With missions to Jupiter, the spacecraft will be exposed for extended durations to solar wind radiation and the Jovian trapped radiation belt. This study is designed to determine the effect of these ...radiation environments on spacecraft bacterial isolates. The information can be used in the probability of contamination analysis for these missions. A bacterial subpopulation from Mariner Mars 1971 spacecraft (nine spore-forming and three non-spore-forming isolates) plus two comparative organisms, Staphylococcus epidermidis ATCC 17917 and a strain of Bacillus subtilis var. niger, were exposed to 2, 12, and 25 MeV electrons at different doses with simultaneous exposure to a vacuum of 1.3 x 10(-4) N m-2 at 20 and -20 degrees C. The radioresistance of the subpopulation was dependent on the isolate, dose and energy of electrons. Temperature affected the radioresistance of only the spore-forming isolates. Survival data indicated that spores were reduced approximately 1 log/1500 J kg-1 (10 J kg-1=1 krad), while non-spore-forming isolates (micrococci) were reduced 1.5-2 logs/1500 J kg-1 with the exception of an apparent radioresistant isolate whose resistance approached that of the spores. The subpopulation was found to be less resistant to lower energy than to higher energy electrons. The bacterial isolates were exposed to 3 keV protons under the same conditions as the electrons with a total fluence of 1.5 x 10(13) p cm-2 and a dose rate of 8.6 x 10(9) p cm-2 s-1. The results showed that only 20% of S. epidermidis and 45% of B. subtilis populations survived exposure to the 3 keV protons, while the mean survival of the spacecraft subpopulation was 45% with a range from 31.8% (non-spore-former) to 64.8% (non-spore-former). No significant difference existed between spore-forming and non-spore-forming isolates.
Bacillus subtilis
var.
niger
spores were placed on the surfaces of test coupons manufactured from typical spacecraft materials (stainless steel, magnesium, titanium, and aluminum). These coupons were ...then juxtaposed at the inoculated surfaces and subjected to test pressures of 0, 1,000, 5,000, and 10,000 psi. Tests were conducted in ambient, nitrogen, and helium atmospheres. While under the test pressure condition, the spores were exposed to 125 C for intervals of 5, 10, 20, 50, or 80 min, with survivor data being subjected to a linear regression analysis that calculated decimal reduction times. Differences in the dry-heat resistance of the test organism resulting from pressure, atmosphere, and material were observed.
Reviews Clark, Cecily; Seymour, M. C.; Gerritsen, Johan ...
English Studies,
19/2/1/, Letnik:
55, Številka:
1
Book Review
Recenzirano
Life in Anglo-Saxon England. By R. I. Page. (English Life Series, edited by Peter Quennell.) London: B. T. Batsford Ltd. 1970. xii + 179 pp. Price £ 1.50.
Middle English Poetry. An Anthology. Edited ...by Lewis J. Owen and Nancy Owen. (The Library of Literature.) New York: Bobbs-Merrill. 1971. xxii + 432 pp. Price $ 4.95 (paperback).
Medieval English Lyrics. Edited by T. Silverstein. (York Medieval Texts.) London: Edward Arnold. 1971. 184 pp. Price £ 1.75, paper £0.85.
The History of Reynard the Fox. Translated from the Dutch original by William Caxton. Edited by N. F. Blake. (Early English Text Society, 263.) London, New York, Toronto: Oxford University Press. 1970. lxxii + 170 pp., facs. Price £ 2.50.
The Life of Fulke Greville, First Lord Brooke. By Ronald A. Rebholz. Clarendon Press: Oxford University Press. 1971. xxv + 384 pp. Price £ 5.50.
Modesty and Cunning. Shakespeare's Use of Literary Tradition. By Karl F. Thompson. Ann Arbor: The University of Michigan Press. 1971. 176 pp. Price $ 3.15.
The Multiple Plot in English Renaissance Drama. By Richard Levin. Chicago and London: University of Chicago Press. 1971. xiv + 277 pp. Price £ 4.30.
Lyrics from English Airs 1596-1622. Edited and with an Introduction by Edward Doughtie. Cambridge, Mass.: Harvard University Press. 1970. xvii + 657 pp. Price $ 12.50.
Transformations in the Renaissance English Lyric. By Jerome Mazzaro. Ithaca and London: Cornell University Press. 1970. x + 214 pp. Price $ 6.75, £ 3.25.
Die Vorstellung vom Goldenen Zeitalter der englischen Sprache im 16., 17. und 18. Jahrhundert. Von Jürg Rusch. (Schweizer Anglistische Arbeiten, 69. Band.) Bern: Francke Verlag. 1972. Price Sfr. 30.-.
J. B. Leishman : Milton's Minor Poems. Edited, with a preface, by Geoffrey Tillotson. Pittsburgh, Pa.: Pittsburgh University Press. 1969. 360 pp. Price $ 6.95.
John Wallis, Grammar of the English Language, with an introductory grammatico-physical Treatise of Speech (or on the formation of all speech sounds). A new edition with translation and commentary by J. A. Kemp. (The Classics of Linguistics; Gen. Editors: D. Abercrombie, R. H. Robins.) London: Longman Group Ltd. 1972. viii + 400 pp.; 1 plate. Price £ 5.50.
Les Romans de Smollet. Etude Critique. Par Paul Gabriel Boucé. (Publications de la Sorbonne, Littératures 1.) Paris: Didier. 1971.472 pp.
The Wellesley Index to Victorian Periodicals 1824-1900. Volume II. Edited by Walter E. Houghton. Toronto: University of Toronto Press; London: Routledge & Kegan Paul. 1972. xxii + 1221 pp. Price $ 125.00.
Masks of Love and Death: Yeats as Dramatist. By John Rees Moore. Ithaca and London: Cornell University Press. 1971. xiv + 361 pp. Price £ 4.65.
William Carlos Williams: The American Background. By Mike Weaver. Cambridge: University Press. 1971. xii + 228 pp. Price £ 3.80.
The Late Plays of Eugene O'Neill. By Rolf Scheibler. (The Cooper Monographs, 15.) Bern: Francke Verlag. 1970. 222 pp. Price Sfr. 28.-.
PDF
