide an annotated list of the 76 species known to occur in the state, including 10 species that represent new state records, one of which is also a new country record. New illustrations are presented for those species which were difficult to identify or exhibited new range extensions into Florida, namely: Hydroptila acadia Ross, H. ajax Ross, H. icona Mosely, H. latosa Ross, H. lloganae Blickle, H. maculata (Banks), H. novicola Blickle and Morse, H. wakulla Denning, Oxyethira arizona Ross, O. lumipollex Kelley and Harris, and O. simulatrix Flint

Compatibility testing of spacecraft materials and space-storable liquid propellants

Compatibility measurements were made for aluminum 2219-T87 alloy and titanium 6Al-4V alloy in the presence of liquid fluorine and flox. Results of post test characterization after exposure durations of 61 and 70 weeks are presented. Results of the total test program are analyzed

Inshore spawning of cobia (Rachycentron canadum) in South Carolina

We documented inshore spawning of the recreationally important cobia (Rachycentron canadum) in Port Royal Sound (PRS) and St. Helena Sound (SHS), South Carolina, during the period from April to June in both 2007 and 2008. Histological analysis of ovaries confirmed the presence of actively spawning females inshore, and gonadosomatic index (GSI) values from females collected inshore (mean=7.8) were higher than the values from females caught offshore (mean=5.6); both of these mean values indicate that spawning occurred locally. Additionally, we conducted an ichthyoplankton survey in 2008 and found cobia eggs and larvae as far as 10 and 15 km inshore from the mouths of SHS and PRS, respectively. A study of egg development that we conducted in 2007 and 2008 using hatchery-reared cobia eggs provided descriptions of embryological development of cobia. Comparison of visual and quantitative characteristics of the field-collected eggs with those of the hatchery-reared eggs allowed positive identification of eggs collected in plankton samples. The ages of field-collected eggs and presence of females with hydrated oocytes in PRS and SHS observed in our ichthyoplankton survey and histological analysis indicated that wild cobia spawn in the afternoon and early evening. The inshore migration of cobia from April to June, the presence of actively spawning females, significantly higher GSI values, and the collection of eggs inside PRS and SHS all confirm that these estuaries provide spawning habitat for cobia. Because of the potential for heavy exploitation by recreational anglers as cobia move inshore to spawn in South Carolina, current management strategies may require review

Evaluation of the stock structure of cobia (Rachycentron canadum) in the southeastern United States by using dart-tag and genetics data

Available tag-recapture and population genetics data for cobia (Rachycentron canadum) in the south-eastern United States were evaluated to provide information on population structure and determine the geographic boundary between stocks in the Gulf of Mexico and the Atlantic Ocean. The movements of 1750 cobia were evaluated on the basis of assigned tagging and recapture zones. Genetic samples from an additional 2796 cobia collected during the presumed spawning season were genotyped at 10 microsatellite loci, and standard population genetic statistical analyses were applied to the resulting sample data set. Tag- recapture results indicate that cobia tagged south of Cape Canaveral, Florida, primarily move between that area and the Gulf of Mexico and that cobia tagged north of Georgia have little interaction with the area south of Cape Canaveral. Cobia tagged at Cape Canaveral distributed widely throughout the entire southeastern coast of the United States. Genetic analysis results agree, indicating separate stocks that occur from Texas through Hobe Sound on the east coast of Florida and from Savannah, Georgia, to the Chesapeake Bay in Virgina, with distinct genetic groupings within the Atlantic Ocean stock. The results indicate a transition area that occurs from Cape Canaveral through northern Georgia, and additional data from this region are necessary to further refine the stock boundary