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  • Other Sources  (1,056)
  • ASTROPHYSICS  (578)
  • INSTRUMENTATION AND PHOTOGRAPHY  (258)
  • MECHANICAL ENGINEERING  (183)
  • Inorganic Chemistry
  • Kartoffeln
  • Rock mechanics
  • Umweltmedizin
  • ddc:554.3
  • 1980-1984  (1,035)
  • 1945-1949
  • 1935-1939  (7)
  • 1920-1924  (8)
  • 1915-1919  (6)
  • 1983  (1,035)
  • 1938  (5)
  • 1937  (2)
  • 1921  (8)
  • 1918  (2)
  • 1916  (1)
  • 1915  (3)
Collection
Language
Years
  • 1980-1984  (1,035)
  • 1945-1949
  • 1935-1939  (7)
  • 1920-1924  (8)
  • 1915-1919  (6)
Year
  • 1
    Publication Date: 2022-12-22
    Description: Die oberrotliegenden rhyolithischen Tuffe der Prims-Mulde werden als Ignimbrite interpretiert. Sie sind maximal 110 m mächtig, gliedern sich durch wenige air-fall-Tuffe in mehrere Einheiten und können auf beiden Flanken der Prims-Mulde bis zu ca. 13 km weit verfolgt werden. Abgeplattete Bimse, Phänokristalle und zahlreiche Xenolithe treten in einer rötlichen, gering verschweißten Matrix auf. Die nicht dem Rotliegenden entstammenden Xenolithe, ihre Verteilung und die Ausrichtung von Bimslängsachsen weisen auf ein Liefergebiet für die pyroklastischen Ströme im Hunsrück hin. Gleichartig ausgebildete pyroklastische Ströme treten im Rotliegenden des Wittlicher Troges auf. Beide Vorkommen werden auf den im Hunsrück gelegenen, in devonische Gesteine eingebetteten Veldenzer Rhyolithschlot bezogen, der eine initiale Ignimbrit- Phase aufwies und wahrscheinlich den Förderort für die Vorkommen in den beiden Rotliegendtrögen darstellt.
    Description: Abstract: Rhyolithic tuffs within the Prims syncline of the Permocarboniferous late Hercynian intermontane Saar-Nahe trough, SW Germany, are interpreted as pyroclastic flow deposits. They are highly altered, weakly welded, and separated by thin air-fall tuffs. Their regional extent, petrography and xenolith content is described. The Devonian provenance of the xenoliths, their distribution, and the Orientation of the flattened pumice fragments all point to the Hunsrück north of the Saar-Nahe trough as the area the pyroclastic flows came from. The pyroclastic flows and similar flows in the next trough to the northwest, the Wittlich trough, are related to the Veldenz rhyolite in the Hunsrück which contains an initial ignimbrite phase and is considered to represent the feeder for these pyroclastic flows.
    Description: 1. Einleitung 2. Geologische Situation 3. Die Ignimbritfolge 3.1. Verbreitung, Volumen, Paläogeographie 3.2. Ausbildung der Ignimbrite 3.3. Abfolge der Ignimbrite 3.4. Beschreibung der Profile 3.5. Petrographie und Chemie 3.5.1. Ignimbrit-Typ Eisen 3.5.2. Ignimbrit-Typ Lauxwald 4. Die Xenolithe der Ignimbritfolge 4.1. Grünliche, grobkörnige Sandsteine 4.2. Feinsandsteine, Silt- und Tonsteine 4.3. Quarzite 4.4. Phyllite . 4.5. Chloritschiefer 5. Gesteine aus dem Rotliegenden und Unterdevon 6. Die Herkunft der Ignimbrite Schriften
    Description: research
    Keywords: ddc:554.3 ; Saar-Nahe-Becken ; Rotliegend ; Ignimbrite
    Language: German
    Type: doc-type:article , publishedVersion
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  • 2
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    Hessisches Landesamt für Bodenforschung, Wiesbaden
    In:  SUB Göttingen | KART B 104:5718 | KART H 86:5718
    Publication Date: 2022-11-22
    Description: Geologische Karte 1: 25 000 mit Erläuterungen. Digitalisat des FID GEO (Fachinformationsdienst Geowissenschaften der festen Erde), erstellt durch das GDZ (Göttinger Digitalisierungszentrum), Karte aus dem Bestand der SUB Göttingen. GeoTIFF erstellt durch FID GEO, SUB Göttingen. Koordinaten Vorlage: E 008 40 - E 008 50 / N 050 18 - N 050 12
    Description: map
    Description: DFG, SUB Göttingen
    Keywords: ddc:912 ; ddc:554.3 ; Rodheim ; Geologische Karte
    Language: German
    Type: doc-type:carthographicMaterial
    Format: 64
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  • 3
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    Hessisches Landesamt für Bodenforschung, Wiesbaden
    In:  SUB Göttingen | KART B 104:5519 | KART H 86:5519
    Publication Date: 2022-11-22
    Description: Geologische Karte 1: 25 000 mit Erläuterungen. Digitalisat des FID GEO (Fachinformationsdienst Geowissenschaften der festen Erde), erstellt durch das GDZ (Göttinger Digitalisierungszentrum), Karte aus dem Bestand der SUB Göttingen.
    Description: map
    Description: DFG, SUB Göttingen
    Keywords: ddc:912 ; ddc:554.3 ; ddc:943.2 ; Geologische Karte ; Hungen
    Language: German
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  • 4
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    Hessische Geologische Landesanstalt, Darmstadt
    In:  SUB Göttingen | KART B 104:6118 | KART H 86:6118
    Publication Date: 2022-11-22
    Description: Geologische Karte 1: 25 000 mit Erläuterungen. Digitalisat des FID GEO (Fachinformationsdienst Geowissenschaften), erstellt durch das GDZ (Göttinger Digitalisierungszentrum), Karte aus dem Bestand der SUB Göttingen.
    Description: map
    Description: DFG, SUB Göttingen
    Keywords: ddc:912 ; ddc:554.3 ; Roßdorf ; Geologische Karte
    Language: German
    Type: doc-type:carthographicMaterial
    Format: 122
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  • 5
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    Kraatz, Berlin
    In:  SUB Göttingen | KART B 140:1860 | KART H 140:Degow
    Publication Date: 2024-02-21
    Description: Geologische Karte 1: 25 000 mit Erläuterungen. Digitalisat des FID GEO (Fachinformationsdienst Geowissenschaften), erstellt durch das GDZ (Göttinger Digitalisierungszentrum), Karte aus dem Bestand der SUB Göttingen. Koordinaten Vorlage: Nullmeridian Ferro E 033 20 - 033 30 / N 054 12 - 054 06.
    Description: map
    Description: DFG, SUB Göttingen
    Keywords: ddc:912 ; ddc:554.3 ; Geologische Karte
    Language: German
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    Format: 38
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  • 6
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    Kraatz, Berlin
    In:  SUB Göttingen | KART B 140:1760 | KART H 140:Lassehne
    Publication Date: 2024-02-21
    Description: Geologische Karte 1: 25 000 mit Erläuterungen. Digitalisat des FID GEO (Fachinformationsdienst Geowissenschaften), erstellt durch das GDZ (Göttinger Digitalisierungszentrum), Karte aus dem Bestand der SUB Göttingen. Koordinaten Vorlage: Nullmeridian Ferro E 033 20 - 033 30 / N 054 18 - 054 12.
    Description: map
    Description: DFG, SUB Göttingen
    Keywords: ddc:912 ; ddc:554.3 ; Geologische Karte
    Language: German
    Type: doc-type:carthographicMaterial
    Format: 38
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  • 7
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    Kraatz, Berlin
    In:  SUB Göttingen | KART B 140:1289 | KART H 140:Königsberg-Ost
    Publication Date: 2024-05-23
    Description: Geologische Karte 1: 25 000 mit Erläuterungen. Digitalisat des FID GEO (Fachinformationsdienst Geowissenschaften), erstellt durch das GDZ (Göttinger Digitalisierungszentrum), Karte aus dem Bestand der SUB Göttingen. Koordinaten Vorlage: Nullmeridian Ferro E 038 10 – 038 20 / N 054 42 - 054 48.
    Description: map
    Description: DFG, SUB Göttingen
    Keywords: ddc:912 ; ddc:554.3 ; Geologische Karte
    Language: German
    Type: doc-type:carthographicMaterial
    Format: 78
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  • 8
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    In:  J. Geophys. Res., London, Army Corps of Engineers, Woodward-Clyde Consultants, vol. 88, no. 4, pp. 1153-1172, pp. 1013, (ISBN: 0-12-018847-3)
    Publication Date: 1983
    Keywords: Tectonics ; Friction ; Rock mechanics ; Fault zone ; JGR
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  • 9
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    In:  J. Geophys. Res., Kobe, Dec. 6-11, 1993, The Local Organizing Committee for the CRCM '93, vol. 88, no. B12, pp. 10359-10370, pp. 1517, (ISSN: 1340-4202)
    Publication Date: 1983
    Keywords: Rock mechanics ; Friction ; Fracture ; Modelling ; ductile ; Rheology ; JGR
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  • 10
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    In:  J. Earthquake Prediction Research, Basel, Inst. f. Geophys., Ruhr-Univ. Bochum, vol. 2, no. 4, pp. 33-45, pp. 1517, (ISSN: 1340-4202)
    Publication Date: 1983
    Keywords: Fracture ; Rock mechanics ; Hydraulic fracturing ; Stress ; Stress measurements ; Earthquake precursor: prediction research
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  • 11
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    In:  J. Geophys. Res., Luxembourg, Conseil de l'Europe, vol. 88, no. 3, pp. 555-568, pp. 1006, (ISSN: 1340-4202)
    Publication Date: 1983
    Keywords: Rock mechanics ; Fracture ; Friction ; Stress ; cracks and fractures (.NE. fracturing) ; JGR
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  • 12
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    Enke
    In:  Stuttgart, 403 pp., Enke, vol. 4, no. Publ. No. 12, pp. 267, (ISBN 3-534-14102-4)
    Publication Date: 1983
    Keywords: Textbook of geophysics ; Rock mechanics ; Laboratory measurements ; Physical properties of rocks ; Schoen ; Schon
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  • 13
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    In:  Lincei Rend., Heidelberg, Elsevier, vol. 24, no. 5, pp. 404-408, pp. 2099, (ISBN: 0-12-018847-3)
    Publication Date: 1915
    Keywords: Dislocation ; Rock mechanics ; Elasticity
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  • 14
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    In:  Lincei Rend., Heidelberg, Elsevier, vol. 24, no. 5, pp. 575-576, pp. 2099, (ISBN: 0-12-018847-3)
    Publication Date: 1915
    Keywords: Dislocation ; Rock mechanics ; Elasticity
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  • 15
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    In:  Phil. Trans. Roy. Soc., London, Dt. Geophys. Ges. e. V., vol. A221, no. B11, pp. 163-198, pp. L06304, (ISBN: 0534351875, 2nd edition)
    Publication Date: 1921
    Keywords: Rock mechanics ; cracks and fractures (.NE. fracturing) ; Fracture ; Rheology
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  • 16
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    In:  Pageoph, Luxembourg, Conseil de l'Europe, vol. 121, no. 2, pp. 443-475, pp. 2131, (ISSN: 1340-4202)
    Publication Date: 1983
    Keywords: Rock mechanics ; Friction ; Fracture
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  • 17
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    In:  Geol. Soc. Am. Bull., Minsk, Polish Geothermal Association, vol. 94, no. 4, pp. 1281-1288, pp. TC5003, (ISSN: 1340-4202)
    Publication Date: 1983
    Keywords: Geol. aspects ; Rock mechanics ; Crustal deformation (cf. Earthquake precursor: deformation or strain) ; Modelling ; Review article ; GSA
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  • 18
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    Springer Verlag
    In:  Berlin, Springer Verlag, vol. 4, no. ALEX(01)-FR-77-01, AFTAC Contract F08606-76-C-0025, pp. 329, (ISBN: 0-444-50309-9)
    Publication Date: 1983
    Keywords: Rock mechanics ; Fracture ; Boundary Element Method ; Elasticity
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  • 19
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    In:  Landwirtschaftl. Jahrbuch 86:823-924.
    Publication Date: 1938
    Description: Erarbeitung einer ausbaufähigen Methode für das Erfassen des Witterungsablaufes; Vergleichen einer Zwölfjahresreihe von Erträgen mit dem Witterungsablauf; bearbeitet wurden Winterroggen, Winterweizen, Wintergerste, Hafer, Sommergerste, Sommerweizen, Kartoffeln KATASTER-BESCHREIBUNG: Zusammenhang Witterung und Ertrag bei Getreide und Kartoffeln KATASTER-DETAIL: Delta Wasserversorgung (Frühjahr) - und Delta Wasserversorgung (Mai, Juni, Juli) +, dann Ertrag (Getreide) +; Delta T (frühe Entwicklungsstadien) -, dann Ertrag (Winterroggen, Hafer) +; Delta T (April) -, dann Ertrag (Hafer) +; Delta Nied (April, Mai) -, dann Ertrag (Winterweizen) +; delta T (Mai) -, dann Ertrag (Winterroggen) +; Delta T +, dann Ertrag (Kartoffel) +; Delta Nied (Juli, August) +, dann Ertrag (Kartoffel) +;
    Keywords: Brandenburg ; 1924-37 ; Kartoffeln ; Ertrag ; Getreide ; Witterung
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  • 20
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    In:  Deut. Landwirtschaflt. Presse 42: 420-421
    Publication Date: 1915
    Description: Korrelation der Sommer- und Winterniederschläge (Oktober-März) mit den Erträgen von Sommer- und Winterweizen, Roggen, Hafer, Gerste, Zuckerrüben und Kartoffeln, Winterniederschläge sind entscheidend für die Erträge, aber ertragsrelevanter sind die Sommerniederschläge und hier nicht in der Häufigkei, sondern der Menge im Zusammenspiel mit Temperatur, Sonnenscheindauer etc. KATASTER-BESCHREIBUNG: Beziehung zwischen der Niederschlagshöhe und dem Ertrag verschiedener Kulturen, getrennt für Winter- und Sommerniederschläge als Grafiken KATASTER-DETAIL:
    Keywords: Schlesien und Sachsen-Anhalt ; 1888-1907 ; Zuckerrüben ; Kartoffeln ; Ertrag ; Getreide ; Korrelationsmethode ; Niederschlag ; Roggen ; Weizen
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  • 21
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    In:  Zeitschrift für Hygiene und Infektionskrankheiten 120, 36
    Publication Date: 1937
    Description: 10 000 Erkrankungen und vielen Todesfällen, verursacht durch P. vivax und P. falciparum KATASTER-BESCHREIBUNG: der Sommer war so heiß gewesen, dass eine Übertragung der Erreger der Malaria tropica möglich war KATASTER-DETAIL:
    Keywords: Norddeutschland ; 1826 ; Umweltmedizin ; Infektionskrankheiten
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  • 22
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    In:  Beihefte zum Archiv für Schiffs- und Tropenhygiene 25 () Beiheft 2
    Publication Date: 1921
    Description: Temperaturabhängigkeit von Malariaerregern in einheimischen Anophelesmücken KATASTER-BESCHREIBUNG: optimale Generation-Entwicklung bei einer permanenten Außentemperatur von 24-30°C, unter 15-16°C keine Entwicklung KATASTER-DETAIL:
    Keywords: Europa ; 1901-1903 ; Umweltmedizin ; Infektionskrankheiten
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  • 23
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    In:  Deutsche Landwirtschaftliche Presse 45:287-288.
    Publication Date: 1918
    Description: Einfluss des Niederschlages auf die Höhe der Ertrages bei Getreide und Kartoffeln auf leichtem Sandboden KATASTER-BESCHREIBUNG: KATASTER-DETAIL:
    Keywords: Brandenburg ; 1910-1917 ; Kartoffeln ; Ertrag ; Niederschlag ; Trockenheit
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  • 24
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    In:  Klima - Wetter - Mensch, Woltereck, H. (Hrsg.), Verlag von Quelle und Meyer, Lepzig, S.127-229
    Publication Date: 1938
    Description: Bioklimatik einzelner Klimaelemente, atmosphärischer Zustände und Vorgänge KATASTER-BESCHREIBUNG: KATASTER-DETAIL:
    Keywords: Umweltmedizin
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  • 25
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    In:  Die Kartoffel, S. 90
    Publication Date: 1921
    Description: Zusammenhang Niederschlag und Wachstum der Kartoffelknolle KATASTER-BESCHREIBUNG: KATASTER-DETAIL:
    Keywords: Kartoffeln ; Ertrag ; Niederschlag ; Trockenheit
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  • 26
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    In:  Verlag von Julius Springer, Berlin
    Publication Date: 1938
    Description: Meteorotrope Krankheiten, Saisonkrankheiten KATASTER-BESCHREIBUNG: KATASTER-DETAIL:
    Keywords: Umweltmedizin
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  • 27
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    In:  Die Kartoffel, Seite 136
    Publication Date: 1921
    Description: Zusammenhang zwischen der Witterung und der Reifezeit der Kartoffelknolle KATASTER-BESCHREIBUNG: KATASTER-DETAIL:
    Keywords: Kartoffeln ; Ertrag ; Witterung
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  • 28
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    In:  Schriften der oekonomischen Gesellschaft im Freistaat Sachsen 8; No.3; p.1-24
    Publication Date: 1921
    Description: Diskussion einiger wichtiger Pflanzenkrankheiten im Ackerbau, wie z.B. Brandkrankheiten verschiedener Kulturen und verschiedenen Kartoffelkrankheiten. Gestützt werden die Anmerkungen von regionalen Beispielen aus Deutschland. Teilweise wird Bezug zum Wetter hergestellt. KATASTER-BESCHREIBUNG: KATASTER-DETAIL:
    Keywords: Deutschland ; 1920-1921 ; Kartoffeln ; Getreide ; Pflanzenkrankheit ; Hackfrüchte
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  • 29
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    In:  Jour. industr. and engin. Chem. 10; p.725-726
    Publication Date: 1918
    Description: Laborversuche zur Untersuchung des Zusammenhangs zwischen Frosteinwirkung und Fäulebefall auf die Speisestärke der Kartoffel KATASTER-BESCHREIBUNG: KATASTER-DETAIL:
    Keywords: Labor ; 1916-18 ; Kartoffeln ; Pflanzenkrankheit
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  • 30
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    In:  Klima - Wetter - Mensch, Woltereck, H. (Hrsg.), Verlag von Quelle und Meyer, Lepzig, S.253-296
    Publication Date: 1938
    Description: Seuchenerreger und -überträger und der Einfluss von Temperatur, Feuchtigkeit und Jahresschwankungen KATASTER-BESCHREIBUNG: KATASTER-DETAIL:
    Keywords: Umweltmedizin
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  • 31
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    In:  J. Appl. Mech., Luxembourg, Conseil de l'Europe, vol. 50, no. 2, pp. 343-349, pp. 2131, (ISSN: 1340-4202)
    Publication Date: 1983
    Keywords: Rheology ; Inelastic ; Friction ; Rock mechanics ; ductile ; instability
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  • 32
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    Allen & Unwin
    In:  London, Allen & Unwin, vol. 231, no. 3, pp. 2-203, (ISBN 0-470-02298-1)
    Publication Date: 1983
    Keywords: Rock mechanics ; Fracture ; Boundary Element Method ; Elasticity ; Textbook of physics
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  • 33
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    Chapmann & Hall
    In:  London, Chapmann & Hall, vol. 558, no. XVI:, pp. 1-14, (ISBN 3-9808493-1-7)
    Publication Date: 1983
    Keywords: Textbook of geophysics ; Rock mechanics ; Fracture ; Elasticity ; Rheology
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  • 34
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    In:  J. Geophys. Res., Kunming, China, D. Reidel Publishing Company, vol. 88, no. 2, pp. 9331-9340, pp. L09303, (ISSN: 1340-4202)
    Publication Date: 1983
    Keywords: Rock mechanics ; Seismicity ; Fracture ; JGR
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  • 35
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    Universität Frankfurt/Main
    In:  Berichte des Instituts für Meteorologie und Geophysik, Universität Frankfurt/Main, Universität Frankfurt/Main, vol. 1034, no. 53, pp. 206, (ISBN 3-933346-037)
    Publication Date: 1983
    Keywords: Rock mechanics ; Tectonics ; Earth model, also for more shallow analyses ! ; Velocity analysis ; Electromagnetic methods/phenomena ; Elasticity ; Physical properties of rocks ; earth mantle
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  • 36
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    Univ. of London
    In:  Unpublished Ph.D. Thesis, London, Univ. of London, vol. C 560, 183 pp., no. GL-TR-89-0147, pp. 205-211, (ISBN 3-933346-037)
    Publication Date: 1983
    Keywords: Fracture ; Rock mechanics ; Laboratory measurements
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  • 37
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    Martinus Nijhoff Publ.
    In:  Bull., Open-File Rept., Hydraulic Fracturing and Geothermal Energy, Boston, Martinus Nijhoff Publ., vol. IV, no. 1, pp. 291-305, (ISBN 1-86239-165-3, vi + 330 pp.)
    Publication Date: 1983
    Keywords: Rock mechanics ; Fracture ; Stress ; Hydraulic fracturing ; Geothermics ; ERYBACKI
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  • 38
    Publication Date: 2004-12-04
    Description: An improved 4 to 18 micron array camera system was developed at NASA Goddard SFC for astronomical photometry, using an Aerojet Electro Systems Corp. 16 x 16 Si:Bi accumulation mode charge injection device (AMCID) which could be suitable for eventual low-background spaceflight applications. An astronomical observing program using this device was carried out as a collaboration between NASA Goddard (Infrared and Radio Astronomy Branch and Micro Electronics Branch), the Harvard/Smithsonian Center for Astrophysics, and Steward Observatory of the University of Arizona. In 1983 the camera system was revised, and a new Aeroject Si:Bi array with 16 x 16 active pixels was obtained from NASA/Ames Research Center as part of a new scientific collaboration between the Ames and Goddard infrared array research groups. The 16 x 16 device had sufficiently good sensitivity, uniformity and noise characteristics to be used for successful observations at the Mt. Lemmon 60 and 61 inch telescopes in May 1983. Complete laboratory characterization of the 16 x 16 array was carried out in summer of 1983. Initial results indicate that this detector has sensitivity and noise characteristics comparable to other devices from the same generation of Aerojet arrays.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: NASA. Ames Research Center, Infrared Detector Technology Workshop; 12 p
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  • 39
    Publication Date: 2011-08-18
    Description: New frequency calibration tables are required to keep abreast of the resolution attainable by currently available tunable lasers. One key to the generation of tables with requisite accuracy involves accurate heterodyne frequency measurements; another key consists of reliable fitting and analysis. Coordinated activity in NBS involves selection of suitable molecular calibration candidates, their frequency measurement and analysis, and dissemination of the results in the form of frequency calibration tables. Current status of these efforts is described.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
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  • 40
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    In:  Other Sources
    Publication Date: 2011-08-18
    Description: Einstein solid-state-spectrometer (SSS) spectra are presented for the Crab Nebula, Cas A, SN 1006, the Tycho SNR, and the Kepler SNR. The history of X-ray observations of SNRs is reviewed; the SSS instrument is briefly characterized; a reduction technique which accounts for all background sources in the 0.5-4.5-keV band is applied; and the physical models of SNRs constructed to reproduce the refined spectra are discussed. The limitations of the modeling methods and the need for further observations, especially of localized regions, are indicated.
    Keywords: ASTROPHYSICS
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  • 41
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    In:  Other Sources
    Publication Date: 2011-08-18
    Description: New data indicate that red giants are surrounded by geometrically thick chromospheres of several stellar radii extent. Such chromospheres occur among stars which apparently lack coronae. Maintenance of this extended warm region may require non-compressional wave heating of a magnetic character, and this may provide a crucial clue to the mechanism of rapid mass loss from red giant stars.
    Keywords: ASTROPHYSICS
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  • 42
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    Publication Date: 2011-08-18
    Description: A new extension to optogalvanic spectroscopy, in which electrons detached from negative ions formed in the discharge are observed as a function of incident laser wavelength, has been developed. The determination of the electron affinities of I(-) and Cl(-) atomic ions is described. The potential of the technique for studying the spectroscopy of molecular negative ions is also discussed.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Journal de Physique (ISSN 0449-1947); 44; C7-461 t
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  • 43
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    Publication Date: 2011-08-18
    Description: Two-phase turbines would be useful in Rankine cycles using low-quality or saturated-liquid working fluids. The chief problem is low efficiency due to slip losses in nozzles and due to liquid impact and friction losses in rotors. To raise efficiency, a staging method was tested in which the first stage operated at high speed with low relative liquid velocity, and the second stage recovered the first-stage exit energy. The theoretical efficiency for an experimental turbine operating with Refrigerant-22 was raised from 55 percent to 66 percent, and the measured efficiency was raised from 52 percent to 57 percent.
    Keywords: MECHANICAL ENGINEERING
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  • 44
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    Publication Date: 2011-08-18
    Description: An overview of the DOE/NASA Automotive Stirling Engine Project is presented. The background and objectives of the project are reviewed. Project activities are described and technical progress and status are presented and assessed. Prospects for achieving the objective 30 percent fuel economy improvement are considered good. The key remaining technology issues are primarily related to life, reliability and cost, such as piston rod seals, and low cost heat exchanges. Previously announced in STAR as N83-27924
    Keywords: MECHANICAL ENGINEERING
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  • 45
    Publication Date: 2011-08-18
    Description: A holographic interferometer system has been installed in the NASA Ames 2- by 2-Foot Transonic Wind Tunnel. The system incorporates a modern 10 pps, Nd:YAG pulsed laser which provides reliable operation and is easy to align. The spatial filtering requirements of the unstable resonator beam are described, as well as the integration of the system into the existing schlieren system. A two-plate holographic interferometer is used to reconstruct flow field data. For static wind tunnel models, the single exposure holograms are recorded in the usual manner; however, for dynamic models such as oscillating airfoils, synchronous laser hologram recording is used.
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  • 46
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    Publication Date: 2011-08-18
    Description: The Kitt Peak 2.1-m telescope and Intensified Image Dissector Scanner have been used to gather spectrophotometric data in the 3600-5200 A spectral region for five H II regions in the spiral galaxy NGC 628. The Pagel et al (1979) technique was then applied to determine the relative number abundances of O to H in each of the H II regions. An examination of the abundance values obtained as a function of the radial coordinate yields an O gradient of -0.05 + or - 0.03 dex/kpc.
    Keywords: ASTROPHYSICS
    Type: Astronomical Society of the Pacific, Publications (ISSN 0004-6280); 95; 986-988
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  • 47
    Publication Date: 2011-08-18
    Description: The existence of a possible influence of the large-scale structure of the universe on local physics is discussed. A particular realization of such an influence is discussed in terms of the behavior in time of atomic and gravitational clocks. Two natural categories of metric theories embodying a cosmic infuence exist. The first category has geodesic equations of motion in atomic units, while the second category has geodesic equations of motion in gravitational units. Equations of motion for test bodies are derived for both categories of theories in the appropriate parametrized post-Newtonian limit and are applied to the Solar System. Ranging data to the Viking lander on Mars are of sufficient precision to reveal (1) if such a cosmological influence exists at the level of Hubble's constant, and (2) which category of theories is appropriate for a descripton of the phenomenon.
    Keywords: ASTROPHYSICS
    Type: Physical Review D - Particles and Fields, 3rd Series (ISSN 0556-2821); 28; 1822-182
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  • 48
    Publication Date: 2011-08-18
    Description: NGC 7027 was observed with a multichannel grating spectrometer from 5.2 to 7.5 microns at a spectral resolving power of 120-200. Two new dust emission features are resolved at 5.62 and 6.95 microns, and for the first time the Ni II fine-structure line at 6.64 microns is detected. It is shown that a single molecular dust constituent might account for six of the nine observed dust features between 2 and 14 microns. The strength of the Ni II line indicates either that Ni is not depleted in the neutral gas, or that the line is formed at high density.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal, Part 1 (ISSN 0004-637X); 274; 666-670
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  • 49
    Publication Date: 2011-08-18
    Description: Visual absolute magnitudes of classical Cepheids, metal-poor RR Lyrae stars and short-period type II Cepheids have been determined with very high precision by combining a large number of old and new astrophysical data. Five independent methods (four observational and one theoretical) have been successfully used: (1) secular and statistical parallaxes; (2) moving-group parallaxes; (3) cluster main-sequence fitting; (4) the Baade-Wesselink method and its modifications; and (5) light-curve and velocity-curve fitting (the theoretical method). With these five adopted methods, the zero point of the galactic and extragalactic distance scale can be set on a relatively firm and self-consistent basis. Classical Cepheids and RR Lyrae stars now provide essentially identical distances to nearby galaxies: the distance modulus to the Large Magellanic Cloud is 18.5 and to the Small Magellanic Cloud is 18.8, both with an uncertainty of 0.1. The distance to the center of our Galaxy is 8.6 plus or minus 0.5 kiloparsecs. The major uncertainty in these values lies in the correction for interstellar extinction.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal, Part 1 (ISSN 0004-637X); 274; 20-30
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  • 50
    Publication Date: 2011-08-18
    Description: A new two-wavelength lidar technique for remotely measuring the pressure profile using the trough absorption region between two strong lines in the oxygen A band is described. The theory of integrated vertical path, differential ranging, and horizontal-path pressure measurements is given, with methods to desensitize and correct for temperature effects. The properties of absorption troughs are described and shown to reduce errors due to laser frequency jitter by up to two orders of magnitude. A general analysis, including laser bandwidth effects, demonstrates that pressure measurements with an integrated-vertical-path technique are typically fifty times more accurate than with a differential ranging technique. Simulations show 0.1-0.3 percent accuracy for ground and Shuttle-based pressure-profile and surface-pressure experiments.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Applied Optics (ISSN 0003-6935); 22; 3759-377
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  • 51
    Publication Date: 2011-08-18
    Description: It is pointed out that the line profile coefficients for spontaneous and stimulated emission are identical in low-intensity radiation fields. In more intense radiation fields, however, the stimulated emission profiles in the radiative transfer equation and in the rate equations for the atomic level populations may differ from each other, owing to their different physical nature. A seeming discrepancy between the stimulated emission profiles of the usual semi-classical aproach and a recent quantum mechanical approach by Cooper et al. (1982), which should also be valid for intense 'broadband' fields, is discussed and shown to have negligible consequences for low-intensity radiation fields.
    Keywords: ASTROPHYSICS
    Type: Astronomy and Astrophysics (ISSN 0004-6361); 127; 1, Oc; 224-226
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  • 52
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    Publication Date: 2011-08-18
    Description: Observational evidence for Baryon symmetric (matter/antimatter) cosmology and future observational tests are reviewed. The most significant consequences of Baryon symmetric cosmology lie in the prediction of an observable cosmic background of gamma radiation from the decay of Pi(O)-mesons produced in nucleon-antinucleon annihilations. Equations for the prediction of the gamma ray background spectrum for the case of high redshifts are presented. The theoretical and observational plots of the background spectrum are shown to be in good agreement. Measurements of cosmic ray antiprotons and the use of high energy neutrino astronomy to look for antimatter elsewhere in the universe are also addressed. Previously announced in STAR as N83-10996
    Keywords: ASTROPHYSICS
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  • 53
    Publication Date: 2011-08-18
    Description: In this paper, some of the effects of unbalance on the nonlinear response and stability of flexible rotor-bearing systems is presented from both a theoretical and experimental standpoint. In a linear system, operating above its stability threshold, the amplitude of motion grows exponentially with time and the orbits become unbounded. In an actual system, this is not necessarily the case. The actual amplitudes of motion may be bounded due to various nonlinear effects in the system. These nonlinear effects cause limit cycles of motion. Nonlinear effects are inherent in fluid film bearings and seals. Other contributors to nonlinear effects are shafts, couplings and foundations. In addition to affecting the threshold of stability, the nonlinear effects can cause jump phenomena to occur at not only the critical speeds, but also at stability onset or restabilization speeds.
    Keywords: MECHANICAL ENGINEERING
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  • 54
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    Publication Date: 2011-08-18
    Description: Attention is given to semidetached binaries of the Algol type and to related interacting systems, such as Beta Lyrae and the W Serpentis stars. A brief description is given of observational problems. The basic properties of the Algol variables are satisfactorily explained by means of evolutionary models that assume considerable mass transfer between the components. It is pointed out that ultraviolet spectra obtained with the IUE satellite corroborate the view that the present subgiant secondary component was initially the more massive star and that it has been stripped of a large fraction of its mass so that the deep layers affected by CNO processing are now denuded. It is believed that the present-day 'classical' Algols must have undergone a phase of rapid mass transfer in the past and that Beta Lyrae and the W Serpentis stars are probably closer to that stage than ordinary Algols. Around the accreting star a complex structure is formed, and an induced stellar wind may blow a large part of the transferred matter out of the system.
    Keywords: ASTROPHYSICS
    Type: Royal Astronomical Society of Canada, Journal (ISSN 0035-872X); 77; 283-304
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  • 55
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    Publication Date: 2011-08-18
    Description: The paper addresses the potential that ceramic materials can play an important role in future automotive powerplants - both advanced heat engines and advanced battery systems. A number of related experimental programs are reviewed including ceramics for gasoline and diesel piston engines, gas turbine and Stirling Engines and sodium-sulfur batteries. A strong integrated program to develop ceramics technology is recommended.
    Keywords: MECHANICAL ENGINEERING
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  • 56
    Publication Date: 2011-08-18
    Description: Airborne laser-induced, depth-resolved water Raman backscatter is useful in the detection and mapping of water optical transmission variations. This test, together with other field experiments, has identified the need for additional field experiments to resolve the degree of the contribution to the depth-resolved, Raman-backscattered signal waveform that is due to (1) sea surface height or elevation probability density; (2) off-nadir laser beam angle relative to the mean sea surface; and (3) the Gelbstoff fluorescence background, and the analytical techniques required to remove it. When converted to along-track profiles, the waveforms obtained reveal cells of a decreased Raman backscatter superimposed on an overall trend of monotonically decreasing water column optical transmission.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Applied Optics (ISSN 0003-6935); 22; 3778-378
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  • 57
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    Publication Date: 2011-08-18
    Description: The problem posed by the existence of a negative buoyancy work region at the top of cellular type convection in a deeply stratified superadiabatic layer (Massaguer and Zahn, 1980) is addressed. It is approached by studying two-dimensional cellular compressible convection with different physical parameters. The results suggest that a large viscosity, together with density stratification, is responsible for the buoyancy reversal. The numerical results obtained are analyzed. It is pointed out, however, that in an astrophysical situation a fluid involved in convection will generally have very small viscosity. It is therefore thought unlikely that buoyancy reversal occurs in this way.
    Keywords: ASTROPHYSICS
    Type: Astrophysics and Space Science (ISSN 0004-640X); 95; 2, Se; 453-457
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  • 58
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    Publication Date: 2011-08-18
    Description: Duley (1982) has proposed that many of the diffuse interstellar bands in the wavelength interval 542-677 nm arise from vibronic transitions of Cr (3+) ions in MgO grains. No explanation has been offered for the fact that as many as 85 of the possible 108 transitions of this system have not been observed in the interstellar medium. Moreover, the relative intensities of the diffuse bands which are observed appear to be inconsistent with their assignment. It is therefore concluded that this model is not consistent with the observations.
    Keywords: ASTROPHYSICS
    Type: Astrophysics and Space Science (ISSN 0004-640X); 95; 1, Se
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  • 59
    Publication Date: 2011-08-18
    Description: The plausibility of relatively pure diatomic oxide crystals forming in the expanding atmospheres of cool stars is commented on, and the likelihood of SiO grains condensing is discussed on the basis of laboratory nucleation experiments. Results of annealing experiments are used to consider the further evolution of silicon oxide and silicate grains. The evidence shows that SiO solids form only when SiO condenses directly onto surfaces, and that the probability of pure crystalline SiO grains forming is rather small.
    Keywords: ASTROPHYSICS
    Type: Astrophysics and Space Science (ISSN 0004-640X); 95; 1, Se
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  • 60
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    Publication Date: 2011-08-18
    Description: Newly defined characteristics of planetary nebulae (PN) derived from analysis of a photometric survey of 57 PN are reported. The data were combined with measurements of 27 other PN made since 1918 and were found to indicate core masses ranging from 0.55-1.0 solar mass. N/O elemental abundance ratios observed were correlated with the planetary nuclei masses, and were in direct proportion. IUE data on PN that overlapped a large part of the survey indicated that the PN in the galactic disk are more massive than PN in the halo. It is suggested that PN evolve into white dwarfs, a hypothesis supported by astrometric solutions for three nearby visual binaries featuring white dwarfs with well-determined masses. It is noted, however, that PN with masses exceeding one solar mass have been sighted in the Magellanic Clouds.
    Keywords: ASTROPHYSICS
    Type: Nature (ISSN 0028-0836); 305; 670
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  • 61
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    Publication Date: 2011-08-18
    Description: Two new possible planetary nebulae have been identified using the Parker, Gull, and Kirshner (1979) emission-line survey of the galactic plane. Both objects exhibit very strong forbidden O III lambda 5007 line emission, a symmetrical morphology, and a faint blue central star.
    Keywords: ASTROPHYSICS
    Type: Astronomical Society of the Pacific, Publications (ISSN 0004-6280); 95; 614-618
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  • 62
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    Publication Date: 2011-08-18
    Description: First IUE spectrograms of the peculiar emission-line object M1-2 (= VV 8) are presented. In the wavelength region 1150-3200 A this object is characterized by emission lines superposed on a moderately strong continuum. Some ultraviolet and optical properties of M1-2 are discussed in the context of symbiotic stars and protoplanetary and planetary nebulae. An E(B-V) extinction of 0.37 mag is obtained from the ratio of the He II flux at 1640 and 4686 A and is compared with values derived from other parameters. The ultraviolet observations suggest that M1-2 is a young, high-density planetary nebula of excitation class 5 or 6 with characteristics similar to IC 4997.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal, Part 1 (ISSN 0004-637X); 275; 628-635
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  • 63
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    Publication Date: 2011-08-18
    Description: Obsrvations and theoretical investigations of the Gum nebula (GN) since about 1971 are reviewed. Direct observations of the GN, the Vela X supernova remnant (SNR), the Vela pulsar, and other stars in or near the GN are discussed with those of related phenomena such as the radio loops and known SNRs; the emphasis is on studies of the interstellar absorption lines, the evidence for hot gas in the GN, and the extended diffuse emission. The four basic models proposed for the GN are considered: a fossil Stromgren sphere, an old SNR, an H II region, or a superbubble. The GN physical parameters predicted by each model are listed in a table and compared. A minimum explanation which attributes the 36 x 36-deg filamentary structure and the 125-pc radius structure to the action of the stellar winds from Zeta Pup and Gamma-2 Vel (and perhaps the effect of a Vel X supernova explosion 20,000 years ago) is found most appropriate, at least until the questions of the net expansion rate of the GN (about 20 km/sec or about zero?) and the existence of the diffuse emission beyond the filamentary structure are resolved by observations.
    Keywords: ASTROPHYSICS
    Type: Comments on Modern Physics, Part C - Comments on Astrophysics (ISSN 0146-2970); 10; 1-14
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  • 64
    Publication Date: 2011-08-18
    Description: Previous work on electron heating mechanisms operating at the supercritical earth's bow shock is extended to the generally lower Mach number interplanetary shocks. This is done by studying electron velocity distributions observed both upstream and downstream of interplanetary shocks observed by ISEE 3 between August 1978 and December 1979. It is found that perpendicular heating accompanied by little or no parallel heating occurs at the weaker shocks but that parallel heating is dominant for the stronger shocks. When perpendicular heating is dominant, downstream velocity distributions are for the most part Gaussian at low energies (core) and Lorentzian at high energies (halo). When parallel heating is dominant, however, these distributions are flat-topped at low energies, having power law extensions to higher energies. At the weaker shocks, the observations are consistent with electron heating resulting from conservation of the magnetic moment, whereas at the stronger shocks the heating is quite similar to that observed at the earth's bow shock.
    Keywords: ASTROPHYSICS
    Type: Journal of Geophysical Research (ISSN 0148-0227); 88; 9949-995
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  • 65
    Publication Date: 2011-08-18
    Description: Preliminary inspection of archival high-dispersion ultraviolet spectra obtained by the International Ultraviolet Explorer reveal sharp shortward-shifted features in the spectra of O subdwarfs. In three examples presented here, BD + 75.325 deg, HD 128220 B, and BD + 28.4211 deg, stable, multiple, discrete shortward-shifted components of the N V, C IV, and Si IV resonance doublets are seen. The available data suggest that some of these features are persistent, being relatively stable in velocity and intensity over at least 9 months. It is tentatively suggested that the mechanism, or mechanisms, producing these discrete features operates universally in hot stars, from luminous O and B stars down through the O subdwarfs to include the hot white dwarfs. If true, this has important ramifications for current knowledge of mass loss in hot stars.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal, Part 2 - Letters to the Editor (ISSN 0004-637X); 274; L87-L91
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  • 66
    Publication Date: 2011-08-18
    Description: Ultraviolet images of the SAB(s)c I-II galaxy M83 (NGC 5236) obtained with a rocketborne telescope in broad bandpasses centered at 1540 A and 2360 A show a bright resolved nuclear source which accounts for approximately 20 percent of the flux of the galaxy in both bandpasses. Low-resolution International Ultraviolet Explorer spectra of this source reveal an energy distribution similar to that of the starburst nucleus of NGC 7714. Strong blueshifted absorption lines can be interpreted as evidence for a nuclear wind powered by supernovae. Observations from UV, X-ray, optical, and far-infrared bandpasses are consistent with a starburst approximately one-sixth as strong as that in M82. A scaling of the M82 models of Rieke et al. (1980) predicts that the nucleus of M83 contains 10 to the 6th - 3 x 10 to the 7th solar masses in young stars and has a supernova rate of approximately 0.01 per yr.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal, Part 2 - Letters to the Editor (ISSN 0004-637X); 274; L53-L56
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  • 67
    Publication Date: 2011-08-18
    Description: A comparison is presented of the black hole candidates LMC X-3 and Cygnus X-1 based on Einstein observations of LMC X-3 with the monitor proportional counter. A spectral analysis shows LMC X-3 to be more like the typical bright galactic X-ray source than Cygnus X-1. A search for periodic pulsations over a period range from 0.2 ms to over 1000 s set upper limits at the 90 percent confidence level of the order of 10 percent. An analysis of the aperiodic variability of LMC X-3 shows none of the shot noise behavior characteristic of Cygnus X-1. The absence of distinctive X-ray properties common to both sources suggests that the identification of black hole candidates on the basis of X-ray properties similar to Cygnus X-1 (or LMC X-3) is not reliable.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal, Part 2 - Letters to the Editor (ISSN 0004-637X); 274; L65-L69
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  • 68
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    Publication Date: 2011-08-18
    Description: The Kalnajs (1972, 1976) Omega models of global mass and velocity distributions are employed in the present two-dimensional N-body simulation, which allows for a spectrum of particle masses, stellar explosions, explosion remnant interactions with an interstellar medium, and the creation of new stars from the gas. Two sequences of runs using the Omega values of 0.8 and 0.9 examine the separate and combined effects of particle mass distribution, the gravitational influence of an interstellar gas distribution on the N-body particles, and stellar evolution, allowing for stellar explosions and star formation from the gas. It is found that both Omega values' nonequilibrium results dramatically change when evolution is allowed to occur. These results call for more realistic coupled N-body and evolution simulations in order to improve the understanding of disk galaxy evolution.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal, Part 1 (ISSN 0004-637X); 274; 595-610
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  • 69
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    Publication Date: 2011-08-18
    Description: An assessment is made of the extent to which the study of the isotropy of the X-ray sky has contributed to the present understanding of the structure of the universe at moderate redshifts. It is, of course, the anisotropic character of the sky flux that is valuable in this context. Although it is not currently possible to undertake measurements with the precision and small solid angles that are typically achieved in the microwave range, the comparatively crude limits from the X-ray fluctuations place limits on the largest scale structure of the universe. After indicating the nature of measurements made, with the HEAO 1 A-2 experiment, of the X-ray sky and its anisotropies, it is shown how these place limits on the origin of the X-ray sky and on any large scale structure of the universe.
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  • 70
    Publication Date: 2011-08-19
    Description: It is noted that it is helpful to divide the atmosphere of an early-type star into two parts: a photosphere and a mantle. The photosphere can be modeled satisfactorily by normal model-atmosphere procedures. When modeling the mantle, one must take account of the deposition of nonradiative heat and momentum and one should recognize that the mantles of hot stars do not appear to be uniform or spherically symmetric. Five areas of discrepancy between classical theory and observation are noted and a possible way of modeling the mantles of early-type stars is outlined. The model consists of arcades of magnetic loops which form helmet-type structures in the equatorial band of the star, and of coronal-hole-type structures emmanating from weak unipolar regions which are chiefly distributed at polar latitudes.
    Keywords: ASTROPHYSICS
    Type: Hvar Observatory, Bulletin (ISSN 0351-2651); 7; 1, 19
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  • 71
    Publication Date: 2011-08-19
    Description: Information about the effective temperatures, radii, and masses of O-type stars is presented. It is argued that rapid variations in the amount of light from O stars and the spectral distribution are a result chiefly of changes which occur in the envelope of the star. The stability of the photospheric layers of O stars against convection is reviewed and it is noted that late O stars and early B stars have a convection zone in the deeper parts of the photosphere. This convection zone is due to the second ionization of helium. Evidence is reviewed that most of the line-profile changes seen for O stars are generated by changes in the physical state of the mantle of the star, that is of the outer atmosphere where the deposition of non-radiative energy and momentum controls the physical state of the atmosphere. The physical state of the mantle may change in response to changes in the upper envelope of a star with a different time constant than the photosphere does.
    Keywords: ASTROPHYSICS
    Type: Hvar Observatory, Bulletin (ISSN 0351-2651); 7; 1, 19; 1-15; Di
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  • 72
    Publication Date: 2011-08-19
    Description: An analysis was conducted for into mesh oil jet lubrication with an arbitrary offset and inclination angle from the pitch point for the case where the oil jet velocity is equal to or less than pitch line velocity. The analysis includes the case for the oil jet offset from the pitch point in the direction of the pinion and where the oil jet is inclined to intersect the common pitch point. Equations were developed for the minimum oil jet velocity required to impinge on the pinion or gear and the optimum oil jet velocity to obtain the maximum impingement depth.
    Keywords: MECHANICAL ENGINEERING
    Type: ASME; 713-718
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  • 73
    Publication Date: 2011-08-18
    Description: Eight dual channel microwave radiometers were constructed as a research and development effort for the Crustal Dynamics Project and the Deep Space Network. These instruments, known as water vapor radiometers, are primarily intended to demonstrate that the variable path delay imposed by atmospheric water vapor can be calibrated in microwave tracking and distance measuring systems but could also be used in other applications involving moist air meteorology and propagation studies. They are being deployed to various stations and observatories that participate in Very Long Baseline Interferometry experiments. The development history of these instruments are reviewed, the theory of operation and overall design considerations are outlined, and the instrumental parameters and performance characteristics are described.
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    Type: The Telecommun. and Data Acquisition Rept.; p 1-19
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  • 74
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    Publication Date: 2011-08-19
    Description: In the Advanced Adiabatic Development program, the following technology were identified as critical: piston development for oil-less, adiabatic engine; positive displacement compounding and charge system; experimental evaluation of the preheat concept; combustion system with positive ignition assist; and ceramic manufacturing technology. Of these five areas, ceramic manufacturing technology is the pacing item, and is already being addressed by several organizations. Therefore the four remaining areas need immediate attention. Since the lead time involved in engine development and production is long, this technology development should be done concurrently with the AAD engine development. A four year program is outlined which will simultaneously study these first four areas. This program requires two test rigs; one single cylinder adiabatic engine; and one multicylinder adiabatic turbocompound engine.
    Keywords: MECHANICAL ENGINEERING
    Type: Advan. Automotive Diesel Assessment Program; 7 p
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  • 75
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    Publication Date: 2011-08-19
    Description: A critique of the various characteristics of engine design influencing noise and attempts to indicator areas where attention is required to obtain noise acceptable engine for automobiles are discussed. It was concluded that the engine has a potential to be quiet beccause a ion rated speed is chosen. Problems with high gas pressure, the fuel injection pump, and the expander/compressor are discussed.
    Keywords: MECHANICAL ENGINEERING
    Type: Cummins Engine Co., Inc. Advan. Automotive Diesel Assessment Program; 29 p
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  • 76
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    Publication Date: 2011-08-19
    Description: Preliminary selection and sizing of a positive displacement screw compressor-expander subsystem for a light-duty adiabatic diesel engine; development of a mathematical model to describe overall efficiencies for the screw compressor and expander; simulation of operation to establish overall efficiency for a range of design parameters and at given engine operating points; simulation to establish potential net power output at light-duty diesel operating points; analytical determination of mass moments of inertia for the rotors and inertia of the compressor-expander subsystem; and preparation of engineering layout drawings of the compressor and expander are discussed. As a result of this work, it was concluded that the screw compressor and expander designed for light-duty diesel engine applications are viable alternatives to turbo-compound systems, with acceptable efficiencies for both units, and only a moderate effect on the transient response.
    Keywords: MECHANICAL ENGINEERING
    Type: Cummins Engine Co., Inc. Advan. Automotive Diesel Assessment Program; 46 p
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  • 77
    Publication Date: 2011-08-19
    Description: The proposed design for the light duty diesel is an in-line four cylinder spark assisted diesel engine mounted transversely in the front of the vehicle. The engine has a one piece cylinder head, with one intake valve and one exhaust valve per cylinder. A flat topped piston is used with a cylindrical combustion chamber recessed into the cylinder head directly under the exhaust valve. A single ceramic insert is cast into the cylinder head to insulate both the combustion chamber and the exhaust port. A similar ceramic insert is cast into the head to insulate the intake port. A ceramic faceplate is pressed into the combustion face of the head to insulate the face of the head from hot combustion gas. The valve seats are machined directly into the ceramic faceplate for the intake valve and into the ceramic exhaust pot insert for the exhaust valve. Additional ceramic applications in the head are the use of ceramic valve guides and ceramic insulated valves. The ceramic valve guides are press fit into the head and are used for increased wear resistance. The ceramic insulated valves are conventional valves with the valve faces plasma spray coated with ceramic for insulation.
    Keywords: MECHANICAL ENGINEERING
    Type: Advan. Automotive Diesel Assessment Program; 65 p
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  • 78
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    Publication Date: 2011-08-19
    Description: A conceptual study of an advanced automotive diesel engine is discussed. The engine concept selected for vehicle installation was a supercharged 1.4 liter, 4 cylinder spark assisted diesel of 14:1 compression ratio. A compounding unit consisting of a Lysholm compressor and expander is connected to the engine crankshaft by a belt drive. The inlet air charge is heated by the expander exhaust gas via a heat exchanger. Four levels of technology achievement on the selected engine concept were evaluated, from state-of-the-art to the ideal case. This resulted in the fuel economy increasing from 53.2 mpg to 81.7 mpg, and the 0-60 mph time decreasing from 17.6 seconds to 10.9 seconds.
    Keywords: MECHANICAL ENGINEERING
    Type: Cummins Engine Co., Inc. Advan. Automotive Diesel Assessment Program; 18 p
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  • 79
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    Publication Date: 2011-08-19
    Description: The introduction of ceramics to those parts suffering high thermal loading was successfully demonstrated, and there is no question that the 100 kw (134 hp) naturally aspirated engine of the future will be developed to produce up to 300 kw (402 hp) by the application of turbocharging or its equivalent. However, at the 60 - 80 kw (80 - 107 hp) size needed for the economic automotive engine, scaling down the 300 kw (402 hp) is beset by the laws of scale. The conventional four stroke diesel was not shown to be successful at the small high speed engine size. The opposed piston two stroke engine does not suffer the same laws of scale and engines in the low power range have already been marketed successfully. The half liter/cylinder Armstrong Whitworth Swing Beam Engine is the latest to be designed with the automotive market in mind. Its low noise structure and balanced linkage system coupled with advantages for easy start and potential use of low grade fuels, derived from its variable compression ratio and slow piston motion, qualifies it for the application.
    Keywords: MECHANICAL ENGINEERING
    Type: Cummins Engine Co., Inc. Advan. Automotive Diesel Assessment Program; 3 p
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  • 80
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    Publication Date: 2011-08-19
    Description: An analysis of the frictional behavior of a roller crosshead configuration is given. This configuration consists of a piston which carries at the wristpin position a roller of large diameter which can roll on the cylinder liner surfaces. A preliminary assessment is given of whether the roller can roll on the cylinder liner without skidding, and what, if any, are the tribological implications of this approach to a dry lubricated design. The rotational speed of the roller must change during the stroke if it is not to slip on the cylinder liner. The maximum value of angular acceleration occurs at top dead center and bottom dead center. If the traction force on the rim of the roller, which is the product of the normal force due to piston side load and the coefficient of friction, is not sufficient to drive the roller through the necessary angular acceleration, sliding will occur. At 1,000 rpm, it appears that there will be a definite area of slip near each end of the stroke. The length of the area of slip may be of the order of 1/8 inch at each of these points.
    Keywords: MECHANICAL ENGINEERING
    Type: Advan. Automotive Diesel Assessment Program; 9 p
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  • 81
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    Publication Date: 2011-08-19
    Description: The objectives of this analytical study were: to select one advanced automotive diesel engine (AAD) concept which would increase the tank mileage of a 3,000 pound passenger car from the present 35 mpg to at least 52 mpg; to identify long term component research and development work required to bring the selected concept to fruition; and to prepare a development strategy that will bring the selected concept to a prototype testing phase. Cummins Engine Company has completed this study. The selected concept is a 4 stroke cycle, direct injection, spark assisted, advanced adiabatic diesel engine with positive displacement compounding plus expander and part load air preheating. The engine does not use a liquid coolant nor liquid lubricants. It is a 4 cylinder, in-line, 77 mm bore x 77 mm stroke, 1.434 liters displacement engine weighing 300 lb, and rated at 70 BHP at 3000 rpm. Installation dimensions are 621 mm length x 589 mm width x 479 mm height (24.4 inch x 22 inch x 18.9 inch).
    Keywords: MECHANICAL ENGINEERING
    Type: Advan. Automotive Diesel Assessment Program p; 59 p
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  • 82
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    Publication Date: 2011-08-19
    Description: New concepts for engine performance improvement are seen through the adoption of heat regeneration techniques; advanced methods to enhance the combustion; and higher efficiency air handling machinery, such as the positive displacement helical screw expander and compressor. Each of these concepts plays a particular role in engine performance improvement. First regeneration has a great potential for achieving higher engine thermal efficiency through the recovery of waste energy. Although the concept itself is not new (this technique is used in the gas turbine), the application to reciprocating internal combustion engines is quite unusual and presents conceptual difficulties. The second important area is better control of the combustion process in terms of heat transfer characteristics, combustion products, and heat release rate. The third area for performance improvement is in the adoption of high efficiency air handling machinery. In particular, positive displacement helical expander and compressor exhibit an extremely high efficiency over a wide range of operating conditions.
    Keywords: MECHANICAL ENGINEERING
    Type: Advan. Automotive Diesel Assessment Program; 46 p
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  • 83
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    Publication Date: 2011-08-18
    Description: The development of a numerical model for the dust environment near a comet is described. The major components of the model are a simple treatment of the acceleration of the dust by the gas outflow from an isothermal icy nucleus, a detailed treatment of the dust particle trajectories controlled by solar gravity and radiation pressure, including the formation of the dust envelope and tail, and a simple treatment of the radiation from the dust in the visible and thermal infrared. The results of recent comet observations are used to estimate parameter values for the model, including dust-to-gas ratios by light and by mass, the distribution of dust and gas emission on the nuclear surface, the distributions of dust particle size, density, mass, and radiative properties, and other quantities. Gas and dust production rates as functions of time are derived from observed light curves using the simple photometric theory. Sample results are presented for the dust concentration, flux and fluence along the trajectory of a spacecraft which flies by Comet P/Halley in 1986.
    Keywords: ASTROPHYSICS
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  • 84
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    Publication Date: 2011-08-18
    Description: A simple cometary outer ion coma model is constructed by adopting published results from numerical MHD computations. The ion composition and density distributions so derived are used to highlight some of the basic features of cometary plasma flows and the need for cometary ion observations with absolute brightness calibration.
    Keywords: ASTROPHYSICS
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  • 85
    Publication Date: 2011-08-18
    Keywords: ASTROPHYSICS
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  • 86
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    Publication Date: 2011-08-18
    Description: Observational data on the thermal emission from cometary dust grains and theoretical models constructed to explain them are reviewed. Consideration is given to grain temperature, the size distribution of the grains, thermal-emission models, the silicate component, dust-grain albedo, and icy grains; model predictions and observations are compared in graphs. It is pointed out that no unambiguous detection of icy grains has been achieved, probably because these grains are vaporized within a few hundred km of the nucleus when the comet is within 2.5 AU of the sun.
    Keywords: ASTROPHYSICS
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  • 87
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    Publication Date: 2011-08-18
    Description: The design and performance of the high-density digital recorder (HDDR) developed for use at the NASA centers (KSC, JSC, and GSFC) and at the JPL to store and retrieve 50-Mb/s PCM data streams from the Spacelab experiments are reported. The recording reproduction, and transport requirements are reviewed; and the design solutions adopted in the final version of the HDDR are described, incuding three-position-modulation and Y-phase encoding, microprocessor-controlled automatic bit synchronization and equalization, cyclic-redundancy-check error detection and correction, clock regeneration, data and clock variations, tape-speed control, and EEE-488 remote control. Reliable performance, with bit error rates 1 in 10 to the 10th forward and 1 in 10 to the 9th reverse or better and packing density up to 50 percent greater than that obtainable using conventional codes, is reported after 1.5 years of service.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
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  • 88
    Publication Date: 2011-08-18
    Description: The response to a gravitational wave of two free masses whose relative motion is monitored with an electromagnetic tracking signal is derived. The results indicate a two-feature signature in one-way data and a three-feature signature in two-way data. The effect is applied to gravitational wave experiments using laser interferometers, spacecraft Doppler tracking, planetary ranging, and pulsar timing analysis. Actual results are presented from spacecraft Doppler experiments and from pulsar timing data analysis, with new upper limits being set on a possible cosmic gravitational wave background via the pulsar data.
    Keywords: ASTROPHYSICS
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  • 89
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    Publication Date: 2011-08-18
    Description: Infrared observations of relatively isolated giant H II complexes in the LMC and the spiral arms of M33 and M101 are discussed, and complexes which extend over several kiloparsecs near the galactic centers are examined. The 30 Doradus nebula is emphasized, showing the variation of the 50-100 micron color temperature with position in that object. Ten-micron scans through the nucleus of NGC 1097 are compared to a visual photograph, showing the enhanced infrared emission which occurs at the nucleus and at the ring of H II regions about 1 kpc from the nucleus.
    Keywords: ASTROPHYSICS
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  • 90
    Publication Date: 2011-08-18
    Description: To support the development of advanced infrared remote sensing instrumentation using line and area arrays, a test facility has been developed to characterize the detectors. The necessary performance characteristics of the facility were defined by considering current and projected requirements for detector testing. The completed facility provides the desired level of detector testing capability as well as providing ease of human interaction.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
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  • 91
    Publication Date: 2011-08-18
    Description: Two comparisons of available specular infrared measurements using identical or very similar coatings reveal that specular BRDF (bidirectional reflectance distribution function) measurements of rough coatings are comparable but that simple measured reflectances are not. This is seen as indicating that the diffuse component of the measured specular reflectance is significantly larger than that of the specular component. It is noted that the diffuse component of the measurement is a convolution of the intrinsic directional reflectivity of the surface with the instrument function and that because the value of that function increases at the wavelengths under consideration, the diffuse component is larger than would otherwise be expected. The BRDF normalization is found to cause a primitive deconvolution of the instrument function and to produce a quantity that is approximately equal to the mean intrinsic directional reflectivity very near the specular direction. The analysis and comparison of data reveal that nonspecular BRDF measurements at angles well outside the instrument function can be calibrated as well by an image of the source upon the detector as by reference to a known surface.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
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  • 92
    Publication Date: 2011-08-18
    Description: An analysis is presented of the accuracy of infrared differential absorption lidar (DIAL) measurements of trace constituents in the atmosphere. Expressions are derived for the signal-to-noise ratios applicable in the detection of a signal from a scattering cell for the cases of single-detection heterodyne detection and direct detection. Results of computer simulations of the expectation value of the measured return for various measurement conditions are presented which illustrate the sensitivities of plume measurements for horizontal range-resolved and vertical content measurements of NH3 in heterodyne and direct detection. Advantages for long-range measurements of the use of rare isotope laser frequencies, tuning by collision broadening, and closely spaced on and off frequencies are pointed out.
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  • 93
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    Publication Date: 2011-08-18
    Description: Several examples of applications of coherent CO2 Doppler lidar systems are summarized to illustrate the potential of these systems. The applications discussed include the use of continuous-wave systems for detecting and tracking aircraft wake vortices, transverse velocity measurements, and measurements of mass flow rates of high stack emissions. The use of pulsed coherent lidars is illustrated by applications involving the measurement of thunderstorm gust fronts, the measurement of wind profiles, and clear air turbulence detection. Following a summary of previous efforts, some current programs are reviewed. These include investigations into two-dimensional wind field measurements, atmospheric backscatter measurements, transverse velocity measurements, and the feasibility of space operations.
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  • 94
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    Publication Date: 2011-08-18
    Description: The present investigation represents a part of a NASA program which is concerned with a study regarding the seriousness of man-made stratospheric ozone depletion. Such a depletion could possibly be caused by exhaust gases of aircraft at high altitudes or the release of chlorofluorocarbons into the lower atmosphere. A balloon-borne optical radar system was employed to conduct ozone measurements in the altitude region from 21 to 36 km and hydroxyl radical measurements in the region from 33 to 36 km. The hydroxyl radical was determined by making use of a procedure which is based on fluorescence induced by laser radiation. The technique of differential absorption lidar (DIAL) was used to measure ozone. According to this technique, two wavelengths are transmitted simultaneously and their backscattered intensities are measured. the obtained results show that optical radar represents an effective tool for stratospheric investigations.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
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  • 95
    Publication Date: 2011-08-18
    Description: The improvement in measurement uncertainty brought about by the averaging of increasing numbers of pulse return signals in both heterodyne- and direct-detection lidar systems is investigated. A theoretical analysis is presented which shows the standard deviation of the mean measurement to decrease as the inverse square root of the number of measurements, except in the presence of temporal correlation. Experimental measurements based on a dual-hybrid-TEA CO2 laser differential absorption lidar system are reported which demonstrate that the actual reduction in the standard deviation of the mean in both heterodyne- and direct-detection systems is much slower than the inverse square-root dependence predicted for uncorrelated signals, but is in agreement with predictions in the event of temporal correlation. Results thus favor the use of direct detection at relatively short range where the lower limit of the standard deviation of the mean is about 2 percent, but advantages of heterodyne detection at longer ranges are noted.
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  • 96
    Publication Date: 2011-08-18
    Description: The present investigation is concerned with differential absorption lidar techniques for remotely measuring the atmospheric temperature and pressure profile, surface pressure, and cloud top pressure-height. The procedure used in determining the pressure is based on the conduction of high-resolution measurements of absorption in the wings of lines in the oxygen A band. Absorption with respect to these areas is highly pressure sensitive in connection with the mechanism of collisional line broadening. The method of temperature measurement utilizes a determination of the absorption at the center of a selected line in the oxygen A band which originates from a quantum state with high ground state energy.
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  • 97
    Publication Date: 2011-08-18
    Description: The present investigation is concerned with the application of a pressure modulated radiometer (PMR) to the remote sensing of trace amounts of gases in the atmospheres as well as to the direct measurement of upper atmospheric winds. The PMR operates as a gas correlation spectrometer. Compared to conventional gas correlation parameters, it has some advantages which are related to greater versatility and the employment of a simpler method for maintaining electrical/optical balance. The PMR has a high sensitivity in connection with its essentially very high effective resolution. It represents a passive system and emits no radiation. A PMR is flown on Nimbus 6 which was launched in 1975. The instrument has also been used on the Nimbus 7 satellite and the Tiros N satellite.
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  • 98
    Publication Date: 2011-08-18
    Description: The present investigation is concerned with an optical radar instrument which has been developed for airborne remote sensing of atmospheric trace species at infrared wavelengths. The instrument makes use of compact, pulsed carbon dioxide lasers. It was designed for conducting differential absorption lidar (DIAL) measurements. The backscatter of laser pulse energy from the ocean and terrain surface is utilized to determine trace species column content. The instrument, which is carried by the NASA P3 aircraft, is used in a flight test program started in July 1981. The results obtained with the instrument in this program are discussed, taking into account ocean surface backscatter statistics, the ratio of ocean to terrain backscatter, the dual-wavelength correlation coefficient, the dual-wavelength cross-covariance, and the dependence of un-correlated noise variance on the mean backscatter signal.
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  • 99
    Publication Date: 2011-08-18
    Description: The pre-main sequence X-ray emitting stars observed in molecular clouds appear to provide the bulk of the ionization. Newly forming stars therefore control the coupling of the magnetic field to the cloud. Since this coupling itself is believed to be responsible for the rate of cloud collapse, it is suggested that there is a natural feedback mechanism, involving observed X-rays, which is capable of regulating molecular cloud evolution and the rate of star formation.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal, Part 2 - Letters to the Editor (ISSN 0004-637X); 272; Sept. 15
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  • 100
    Publication Date: 2011-08-18
    Description: Observed velocity-size correlations are reexamined in the light of an improved theory of turbulent energy cascade that is developed. It is shown that observed velocity-size correlations cannot be compared with the Kolmogorov law, which is based on incompressible turbulent flow. The fact that the log v-log(l/rho) scaling law (v the turbulent velocity, l the associated region size, and rho the fluid density) predicted for compressible energy cascade is always steeper than that observed in molecular clouds indicates the injection rather than the dissipation of mechanical energy at smaller scales of motion. It is also shown that the concept of strict energy cascade may not be generally applicable in the interstellar medium. The agreement between theory and observation turns out to be best for small cool clouds and cloud cores, suggesting that, for these regions at least, the dominant process in establishing the observed v-l-rho correlation is a turbulent energy cascade.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal, Part 2 - Letters to the Editor (ISSN 0004-637X); 272; Sept. 15
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