768 research outputs found
Alien Registration- Watson, Harold P. (Wilton, Franklin County)
https://digitalmaine.com/alien_docs/19619/thumbnail.jp
The atmospheric effects of stratospheric aircraft: A topical review
In the late 1960s the aircraft industry became interested in developing a fleet of supersonic transports (SSTs). Between 1972 and 1975, the Climatic Impact Assessment Program (CIAP) studied the possible environmental impact of SSTs. For environmental and economic reasons, the fleet of SSTs was not developed. The Upper Atmosphere Research Program (UARP) has recently undertaken the responsibility of directing scientific research needed to assess the atmospheric impact of supersonic transports. The UARP and the High-Speed Research Program asked Harold Johnston to review the current understanding of aircraft emissions and their effect on the stratosphere. Johnston and his colleagues have recently re-examined the SST problem using current models for stratospheric ozone chemistry. A unique view is given here of the current scientific issues and the lessons learned since the beginning of CIAP, and it links the current research program with the assessment process that began two years ago
The versatility of a truss mounted mobile transporter for in-space construction
The Mobile Transporter (MT) evolution from early erectable structures assembly activities is detailed. The MT operational features which are required to support astronauts performing on-orbit structure construction or spacecraft assembly functions are presented and discussed. Use of the MT to perform a variety of assembly functions is presented. Estimated EVA assembly times for a precision segmented reflector approximately 20 m in diameter are presented. The EVA/MT technique under study for construction of the reflector (and the entire spacecraft) is illustrated. Finally, the current status of development activities and test results involving the MT and Space Station structural assembly are presented
The ecology and pathology of Trichostrongylus tenuis (nematoda), a parasite of red grouse( Lagopus Lagopus scoticus)
Trichostrongylus tenuis is a nematode that lives in the
caeca of wild red grouse. It causes disease in red grouse
and can cause fluctuations in grouse pop ulations. The aim
of the work described in this thesis was to study aspects
of the ecology of the infective-stage larvae of T.tenuis,
and also certain aspects of the pathology and immunology of
red grouse and chickens infected with this nematode.
The survival of the infective-stage larvae of T.tenuis
was found to decrease as temperature increased, at
temperatures between 0-30 C? and larvae were susceptible to
freezing and desiccation. The lipid reserves of the
infective-stage larvae declined as temperature increased
and this decline was correlated to a decline in infectivity
in the domestic chicken. The occurrence of infective-stage
larvae on heather tips at caecal dropping sites was
monitored on a moor; most larvae were found during the
summer months but very few larvae were recovered in the
winter. The number of larvae recovered from the heather
showed a good correlation with the actual worm burdens
recorded in young grouse when related to food intake.
Examination of the heather leaflets by scanning electron
microscopy showed that each leaflet consists of a leaf roll
and the infective-stage larvae of T.tenuis migrate into the
humid microenvironment' provided by these leaf rolls.
Scanning electron microscopy showed that the adult
nematodes burrowed into the mucosa as well as lying on its
surface and that the caecal mucosa of heavily infected
grouse became disrupted in areas of nematode activity. The
caecal mucosa of lightly infected grouse exhibited little
damage and the caecal mucosa of grouse treated with an
anthelmintic and shot 5-6 months later was similar to that
of lightly infected birds. Some of the nematodes from
these treated birds were covered in rosette-shaped cells
which have been tentatively identified as adherent
lymphocytes. The cuticle of adult T.tenuis was
superficially annulated but did not possess cuticular
ridges, as described in some other trichostrongyle
nematodes.
Primary and challenge infections with T.tenuis were
established in the domestic chicken and these reached
patency but nematodes were expelled in blood-stained balls
of mucus and all adult nematodes had been expelled from the
birds 30 days after dosing with infective-stage. Following
trickle doses of larvae,,there was a rise and then a fall in
nematode egg output but larvae administered later in the
trickle infection appeared to fail to establish. Light and
scanning electron microscopy showed haemorrhagic lesions
and blood spots on the caecal mucosa of infected chickens
and nematodes were found to burrow beneath mucus secreted
on the mucosal surface. There were significant increases
in the proportions of circulating leucocytes in infected
chickens, but only on certain days of infection. No
antibodies to T.tenuis were detected in the blood of
infected chickens. There was a decrease in the length of
the caeca of infected chickens during the period when the
Ill
nematodes were being expelled from the caeca. Nematode egg
output continued to rise during an infection in young red
grouse and there was no expulsion of nematodes from these
infected birds.
Infective-stage larvae that had been attenuated by cobalt
60 irradiation stimulated some degree of resistance to
challenge infection in the domestic chicken but not in the
red grouse. It was concluded that immunization with
irradiated larvae would be of little use in the control of
T.tenuis in red grouse
THE FLOWING AFTERGLOW AS A CHEMICAL REACTIONMASS SPECTROMETER: ACCURACY DETERMINATIONS AND REAGENT IONDEVELOPMENT
Henry's Law was utilized to determine the accuracy of the flowing afterglow at the University of Pittsburgh as a Chemical Reaction Mass Spectrometer (CR-MS). H3O+ and its first three hydrates were utilized as reagent ions in the CR-MS technique to quantify headspace concentrations over multiple series of dilute aqueous acetone, acetonitrile, and benzaldehyde/THF solutions. The temperature corrected Henry's Law constants, kHθ, of acetone, acetonitrile, benzaldehyde, and THF were calculated as 32.1+3.3, 45.2+6.5, 41.6+2.1, and 14.8+1.0 M atm-1, respectively. These values for acetone, acetonitrile, benzaldehyde, and THF are in agreement within error of the literature values of 28+3, 51+3, 39+3, and 14 M atm-1, respectively. These measurements suggest that our flowing afterglow can be utilized to accurately quantify multiple VOCs simultaneously via the CR-MS technique. H3O+ is the most commonly utilized reagent ion for the CR-MS technique due to its many advantages. This ion possesses two main limitations; it readily clusters with water and cannot decipher between isobaric (of the same mass) molecules. Due to its size and tendency to react like a proton, the trimethylsilyl group (TMS+) can be substituted for a proton to reduce clustering. Substitution of the nitrosyl cation for a proton creates a NO+ donor and an ion that can decipher between isobaric molecules. The preparation of R((CH3)3Si)ONO+, where R is a proton, trimethylsilyl, alkyl, or NO+ moiety, was attempted in order to make a reagent ion that can decipher between isobaric molecules, does not cluster, and, yet, maintains the advantages of H3O+ as a reagent ion. There were four different preparations attempted for ions of this type: NO+ + methoxytrimethylsilane, NO+ + hexamethyldisiloxane, ((CH3)3Si)2OH+ + methyl nitrite, and ((CH3)3Si)OH2+ + methyl nitrite. The clean production of R((CH3)3Si)ONO+ remains elusive. The reactions of NO+ and methoxytrimethylsilane and NO+ and hexamethyldisiloxane resulted in hydride and/or methide abstraction. No reaction occurred between protonated hexamethyldisiloxane and methyl nitrite. The reaction of protonated trimethysilanol with methyl nitrite did not produce an ion of the type R((CH3)3Si)ONO+ cleanly as it resulted in H(TMS)ONO+ (m/z 120) and (CH3)(TMS)ONO+ (m/z 134)
Anomalous CO2 Ice Toward HOPS-68: A Tracer of Protostellar Feedback
We report the detection of a unique CO2 ice band toward the deeply embedded,
low-mass protostar HOPS-68. Our spectrum, obtained with the Infrared
Spectrograph onboard the Spitzer Space Telescope, reveals a 15.2 micron CO2 ice
bending mode profile that cannot modeled with the same ice structure typically
found toward other protostars. We develop a modified CO2 ice profile
decomposition, including the addition of new high-quality laboratory spectra of
pure, crystalline CO2 ice. Using this model, we find that 87-92% of the CO2 is
sequestered as spherical, CO2-rich mantles, while typical interstellar ices
show evidence of irregularly-shaped, hydrogen-rich mantles. We propose that (1)
the nearly complete absence of unprocessed ices along the line-of-sight is due
to the flattened envelope structure of HOPS-68, which lacks cold absorbing
material in its outer envelope, and possesses an extreme concentration of
material within its inner (10 AU) envelope region and (2) an energetic event
led to the evaporation of inner envelope ices, followed by cooling and
re-condensation, explaining the sequestration of spherical, CO2 ice mantles in
a hydrogen-poor mixture. The mechanism responsible for the sublimation could be
either a transient accretion event or shocks in the interaction region between
the protostellar outflow and envelope. The proposed scenario is consistent with
the rarity of the observed CO2 ice profile, the formation of nearly pure CO2
ice, and the production of spherical ice mantles. HOPS-68 may therefore provide
a unique window into the protostellar feedback process, as outflows and heating
shape the physical and chemical structure of protostellar envelopes and
molecular clouds.Comment: Accepted to the Astrophysical Journal, 2013 February 15: 14 pages, 9
figures, 3 table
Tests of an alternate mobile transporter and extravehicular activity assembly procedure for the Space Station Freedom truss
Results are presented from a ground test program of an alternate mobile transporter (MT) concept and extravehicular activity (EVA) assembly procedure for the Space Station Freedom (SSF) truss keel. A three-bay orthogonal tetrahedral truss beam consisting of 44 2-in-diameter struts and 16 nodes was assembled repeatedly in neutral buoyancy by pairs of pressure-suited test subjects working from astronaut positioning devices (APD's) on the MT. The truss bays were cubic with edges 15 ft long. All the truss joint hardware was found to be EVA compatible. The average unit assembly time for a single pair of experienced test subjects was 27.6 sec/strut, which is about half the time derived from other SSF truss assembly tests. A concept for integration of utility trays during truss assembly is introduced and demonstrated in the assembly tests. The concept, which requires minimal EVA handling of the trays, is shown to have little impact on overall assembly time. The results of these tests indicate that by using an MT equipped with APD's, rapid EVA assembly of a space station-size truss structure can be expected
- …