Institution
Rensselaer Polytechnic Institute
Education•Troy, New York, United States•
About: Rensselaer Polytechnic Institute is a education organization based out in Troy, New York, United States. It is known for research contribution in the topics: Terahertz radiation & Population. The organization has 19024 authors who have published 39922 publications receiving 1414699 citations. The organization is also known as: RPI & Rensselaer Institute.
Papers published on a yearly basis
Papers
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TL;DR: Visible and near IR reflectance spectra for anhydrous carbonate minerals are presented, and the use of the spectra to determine the mineralogy and gain information for the carbonate mineral is examined.
Abstract: Visible and near IR reflectance spectra for anhydrous carbonate minerals are presented, and the use of the spectra to determine the mineralogy and gaining information for the carbonate minerals is examined. Seven strong absorption bands at wavelengths greater than 1.6 microns are observed in all the spectra of anhydrous end-member carbonate minerals. The band position, intensity, and width for the carbonate bands are studied. The iron and maganese bands for the carbonate minerals are analyzed. The potential causes of spectral differences between carbonate minerals are investigated.
281 citations
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TL;DR: In this article, the hydration of soda-lime glass is studied using resonant nuclear reactions to measure the hydrogen and sodium profiles of hydrated glasses, and the measured hydration profiles are discussed in relationship to the Doremus model of interdiffusing ions.
Abstract: The hydration of soda-lime glass is studied using resonant nuclear reactions to measure the hydrogen and sodium profiles of hydrated glasses. The rate of growth of the surface layer of hydrated glass is initially proportional to the square root of time as is characteristic of diffusion controlled processes. After longer exposure a steady-state hydration profile is observed, which indicates that in addition to the diffusion controlled reaction there is a slow etching of the glass surface. The measured hydration profiles are discussed in relationship to the Doremus model of interdiffusing ions, which is found to be in good agreement with the data. This model is also discussed in relationship to measured hydration profiles of vacuum heated samples of hydrated glass.
281 citations
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281 citations
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State University of New York System1, United States Geological Survey2, Arizona State University3, University of Leicester4, California Institute of Technology5, University of Guelph6, Space Science Institute7, Los Alamos National Laboratory8, Goddard Space Flight Center9, Ames Research Center10, University of Lyon11, Mount Holyoke College12, Centre national de la recherche scientifique13, University of Toulouse14, University of New Mexico15, Smithsonian Institution16, Imperial College London17, Australian National University18, University of Nantes19, Rensselaer Polytechnic Institute20, Canadian Space Agency21, Princeton University22, Brock University23, Open University24, University of California, Davis25, Planetary Science Institute26
TL;DR: The absence of predicted geochemical variations indicates that magnetite and phyllosilicates formed by diagenesis under low-temperature, circumneutral pH, rock-dominated aqueous conditions during the early history of Mars.
Abstract: Sedimentary rocks examined by the Curiosity rover at Yellowknife Bay, Mars, were derived from sources that evolved from an approximately average martian crustal composition to one influenced by alkaline basalts. No evidence of chemical weathering is preserved, indicating arid, possibly cold, paleoclimates and rapid erosion and deposition. The absence of predicted geochemical variations indicates that magnetite and phyllosilicates formed by diagenesis under low-temperature, circumneutral pH, rock-dominated aqueous conditions. Analyses of diagenetic features (including concretions, raised ridges, and fractures) at high spatial resolution indicate that they are composed of iron- and halogen-rich components, magnesium-iron-chlorine–rich components, and hydrated calcium sulfates, respectively. Composition of a cross-cutting dike-like feature is consistent with sedimentary intrusion. The geochemistry of these sedimentary rocks provides further evidence for diverse depositional and diagenetic sedimentary environments during the early history of Mars.
281 citations
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TL;DR: In this paper, the authors used finite difference models of Fe-Mg diffusion in garnet undergoing cooling from metamorphic peak conditions to infer the significance of temperatures calculated using garnet-biotite Fe-mg exchange thermometry.
Abstract: Finite difference models of Fe-Mg diffusion in garnet undergoing cooling from metamorphic peak conditions are used to infer the significance of temperatures calculated using garnet-biotite Fe-Mg exchange thermometry. For rocks cooled from high grades where the garnet was initially homogeneous, the calculated temperature (Tcalc) using garnet core and matrix biotite depends on the size of the garnet, the ratio of garnet to biotite in the rock (Vgarnet/Vbiotite) and the cooling rate. For garnets with radii of 1 mm and Vgarnet/Vbiotite<1, Tcalc is 633, 700 and 777°C for cooling rates of 1, 10 and 100°C/Ma. For Vgarnet/Vbiotite= 1 and 4 and a cooling rate of 10° C/Ma, Tcalc is approximately 660 and 610° C, respectively. Smaller and larger garnets have lower and higher Tcalc, respectively. These results suggest that peak metamorphic temperatures may be reliably attained from rocks crystallized at conditions below Tcalc of the garnet core, provided that Vgarnet/Vbiotite is sufficiently small (<0.1) and that the composition of the biotite at the metamorphic peak has not been altered during cooling.
Numerical experiments on amphibolite facies garnets with nominal peak temperatures of 550–600° C generate a ‘well’in Fe/(Fe + Mg) near the rim during cooling. Maximum calculated temperatures for the assemblage garnet + chlorite + biotite + muscovite + plagioclase + quartz using the Fe/(Fe + Mg) at the bottom of the ‘well’with matrix biotite range from 23–43° C to 5–12° C below the peak metamorphic temperature for cooling rates of 1 and 100° C/Ma, respectively. Maximum calculated temperatures for the assemblage garnet + staurolite + biotite + muscovite + plagioclase + quartz are approximately 70° C below the peak metamorphic temperature and are not strongly dependent on cooling rate. The results of this study indicate that it may be very difficult to calculate peak metamorphic temperatures using garnet-biotite Fe-Mg exchange thermometry on amphibolite facies rocks (Tmax > 550° C) because the rim composition of the garnet, which is required to calculate the peak temperature, is that most easily destroyed by diffusion.
280 citations
Authors
Showing all 19133 results
Name | H-index | Papers | Citations |
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Pulickel M. Ajayan | 176 | 1223 | 136241 |
Zhenan Bao | 169 | 865 | 106571 |
Murray F. Brennan | 161 | 925 | 97087 |
Ashok Kumar | 151 | 5654 | 164086 |
Joseph R. Ecker | 148 | 381 | 94860 |
Bruce E. Logan | 140 | 591 | 77351 |
Shih-Fu Chang | 130 | 917 | 72346 |
Michael G. Rossmann | 121 | 594 | 53409 |
Richard P. Van Duyne | 116 | 409 | 79671 |
Michael Lynch | 112 | 422 | 63461 |
Angel Rubio | 110 | 930 | 52731 |
Alan Campbell | 109 | 687 | 53463 |
Boris I. Yakobson | 107 | 443 | 45174 |
O. C. Zienkiewicz | 107 | 455 | 71204 |
John R. Reynolds | 105 | 607 | 50027 |