449 research outputs found

    Studies on the Processing Methods for Extraterrestrial Materials

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    The literature was surveyed for high temperature mass spectrometric research on single oxides, complex oxides, and minerals in an effort to develop a means of separating elements and compounds from lunar and other extraterrestrial materials. A data acquisition system for determining vaporization rates as a function of time and temperature and software for the IEEE-488 Apple-ORTEC interface are discussed. Experimental design information from a 1000 C furnace were used with heat transfer calculations to develop the basic design for a 1600 C furnace. A controller was built for the higher temperature furnace and drawings are being made for the furnace

    On the chemical composition of L-chondrites

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    Radiochemical neutron activation analysis of Ag, As, Au, Bi, Co, Cs, Ga, In, Rb, Sb, Te, Tl, and Zn and major element data in 14 L4-6 and 3 LL5 chondrites indicates that the L group is unusually variable and may represent at least 2 subgroups differing in formation history. Chemical trends in the S/Fe rich subgroup support textural evidence indicating late loss of a shock formed Fe-Ni-S melt; the S/Fe poor subgroup seemingly reflects nebular fractionation only. Highly mobile In and Zn apparently reflect shock induced loss from L chondrites. However, contrasting chemical trends in several L chondrite sample sets indicate that these meteorites constitute a more irregular sampling of, or more heterogeneous parent material than do carbonaceous or enstatite chondrites. Data for 15 chondrites suggest higher formation temperatures and/or degrees of shock than for LL5 chondrites

    Journal of African Christian Biography

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    A publication of the Dictionary of African Christian Biography with U.S. offices located at the Center for Global Christianity and Mission at Boston University. This issue focuses on: WOMEN --- 1. Biographies of Kimpa Vita by Norbert Brockman, Mark R. Lipschutz and R. Kent Rasmussen, and Tsimba Mabiala. 2. "The Life and Visions of Krəstos Śämra, a Fifteenth-Century Ethiopian Woman Saint,"--chapter from African Christian Biography: Stories, Lives and Challenges (D. L. Robert, editor) by Wendy Laura Belcher 3. "Queen Njinga and Her Faiths: Religion and Politics in Seventeenth-Century Angola"--chapter from African Christian Biography: Stories, Lives and Challenges (D. L. Robert, editor) by Linda Heywood. 4. Book Notes, by B. Restric

    Miocene hominoids from Pakistan

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    Remains of hominoid primates collected by Yale Peabody Museum - Geological Survey of Pakistan expeditions to the Siwalik Group rocks of the Potwar Plateau, Pakistan, are described. They consist of facial, gnathic, dental, and postcranial remains of Ramapithecus, Sivapithecus, and Gigantopithecus. They are discussed anatomically and without precise taxonomic attributions. The hominoids come from 24 localities, the majority being around eight million years old. The depositional environments of 21 hominoid localities are documented in the form of microstratigraphic sections. These sections depict depositional and postdepositional features that are necessary for interpreting the facies of fossiliferous horizons. Within the predominantly fluvial Siwalik Group sediments, a three-fold division of facies is convenient for distinguishing certain taphonomic influences on hominoid and other vertebrate fossils. These facies are 1) channel, 2) channel margin, and 3) floodplain. A locality consists of one or more fossiliferous horizons, and thus one or more facies may be represented. Interpretations of the facies represented at each locality accompany the microstratigraphic sections
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