Sample records for rock laboratory ch

  1. Laboratory Spectroscopy of CH(+) and Isotopic CH

    NASA Technical Reports Server (NTRS)

    Pearson, John C.; Drouin, Brian J.

    2006-01-01

    The A1II - X1(Epsilon) electronic band of the CH(+) ion has been used as a probe of the physical and dynamical conditions of the ISM for 65 years. In spite of being one of the first molecular species observed in the ISM and the very large number of subsequent observations with large derived column densities, the pure rotational spectra of CH+ has remained elusive in both the laboratory and in the ISM as well. We report the first laboratory measurement of the pure rotation of the CH(+) ion and discuss the detection of CH-13(+) in the ISM. Also reported are the somewhat unexpected chemical conditions that resulted in laboratory production.

  2. Developing a Virtual Rock Deformation Laboratory

    NASA Astrophysics Data System (ADS)

    Zhu, W.; Ougier-simonin, A.; Lisabeth, H. P.; Banker, J. S.

    2012-12-01

    Experimental rock physics plays an important role in advancing earthquake research. Despite its importance in geophysics, reservoir engineering, waste deposits and energy resources, most geology departments in U.S. universities don't have rock deformation facilities. A virtual deformation laboratory can serve as an efficient tool to help geology students naturally and internationally learn about rock deformation. Working with computer science engineers, we built a virtual deformation laboratory that aims at fostering user interaction to facilitate classroom and outreach teaching and learning. The virtual lab is built to center around a triaxial deformation apparatus in which laboratory measurements of mechanical and transport properties such as stress, axial and radial strains, acoustic emission activities, wave velocities, and permeability are demonstrated. A student user can create her avatar to enter the virtual lab. In the virtual lab, the avatar can browse and choose among various rock samples, determine the testing conditions (pressure, temperature, strain rate, loading paths), then operate the virtual deformation machine to observe how deformation changes physical properties of rocks. Actual experimental results on the mechanical, frictional, sonic, acoustic and transport properties of different rocks at different conditions are compiled. The data acquisition system in the virtual lab is linked to the complied experimental data. Structural and microstructural images of deformed rocks are up-loaded and linked to different deformation tests. The integration of the microstructural image and the deformation data allows the student to visualize how forces reshape the structure of the rock and change the physical properties. The virtual lab is built using the Game Engine. The geological background, outstanding questions related to the geological environment, and physical and mechanical concepts associated with the problem will be illustrated on the web portal. In

  3. Synchrotron Spectroscopy and Torsional Structure of the Csh-Bending and CH3-ROCKING Bands of Methyl Mercaptan

    NASA Astrophysics Data System (ADS)

    Lees, Ronald M.; Xu, Li-Hong; Billinghurst, Brant E.

    2016-06-01

    The Fourier transform spectra of the CSH-bending and CH3-rocking infrared bands of CH3SH have been investigated at 0.001 cm-1 resolution employing synchrotron radiation at the Canadian Light Source in Saskatoon. The relative band strengths and structures are remarkably different from those for the analogous CH3OH relative, with the CSH bend being very weak and both the in-plane and out-of-plane CH3 rocks being strong with comparable intensities. The CSH bend, centered at 801.5 cm-1, has parallel a-type character with no detectable b-type component. The out-of-plane CH3 rock at 957.0 cm-1 is a purely c-type perpendicular band, whereas the in-plane rock around 1074 cm-1 is of mixed a/b character. The K-reduced vt = 0 sub-state origins for the CSH bend follow the normal oscillatory torsional pattern as a function of K with an amplitude of 0.362 cm-1, as compared to 0.653 cm-1 for the ground state and 0.801 cm-1 for the C-S stretching mode. The torsional energy curves for the out-of-plane rock are also well-behaved but are inverted, with an amplitude of 1.33 cm-1. In contrast, the sub-state origins for the in-plane rock do not display a clear oscillatory structure but are scattered over a range of about 2 cm-1, with indications of some significant perturbations. The assignments for the three bands all extend up to about K = 10 and are well-determined from GSCD relations, particularly for the a/b in-plane rock for which ΔK = 0, +1 and -1 transitions are all observed.

  4. A Virtual Rock Physics Laboratory Through Visualized and Interactive Experiments

    NASA Astrophysics Data System (ADS)

    Vanorio, T.; Di Bonito, C.; Clark, A. C.

    2014-12-01

    As new scientific challenges demand more comprehensive and multidisciplinary investigations, laboratory experiments are not expected to become simpler and/or faster. Experimental investigation is an indispensable element of scientific inquiry and must play a central role in the way current and future generations of scientist make decisions. To turn the complexity of laboratory work (and that of rocks!) into dexterity, engagement, and expanded learning opportunities, we are building an interactive, virtual laboratory reproducing in form and function the Stanford Rock Physics Laboratory, at Stanford University. The objective is to combine lectures on laboratory techniques and an online repository of visualized experiments consisting of interactive, 3-D renderings of equipment used to measure properties central to the study of rock physics (e.g., how to saturate rocks, how to measure porosity, permeability, and elastic wave velocity). We use a game creation system together with 3-D computer graphics, and a narrative voice to guide the user through the different phases of the experimental protocol. The main advantage gained in employing computer graphics over video footage is that students can virtually open the instrument, single out its components, and assemble it. Most importantly, it helps describe the processes occurring within the rock. These latter cannot be tracked while simply recording the physical experiment, but computer animation can efficiently illustrate what happens inside rock samples (e.g., describing acoustic waves, and/or fluid flow through a porous rock under pressure within an opaque core-holder - Figure 1). The repository of visualized experiments will complement lectures on laboratory techniques and constitute an on-line course offered through the EdX platform at Stanford. This will provide a virtual laboratory for anyone, anywhere to facilitate teaching/learning of introductory laboratory classes in Geophysics and expand the number of courses

  5. Laboratory investigations into fracture propagation characteristics of rock material

    NASA Astrophysics Data System (ADS)

    Prasad, B. N. V. Siva; Murthy, V. M. S. R.

    2018-04-01

    After Industrial Revolution, demand of materials for building up structures have increased enormously. Unfortunately, failures of such structures resulted in loss of life and property. Rock is anisotropic and discontinuous in nature with inherent flaws or so-called discontinuities in it. Rock is apparently used for construction in mining, civil, tunnelling, hydropower, geothermal and nuclear sectors [1]. Therefore, the strength of the structure built up considering rockmass as the construction material needs proper technical evaluation during designing stage itself to prevent and predict the scenarios of catastrophic failures due to these inherent fractures [2]. In this study, samples collected from nine different drilling sites have been investigated in laboratory for understanding the fracture propagation characteristics in rock. Rock material properties, ultrasonic velocities through pulse transmission technique and Mode I Fracture Toughness Testing of different variants of Dolomites and Graywackes are determined in laboratory and the resistance of the rock material to catastrophic crack extension or propagation has been determined. Based on the Fracture Toughness values and the rock properties, critical Energy Release Rates have been estimated. However further studies in this direction is to be carried out to understand the fracture propagation characteristics in three-dimensional space.

  6. The instantaneous rate dependence in low temperature laboratory rock friction and rock deformation experiments

    USGS Publications Warehouse

    Beeler, N.M.; Tullis, T.E.; Kronenberg, A.K.; Reinen, L.A.

    2007-01-01

    Earthquake occurrence probabilities that account for stress transfer and time-dependent failure depend on the product of the effective normal stress and a lab-derived dimensionless coefficient a. This coefficient describes the instantaneous dependence of fault strength on deformation rate, and determines the duration of precursory slip. Although an instantaneous rate dependence is observed for fracture, friction, crack growth, and low temperature plasticity in laboratory experiments, the physical origin of this effect during earthquake faulting is obscure. We examine this rate dependence in laboratory experiments on different rock types using a normalization scheme modified from one proposed by Tullis and Weeks [1987]. We compare the instantaneous rate dependence in rock friction with rate dependence measurements from higher temperature dislocation glide experiments. The same normalization scheme is used to compare rate dependence in friction to rock fracture and to low-temperature crack growth tests. For particular weak phyllosilicate minerals, the instantaneous friction rate dependence is consistent with dislocation glide. In intact rock failure tests, for each rock type considered, the instantaneous rate dependence is the same size as for friction, suggesting a common physical origin. During subcritical crack growth in strong quartzofeldspathic and carbonate rock where glide is not possible, the instantaneous rate dependence measured during failure or creep tests at high stress has long been thought to be due to crack growth; however, direct comparison between crack growth and friction tests shows poor agreement. The crack growth rate dependence appears to be higher than the rate dependence of friction and fracture by a factor of two to three for all rock types considered. Copyright 2007 by the American Geophysical Union.

  7. Muon tomography in the Mont Terri underground rock laboratory

    NASA Astrophysics Data System (ADS)

    Lesparre, N.; Gibert, D.; Marteau, J.; Carlus, B.; Nussbaum, C.

    2012-04-01

    The Mont Terri underground rock laboratory (Switzerland) was excavated in a Mesozoic shale formation constituted by Opalinus clay. This impermeable formation presents suitable properties for hosting repository sites of radioactive waste. A muon telescope has been placed in this laboratory in October 2009 to establish the feasibility of the muon tomography and to test the sensor performance in a calm environment, where we are protected from atmospheric noisy particles. However, the presence of radon in the gallery as well as charged particles issued from the decay of gamma rays may create a background noise. This noise shift and smooths the signal inducing an under estimation of the rock density. The uncorrelated background has been measured by placing the planes of detection in anti-coincidence. This estimation is preponderant and has to be combined to the theoretical feasibility evaluation to determine the best experimental set-up to observe muon flux fluctuations due to density variations. The muon densitometry experience is here exposed with the estimation of its feasibility. The data acquired from different locations inside the underground laboratory are presented. They are compared to two models representing the layer above the laboratory corresponding to a minimum and a maximum muon flux expectation depending on the values of the rock density.

  8. The First Laboratory Detection of Vibration-rotation Transitions of 12CH+ and 13CH+ and Improved Measurement of Their Rotational Transition Frequencies

    NASA Astrophysics Data System (ADS)

    Doménech, José L.; Jusko, Pavol; Schlemmer, Stephan; Asvany, Oskar

    2018-04-01

    C–H stretches of the fundamental ions CH+ and 13CH+, which have long been searched for, have been observed for the first time in the laboratory. The state-dependent attachment of He atoms to these ions at cryogenic temperatures has been exploited to obtain high-resolution rovibrational data. In addition, the lowest rotational transitions of CH+, 13CH+ and CD+ have been revisited and their rest frequency values have improved substantially.

  9. Interlaboratory comparison of δ13C and δD measurements of atmospheric CH4 for combined use of data sets from different laboratories

    NASA Astrophysics Data System (ADS)

    Umezawa, Taku; Brenninkmeijer, Carl A. M.; Röckmann, Thomas; van der Veen, Carina; Tyler, Stanley C.; Fujita, Ryo; Morimoto, Shinji; Aoki, Shuji; Sowers, Todd; Schmitt, Jochen; Bock, Michael; Beck, Jonas; Fischer, Hubertus; Michel, Sylvia E.; Vaughn, Bruce H.; Miller, John B.; White, James W. C.; Brailsford, Gordon; Schaefer, Hinrich; Sperlich, Peter; Brand, Willi A.; Rothe, Michael; Blunier, Thomas; Lowry, David; Fisher, Rebecca E.; Nisbet, Euan G.; Rice, Andrew L.; Bergamaschi, Peter; Veidt, Cordelia; Levin, Ingeborg

    2018-03-01

    We report results from a worldwide interlaboratory comparison of samples among laboratories that measure (or measured) stable carbon and hydrogen isotope ratios of atmospheric CH4 (δ13C-CH4 and δD-CH4). The offsets among the laboratories are larger than the measurement reproducibility of individual laboratories. To disentangle plausible measurement offsets, we evaluated and critically assessed a large number of intercomparison results, some of which have been documented previously in the literature. The results indicate significant offsets of δ13C-CH4 and δD-CH4 measurements among data sets reported from different laboratories; the differences among laboratories at modern atmospheric CH4 level spread over ranges of 0.5 ‰ for δ13C-CH4 and 13 ‰ for δD-CH4. The intercomparison results summarized in this study may be of help in future attempts to harmonize δ13C-CH4 and δD-CH4 data sets from different laboratories in order to jointly incorporate them into modelling studies. However, establishing a merged data set, which includes δ13C-CH4 and δD-CH4 data from multiple laboratories with desirable compatibility, is still challenging due to differences among laboratories in instrument settings, correction methods, traceability to reference materials and long-term data management. Further efforts are needed to identify causes of the interlaboratory measurement offsets and to decrease those to move towards the best use of available δ13C-CH4 and δD-CH4 data sets.

  10. The interactions of the bacterium Cupriavidus metallidurans CH34 with basalt rock, on Earth and in Space

    NASA Astrophysics Data System (ADS)

    Byloos, Bo; Van Houdt, Rob; Leys, Natalie; Ilyin, Vyacheslav; Nicholson, Natasha; Childers, Delma; Cockell, Charles; Boon, Nico

    2016-07-01

    Microbe-mineral interactions have become of interest for space exploration as microorganisms can biomine elements from extra-terrestrial materials, which could be used as nutrients in a life support system. This research is aimed at identifying the molecular mechanisms behind the interaction of Cupriavidus metallidurans CH34 with basalt, a lunar-type rock, and determining the influence of space flight conditions on this interaction. Survival and physiology of CH34 was monitored, with and without basalt, in mineral water over several months by flow cytometry, plate counts, ICP-MS, microscopy and proteomics. To study the influence of space conditions, a flight experiment on board the Russian FOTON-M4 capsule was performed. The results obtained from from water survival experiments on ground showed that CH34 was able to survive in mineral water, in the absence and presence of basalt, for several months. The total cell concentration remained stable but the cultivable fraction dropped to 10%, indicating a transition to a more dormant state. In the presence of basalt, this transition was less pronounced and cultivability was enhanced. In addition, with basalt, CH34 attached to the rock surface and formed a biofilm. The space flight experiment indicated more viable and cultivable cells compared to the ground experiment, both in the absence and presence of basalt, indicating a positive effect of space flight on survival. Chemical analysis indicated that basalt leaches out elements which may contribute to a positive effect of basalt on survival. Basalt may thus enhance survival and viability of CH34 both in ground and space flight experimental conditions. This study hopefully can contribute to a better understanding of microbe-mineral interactions, opening the door to future applications, in space, and on Earth. Acknowledgments: This work is supported by the European Space Agency (ESA-PRODEX) and the Belgian Science Policy (Belspo) through the BIOROCK project. We thank Kai

  11. ChemCam rock laser for Mars Science Laboratory "Curiosity"

    ScienceCinema

    Wiens, Roger

    2018-02-06

    Los Alamos has a long history of space-related instruments, tied primarily to its role in defense-related treaty verification. Space-based detectors have helped determine the differences between signals from lightning bolts and potential nuclear explosions. LANL-developed gamma-ray detection instruments first revealed the existence of what we now know as gamma-ray bursts, an exciting area of astrophysical research. And the use of LANL instruments on varied space missions continues with such products as the ChemCam rock laser for NASA, shown here. The Engineering Model of the ChemCam Mars Science Laboratory rover instrument arrived at NASA's Jet Propulsion Laboratory on February 6, 2008. The Flight Model was shipped in August, 2010 for installation on the rover at JPL. ChemCam will use imaging and laser-induced breakdown spectroscopy (LIBS) to determine rock and soil compositions on Mars, up to 9 meters from the rover. The engineering model is being integrated into the rover test bed for the development and testing of the rover software. The actual flight model components were concurrently assembled at Los Alamos and in Toulouse, France. The Mars Science Laboratory is scheduled to launch in 2011. Animations courtesy of JPL/NASA.

  12. ChemCam rock laser for Mars Science Laboratory "Curiosity"

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wiens, Roger

    2010-09-03

    Los Alamos has a long history of space-related instruments, tied primarily to its role in defense-related treaty verification. Space-based detectors have helped determine the differences between signals from lightning bolts and potential nuclear explosions. LANL-developed gamma-ray detection instruments first revealed the existence of what we now know as gamma-ray bursts, an exciting area of astrophysical research. And the use of LANL instruments on varied space missions continues with such products as the ChemCam rock laser for NASA, shown here. The Engineering Model of the ChemCam Mars Science Laboratory rover instrument arrived at NASA's Jet Propulsion Laboratory on February 6, 2008.more » The Flight Model was shipped in August, 2010 for installation on the rover at JPL. ChemCam will use imaging and laser-induced breakdown spectroscopy (LIBS) to determine rock and soil compositions on Mars, up to 9 meters from the rover. The engineering model is being integrated into the rover test bed for the development and testing of the rover software. The actual flight model components were concurrently assembled at Los Alamos and in Toulouse, France. The Mars Science Laboratory is scheduled to launch in 2011. Animations courtesy of JPL/NASA.« less

  13. ChemCam Rock Laser for the Mars Science Laboratory

    ScienceCinema

    LANL

    2017-12-09

    Los Alamos has a long history of space-related instr... Los Alamos has a long history of space-related instruments, tied primarily to its role in defense-related treaty verification. Space-based detectors have helped determine the differences between signals from lightning bolts and potential nuclear explosions. LANL-developed gamma-ray detection instruments first revealed the existence of what we now know as gamma-ray bursts, an exciting area of astrophysical research. And the use of LANL instruments on varied space missions continues with such products as the ChemCam rock laser for NASA, shown here. The Engineering Model of the ChemCam Mars Science Laboratory rover instrument arrived at NASA's Jet Propulsion Laboratory on February 6, 2008. ChemCam will use imaging and laser-induced breakdown spectroscopy (LIBS) to determine rock and soil compositions on Mars, up to 9 meters from the rover. The engineering model is being integrated into the rover test bed for the development and testing of the rover software. The actual flight model components are concurrently being assembled at Los Alamos and in Toulouse, France, and will be delivered to JPL in July. The Mars Science Laboratory is scheduled to launch in 2009. Animations courtesy of JPL/NASA.

  14. Infrared observations and laboratory simulations of interstellar CH_4_ and SO_2_.

    NASA Astrophysics Data System (ADS)

    Boogert, A. C. A.; Schutte, W. A.; Helmich, F. P.; Tielens, A. G. G. M.; Wooden, D. H.

    1997-02-01

    Interstellar CH_4_ may consume a fair amount of the carbon budget in dense molecular clouds, but probably less than CO, CH_3_OH, and CO_2_. However, it can only be observed at wavelength regions in the infrared that are heavily affected by the earth atmosphere. With new space and airborne missions (e.g. ISO, SOFIA) in mind we have studied the near infrared absorption spectra of solid and gaseous CH_4_. We obtained laboratory spectra of the ν_4_ deformation mode (1302cm^-1^, 7.68μm) of solid CH_4_ in astrophysically relevant mixtures. We found that the peak position and width of this absorption band vary strongly as a function of molecular environment, compared to temperature and particle shape effects. Hence, observations of this feature will provide a powerful probe of the molecular composition of interstellar ices. Also the gas phase CH_4_ ro-vibrational spectrum of the same band has been calculated. Using observed physical conditions around the protostar W 33A, we show that unresolved gaseous CH_4_ lines are detectable (at the 2-5% level) at a resolution R>1000, when the column density N>=10^16^ cm^-2^. An astrophysically relevant molecule with a very strong transition in the same wavelength regime, is SO_2_. We studied the ν _3_ asymmetric stretching mode (1319 cm^-1^, 7.58 μm) of solid SO_2_ in several mixtures, revealing that the peak position, width and detailed profile of this band are very sensitive to the molecular environment. Besides probing the composition of ice mantles, observations of solid SO_2_ will provide important information on the sulfur budget locked up in grain mantles, which is currently poorly known. We compare the laboratory and calculated spectra of CH_4_ and SO_2_ with previously published ground based spectra and new airborne observations of young stellar objects in the 7-8μm region. W 33A, NGC 7538 : IRS1 and IRS9 show a feature near 7.68μm that is consistent with absorption by solid CH_4_ or the Q-branch of gaseous CH_4_. The

  15. Deformation mechanisms and evolution of the microstructure of gouge in the Main Fault in Opalinus Clay in the Mont Terri rock laboratory (CH)

    NASA Astrophysics Data System (ADS)

    Laurich, Ben; Urai, Janos L.; Vollmer, Christian; Nussbaum, Christophe

    2018-01-01

    We studied gouge from an upper-crustal, low-offset reverse fault in slightly overconsolidated claystone in the Mont Terri rock laboratory (Switzerland). The laboratory is designed to evaluate the suitability of the Opalinus Clay formation (OPA) to host a repository for radioactive waste. The gouge occurs in thin bands and lenses in the fault zone; it is darker in color and less fissile than the surrounding rock. It shows a matrix-based, P-foliated microfabric bordered and truncated by micrometer-thin shear zones consisting of aligned clay grains, as shown with broad-ion-beam scanning electron microscopy (BIB-SEM) and optical microscopy. Selected area electron diffraction based on transmission electron microscopy (TEM) shows evidence for randomly oriented nanometer-sized clay particles in the gouge matrix, surrounding larger elongated phyllosilicates with a strict P foliation. For the first time for the OPA, we report the occurrence of amorphous SiO2 grains within the gouge. Gouge has lower SEM-visible porosity and almost no calcite grains compared to the undeformed OPA. We present two hypotheses to explain the origin of gouge in the Main Fault: (i) authigenic generation consisting of fluid-mediated removal of calcite from the deforming OPA during shearing and (ii) clay smear consisting of mechanical smearing of calcite-poor (yet to be identified) source layers into the fault zone. Based on our data we prefer the first or a combination of both, but more work is needed to resolve this. Microstructures indicate a range of deformation mechanisms including solution-precipitation processes and a gouge that is weaker than the OPA because of the lower fraction of hard grains. For gouge, we infer a more rate-dependent frictional rheology than suggested from laboratory experiments on the undeformed OPA.

  16. Microseismicity of an Unstable Rock Mass: From Field Monitoring to Laboratory Testing

    NASA Astrophysics Data System (ADS)

    Colombero, C.; Comina, C.; Vinciguerra, S.; Benson, P. M.

    2018-02-01

    The field-scale microseismic (MS) activity of an unstable rock mass is known to be an important tool to assess damage and cracking processes eventually leading to macroscopic failures. However, MS-event rates alone may not be enough for a complete understanding of the trigger mechanisms of mechanical instabilities. Acoustic Emission (AE) techniques at the laboratory scale can be used to provide complementary information. In this study, we report a MS/AE comparison to assess the stability of a granitic rock mass in the northwestern Italian Alps (Madonna del Sasso). An attempt to bridge the gap between the two different scales of observation, and the different site and laboratory conditions, is undertaken to gain insights on the rock mass behavior as a function of external governing factors. Time- and frequency-domain parameters of the MS/AE waveforms are compared and discussed with this aim. At the field scale, special attention is devoted to the correlation of the MS-event rate with meteorological parameters (air temperature and rainfalls). At the laboratory scale, AE rates, waveforms, and spectral content, recorded under controlled temperature and fluid conditions, are analyzed in order to better constrain the physical mechanisms responsible for the observed field patterns. The factors potentially governing the mechanical instability at the site were retrieved from the integration of the results. Abrupt thermal variations were identified as the main cause of the site microsesimicity, without highlighting irreversible acceleration in the MS-event rate potentially anticipating the rock mass collapse.

  17. Modeling Rock Alteration at the Water-Rock Interface of Icy Moons

    NASA Astrophysics Data System (ADS)

    Semprich, J.; Treiman, A. H.; Schwenzer, S. P.

    2018-05-01

    Alteration phases of a CM rock core are modeled with variations in fluid composition at the water-rock interface of icy moons. In the presence of H2O, CO2, CH4, and H2 serpentinization of the rock core is very likely at low pressures and 200–400 °C.

  18. Rock fragment movement in shallow rill flow - A laboratory study

    NASA Astrophysics Data System (ADS)

    Becker, Kerstin; Wirtz, Stefan; Seeger, Manuel; Gronz, Oliver; Remke, Alexander; Iserloh, Thomas; Brings, Christine; Casper, Markus; Ries, Johannes B.

    2014-05-01

    Studies concerning rill erosion mainly deal with the erosion and transport of fine material. The transport of rock fragments is examined mostly for mountain rivers. But there are important differences between the conditions and processes in rivers and in rills: (1) In most cases, the river cuts into a coarse substrate, where fine material is sparse, whereas rill erosion occurs on arable land. So the main part of the substrate is fine material and only single rock fragments influence the processes. (2) In rivers, the water depth is relatively high. There are a lot of studies about hydraulic parameters in such flows, but there is almost nothing known about hydraulic conditions in surface runoff events of a few centimeters. Additionally, little information exists about the rock fragment movement as a part of rill erosion processes on arable land. This knowledge should be increased because rock fragments cause non-stationary water turbulences in rills, which enhance the erosive force of flowing water. Field experiments can only show the fact that a certain rock fragment has moved: The starting point and the final position can be estimated. But the moving path and especially the initiation of the movement is not detectable under field conditions. Hence, we developed a laboratory setup to analyze the movement of rock fragments depending on rock fragment properties (size, form), slope gradient, flow velocity and surface roughness. By observing the rock fragments with cameras from two different angles we are able (1) to measure the rotation angles of a rock fragment during the experiment and (2) to deduce different rock fragment movement patterns. On this poster we want to present the experimental setup, developed within the scope of a master thesis, and the results of these experiments.

  19. Large rock-slope failures impacting on lakes - Reconstruction of events and deciphering mobility processes at Lake Oeschinen (CH) and Lake Eibsee (D)

    NASA Astrophysics Data System (ADS)

    Knapp, Sibylle; Anselmetti, Flavio; Gilli, Adrian; Krautblatter, Michael; Hajdas, Irka

    2017-04-01

    Among single event landslide disasters large rock-slope failures account for 75% of disasters with more than 1000 casualties. The precise determination of recurrence rates and failure volumes combined with an improved understanding of mobility processes are essential to better constrain runout models and establish early warning systems. Here we present the data sets from the two alpine regions Lake Oeschinen (CH) and Lake Eibsee (D) to show how lake studies can help to decipher the multistage character of rock-slope failures and to improve the understanding of the processes related to rock avalanche runout dynamics. We focus on such that impacted on a (paleo-) lake for two main reasons. First, the lake background sedimentation acts as a natural chronometer, which enables the stratigraphic positioning of events and helps to reconstruct the event history. This way it becomes possible to (i) decipher the multistage character of the failure of a certain rock slope and maybe detect progressive failure, (ii) determine the recurrence rates of failures at that certain rock slope, and (iii) consider energies based on estimated failure volumes, fall heights and deposition patterns. Hence, the interactions between a rock-slope failure, the water reservoir and the altered rock-slope are better understood. Second, picturing a rock avalanche running through and beyond a lake, we assume the entrainment of water and slurry to be crucial for the subsequent flow dynamics. The entrainment consumes a large share of the total energy, and orchestrates the mobility leading to fluidization, a much higher flow velocity and a longer runout-path length than expected. At Lake Oeschinen (CH) we used lake sediment cores and reflection seismic profiles in order to reconstruct the 2.5 kyrs spanning rock-slope failure history including 10 events, six of which detached from the same mountain flank, and correlated them with (pre-) historical data. The Lake Eibsee records provide insights into the

  20. Laboratory measurements of the effective-stress law of carbonate rocks under deformation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Warpinski, N.R.; Teufel, L.W.

    The behavior of rocks under the combined effects of confining stress and pore pressure is an important issue for any in situ petroleum process. In order to simplify the difficulties in dealing with two independent parameters, it is customary to introduce an effective-stress law which relates a net, or effective, stress to some combination of confining stress and pore pressure. This report documents laboratory tests of mechanical properties of five carbonate rocks.

  1. Generation of Hydrogen and Methane during Experimental Low-Temperature Reaction of Ultramafic Rocks with Water

    NASA Astrophysics Data System (ADS)

    McCollom, Thomas M.; Donaldson, Christopher

    2016-06-01

    Serpentinization of ultramafic rocks is widely recognized as a source of molecular hydrogen (H2) and methane (CH4) to support microbial activity, but the extent and rates of formation of these compounds in low-temperature, near-surface environments are poorly understood. Laboratory experiments were conducted to examine the production of H2 and CH4 during low-temperature reaction of water with ultramafic rocks and minerals. Experiments were performed by heating olivine or harzburgite with aqueous solutions at 90°C for up to 213 days in glass bottles sealed with butyl rubber stoppers. Although H2 and CH4 increased steadily throughout the experiments, the levels were very similar to those found in mineral-free controls, indicating that the rubber stoppers were the predominant source of these compounds. Levels of H2 above background were observed only during the first few days of reaction of harzburgite when CO2 was added to the headspace, with no detectable production of H2 or CH4 above background during further heating of the harzburgite or in experiments with other mineral reactants. Consequently, our results indicate that production of H2 and CH4 during low-temperature alteration of ultramafic rocks may be much more limited than some recent experimental studies have suggested. We also found no evidence to support a recent report suggesting that spinels in ultramafic rocks may stimulate H2 production. While secondary silicates were observed to precipitate during the experiments, formation of these deposits was dominated by Si released by dissolution of the glass bottles, and reaction of the primary silicate minerals appeared to be very limited. While use of glass bottles and rubber stoppers has become commonplace in experiments intended to study processes that occur during serpentinization of ultramafic rocks at low temperatures, the high levels of H2, CH4, and SiO2 released during heating indicate that these reactor materials are unsuitable for this purpose.

  2. Generation of Hydrogen and Methane during Experimental Low-Temperature Reaction of Ultramafic Rocks with Water.

    PubMed

    McCollom, Thomas M; Donaldson, Christopher

    2016-06-01

    Serpentinization of ultramafic rocks is widely recognized as a source of molecular hydrogen (H2) and methane (CH4) to support microbial activity, but the extent and rates of formation of these compounds in low-temperature, near-surface environments are poorly understood. Laboratory experiments were conducted to examine the production of H2 and CH4 during low-temperature reaction of water with ultramafic rocks and minerals. Experiments were performed by heating olivine or harzburgite with aqueous solutions at 90°C for up to 213 days in glass bottles sealed with butyl rubber stoppers. Although H2 and CH4 increased steadily throughout the experiments, the levels were very similar to those found in mineral-free controls, indicating that the rubber stoppers were the predominant source of these compounds. Levels of H2 above background were observed only during the first few days of reaction of harzburgite when CO2 was added to the headspace, with no detectable production of H2 or CH4 above background during further heating of the harzburgite or in experiments with other mineral reactants. Consequently, our results indicate that production of H2 and CH4 during low-temperature alteration of ultramafic rocks may be much more limited than some recent experimental studies have suggested. We also found no evidence to support a recent report suggesting that spinels in ultramafic rocks may stimulate H2 production. While secondary silicates were observed to precipitate during the experiments, formation of these deposits was dominated by Si released by dissolution of the glass bottles, and reaction of the primary silicate minerals appeared to be very limited. While use of glass bottles and rubber stoppers has become commonplace in experiments intended to study processes that occur during serpentinization of ultramafic rocks at low temperatures, the high levels of H2, CH4, and SiO2 released during heating indicate that these reactor materials are unsuitable for this purpose

  3. Geoengineering Research for a Deep Underground Science and Engineering Laboratory in Sedimentary Rock

    NASA Astrophysics Data System (ADS)

    Mauldon, M.

    2004-12-01

    A process to identify world-class research for a Deep Underground Science and Engineering Laboratory (DUSEL) in the USA has been initiated by NSF. While allowing physicists to study, inter alia, dark matter and dark energy, this laboratory will create unprecedented opportunities for biologists to study deep life, geoscientists to study crustal processes and geoengineers to study the behavior of rock, fluids and underground cavities at depth, on time scales of decades. A substantial portion of the nation's future infrastructure is likely to be sited underground because of energy costs, urban crowding and vulnerability of critical surface facilities. Economic and safe development of subsurface space will require an improved ability to engineer the geologic environment. Because of the prevalence of sedimentary rock in the upper continental crust, much of this subterranean infrastructure will be hosted in sedimentary rock. Sedimentary rocks are fundamentally anisotropic due to lithology and bedding, and to discontinuities ranging from microcracks to faults. Fractures, faults and bedding planes create structural defects and hydraulic pathways over a wide range of scales. Through experimentation, observation and monitoring in a sedimentary rock DUSEL, in conjunction with high performance computational models and visualization tools, we will explore the mechanical and hydraulic characteristics of layered rock. DUSEL will permit long-term experiments on 100 m blocks of rock in situ, accessed via peripheral tunnels. Rock volumes will be loaded to failure and monitored for post-peak behavior. The response of large rock bodies to stress relief-driven, time-dependent strain will be monitored over decades. Large block experiments will be aimed at measurement of fluid flow and particle/colloid transport, in situ mining (incl. mining with microbes), remediation technologies, fracture enhancement for resource extraction and large scale long-term rock mass response to induced

  4. Mont Terri Underground Rock Laboratory, Switzerland-Research Program And Key Results

    NASA Astrophysics Data System (ADS)

    Nussbaum, C. O.; Bossart, P. J.

    2012-12-01

    Argillaceous formations generally act as aquitards because of their low hydraulic conductivities. This property, together with the large retention capacity of clays for cationic contaminants and the potential for self-sealing, has brought clay formations into focus as potential host rocks for the geological disposal of radioactive waste. Excavated in the Opalinus Clay formation, the Mont Terri underground rock laboratory in the Jura Mountains of NW Switzerland is an important international test site for researching clay formations. Research is carried out in the underground facility, which is located adjacent to the security gallery of the Mont Terri motorway tunnel. Fifteen partners from European countries, USA, Canada and Japan participate in the project. The objectives of the research program are to analyze the hydrogeological, geochemical and rock mechanical properties of the Opalinus Clay, to determine the changes induced by the excavation of galleries and by heating of the rock formation, to test sealing and container emplacement techniques and to evaluate and improve suitable investigation techniques. For the safety of deep geological disposal, it is of key importance to understand the processes occurring in the undisturbed argillaceous environment, as well as the processes in a disturbed system, during the operation of the repository. The objectives are related to: 1. Understanding processes and mechanisms in undisturbed clays and 2. Experiments related to repository-induced perturbations. Experiments of the first group are dedicated to: i) Improvement of drilling and excavation technologies and sampling methods; ii) Estimation of hydrogeological, rock mechanical and geochemical parameters of the undisturbed Opalinus Clay. Upscaling of parameters from laboratory to in situ scale; iii) Geochemistry of porewater and natural gases; evolution of porewater over time scales; iv) Assessment of long-term hydraulic transients associated with erosion and thermal

  5. Scattering from Rock and Rock Outcrops

    DTIC Science & Technology

    2015-09-30

    Scattering from Rock and Rock Outcrops Derek R. Olson The Pennsylvania State University Applied Research Laboratory, P.O. Box 30 State...In terms of target detection and classification, scattering from exposed rock on the seafloor, (i.e., individual rocks and rock outcrops) presents...levels, and other statistical measures of acoustic scattering from rocks and rock outcrops is therefore critical. Unfortunately (and curiously

  6. Room-Temperature C-H Functionalization Sequence under Benchtop Conditions for the Undergraduate Chemistry Laboratory

    ERIC Educational Resources Information Center

    Chen, Shuming

    2018-01-01

    An iridium(III)-mediated C-H functionalization sequence involving a concerted cyclometalation-deprotonation/migratory insertion pathway is reported for the undergraduate chemistry laboratory. The air- and water-stable iridacycle intermediates are readily isolated and characterized by NMR spectroscopy. Both steps of the experiment are performed at…

  7. Laboratory detection of a new interstellar free radical CH2CN(2B1)

    NASA Technical Reports Server (NTRS)

    Saito, Shuji; Yamamoto, Satoshi; Irvine, W. M.; Ziurys, L. M.; Suzuki, Hiroko

    1988-01-01

    An asymmetric-top free radical CH2CN with a 2B1 ground state was detected by laboratory microwave spectroscopy. The radical was produced in a free-space absorption cell by a DC glow discharge in pure CH3CN gas. About 60 fine-structure components were observed for the N = 11-10 to 14-13 a-type rotational transitions in the frequency region of 220-260 GHz. Hyperfine resolved components for the N = 4-3 and 5-4 transitions were resolved in the 80 and 100 GHz regions, respectively. Molecular constants were determined and U100602 and U80484 from Sgr B2, and U40240 and U20120 from TMC-1 were assigned to the N = 5-4, 4-3, 2-1, and 1-0 transitions with K(-1) = 0 of the CH2CN radical.

  8. [LaboRisCh: an algorithm for assessment of health risks due to chemicals in research laboratories and similar workplaces].

    PubMed

    Strafella, Elisabetta; Bracci, M; Calisti, R; Governa, M; Santarelli, Lory

    2008-01-01

    Chemical risk assessment in research laboratories is complicated by factors such as the large number of agents to be considered, each present in small quantities, and the very short and erratic periods of exposure, all of which make reliable environmental and biological monitoring particularly difficult and at times impossible. In such environments, a preliminary evaluation procedure based on algorithms would be useful to establish the hazard potential of a given situation and to guide the appropriate intervention. The LaboRisCh model was expressly designed to assess the health risk due to chemicals in research laboratories and similar workplaces. The model is based on the calculation of the value of a synthetic single risk index for each substance and compound found in a laboratory and, subsequently, of a further synthetic single risk index for the whole laboratory or, where required, a section thereof. This makes LaboRisCh a compromise between need for information, ease of use, and resources required for the assessment. The risk index includes several items, chiefly the physical and chemical properties, intrinsic hazard potential, amount, dilution, and time of exposure to each agent; waste management; possible interactions; presence and efficiency of collective and individual protection devices, and staff training in good laboratory practices. The value of the synthetic single index corresponds to one of three areas: no risk (green), possible risk (yellow), and certain risk (red). Preliminary data confirm the model. LaboRisCh appears to be a reliable method for chemical risk assessment in research laboratories and similar workplaces.

  9. Field and laboratory investigation of acid effects on largemouth bass, rock bass, black crappie, and yellow perch

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Eaton, J.G.; Swenson, W.A.; McCormick, J.H.

    1992-01-01

    One-half of Little Rock Lake, a small seepage lake in north-central Wisconsin, was gradually acidified by additions of sulfuric acid between August 1983 and November 1990. The ambient pH (6.1) of the lake was reduced at successive 2-year intervals to pH 5.6, 5.1, and 4.7. Responses of largemouth bass Micropterus salmoides, rock bass Ambloplites rupestris, black crappie Pomoxis nigromaculatus, and yellow perch Perca flavescens populations to the pH reductions were recorded and compared to the responses of these species during in situ bioassays and laboratory toxicity tests on embryos and larvae. Laboratory results obtained for largemouth bass and rock bassmore » underestimated, black crappie results overestimated, and yellow perch results were similar to effects observed in field studies. In situ bioassays predicted field responses better than did laboratory toxicity tests. Laboratory results showed that monomeric Al concentrations of approximately 50 microgram/l, which were comparable to Al concentrations in the acidified half of the lake, altered low-pH toxicity. Reduced recruitment was observed in field populations at higher pH than that at which adult mortality was observed. The results indicate that laboratory toxicity tests with early life stages may not accurately predict field population responses and that results from laboratory tests should be field-validated whenever possible.« less

  10. Laboratory detection of the rotational-tunnelling spectrum of the hydroxymethyl radical, CH2OH

    NASA Astrophysics Data System (ADS)

    Bermudez, C.; Bailleux, S.; Cernicharo, J.

    2017-02-01

    Context. Of the two structural isomers of CH3O, methoxy is the only radical whose astronomical detection has been reported through the observation of several rotational lines at 2 and 3 mm wavelengths. Although the hydroxymethyl radical, CH2OH, is known to be thermodynamically the most stable (by 3300 cm-1), it has so far eluded rotational spectroscopy presumably because of its high chemical reactivity. Aims: Recent high-resolution ( 10 MHz) sub-Doppler rovibrationally resolved infrared spectra of CH2OH (symmetric CH stretching a-type band) provided accurate ground vibrational state rotational constants, thus reviving the quest for its millimeter-wave spectrum in laboratory and subsequently in space. Methods: The search and assignment of the rotational spectrum of this fundamental species were guided by our quantum chemical calculations and by using rotational constants derived from high-resolution IR data. The hydroxymethyl radical was produced by hydrogen abstraction from methanol by atomic chlorine. Results: Ninety-six b-type rotational transitions between the v = 0 and v = 1 tunnelling sublevels involving 25 fine-structure components of Q branches (with Ka = 1 ← 0) and 4 fine-structure components of R branches (assigned to Ka = 0 ← 1) were measured below 402 GHz. Hyperfine structure alternations due to the two identical methylenic hydrogens were observed and analysed based on the symmetry and parity of the rotational levels. A global fit including infrared and millimeter-wave lines has been conducted using Pickett's reduced axis system Hamiltonian. The recorded transitions (odd ΔKa) did not allow us to evaluate the Coriolis tunnelling interaction term. The comparison of the experimentally determined constants for both tunnelling levels with their computed values secures the long-awaited first detection of the rotational-tunnelling spectrum of this radical. In particular, a tunnelling rate of 139.73 ± 0.10 MHz (4.6609(32) × 10-3 cm-1) was obtained along

  11. Laboratory testing of a long expansion rock bolt support for energy-absorbing applications

    NASA Astrophysics Data System (ADS)

    Skrzypkowski, Krzysztof

    2018-01-01

    The main purpose of rock support and reinforcement in underground mining is to maintain excavations safe and open for their intended lifespan. The basic type of rock mass reinforcement method both in ore and hard coal mining is rock bolt support. Very often, existing bolt support systems are not always capable of providing a reliable controlled performance. Therefore, in recent years energy-absorbing bolts which are exposed to dynamic loading, for example from rock burst caused by high rock stresses, earthquakes, or blasting have appeared. In this article particular attention was paid to short and long expansion bolts. Quasi-static tests of expansion bolts were carried out at the laboratory test facility in simulated mining conditions, especially for the KGHM Polska Miedź S.A. mines. In the underground mines of the Legnica-Głogów Copper District (LGOM) the main way to protect the room excavation is rock bolt support with a length from 1.2 m to 2.6 m. Rock bolt support longer than 2.6 m is considered as additional support of excavations and is increasingly being used to reinforce the roofs. The comparisons of energy-absorbing short and long expansion bolts with a length of 1.8m, 3.6m and 5.2m were presented. In addition, for elastic and plastic range of each bolts were determined.

  12. ChIP-seq.

    PubMed

    Kim, Tae Hoon; Dekker, Job

    2018-05-01

    Owing to its digital nature, ChIP-seq has become the standard method for genome-wide ChIP analysis. Using next-generation sequencing platforms (notably the Illumina Genome Analyzer), millions of short sequence reads can be obtained. The densities of recovered ChIP sequence reads along the genome are used to determine the binding sites of the protein. Although a relatively small amount of ChIP DNA is required for ChIP-seq, the current sequencing platforms still require amplification of the ChIP DNA by ligation-mediated PCR (LM-PCR). This protocol, which involves linker ligation followed by size selection, is the standard ChIP-seq protocol using an Illumina Genome Analyzer. The size-selected ChIP DNA is amplified by LM-PCR and size-selected for the second time. The purified ChIP DNA is then loaded into the Genome Analyzer. The ChIP DNA can also be processed in parallel for ChIP-chip results. © 2018 Cold Spring Harbor Laboratory Press.

  13. The Boulby Geoscience Project Underground Research Laboratory: Initial Results of a Rock Mechanics Laboratory Testing Programme

    NASA Astrophysics Data System (ADS)

    Brain, M. J.; Petley, D. N.; Rosser, N.; Lim, M.; Sapsford, M.; Barlow, J.; Norman, E.; Williams, A.; Pybus, D.

    2009-12-01

    The Boulby Mine, which is situated on the northeast coast of England, is a major source of potash, primarily for use as a fertiliser, with a secondary product of rock salt (halite), used in highway deicing. The deposits are part of the Zechstein formation and are found at depths of between c.1100 and 1135 m below sea level. The evaporite sequence also contains a range of further lithologies, including anhydrite, dolomite and a mixed evaporate deposit. From a scientific perspective the dry, uncontaminated nature of the deposits, the range of lithologies present and the high stress conditions at the mine provide a unique opportunity to observe rock deformation in situ in varying geological and stress environments. To this end the Boulby Geoscience Project was established to examine the feasibility of developing an underground research laboratory at the mine. Information regarding the mechanical properties of the strata at the Boulby Mine is required to develop our understanding of the strength and deformation behaviour of the rock over differing timescales in response to variations in the magnitude and duration of applied stresses. As such data are currently limited, we have developed a laboratory testing programme that examines the behaviour of the deposits during the application of differential compressive stresses. We present the initial results of this testing programme here. Experiments have been carried out using a high pressure Virtual Infinite Strain (VIS) triaxial apparatus (250 kN maximum axial load; 64 MPa maximum cell pressure) manufactured by GDS Instruments. Conventional compression tests under uniaxial and triaxial conditions have been undertaken to determine the effects of axial stress application rate, axial strain rate and confining pressure on behaviour and failure mechanisms. The experimental programme also includes advanced testing into time-dependent creep behaviour under constant deviatoric stress; the effects of variations in temperature and

  14. A field and laboratory investigation of acid effects on largemouth bass, rock bass, black crappie, and yellow perch

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Eaton, J.G.; McCormick, J.H.; Swenson, W.A.

    1992-09-01

    One-half of Little Rock Lake, a small seepage lake in north-central Wisconsin, was gradually acidified by additions of sulfuric acid between August 1983 and November 1990. The ambient pH (6.1) of the lake was reduced at successive 2-year intervals to pH 5.6, 5.1, and 4.7. Responses of largemouth bass Micropterus salmoides, rock bass Ambloplites rupestris, black crappie Pomoxis nigromaculatus, and yellow perch Perca flavescens populations to the pH reductions were recorded and compared to the responses of these species during in situ bioassays and laboratory toxicity tests on embryos and larvae. Laboratory results obtained for largemouth bass and rock bassmore » underestimated, black crappie results overestimated, and yellow perch results were similar to effects observed in field studies. In situ bioassays predicted field responses better than did laboratory toxicity tests. Laboratory results showed that monomeric Al concentrations of approximately 50 [mu]g/L, which were comparable to Al concentrations in the acidified half of the lake, altered low-pH toxicity. Reduced recruitment was observed in field populations at higher pH than that at which adult mortality was observed. The results indicate that laboratory toxicity tests with early life stages may not accurately predict field population responses and that results from laboratory tests should be field-validated whenever possible. 42 refs., 2 figs., 7 tabs.« less

  15. Investigating Brittle Rock Failure and Associated Seismicity Using Laboratory Experiments and Numerical Simulations

    NASA Astrophysics Data System (ADS)

    Zhao, Qi

    Rock failure process is a complex phenomenon that involves elastic and plastic deformation, microscopic cracking, macroscopic fracturing, and frictional slipping of fractures. Understanding this complex behaviour has been the focus of a significant amount of research. In this work, the combined finite-discrete element method (FDEM) was first employed to study (1) the influence of rock discontinuities on hydraulic fracturing and associated seismicity and (2) the influence of in-situ stress on seismic behaviour. Simulated seismic events were analyzed using post-processing tools including frequency-magnitude distribution (b-value), spatial fractal dimension (D-value), seismic rate, and fracture clustering. These simulations demonstrated that at the local scale, fractures tended to propagate following the rock mass discontinuities; while at reservoir scale, they developed in the direction parallel to the maximum in-situ stress. Moreover, seismic signature (i.e., b-value, D-value, and seismic rate) can help to distinguish different phases of the failure process. The FDEM modelling technique and developed analysis tools were then coupled with laboratory experiments to further investigate the different phases of the progressive rock failure process. Firstly, a uniaxial compression experiment, monitored using a time-lapse ultrasonic tomography method, was carried out and reproduced by the numerical model. Using this combination of technologies, the entire deformation and failure processes were studied at macroscopic and microscopic scales. The results not only illustrated the rock failure and seismic behaviours at different stress levels, but also suggested several precursory behaviours indicating the catastrophic failure of the rock. Secondly, rotary shear experiments were conducted using a newly developed rock physics experimental apparatus ERDmu-T) that was paired with X-ray micro-computed tomography (muCT). This combination of technologies has significant advantages

  16. Ice chemistry of acetaldehyde reveals competitive reactions in the first step of the Strecker synthesis of alanine: formation of HO-CH(CH3)-NH2 vs. HO-CH(CH3)-CN

    NASA Astrophysics Data System (ADS)

    Fresneau, Aurélien; Danger, Grégoire; Rimola, Albert; Duvernay, Fabrice; Theulé, Patrice; Chiavassa, Thierry

    2015-08-01

    The understanding of compound formation in laboratory simulated astrophysical environments is an important challenge in obtaining information on the chemistry occurring in these environments. We here investigate by means of both laboratory experiments and quantum chemical calculations the ice-based reactivity of acetaldehyde (CH3CHO) with ammonia (NH3) and hydrogen cyanide (HCN) in excess of water (H2O) promoted by temperature. A priori, this study should give information on alanine (2HN-CH(CH3)-COOH) formation (the simplest chiral amino acid detected in meteorites), since these reactions concern the first steps of its formation through the Strecker synthesis. However, infrared spectroscopy, mass spectrometry with HC14N or HC15N isotopologues and B3LYP-D3 results converge to indicate that an H2O-dominated ice containing CH3CHO, NH3 and HCN not only leads to the formation of α-aminoethanol (2HN-CH(CH3)-OH, the product compound of the first step of the Strecker mechanism) and its related polymers (2HN-(CH(CH3)-O)n-H) due to reaction between CH3CHO and NH3, but also to the 2-hydroxypropionitrile (HO­-CH(CH3)-CN) and its related polymers (H-(O-CH(CH3))n-CN) from direct reaction between CH3CHO and HCN. The ratio between these two species depends on the initial NH3/HCN ratio in the ice. Formation of α-aminoethanol is favoured when the NH3 concentration is larger than HCN. We also show that the presence of water is essential for the formation of HO­-CH(CH3)-CN, contrarily to 2HN-CH(CH3)-OH whose formation also takes place in absence of H2O ice. As in astrophysical ices NH3 is more abundant than HCN, formation of α-aminoethanol should consequently be favoured compared to 2-hydroxypropionitrile, thus pointing out α-aminoethanol as a plausible intermediate species for alanine synthesis through the Strecker mechanism in astrophysical ices.

  17. Impact of artifact removal on ChIP quality metrics in ChIP-seq and ChIP-exo data

    PubMed Central

    Carroll, Thomas S.; Liang, Ziwei; Salama, Rafik; Stark, Rory; de Santiago, Ines

    2014-01-01

    With the advent of ChIP-seq multiplexing technologies and the subsequent increase in ChIP-seq throughput, the development of working standards for the quality assessment of ChIP-seq studies has received significant attention. The ENCODE consortium's large scale analysis of transcription factor binding and epigenetic marks as well as concordant work on ChIP-seq by other laboratories has established a new generation of ChIP-seq quality control measures. The use of these metrics alongside common processing steps has however not been evaluated. In this study, we investigate the effects of blacklisting and removal of duplicated reads on established metrics of ChIP-seq quality and show that the interpretation of these metrics is highly dependent on the ChIP-seq preprocessing steps applied. Further to this we perform the first investigation of the use of these metrics for ChIP-exo data and make recommendations for the adaptation of the NSC statistic to allow for the assessment of ChIP-exo efficiency. PMID:24782889

  18. Laboratory Detection and Analysis of Organic Compounds in Rocks Using HPLC and XRD Methods

    NASA Technical Reports Server (NTRS)

    Dragoi, D.; Kanik, I.; Bar-Cohen, Y.; Sherrit, S.; Tsapin, A.; Kulleck, J.

    2004-01-01

    In this work we describe an analytical method for determining the presence of organic compounds in rocks, limestone, and other composite materials. Our preliminary laboratory experiments on different rocks/limestone show that the organic component in mineralogical matrices is a minor phase on order of hundreds of ppm and can be better detected using high precision liquid chromatography (HPLC). The matrix, which is the major phase, plays an important role in embedding and protecting the organic molecules from the harsh Martian environment. Some rocks bear significant amounts of amino acids therefore, it is possible to identify these phases using powder x-ray diffraction (XRD) by crystallizing the organic. The method of detection/analysis of organics, in particular amino acids, that have been associated with life will be shown in the next section.

  19. The Usability of Rock-Like Materials for Numerical Studies on Rocks

    NASA Astrophysics Data System (ADS)

    Zengin, Enes; Abiddin Erguler, Zeynal

    2017-04-01

    The approaches of synthetic rock material and mass are widely used by many researchers for understanding the failure behavior of different rocks. In order to model the failure behavior of rock material, researchers take advantageous of different techniques and software. But, the majority of all these instruments are based on distinct element method (DEM). For modeling the failure behavior of rocks, and so to create a fundamental synthetic rock material model, it is required to perform related laboratory experiments for providing strength parameters. In modelling studies, model calibration processes are performed by using parameters of intact rocks such as porosity, grain size, modulus of elasticity and Poisson ratio. In some cases, it can be difficult or even impossible to acquire representative rock samples for laboratory experiments from heavily jointed rock masses and vuggy rocks. Considering this limitation, in this study, it was aimed to investigate the applicability of rock-like material (e.g. concrete) to understand and model the failure behavior of rock materials having complex inherent structures. For this purpose, concrete samples having a mixture of %65 cement dust and %35 water were utilized. Accordingly, intact concrete samples representing rocks were prepared in laboratory conditions and their physical properties such as porosity, pore size and density etc. were determined. In addition, to acquire the mechanical parameters of concrete samples, uniaxial compressive strength (UCS) tests were also performed by simultaneously measuring strain during testing. The measured physical and mechanical properties of these extracted concrete samples were used to create synthetic material and then uniaxial compressive tests were modeled and performed by using two dimensional discontinuum program known as Particle Flow Code (PFC2D). After modeling studies in PFC2D, approximately similar failure mechanism and testing results were achieved from both experimental and

  20. CH-TRU Waste Content Codes (CH-TRUCON)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Washington TRU Solutions LLC

    2007-08-15

    The CH-TRU Waste Content Codes (CH-TRUCON) document describes the inventory of the U.S. Department of Energy (DOE) CH-TRU waste within the transportation parameters specified by the Contact-Handled Transuranic Waste Authorized Methods for Payload Control (CH-TRAMPAC). The CH-TRAMPAC defines the allowable payload for the Transuranic Package Transporter-II (TRUPACT-II) and HalfPACT packagings. This document is a catalog of TRUPACT-II and HalfPACT authorized contents and a description of the methods utilized to demonstrate compliance with the CH-TRAMPAC. A summary of currently approved content codes by site is presented in Table 1. The CH-TRAMPAC describes "shipping categories" that are assigned to each payload container.more » Multiple shipping categories may be assigned to a single content code. A summary of approved content codes and corresponding shipping categories is provided in Table 2, which consists of Tables 2A, 2B, and 2C. Table 2A provides a summary of approved content codes and corresponding shipping categories for the "General Case," which reflects the assumption of a 60-day shipping period as described in the CH-TRAMPAC and Appendix 3.4 of the CH-TRU Payload Appendices. For shipments to be completed within an approximately 1,000-mile radius, a shorter shipping period of 20 days is applicable as described in the CH-TRAMPAC and Appendix 3.5 of the CH-TRU Payload Appendices. For shipments to WIPP from Los Alamos National Laboratory (LANL), Nevada Test Site, and Rocky Flats Environmental Technology Site, a 20-day shipping period is applicable. Table 2B provides a summary of approved content codes and corresponding shipping categories for "Close-Proximity Shipments" (20-day shipping period). For shipments implementing the controls specified in the CH-TRAMPAC and Appendix 3.6 of the CH-TRU Payload Appendices, a 10-day shipping period is applicable. Table 2C provides a summary of approved content codes and corresponding shipping categories for "Controlled

  1. CH-TRU Waste Content Codes (CH-TRUCON)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Washington TRU Solutions LLC

    2007-06-15

    The CH-TRU Waste Content Codes (CH-TRUCON) document describes the inventory of the U.S. Department of Energy (DOE) CH-TRU waste within the transportation parameters specified by the Contact-Handled Transuranic Waste Authorized Methods for Payload Control (CH-TRAMPAC). The CH-TRAMPAC defines the allowable payload for the Transuranic Package Transporter-II (TRUPACT-II) and HalfPACT packagings. This document is a catalog of TRUPACT-II and HalfPACT authorized contents and a description of the methods utilized to demonstrate compliance with the CH-TRAMPAC. A summary of currently approved content codes by site is presented in Table 1. The CH-TRAMPAC describes "shipping categories" that are assigned to each payload container.more » Multiple shipping categories may be assigned to a single content code. A summary of approved content codes and corresponding shipping categories is provided in Table 2, which consists of Tables 2A, 2B, and 2C. Table 2A provides a summary of approved content codes and corresponding shipping categories for the "General Case," which reflects the assumption of a 60-day shipping period as described in the CH-TRAMPAC and Appendix 3.4 of the CH-TRU Payload Appendices. For shipments to be completed within an approximately 1,000-mile radius, a shorter shipping period of 20 days is applicable as described in the CH-TRAMPAC and Appendix 3.5 of the CH-TRU Payload Appendices. For shipments to WIPP from Los Alamos National Laboratory (LANL), Nevada Test Site, and Rocky Flats Environmental Technology Site, a 20-day shipping period is applicable. Table 2B provides a summary of approved content codes and corresponding shipping categories for "Close-Proximity Shipments" (20-day shipping period). For shipments implementing the controls specified in the CH-TRAMPAC and Appendix 3.6 of the CH-TRU Payload Appendices, a 10-day shipping period is applicable. Table 2C provides a summary of approved content codes and corresponding shipping categories for "Controlled

  2. CH-TRU Waste Content Codes (CH-TRUCON)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Washington TRU Solutions LLC

    2007-09-20

    The CH-TRU Waste Content Codes (CH-TRUCON) document describes the inventory of the U.S. Department of Energy (DOE) CH-TRU waste within the transportation parameters specified by the Contact-Handled Transuranic Waste Authorized Methods for Payload Control (CH-TRAMPAC). The CH-TRAMPAC defines the allowable payload for the Transuranic Package Transporter-II (TRUPACT-II) and HalfPACT packagings. This document is a catalog of TRUPACT-II and HalfPACT authorized contents and a description of the methods utilized to demonstrate compliance with the CH-TRAMPAC. A summary of currently approved content codes by site is presented in Table 1. The CH-TRAMPAC describes "shipping categories" that are assigned to each payload container.more » Multiple shipping categories may be assigned to a single content code. A summary of approved content codes and corresponding shipping categories is provided in Table 2, which consists of Tables 2A, 2B, and 2C. Table 2A provides a summary of approved content codes and corresponding shipping categories for the "General Case," which reflects the assumption of a 60-day shipping period as described in the CH-TRAMPAC and Appendix 3.4 of the CH-TRU Payload Appendices. For shipments to be completed within an approximately 1,000-mile radius, a shorter shipping period of 20 days is applicable as described in the CH-TRAMPAC and Appendix 3.5 of the CH-TRU Payload Appendices. For shipments to WIPP from Los Alamos National Laboratory (LANL), Nevada Test Site, and Rocky Flats Environmental Technology Site, a 20-day shipping period is applicable. Table 2B provides a summary of approved content codes and corresponding shipping categories for "Close-Proximity Shipments" (20-day shipping period). For shipments implementing the controls specified in the CH-TRAMPAC and Appendix 3.6 of the CH-TRU Payload Appendices, a 10-day shipping period is applicable. Table 2C provides a summary of approved content codes and corresponding shipping categories for "Controlled

  3. CH-TRU Waste Content Codes (CH-TRUCON)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Washington TRU Solutions LLC

    2006-06-20

    The CH-TRU Waste Content Codes (CH-TRUCON) document describes the inventory of the U.S. Department of Energy (DOE) CH-TRU waste within the transportation parameters specified by the Contact-Handled Transuranic Waste Authorized Methods for Payload Control (CH-TRAMPAC). The CH-TRAMPAC defines the allowable payload for the Transuranic Package Transporter-II (TRUPACT-II) and HalfPACT packagings. This document is a catalog of TRUPACT-II and HalfPACT authorized contents and a description of the methods utilized to demonstrate compliance with the CH-TRAMPAC. A summary of currently approved content codes by site is presented in Table 1. The CH-TRAMPAC describes "shipping categories" that are assigned to each payload container.more » Multiple shipping categories may be assigned to a single content code. A summary of approved content codes and corresponding shipping categories is provided in Table 2, which consists of Tables 2A, 2B, and 2C. Table 2A provides a summary of approved content codes and corresponding shipping categories for the "General Case," which reflects the assumption of a 60-day shipping period as described in the CH-TRAMPAC and Appendix 3.4 of the CH-TRU Payload Appendices. For shipments to be completed within an approximately 1,000-mile radius, a shorter shipping period of 20 days is applicable as described in the CH-TRAMPAC and Appendix 3.5 of the CH-TRU Payload Appendices. For shipments to WIPP from Los Alamos National Laboratory (LANL), Nevada Test Site, and Rocky Flats Environmental Technology Site, a 20-day shipping period is applicable. Table 2B provides a summary of approved content codes and corresponding shipping categories for "Close-Proximity Shipments" (20-day shipping period). For shipments implementing the controls specified in the CH-TRAMPAC and Appendix 3.6 of the CH-TRU Payload Appendices, a 10-day shipping period is applicable. Table 2C provides a summary of approved content codes and corresponding shipping categories for "Controlled

  4. CH-TRU Waste Content Codes (CH-TRUCON)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Washington TRU Solutions LLC

    2006-01-18

    The CH-TRU Waste Content Codes (CH-TRUCON) document describes the inventory of the U.S. Department of Energy (DOE) CH-TRU waste within the transportation parameters specified by the Contact-Handled Transuranic Waste Authorized Methods for Payload Control (CH-TRAMPAC). The CH-TRAMPAC defines the allowable payload for the Transuranic Package Transporter-II (TRUPACT-II) and HalfPACT packagings. This document is a catalog of TRUPACT-II and HalfPACT authorized contents and a description of the methods utilized to demonstrate compliance with the CH-TRAMPAC. A summary of currently approved content codes by site is presented in Table 1. The CH-TRAMPAC describes "shipping categories" that are assigned to each payload container.more » Multiple shipping categories may be assigned to a single content code. A summary of approved content codes and corresponding shipping categories is provided in Table 2, which consists of Tables 2A, 2B, and 2C. Table 2A provides a summary of approved content codes and corresponding shipping categories for the "General Case," which reflects the assumption of a 60-day shipping period as described in the CH-TRAMPAC and Appendix 3.4 of the CH-TRU Payload Appendices. For shipments to be completed within an approximately 1,000-mile radius, a shorter shipping period of 20 days is applicable as described in the CH-TRAMPAC and Appendix 3.5 of the CH-TRU Payload Appendices. For shipments to WIPP from Los Alamos National Laboratory (LANL), Nevada Test Site, and Rocky Flats Environmental Technology Site, a 20-day shipping period is applicable. Table 2B provides a summary of approved content codes and corresponding shipping categories for "Close-Proximity Shipments" (20-day shipping period). For shipments implementing the controls specified in the CH-TRAMPAC and Appendix 3.6 of the CH-TRU Payload Appendices, a 10-day shipping period is applicable. Table 2C provides a summary of approved content codes and corresponding shipping categories for "Controlled

  5. CH-TRU Waste Content Codes (CH-TRUCON)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Washington TRU Solutions LLC

    2006-08-15

    The CH-TRU Waste Content Codes (CH-TRUCON) document describes the inventory of the U.S. Department of Energy (DOE) CH-TRU waste within the transportation parameters specified by the Contact-Handled Transuranic Waste Authorized Methods for Payload Control (CH-TRAMPAC). The CH-TRAMPAC defines the allowable payload for the Transuranic Package Transporter-II (TRUPACT-II) and HalfPACT packagings. This document is a catalog of TRUPACT-II and HalfPACT authorized contents and a description of the methods utilized to demonstrate compliance with the CH-TRAMPAC. A summary of currently approved content codes by site is presented in Table 1. The CH-TRAMPAC describes "shipping categories" that are assigned to each payload container.more » Multiple shipping categories may be assigned to a single content code. A summary of approved content codes and corresponding shipping categories is provided in Table 2, which consists of Tables 2A, 2B, and 2C. Table 2A provides a summary of approved content codes and corresponding shipping categories for the "General Case," which reflects the assumption of a 60-day shipping period as described in the CH-TRAMPAC and Appendix 3.4 of the CH-TRU Payload Appendices. For shipments to be completed within an approximately 1,000-mile radius, a shorter shipping period of 20 days is applicable as described in the CH-TRAMPAC and Appendix 3.5 of the CH-TRU Payload Appendices. For shipments to WIPP from Los Alamos National Laboratory (LANL), Nevada Test Site, and Rocky Flats Environmental Technology Site, a 20-day shipping period is applicable. Table 2B provides a summary of approved content codes and corresponding shipping categories for "Close-Proximity Shipments" (20-day shipping period). For shipments implementing the controls specified in the CH-TRAMPAC and Appendix 3.6 of the CH-TRU Payload Appendices, a 10-day shipping period is applicable. Table 2C provides a summary of approved content codes and corresponding shipping categories for "Controlled

  6. CH-TRU Waste Content Codes (CH-TRUCON)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Washington TRU Solutions LLC

    2006-12-20

    The CH-TRU Waste Content Codes (CH-TRUCON) document describes the inventory of the U.S. Department of Energy (DOE) CH-TRU waste within the transportation parameters specified by the Contact-Handled Transuranic Waste Authorized Methods for Payload Control (CH-TRAMPAC). The CH-TRAMPAC defines the allowable payload for the Transuranic Package Transporter-II (TRUPACT-II) and HalfPACT packagings. This document is a catalog of TRUPACT-II and HalfPACT authorized contents and a description of the methods utilized to demonstrate compliance with the CH-TRAMPAC. A summary of currently approved content codes by site is presented in Table 1. The CH-TRAMPAC describes "shipping categories" that are assigned to each payload container.more » Multiple shipping categories may be assigned to a single content code. A summary of approved content codes and corresponding shipping categories is provided in Table 2, which consists of Tables 2A, 2B, and 2C. Table 2A provides a summary of approved content codes and corresponding shipping categories for the "General Case," which reflects the assumption of a 60-day shipping period as described in the CH-TRAMPAC and Appendix 3.4 of the CH-TRU Payload Appendices. For shipments to be completed within an approximately 1,000-mile radius, a shorter shipping period of 20 days is applicable as described in the CH-TRAMPAC and Appendix 3.5 of the CH-TRU Payload Appendices. For shipments to WIPP from Los Alamos National Laboratory (LANL), Nevada Test Site, and Rocky Flats Environmental Technology Site, a 20-day shipping period is applicable. Table 2B provides a summary of approved content codes and corresponding shipping categories for "Close-Proximity Shipments" (20-day shipping period). For shipments implementing the controls specified in the CH-TRAMPAC and Appendix 3.6 of the CH-TRU Payload Appendices, a 10-day shipping period is applicable. Table 2C provides a summary of approved content codes and corresponding shipping categories for "Controlled

  7. CH-TRU Waste Content Codes (CH-TRUCON)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Washington TRU Solutions LLC

    2007-02-15

    The CH-TRU Waste Content Codes (CH-TRUCON) document describes the inventory of the U.S. Department of Energy (DOE) CH-TRU waste within the transportation parameters specified by the Contact-Handled Transuranic Waste Authorized Methods for Payload Control (CH-TRAMPAC). The CH-TRAMPAC defines the allowable payload for the Transuranic Package Transporter-II (TRUPACT-II) and HalfPACT packagings. This document is a catalog of TRUPACT-II and HalfPACT authorized contents and a description of the methods utilized to demonstrate compliance with the CH-TRAMPAC. A summary of currently approved content codes by site is presented in Table 1. The CH-TRAMPAC describes "shipping categories" that are assigned to each payload container.more » Multiple shipping categories may be assigned to a single content code. A summary of approved content codes and corresponding shipping categories is provided in Table 2, which consists of Tables 2A, 2B, and 2C. Table 2A provides a summary of approved content codes and corresponding shipping categories for the "General Case," which reflects the assumption of a 60-day shipping period as described in the CH-TRAMPAC and Appendix 3.4 of the CH-TRU Payload Appendices. For shipments to be completed within an approximately 1,000-mile radius, a shorter shipping period of 20 days is applicable as described in the CH-TRAMPAC and Appendix 3.5 of the CH-TRU Payload Appendices. For shipments to WIPP from Los Alamos National Laboratory (LANL), Nevada Test Site, and Rocky Flats Environmental Technology Site, a 20-day shipping period is applicable. Table 2B provides a summary of approved content codes and corresponding shipping categories for "Close-Proximity Shipments" (20-day shipping period). For shipments implementing the controls specified in the CH-TRAMPAC and Appendix 3.6 of the CH-TRU Payload Appendices, a 10-day shipping period is applicable. Table 2C provides a summary of approved content codes and corresponding shipping categories for "Controlled

  8. CH-TRU Waste Content Codes (CH-TRUCON)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Washington TRU Solutions LLC

    2006-09-15

    The CH-TRU Waste Content Codes (CH-TRUCON) document describes the inventory of the U.S. Department of Energy (DOE) CH-TRU waste within the transportation parameters specified by the Contact-Handled Transuranic Waste Authorized Methods for Payload Control (CH-TRAMPAC). The CH-TRAMPAC defines the allowable payload for the Transuranic Package Transporter-II (TRUPACT-II) and HalfPACT packagings. This document is a catalog of TRUPACT-II and HalfPACT authorized contents and a description of the methods utilized to demonstrate compliance with the CH-TRAMPAC. A summary of currently approved content codes by site is presented in Table 1. The CH-TRAMPAC describes "shipping categories" that are assigned to each payload container.more » Multiple shipping categories may be assigned to a single content code. A summary of approved content codes and corresponding shipping categories is provided in Table 2, which consists of Tables 2A, 2B, and 2C. Table 2A provides a summary of approved content codes and corresponding shipping categories for the "General Case," which reflects the assumption of a 60-day shipping period as described in the CH-TRAMPAC and Appendix 3.4 of the CH-TRU Payload Appendices. For shipments to be completed within an approximately 1,000-mile radius, a shorter shipping period of 20 days is applicable as described in the CH-TRAMPAC and Appendix 3.5 of the CH-TRU Payload Appendices. For shipments to WIPP from Los Alamos National Laboratory (LANL), Nevada Test Site, and Rocky Flats Environmental Technology Site, a 20-day shipping period is applicable. Table 2B provides a summary of approved content codes and corresponding shipping categories for "Close-Proximity Shipments" (20-day shipping period). For shipments implementing the controls specified in the CH-TRAMPAC and Appendix 3.6 of the CH-TRU Payload Appendices, a 10-day shipping period is applicable. Table 2C provides a summary of approved content codes and corresponding shipping categories for "Controlled

  9. Rock Garden

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This false color composite image of the Rock Garden shows the rocks 'Shark' and 'Half Dome' at upper left and middle, respectively. Between these two large rocks is a smaller rock (about 0.20 m wide, 0.10 m high, and 6.33 m from the Lander) that was observed close-up with the Sojourner rover (see PIA00989).

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

  10. Rock Drilling Performance Evaluation by an Energy Dissipation Based Rock Brittleness Index

    NASA Astrophysics Data System (ADS)

    Munoz, H.; Taheri, A.; Chanda, E. K.

    2016-08-01

    To reliably estimate drilling performance both tool-rock interaction laws along with a proper rock brittleness index are required to be implemented. In this study, the performance of a single polycrystalline diamond compact (PDC) cutter cutting and different drilling methods including PDC rotary drilling, roller-cone rotary drilling and percussive drilling were investigated. To investigate drilling performance by rock strength properties, laboratory PDC cutting tests were performed on different rocks to obtain cutting parameters. In addition, results of laboratory and field drilling on different rocks found elsewhere in literature were used. Laboratory and field cutting and drilling test results were coupled with values of a new rock brittleness index proposed herein and developed based on energy dissipation withdrawn from the complete stress-strain curve in uniaxial compression. To quantify cutting and drilling performance, the intrinsic specific energy in rotary-cutting action, i.e. the energy consumed in pure cutting action, and drilling penetration rate values in percussive action were used. The results show that the new energy-based brittleness index successfully describes the performance of different cutting and drilling methods and therefore is relevant to assess drilling performance for engineering applications.

  11. Time-resolved acoustic emission tomography in the laboratory: tracking localised damage in rocks

    NASA Astrophysics Data System (ADS)

    Brantut, N.

    2017-12-01

    Over the past three decades, there has been tremendous technological developments of laboratory equipment and studies using acoustic emission and ultrasonic monitoring of rock samples during deformation. Using relatively standard seismological techniques, acoustic emissions can be detected, located in space and time, and source mechanisms can be obtained. In parallel, ultrasonic velocities can be measured routinely using standard pulse-receiver techniques.Despite these major developments, current acoustic emission and ultrasonic monitoring systems are typically used separately, and the poor spatial coverage of acoustic transducers precludes performing active 3D tomography in typical laboratory settings.Here, I present an algorithm and software package that uses both passive acoustic emission data and active ultrasonic measurements to determine acoustic emission locations together with the 3D, anisotropic P-wave structure of rock samples during deformation. The technique is analogous to local earthquake tomography, but tailored to the specificities of small scale laboratory tests. The fast marching method is employed to compute the forward problem. The acoustic emission locations and the anisotropic P-wave field are jointly inverted using the Quasi-Newton method.The method is used to track the propagation of compaction bands in a porous sandstone deformed in the ductile, cataclastic flow regime under triaxial stress conditions. Near the yield point, a compaction front forms at one end of the sample, and slowly progresses towards the other end. The front is illuminated by clusters of Acoustic Emissions, and leaves behind a heavily damaged material where the P-wave speed has dropped by up to 20%.The technique opens new possibilities to track in-situ strain localisation and damage around laboratory faults, and preliminary results on quasi-static rupture in granite will be presented.

  12. Thz Spectroscopy of 12CH^+, 13CH^+, and 12CD^+

    NASA Astrophysics Data System (ADS)

    Yu, Shanshan; Drouin, Brian; Pearson, John; Amano, Takayoshi

    2015-06-01

    In 1937, Dunham detected a couple of unidentified lines in near-UV, and later Douglas and Herzberg identified them based on their laboratory observations to be low-J electronic transitions of CH^+. The electronic spectra, in particular the A^1Π-X^1σ^+ band, have been investigated extensively. On the other hand, the pure rotational transitions have not been studied so extensively. Only the lowest rotational transition, J=1-0, was observed in the laboratory for the normal species, 13CH^+, and CD^+. Based on the laboratory frequency, CH^+ was detected in star forming regions with the Hershel space observatory. Cernicharo et al identified pure rotational transitions from J=2-1 to J=6-5 in the far-infrared region in the ISO spectrum of the planetary nebula NGC 7027. The ISO spectra, however, were of low-resolution, so high-resolution spectroscopic observation is highly desirable. In this presentation, we have extended the measurements to higher-J lines up to 2 THz. For production of CH^+, an extended negative glow discharge in a gas mixture of CH_4 (˜ 0.5 mTorr) diluted in He (˜ 60 mTorr) was used. The optimum discharge current was about 15 mA and the axial magnetic filed to 160 Gauss was applied up. The discharge cell was cooled down to liquid nitrogen temperature. Several frequency multiplier chains, developed at JPL and purchased from Virginia Diodes, were used as THz radiation sources. New THz measurements are not only useful for providing better characterization of spectroscopic properties but also will serve as starting point for astronomical observations. T. Dunham, Publ. Astron. Soc. Pac., 49,~26 (1937) A. E. Douglas and G. Herzberg, Ap. J. 94,~381 (1941) T. Amano, Ap.J.Lett., 716, L1 (2010) T. Amano, J. Chem. Phys., 133, 244305 (2010) J. Cernicharo et al., Ap. J. Lett., 483, L65 (1997)

  13. Laboratory Approach to the Study of Elastic Anisotropy on Rock Samples

    NASA Astrophysics Data System (ADS)

    Pros, Z.; Lokajíček, T.; Klíma, K.

    The experimental approach (hardware and software) to the study of the elastic an isotropy of rocks on spherical samples under hydrostatic pressure up to 400 MPa is discussed. A substantial innovation of the existing measuring system and processing methods enabled us to make a detailed investigation and evaluation of the kinematic as well as dynamic parameters of elastic waves propagating through anisotropic media. The innovation is based on digital recording of the wave pattern with a high sampling density of both time and amplitude. Several options and results obtained with the innovated laboratory equipment are presented.

  14. Low-Temperature Hydrocarbon Photochemistry: CH3 + CH3 Recombination in Giant Planet Atmospheres

    NASA Technical Reports Server (NTRS)

    Smith, Gregory P.; Huestis, David L.

    2002-01-01

    Planetary emissions of the methyl radical CH3 were observed for the first time in 1998 on Saturn and Neptune by the ISO (Infrared Space Observatory) mission satellite. CH3 is produced by VUV photolysis of CH4 and is the key photochemical intermediate leading complex organic molecules on the giant planets and moons. The CH3 emissions from Saturn were unexpectedly weak. A suggested remedy is to increase the rate of the recombination reaction CH3 + CH3 + H2 --> C2H6 + H2 at 140 K to a value at least 10 times that measured at room temperature in rare gases, but within the range of disagreeing theoretical expressions at low temperature. We are performing laboratory experiments at low temperature and very low pressure. The experiments are supported by RRKM theoretical modeling that is calibrated using the extensive combustion literature.

  15. Fault Damage Zone Permeability in Crystalline Rocks from Combined Field and Laboratory Measurements

    NASA Astrophysics Data System (ADS)

    Mitchell, T.; Faulkner, D.

    2008-12-01

    In nature, permeability is enhanced in the damage zone of faults, where fracturing occurs on a wide range of scales. Here we analyze the contribution of microfracture damage on the permeability of faults that cut through low porosity, crystalline rocks by combining field and laboratory measurements. Microfracture densities surrounding strike-slip faults with well-constrained displacements ranging over 3 orders of magnitude (~0.12 m - 5000 m) have been analyzed. The faults studied are excellently exposed within the Atacama Fault Zone, where exhumation from 6-10 km has occurred. Microfractures in the form of fluid inclusion planes (FIPs) show a log-linear decrease in fracture density with perpendicular distance from the fault core. Damage zone widths defined by the density of FIPs scale with fault displacement, and an empirical relationship for microfracture density distribution throughout the damage zone with displacement is derived. Damage zone rocks will have experienced differential stresses that were less than, but some proportion of, the failure stress. As such, permeability data from progressively loaded, initially intact laboratory samples, in the pre-failure region provide useful insights into fluid flow properties of various parts of the damage zone. The permeability evolution of initially intact crystalline rocks under increasing differential load leading to macroscopic failure was determined at water pore pressures of 50 MPa and effective pressure of 10 MPa. Permeability is seen to increase by up to, and over, two orders of magnitude prior to macroscopic failure. Further experiments were stopped at various points in the loading history in order to correlate microfracture density within the samples with permeability. By combining empirical relationships determined from both quantitative fieldwork and experiments we present a model that allows microfracture permeability distribution throughout the damage zone to be determined as function of increasing fault

  16. Analysis of Copper-Bearing Rocks and Minerals for Their Metal Content Using Visible Spectroscopy: A First Year Chemistry Laboratory Exploration

    ERIC Educational Resources Information Center

    Bopegedera, A. M. R. P.

    2016-01-01

    General chemistry and introductory chemistry students were presented with a laboratory exploration for the determination of the mass percent of copper in rock and mineral samples. They worked independently in the laboratory, which involved multiple lab (pipetting, preparing standard solutions by quantitative dilution, recording visible spectra…

  17. ChIP-chip.

    PubMed

    Kim, Tae Hoon; Dekker, Job

    2018-05-01

    ChIP-chip can be used to analyze protein-DNA interactions in a region-wide and genome-wide manner. DNA microarrays contain PCR products or oligonucleotide probes that are designed to represent genomic sequences. Identification of genomic sites that interact with a specific protein is based on competitive hybridization of the ChIP-enriched DNA and the input DNA to DNA microarrays. The ChIP-chip protocol can be divided into two main sections: Amplification of ChIP DNA and hybridization of ChIP DNA to arrays. A large amount of DNA is required to hybridize to DNA arrays, and hybridization to a set of multiple commercial arrays that represent the entire human genome requires two rounds of PCR amplifications. The relative hybridization intensity of ChIP DNA and that of the input DNA is used to determine whether the probe sequence is a potential site of protein-DNA interaction. Resolution of actual genomic sites bound by the protein is dependent on the size of the chromatin and on the genomic distance between the probes on the array. As with expression profiling using gene chips, ChIP-chip experiments require multiple replicates for reliable statistical measure of protein-DNA interactions. © 2018 Cold Spring Harbor Laboratory Press.

  18. Evaluation of Rock Bolt Support for Polish Hard Rock Mines

    NASA Astrophysics Data System (ADS)

    Skrzypkowski, Krzysztof

    2018-03-01

    The article presents different types of rock bolt support used in Polish ore mining. Individual point resin and expansion rock bolt support were characterized. The roof classes for zinc and lead and copper ore mines were presented. Furthermore, in the article laboratory tests of point resin rock bolt support in a geometric scale of 1:1 with minimal fixing length of 0.6 m were made. Static testing of point resin rock bolt support were carried out on a laboratory test facility of Department of Underground Mining which simulate mine conditions for Polish ore and hard coal mining. Laboratory tests of point resin bolts were carried out, especially for the ZGH Bolesław, zinc and lead "Olkusz - Pomorzany" mine. The primary aim of the research was to check whether at the anchoring point length of 0.6 m by means of one and a half resin cartridge, the type bolt "Olkusz - 20A" is able to overcome the load.The second purpose of the study was to obtain load - displacement characteristic with determination of the elastic and plastic range of the bolt. For the best simulation of mine conditions the station steel cylinders with an external diameter of 0.1 m and a length of 0.6 m with a core of rock from the roof of the underground excavations were used.

  19. SPRUCE Methylotrophic Methanogenesis in Sphagnum-dominated Peatland Soils – CH4 and CO2 Production in Laboratory Incubations

    DOE Data Explorer

    Zalman, Cassandra A.; Meade, N.; Chanton, J.; Kostka, J. E.; Bridgham, S. D.; Keller, J. K.

    2017-12-01

    This study investigated the potential for methylotrophic methanogenesis in three Sphagnum-dominated peatland soils in northern Minnesota. Collected soils were amended with 13C-labeled traditional substrates (acetate and sodium bicarbonate/ H2) and methylated substrates (methanol, monomethylamine (“MMA”), dimethylsulfide (“DMS”)) and monitored for δ13C-CH4, δ 13C-CO2, and net CH4 and CO2 production in laboratory incubations. The peatlands included in the study were (1) the S1 Bog, home to the SPRUCE Experiment and located at the Marcell Experimental Forest (MEF, U.S. Forest Service), (2) Bog Lake Fen, also located at the MEF, and (3) Zim Bog. These sites have been described in detail previously (Medvedeff et al., 2015)

  20. Estimating the Wet-Rock P-Wave Velocity from the Dry-Rock P-Wave Velocity for Pyroclastic Rocks

    NASA Astrophysics Data System (ADS)

    Kahraman, Sair; Fener, Mustafa; Kilic, Cumhur Ozcan

    2017-07-01

    Seismic methods are widely used for the geotechnical investigations in volcanic areas or for the determination of the engineering properties of pyroclastic rocks in laboratory. Therefore, developing a relation between the wet- and dry-rock P-wave velocities will be helpful for engineers when evaluating the formation characteristics of pyroclastic rocks. To investigate the predictability of the wet-rock P-wave velocity from the dry-rock P-wave velocity for pyroclastic rocks P-wave velocity measurements were conducted on 27 different pyroclastic rocks. In addition, dry-rock S-wave velocity measurements were conducted. The test results were modeled using Gassmann's and Wood's theories and it was seen that estimates for saturated P-wave velocity from the theories fit well measured data. For samples having values of less and greater than 20%, practical equations were derived for reliably estimating wet-rock P-wave velocity as function of dry-rock P-wave velocity.

  1. Ancient microbial activity recorded in fracture fillings from granitic rocks (Äspö Hard Rock Laboratory, Sweden).

    PubMed

    Heim, C; Lausmaa, J; Sjövall, P; Toporski, J; Dieing, T; Simon, K; Hansen, B T; Kronz, A; Arp, G; Reitner, J; Thiel, V

    2012-07-01

    Fracture minerals within the 1.8-Ga-old Äspö Diorite (Sweden) were investigated for fossil traces of subterranean microbial activity. To track the potential organic and inorganic biosignatures, an approach combining complementary analytical techniques of high lateral resolution was applied to drill core material obtained at -450 m depth in the Äspö Hard Rock Laboratory. This approach included polarization microscopy, time-of-flight secondary ion mass spectrometry (ToF-SIMS), confocal Raman microscopy, electron microprobe (EMP) and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The fracture mineral succession, consisting of fluorite and low-temperature calcite, showed a thin (20-100 μm), dark amorphous layer lining the boundary between the two phases. Microscopic investigations of the amorphous layer revealed corrosion marks and, in places, branched tubular structures within the fluorite. Geochemical analysis showed significant accumulations of Si, Al, Mg, Fe and the light rare earth elements (REE) in the amorphous layer. In the same area, ToF-SIMS imaging revealed abundant, partly functionalized organic moieties, for example, C(x)H(y)⁺, C(x)H(y)N⁺, C(x)H(y)O⁺. The presence of such functionalized organic compounds was corroborated by Raman imaging showing bands characteristic of C-C, C-N and C-O bonds. According to its organic nature and the abundance of relatively unstable N- and O- heterocompounds, the organic-rich amorphous layer is interpreted to represent the remains of a microbial biofilm that established much later than the initial cooling of the Precambrian host rock. Indeed, δ¹³C, δ¹⁸O and ⁸⁷Sr/⁸⁶Sr isotope data of the fracture minerals and the host rock point to an association with a fracture reactivation event in the most recent geological past. © 2012 Blackwell Publishing Ltd.

  2. Hydrogeologic controls imposed by mechanical stratigraphy in layered rocks of the Châteauguay River Basin, a U.S.-Canada transborder aquifer

    NASA Astrophysics Data System (ADS)

    Morin, Roger; Godin, RéJean; Nastev, Miroslav; Rouleau, Alain

    2007-04-01

    The Châteauguay River Basin delineates a transborder watershed with roughly half of its surface area located in northern New York State and half in southern Québec Province, Canada. As part of a multidisciplinary study designed to characterize the hydrogeologic properties of this basin, geophysical logs were obtained in 12 wells strategically located to penetrate the four major sedimentary rock formations that constitute the regional aquifers. The layered rocks were classified according to their elastic properties into three primary units: soft sandstone, hard sandstone, and dolostone. Downhole measurements were analyzed to identify fracture patterns associated with each unit and to evaluate their role in controlling groundwater flow. Fracture networks are composed of orthogonal sets of laterally extensive, subhorizontal bedding plane partings and bed-delimited, subvertical joints with spacings that are consistent with rock mechanics principles and stress models. The vertical distribution of transmissive zones is confined to a few select bedding plane fractures, with soft sandstone having the fewest (one per 70-m depth) and hard sandstone the most (five per 70-m depth). Bed-normal permeability is examined using a probabilistic model that considers the lengths of flow paths winding along joints and bedding plane fractures. Soft sandstone has the smallest bed-normal permeability primarily because of its wide, geomechanically undersaturated joint spacing. Results indicate that the three formations have similar values of bulk transmissivity, within roughly an order of magnitude, but that each rock unit has its own unique system of groundwater flow paths that constitute that transmissivity.

  3. Predicting rock bursts in mines

    USGS Publications Warehouse

    Spall, H.

    1979-01-01

    The microseismic method relies on observational data, amply demonstrated in laboratory experiments, that acoustic noise occurs in rocks subjected to high differential stresses. Acoustic emission becomes most pronounced as the breaking strength of the rock is reached. Laboratory studies have shown that the acoustic emission is linked with the release of stored strain energy as the rock mass undergoes small-scale adjustments such as the formation of cracks. Studies in actual mines have shown that acoustic noises often precede failure of rock masses in rock bursts or in coal bumps. Seismologists are, therefore, very interested in whether these results can be applied to large-scale failures; that is, earthquakes. An active research program in predicting rock bursts in mines is being conducted by Brian T. Brady and his colleagues at the U.S Bureau of Mines, Denver Colo.  

  4. Change Analysis of Laser Scans of Laboratory Rock Slopes Subject to Wave Attack Testing

    NASA Astrophysics Data System (ADS)

    Shen, Y.; Lindenbergh, R.; Hofland, B.; Kramer, R.

    2017-09-01

    For better understanding how coastal structures with gentle slopes behave during high energy events, a wave attack experiment representing a storm of 3000 waves was performed in a flume facility. Two setups with different steepness of slope were compared under the same conditions. In order to quantify changes in the rock slopes after the wave attack, a terrestrial laser scanner was used to obtain 3D coordinates of the rock surface before and after each experiment. Next, through a series of processing steps, the point clouds were converted to a suitable 2D raster for change analysis. This allowed to estimate detailed and quantitative change information. The results indicate that the area around the artificial coast line, defined as the intersection between sloped surface and wave surface, is most strongly affected by wave attacks. As the distances from the sloped surface to the waves are shorter, changes for the mildly sloped surface, slope 1 (1 : 10), are distributed over a larger area compared to the changes for the more steeply sloped surface, slope 2 (1 : 5). The results of this experiment show that terrestrial laser scanning is an effective and feasible method for change analysis of rock slopes in a laboratory setting. Most striking results from a process point of view is that the transport direction of the rocks change between the two different slopes: from seaward transport for the steeper slope to landward transport for the milder slope.

  5. Two-wavelength single laser CH and CH(4) imaging in a lifted turbulent diffusion flame.

    PubMed

    Namazian, M; Schmitt, R L; Long, M B

    1988-09-01

    A new technique has been developed which allows simultaneous 2-D mapping of CH and CH 4 in a turbulent methane flame. A flashlamp-pumped dye laser using two back mirrors produces output at 431.5 and 444 nm simultaneously. The 431.5-nm line is used to excite the (0, 0) band of the A(2)Delta-X(2)Pi system of CH, and the fluorescence of the (0, 1) transition is observed at 489 nm. Coincidentally, the spontaneous Raman scattering from CH(4) also occurs near 489 nm for a 431.5-nm excitation. To separate the CH(4) and CH contributions, the 444-nm line is used to produce a spontaneous Raman signal from CH(4) that is spectrally separated from the CH fluorescence. Subtraction of the signals generated by the 431.5- and 444-nm wavelength beams yields separate measurements of CH(4) and CH. Raman-scattered light records the instantaneous distribution of the fuel, and simultaneously the CH fluorescence indicates the location of the flame zone. The resulting composite images provide important insight on the interrelationship between fuel-air mixing and subsequent combustion.M. Namazian is with Altex Technologies Corporation, 109 Via De Tesoros, Los Gatos, California 95030; R. L. Schmitt is with Sandia National Laboratories, Combustion Research Facility, Livermore, California 94550; and M. B. Long is with Yale University, Department of Mechanical Engineering, New Haven, Connecticut 06520.

  6. Evaluation of stress and saturation effects on seismic velocity and electrical resistivity - laboratory testing of rock samples

    NASA Astrophysics Data System (ADS)

    Vilhelm, Jan; Jirků, Jaroslav; Slavík, Lubomír; Bárta, Jaroslav

    2016-04-01

    Repository, located in a deep geological formation, is today considered the most suitable solution for disposal of spent nuclear fuel and high-level waste. The geological formations, in combination with an engineered barrier system, should ensure isolation of the waste from the environment for thousands of years. For long-term monitoring of such underground excavations special monitoring systems are developed. In our research we developed and tested monitoring system based on repeated ultrasonic time of flight measurement and electrical resistivity tomography (ERT). As a test site Bedřichov gallery in the northern Bohemia was selected. This underground gallery in granitic rock was excavated using Tunnel Boring Machine (TBM). The seismic high-frequency measurements are performed by pulse-transmission technique directly on the rock wall using one seismic source and three receivers in the distances of 1, 2 and 3 m. The ERT measurement is performed also on the rock wall using 48 electrodes. The spacing between electrodes is 20 centimeters. An analysis of relation of seismic velocity and electrical resistivity on water saturation and stress state of the granitic rock is necessary for the interpretation of both seismic monitoring and ERT. Laboratory seismic and resistivity measurements were performed. One series of experiments was based on uniaxial loading of dry and saturated granitic samples. The relation between stress state and ultrasonic wave velocities was tested separately for dry and saturated rock samples. Other experiments were focused on the relation between electrical resistivity of the rock sample and its saturation level. Rock samples with different porosities were tested. Acknowledgments: This work was partially supported by the Technology Agency of the Czech Republic, project No. TA 0302408

  7. Reduced gas seepages in ophiolitic complexes: Evidences for multiple origins of the H2-CH4-N2 gas mixtures

    NASA Astrophysics Data System (ADS)

    Vacquand, Christèle; Deville, Eric; Beaumont, Valérie; Guyot, François; Sissmann, Olivier; Pillot, Daniel; Arcilla, Carlo; Prinzhofer, Alain

    2018-02-01

    This paper proposes a comparative study of reduced gas seepages occurring in ultrabasic to basic rocks outcropping in ophiolitic complexes based on the study of seepages from Oman, the Philippines, Turkey and New Caledonia. This study is based on analyses of the gas chemical composition, noble gases contents, stable isotopes of carbon, hydrogen and nitrogen. These seepages are mostly made of mixtures of three main components which are H2, CH4 and N2 in various proportions. The relative contents of the three main gas components show 4 distinct types of gas mixtures (H2-rich, N2-rich, N2-H2-CH4 and H2-CH4). These types are interpreted as reflecting different zones of gas generation within or below the ophiolitic complexes. In the H2-rich type, associated noble gases display signatures close to the value of air. In addition to the atmospheric component, mantle and crustal contributions are present in the N2-rich, N2-H2-CH4 and H2-CH4 types. H2-bearing gases are either associated with ultra-basic (pH 10-12) spring waters or they seep directly in fracture systems from the ophiolitic rocks. In ophiolitic contexts, ultrabasic rocks provide an adequate environment with available Fe2+ and alkaline conditions that favor H2 production. CH4 is produced either directly by reaction of dissolved CO2 with basic-ultrabasic rocks during the serpentinization process or in a second step by H2-CO2 interaction. H2 is present in the gas when no more carbon is available in the system to generate CH4. The N2-rich type is notably associated with relatively high contents of crustal 4He and in this gas type N2 is interpreted as issued mainly from sediments located below the ophiolitic units.

  8. Biofiltration of methane using hybrid mixtures of biochar, lava rock and compost.

    PubMed

    La, Helen; Hettiaratchi, J Patrick A; Achari, Gopal; Verbeke, Tobin J; Dunfield, Peter F

    2018-05-21

    Using hybrid packing materials in biofiltration systems takes advantage of both the inorganic and organic properties offered by the medium including structural stability and a source of available nutrients, respectively. In this study, hybrid mixtures of compost with either lava rock or biochar in four different mixture ratios were compared against 100% compost in a methane biofilter with active aeration at two ports along the height of the biofilter. Biochar outperformed lava rock as a packing material by providing the added benefit of participating in sorption reactions with CH 4 . This study provides evidence that a 7:1 volumetric mixture of biochar and compost can successfully remove up to 877 g CH 4 /m 3 ·d with empty-bed residence times of 82.8 min. Low-affinity methanotrophs were responsible for the CH 4 removal in these systems (K M(app) ranging from 5.7 to 42.7 µM CH 4 ). Sequencing of 16S rRNA gene amplicons indicated that Gammaproteobacteria methanotrophs, especially members of the genus Methylobacter, were responsible for most of the CH 4 removal. However, as the compost medium was replaced with more inert medium, there was a decline in CH 4 removal efficiency coinciding with an increased dominance of Alphaproteobacteria methanotrophs like Methylocystis and Methylocella. As a biologically-active material, compost served as the sole source of nutrients and inoculum for the biofilters which greatly simplified the operation of the system. Higher elimination capacities may be possible with higher compost content such as a 1:1 ratio of either biochar or lava rock, while maintaining the empty-bed residence time at 82.8 min. Copyright © 2018 Elsevier Ltd. All rights reserved.

  9. Laboratory Experiments to Evaluate Matrix Diffusion of Dissolved Organic Carbon Carbon-14 in Southern Nevada Fractured-rock Aquifers

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hershey, Ronald L.; Fereday, Wyatt

    Dissolved inorganic carbon (DIC) carbon-14 ( 14C) is used to estimate groundwater ages by comparing the DIC 14C content in groundwater in the recharge area to the DIC 14C content in the downgradient sampling point. However, because of chemical reactions and physical processes between groundwater and aquifer rocks, the amount of DIC 14C in groundwater can change and result in 14C loss that is not because of radioactive decay. This loss of DIC 14C results in groundwater ages that are older than the actual groundwater ages. Alternatively, dissolved organic carbon (DOC) 14C in groundwater does not react chemically with aquifermore » rocks, so DOC 14C ages are generally younger than DIC 14C ages. In addition to chemical reactions, 14C ages may also be altered by the physical process of matrix diffusion. The net effect of a continuous loss of 14C to the aquifer matrix by matrix diffusion and then radioactive decay is that groundwater appears to be older than it actually is. Laboratory experiments were conducted to measure matrix diffusion coefficients for DOC 14C in volcanic and carbonate aquifer rocks from southern Nevada. Experiments were conducted using bromide (Br-) as a conservative tracer and 14C-labeled trimesic acid (TMA) as a surrogate for groundwater DOC. Outcrop samples from six volcanic aquifers and five carbonate aquifers in southern Nevada were used. The average DOC 14C matrix diffusion coefficient for volcanic rocks was 2.9 x 10 -7 cm 2/s, whereas the average for carbonate rocks was approximately the same at 1.7 x 10 -7 cm 2/s. The average Br- matrix diffusion coefficient for volcanic rocks was 10.4 x 10 -7 cm 2/s, whereas the average for carbonate rocks was less at 6.5 x 10 -7 cm 2/s. Carbonate rocks exhibited greater variability in DOC 14C and Br- matrix diffusion coefficients than volcanic rocks. These results confirmed, at the laboratory scale, that the diffusion of DOC 14C into southern Nevada volcanic and carbonate aquifers is slower than DIC 14C

  10. Opportunities for Multidisciplinary Research in Partnership with Rock Engineers at the Deep Underground Science and Engineering Laboratory

    NASA Astrophysics Data System (ADS)

    Laughton, C.

    2008-12-01

    For the last half century the physics community has increasingly turned to the use of underground space to conduct basic research. The community is currently planning to conduct a new generation of underground experiments at the Deep Underground Science and Engineering Laboratory (DUSEL). DUSEL will be constructed within the footprint of the defunct Homestake Gold Mine, located in Lead, South Dakota. Physics proposals call for the construction of new caverns in which to conduct major new experiments. Some of the proposed laboratory facilities will be significantly larger and deeper than any previously constructed. The talk will highlight possible opportunities for integrating multi-disciplinary research in to the cavern construction program, and will stress the need to work closely with design and construction contractors to ensure that research goals can be achieve with minimal impact on project work. The constructors of large caverns should be particularly receptive to, and encouraging of geoscience research that could improve the engineering characterization of the rock mass. An improved understanding of the rock mass, as the host construction material, would result in a more reliable cavern design and construction process, and a reduced construction risk to the Project.

  11. Reduced gas seepages in serpentinized peridotite complexes: Evidences for multiple origins of the H2-CH4-N2 gas mixtures

    NASA Astrophysics Data System (ADS)

    Deville, E.; Vacquand, C.; Beaumont, V.; Francois, G.; Sissmann, O.; Pillot, D.; Arcilla, C. A.; Prinzhofer, A.

    2017-12-01

    A comparative study of reduced gas seepages associated to serpentinized ultrabasic rocks was conducted in the ophiolitic complexes of Oman, the Philippines, Turkey and New Caledonia. This study is based on analyzes of the gas chemical composition, noble gases contents, and stable isotopes of carbon, hydrogen and nitrogen. These gas seepages are mostly made of mixtures of three main components which are H2, CH4 and N2 in various proportions. The relative contents of the three main gas components show 4 distinct families of gas mixtures (H2-rich, N2-rich, N2-H2-CH4 and H2-CH4). These families are interpreted as reflecting different zones of gas generation within or below the ophiolitic complexes. In the H2-rich family associated noble gases display signatures close to the value of air. In addition to the atmospheric component, mantle and crustal contributions are present in the N2-rich, N2-H2-CH4 and H2-CH4 families. H2-bearing gases are either associated to ultra-basic (pH 10-12) spring waters or they seep directly in fracture systems from the ophiolitic rocks. In ophiolitic contexts, ultrabasic rocks provide an adequate environment with available Fe2+ and high pH conditions that favor H2 production. CH4 is produced either directly by reaction of dissolved CO2 with basic-ultrabasic rocks during the serpentinization process or in a second step by H2-CO2 interaction. H2 is present in the gas when no more carbon is available in the system to generate CH4 (conditions of strong carbon restriction). The N2-rich family is associated with relatively high contents of crustal 4He. In this family N2 is interpreted as issued mainly from sediments located below the ophiolitic units.

  12. Reconstruction of multistage massive rock slope failure: Polymethodical approach in Lake Oeschinen (CH)

    NASA Astrophysics Data System (ADS)

    Knapp, Sibylle; Gilli, Adrian; Anselmetti, Flavio S.; Hajdas, Irka

    2016-04-01

    Lateglacial and Holocene rock-slope failures occur often as multistage failures where paraglacial adjustment and stress adaptation are hypothesised to control stages of detachment. However, we have only limited datasets to reconstruct detailed stages of large multistage rock-slope failures, and still aim at improving our models in terms of geohazard assessment. Here we use lake sediments, well-established for paleoclimate and paleoseismological reconstruction, with a focus on the reconstruction of rock-slope failures. We present a unique inventory from Lake Oeschinen (Bernese Alps, Switzerland) covering about 2.4 kyrs of rock-slope failure history. The lake sediments have been analysed using sediment-core analysis, radiocarbon dating and seismic-to-core and core-to-core correlations, and these were linked to historical and meteorological records. The results imply that the lake is significantly younger than the ~9 kyrs old Kandersteg rock avalanche (Tinner et al., 2005) and shows multiple rock-slope failures, two of which could be C14-dated. Several events detached from the same area potentially initiated by prehistoric earthquakes (Monecke et al., 2006) and later from stress relaxation processes. The data imply unexpected short recurrence rates that can be related to certain detachment scarps and also help to understand the generation of a historical lake-outburst flood. Here we show how polymethodical analysis of lake sediments can help to decipher massive multistage rock-slope failure. References Monecke, K., Anselmetti, F.S., Becker, A., Schnellmann, M., Sturm, M., Giardini, D., 2006. Earthquake-induced deformation structures in lake deposits: A Late Pleistocene to Holocene paleoseismic record for Central Switzerland. Eclogae Geologicae Helvetiae, 99(3), 343-362. Tinner, W., Kaltenrieder, P., Soom, M., Zwahlen, P., Schmidhalter, M., Boschetti, A., Schlüchter, C., 2005. Der nacheiszeitliche Bergsturz im Kandertal (Schweiz): Alter und Auswirkungen auf die

  13. Minerals associated with biofilms occurring on exposed rock in a granitic underground research laboratory.

    PubMed

    Brown, D A; Kamineni, D C; Sawicki, J A; Beveridge, T J

    1994-09-01

    The concept of disposal of nuclear fuel waste in crystalline rock requires the effects of microbial action to be investigated. The Underground Research Laboratory excavated in a pluton of the Canadian Shield provides a unique opportunity to study these effects. Three biofilms kept moist by seepage through fractures in granitic rock faces of the Underground Research Laboratory have been examined. The biofilms contained a variety of gram-negative and gram-positive morphotypes held together by an organic extracellular matrix. Nutrient levels in the groundwater were low, but energy-dispersive X-ray spectroscopy has shown biogeochemical immobilization of several elements in the biofilms; some of these elements were concentrated from extremely dilute environmental concentrations, and all elements were chemically complexed together to form amorphous or crystalline fine-grained minerals. These were seen by transmission electron microscopy to be both associated with the surfaces of the bacteria and scattered throughout the extracellular matrix, suggesting their de novo development through bacterial surface-mediated nucleation. The biofilm consortia are thought to concentrate elements both by passive sorption and by energy metabolism. By Mössbauer spectroscopy and X-ray diffraction, one of the biofilms showed that iron was both oxidized and precipitated as ferrihydrite or hematite aerobically and reduced and precipitated as siderite anaerobically. We believe that some Archean banded-iron formations could have been formed in a manner similar to this, as it would explain the deposition of hematite and siderite in close proximity. This biogeochemical development of minerals may also affect the transport of material in waste disposal sites.

  14. Minerals Associated with Biofilms Occurring on Exposed Rock in a Granitic Underground Research Laboratory

    PubMed Central

    Brown, D. Ann; Kamineni, D. Choudari; Sawicki, Jerzy A.; Beveridge, Terry J.

    1994-01-01

    The concept of disposal of nuclear fuel waste in crystalline rock requires the effects of microbial action to be investigated. The Underground Research Laboratory excavated in a pluton of the Canadian Shield provides a unique opportunity to study these effects. Three biofilms kept moist by seepage through fractures in granitic rock faces of the Underground Research Laboratory have been examined. The biofilms contained a variety of gram-negative and gram-positive morphotypes held together by an organic extracellular matrix. Nutrient levels in the groundwater were low, but energy-dispersive X-ray spectroscopy has shown biogeochemical immobilization of several elements in the biofilms; some of these elements were concentrated from extremely dilute environmental concentrations, and all elements were chemically complexed together to form amorphous or crystalline fine-grained minerals. These were seen by transmission electron microscopy to be both associated with the surfaces of the bacteria and scattered throughout the extracellular matrix, suggesting their de novo development through bacterial surface-mediated nucleation. The biofilm consortia are thought to concentrate elements both by passive sorption and by energy metabolism. By Mössbauer spectroscopy and X-ray diffraction, one of the biofilms showed that iron was both oxidized and precipitated as ferrihydrite or hematite aerobically and reduced and precipitated as siderite anaerobically. We believe that some Archean banded-iron formations could have been formed in a manner similar to this, as it would explain the deposition of hematite and siderite in close proximity. This biogeochemical development of minerals may also affect the transport of material in waste disposal sites. Images PMID:16349374

  15. Quantifying rock mass strength degradation in coastal rock cliffs

    NASA Astrophysics Data System (ADS)

    Brain, Matthew; Lim, Michael; Rosser, Nick; Petley, David; Norman, Emma; Barlow, John

    2010-05-01

    Although rock cliffs are generally perceived to evolve through undercutting and cantilever collapse of material, the recent application of high-resolution three-dimensional monitoring techniques has suggested that the volumetric losses recorded from layers above the intertidal zone produce an equally significant contribution to cliff behaviour. It is therefore important to understand the controls on rockfalls in such layers. Here we investigate the progressive influence of subaerial exposure and weathering on the geotechnical properties of the rocks encountered within the geologically complex coastal cliffs of the northeast coast of England, UK. Through a program of continuous in situ monitoring of local environmental and tidal conditions and laboratory rock strength testing, we aim to better quantify the relationships between environmental processes and the geotechnical response of the cliff materials. We have cut fresh (not previously exposed) samples from the three main rock types (sandstone, mudstone and shale) found within the cliff to uniform size, shape and volume, thus minimizing variability and removing previous surface weathering effects. In order to characterise the intact strength of the rocks, we have undertaken unconfined compressive strength and triaxial strength tests using high pressure (400 kN maximum axial load; 64 MPa maximum cell pressure) triaxial testing apparatus. The results outline the peak strength characteristics of the unweathered materials. We then divided the samples of each lithology into different experimental groups. The first set of samples remained in the laboratory at constant temperature and humidity; this group provides our control. Samples from each of the three rock types were located at heights on the cliff face corresponding with the different lithologies: at the base (mudstone), in the mid cliff (shale) and at the top of the cliff (sandstone). This subjected them to the same conditions experienced by the in situ cliff

  16. Attenuation and Dispersion Analysis in Laboratory Measured Elastic Properties in the Middle East Carbonate Reservoir Rocks

    NASA Astrophysics Data System (ADS)

    Sharma, R.

    2016-12-01

    Carbonate rocks are sensitive to circulation of fluid types that leads to diagenetic alterations and therefore to heterogeneity in distribution of porosity and permeability. These heterogeneities in turn, lead to heterogeneity in saturations varying from partial to patchy to uniform. Depending on the interaction between fluids and rock matrix, a weakening or strengthening in shear modulus of carbonate rocks can also develop (Eberli et al., 2003; Adam et al., 2006; Sharma et al., 2009; Sharma et al., 2013). Thus the elastic response over the production life of the carbonate reservoirs can change considerably. Efforts to couple fluid flow with varying seismic properties of these reservoirs are limited in success due to the differences between static elastic properties derived from reservoir simulation and dynamic elastic properties derived from inverted seismic. An additional limitation arises from the assumption that shear modulus does not change with fluid type and saturations. To overcome these limitations, we need to understand the relationships between the static and the dynamic elastic properties using laboratory measurements made at varying pressures, frequencies and with varying saturants. I will present the following results: 1) errors associated with using dynamic (2 - 2000 Hz and 1 MHz) elastic properties data for static ( 0 Hz) reservoir properties, 2) shear modulus variation in carbonates upon saturation with varying saturants The results will enable us to estimate, 1) distribution of stress-strain relations in reservoir rocks and 2) modulus dispersion to correct seismic-derived moduli as inputs for reservoir simulators. The results are critical to estimate, 1) modulus dispersion correction and 2) occurrence and amount of shear modulus variation with fluid change vital for rock stability analysis

  17. RKR Franck-Condon factors for blue and ultraviolet transitions of some molecules of astrophysical interest and some comments on the interstellar abundance of CH, CH+ and SiH+.

    NASA Technical Reports Server (NTRS)

    Liszt, H. S.; Hayden Smith, W.

    1972-01-01

    RKR Franck-Condon factors for thirteen of the blue and ultraviolet transitions of AlF, AlO, BH, BD, CH, CD, CH(+), SiO and SiH(+) have been calculated. The interstellar abundances of CH, CH(+) and SiH(+) are discussed with regard to recent laboratory measurements, our Franck-Condon factors, and observations of the sun and the interstellar medium.

  18. Experimentally determined rock-fluid interactions applicable to a natural hot dry rock geothermal system

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Charles, R.W.; Holley, C.E. Jr.; Tester, J.W.

    1980-02-01

    The Los Alamos Scientific Laboratory is pursuing laboratory and field experiments in the development of the Hot Dry Rock concept of geothermal energy. The field program consists of experiments in a hydraulically fractured region of low permeability in which hot rock is intercepted by two wellbores. These experiments are designed to test reservoir engineering parameters such as: heat extraction rates, water loss rates, flow characteristics including impedance and buoyancy, seismic activity and fluid chemistry. Laboratory experiments have been designed to provide information on the mineral reactivity which may be encountered in the field program. Two experimental circulation systems have beenmore » built to study the rates of dissolution and alteration in dynamic flow. Solubility studies have been done in agitated systems. To date, pure minerals, samples of the granodiorite from the actual reservoir and Tijeras Canyon granite have been reacted with distilled water and various solutions of NaCl, NaOH, and Na/sub 2/CO/sub 3/. The results of these experimental systems are compared to observations made in field experiments done in a hot dry rock reservoir at a depth of approximately 3 km with initial rock temperatures of 150 to 200/sup 0/C.« less

  19. Field Verification Program (Aquatic Disposal): Comparison of Field and Laboratory Bioaccumulation of Organic and Inorganic Contaminants from Black Rock Harbor Dredged Material

    DTIC Science & Technology

    1988-05-01

    include poly- chlorinated biphenyls (PCBs) and related chlorinated pesticides of similar polarity in addition to the petroleum hydrocarbons . The...Ui It tILL (JV: FIELD VERIFICATION PROGRAM (AQUATIC DISPOSAL).’Wh TECHNICAL REPORT D-87-6 COMPARISON OF FIELD AND LABORATORY BIOACCUMULATION OF...Laboratory Bioaccumulation of Organic and Inorganic Contaminants from Black Rock Harbor Dredged Material 12 PERSONAL AUTHOR(S) Lake, James L.; Galloway

  20. Fundamental Research on Percussion Drilling: Improved rock mechanics analysis, advanced simulation technology, and full-scale laboratory investigations

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Michael S. Bruno

    This report summarizes the research efforts on the DOE supported research project Percussion Drilling (DE-FC26-03NT41999), which is to significantly advance the fundamental understandings of the physical mechanisms involved in combined percussion and rotary drilling, and thereby facilitate more efficient and lower cost drilling and exploration of hard-rock reservoirs. The project has been divided into multiple tasks: literature reviews, analytical and numerical modeling, full scale laboratory testing and model validation, and final report delivery. Literature reviews document the history, pros and cons, and rock failure physics of percussion drilling in oil and gas industries. Based on the current understandings, a conceptualmore » drilling model is proposed for modeling efforts. Both analytical and numerical approaches are deployed to investigate drilling processes such as drillbit penetration with compression, rotation and percussion, rock response with stress propagation, damage accumulation and failure, and debris transportation inside the annulus after disintegrated from rock. For rock mechanics modeling, a dynamic numerical tool has been developed to describe rock damage and failure, including rock crushing by compressive bit load, rock fracturing by both shearing and tensile forces, and rock weakening by repetitive compression-tension loading. Besides multiple failure criteria, the tool also includes a damping algorithm to dissipate oscillation energy and a fatigue/damage algorithm to update rock properties during each impact. From the model, Rate of Penetration (ROP) and rock failure history can be estimated. For cuttings transport in annulus, a 3D numerical particle flowing model has been developed with aid of analytical approaches. The tool can simulate cuttings movement at particle scale under laminar or turbulent fluid flow conditions and evaluate the efficiency of cutting removal. To calibrate the modeling efforts, a series of full-scale fluid hammer

  1. CH-TRU Waste Content Codes

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Washington TRU Solutions LLC

    2008-01-16

    The CH-TRU Waste Content Codes (CH-TRUCON) document describes the inventory of the U.S. Department of Energy (DOE) CH-TRU waste within the transportation parameters specified by the Contact-Handled Transuranic Waste Authorized Methods for Payload Control (CH-TRAMPAC). The CH-TRAMPAC defines the allowable payload for the Transuranic Package Transporter-II (TRUPACT-II) and HalfPACT packagings. This document is a catalog of TRUPACT-II and HalfPACT authorized contents and a description of the methods utilized to demonstrate compliance with the CH-TRAMPAC. A summary of currently approved content codes by site is presented in Table 1. The CH-TRAMPAC describes "shipping categories" that are assigned to each payload container.more » Multiple shipping categories may be assigned to a single content code. A summary of approved content codes and corresponding shipping categories is provided in Table 2, which consists of Tables 2A, 2B, and 2C. Table 2A provides a summary of approved content codes and corresponding shipping categories for the "General Case," which reflects the assumption of a 60-day shipping period as described in the CH-TRAMPAC and Appendix 3.4 of the CH-TRU Payload Appendices. For shipments to be completed within an approximately 1,000-mile radius, a shorter shipping period of 20 days is applicable as described in the CH-TRAMPAC and Appendix 3.5 of the CH-TRU Payload Appendices. For shipments to WIPP from Los Alamos National Laboratory (LANL), Nevada Test Site, and Rocky Flats Environmental Technology Site, a 20-day shipping period is applicable. Table 2B provides a summary of approved content codes and corresponding shipping categories for "Close-Proximity Shipments" (20-day shipping period). For shipments implementing the controls specified in the CH-TRAMPAC and Appendix 3.6 of the CH-TRU Payload Appendices, a 10-day shipping period is applicable. Table 2C provides a summary of approved content codes and corresponding shipping categories for "Controlled

  2. Evaluation of laboratory-scale in situ capping sediments with purple parent rock to control the eutrophication.

    PubMed

    Huang, Xuejiao; Shi, Wenhao; Ni, Jiupai; Li, Zhenlun

    2017-03-01

    In this study, the effectiveness of controlling the eutrophication using purple parent rock to cap the sediments was evaluated in the laboratory scale. Sediments were collected from Sanxikou reservoir (China) in July 2013. Then, three types of purple parent rock (T 1 f, J 3 p, and J 2 s) which are distributed widely in southwest China were used to cap the sediments. Limestone and calcite were used as the contrast group, because they had been reported as effective controls on eutrophication. Then, they were incubated at 20 °C for 46 days. The results indicated that the application of purple parent rock as a barrier material can effectively inhibit the release of nutrient elements in sediments, and the inhibition rates of total nitrogen (TN), total phosphorus (TP), ammonium (NH 4 -N), and nitrate (NO 3 -N) were much better than that of limestone and calcite. Among the three types of purple parent rock, J 3 p exhibited the best inhibitory effect on the release of nitrogen in sediments, and the inhibition efficiency of TN, NH 4 -N, and NO 3 -N was 59.7, 77.6, and 45.1%, respectively. As for T 1 f, it exhibited the best inhibitory effect on the release of TP in sediments with the inhibition rate of 94.4%. Whereas all these capping materials showed weak inhibition on release of organic matter in sediments, and the inhibition efficiencies were less than 20%. Moreover, these treatments could also cause distinct changes in the microbial community in sediments and overlying water, and the contents of TN and TP in all capping materials increased. All results demonstrated that purple parent rock could inhibit the release of nutrient in sediments through mechanical interception, physical adsorption, and chemical absorption as well as changing the microbial activity in the covering layer, sediments, or overlying water.

  3. Comprehensive Interpretation of the Laboratory Experiments Results to Construct Model of the Polish Shale Gas Rocks

    NASA Astrophysics Data System (ADS)

    Jarzyna, Jadwiga A.; Krakowska, Paulina I.; Puskarczyk, Edyta; Wawrzyniak-Guz, Kamila; Zych, Marcin

    2018-03-01

    More than 70 rock samples from so-called sweet spots, i.e. the Ordovician Sa Formation and Silurian Ja Member of Pa Formation from the Baltic Basin (North Poland) were examined in the laboratory to determine bulk and grain density, total and effective/dynamic porosity, absolute permeability, pore diameters size, total surface area, and natural radioactivity. Results of the pyrolysis, i.e., TOC (Total Organic Carbon) together with S1 and S2 - parameters used to determine the hydrocarbon generation potential of rocks, were also considered. Elemental composition from chemical analyses and mineral composition from XRD measurements were also included. SCAL analysis, NMR experiments, Pressure Decay Permeability measurements together with water immersion porosimetry and adsorption/ desorption of nitrogen vapors method were carried out along with the comprehensive interpretation of the outcomes. Simple and multiple linear statistical regressions were used to recognize mutual relationships between parameters. Observed correlations and in some cases big dispersion of data and discrepancies in the property values obtained from different methods were the basis for building shale gas rock model for well logging interpretation. The model was verified by the result of the Monte Carlo modelling of spectral neutron-gamma log response in comparison with GEM log results.

  4. Changes in Ultrasonic Velocity from Fluid Substitution, Calculated with Laboratory Methods, Digital Rock Physics, and Biot Theory

    NASA Astrophysics Data System (ADS)

    Goldfarb, E. J.; Ikeda, K.; Tisato, N.

    2017-12-01

    Seismic and ultrasonic velocities of rocks are function of several variables including fluid saturation and type. Understanding the effect of each variable on elastic waves can be valuable when using seismic methods for subsurface modeling. Fluid type and saturation are of specific interest to volcanology, water, and hydrocarbon exploration. Laboratory testing is often employed to understand the effects of fluids on elastic waves. However, laboratory testing is expensive and time consuming. It normally requires cutting rare samples into regular shapes. Fluid injection can also destroy specimens as removing the fluid after testing can prove difficult. Another option is theoretical modeling, which can be used to predict the effect of fluids on elastic properties, but it is often inaccurate. Alternatively, digital rock physics (DRP) can be used to investigate the effect of fluid substitution. DRP has the benefit of being non invasive, as it does not require regular sample shapes or fluid injection. Here, we compare the three methods for dry and saturated Berea sandstone to test the reliability of DRP. First, ultrasonic velocities were obtained from laboratory testing. Second, for comparison, we used a purely theoretical approach - i.e., Hashin-Shtrikman and Biot theory - to estimate the wave speeds at dry and wet conditions. Third, we used DRP. The dry sample was scanned with micro Computed Tomography (µCT), and a three dimensional (3D) array was recorded. We employed a segmentation-less method to convert each 3D array value to density, porosity, elastic moduli, and wave speeds. Wave propagation was simulated numerically at similar frequency as the laboratory. To simulate fluid substitution, we numerically substituted air values for water and repeated the simulation. The results from DRP yielded similar velocities to the laboratory, and accurately predicted the velocity change from fluid substitution. Theoretical modeling could not accurately predict velocity, and

  5. Analytical performance of a versatile laboratory microscopic X-ray fluorescence system for metal uptake studies on argillaceous rocks

    NASA Astrophysics Data System (ADS)

    Gergely, Felicián; Osán, János; Szabó, B. Katalin; Török, Szabina

    2016-02-01

    Laboratory-scale microscopic X-ray fluorescence (micro-XRF) plays an increasingly important role in various fields where multielemental investigations of samples are indispensable. In case of geological samples, the reasonable detection limits (LOD) and spatial resolutions are necessary to identify the trace element content in microcrystalline level. The present study focuses on the analytical performance of a versatile laboratory-scale micro-XRF system with various options of X-ray sources and detectors to find the optimal experimental configuration in terms of sensitivities and LOD for selected elements in loaded petrographic thin sections. The method was tested for sorption studies involving thin sections prepared from cores of Boda Claystone Formation, which is a potential site for a high-level radioactive waste repository. Loaded ions in the sorption measurements were Cs(I) and Ni(II) chemically representing fission and corrosion products. Based on the collected elemental maps, the correlation between the elements representative of main rock components and the selected loaded ion was studied. For the elements of interest, Cs(I) and Ni(II) low-power iMOXS source with polycapillary and silicon drift detector was found to be the best configuration to reach the optimal LOD values. Laboratory micro-XRF was excellent to identify the responsible key minerals for the uptake of Cs(I). In case of nickel, careful corrections were needed because of the relatively high Ca content of the rock samples. The results were compared to synchrotron radiation micro-XRF.

  6. Acceleration to failure in geophysical signals prior to laboratory rock failure and volcanic eruptions (Invited)

    NASA Astrophysics Data System (ADS)

    Main, I. G.; Bell, A. F.; Greenhough, J.; Heap, M. J.; Meredith, P. G.

    2010-12-01

    The nucleation processes that ultimately lead to earthquakes, volcanic eruptions, rock bursts in mines, and landslides from cliff slopes are likely to be controlled at some scale by brittle failure of the Earth’s crust. In laboratory brittle deformation experiments geophysical signals commonly exhibit an accelerating trend prior to dynamic failure. Similar signals have been observed prior to volcanic eruptions, including volcano-tectonic earthquake event and moment release rates. Despite a large amount of effort in the search, no such statistically robust systematic trend is found prior to natural earthquakes. Here we describe the results of a suite of laboratory tests on Mount Etna Basalt and other rocks to examine the nature of the non-linear scaling from laboratory to field conditions, notably using laboratory ‘creep’ tests to reduce the boundary strain rate to conditions more similar to those in the field. Seismic event rate, seismic moment release rate and rate of porosity change show a classic ‘bathtub’ graph that can be derived from a simple damage model based on separate transient and accelerating sub-critical crack growth mechanisms, resulting from separate processes of negative and positive feedback in the population dynamics. The signals exhibit clear precursors based on formal statistical model tests using maximum likelihood techniques with Poisson errors. After correcting for the finite loading time of the signal, the results show a transient creep rate that decays as a classic Omori law for earthquake aftershocks, and remarkably with an exponent near unity, as commonly observed for natural earthquake sequences. The accelerating trend follows an inverse power law when fitted in retrospect, i.e. with prior knowledge of the failure time. In contrast the strain measured on the sample boundary shows a less obvious but still accelerating signal that is often absent altogether in natural strain data prior to volcanic eruptions. To test the

  7. Weathering of rock 'Ginger'

    NASA Technical Reports Server (NTRS)

    1997-01-01

    One of the more unusual rocks at the site is Ginger, located southeast of the lander. Parts of it have the reddest color of any material in view, whereas its rounded lobes are gray and relatively unweathered. These color differences are brought out in the inset, enhanced at the upper right. In the false color image at the lower right, the shape of the visible-wavelength spectrum (related to the abundance of weathered ferric iron minerals) is indicated by the hue of the rocks. Blue indicates relatively unweathered rocks. Typical soils and drift, which are heavily weathered, are shown in green and flesh tones. The very red color in the creases in the rock surface correspond to a crust of ferric minerals. The origin of the rock is uncertain; the ferric crust may have grown underneath the rock, or it may cement pebbles together into a conglomerate. Ginger will be a target of future super-resolution studies to better constrain its origin.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator. JPL is an operating division of the California Institute of Technology (Caltech).

  8. Rock Garden Mosaic

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This image mosaic of part of the 'Rock Garden' was taken by the Sojourner rover's left front camera on Sol 71 (September 14). The rock 'Shark' is at left center and 'Half Dome' is at right. Fine-scale textures on the rocks are clearly seen. Broken crust-like material is visible at bottom center.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

  9. Zapping Rocks on Mars

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wiens, Roger

    Better understanding Mars means better understanding its geology. That’s why, sitting atop NASA’s Curiosity rover, is ChemCam, an instrument built by Los Alamos National Laboratory that shoots lasers at Martian rocks and analyzes the data. After nearly 1,500 rock zaps, ChemCam has uncovered some surprising facts about the Red Planet, including the discovery of igneous rocks. Soon, a new Los Alamos-built instrument—the SuperCam—will ride aboard the Mars 2020 rover and bring with it enhanced capabilities to unlock new secrets about the planet.

  10. A Novel Mobile Testing Equipment for Rock Cuttability Assessment: Vertical Rock Cutting Rig (VRCR)

    NASA Astrophysics Data System (ADS)

    Yasar, Serdar; Yilmaz, Ali Osman

    2017-04-01

    In this study, a new mobile rock cutting testing apparatus was designed and produced for rock cuttability assessment called vertical rock cutting rig (VRCR) which was designed specially to fit into hydraulic press testing equipment which are available in almost every rock mechanics laboratory. Rock cutting trials were initiated just after the production of VRCR along with calibration of the measuring load cell with an external load cell to validate the recorded force data. Then, controlled rock cutting tests with both relieved and unrelieved cutting modes were implemented on five different volcanic rock samples with a standard simple-shaped wedge tool. Additionally, core cutting test which is an important approach for roadheader performance prediction was simulated with VRCR. Mini disc cutters and point attack tools were used for execution of experimental trials. Results clearly showed that rock cutting tests were successfully realized and measuring system is delicate to rock strength, cutting depth and other variables. Core cutting test was successfully simulated, and it was also shown that rock cutting tests with mini disc cutters and point attack tools are also successful with VRCR.

  11. G331.512–0.103: An Interstellar Laboratory for Molecular Synthesis. I. The Ortho-to-para Ratios for CH3OH and CH3CN

    NASA Astrophysics Data System (ADS)

    Mendoza, Edgar; Bronfman, Leonardo; Duronea, Nicolas U.; Lépine, Jacques R. D.; Finger, Ricardo; Merello, Manuel; Hervías-Caimapo, Carlos; Gama, Diana R. G.; Reyes, Nicolas; Åke-Nyman, Lars

    2018-02-01

    Spectral line surveys reveal rich molecular reservoirs in G331.512–0.103, a compact radio source in the center of an energetic molecular outflow. In this first work, we analyze the physical conditions of the source by means of CH3OH and CH3CN. The observations were performed with the APEX Telescope. Six different system configurations were defined to cover most of the band within (292–356) GHz as a consequence, we detected a forest of lines toward the central core. A total of 70 lines of A/E–CH3OH and A/E–CH3CN were analyzed, including torsionally excited transitions of CH3OH ({ν }t=1). In a search for all the isotopologues, we identified transitions of 13CH3OH. The physical conditions were derived considering collisional and radiative processes. We found common temperatures for each A and E symmetry of CH3OH and CH3CN; the derived column densities indicate an A/E equilibrated ratio for both tracers. The results reveal that CH3CN and CH3OH trace a hot and cold component with {T}k∼ 141 K and {T}k∼ 74 K, respectively. In agreement with previous ALMA observations, the models show that the emission region is compact (≲ 5\\buildrel{\\prime\\prime}\\over{.} 5) with gas density n(H2) = (0.7–1)×107 cm‑3. The CH3OH/CH3CN abundance ratio and the evidences for prebiotic and complex organic molecules suggest a rich and active chemistry toward G331.512–0.103.

  12. High-Silica Lamoose Rock

    NASA Image and Video Library

    2015-07-23

    A rock fragment dubbed "Lamoose" is shown in this picture taken by the Mars Hand Lens Imager (MAHLI) on NASA's Curiosity rover. Like other nearby rocks in a portion of the "Marias Pass" area of Mt. Sharp, Mars, it has unusually high concentrations of silica. The high silica was first detected in the area by the Chemistry & Camera (ChemCam) laser spectrometer. This rock was targeted for follow-up study by the MAHLI and the arm-mounted Alpha Particle X-ray Spectrometer (APXS). Silica is a rock-forming compound containing silicon and oxygen, commonly found on Earth as quartz. High levels of silica could indicate ideal conditions for preserving ancient organic material, if present, so the science team wants to take a closer look. The rock is about 4 inches (10 centimeters) across. It is fine-grained, perhaps finely layered, and etched by the wind. The image was taken on the 1,041st Martian day, or sol, of the mission (July 11, 2015). MAHLI was built by Malin Space Science Systems, San Diego. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Science Laboratory Project for the NASA Science Mission Directorate, Washington. JPL designed and built the project's Curiosity rover. http://photojournal.jpl.nasa.gov/catalog/PIA19828

  13. On the physical properties of volcanic rock masses

    NASA Astrophysics Data System (ADS)

    Heap, M. J.; Villeneuve, M.; Ball, J. L.; Got, J. L.

    2017-12-01

    The physical properties (e.g., elastic properties, porosity, permeability, cohesion, strength, amongst others) of volcanic rocks are crucial input parameters for modelling volcanic processes. These parameters, however, are often poorly constrained and there is an apparent disconnect between modellers and those who measure/determine rock and rock mass properties. Although it is well known that laboratory measurements are scale dependent, experimentalists, field volcanologists, and modellers should work together to provide the most appropriate model input parameters. Our pluridisciplinary approach consists of (1) discussing with modellers to better understand their needs, (2) using experimental know-how to build an extensive database of volcanic rock properties, and (3) using geotechnical and field-based volcanological know-how to address scaling issues. For instance, increasing the lengthscale of interest from the laboratory-scale to the volcano-scale will reduce the elastic modulus and strength and increase permeability, but to what extent? How variable are the physical properties of volcanic rocks, and is it appropriate to assume constant, isotropic, and/or homogeneous values for volcanoes? How do alteration, depth, and temperature influence rock physical and mechanical properties? Is rock type important, or do rock properties such as porosity exert a greater control on such parameters? How do we upscale these laboratory-measured properties to rock mass properties using the "fracturedness" of a volcano or volcanic outcrop, and how do we quantify fracturedness? We hope to discuss and, where possible, address some of these issues through active discussion between two (or more) scientific communities.

  14. Estimation of Confined Peak Strength of Crack-Damaged Rocks

    NASA Astrophysics Data System (ADS)

    Bahrani, Navid; Kaiser, Peter K.

    2017-02-01

    It is known that the unconfined compressive strength of rock decreases with increasing density of geological features such as micro-cracks, fractures, and veins both at the laboratory specimen and rock block scales. This article deals with the confined peak strength of laboratory-scale rock specimens containing grain-scale strength dominating features such as micro-cracks. A grain-based distinct element model, whereby the rock is simulated with grains that are allowed to deform and break, is used to investigate the influence of the density of cracks on the rock strength under unconfined and confined conditions. A grain-based specimen calibrated to the unconfined and confined strengths of intact and heat-treated Wombeyan marble is used to simulate rock specimens with varying crack densities. It is demonstrated how such cracks affect the peak strength, stress-strain curve and failure mode with increasing confinement. The results of numerical simulations in terms of unconfined and confined peak strengths are used to develop semi-empirical relations that relate the difference in strength between the intact and crack-damaged rocks to the confining pressure. It is shown how these relations can be used to estimate the confined peak strength of a rock with micro-cracks when the unconfined and confined strengths of the intact rock and the unconfined strength of the crack-damaged rock are known. This approach for estimating the confined strength of crack-damaged rock specimens, called strength degradation approach, is then verified by application to published laboratory triaxial test data.

  15. Rock Types in Gale Crater

    NASA Image and Video Library

    2011-07-22

    This oblique view of the mound in Gale crater shows several different rock types of interest to the Mars Science Laboratory mission. The Mars Science Laboratory rover, Curiosity, will use its full instrument suite to study these minerals and how they form

  16. Laboratory experiments of crater formation on ice-rock mixture targets

    NASA Astrophysics Data System (ADS)

    Hiraoka, K.; Arakawa, M.; Yoshikawa, K.; Nakamura, A. M.

    Surfaces of ice-rock mixture are common among planetary bodies in outer solar system, such as the satellites of the giant planets, comet nuclei, and so on. In order to study the effect of the presence of volatiles in crater formation on these bodies, we performed impact experiments using a two-stage light-gas gun and a gas gun at Hokkaido University. The targets were ice-rock mixtures (diameter = 10 or 30cm, height = 5cm) with 0 wt.% to 50 wt.% rock. Projectiles were ice cylinders (diameter = 15mm, height = 10mm) or corn-shaped nylon ones and the impact velocities were varied from about 300m/s to 3500m/s. We will show an anti-correlation between the crater volume and the rock content, and will make a comparison with previous works (Lange and Ahrens 1982; Koschny and Grun 2001). Ejecta size and velocity measured on high-speed video images will be presented and will be discussed by a comparison with a spallation model (Melosh 1984).

  17. Transport and attenuation of carboxylate-modified latex microspheres in fractured rock laboratory and field tracer tests

    USGS Publications Warehouse

    Becker, M.W.; Reimus, P.W.; Vilks, P.

    1999-01-01

    Understanding colloid transport in ground water is essential to assessing the migration of colloid-size contaminants, the facilitation of dissolved contaminant transport by colloids, in situ bioremediation, and the health risks of pathogen contamination in drinking water wells. Much has been learned through laboratory and field-scale colloid tracer tests, but progress has been hampered by a lack of consistent tracer testing methodology at different scales and fluid velocities. This paper presents laboratory and field tracer tests in fractured rock that use the same type of colloid tracer over an almost three orders-of-magnitude range in scale and fluid velocity. Fluorescently-dyed carboxylate-modified latex (CML) microspheres (0.19 to 0.98 ??m diameter) were used as tracers in (1) a naturally fractured tuff sample, (2) a large block of naturally fractured granite, (3) a fractured granite field site, and (4) another fractured granite/schist field site. In all cases, the mean transport time of the microspheres was shorter than the solutes, regardless of detection limit. In all but the smallest scale test, only a fraction of the injected microsphere mass was recovered, with the smaller microspheres being recovered to a greater extent than the larger microspheres. Using existing theory, we hypothesize that the observed microsphere early arrival was due to volume exclusion and attenuation was due to aggregation and/or settling during transport. In most tests, microspheres were detected using flow cytometry, which proved to be an excellent method of analysis. CML microspheres appear to be useful tracers for fractured rock in forced gradient and short-term natural gradient tests, but longer residence times may result in small microsphere recoveries.Understanding colloid transport in ground water is essential to assessing the migration of colloid-size contaminants, the facilitation of dissolved contaminant transport by colloids, in situ bioremediation, and the health risks

  18. Zapping Rocks on Mars

    ScienceCinema

    Wiens, Roger

    2018-01-16

    Better understanding Mars means better understanding its geology. That’s why, sitting atop NASA’s Curiosity rover, is ChemCam, an instrument built by Los Alamos National Laboratory that shoots lasers at Martian rocks and analyzes the data. After nearly 1,500 rock zaps, ChemCam has uncovered some surprising facts about the Red Planet, including the discovery of igneous rocks. Soon, a new Los Alamos-built instrument—the SuperCam—will ride aboard the Mars 2020 rover and bring with it enhanced capabilities to unlock new secrets about the planet.

  19. The Vaigat Rock Avalanche Laboratory, west-central Greenland

    NASA Astrophysics Data System (ADS)

    Dunning, S.; Rosser, N. J.; Szczucinski, W.; Norman, E. C.; Benjamin, J.; Strzelecki, M.; Long, A. J.; Drewniak, M.

    2013-12-01

    Rock avalanches have unusually high mobility and pose both an immediate hazard, but also produce far-field impacts associated with dam breach, glacier collapse and where they run-out into water, tsunami. Such secondary hazards can often pose higher risks than the original landslide. The prediction of future threats posed by potential rock avalanches is heavily reliant upon understanding of the physics derived from an interpretation of deposits left by previous events, yet drawing comparisons between multiple events is normally challenging as interactions with complex mountainous terrain makes deposits from each event unique. As such numerical models and the interpretation of the underlying physics which govern landslide mobility is commonly case-specific and poorly suited to extrapolation beyond the single events the model is tuned to. Here we present a high-resolution LiDAR and hyperspectral dataset captured across a unique cluster of large rock avalanche source areas and deposits in the Vaigat straight, west central Greenland. Vaigat offers the unprecedented opportunity to model a sample of > 15 rock avalanches of various age sourced from an 80 km coastal escarpment. At Vaigat many of the key variables (topography, geology, post-glacial history) are held constant across all landslides providing the chance to investigate the variations in dynamics and emplacement style related to variable landslide volume, drop-heights, and thinning/spreading over relatively simple, unrestricted run-out zones both onto land and into water. Our data suggest that this region represents excellent preservation of landslide deposits, and hence is well suited to calibrate numerical models of run out dynamics. We use this data to aid the interpretation of deposit morphology, structure lithology and run-out characteristics in more complex settings. Uniquely, we are also able to calibrate our models using a far-field dataset of well-preserved tsunami run-up deposits, resulting from the 21

  20. Sojourner near the Rock Garden

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This image of the Sojourner rover was taken near the end of daytime operations on Sol 42. The rover is between the rocks 'Wedge' (left) and 'Flute Top' (right). Other rocks visible include 'Flat Top' (behind Flute Top) and those in the Rock Garden, at the top of the frame. The cylindrical object extending from the back end of Sojourner is the Alpha Proton X-Ray Spectrometer.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

  1. Spectral variations in rocks and soils containing ferric iron hydroxide and(or) sulfate minerals as seen by AVIRIS and laboratory spectroscopy

    USGS Publications Warehouse

    Rockwell, Barnaby W.

    2004-01-01

    Analysis of Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) data covering the Big Rock Candy Mountain area of the Marysvale volcanic field, west-central Utah, identified abundant rocks and soils bearing jarosite, goethite, and chlorite associated with volcanic rocks altered to propylitic grade during the Miocene (2321 Ma). Propylitically-altered rocks rich in pyrite associated with the relict feeder zones of convecting, shallow hydrothermal systems are currently undergoing supergene oxidation to natrojarosite, kaolinite, and gypsum. Goethite coatings are forming at the expense of jarosite where most pyrite has been consumed through oxidation in alluvium derived from pyrite-bearing zones. Spectral variations in the goethite-bearing rocks that resemble variations found in reference library samples of goethites of varying grain size were observed in the AVIRIS data. Rocks outside of the feeder zones have relatively low pyrite content and are characterized by chlorite, epidote, and calcite, with local copper-bearing quartz-calcite veins. Iron-bearing minerals in these rocks are weathering directly to goethite. Laboratory spectral analyses were applied to samples of iron-bearing rock outcrops and alluvium collected from the area to determine the accuracy of the AVIRIS-based mineral identification. The accuracy of the iron mineral identification results obtained by analysis of the AVIRIS data was confirmed. In general, the AVIRIS analysis results were accurate in identifying medium-grained goethite, coarse-grained goethite, medium- to coarse-grained goethite with trace jarosite, and mixtures of goethite and jarosite. However, rock fragments from alluvial areas identified as thin coatings of goethite with the AVIRIS data were found to consist mainly of medium- to coarse-grained goethite based on spectral characteristics in the visible and near-infrared. To determine if goethite abundance contributed to the spectral variations observed in goethite-bearing rocks

  2. Real-time noble gas release signaling rock deformation

    NASA Astrophysics Data System (ADS)

    Bauer, S. J.; Gardner, W. P.; Lee, H.

    2016-12-01

    We present empirical results/relationships of rock strain, microfracture density, acoustic emissions, and noble gas release from laboratory triaxial experiments for a granite and basalt. Noble gases are contained in most crustal rock at inter/intra granular sites, their release during natural and manmade stress and strain changes represents a signal of brittle/semi brittle deformation. The gas composition depends on lithology, geologic history and age, fluids present, and uranium, thorium and potassium-40 concentrations in the rocks that affect radiogenic noble gases (helium, argon) production. Noble gas emission and its relationship to crustal processes have been studied, including correlations to tectonic velocities and qualitative estimates of deep permeability from surface measurements, finger prints of nuclear weapon detonation, and as potential precursory signals to earthquakes attributed to gas release due to pre-seismic stress, dilatancy and/or rock fracturing. Helium emission has been shown as a precursor of volcanic activity. Real-time noble gas release is observed using an experimental system utilizing mass spectrometers to measure gases released during triaxial rock deformation. Noble gas release is shown to represent a sensitive precursor signal of rock deformation by relating real-time noble gas release to stress-strain state changes and acoustic emissions. We propose using noble gas release to also signal rock deformation in boreholes, mines and nuclear waste repositories. We postulate each rock exhibits a gas release signature which is microstructure, stress/strain state, and or permanent deformation dependent. Such relationships, when calibrated, may be used to sense rock deformation and then develop predictive models. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corp., for the US Dept. of Energy's National Nuclear Security Administration under

  3. Rock shape, restitution coefficients and rockfall trajectory modelling

    NASA Astrophysics Data System (ADS)

    Glover, James; Christen, Marc; Bühler, Yves; Bartelt, Perry

    2014-05-01

    Restitution coefficients are used in rockfall trajectory modelling to describe the ratio between incident and rebound velocities during ground impact. They are central to the problem of rockfall hazard analysis as they link rock mass characteristics to terrain properties. Using laboratory experiments as a guide, we first show that restitution coefficients exhibit a wide range of scatter, although the material properties of the rock and ground are constant. This leads us to the conclusion that restitution coefficients are poor descriptors of rock-ground interaction. The primary problem is that "apparent" restitution coefficients are applied at the rock's centre-of-mass and do not account for rock shape. An accurate description of the rock-ground interaction requires the contact forces to be applied at the rock surface with consideration of the momentary rock position and spin. This leads to a variety of rock motions including bouncing, sliding, skipping and rolling. Depending on the impact configuration a wide range of motions is possible. This explains the large scatter of apparent restitution coefficients. We present a rockfall model based on newly developed hard-contact algorithms which includes the effects of rock shape and therefore is able to reproduce the results of different impact configurations. We simulate the laboratory experiments to show that it is possible to reproduce run-out and dispersion of different rock shapes using parameters obtained from independent tests. Although this is a step forward in rockfall trajectory modelling, the problem of parametersing real terrain remains.

  4. Analyses of rocks from the laboratory of the United States Geological Survey, 1880-1903

    USGS Publications Warehouse

    Clarke, F.W.

    1904-01-01

    The present Geological Survey of the United States was organized in 1879. In 1880 a chemical laboratory was established at Denver, in connection with the Colorado work, in charge of Dr. W. F. Hillebrand, with whom were associated Mr. Antony Guyard and, later, Mr. L. G. Eakins. In 1882 Dr. W. H. Melville was placed in charge of a second laboratory at San Francisco, and in the autumn of 1883 the central laboratory was started in Washington, with myself as chief chemist. In November, 1885, Doctor Hillebrand was transferred to Washington; early in 1888 he was followed by Mr. Eakins, and the Denver laboratory was discontinued. In the spring of 1890 Doctor Melville also was transferred to Washington, and since then the chemical work of the Survey has been concentrated at headquarters.Up to January 1, 1904, over 5,300 analyses have been made in the laboratory at Washington. These represent rocks, minerals, ores, waters, sediments, coals, metals, and so on through all the range of substances with which geology has to do. There were also some hundreds of analyses made in the laboratories at Denver and San Francisco. A fair amount of research work upon mineralogical and analytical problems has also been done. In all of this work the following chemists have been employed: E. T. Allen, Charles Catlett, T. M. Chatard, F. W. Clarke, L. G. Eakins, F. A. Gooch, Antony Guyard, W. F. Hillebrand, W. H. Melville, R. B. Riggs, W. T. Schaller, E. A. Schneider, George Steiger, H. N. Stokes, E. C. Sullivan, William Valentine, and J. E. Whitfield. As many as eight of these have been at work simultaneously; at present only six are connected with the Survey. Other officers of the Survey have been occupied more or less with chemical questions; but the men named in this list were connected directly with the laboratory. Some work for the chemical division has also been done by chemists not regularly on the rolls of the Survey; but their analyses, with the exception of a single group to be

  5. Digital material laboratory: Considerations on high-porous volcanic rock

    NASA Astrophysics Data System (ADS)

    Saenger, Erik H.; Stöckhert, Ferdinand; Duda, Mandy; Fischer, Laura; Osorno, Maria; Steeb, Holger

    2017-04-01

    Digital material methodology combines modern microscopic imaging with advanced numerical simulations of the physical properties of materials. One goal is to complement physical laboratory investigations for a deeper understanding of relevant physical processes. Large-scale numerical modeling of elastic wave propagation directly from the microstructure of the porous material is integral to this technology. The parallelized finite-difference-based Stokes solver is suitable for the calculation of effective hydraulic parameters for low and high porous materials. Reticulite is formed in very high Hawaiian fire fountaining events. Hawaiian fire fountaining eruptions produce columns or fountains of lava, which can last for a few hours to days. Reticulite was originally thought to have formed from further expanded hot scoria foam. However, some researchers believe reticulite forms from magma that formed vesicles instantly, which expanded rapidly and uniformly to produce the polyhedral vesicle walls. These walls then ruptured and cooled rapidly. The (open) honeycomb network of bubbles is held together by glassy threads and forms a structure with a porosity higher than 80%. The fragile rock sample is difficult to characterize with classical experimental methods and we show how to determine porosity, effective elastic properties and Darcy permeability by using digital material methodology. A technical challenge will be to image with the CT technique the thin skin between the glassy threads visible on the microscopy image. A numerical challenge will be determination of effective material properties and viscous fluid effects on wave propagation in such a high porous material.

  6. Segmentation-less Digital Rock Physics

    NASA Astrophysics Data System (ADS)

    Tisato, N.; Ikeda, K.; Goldfarb, E. J.; Spikes, K. T.

    2017-12-01

    In the last decade, Digital Rock Physics (DRP) has become an avenue to investigate physical and mechanical properties of geomaterials. DRP offers the advantage of simulating laboratory experiments on numerical samples that are obtained from analytical methods. Potentially, DRP could allow sparing part of the time and resources that are allocated to perform complicated laboratory tests. Like classic laboratory tests, the goal of DRP is to estimate accurately physical properties of rocks like hydraulic permeability or elastic moduli. Nevertheless, the physical properties of samples imaged using micro-computed tomography (μCT) are estimated through segmentation of the μCT dataset. Segmentation proves to be a challenging and arbitrary procedure that typically leads to inaccurate estimates of physical properties. Here we present a novel technique to extract physical properties from a μCT dataset without the use of segmentation. We show examples in which we use segmentation-less method to simulate elastic wave propagation and pressure wave diffusion to estimate elastic properties and permeability, respectively. The proposed method takes advantage of effective medium theories and uses the density and the porosity that are measured in the laboratory to constrain the results. We discuss the results and highlight that segmentation-less DRP is more accurate than segmentation based DRP approaches and theoretical modeling for the studied rock. In conclusion, the segmentation-less approach here presented seems to be a promising method to improve accuracy and to ease the overall workflow of DRP.

  7. In Situ Observation of Rock Spalling in the Deep Tunnels of the China Jinping Underground Laboratory (2400 m Depth)

    NASA Astrophysics Data System (ADS)

    Feng, Xia-Ting; Xu, Hong; Qiu, Shi-Li; Li, Shao-Jun; Yang, Cheng-Xiang; Guo, Hao-Sen; Cheng, Yuan; Gao, Yao-Hui

    2018-04-01

    To study rock spalling in deep tunnels at China Jinping Underground Laboratory Phase II (CJPL-II), photogrammetry method and digital borehole camera were used to quantify key features of rock spalling including orientation, thickness of slabs and the depth of spalling. The failure mechanism was analysed through scanning electron microscope and numerical simulation based on FLAC3D. Observation results clearly showed the process of rock spalling failure: a typical spalling pattern around D-shaped tunnels after top-heading and bottom bench were discovered. The orientation and thickness of the slabs were obtained. The slabs were parallel to the excavated surfaces of the tunnel and were related to the shape of the tunnel surface and orientation of the principal stress. The slabs were alternately thick and thin, and they gradually increased in thickness from the sidewall inwards. The form and mechanism of spalling at different locations in the tunnels, as influenced by stress state and excavation, were analysed. The result of this study was helpful to those rethinking the engineering design, including the excavation and support of tunnels, or caverns, at high risk of spalling.

  8. Physical properties and rock physics models of sediment containing natural and laboratory-formed methane gas hydrate

    USGS Publications Warehouse

    Winters, W.J.; Pecher, I.A.; Waite, W.F.; Mason, D.H.

    2004-01-01

    This paper presents results of shear strength and acoustic velocity (p-wave) measurements performed on: (1) samples containing natural gas hydrate from the Mallik 2L-38 well, Mackenzie Delta, Northwest Territories; (2) reconstituted Ottawa sand samples containing methane gas hydrate formed in the laboratory; and (3) ice-bearing sands. These measurements show that hydrate increases shear strength and p-wave velocity in natural and reconstituted samples. The proportion of this increase depends on (1) the amount and distribution of hydrate present, (2) differences, in sediment properties, and (3) differences in test conditions. Stress-strain curves from the Mallik samples suggest that natural gas hydrate does not cement sediment grains. However, stress-strain curves from the Ottawa sand (containing laboratory-formed gas hydrate) do imply cementation is present. Acoustically, rock physics modeling shows that gas hydrate does not cement grains of natural Mackenzie Delta sediment. Natural gas hydrates are best modeled as part of the sediment frame. This finding is in contrast with direct observations and results of Ottawa sand containing laboratory-formed hydrate, which was found to cement grains (Waite et al. 2004). It therefore appears that the microscopic distribution of gas hydrates in sediment, and hence the effect of gas hydrate on sediment physical properties, differs between natural deposits and laboratory-formed samples. This difference may possibly be caused by the location of water molecules that are available to form hydrate. Models that use laboratory-derived properties to predict behavior of natural gas hydrate must account for these differences.

  9. Measurement of rock mass deformation with grouted coaxial antenna cables

    NASA Astrophysics Data System (ADS)

    Dowding, C. H.; Su, M. B.; O'Connor, K.

    1989-01-01

    Techniques presented herein show how reflected voltage pulses from coaxial antenna cable grouted in rock masses can be employed to quantify the type and magnitude of rock mass deformation. This measurement is similar to that obtained from a combined full profile extensometer (to measure local extension) and inclinometer (to measure local shearing). Rock mass movements deform the grouted cable, which locally changes cable capacitance and thereby the reflected wave form of the voltage pulse. Thus, by monitoring changes in these reflection signatures, it is possible to monitor rock mass deformation. This paper presents laboratory measurements necessary to quantitatively interpret the reflected voltage signatures. Cables were sheared and extended to correlate measured cable deformation with reflected voltage signals. Laboratory testing included development of grout mixtures with optimum properties for field installation and performance of a TDR (Time Domain Reflectometry) monitoring system. Finally, the interpretive techniques developed through laboratory measurements were applied to previously collected field data to extract hitherto unrealized information.

  10. Fault Damage Zone Permeability in Crystalline Rocks from Combined Field and Laboratory Measurements: Can we Predict Damage Zone Permeability?

    NASA Astrophysics Data System (ADS)

    Mitchell, T. M.; Faulkner, D. R.

    2009-04-01

    Models predicting crustal fluid flow are important for a variety of reasons; for example earthquake models invoking fluid triggering, predicting crustal strength modelling flow surrounding deep waste repositories or the recovery of natural resources. Crustal fluid flow is controlled by both the bulk transport properties of rocks as well as heterogeneities such as faults. In nature, permeability is enhanced in the damage zone of faults, where fracturing occurs on a wide range of scales. Here we analyze the contribution of microfracture damage on the permeability of faults that cut through low porosity, crystalline rocks by combining field and laboratory measurements. Microfracture densities surrounding strike-slip faults with well-constrained displacements ranging over 3 orders of magnitude (~0.12 m - 5000 m) have been analyzed. The faults studied are excellently exposed within the Atacama Fault Zone, where exhumation from 6-10 km has occurred. Microfractures in the form of fluid inclusion planes (FIPs) show a log-linear decrease in fracture density with perpendicular distance from the fault core. Damage zone widths defined by the density of FIPs scale with fault displacement, and an empirical relationship for microfracture density distribution throughout the damage zone with displacement is derived. Damage zone rocks will have experienced differential stresses that were less than, but some proportion of, the failure stress. As such, permeability data from progressively loaded, initially intact laboratory samples, in the pre-failure region provide useful insights into fluid flow properties of various parts of the damage zone. The permeability evolution of initially intact crystalline rocks under increasing differential load leading to macroscopic failure was determined at water pore pressures of 50 MPa and effective pressure of 10 MPa. Permeability is seen to increase by up to, and over, two orders of magnitude prior to macroscopic failure. Further experiments were

  11. Semantic modeling of plastic deformation of polycrystalline rock

    NASA Astrophysics Data System (ADS)

    Babaie, Hassan A.; Davarpanah, Armita

    2018-02-01

    We have developed the first iteration of the Plastic Rock Deformation (PRD) ontology by modeling the semantics of a selected set of deformational processes and mechanisms that produce, reconfigure, displace, and/or consume the material components of inhomogeneous polycrystalline rocks. The PRD knowledge model also classifies and formalizes the properties (relations) that hold between instances of the dynamic physical and chemical processes and the rock components, the complex physio-chemical, mathematical, and informational concepts of the plastic rock deformation system, the measured or calculated laboratory testing conditions, experimental procedures and protocols, the state and system variables, and the empirical flow laws that define the inter-relationships among the variables. The ontology reuses classes and properties from several existing ontologies that are built for physics, chemistry, biology, and mathematics. With its flexible design, the PRD ontology is well positioned to incrementally develop into a model that more fully represents the knowledge of plastic deformation of polycrystalline rocks in the future. The domain ontology will be used to consistently annotate varied data and information related to the microstructures and the physical and chemical processes that produce them at different spatial and temporal scales in the laboratory and in the solid Earth. The PRDKB knowledge base, when built based on the ontology, will help the community of experimental structural geologists and metamorphic petrologists to coherently and uniformly distribute, discover, access, share, and use their data through automated reasoning and integration and query of heterogeneous experimental deformation data that originate from autonomous rock testing laboratories.

  12. Study of gamma spectrometry laboratory measurement in various sediment and vulcanic rocks

    NASA Astrophysics Data System (ADS)

    Nurhandoko, Bagus Endar B.; Kurniadi, Rizal; Rizka Asmara Hadi, Muhammad; Rizal Komara, Insan

    2017-01-01

    Gamma-ray spectroscopy is the quantitative study of the energy spectra of gamma-ray sources. This method is powerful to characterize some minerals, especially to differentiate rocks which contains among Potassium, Uranium, dan Thorium. Rock contains radioactive material which produce gamma rays in various energies and intensities. When these emissions are detected and analyzed with a spectroscopy system, a gamma-ray energy spectrum can be used as indicator for mineral content of rock. Some sediment and vulcanic rock have been collected from East Java Basin. Samples are ranging from Andesite vulcanics, Tuff, Shale, various vulcanic clay and Alluvial clay. We present some unique characteristics of gamma spectrometry in various sedimentar and vulcanic rocks of East Java Basins. Details contents of gamma ray spectra give enrichments to characterize sample of sediment and vulcanic in East Java. Weathered vulcanic clay has lower counting rate of gamma ray than alluvial deltaic clay counting rate. Therefore, gamma spectrometrometry can be used as tool for characterizing the enviroment of clay whether vulcanic or alluvial-deltaic. This phenomena indicates that gamma ray spectrometry can be as tool for characterizing the clay whether it tends to Smectite or Illite

  13. Abiotic dechlorination in rock matrices impacted by long-term exposure to TCE.

    PubMed

    Schaefer, Charles E; Towne, Rachael M; Lippincott, David R; Lacombe, Pierre J; Bishop, Michael E; Dong, Hailiang

    2015-01-01

    Field and laboratory tests were performed to evaluate the abiotic reaction of trichloroethene (TCE) in sedimentary rock matrices. Hydraulically conductive fractures, and the rock directly adjacent to the hydraulically conductive fractures, within a historically contaminated TCE bedrock aquifer were used as the basis for this study. These results were compared to previous work using rock that had not been exposed to TCE (Schaefer et al., 2013) to assess the impact of long-term TCE exposure on the abiotic dechlorination reaction, as the longevity of these reactions after long-term exposure to TCE was hitherto unknown. Results showed that potential abiotic TCE degradation products, including ethane, ethene, and acetylene, were present in the conductive fractures. Using minimally disturbed slices of rock core at and near the fracture faces, laboratory testing on the rocks confirmed that abiotic dechlorination reactions between the rock matrix and TCE were occurring. Abiotic daughter products measured in the laboratory under controlled conditions were consistent with those measured in the conductive fractures, except that propane also was observed as a daughter product. TCE degradation measured in the laboratory was well described by a first order rate constant through the 118-d study. Observed bulk first-order TCE degradation rate constants within the rock matrix were 1.3×10(-8) s(-1). These results clearly show that abiotic dechlorination of TCE is occurring within the rock matrix, despite decades of exposure to TCE. Furthermore, these observed rates of TCE dechlorination are expected to have a substantial impact on TCE migration and uptake/release from rock matrices. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Cooperative investigation of precision and accuracy: In chemical analysis of silicate rocks

    USGS Publications Warehouse

    Schlecht, W.G.

    1951-01-01

    This is the preliminary report of the first extensive program ever organized to study the analysis of igneous rocks, a study sponsored by the United States Geological Survey, the Massachusetts Institute of Technology, and the Geophysical Laboratory of the Carnegie Institution of Washington. Large samples of two typical igneous rocks, a granite and a diabase, were carefully prepared and divided. Small samples (about 70 grams) of each were sent to 25 rock-analysis laboratories throughout the world; analyses of one or both samples were reported by 34 analysts in these laboratories. The results, which showed rather large discrepancies, are presented in histograms. The great discordance in results reflects the present unsatisfactory state of rock analysis. It is hoped that the ultimate establishment of standard samples and procedures will contribute to the improvement of quality of analyses. The two rock samples have also been thoroughly studied spectrographically and petrographically. Detailed reports of all the studies will be published.

  15. The "Key" Method of Identifying Igneous and Metamorphic Rocks in Introductory Laboratory.

    ERIC Educational Resources Information Center

    Eves, Robert Leo; Davis, Larry Eugene

    1987-01-01

    Proposes that identification keys provide an orderly strategy for the identification of igneous and metamorphic rocks in an introductory geology course. Explains the format employed in the system and includes the actual key guides for both igneous and metamorphic rocks. (ML)

  16. The Impact of Space Flight on Survival and Interaction of Cupriavidus metallidurans CH34 with Basalt, a Volcanic Moon Analog Rock

    PubMed Central

    Byloos, Bo; Coninx, Ilse; Van Hoey, Olivier; Cockell, Charles; Nicholson, Natasha; Ilyin, Vyacheslav; Van Houdt, Rob; Boon, Nico; Leys, Natalie

    2017-01-01

    Microbe-mineral interactions have become of interest for space exploration as microorganisms could be used to biomine from extra-terrestrial material and extract elements useful as micronutrients in life support systems. This research aimed to identify the impact of space flight on the long-term survival of Cupriavidus metallidurans CH34 in mineral water and the interaction with basalt, a lunar-type rock in preparation for the ESA spaceflight experiment, BIOROCK. Therefore, C. metallidurans CH34 cells were suspended in mineral water supplemented with or without crushed basalt and send for 3 months on board the Russian FOTON-M4 capsule. Long-term storage had a significant impact on cell physiology and energy status (by flow cytometry analysis, plate count and intracellular ATP measurements) as 60% of cells stored on ground lost their cell membrane potential, only 17% were still active, average ATP levels per cell were significantly lower and cultivability dropped to 1%. The cells stored in the presence of basalt and exposed to space flight conditions during storage however showed less dramatic changes in physiology, with only 16% of the cells lost their cell membrane potential and 24% were still active, leading to a higher cultivability (50%) and indicating a general positive effect of basalt and space flight on survival. Microbe-mineral interactions and biofilm formation was altered by spaceflight as less biofilm was formed on the basalt during flight conditions. Leaching from basalt also changed (measured with ICP-OES), showing that cells release more copper from basalt and the presence of cells also impacted iron and magnesium concentration irrespective of the presence of basalt. The flight conditions thus could counteract some of the detrimental effects observed after the 3 month storage conditions. PMID:28503167

  17. The Impact of Space Flight on Survival and Interaction of Cupriavidus metallidurans CH34 with Basalt, a Volcanic Moon Analog Rock.

    PubMed

    Byloos, Bo; Coninx, Ilse; Van Hoey, Olivier; Cockell, Charles; Nicholson, Natasha; Ilyin, Vyacheslav; Van Houdt, Rob; Boon, Nico; Leys, Natalie

    2017-01-01

    Microbe-mineral interactions have become of interest for space exploration as microorganisms could be used to biomine from extra-terrestrial material and extract elements useful as micronutrients in life support systems. This research aimed to identify the impact of space flight on the long-term survival of Cupriavidus metallidurans CH34 in mineral water and the interaction with basalt, a lunar-type rock in preparation for the ESA spaceflight experiment, BIOROCK. Therefore, C. metallidurans CH34 cells were suspended in mineral water supplemented with or without crushed basalt and send for 3 months on board the Russian FOTON-M4 capsule. Long-term storage had a significant impact on cell physiology and energy status (by flow cytometry analysis, plate count and intracellular ATP measurements) as 60% of cells stored on ground lost their cell membrane potential, only 17% were still active, average ATP levels per cell were significantly lower and cultivability dropped to 1%. The cells stored in the presence of basalt and exposed to space flight conditions during storage however showed less dramatic changes in physiology, with only 16% of the cells lost their cell membrane potential and 24% were still active, leading to a higher cultivability (50%) and indicating a general positive effect of basalt and space flight on survival. Microbe-mineral interactions and biofilm formation was altered by spaceflight as less biofilm was formed on the basalt during flight conditions. Leaching from basalt also changed (measured with ICP-OES), showing that cells release more copper from basalt and the presence of cells also impacted iron and magnesium concentration irrespective of the presence of basalt. The flight conditions thus could counteract some of the detrimental effects observed after the 3 month storage conditions.

  18. The Usability of Noise Level from Rock Cutting for the Prediction of Physico-Mechanical Properties of Rocks

    NASA Astrophysics Data System (ADS)

    Delibalta, M. S.; Kahraman, S.; Comakli, R.

    2015-11-01

    Because the indirect tests are easier and cheaper than the direct tests, the prediction of rock properties from the indirect testing methods is important especially for the preliminary investigations. In this study, the predictability of the physico-mechanical rock properties from the noise level measured during cutting rock with diamond saw was investigated. Noise measurement test, uniaxial compressive strength (UCS) test, Brazilian tensile strength (BTS) test, point load strength (Is) test, density test, and porosity test were carried out on 54 different rock types in the laboratory. The results were statistically analyzed to derive estimation equations. Strong correlations between the noise level and the mechanical rock properties were found. The relations follow power functions. Increasing rock strength increases the noise level. Density and porosity also correlated strongly with the noise level. The relations follow linear functions. Increasing density increases the noise level while increasing porosity decreases the noise level. The developed equations are valid for the rocks with a compressive strength below 150 MPa. Concluding remark is that the physico-mechanical rock properties can reliably be estimated from the noise level measured during cutting the rock with diamond saw.

  19. Laboratory measurements of P- and S-wave anisotropy in synthetic rocks by 3D printing

    NASA Astrophysics Data System (ADS)

    Kong, L.; Ostadhassan, M.; Tamimi, N.; Li, C.; Alexeyev, A.

    2017-12-01

    Synthetic rocks have been widely used to realize the models with controlled factors in rock physics and geomechanics experiments. Additive manufacturing technology, known as 3D printing, is becoming a popular method to produce the synthetic rocks as the advantages of timesaving, economics, and control. In terms of mechanical properties, the duplicability of 3D printed rock towards a natural rock has been studied whereas the seismic anisotropy still remains unknown as being the key factor in conducting rock physics experiments. This study utilized a 3D printer with gypsum as the ink to manufacture a series of synthetic rocks that have the shapes of octagonal prisms, with half of them printed from lateral and another half from the bottom. An ultrasonic investigation system was set up to measure the P- and S- wave velocities at different frequencies while samples were under dry conditions. The results show the impact of layered property on the P- and S- wave velocities. The measurement results were compared with the predicted results of Hudson model, demonstrating that the synthetic rock from 3D printing is a transverse isotropic model. The seismic anisotropy indicates that the availability of using 3D printed rocks to duplicate natural rocks for the purpose of recreating the experiments of rock physics. Future experiments will be performed on the dependence of seismic anisotropy on fracture geometry and density in 3D printed synthetic rocks.

  20. Low-temperature water-rock interactions in bedrock aquifers of southern Rhode Island: Results of laboratory simulations

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Veeger, A.I.; Moulton, K.L.

    1993-03-01

    The nature of low-temperature chemical reactions occurring in bedrock aquifers of southern Rhode Island was investigated in the laboratory using flow-through columns. Crushed samples of Narragansett Pier Granite (NPG), Scituate Granite Gneiss (SGG), Hope Valley Alaskite Gneiss (HVAG) and Ten Rod Granite Gneiss (TRGG) were placed in flow-through columns. Water was circulated through the columns at a 3 ml/min and maintained at 25 C and at equilibrium with atmospheric carbon dioxide. Samples were collected from the columns at increasing time intervals and were analyzed for pH, conductivity, major cations and anions, and silica. The leachate compositions show that distinctive chemicalmore » differences can be expected in ground water that flows through each of these different rock types. Chemical modeling of the leachate solutions shows that reactions involving plagioclase feldspar (albiteoligoclase), reactive accessory minerals such as sphene, and, to a lesser degree, potassium feldspar and biotite, dominate the solution chemistry, with amorphous oxides and aluminosilicates formed as products of the weathering reactions. Small concentrations of reactive minerals may profoundly affect the composition of the leachate. Batch experiments using mineral separates revealed that the calcium in the NPG leachate was almost entirely attributable to sphene which comprises less than 1% of the rock.« less

  1. The Rotational Spectrum of Anti-Ethylamine (CH3CH2NH2) from 10 to 270 GHz: A Laboratory Study and Astronomical Search in Sgr B2(N)

    NASA Astrophysics Data System (ADS)

    Apponi, A. J.; Sun, M.; Halfen, D. T.; Ziurys, L. M.; Müller, H. S. P.

    2008-02-01

    The pure rotational spectrum of the lowest energy (anti-) conformer of ethylamine (CH3CH2NH2) has been measured in the frequency range of 10-270 GHz. The spectrum was recorded using both millimeter-wave absorption spectroscopy and Fourier transform microwave (FTMW) techniques. Ten rotational transitions of this molecule were recorded in the frequency range of 10-40 GHz using FTMW methods, resulting in the assignment of 53 quadrupole-resolved hyperfine lines; in the millimeter-wave region (48-270 GHz), nearly 600 transitions were assigned to the ground (anti-) state. The amine group in CH3CH2NH2 undergoes inversion, resulting in a doubling that is frequently small and most apparent in the low-frequency K-doubling transitions. In addition, seemingly random rotational levels of this molecule were found to be significantly perturbed. The cause of these perturbations is presently uncertain, but torsion-rotation interactions with the higher lying gauche conformers seem to be a likely explanation. An astronomical search was conducted for ethylamine toward Sgr B2(N) using the Kitt Peak 12 m antenna and the Sub-Millimeter Telescope (SMT) of the Arizona Radio Observatory. Frequencies of 70 favorable rotational transitions were observed in this search, which covered the range 68-263 GHz. Ethylamine was not conclusively detected in Sgr B2(N), with an upper limit to the column density of (1-8) × 1013 cm-2 with f(CH3CH2NH2/H2) ~ (0.3-3) × 10-11, assuming a rotational temperature of 50-220 K. These observations indicate a gas-phase CH3CH2NH2/CH3NH2 ratio of <0.001-0.01, in contrast to the nearly equal ratio suggested by the acid hydrolysis of cometary solids from the Stardust mission.

  2. New Rock Abrasivity Test Method for Tool Life Assessments on Hard Rock Tunnel Boring: The Rolling Indentation Abrasion Test (RIAT)

    NASA Astrophysics Data System (ADS)

    Macias, F. J.; Dahl, F.; Bruland, A.

    2016-05-01

    The tunnel boring machine (TBM) method has become widely used and is currently an important presence within the tunnelling industry. Large investments and high geological risk are involved using TBMs, and disc cutter consumption has a great influence on performance and cost, especially in hard rock conditions. Furthermore, reliable cutter life assessments facilitate the control of risk as well as avoiding delays and budget overruns. Since abrasive wear is the most common process affecting cutter consumption, good laboratory tests for rock abrasivity assessments are needed. A new abrasivity test method by rolling disc named Rolling Indentation Abrasion Test (RIAT) has been developed. The goal of the new test design and procedure is to reproduce wear behaviour on hard rock tunnel boring in a more realistic way than the traditionally used methods. Wear by rolling contact on intact rock samples is introduced and several rock types, covering a wide rock abrasiveness range, have been tested by RIAT. The RIAT procedure indicates a great ability of the testing method to assess abrasive wear on rolling discs. In addition and to evaluate the newly developed RIAT test method, a comprehensive laboratory testing programme including the most commonly used abrasivity test methods and the mineral composition were carried out. Relationships between the achieved results from conventional testing and RIAT results have been analysed.

  3. Boring and Sealing Rock with Directed Energy Millimeter-Waves

    NASA Astrophysics Data System (ADS)

    Woskov, P.; Einstein, H. H.; Oglesby, K.

    2015-12-01

    Millimeter-wave directed energy is being investigated to penetrate into deep crystalline basement rock formations to lower well costs and to melt rocks, metals, and other additives to seal wells for applications that include nuclear waste storage and geothermal energy. Laboratory tests have established that intense millimeter-wave (MMW) beams > 1 kW/cm2 can melt and/ or vaporize hard crystalline rocks. In principle this will make it possible to create open boreholes and a method to seal them with a glass/ceramic liner and plug formed from the original rock or with other materials. A 10 kW, 28 GHz commercial (CPI) gyrotron system with a launched beam diameter of about 32 mm was used to heat basalt, granite, limestone, and sandstone specimens to temperatures over 2500 °C to create melts and holes. A calibrated 137 GHz radiometer view, collinear with the heating beam, monitored real time peak rock temperature. A water load surrounding the rock test specimen primarily monitored unabsorbed power at 28 GHz. Power balance analysis of the laboratory observations shows that the temperature rise is limited by radiative heat loss, which would be expected to be trapped in a borehole. The analysis also indicates that the emissivity (absorption efficiency) in the radiated infrared range is lower than the emissivity at 28 GHz, giving the MMW frequency range an important advantage for rock melting. Strength tests on one granite type indicated that heating the rock initially weakens it, but with exposure to higher temperatures the resolidified black glassy product regains strength. Basalt was the easiest to melt and penetrate, if a melt leak path was provided, because of its low viscosity. Full beam holes up to about 50 mm diameter (diffraction increased beam size) were achieved through 30 mm thick basalt and granite specimens. Laboratory experiments to form a seal in an existing hole have also been carried out by melting rock and a simulated steel casing.

  4. Fluid geochemistry and soil gas fluxes (CO2-CH4-H2S) at a promissory Hot Dry Rock Geothermal System: The Acoculco caldera, Mexico

    NASA Astrophysics Data System (ADS)

    Peiffer, L.; Bernard-Romero, R.; Mazot, A.; Taran, Y. A.; Guevara, M.; Santoyo, E.

    2014-09-01

    The Acoculco caldera has been recognized by the Mexican Federal Electricity Company (CFE) as a Hot Dry Rock Geothermal System (HDR) and could be a potential candidate for developing an Enhanced Geothermal System (EGS). Apart from hydrothermally altered rocks, geothermal manifestations within the Acoculco caldera are scarce. Close to ambient temperature bubbling springs and soil degassing are reported inside the caldera while a few springs discharge warm water on the periphery of the caldera. In this study, we infer the origin of fluids and we characterize for the first time the soil degassing dynamic. Chemical and isotopic (δ18O-δD) analyses of spring waters indicate a meteoric origin and the dissolution of CO2 and H2S gases, while gas chemical and isotopic compositions (N2/He, 3He/4He, 13C, 15N) reveal a magmatic contribution with both MORB- and arc-type signatures which could be explained by an extension regime created by local and regional fault systems. Gas geothermometry results are in agreement with temperature measured during well drilling (260 °C-300 °C). Absence of well-developed water reservoir at depth impedes re-equilibration of gases upon surface. A multi-gas flux survey including CO2, CH4 and H2S measurements was performed within the caldera. Using the graphical statistical analysis (GSA) approach, CO2 flux measurements were classified in two populations. Population A, representing 95% of measured fluxes is characterized by low values (mean: 18 g m- 2 day- 1) while the remaining 5% fluxes belonging to Population B are much higher (mean: 5543 g m- 2 day- 1). This low degassing rate probably reflects the low permeability of the system, a consequence of the intense hydrothermal alteration observed in the upper 800 m of volcanic rocks. An attempt to interpret the origin and transport mechanism of these fluxes is proposed by means of flux ratios as well as by numerical modeling. Measurements with CO2/CH4 and CO2/H2S flux ratios similar to mass ratios

  5. Rock geochemistry induces stress and starvation responses in the bacterial proteome.

    PubMed

    Bryce, Casey C; Le Bihan, Thierry; Martin, Sarah F; Harrison, Jesse P; Bush, Timothy; Spears, Bryan; Moore, Alanna; Leys, Natalie; Byloos, Bo; Cockell, Charles S

    2016-04-01

    Interactions between microorganisms and rocks play an important role in Earth system processes. However, little is known about the molecular capabilities microorganisms require to live in rocky environments. Using a quantitative label-free proteomics approach, we show that a model bacterium (Cupriavidus metallidurans CH34) can use volcanic rock to satisfy some elemental requirements, resulting in increased rates of cell division in both magnesium- and iron-limited media. However, the rocks also introduced multiple new stresses via chemical changes associated with pH, elemental leaching and surface adsorption of nutrients that were reflected in the proteome. For example, the loss of bioavailable phosphorus was observed and resulted in the upregulation of diverse phosphate limitation proteins, which facilitate increase phosphate uptake and scavenging within the cell. Our results revealed that despite the provision of essential elements, rock chemistry drives complex metabolic reorganization within rock-dwelling organisms, requiring tight regulation of cellular processes at the protein level. This study advances our ability to identify key microbial responses that enable life to persist in rock environments. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

  6. The effect of rock fabric on P-wave velocity distribution in amphibolites

    NASA Astrophysics Data System (ADS)

    Vajdová, V.; Přikryl, R.; Pros, Z.; Klíma, K.

    1999-07-01

    This study presents contribution to the laboratory investigation of elastic properties and rock fabric of amphibolites. P-wave velocity was determined on four spherical samples prepared from a shallow borehole core. The measurement was conducted in 132 directions under various conditions of hydrostatic pressure (up to 400 MPa). The rock fabric was investigated by image analysis of thin sections that enabled precise determination of grain size, modal composition and shape parameters of rock-forming minerals. Laboratory measurement of P-waves revealed pseudoorthorhombic symmetry of rock fabric in amphibolites studied. This symmetry reflects rocks' macro- and microfabric. Maximum P-wave velocity corresponds to the macroscopically visible stretching lineation. Minimum P-wave velocity is oriented perpendicular to the foliation plane. The average grain size is the main microstructural factor controlling mean P-wave velocity.

  7. A rigorous detection of interstellar CH3NCO: An important missing species in astrochemical networks.

    PubMed

    Cernicharo, J; Kisiel, Z; Tercero, B; Kolesniková, L; Medvedev, I R; López, A; Fortman, S; Winnewisser, M; de Lucia, F C; Alonso, J L; Guillemin, J-C

    2016-03-01

    The recent analysis of the composition of the frozen surface of comet 67P/Churyumov-Gerasimenko has revealed a significant number of complex organic molecules. Methyl isocyanate (CH 3 NCO) is one of the more abundant species detected on the comet surface. In this work we report extensive characterization of its rotational spectrum resulting in a list of 1269 confidently assigned laboratory lines and its detection in space towards the Orion clouds where 399 lines of the molecule have been unambiguously identified. We find that the limited mm-wave laboratory data reported prior to our work require some revision. The abundance of CH 3 NCO in Orion is only a factor of ten below those of HNCO and CH 3 CN. Unlike the molecular abundances in the coma of comets, which correlate with those of warm molecular clouds, molecular abundances in the gas phase in Orion are only weakly correlated with those measured on the comet surface. We also compare our abundances with those derived recently for this molecule towards Sgr B2 (Halfen et al. 2015). A more accurate abundance of CH 3 NCO is provided for this cloud based on our extensive laboratory work.

  8. 19. ROOM 34 AT WEST END OF LABORATORY, THAT FORMERLY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    19. ROOM 34 AT WEST END OF LABORATORY, THAT FORMERLY HOUSED ROCK CUTTING EQUIPMENT. NOTE BLACKED OUT ORIGINAL WINDOW AT LEFT. - U.S. Geological Survey, Rock Magnetics Laboratory, 345 Middlefield Road, Menlo Park, San Mateo County, CA

  9. First look at rock & soil properties

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The earliest survey of spectral properties of the rocks and soils surrounding Pathfinder was acquired as a narrow strip covering the region just beyond the where the rover made its egress from the lander. The wavelength filters used, all in the binocular camera's right eye, cover mainly visible wavelengths. These data reveal at least five kinds of rocks and soil in the immediate vicinity of the lander. All of the spectra are ratioed to the mean spectrum of bright red drift to highlight the differences. Different occurrences of drift (pink spectra) are closely similar. Most of the rocks (black spectra) have a dark gray color, and are both darker and less red than the drift, suggesting less weathering. Typical soils (green spectra) are intermediate in properties to the rocks and drift. Both these data and subsequent higher resolution images show that the typical soil consists of a mixture of drift and small dark gray particles resembling the rock. However, two other kinds of materials are significantly different from the rocks and drift. Pinkish or whitish pebbles and crusts on some of the rocks (blue spectra) are brighter in blue light and darker in near-infrared light than is the drift, and they lack the spectral characteristics closely associated with iron minerals. Dark red soils in the lee of several rocks are about as red as the drift, but consistently darker. The curvature in the spectrum at visible wavelengths suggests either more ferric iron minerals than in the drift or a larger particle size.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator. JPL is an operating division

  10. Tightness of Salt Rocks and Fluid Percolation

    NASA Astrophysics Data System (ADS)

    Lüdeling, C.; Minkley, W.; Brückner, D.

    2016-12-01

    Salt formations are used for storage of oil and gas and as waste repositiories because of their excellent barrier properties. We summarise the current knowledge regarding fluid tightness of saliferous rocks, in particular rock salt. Laboratory results, in-situ observations and natural analogues, as well as theoretical and numerical investigations, indicate that pressure-driven percolation is the most important mechanism for fluid transport: If the fluid pressure exceeds the percolation threshold, i.e. the minor principal stress, the fluid can open up grain boundaries, create connected flow paths and initiate directed migration in the direction of major principal stress. Hence, this mechanism provides the main failure mode for rock salt barriers, where integrity can be lost if the minor principal stress is lowered, e.g. due to excavations or thermomechanical uplift. We present new laboratory experiments showing that there is no fluid permeation below the percolation threshold also at high temperatures and pressures, contrary to recent claims in the literature.

  11. 28. MODIFIED CHAIN SAW FOR CUTTING ROCK CORES; BRUNTON COMPASS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    28. MODIFIED CHAIN SAW FOR CUTTING ROCK CORES; BRUNTON COMPASS STAND FOR DETERMINING CORE'S FIELD ORIENTATION; INSECTICIDE DISPENSER MODIFIED TO LUBRICATE CORE DRILLING PROCESS. - U.S. Geological Survey, Rock Magnetics Laboratory, 345 Middlefield Road, Menlo Park, San Mateo County, CA

  12. Experimental acidification of Little Rock Lake (Wisconsin): fish research approach and early responses.

    PubMed

    Swenson, W A; McCormick, J H; Simonson, T D; Jensen, K M; Eaton, J G

    1989-01-01

    One goal of research at Little Rock Lake, Wisconsin, is to enhance understanding of lake acidification effects on warm- and cool-water fishery resources. The Little Rock Lake fish assemblage is characteristic of many acid sensitive waters in North America and is dominated by yellow perch (Percidae) and sunfishes (Centrarchidae). Analyses of reproduction, early survival and growth rates in the field were designed around the differing reproductive modes of these taxa. Complementary laboratory research on early life stages was conducted to assist in isolating direct effect mechanisms and to determine the reliability of laboratory results in predicting field response. Preliminary findings suggest that lake acidification to pH 5.6 has not influenced reproductive activity of the four most abundant fish species. However, the field results suggest that year-class failure of rock bass (Ambloplites rupestris) may be occurring due to reduced survival of early life stages. Reduced growth and food conversion efficiency of Age 0 largemouth bass (Micropterus salmoides) is also suggested. The laboratory bioassays indicate rock bass is the most acid-sensitive Little Rock Lake species tested. However, rock bass fry survival was not significantly affected until pH was reduced from 5.6 to 5.0.

  13. Supplementation of Male Pheromone on Rock Substrates Attracts Female Rock Lizards to the Territories of Males: A Field Experiment

    PubMed Central

    Martín, José; López, Pilar

    2012-01-01

    Background Many animals produce elaborated sexual signals to attract mates, among them are common chemical sexual signals (pheromones) with an attracting function. Lizards produce chemical secretions for scent marking that may have a role in sexual selection. In the laboratory, female rock lizards (Iberolacerta cyreni) prefer the scent of males with more ergosterol in their femoral secretions. However, it is not known whether the scent-marks of male rock lizards may actually attract females to male territories in the field. Methodology/Principal Findings In the field, we added ergosterol to rocks inside the territories of male lizards, and found that this manipulation resulted in increased relative densities of females in these territories. Furthermore, a higher number of females were observed associated to males in manipulated plots, which probably increased mating opportunities for males in these areas. Conclusions/Significance These and previous laboratory results suggest that female rock lizards may select to settle in home ranges based on the characteristics of scent-marks from conspecific males. Therefore, male rock lizards might attract more females and obtain more matings by increasing the proportion of ergosterol when scent-marking their territories. However, previous studies suggest that the allocation of ergosterol to secretions may be costly and only high quality males could afford it, thus, allowing the evolution of scent-marks as an honest sexual display. PMID:22253895

  14. A transient laboratory method for determining the hydraulic properties of 'tight' rocks-I. Theory

    USGS Publications Warehouse

    Hsieh, P.A.; Tracy, J.V.; Neuzil, C.E.; Bredehoeft, J.D.; Silliman, Stephen E.

    1981-01-01

    Transient pulse testing has been employed increasingly in the laboratory to measure the hydraulic properties of rock samples with low permeability. Several investigators have proposed a mathematical model in terms of an initial-boundary value problem to describe fluid flow in a transient pulse test. However, the solution of this problem has not been available. In analyzing data from the transient pulse test, previous investigators have either employed analytical solutions that are derived with the use of additional, restrictive assumptions, or have resorted to numerical methods. In Part I of this paper, a general, analytical solution for the transient pulse test is presented. This solution is graphically illustrated by plots of dimensionless variables for several cases of interest. The solution is shown to contain, as limiting cases, the more restrictive analytical solutions that the previous investigators have derived. A method of computing both the permeability and specific storage of the test sample from experimental data will be presented in Part II. ?? 1981.

  15. Kinetics of OH- and Cl-initiated oxidation of CH2dbnd CHC(O)O(CH2)2CH3 and CH2dbnd CHCH2C(O)O(CH2)2CH3 and fate of the alkoxy radicals formed

    NASA Astrophysics Data System (ADS)

    Rivela, Cynthia; Blanco, María B.; Teruel, Mariano A.

    2016-05-01

    Rate coefficients of the reactions of OH and Cl radicals with vinyl and allyl butyrate were determined for the first time at 298 K and 1 atm using the relative method to be (in cm3 molecule-1 s-1): k1(OH + CH2dbnd CHC(O)O(CH2)2CH3) = (2.61 ± 0.31) × 10-11, k2(Cl + CH2dbnd CHC(O)O(CH2)2CH3) = (2.48 ± 0.89) × 10-10, k3(OH + CH2dbnd CHCH2C(O)O(CH2)2CH3) = (2.89 ± 0.31) × 10-11, and k4(Cl + CH2dbnd CHCH2C(O)O(CH2)2CH3) = (2.25 ± 0.96) × 10-10. Reactivity trends and atmospheric lifetimes of esters are presented. Additionally, a product study shown butyric acid and polifunctional products for the reactions of vinyl and allyl butyrate, respectively and general mechanism is proposed.

  16. Energy Efficiency, Water Efficiency, and Renewable Energy Site Assessment: Seneca Rocks Discovery Center, Seneca Rocks, West Virginia

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kiatreungwattana, Kosol; Salasovich, James; Kandt, Alicen

    As part of ongoing efforts by the U.S. Forest Service to reduce energy use and incorporate renewable energy technologies into its facilities, the Department of Energy's National Renewable Energy Laboratory performed an energy efficiency and renewable energy site assessment of the Seneca Rocks Discovery Center in Seneca Rocks, West Virginia. This report documents the findings of this assessment, and provides site-specific information for the implementation of energy and water conservation measures, and renewable energy measures.

  17. The origin, source, and cycling of methane in deep crystalline rock biosphere.

    PubMed

    Kietäväinen, Riikka; Purkamo, Lotta

    2015-01-01

    The emerging interest in using stable bedrock formations for industrial purposes, e.g., nuclear waste disposal, has increased the need for understanding microbiological and geochemical processes in deep crystalline rock environments, including the carbon cycle. Considering the origin and evolution of life on Earth, these environments may also serve as windows to the past. Various geological, chemical, and biological processes can influence the deep carbon cycle. Conditions of CH4 formation, available substrates and time scales can be drastically different from surface environments. This paper reviews the origin, source, and cycling of methane in deep terrestrial crystalline bedrock with an emphasis on microbiology. In addition to potential formation pathways of CH4, microbial consumption of CH4 is also discussed. Recent studies on the origin of CH4 in continental bedrock environments have shown that the traditional separation of biotic and abiotic CH4 by the isotopic composition can be misleading in substrate-limited environments, such as the deep crystalline bedrock. Despite of similarities between Precambrian continental sites in Fennoscandia, South Africa and North America, where deep methane cycling has been studied, common physicochemical properties which could explain the variation in the amount of CH4 and presence or absence of CH4 cycling microbes were not found. However, based on their preferred carbon metabolism, methanogenic microbes appeared to have similar spatial distribution among the different sites.

  18. The origin, source, and cycling of methane in deep crystalline rock biosphere

    PubMed Central

    Kietäväinen, Riikka; Purkamo, Lotta

    2015-01-01

    The emerging interest in using stable bedrock formations for industrial purposes, e.g., nuclear waste disposal, has increased the need for understanding microbiological and geochemical processes in deep crystalline rock environments, including the carbon cycle. Considering the origin and evolution of life on Earth, these environments may also serve as windows to the past. Various geological, chemical, and biological processes can influence the deep carbon cycle. Conditions of CH4 formation, available substrates and time scales can be drastically different from surface environments. This paper reviews the origin, source, and cycling of methane in deep terrestrial crystalline bedrock with an emphasis on microbiology. In addition to potential formation pathways of CH4, microbial consumption of CH4 is also discussed. Recent studies on the origin of CH4 in continental bedrock environments have shown that the traditional separation of biotic and abiotic CH4 by the isotopic composition can be misleading in substrate-limited environments, such as the deep crystalline bedrock. Despite of similarities between Precambrian continental sites in Fennoscandia, South Africa and North America, where deep methane cycling has been studied, common physicochemical properties which could explain the variation in the amount of CH4 and presence or absence of CH4 cycling microbes were not found. However, based on their preferred carbon metabolism, methanogenic microbes appeared to have similar spatial distribution among the different sites. PMID:26236303

  19. SAPHYR: the Swiss Atlas of PHYsical properties of Rocks

    NASA Astrophysics Data System (ADS)

    Wenning, Q. C.; Zappone, A. S.; Kissling, E.

    2015-12-01

    The Swiss Atlas of PHYsical properties of Rocks (SAPHYR) is a multi-year project, aiming to compile a comprehensive data set on physical properties of rocks exposed in Switzerland and surrounding areas. The ultimate goal of SAPHYR is to make these data accessible to an open and wide public, such as industrial, engineering, land and resource planning companies, as well as academic institutions. Since the early sixties worldwide geophysicists, petrologists, and engineers, focused their work on laboratory measurements of rocks physical properties, and their relations with microstructures, mineralogical compositions and other rock parameters, in the effort to constrain the geological interpretation of geophysical surveys. In combination with efforts to investigate deep structure of the continental crust by controlled source seismology, laboratories capable to reproduce pressure and temperature conditions to depth of 50km and more collected measurements of various parameters on a wide variety of rock types. In recent years, the increasing interest on non-traditional energy supply, (deep geothermal energy, shale gas) and CO2 storage renovated the interests in physical characterization of the deep underground. The idea to organize those laboratory data into a geographically referenced database (GIS) is supported by the Swiss Commission for Geophysics. The data refer to density and porosity, seismic, magnetic, thermal properties, permeability and electrical properties. An effort has been placed on collecting samples and measuring the physical properties of lithologies that are poorly documented in literature. The phase of laboratory measurements is still in progress. At present SAPHYR focuses towards developing a 3-D physical properties model of the Swiss subsurface, using the structure of the exposed geology, boreholes data and seismic surveys, combined with lab determined pressure and temperature derivatives. An early version of the final product is presented here.

  20. Laboratory Noble Gas Migration Experiments through Rock

    NASA Astrophysics Data System (ADS)

    Broome, S.; Cashion, A.; Feldman, J.; Sussman, A. J.; Swanson, E.; Wilson, J.

    2016-12-01

    The Underground Nuclear Explosion Signatures Experiment (UNESE) was created to address science and research and development aspects associated with nuclear explosion verification and nuclear nonproliferation with a focus on non-prompt signals. A critical component of the UNESE program is a realistic understanding of the post-detonation processes and changes in the environment that produce observable physical and radio-chemical signatures. As such, an understanding of noble gas migration properties through various lithologies is essential. Here we present an empirical methodology to measure tortuosity on well-characterized rhyolitic tuffs and lavas. Tortuosity is then compared with microfracture networks characterized by microscopy. To quantify tortuosity, a pressurized (1500 mbar) fixed volume of argon is expanded into a sample under high vacuum (0.200 mbar). A quadrupole mass spectrometer (QMS) is used to measure argon downstream of the sample in real time, allowing the time-series gas arrival curve to be characterized for each sample. To evaluate the method, blank samples have been machined to correspond with tortuosities of 1, 2, and 4 in conjunction with a restricted-flow valve to mimic rock sample permeability. Data from the blanks are analyzed with this system to correct for system effects on gas arrival. High vacuum is maintained in the QMS system during sampling by precise metering of the gas through a leak valve with active feedback control which allows arrival time and concentration of argon to be established in real time. Along with a comprehensive characterization of the rock and fracture properties, the parameters derived from these experiments will provide invaluable insight into the three-dimensional structure of damage zones, the production of temporally variable signatures and the methods to best detect underground nuclear explosion signatures. SAND2016-7309 A

  1. Rock Physical Interpretation of the Relationship between Dynamic and Static Young's Moduli of Sedimentary Rocks

    NASA Astrophysics Data System (ADS)

    Takahashi, T.

    2017-12-01

    The static Young's modulus (deformability) of a rock is indispensable for designing and constructing tunnels, dams and underground caverns in civil engineering. Static Young's modulus which is an elastic modulus at large strain level is usually obtained with the laboratory tests of rock cores sampled in boreholes drilled in a rock mass. A deformability model of the entire rock mass is then built by extrapolating the measurements based on a rock mass classification obtained in geological site characterization. However, model-building using data obtained from a limited number of boreholes in the rock mass, especially a complex rock mass, may cause problems in the accuracy and reliability of the model. On the other hand, dynamic Young's modulus which is the modulus at small strain level can be obtained from seismic velocity. If dynamic Young's modulus can be rationally converted to static one, a seismic velocity model by the seismic method can be effectively used to build a deformability model of the rock mass. In this study, we have, therefore, developed a rock physics model (Mavko et al., 2009) to estimate static Young's modulus from dynamic one for sedimentary rocks. The rock physics model has been generally applied to seismic properties at small strain level. In the proposed model, however, the sandy shale model, one of rock physics models, is extended for modeling the static Young's modulus at large strain level by incorporating the mixture of frictional and frictionless grain contacts into the Hertz-Mindlin model. The proposed model is verified through its application to the dynamic Young's moduli derived from well log velocities and static Young's moduli measured in the tri-axial compression tests of rock cores sampled in the same borehole as the logs were acquired. This application proves that the proposed rock physics model can be possibly used to estimate static Young's modulus (deformability) which is required in many types of civil engineering applications

  2. Integrating the ChE Curriculum via a Recurring Laboratory

    ERIC Educational Resources Information Center

    Kubilius, Matthew B.; Tu, Raymond S.; Anderson, Ryan

    2014-01-01

    A recurring framework has been integrated throughout the curriculum via a Continuously Stirred Tank Reactor (CSTR) platform. This laboratory is introduced during the material and energy balance course, and subsequent courses can use these results when explaining more advanced concepts. Further, this laboratory gives students practical experience…

  3. Was Early Mars Warmed by CH4?

    NASA Astrophysics Data System (ADS)

    Justh, H. L.; Kasting, J. F.

    2001-12-01

    Images from the Mariner, Viking and Mars Global Surveyor missions have shown geologic features on the Martian surface that seem to indicate an earlier period of hydrologic activity. Many researchers have suggested that the early Martian climate was more Earth-like with a Ts of 273 K or higher. The presence of liquid water would require a greenhouse effect much larger than needed at present since S0 is 25% lower 3.8 billion years ago when the channels are thought to have formed. Research into the effects of CO2 clouds upon the climate of early Mars have yielded results that would not effectively warm the surface to the temperature needed to account for the presence of liquid water. Forget and Pierrehumbert (Science, 1997) showed that large crystals of CO2 ice in clouds that form in the upper troposphere would produce a strong warming effect. Obtaining mean surface temperatures above 273 K would require 100% cloud cover, a condition that is unrealistic for early Mars. It has also been shown that any reduction in cloud cover makes it difficult to achieve warm Martian surface temperatures except at high pressures. CO2 clouds could also cool the Martian surface if they were low and optically thick. CO2 ice may be hard to nucleate, leading to the formation of very large particles (Glandorf, private communication). CH4 has been suggested as an important greenhouse gas on the early Earth. This has led us to look at CH4 as a potential solution to the early Mars climate issue. To investigate the possible warming effect of CH4, we utilized a modified, one-dimensional, radiative-convective climate model that has been used in previous studies of the early Martian climate. New calculations of the effects of CH4 upon the early Martian climate will be presented. The use of CH4 to warm the surface of early Mars does not necessarily imply the presence of life on Mars. Abiotic sources of CH4, such as serpentinization of ultramafic rocks, could supply the concentrations needed to warm

  4. Swiss Atlas of PHYsical properties of Rocks (SAPHYR)

    NASA Astrophysics Data System (ADS)

    Zappone, Alba; Kissling, Eduard

    2015-04-01

    The Swiss Atlas of PHYsical properties of Rocks (SAPHYR), is a multi-year project, funded entirely by Swiss Commission for Geophysics (SGPK), with the aim to compile a comprehensive data set in digital form on physical properties of rocks exposed in Switzerland and surrounding regions. The ultimate goal of SAPHYR is to make these data accessible to an open and wide public including industrial, engineering, land and resource planning companies, as well as academic institutions, or simply people interested in geology. Since the early sixties worldwide many scientists, i.e. geophysicists, petrologists, and engineers, focused their work on laboratory measurements of rocks physical properties, and their relations with microstructures, mineralogical compositions and other rock parameters, in the effort to constrain the geological interpretation of geophysical surveys. Particularly in the years in which seismic reflection and refraction crustal scale projects were investigating the deep structures of the Alps, laboratories capable to reproduce the pressure and temperature ranges of the continental crust were collecting measurements of various rock parameters on a wide variety of lithologies, developing in the meantime more and more sophisticated experimental methodologies. In recent years, the increasing interest of European Countries on non-traditional energy supply, (i.e. Deep Geothermal Energy and shale gas) and CO2 storage renovated the interests in physical characterization of the deep underground. SAPHYR aims to organize all those laboratory data into a geographically referenced database (GIS). The data refer to density, porosity, permeability, and seismic, magnetic, thermal and electric properties. In the past years, effort has been placed on collecting samples and measuring the physical properties of lithologies that were poorly documented in literature. The phase of laboratory measurements is still in progress. Recently, SAPHYR project focused towards developing

  5. Anisotropic Poroelasticity in a Rock With Cracks

    NASA Astrophysics Data System (ADS)

    Wong, Teng-Fong

    2017-10-01

    Deformation of a saturated rock in the field and laboratory may occur in a broad range of conditions, ranging from undrained to drained. The poromechanical response is often anisotropic, and in a brittle rock, closely related to preexisting and stress-induced cracks. This can be modeled as a rock matrix embedded with an anisotropic system of cracks. Assuming microisotropy, expressions for three of the poroelastic coefficients of a transversely isotropic rock were derived in terms of the crack density tensor. Together with published results for the five effective elastic moduli, this provides a complete micromechanical description of the eight independent poroelastic coefficients of such a cracked rock. Relatively simple expressions were obtained for the Skempton pore pressure tensor, which allow one to infer the crack density tensor from undrained measurement in the laboratory, and also to infer the Biot-Willis effective stress coefficients. The model assumes a dilute concentration of noninteractive penny-shaped cracks, and it shows good agreement with experimental data for Berea sandstone, with crack density values up to 0.6. Whereas predictions on the storage coefficient and normal components of the elastic stiffness tensor also seem reasonable, significant discrepancy between model and measurement was observed regarding the off-diagonal and shear components of the stiffness. A plausible model had been proposed for development of very strong anisotropy in the undrained response of a fault zone, and the model here placed geometric constraints on the associated fracture system.

  6. Active and passive seismic methods for characterization and monitoring of unstable rock masses: field surveys, laboratory tests and modeling.

    NASA Astrophysics Data System (ADS)

    Colombero, Chiara; Baillet, Laurent; Comina, Cesare; Jongmans, Denis; Vinciguerra, Sergio

    2016-04-01

    Appropriate characterization and monitoring of potentially unstable rock masses may provide a better knowledge of the active processes and help to forecast the evolution to failure. Among the available geophysical methods, active seismic surveys are often suitable to infer the internal structure and the fracturing conditions of the unstable body. For monitoring purposes, although remote-sensing techniques and in-situ geotechnical measurements are successfully tested on landslides, they may not be suitable to early forecast sudden rapid rockslides. Passive seismic monitoring can help for this purpose. Detection, classification and localization of microseismic events within the prone-to-fall rock mass can provide information about the incipient failure of internal rock bridges. Acceleration to failure can be detected from an increasing microseismic event rate. The latter can be compared with meteorological data to understand the external factors controlling stability. On the other hand, seismic noise recorded on prone-to-fall rock slopes shows that the temporal variations in spectral content and correlation of ambient vibrations can be related to both reversible and irreversible changes within the rock mass. We present the results of the active and passive seismic data acquired at the potentially unstable granitic cliff of Madonna del Sasso (NW Italy). Down-hole tests, surface refraction and cross-hole tomography were carried out for the characterization of the fracturing state of the site. Field surveys were implemented with laboratory determination of physico-mechanical properties on rock samples and measurements of the ultrasonic pulse velocity. This multi-scale approach led to a lithological interpretation of the seismic velocity field obtained at the site and to a systematic correlation of the measured velocities with physical properties (density and porosity) and macroscopic features of the granitic cliff (fracturing, weathering and anisotropy). Continuous

  7. Unimolecular reactivity of organotrifluoroborate anions, RBF3- , and their alkali metal cluster ions, M(RBF3 )2- (M = Na, K; R = CH3 , CH3 CH2 , CH3 (CH2 )3 , CH3 (CH2 )5 , c-C3 H5 , C6 H5 , C6 H5 CH2 , CH2 CHCH2 , CH2 CH, C6 H5 CO).

    PubMed

    Bathie, Fiona L B; Bowen, Chris J; Hutton, Craig A; O'Hair, Richard A J

    2018-07-15

    Potassium organotrifluoroborates (RBF 3 K) are important reagents used in organic synthesis. Although mass spectrometry is commonly used to confirm their molecular formulae, the gas-phase fragmentation reactions of organotrifluoroborates and their alkali metal cluster ions have not been previously reported. Negative-ion mode electrospray ionization (ESI) together with collision-induced dissociation (CID) using a triple quadrupole mass spectrometer were used to examine the fragmentation pathways for RBF 3 - (where R = CH 3 , CH 3 CH 2 , CH 3 (CH 2 ) 3 , CH 3 (CH 2 ) 5 , c-C 3 H 5 , C 6 H 5 , C 6 H 5 CH 2 , CH 2 CHCH 2 , CH 2 CH, C 6 H 5 CO) and M(RBF 3 ) 2 - (M = Na, K), while density functional theory (DFT) calculations at the M06/def2-TZVP level were used to examine the structures and energies associated with fragmentation reactions for R = Me and Ph. Upon CID, preferentially elimination of HF occurs for RBF 3 - ions for systems where R = an alkyl anion, whereas R - formation is favoured when R = a stabilized anion. At higher collision energies loss of F - and additional HF losses are sometimes observed. Upon CID of M(RBF 3 ) 2 - , formation of RBF 3 - is the preferred pathway with some fluoride transfer observed only when M = Na. The DFT-calculated relative thermochemistry for competing fragmentation pathways is consistent with the experiments. The main fragmentation pathways of RBF 3 - are HF elimination and/or R - loss. This contrasts with the fragmentation reactions of other organometallate anions, where reductive elimination, beta hydride transfer and bond homolysis are often observed. The presence of fluoride transfer upon CID of Na(RBF 3 ) 2 - but not K(RBF 3 ) 2 - is in agreement with the known fluoride affinities of Na + and K + and can be rationalized by Pearson's HSAB theory. Copyright © 2018 John Wiley & Sons, Ltd.

  8. Infrared absorption of CH3OSO and CD3OSO radicals produced upon photolysis of CH3OS(O)Cl and CD3OS(O)Cl in p-H2 matrices.

    PubMed

    Lee, Yu-Fang; Kong, Lin-Jun; Lee, Yuan-Pern

    2012-03-28

    Irradiation at 239 ± 20 nm of a p-H(2) matrix containing methoxysulfinyl chloride, CH(3)OS(O)Cl, at 3.2 K with filtered light from a medium-pressure mercury lamp produced infrared (IR) absorption lines at 3028.4 (attributable to ν(1), CH(2) antisymmetric stretching), 2999.5 (ν(2), CH(3) antisymmetric stretching), 2950.4 (ν(3), CH(3) symmetric stretching), 1465.2 (ν(4), CH(2) scissoring), 1452.0 (ν(5), CH(3) deformation), 1417.8 (ν(6), CH(3) umbrella), 1165.2 (ν(7), CH(3) wagging), 1152.1 (ν(8), S=O stretching mixed with CH(3) rocking), 1147.8 (ν(9), S=O stretching mixed with CH(3) wagging), 989.7 (ν(10), C-O stretching), and 714.5 cm(-1) (ν(11), S-O stretching) modes of syn-CH(3)OSO. When CD(3)OS(O)Cl in a p-H(2) matrix was used, lines at 2275.9 (ν(1)), 2251.9 (ν(2)), 2083.3 (ν(3)), 1070.3 (ν(4)), 1056.0 (ν(5)), 1085.5 (ν(6)), 1159.7 (ν(7)), 920.1 (ν(8)), 889.0 (ν(9)), 976.9 (ν(10)), and 688.9 (ν(11)) cm(-1) appeared and are assigned to syn-CD(3)OSO; the mode numbers correspond to those used for syn-CH(3)OSO. The assignments are based on the photolytic behavior and a comparison of observed vibrational wavenumbers, infrared intensities, and deuterium isotopic shifts with those predicted with the B3P86∕aug-cc-pVTZ method. Our results extend the previously reported four transient IR absorption bands of gaseous syn-CH(3)OSO near 2991, 2956, 1152, and 994 cm(-1) to 11 lines, including those associated with C-O, O-S, and S=O stretching modes. Vibrational wavenumbers of syn-CD(3)OSO are new. These results demonstrate the advantage of a diminished cage effect of solid p-H(2) such that the Cl atom, produced via UV photodissociation of CH(3)OS(O)Cl in situ, might escape from the original cage to yield isolated CH(3)OSO radicals.

  9. Corrosion of rock anchors in US coal mines

    NASA Astrophysics Data System (ADS)

    Bylapudi, Gopi

    The mining industry is a major consumer of rock bolts in the United States. Due to the high humidity in the underground mining environment, the rock bolts corrode and loose their load bearing capacity which in turn reduces the life expectancy of the ground support and, thus, creates operational difficulties and number of safety concerns[1]. Research on rock anchor corrosion has not been adequately extensive in the past and the effects of several factors in the mine atmosphere and waters are not clearly understood. One of the probable reasons for this lack of research may be attributed to the time required for gathering meaningful data that makes the study of corrosion quite challenging. In this particular work underground water samples from different mines in the Illinois coal basin were collected and the major chemical content was analyzed and used for the laboratory testing. The corrosion performance of the different commercial rock anchors was investigated by techniques such as laboratory immersion tests in five different corrosion chambers, and potentiodynamic polarization tests in simulated ground waters based on the Illinois coal basin. The experiments were conducted with simulate underground mining conditions (corrosive). The tensile strengths were measured for the selected rock anchors taken every 3 months from the salt spray corrosion chambers maintained at different pH values and temperatures. The corrosion potential (Ecorr ), corrosion current (Icorr) and the corresponding corrosion rates (CR) of the selected commercial rock bolts: #5, #6, #6 epoxy coated and #7 forged head rebar steels, #6 and #7 threaded head rebar steels were measured at the solution pH values of 5 and 8 at room temperature. The open circuit potential (OCP) values of the different rock anchors were recorded in 3 selected underground coal mines (A, B & C) in the Illinois coal basin and the data compared with the laboratory electrochemical tests for analyzing the life of the rock

  10. Infrared absorption of CH3OSO detected with time-resolved Fourier-transform spectroscopy.

    PubMed

    Chen, Jin-Dah; Lee, Yuan-Pern

    2011-03-07

    A step-scan Fourier-transform spectrometer coupled with a multipass absorption cell was employed to detect temporally resolved infrared absorption spectra of CH(3)OSO produced upon irradiation of a flowing gaseous mixture of CH(3)OS(O)Cl in N(2) or CO(2) at 248 nm. Two intense transient features with origins near 1152 and 994 cm(-1) are assigned to syn-CH(3)OSO; the former is attributed to overlapping bands at 1154 ± 3 and 1151 ± 3 cm(-1), assigned to the S=O stretching mixed with CH(3) rocking (ν(8)) and the S=O stretching mixed with CH(3) wagging (ν(9)) modes, respectively, and the latter to the C-O stretching (ν(10)) mode at 994 ± 6 cm(-1). Two weak bands at 2991 ± 6 and 2956 ± 3 cm(-1) are assigned as the CH(3) antisymmetric stretching (ν(2)) and symmetric stretching (ν(3)) modes, respectively. Observed vibrational transition wavenumbers agree satisfactorily with those predicted with quantum-chemical calculations at level B3P86∕aug-cc-pVTZ. Based on rotational parameters predicted at that level, the simulated rotational contours of these bands agree satisfactorily with experimental results. The simulation indicates that the S=O stretching mode of anti-CH(3)OSO near 1164 cm(-1) likely makes a small contribution to the observed band near 1152 cm(-1). A simple kinetic model of self-reaction is employed to account for the decay of CH(3)OSO and yields a second-order rate coefficient k=(4 ± 2)×10(-10) cm(3)molecule(-1)s(-1). © 2011 American Institute of Physics.

  11. A vacuum ultraviolet laser pulsed field ionization-photoion study of methane (CH 4): Determination of the appearance energy of methylium from methane with unprecedented precision and the resulting impact on the bond dissociation energies of CH 4 and CH 4 +

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chang, Yih -Chung; Xiong, Bo; Bross, David H.

    Here, we report on the successful implementation of a high-resolution vacuum ultraviolet (VUV) laser pulsed field ionization-photoion (PFI-PI) detection method for the study of unimolecular dissociation of quantum-state- or energy-selected molecular ions. As a test case, we have determined the 0 K appearance energy (AE 0) for the formation of methylium, CH 3 +, from methane, CH 4, as AE 0 (CH 3 +/CH 4) = 14.32271 ± 0.00013 eV. This value has a significantly smaller error limit, but is otherwise consistent with previous laboratory and/or synchrotron-based studies of this dissociative photoionization onset. Furthermore, the sum of the VUV lasermore » PFI-PI spectra obtained for the parent CH 4 + ion and the fragment CH 3 + ions of methane is found to agree with the earlier VUV pulsed field ionization-photoelectron (VUV-PFI-PE) spectrum of methane, providing unambiguous validation of the previous interpretation that the sharp VUV-PFI-PE step observed at the AE 0 (CH 3 +/CH 4) threshold ensues because of higher PFI detection efficiency for fragment CH 3 + than for parent CH 4 +. This, in turn, is a consequence of the underlying high- n Rydberg dissociation mechanism for the dissociative photoionization of CH 4, which was proposed in previous synchrotron-based VUV-PFI-PE and VUV-PFI-PEPICO studies of CH 4. The present highly accurate 0 K dissociative ionization threshold for CH 4 can be utilized to derive accurate values for the bond dissociation energies of methane and methane cation. For methane, the straightforward application of sequential thermochemistry via the positive ion cycle leads to some ambiguity because of two competing VUV-PFI-PE literature values for the ionization energy of methyl radical. The ambiguity is successfully resolved by applying the Active Thermochemical Tables (ATcT) approach, resulting in D 0 (H-CH 3) = 432.463 ± 0.027 kJ/mol and D 0(H-CH 3 +) = 164.701 ± 0.038 kJ/mol.« less

  12. A vacuum ultraviolet laser pulsed field ionization-photoion study of methane (CH 4): Determination of the appearance energy of methylium from methane with unprecedented precision and the resulting impact on the bond dissociation energies of CH 4 and CH 4 +

    DOE PAGES

    Chang, Yih -Chung; Xiong, Bo; Bross, David H.; ...

    2017-03-27

    Here, we report on the successful implementation of a high-resolution vacuum ultraviolet (VUV) laser pulsed field ionization-photoion (PFI-PI) detection method for the study of unimolecular dissociation of quantum-state- or energy-selected molecular ions. As a test case, we have determined the 0 K appearance energy (AE 0) for the formation of methylium, CH 3 +, from methane, CH 4, as AE 0 (CH 3 +/CH 4) = 14.32271 ± 0.00013 eV. This value has a significantly smaller error limit, but is otherwise consistent with previous laboratory and/or synchrotron-based studies of this dissociative photoionization onset. Furthermore, the sum of the VUV lasermore » PFI-PI spectra obtained for the parent CH 4 + ion and the fragment CH 3 + ions of methane is found to agree with the earlier VUV pulsed field ionization-photoelectron (VUV-PFI-PE) spectrum of methane, providing unambiguous validation of the previous interpretation that the sharp VUV-PFI-PE step observed at the AE 0 (CH 3 +/CH 4) threshold ensues because of higher PFI detection efficiency for fragment CH 3 + than for parent CH 4 +. This, in turn, is a consequence of the underlying high- n Rydberg dissociation mechanism for the dissociative photoionization of CH 4, which was proposed in previous synchrotron-based VUV-PFI-PE and VUV-PFI-PEPICO studies of CH 4. The present highly accurate 0 K dissociative ionization threshold for CH 4 can be utilized to derive accurate values for the bond dissociation energies of methane and methane cation. For methane, the straightforward application of sequential thermochemistry via the positive ion cycle leads to some ambiguity because of two competing VUV-PFI-PE literature values for the ionization energy of methyl radical. The ambiguity is successfully resolved by applying the Active Thermochemical Tables (ATcT) approach, resulting in D 0 (H-CH 3) = 432.463 ± 0.027 kJ/mol and D 0(H-CH 3 +) = 164.701 ± 0.038 kJ/mol.« less

  13. Sojourner Sits Near Rock Garden

    NASA Technical Reports Server (NTRS)

    2003-01-01

    The Mars Pathfinder Rover Sojourner is images by the Imager for Mars Pathfinder as it nears the rock 'Wedge.' Part of the Rock Garden is visible in the upper right of the image.

    Pathfinder, a low-cost Discovery mission, is the first of a new fleet of spacecraft that are planned to explore Mars over the next ten years. Mars Global Surveyor, already en route, arrives at Mars on September 11 to begin a two year orbital reconnaissance of the planet's composition, topography, and climate. Additional orbiters and landers will follow every 26 months.

    The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

  14. RESEARCH PAPERS : Evidence for the Blake event in volcanic rocks from Lipari (Aeolian Archipelago)

    NASA Astrophysics Data System (ADS)

    Zanella, Elena; Laurenzi, Marinella A.

    1998-01-01

    Palaeomagnetic and geochronological measurements have been carried out on the late Pleistocene basaltic-andesitic unit of Monte Chirica-Costa Rasa, on the island of Lipari (Aeolian Archipelago). The lava flow sequence is about 10 m thick and has been sampled in detail. Magnetic properties are rather uniform; Curie temperatures of 540° to 580°C, and the saturation IRM reached at applied values of 0.1 T point to titanomagnetite as the main magnetization carrier. Thermal and AF demagnetization have shown the presence of secondary magnetization components. These were removed mostly at 450°-500°C or 20-30 mT, indicating a highly stable ChRM with directions from transitional to reverse. Where a ChRM could not be isolated by application of the demagnetization techniques, the converging remagnetization circles method gave a mean ChRM value fully comparable with that obtained from other methods. 40Ar/39Ar determinations were performed on two lava flows, in the lower and upper parts of the sequence. The former shows a transitional ChRM direction and a whole-rock age of 157+/-12 ka, the latter a reverse direction, a whole-rock age of 143+/-17 ka and a ground-mass age of 128+/-23 ka. The radiometric data and the reconstructed stratigraphy, which indicate ages of 150+/-10 ka and 104+/-3.5 ka, respectively, for the volcanic units at the bottom and top of the Monte Chirica-Costa Rasa unit, suggest that the reverse directions recorded in Lipari are related to the Blake event.

  15. ChIP and ChIP-Related Techniques: Expanding the Fields of Application and Improving ChIP Performance.

    PubMed

    Visa, Neus; Jordán-Pla, Antonio

    2018-01-01

    Protein-DNA interactions in vivo can be detected and quantified by chromatin immunoprecipitation (ChIP). ChIP has been instrumental for the advancement of epigenetics and has set the groundwork for the development of a number of ChIP-related techniques that have provided valuable information about the organization and function of genomes. Here, we provide an introduction to ChIP and discuss the applications of ChIP in different research areas. We also review some of the strategies that have been devised to improve ChIP performance.

  16. A rigorous detection of interstellar CH3NCO: An important missing species in astrochemical networks⋆,⋆⋆

    PubMed Central

    Cernicharo, J.; Kisiel, Z.; Tercero, B.; Kolesniková, L.; Medvedev, I.R.; López, A.; Fortman, S.; Winnewisser, M.; de Lucia, F. C.; Alonso, J. L.; Guillemin, J.-C.

    2016-01-01

    The recent analysis of the composition of the frozen surface of comet 67P/Churyumov-Gerasimenko has revealed a significant number of complex organic molecules. Methyl isocyanate (CH3NCO) is one of the more abundant species detected on the comet surface. In this work we report extensive characterization of its rotational spectrum resulting in a list of 1269 confidently assigned laboratory lines and its detection in space towards the Orion clouds where 399 lines of the molecule have been unambiguously identified. We find that the limited mm-wave laboratory data reported prior to our work require some revision. The abundance of CH3NCO in Orion is only a factor of ten below those of HNCO and CH3CN. Unlike the molecular abundances in the coma of comets, which correlate with those of warm molecular clouds, molecular abundances in the gas phase in Orion are only weakly correlated with those measured on the comet surface. We also compare our abundances with those derived recently for this molecule towards Sgr B2 (Halfen et al. 2015). A more accurate abundance of CH3NCO is provided for this cloud based on our extensive laboratory work. PMID:27274565

  17. ChIPpeakAnno: a Bioconductor package to annotate ChIP-seq and ChIP-chip data

    PubMed Central

    2010-01-01

    Background Chromatin immunoprecipitation (ChIP) followed by high-throughput sequencing (ChIP-seq) or ChIP followed by genome tiling array analysis (ChIP-chip) have become standard technologies for genome-wide identification of DNA-binding protein target sites. A number of algorithms have been developed in parallel that allow identification of binding sites from ChIP-seq or ChIP-chip datasets and subsequent visualization in the University of California Santa Cruz (UCSC) Genome Browser as custom annotation tracks. However, summarizing these tracks can be a daunting task, particularly if there are a large number of binding sites or the binding sites are distributed widely across the genome. Results We have developed ChIPpeakAnno as a Bioconductor package within the statistical programming environment R to facilitate batch annotation of enriched peaks identified from ChIP-seq, ChIP-chip, cap analysis of gene expression (CAGE) or any experiments resulting in a large number of enriched genomic regions. The binding sites annotated with ChIPpeakAnno can be viewed easily as a table, a pie chart or plotted in histogram form, i.e., the distribution of distances to the nearest genes for each set of peaks. In addition, we have implemented functionalities for determining the significance of overlap between replicates or binding sites among transcription factors within a complex, and for drawing Venn diagrams to visualize the extent of the overlap between replicates. Furthermore, the package includes functionalities to retrieve sequences flanking putative binding sites for PCR amplification, cloning, or motif discovery, and to identify Gene Ontology (GO) terms associated with adjacent genes. Conclusions ChIPpeakAnno enables batch annotation of the binding sites identified from ChIP-seq, ChIP-chip, CAGE or any technology that results in a large number of enriched genomic regions within the statistical programming environment R. Allowing users to pass their own annotation data such

  18. Chemistry Rocks: Redox Chemistry as a Geologic Tool.

    ERIC Educational Resources Information Center

    Burns, Mary Sue

    2001-01-01

    Applies chemistry to earth science, uses rocks in chemistry laboratories, and teaches about transition metal chemistry, oxidation states, and oxidation-reduction reactions from firsthand experiences. (YDS)

  19. Selenium carboxylic acids betaine; 3,3‧,3″-selenotris(propanoic acid) betaine, Se(CH2CH2COOH)2(CH2CH2COO)

    NASA Astrophysics Data System (ADS)

    Doudin, Khalid; Törnroos, Karl W.

    2017-06-01

    Attempts to prepare [Se(CH2CH2COOH)3]+Cl- from Se(CH2CH2COOH)2 and H2Cdbnd CHCOOH in concentrated hydrochloric acid, for the corresponding sulfonium salt, led exclusively to the Se-betaine, Se(CH2CH2COOH)2(CH2CH2COO). The Se-betaine crystallises in the space group P2l/c with the cell dimensions at 223 K, a = 5.5717(1), b = 24.6358(4), c = 8.4361(1) Å, β = 104.762(1)°, V = 1119.74(3) Å3, Z = 4, Dcalc = 1.763 Mgm- 3, μ = 3.364 Mm-1. The structure refined to RI = 0.0223 for 2801 reflections with Fo > 4σ(Fo). In the crystalline state the molecule is intermolecularly linked to neighbouring molecules by a number of hydrogen bonds; a very strong carboxylic-carboxylate bond with an O⋯O distance of 2.4435(16) Å, a medium strong carboxylic-carboxylate bond with an O⋯O distance of 2.6431(16) Å and several weak O⋯H(CH2) with O⋯C distances between 3.2 and 3.3 Å. In the carboxylic group involved in the very strong hydrogen bond the O⋯H bond is antiperiplanar to the Cdbnd O bond while the Osbnd H bond is periplanar to the Cdbnd O bond in the second carboxylic group. Based upon the Csbnd O bond lengths and the elongation of the Osbnd H bond involved in the strong hydrogen bond one may describe the compound as strongly linked units of Se(CH2CH2COOH)(CH2CH2COO)2 rather than Se(CH2CH2COOH)2(CH2CH2COO). The selenium atom forms two strong intramolecular 1,5-Se⋯O contacts, with a carboxylate oxygen atom, 2.9385(12) Å, and with a carboxylic oxygen atom, 2.8979(11) Å. To allow for these contacts the two organic fragments have been forced into the periplanar conformation. The molecule is only slightly asymmetric with regard to the Csbnd Sesbnd C bond angles but is very asymmetric with regard to the torsion angles.

  20. Emergent nanoscale fluctuations in high rock-salt PbTe

    NASA Astrophysics Data System (ADS)

    Billinge, Simon

    2013-03-01

    describe the results of these experiments. This work gives key insights into PbTe, the possible origin of its anomalous electronic structure properties, and why it is such an attractive parent compound for nanostructured high performance thermoelectric materials. I would like to acknowledge the excellent collaborations that occurred during this work, including Emil Bozin at Brookhaven National Laboratory, Mercouri Kanatzidis and Christos Malliakas at Northwestern University and Argonne National Laboratory, Kirsten Jensen from U. Aarhus, Steve Shapiro at Brookhaven National Laboratory, Matt Stone and Mark Lumsden at Oak Ridge National Laboratory, Nicola Spalding at ETH Zurich and Petros Souvatzis at Los Alamos National Laboratory. I would also like to acknowledge the support of the national user facilities and their staff where the work was done. Financial support for this work was from DOE office of Basic Energy Sciences through award DE-AC02-98CH10886.

  1. The Relative Abundances of Resolved 12CH2D2 and 13CH3D and Mechanisms Controlling Isotopic Bond Ordering in Abiotic and Biotic Methane Gases

    NASA Astrophysics Data System (ADS)

    Young, E. D.; Kohl, I. E.; Sherwood Lollar, B.; Etiope, G.; Rumble, D.; Li, S.; Haghnegahdar, M. A.; Schauble, E. A.; McCain, K.; Foustoukos, D.; Sutcliffe, C. N.; Warr, O.; Ballentine, C. J.; Onstott, T. C.; Hosgormez, H.; Neubeck, A.; Marques, J. M.; Perez-Rodriguez, I. M.; Rowe, A. R.; LaRowe, D.; Magnabosco, C.; Bryndzia, T.

    2016-12-01

    We report measurements of resolved 12CH2D2 and 13CH3D at natural abundances in a variety of methane gases produced naturally and in the laboratory. The ability to resolve 12CH2D2 from 13CH3D provides unprecedented insights into the origin and evolution of CH4. The results identify conditions under which either isotopic bond order disequilibrium or equilibrium are expected. Where equilibrium obtains, concordant Δ12CH2D2 and Δ13CH3D temperatures can be used reliably for thermometry. We find that concordant temperatures do not always match previous hypotheses based on indirect estimates of temperature of formation nor temperatures derived from CH4/H2 D/H exchange, underscoring the importance of reliable thermometry based on the CH4 molecules themselves. Where Δ12CH2D2 and Δ13CH3D values are inconsistent with thermodynamic equilibrium, temperatures of formation derived from these species are spurious. In such situations, while formation temperatures are unavailable, disequilibrium isotopologue ratios nonetheless provide important information about the formation mechanism of the gas and the presence or absence of multiple sources or sinks. In particular, disequilibrium isotopologue ratios may provide the means for differentiating between methane produced by abiotic synthesis versus biological processes. Deficits in 12CH2D2 compared with equilibrium values in CH4 gas made by surface-catalyzed abiotic reactions are so large as to point towards a quantum tunneling origin. Tunneling also accounts for the more moderate depletions in 13CH3D that accompany the low 12CH2D2 abundances produced by abiotic reactions. The tunneling signature of abiotic CH4 formation may prove to be an important tracer of abiotic methane formation, especially where it is preserved by dissolution of gas in cool hydrothermal systems (e.g., Mars). Isotopologue signatures of abiotic methane production can be erased by infiltration of microbial communities, and Δ12CH2D2 values are a key tracer of

  2. Electrical and magnetic properties of rock and soil

    USGS Publications Warehouse

    Scott, J.H.

    1983-01-01

    Field and laboratory measurements have been made to determine the electrical conductivity, dielectric constant, and magnetic permeability of rock and soil in areas of interest in studies of electromagnetic pulse propagation. Conductivity is determined by making field measurements of apparent resisitivity at very low frequencies (0-20 cps), and interpreting the true resistivity of layers at various depths by curve-matching methods. Interpreted resistivity values are converted to corresponding conductivity values which are assumed to be applicable at 10^2 cps, an assumption which is considered valid because the conductivity of rock and soil is nearly constant at frequencies below 10^2 cps. Conductivity is estimated at higher frequencies (up to 10^6 cps) by using statistical correlations of three parameters obtained from laboratory measurements of rock and soil samples: conductivity at 10^2 cps, frequency and conductivity measured over the range 10^2 to 10^6 cps. Conductivity may also be estimated in this frequency range by using field measurements of water content and correlations of laboratory sample measurements of the three parameters: water content, frequency, and conductivity measured over the range 10^2 to 10^6 cps. This method is less accurate because nonrandom variation of ion concentration in natural pore water introduces error. Dielectric constant is estimated in a similar manner from field-derived conductivity values applicable at 10^2 cps and statistical correlations of three parameters obtained from laboratory measurements of samples: conductivity measured at 10^2 cps, frequency, and dielectric constant measured over the frequency range 10^2 to 10^6 cps. Dielectric constant may also be estimated from field measurements of water content and correlations of laboratory sample measurements of the three parameters: water content, frequency, and dielectric constant measured from 10^2 to 10^6 cps, but again, this method is less accurate because of variation of

  3. Astronaut David Scott - Sample - "Genesis Rock" - MSC

    NASA Image and Video Library

    1971-08-12

    S71-43477 (12 Aug. 1971) --- Astronaut David R. Scott, right, commander of the Apollo 15 mission, gets a close look at the sample referred to as "Genesis rock" in the Non-Sterile Nitrogen Processing Line (NNPL) in the Lunar Receiving Laboratory (LRL) at the Manned Spacecraft Center (MSC). Scientist-astronaut Joseph P. Allen IV, left, an Apollo 15 spacecraft communicator, looks on with interest. The white-colored rock has been given the permanent identification of 15415.

  4. Location-Related Differences in Weathering Behaviors and Populations of Culturable Rock-Weathering Bacteria Along a Hillside of a Rock Mountain.

    PubMed

    Wang, Qi; Wang, Rongrong; He, Linyan; Sheng, Xiafang

    2017-05-01

    Bacteria play important roles in rock weathering, elemental cycling, and soil formation. However, little is known about the weathering potential and population of bacteria inhabiting surfaces of rocks. In this study, we isolated bacteria from the top, middle, and bottom rock samples along a hillside of a rock (trachyte) mountain as well as adjacent soils and characterized rock-weathering behaviors and populations of the bacteria. Per gram of rock or surface soil, 10 6 -10 7 colony forming units were obtained and total 192 bacteria were isolated. Laboratory rock dissolution experiments indicated that the proportions of the highly effective Fe (ranging from 67 to 92 %), Al (ranging from 40 to 48 %), and Cu (ranging from 54 to 81 %) solubilizers were significantly higher in the top rock and soil samples, while the proportion of the highly effective Si (56 %) solubilizers was significantly higher in the middle rock samples. Furthermore, 78, 96, and 6 % of bacteria from the top rocks, soils, and middle rocks, respectively, significantly acidified the culture medium (pH < 4.0) in the rock dissolution process. Most rock-weathering bacteria (79 %) from the rocks were different to those from the soils and most of them (species level) have not been previously reported. Furthermore, location-specific rock-weathering bacterial populations were found and Bacillus species were the most (66 %) frequently isolated rock-weathering bacteria in the rocks based on cultivation methods. Notably, the top rocks and soils had the highest and lowest diversity of rock-weathering bacterial populations, respectively. The results suggested location-related differences in element (Si, Al, Fe, and Cu) releasing effectiveness and communities of rock-weathering bacteria along the hillside of the rock mountain.

  5. New Rock-Drilling Method in 'Mars Yard' Test

    NASA Image and Video Library

    2017-10-23

    This photo taken in the "Mars Yard" at NASA's Jet Propulsion Laboratory, Pasadena, California, on Aug. 1, 2017, shows a step in development of possible alternative techniques that NASA's Curiosity Mars rover might be able to use to resume drilling into rocks on Mars. In late 2016, after Curiosity's drill had collected sample material from 15 Martian rocks in four years, the drill's feed mechanism ceased working reliably. That motorized mechanism moved the bit forward or back with relation to stabilizer posts on either side of the bit. In normal drilling by Curiosity, the stabilizers were positioned on the target rock first, and then the feed mechanism extended the rotation-percussion bit into the rock. In the alternative technique seen here, called "feed-extended drilling," the test rover's stabilizers are not used to touch the rock. The bit is advanced into the rock by motion of the robotic arm rather than the drill's feed mechanism. https://photojournal.jpl.nasa.gov/catalog/PIA22062

  6. libChEBI: an API for accessing the ChEBI database.

    PubMed

    Swainston, Neil; Hastings, Janna; Dekker, Adriano; Muthukrishnan, Venkatesh; May, John; Steinbeck, Christoph; Mendes, Pedro

    2016-01-01

    ChEBI is a database and ontology of chemical entities of biological interest. It is widely used as a source of identifiers to facilitate unambiguous reference to chemical entities within biological models, databases, ontologies and literature. ChEBI contains a wealth of chemical data, covering over 46,500 distinct chemical entities, and related data such as chemical formula, charge, molecular mass, structure, synonyms and links to external databases. Furthermore, ChEBI is an ontology, and thus provides meaningful links between chemical entities. Unlike many other resources, ChEBI is fully human-curated, providing a reliable, non-redundant collection of chemical entities and related data. While ChEBI is supported by a web service for programmatic access and a number of download files, it does not have an API library to facilitate the use of ChEBI and its data in cheminformatics software. To provide this missing functionality, libChEBI, a comprehensive API library for accessing ChEBI data, is introduced. libChEBI is available in Java, Python and MATLAB versions from http://github.com/libChEBI, and provides full programmatic access to all data held within the ChEBI database through a simple and documented API. libChEBI is reliant upon the (automated) download and regular update of flat files that are held locally. As such, libChEBI can be embedded in both on- and off-line software applications. libChEBI allows better support of ChEBI and its data in the development of new cheminformatics software. Covering three key programming languages, it allows for the entirety of the ChEBI database to be accessed easily and quickly through a simple API. All code is open access and freely available.

  7. Direct laboratory observation of fluid distribution and its influence on acoustic properties of patchy saturated rocks

    NASA Astrophysics Data System (ADS)

    Lebedev, M.; Clennell, B.; Pervukhina, M.; Shulakova, V.; Mueller, T.; Gurevich, B.

    2009-04-01

    samples (38 mm in diameter, approximately 60 mm long) were dried in oven under reduced pressure. In dynamic saturation experiments, samples were jacketed in the experimental cell, made from transparent for X-radiation material (PMMA). Distillate water was injected into the sample from the one side. Fluid distribution in such "dynamic" experiment: both spatial and time dependant was measured using X-ray Computer Tomograph (CT) with resolution 0.2 x 0.2 x 1 mm3. Velocities (Vp, and Vs) at ultrasonic frequency of 1 MHz, were measured in the direction perpendicular to initial direction of the fluid flow injection. Sample saturation was estimated from the CT results. In "quasi static" experiments samples were saturated during long period of time (over 2 weeks) to achieve uniform distribution of liquid inside the sample. Saturation was determined by measurement of the weight of water fraction. All experiments were performed at laboratory environments at temperature 25 C. Ultrasonic velocities and fluid saturations were measured simultaneously during water injection into sandstone core samples. The experimental results obtained on low-permeability samples show that at low saturation values the velocity-saturation dependence can be described by the Gassmann-Wood relationship. However, with increasing saturation a sharp increase of P-wave velocity is observed, eventually approaching the Gassmann-Hill relationship. We connect the characteristics of the transition behavior of the velocity-saturation relationships to the increasing size of the patches inside the rock sample. In particular, we show that for relatively large fluid injection rate this transition occurs at smaller degrees of saturation as compared with high injection rate. We model the experimental data using the so-called White model (Toms 2007) that assumes fluid patch distribution as a periodic assemblage of concentric spheres. We can observe reasonable agreement between experimental results and theoretical

  8. Unboxing Space Rocks

    ScienceCinema

    Bruck Syal, Megan

    2018-01-16

    The box was inconspicuous, but Lawrence Livermore National Laboratory (LLNL) postdoctoral researcher Megan Bruck Syal immediately knew its contents: two meteorites around the size of walnuts. They formed about 4.6 billion years ago and survived a history of violent collisions in the asteroid belt before being bumped into a near-Earth-object orbit by gravitational interactions with the planets. After finally raining down on Earth, these rocks were scavenged in Antarctica by researchers, sorted and classified at NASA Johnson Space Center, then mailed first-class to Bruck Syal. Now that these space rocks are in Bruck Syal’s hands, they are mere months away from fulfilling their destiny. They are to be vaporized by a high-powered laser, and the data they yield on asteroid deflection could one day save the planet.

  9. Unboxing Space Rocks

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bruck Syal, Megan

    The box was inconspicuous, but Lawrence Livermore National Laboratory (LLNL) postdoctoral researcher Megan Bruck Syal immediately knew its contents: two meteorites around the size of walnuts. They formed about 4.6 billion years ago and survived a history of violent collisions in the asteroid belt before being bumped into a near-Earth-object orbit by gravitational interactions with the planets. After finally raining down on Earth, these rocks were scavenged in Antarctica by researchers, sorted and classified at NASA Johnson Space Center, then mailed first-class to Bruck Syal. Now that these space rocks are in Bruck Syal’s hands, they are mere months awaymore » from fulfilling their destiny. They are to be vaporized by a high-powered laser, and the data they yield on asteroid deflection could one day save the planet.« less

  10. Do Bare Rocks Exist on the Moon?

    NASA Technical Reports Server (NTRS)

    Allen, Carlton; Bandfield, Joshua; Greenhagen, Benjamin; Hayne, Paul; Leader, Frank; Paige, David

    2017-01-01

    Astronaut surface observations and close-up images at the Apollo and Chang'e 1 landing sites confirm that at least some lunar rocks have no discernable dust cover. However, ALSEP (Apollo Lunar Surface Experiments Package) measurements as well as astronaut and LADEE (Lunar Atmosphere and Dust Environment Explorer) orbital observations and laboratory experiments possibly suggest that a fine fraction of dust is levitated and moves across and above the lunar surface. Over millions of years such dust might be expected to coat all exposed rock surfaces. This study uses thermal modeling, combined with Diviner (a Lunar Reconnaissance Orbiter experiment) orbital lunar eclipse temperature data, to further document the existence of bare rocks on the lunar surface.

  11. Analyses of rocks and minerals from the laboratory of the United States Geological Survey, 1880 to 1914

    USGS Publications Warehouse

    Clarke, Frank Wigglesworth

    1915-01-01

    The present Geological Survey of the United States was organized in 1879. In 1880, in connection with the Colorado work, a chemical laboratory was established at Denver in charge of W. F. Hillebrand, with whom were associated Antony Guyard and, later, L. G. Eakins. In 1882 W. H. Melville was placed in charge of a second laboratory at San Francisco, and in the autumn of 1883 the central laboratory was started in Washington, with myself as chief chemist. In November, 1885, Dr. Hillebrand was transferred to Washington; early in 1888 he was followed by Mr. Eakins, and the Denver laboratory was discontinued. In the spring of 1890 Dr. Melville also was transferred to Washington, and since then the geochemical work of the Survey has been concentrated at headquarters. The special laboratories of the water-resources and technologic branches of the Survey are not included in this statement and their work is not represented in this bulletin.Up to January 1, 1914, nearly 8,000 analyses have been made in the laboratory at Washington of rocks, minerals, ores, waters, sediments, coals, metals, and other substances with which geology has to do. Some-hundreds of analyses were also made in the laboratories at Denver and San Francisco. A fair amount of research work upon mineralogical and analytical problems has also been done. In *all of this work the following chemists have been employed: E. T. Allen, R. K. Bailey, Charles Catlett, T. M. Chatard, F. W. Clarke, L. G. Eakins, J. G. Fairchild, F. A. Gooch, Antony Guyard, W. B. Hicks, W. F. Hillebrand, W. F. Hunt, W. H. Melville, H. C. McNeil, Chase Palmer, R. B. Riggs, W. T. Schaller, E. A. Schneider, George Steiger, H. N. Stokes, E. C. Sullivan, William Valentine, R. C. Wells, W. C. Wheeler, and J. E. Whitfield. At present, January 1, 1914, eight of these chemists are employed in the Survey. Other officers of the Survey have been occupied more or less with chemical questions, but the men named in this list were connected directly

  12. The determination of the acoustic parameters of volcanic rocks from compressional velocity measurements

    USGS Publications Warehouse

    Carroll, R.D.

    1969-01-01

    A statistical analysis was made of the relationship of various acoustic parameters of volcanic rocks to compressional wave velocities for data obtained in a volcanic region in Nevada. Some additional samples, chiefly granitic rocks, were also included in the study to extend the range of parameters and the variety of siliceous rock types sampled. Laboratory acoustic measurements obtained on 62 dry core samples were grouped with similar measurements obtained from geophysical logging devices at several depth intervals in a hole from which 15 of the core samples had been obtained. The effects of lithostatic and hydrostatic load on changing the rock acoustic parameters measured in the hole were noticeable when compared with the laboratory measurements on the same core. The results of the analyses determined by grouping all of the data, however, indicate that dynamic Young's, shear and bulk modulus, shear velocity, shear and compressional characteristic impedance, as well as amplitude and energy reflection coefficients may be reliably estimated on the basis of the compressional wave velocities of the rocks investigated. Less precise estimates can be made of density based on the rock compressional velocity. The possible extension of these relationships to include many siliceous rocks is suggested. ?? 1969.

  13. The relative abundances of resolved l2CH2D2 and 13CH3D and mechanisms controlling isotopic bond ordering in abiotic and biotic methane gases

    NASA Astrophysics Data System (ADS)

    Young, E. D.; Kohl, I. E.; Lollar, B. Sherwood; Etiope, G.; Rumble, D.; Li, S.; Haghnegahdar, M. A.; Schauble, E. A.; McCain, K. A.; Foustoukos, D. I.; Sutclife, C.; Warr, O.; Ballentine, C. J.; Onstott, T. C.; Hosgormez, H.; Neubeck, A.; Marques, J. M.; Pérez-Rodríguez, I.; Rowe, A. R.; LaRowe, D. E.; Magnabosco, C.; Yeung, L. Y.; Ash, J. L.; Bryndzia, L. T.

    2017-04-01

    We report measurements of resolved 12CH2D2 and 13CH3D at natural abundances in a variety of methane gases produced naturally and in the laboratory. The ability to resolve 12CH2D2 from 13CH3D provides unprecedented insights into the origin and evolution of CH4. The results identify conditions under which either isotopic bond order disequilibrium or equilibrium are expected. Where equilibrium obtains, concordant Δ12CH2D2 and Δ13CH3D temperatures can be used reliably for thermometry. We find that concordant temperatures do not always match previous hypotheses based on indirect estimates of temperature of formation nor temperatures derived from CH4/H2 D/H exchange, underscoring the importance of reliable thermometry based on the CH4 molecules themselves. Where Δ12CH2D2 and Δ13CH3D values are inconsistent with thermodynamic equilibrium, temperatures of formation derived from these species are spurious. In such situations, while formation temperatures are unavailable, disequilibrium isotopologue ratios nonetheless provide novel information about the formation mechanism of the gas and the presence or absence of multiple sources or sinks. In particular, disequilibrium isotopologue ratios may provide the means for differentiating between methane produced by abiotic synthesis vs. biological processes. Deficits in 12CH2D2 compared with equilibrium values in CH4 gas made by surface-catalyzed abiotic reactions are so large as to point towards a quantum tunneling origin. Tunneling also accounts for the more moderate depletions in 13CH3D that accompany the low 12CH2D2 abundances produced by abiotic reactions. The tunneling signature may prove to be an important tracer of abiotic methane formation, especially where it is preserved by dissolution of gas in cool hydrothermal systems (e.g., Mars). Isotopologue signatures of abiotic methane production can be erased by infiltration of microbial communities, and Δ12CH2D2 values are a key tracer of microbial recycling.

  14. Laboratory Studies on the Formation of Three C2H4O Isomers-Acetaldehyde (CH3CHO), Ethylene Oxide (c-C2H4O), and Vinyl Alcohol (CH2CHOH)-in Interstellar and Cometary Ices

    NASA Astrophysics Data System (ADS)

    Bennett, Chris J.; Osamura, Yoshihiro; Lebar, Matt D.; Kaiser, Ralf I.

    2005-11-01

    Laboratory experiments were conducted to unravel synthetic routes to form three C2H4O isomers-acetaldehyde (CH3CHO), ethylene oxide (c-C2H4O), and vinyl alcohol (CH2CHOH)-in extraterrestrial ices via electronic energy transfer processes initiated by electrons in the track of MeV ion trajectories. Here we present the results of electron irradiation on a 2:1 mixture of carbon dioxide (CO2) and ethylene (C2H4). Our studies suggest that suprathermal oxygen atoms can add to the carbon-carbon π bond of an ethylene molecule to form initially an oxirene diradical (addition to one carbon atom) and the cyclic ethylene oxide molecule (addition to two carbon atoms) at 10 K. The oxirene diradical can undergo a [1, 2]-H shift to the acetaldehyde molecule. Both the ethylene oxide and the acetaldehyde isomers can be stabilized in the surrounding ice matrix. To a minor amount, suprathermal oxygen atoms can insert into a carbon-hydrogen bond of the ethylene molecule, forming vinyl alcohol. Once these isomers have been synthesized inside the ice layers of the coated grains in cold molecular clouds, the newly formed molecules can sublime as the cloud reaches the hot molecular core stage. These laboratory investigations help to explain astronomical observations by Nummelin et al. and Ikeda et al. toward massive star-forming regions and hot cores, where observed fractional abundances of these isomers are higher than can be accounted for by gas-phase reactions alone. Similar synthetic routes could help explain the formation of acetaldehyde and ethylene oxide in comet C/1995 O1 (Hale-Bopp) and also suggest a presence of both isomers in Titan's atmosphere.

  15. Electron Attachment to Halomethanes at High Temperature: CH2CI2, CF2CI2, CH3CI, and CF3CI Attachment Rate Constants up to 1100 K

    DTIC Science & Technology

    2009-08-01

    hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and...attachment reactions: 390i 50 meV (CH:Cl;). 124* 20 meV (CF2CI2), 670 + 70 meV (CH3CI), and 406±50 meV (CF,C1). Comparisons are made with existing data ...Research Laboratory, 29 Randolph Road, Hanscom Air Force Base . Massachusetts 01731-3010, USA (Received 15 May 2009; accepted 4 August 2009; published

  16. Rock Content Influence on Soil Hydraulic Properties

    NASA Astrophysics Data System (ADS)

    Parajuli, K.; Sadeghi, M.; Jones, S. B.

    2015-12-01

    Soil hydraulic properties including the soil water retention curve (SWRC) and hydraulic conductivity function are important characteristics of soil affecting a variety of soil properties and processes. The hydraulic properties are commonly measured for seived soils (i.e. particles < 2 mm), but many natural soils include rock fragments of varying size that alter bulk hydraulic properties. Relatively few studies have addressed this important problem using physically-based concepts. Motivated by this knowledge gap, we set out to describe soil hydraulic properties using binary mixtures (i.e. rock fragment inclusions in a soil matrix) based on individual properties of the rock and soil. As a first step of this study, special attention was devoted to the SWRC, where the impact of rock content on the SWRC was quantified using laboratory experiments for six different mixing ratios of soil matrix and rock. The SWRC for each mixture was obtained from water mass and water potential measurements. The resulting data for the studied mixtures yielded a family of SWRC indicating how the SWRC of the mixture is related to that of the individual media, i.e., soil and rock. A consistent model was also developed to describe the hydraulic properties of the mixture as a function of the individual properties of the rock and soil matrix. Key words: Soil hydraulic properties, rock content, binary mixture, experimental data.

  17. On the Jupiter's ephemeris in the Ch'i-Yao Jang-Tsai-Chüch.

    NASA Astrophysics Data System (ADS)

    Niu, Weixing; Jiang, Xiaoyuan

    Jupiter's ephemeris preserved in the Ch'i-Yao Jang-Tsai-Chüch is interpreted. Then the time and position coordinates of Jupiter's first stationary point, second stationary point, first visibility in the east and last visibility in the west, which recorded in the ephemeris are analysed. The accuracy of the ephemeris is also discussed. Finally, it is identified that the ephemeris has been used as an astrological handbook by Japanese astrologers in 973 - 1132.

  18. Laboratory Characterization of Cemented Rock Fill for Underhand Cut and Fill Method of Mining

    NASA Astrophysics Data System (ADS)

    Kumar, Dinesh; Singh, Upendra Kumar; Singh, Gauri Shankar Prasad

    2016-10-01

    Backfilling with controlled specifications is employed for improved ground support and pillar recovery in underground metalliferous mine workings. This paper reports the results of a laboratory study to characterise various mechanical properties of cemented rock fill (CRF) formulations for different compaction levels and cement content percentage for use in underhand cut and fill method of mining. Laboratory test set ups and procedures have been described for conducting compressive and bending tests of CRF block samples. A three dimensional numerical modelling study has also been carried out to overcome the limitations arising due to non-standard dimension of test blocks used in flexural loading test and the test setup devised for this purpose. Based on these studies, specific relations have been established between the compressive and the flexural properties of the CRF. The flexural strength of the wire mesh reinforced CRF is also correlated with its residual strength and the Young's modulus of elasticity under flexural loading condition. The test results of flexural strength, residual flexural strength and modulus show almost linear relations with cement content in CRF. The compressive strength of the CRF block samples is estimated as seven times the flexural strength whereas the compressive modulus is four times the flexural modulus. It has been found that the strengths of CRF of low compaction and no compaction are 75 and 60 % respectively to that of the medium compaction CRF. The relation between the strength and the unit weight of CRF as obtained in this study is significantly important for design and quality control of CRF during its large scale application in underhand cut and fill stopes.

  19. Rock Moved by Mars Lander Arm

    NASA Technical Reports Server (NTRS)

    2008-01-01

    The robotic arm on NASA's Phoenix Mars Lander slid a rock out of the way during the mission's 117th Martian day (Sept. 22, 2008) to gain access to soil that had been underneath the rock.The lander's Surface Stereo Imager took the two images for this stereo view later the same day, showing the rock, called 'Headless,' after the arm pushed it about 40 centimeters (16 inches) from its previous location.

    'The rock ended up exactly where we intended it to,' said Matt Robinson of NASA's Jet Propulsion Laboratory, robotic arm flight software lead for the Phoenix team.

    The arm had enlarged the trench near Headless two days earlier in preparation for sliding the rock into the trench. The trench was dug to about 3 centimeters (1.2 inches) deep. The ground surface between the rock's prior position and the lip of the trench had a slope of about 3 degrees downward toward the trench. Headless is about the size and shape of a VHS videotape.

    The Phoenix science team sought to move the rock in order to study the soil and the depth to subsurface ice underneath where the rock had been.

    This image was taken at about 12:30 p.m., local solar time on Mars. The view is to the north northeast of the lander.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by JPL, Pasadena, Calif. Spacecraft development was by Lockheed Martin Space Systems, Denver.

  20. Geophysical Evolution of Ch Asteroids and Testable Hypotheses for Future Missions

    NASA Astrophysics Data System (ADS)

    Castillo, J. C.

    2017-12-01

    The main population of asteroids related to meteorites in the collections remains to be explored in situ. Ch asteroids are the only midsized asteroids that display a signature of hydration (besides Pallas) and the spectral connection between Ch asteroids and CM chondrites suggests that the former represent potential parent bodies for the latter. This class of asteroids is particularly interesting because it hosts many objects 100-200 km in size, which are believed to belong to a primordial population of planetesimals. This presentation will explore multiple evolution pathways for Ch-asteroids leading to possible hypotheses on the geological, petrological, and geophysical properties that a disrupted parent body would present to a future mission. This work is being carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract to NASA.

  1. Positive Holes Flowing through Stressed Igneous Rocks

    NASA Astrophysics Data System (ADS)

    Takeuchi, Akihiro

    Igneous rocks generally involve positive hole pairs (PHPs), a kind of lattice defects also known as peroxy links: O3X-OO-YO3 with X, Y = Si4+, Al3+ etc. When a portion of such a rock block is stressed or heated, PHPs are deformed and positive holes (p-holes) are activated. They are defect electrons corresponding to the O- electronic state in the O2- sublattice and can spread away into unstressed portion. Currents and positive surface electrifications detected in laboratory stressed igneous rocks can be explained by the p-holes. When the p-holes are activated in the Earth's crust accompanied with seismic or volcanic events, they would lead to anomalous electromagnetic phenomena and could affect our electronic communication.

  2. Experimental investigations and geochemical modelling of site-specific fluid-fluid and fluid-rock interactions in underground storage of CO2/H2/CH4 mixtures: the H2STORE project

    NASA Astrophysics Data System (ADS)

    De Lucia, Marco; Pilz, Peter

    2015-04-01

    work packages hosted at the German Research Centre for Geosciences (GFZ) focus on the fluid-fluid and fluid-rock interactions triggered by CO2, H2 and their mixtures. Laboratory experiments expose core samples to hydrogen and CO2/hydrogen mixtures under site-specific conditions (temperatures up to 200 °C and pressure up to 300 bar). The resulting qualitative and, whereas possible, quantitative data are expected to ameliorate the precision of predictive geochemical and reactive transport modelling, which is also performed within the project. The combination of experiments, chemical and mineralogical analyses and models is needed to improve the knowledge about: (1) solubility model and mixing rule for multicomponent gas mixtures in high saline formation fluids: no data are namely available in literature for H2-charged gas mixtures in the conditions expected in the potential sites; (2) chemical reactivity of different mineral assemblages and formation fluids in a broad spectrum of P-T conditions and composition of the stored gas mixtures; (3) thermodynamics and kinetics of relevant reactions involving mineral dissolution or precipitation. The resulting amelioration of site characterization and the overall enhancement in understanding the potential processes will benefit the operational reliability, the ecological tolerance, and the economic efficiency of future energy storing plants, crucial aspects for public acceptance and for industrial investors.

  3. Relative scale and the strength and deformability of rock masses

    NASA Astrophysics Data System (ADS)

    Schultz, Richard A.

    1996-09-01

    The strength and deformation of rocks depend strongly on the degree of fracturing, which can be assessed in the field and related systematically to these properties. Appropriate Mohr envelopes obtained from the Rock Mass Rating (RMR) classification system and the Hoek-Brown criterion for outcrops and other large-scale exposures of fractured rocks show that rock-mass cohesive strength, tensile strength, and unconfined compressive strength can be reduced by as much as a factor often relative to values for the unfractured material. The rock-mass deformation modulus is also reduced relative to Young's modulus. A "cook-book" example illustrates the use of RMR in field applications. The smaller values of rock-mass strength and deformability imply that there is a particular scale of observation whose identification is critical to applying laboratory measurements and associated failure criteria to geologic structures.

  4. Determining the Accuracy of Paleomagnetic Remanence and High-Resolution Chronostratigraphy for Sedimentary Rocks using Rock Magnetics

    NASA Astrophysics Data System (ADS)

    Kodama, K. P.

    2017-12-01

    The talk will consider two broad topics in rock magnetism and paleomagnetism: the accuracy of paleomagnetic remanence and the use of rock magnetics to measure geologic time in sedimentary sequences. The accuracy of the inclination recorded by sedimentary rocks is crucial to paleogeographic reconstructions. Laboratory compaction experiments show that inclination shallows on the order of 10˚-15˚. Corrections to the inclination can be made using the effects of compaction on the directional distribution of secular variation recorded by sediments or the anisotropy of the magnetic grains carrying the ancient remanence. A summary of all the compaction correction studies as of 2012 shows that 85% of sedimentary rocks studied have enjoyed some amount of inclination shallowing. Future work should also consider the effect of grain-scale strain on paleomagnetic remanence. High resolution chronostratigraphy can be assigned to a sedimentary sequence using rock magnetics to detect astronomically-forced climate cycles. The power of the technique is relatively quick, non-destructive measurements, the objective identification of the cycles compared to facies interpretations, and the sensitivity of rock magnetics to subtle changes in sedimentary source. An example of this technique comes from using rock magnetics to identify astronomically-forced climate cycles in three globally distributed occurrences of the Shuram carbon isotope excursion. The Shuram excursion may record the oxidation of the world ocean in the Ediacaran, just before the Cambrian explosion of metazoans. Using rock magnetic cyclostratigraphy, the excursion is shown to have the same duration (8-9 Myr) in southern California, south China and south Australia. Magnetostratigraphy of the rocks carrying the excursion in California and Australia shows a reversed to normal geomagnetic field polarity transition at the excursion's nadir, thus supporting the synchroneity of the excursion globally. Both results point to a

  5. Pore water colloid properties in argillaceous sedimentary rocks.

    PubMed

    Degueldre, Claude; Cloet, Veerle

    2016-11-01

    The focus of this work is to evaluate the colloid nature, concentration and size distribution in the pore water of Opalinus Clay and other sedimentary host rocks identified for a potential radioactive waste repository in Switzerland. Because colloids could not be measured in representative undisturbed porewater of these host rocks, predictive modelling based on data from field and laboratory studies is applied. This approach allowed estimating the nature, concentration and size distributions of the colloids in the pore water of these host rocks. As a result of field campaigns, groundwater colloid concentrations are investigated on the basis of their size distribution quantified experimentally using single particle counting techniques. The colloid properties are estimated considering data gained from analogue hydrogeochemical systems ranging from mylonite features in crystalline fissures to sedimentary formations. The colloid concentrations were analysed as a function of the alkaline and alkaline earth element concentrations. Laboratory batch results on clay colloid generation from compacted pellets in quasi-stagnant water are also reported. Experiments with colloids in batch containers indicate that the size distribution of a colloidal suspension evolves toward a common particle size distribution independently of initial conditions. The final suspension size distribution was found to be a function of the attachment factor of the colloids. Finally, calculations were performed using a novel colloid distribution model based on colloid generation, aggregation and sedimentation rates to predict under in-situ conditions what makes colloid concentrations and size distributions batch- or fracture-size dependent. The data presented so far are compared with the field and laboratory data. The colloid occurrence, stability and mobility have been evaluated for the water of the considered potential host rocks. In the pore water of the considered sedimentary host rocks, the clay

  6. Rate constants for the reactions of OH with CH3Cl, CH2Cl2, CHCl3, and CH3Br

    NASA Technical Reports Server (NTRS)

    Hsu, K.-J.; Demore, W. B.

    1994-01-01

    Rate constants for the reactions of OH with CH3Cl, CH2Cl2, CHCl3, and CH3Br have been measured by a relative rate technique in which the reaction rate of each compound was compared to that of HFC-152a (CH3CHF2) and (for CH2Cl2) HFC-161 (CH3CH2F). Using absolute rate constants for HFC-152a and HFC-161, which we have determined relative to those for CH4, CH3CCl3, and C2H6, temperature dependent rate constants of both compounds were derived. The derived rate constant for CH3Br is in good agreement with recent absolute measurements. However, for the chloromethanes all the rate constants are lower at atmospheric temperatures than previously reported, especially for CH2Cl2 where the present rate constant is about a factor of 1.6 below the JPL 92-20 value. The new rate constant appears to resolve a discrepancy between the observed atmospheric concentrations and those calculated from the previous rate constant and estimated release rates.

  7. Characterization of rock samples and mineralogical controls on leachates

    USGS Publications Warehouse

    Hammarstrom, Jane M.; Cravotta, Charles A.; Galeone, Daniel G.; Jackson, John C.; Dulong, Frank T.; Hornberger, Roger J.; Brady, Keith B.C.

    2009-01-01

    Rocks associated with coal beds typically include shale, sandstone, and (or) limestone. In addition to common rock-forming minerals, all of these rock types may contain sulfide and sulfate minerals, various carbonate minerals, and organic material. These different minerals have inherently different solubility characteristics, as well as different acid-generating or acid-neutralizing potentials. The abundance and composition of sulfur- and carbonate-bearing minerals are of particular interest in interpreting the leaching column data because (1) pyrite and carbonate minerals are the primary controls on the acid-base account of a sample, (2) these minerals incorporate trace metals that can be released during weathering, and (3) these minerals readily react during weathering due to mineral dissolution and oxidation of iron.Rock samples were collected by the Pennsylvania Department of Environmental Protection (PaDEP) from five different sites to assess the draft standardized leaching column method (ADTI-WP2) for the prediction of weathering rates and water quality at coal mines. Samples were sent to USGS laboratories for mineralogical characterization and to ActLabs for chemical analysis. The samples represent a variety of rock types (shales, sandstones, and coal refuse) that are typical of coal overburden in the eastern United States. These particular samples were chosen for testing the weathering protocols because they represent a range of geochemical and lithologic characteristics, sulfur contents, and acid-base accounting characteristics (Hornberger et al., 2003). The rocks contain variable amounts of pyrite and carbonate minerals and vary in texture.This chapter includes bulk rock chemical data and detailed mineralogical and textural data for unweathered starting materials used in the interlaboratory validation study, and for two samples used in the early phases of leaching column tests (Wadesville Sandstone, Leechburg Coal Refuse). We also characterize some of the

  8. Comparison of Crack Initiation, Propagation and Coalescence Behavior of Concrete and Rock Materials

    NASA Astrophysics Data System (ADS)

    Zengin, Enes; Abiddin Erguler, Zeynal

    2017-04-01

    There are many previously studies carried out to identify crack initiation, propagation and coalescence behavior of different type of rocks. Most of these studies aimed to understand and predict the probable instabilities on different engineering structures such as mining galleries or tunnels. For this purpose, in these studies relatively smaller natural rock and synthetic rock-like models were prepared and then the required laboratory tests were performed to obtain their strength parameters. By using results provided from these models, researchers predicted the rock mass behavior under different conditions. However, in the most of these studies, rock materials and models were considered as contains none or very few discontinuities and structural flaws. It is well known that rock masses naturally are extremely complex with respect to their discontinuities conditions and thus it is sometimes very difficult to understand and model their physical and mechanical behavior. In addition, some vuggy rock materials such as basalts and limestones also contain voids and gaps having various geometric properties. Providing that the failure behavior of these type of rocks controlled by the crack initiation, propagation and coalescence formed from their natural voids and gaps, the effect of these voids and gaps over failure behavior of rocks should be investigated. Intact rocks are generally preferred due to relatively easy side of their homogeneous characteristics in numerical modelling phases. However, it is very hard to extract intact samples from vuggy rocks because of their complex pore sizes and distributions. In this study, the feasibility of concrete samples to model and mimic the failure behavior vuggy rocks was investigated. For this purpose, concrete samples were prepared at a mixture of %65 cement dust and %35 water and their physical and mechanical properties were determined by laboratory experiments. The obtained physical and mechanical properties were used to

  9. Changes in geophysical properties caused by fluid injection into porous rocks: analytical models: Geophysical changes in porous rocks

    DOE PAGES

    Pride, Steven R.; Berryman, James G.; Commer, Michael; ...

    2016-08-30

    Analytical models are provided that describe how the elastic compliance, electrical conductivity, and fluid-flow permeability of rocks depend on stress and fluid pressure. In order to explain published laboratory data on how seismic velocities and electrical conductivity vary in sandstones and granites, the models require a population of cracks to be present in a possibly porous host phase. The central objective is to obtain a consistent mean-field analytical model that shows how each modeled rock property depends on the nature of the crack population. We describe the crack populations by a crack density, a probability distribution for the crack aperturesmore » and radii, and the averaged orientation of the cracks. The possibly anisotropic nature of the elasticity, conductivity, and permeability tensors is allowed for; however, only the isotropic limit is used when comparing to laboratory data. For the transport properties of conductivity and permeability, the percolation effect of the crack population linking up to form a connected path across a sample is modeled. But, this effect is important only in crystalline rock where the host phase has very small conductivity and permeability. In general, the importance of the crack population to the transport properties increases as the host phase becomes less conductive and less permeable.« less

  10. Changes in geophysical properties caused by fluid injection into porous rocks: analytical models: Geophysical changes in porous rocks

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Pride, Steven R.; Berryman, James G.; Commer, Michael

    Analytical models are provided that describe how the elastic compliance, electrical conductivity, and fluid-flow permeability of rocks depend on stress and fluid pressure. In order to explain published laboratory data on how seismic velocities and electrical conductivity vary in sandstones and granites, the models require a population of cracks to be present in a possibly porous host phase. The central objective is to obtain a consistent mean-field analytical model that shows how each modeled rock property depends on the nature of the crack population. We describe the crack populations by a crack density, a probability distribution for the crack aperturesmore » and radii, and the averaged orientation of the cracks. The possibly anisotropic nature of the elasticity, conductivity, and permeability tensors is allowed for; however, only the isotropic limit is used when comparing to laboratory data. For the transport properties of conductivity and permeability, the percolation effect of the crack population linking up to form a connected path across a sample is modeled. But, this effect is important only in crystalline rock where the host phase has very small conductivity and permeability. In general, the importance of the crack population to the transport properties increases as the host phase becomes less conductive and less permeable.« less

  11. Accounting for immunoprecipitation efficiencies in the statistical analysis of ChIP-seq data.

    PubMed

    Bao, Yanchun; Vinciotti, Veronica; Wit, Ernst; 't Hoen, Peter A C

    2013-05-30

    ImmunoPrecipitation (IP) efficiencies may vary largely between different antibodies and between repeated experiments with the same antibody. These differences have a large impact on the quality of ChIP-seq data: a more efficient experiment will necessarily lead to a higher signal to background ratio, and therefore to an apparent larger number of enriched regions, compared to a less efficient experiment. In this paper, we show how IP efficiencies can be explicitly accounted for in the joint statistical modelling of ChIP-seq data. We fit a latent mixture model to eight experiments on two proteins, from two laboratories where different antibodies are used for the two proteins. We use the model parameters to estimate the efficiencies of individual experiments, and find that these are clearly different for the different laboratories, and amongst technical replicates from the same lab. When we account for ChIP efficiency, we find more regions bound in the more efficient experiments than in the less efficient ones, at the same false discovery rate. A priori knowledge of the same number of binding sites across experiments can also be included in the model for a more robust detection of differentially bound regions among two different proteins. We propose a statistical model for the detection of enriched and differentially bound regions from multiple ChIP-seq data sets. The framework that we present accounts explicitly for IP efficiencies in ChIP-seq data, and allows to model jointly, rather than individually, replicates and experiments from different proteins, leading to more robust biological conclusions.

  12. The Rock that Hit New York

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Meade, Roger Allen; Keksis, August Lawrence

    On January 12, 1975, a rock seemed to fall from the sky over New York State’s Schoharie County hitting the tractor of a local farmer, who was “preparing his fields for spring planting.” As the farmer later described the event to a reporter from the UFO INVESTIGATOR, the object glanced off the tractor, fell to the ground, and melted its way through a patch of ice that was two and one half inches thick. The farmer, Leonard Tillapaugh, called the county sheriff, Harvey Stoddard, who recovered the rock, noting that it “was still warm.” Why and how a sample ofmore » the rock came to Los Alamos is not known. However, it captivated a wide Laboratory audience, was subjected to rigorous testing and evaluation. Los Alamos used the scientific method in the manner promoted by Hynek. Did Los Alamos solve the mystery of the rock’s origin? Not definitively. Although the exact origin could not be determined, it was shown conclusively that the rock was not from outer space. With that said, the saga of Rock that hit New York came to an end. Nothing more was said or written about it. The principals involved have long since passed from the scene. The NICAP ceased operations in 1980. And, the rock, itself, has disappeared.« less

  13. Rock Magnetism: Successes and Mysteries

    NASA Astrophysics Data System (ADS)

    Dunlop, D. J.

    2011-12-01

    governs a rock's induced response to weak fields like the Earth's. In particular, the Hopkinson peak in susceptibility near the Curie temperature - a potential source of "missing magnetism" in the deep lithosphere - increases steadily over at least a decade of decreasing grain size in magnetite. Single-domain recorders, in addition to their strong and long-lasting memory, have the property of TRM additivity and independence. This makes possible the Thellier method of determining paleofield intensity, a much more demanding undertaking than tracking paleomagnetic field directions, in which the ancient magnetic moment is gradually replaced by a set of partial TRMs produced in a known laboratory field. Partial TRMs produced in nature by heating during deep burial are also additive and independent. The temperature at which these overprints are removed in the laboratory yields - after correction for the very different natural and laboratory heating times - the burial temperature. This is the basis of magnetic paleothermometry. The interplay of time and temperature in TRM when combined with thermal history models provides estimates of when the global magnetic field of a planet, e.g., Mars, was born and died. But the grand conclusions so important to geophysics rest ultimately on the fidelity of the microscopic recorders in rocks and here, despite many advances, our understanding is still a work in progress.

  14. Environmental characterisation of coal mine waste rock in the field: an example from New Zealand

    NASA Astrophysics Data System (ADS)

    Hughes, J.; Craw, D.; Peake, B.; Lindsay, P.; Weber, P.

    2007-08-01

    Characterisation of mine waste rock with respect to acid generation potential is a necessary part of routine mine operations, so that environmentally benign waste rock stacks can be constructed for permanent storage. Standard static characterisation techniques, such as acid neutralisation capacity (ANC), maximum potential acidity, and associated acid-base accounting, require laboratory tests that can be difficult to obtain rapidly at remote mine sites. We show that a combination of paste pH and a simple portable carbonate dissolution test, both techniques that can be done in the field in a 15 min time-frame, is useful for distinguishing rocks that are potentially acid-forming from those that are acid-neutralising. Use of these techniques could allow characterisation of mine wastes at the metre scale during mine excavation operations. Our application of these techniques to pyrite-bearing (total S = 1-4 wt%) but variably calcareous coal mine overburden shows that there is a strong correlation between the portable carbonate dissolution technique and laboratory-determined ANC measurements (range of 0-10 wt% calcite equivalent). Paste pH measurements on the same rocks are bimodal, with high-sulphur, low-calcite rocks yielding pH near 3 after 10 min, whereas high-ANC rocks yield paste pH of 7-8. In our coal mine example, the field tests were most effective when used in conjunction with stratigraphy. However, the same field tests have potential for routine use in any mine in which distinction of acid-generating rocks from acid-neutralising rocks is required. Calibration of field-based acid-base accounting characteristics of the rocks with laboratory-based static and/or kinetic tests is still necessary.

  15. Using synchrotron X-ray microtomography to characterize the pore network of reservoir rocks: A case study on carbonates

    NASA Astrophysics Data System (ADS)

    Arzilli, F.; Cilona, A.; Mancini, L.; Tondi, E.

    2016-09-01

    In this work we propose a new methodology to calculate pore connectivity in granular rocks. This method is useful to characterize the pore networks of natural and laboratory compaction bands (CBs), and compare them with the host rock pore network. Data were collected using the synchrotron X-ray microtomography technique and quantitative analyses were carried out using the Pore3D software library. The porosity was calculated from segmented tridimensional images of deformed and pristine rocks. A process of skeletonization of the pore space was used to obtain the number of connected pores within the rock volume. By analyzing the skeletons the differences between natural and laboratory CBs were highlighted. The natural CB has a lower porosity than to the laboratory one. In natural CBs, the grain contacts appear welded, whereas laboratory CBs show irregular pore shape. Moreover, we assessed for the first time how pore connectivity evolves as a function of deformation, documenting the mechanism responsible for pore connectivity drop within the CBs.

  16. Testing New Techniques for Mars Rover Rock-Drilling

    NASA Image and Video Library

    2017-10-23

    In the summer and fall of 2017, the team operating NASA's Curiosity Mars rover conducted tests in the "Mars Yard" at NASA's Jet Propulsion Laboratory, Pasadena, California, to develop techniques that Curiosity might be able to use to resume drilling into rocks on Mars. JPL robotics engineer Vladimir Arutyunov, in this June 29, 2017, photo, checks the test rover's drill bit at its contact point with a rock. Note that the stabilizer post visible to the right of the bit is not in contact with the rock, unlike the positioning used and photographed by Curiosity when drilling into rocks on Mars in 2013 to 2016. In late 2016, after Curiosity's drill had collected sample material from 15 Martian rocks, the drill's feed mechanism ceased working reliably. That motorized mechanism moved the bit forward or back with relation to the stabilizer posts on either side of the bit. In normal drilling by Curiosity, the stabilizers were positioned on the target rock first, and then the feed mechanism extended the rotation-percussion bit into the rock. In the alternative technique seen here, called "feed-extended drilling," the test rover's stabilizers are not used to touch the rock. The bit is advanced into the rock by motion of the robotic arm rather than the drill's feed mechanism. https://photojournal.jpl.nasa.gov/catalog/PIA22061

  17. Characterization of seismic properties across scales: from the laboratory- to the field scale

    NASA Astrophysics Data System (ADS)

    Grab, Melchior; Quintal, Beatriz; Caspari, Eva; Maurer, Hansruedi; Greenhalgh, Stewart

    2016-04-01

    When exploring geothermal systems, the main interest is on factors controlling the efficiency of the heat exchanger. This includes the energy state of the pore fluids and the presence of permeable structures building part of the fluid transport system. Seismic methods are amongst the most common exploration techniques to image the deep subsurface in order to evaluate such a geothermal heat exchanger. They make use of the fact that a seismic wave caries information on the properties of the rocks in the subsurface through which it passes. This enables the derivation of the stiffness and the density of the host rock from the seismic velocities. Moreover, it is well-known that the seismic waveforms are modulated while propagating trough the subsurface by visco-elastic effects due to wave induced fluid flow, hence, delivering information about the fluids in the rock's pore space. To constrain the interpretation of seismic data, that is, to link seismic properties with the fluid state and host rock permeability, it is common practice to measure the rock properties of small rock specimens in the laboratory under in-situ conditions. However, in magmatic geothermal systems or in systems situated in the crystalline basement, the host rock is often highly impermeable and fluid transport predominately takes place in fracture networks, consisting of fractures larger than the rock samples investigated in the laboratory. Therefore, laboratory experiments only provide the properties of relatively intact rock and an up-scaling procedure is required to characterize the seismic properties of large rock volumes containing fractures and fracture networks and to study the effects of fluids in such fractured rock. We present a technique to parameterize fractured rock volumes as typically encountered in Icelandic magmatic geothermal systems, by combining laboratory experiments with effective medium calculations. The resulting models can be used to calculate the frequency-dependent bulk

  18. Analysis of Fan Waves in a Laboratory Model Simulating the Propagation of Shear Ruptures in Rocks

    NASA Astrophysics Data System (ADS)

    Tarasov, B. G.; Sadovskii, V. M.; Sadovskaya, O. V.

    2017-12-01

    The fan-shaped mechanism of rotational motion transmission in a system of elastically bonded slabs on flat surface, simulating the propagation of shear ruptures in super brittle rocks, is analyzed. Such ruptures appear in the Earth's crust at seismogenic depths. They propagate due to the nucleation of oblique tensile microcracks, leading to the formation of a fan domino-structure in the rupture head. A laboratory physical model was created which demonstrates the process of fan-structure wave propagation. Equations of the dynamics of rotational motion of slabs as a mechanical system with a finite number of degrees of freedom are obtained. Based on the Merson method of solving the Cauchy problem for systems of ordinary differential equations, the computational algorithm taking into account contact interaction of slabs is developed. Within the framework of a simplified mathematical model of dynamic behavior of a fan-shaped system in the approximation of a continuous medium, the approximate estimates of the length of a fan depending on the velocity of its motion are obtained. It is shown that in the absence of friction a fan can move with any velocity that does not exceed the critical value, which depends on the size, the moment of inertia of slabs, the initial angle and the elasticity coefficient of bonds. In the presence of friction a fan stops. On the basis of discrete and continuous models, the main qualitative features of the behavior of a fan-structure moving under the action of applied tangential forces, whose values in a laboratory physical model are regulated by a change in the inclination angle of the rupture plane, are analyzed. Comparison of computations and laboratory measurements and observations shows good correspondence between the results.

  19. Cholinesterase (ChE) response and related mortality among birds fed ChE inhibitors

    USGS Publications Warehouse

    Ludke, J.L.; Hill, E.F.; Dieter, M.P.

    1975-01-01

    Patterns of mortality and inhibition of brain and plasma ChE in birds treated with ChE inhibitors were studied in an attempt to determine the validity of using ChE activity as a monitoring and diagnostic technique. Analysis of brain ChE activity proved to be reliable for diagnosing and monitoring effects of selected ChE inhibitors in birds. Brain ChE inhibition exceeding 20% indicated exposure, and inhibition greater than 50% was sufficient for diagnosing cause of death. Individuals that died from dietary exposure to parathion or carbofuran had brain ChE activities below 55% of normal; although individuals could survive with brain ChE activity lower than 50%. Problems associated with collection, storage, and analysis of tissues for ChE activity are discussed.

  20. Recent advances in analysis and prediction of Rock Falls, Rock Slides, and Rock Avalanches using 3D point clouds

    NASA Astrophysics Data System (ADS)

    Abellan, A.; Carrea, D.; Jaboyedoff, M.; Riquelme, A.; Tomas, R.; Royan, M. J.; Vilaplana, J. M.; Gauvin, N.

    2014-12-01

    The acquisition of dense terrain information using well-established 3D techniques (e.g. LiDAR, photogrammetry) and the use of new mobile platforms (e.g. Unmanned Aerial Vehicles) together with the increasingly efficient post-processing workflows for image treatment (e.g. Structure From Motion) are opening up new possibilities for analysing, modeling and predicting rock slope failures. Examples of applications at different scales ranging from the monitoring of small changes at unprecedented level of detail (e.g. sub millimeter-scale deformation under lab-scale conditions) to the detection of slope deformation at regional scale. In this communication we will show the main accomplishments of the Swiss National Foundation project "Characterizing and analysing 3D temporal slope evolution" carried out at Risk Analysis group (Univ. of Lausanne) in close collaboration with the RISKNAT and INTERES groups (Univ. of Barcelona and Univ. of Alicante, respectively). We have recently developed a series of innovative approaches for rock slope analysis using 3D point clouds, some examples include: the development of semi-automatic methodologies for the identification and extraction of rock-slope features such as discontinuities, type of material, rockfalls occurrence and deformation. Moreover, we have been improving our knowledge in progressive rupture characterization thanks to several algorithms, some examples include the computing of 3D deformation, the use of filtering techniques on permanently based TLS, the use of rock slope failure analogies at different scales (laboratory simulations, monitoring at glacier's front, etc.), the modelling of the influence of external forces such as precipitation on the acceleration of the deformation rate, etc. We have also been interested on the analysis of rock slope deformation prior to the occurrence of fragmental rockfalls and the interaction of this deformation with the spatial location of future events. In spite of these recent advances

  1. Restoration and PDS Archive of Apollo Lunar Rock Sample Data

    NASA Technical Reports Server (NTRS)

    Garcia, P. A.; Todd, N. S.; Lofgren, G. E.; Stefanov, W. L.; Runco, S. K.; LaBasse, D.; Gaddis, L. R.

    2011-01-01

    In 2008, scientists at the Johnson Space Center (JSC) Lunar Sample Laboratory and Image Science & Analysis Laboratory (under the auspices of the Astromaterials Research and Exploration Science Directorate or ARES) began work on a 4-year project to digitize the original film negatives of Apollo Lunar Rock Sample photographs. These rock samples together with lunar regolith and core samples were collected as part of the lander missions for Apollos 11, 12, 14, 15, 16 and 17. The original film negatives are stored at JSC under cryogenic conditions. This effort is data restoration in the truest sense. The images represent the only record available to scientists which allows them to view the rock samples when making a sample request. As the negatives are being scanned, they are also being formatted and documented for permanent archive in the NASA Planetary Data System (PDS) archive. The ARES group is working collaboratively with the Imaging Node of the PDS on the archiving.

  2. Proceedings of the scientific visit on crystalline rock repository development.

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mariner, Paul E.; Hardin, Ernest L.; Miksova, Jitka

    2013-02-01

    A scientific visit on Crystalline Rock Repository Development was held in the Czech Republic on September 24-27, 2012. The visit was hosted by the Czech Radioactive Waste Repository Authority (RAWRA), co-hosted by Sandia National Laboratories (SNL), and supported by the International Atomic Energy Agency (IAEA). The purpose of the visit was to promote technical information exchange between participants from countries engaged in the investigation and exploration of crystalline rock for the eventual construction of nuclear waste repositories. The visit was designed especially for participants of countries that have recently commenced (or recommenced) national repository programmes in crystalline host rock formations.more » Discussion topics included repository programme development, site screening and selection, site characterization, disposal concepts in crystalline host rock, regulatory frameworks, and safety assessment methodology. Interest was surveyed in establishing a %E2%80%9Cclub,%E2%80%9D the mission of which would be to identify and address the various technical challenges that confront the disposal of radioactive waste in crystalline rock environments. The idea of a second scientific visit to be held one year later in another host country received popular support. The visit concluded with a trip to the countryside south of Prague where participants were treated to a tour of the laboratory and underground facilities of the Josef Regional Underground Research Centre.« less

  3. Paleomagnetic and Rock Magnetic Study of Oligocene-Holocene Sedimentary Rocks from Northern Dominican Republic: Evidence of Vertical Axis Rotations

    NASA Astrophysics Data System (ADS)

    Anson Sanchez, M.; Kodama, K. P.; Pueyo, E. L.; Soto, R.; Garcia-Senz, J.; Escuder-Viruete, J.; Pastor-Galan, D.

    2017-12-01

    A paleomagnetic and rock magnetic study was conducted in the northern Dominican Republic to detect vertical axis rotations in an active left-lateral, strike slip fault zone. 191 samples from 21 sites were collected from a variety of lithologies including limestones, conglomerates, calcarenites and marls that ranged in age from the Oligocene to the Holocene. The rock magnetic portion of the study focused on the identification of magnetic minerals using coercivity, and Curie temperature (c vs temperature) measurement, modeling of IRM acquisition curves, and thermal demagnetization of IRMs (Lowrie, 19901). In the paleomagnetic portion of the study characteristic remanences (ChRMs) were isolated using thermal demagnetization (19 steps up to 680ºC) and alternating field (AF) demagnetization (17 steps up to 100 mT). In most cases the characteristic remanence is carried by magnetite, with peak unblocking temperatures of 575ºC. This interpretation was supported by c vs. T results that yielded Curie temperatures of 580˚C. In only a few cases (7 samples) higher unblocking temperatures suggested hematite as the magnetic carrier. The modeling of IRM acquisition curves, that shows two coercivity components, further supports the presence of magnetite. 75% of the IRM is carried by the low-coercivity component (100-300 mT, magnetite). 25% of the IRM is carried by the high-coercivity component (1.2-1.6T) characteristic of hematite. The IRM acquisition data was collected from 24 samples (3-4 from each of the lithologies sampled). IRMs were acquired in fields from 4mT to 1T in 23 steps. The paleomagnetic results show a grouping by tectonic blocks with one group having westerly ChRM declinations (268˚-295˚) and a second group having northerly ChRM declinations (357˚-035˚). In most cases, inclinations are intermediate ( 35˚), in agreement with the 24˚-31˚ expected inclinations for Dominican Republic in the period Oligocene to Holocene. The rotation of the tectonic blocks, as

  4. Dust Wind Tails Around Rocks

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This image was taken by the Sojourner rover's left front camera on Sol 32. The Pathfinder lander is at right and is about 9 meters away. Wind tails of dust are clearly seen extending from the left side of many of the small rocks in the foreground. The large rocks on the horizon at left center are the next goal of Sojourner as it continues our exploration of Mars.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and managed the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

  5. New superhindered polydentate polyphosphine ligands P(CH2CH2P(t)Bu2)3, PhP(CH2CH2P(t)Bu2)2, P(CH2CH2CH2P(t)Bu2)3, and their ruthenium(II) chloride complexes.

    PubMed

    Gilbert-Wilson, Ryan; Field, Leslie D; Bhadbhade, Mohan M

    2012-03-05

    The synthesis and characterization of the extremely hindered phosphine ligands, P(CH(2)CH(2)P(t)Bu(2))(3) (P(2)P(3)(tBu), 1), PhP(CH(2)CH(2)P(t)Bu(2))(2) (PhP(2)P(2)(tBu), 2), and P(CH(2)CH(2)CH(2)P(t)Bu(2))(3) (P(3)P(3)(tBu), 3) are reported, along with the synthesis and characterization of ruthenium chloro complexes RuCl(2)(P(2)P(3)(tBu)) (4), RuCl(2)(PhP(2)P(2)(tBu)) (5), and RuCl(2)(P(3)P(3)(tBu)) (6). The bulky P(2)P(3)(tBu) (1) and P(3)P(3)(tBu) (3) ligands are the most sterically encumbered PP(3)-type ligands so far synthesized, and in all cases, only three phosphorus donors are able to bind to the metal center. Complexes RuCl(2)(PhP(2)P(2)(tBu)) (5) and RuCl(2)(P(3)P(3)(tBu)) (6) were characterized by crystallography. Low temperature solution and solid state (31)P{(1)H} NMR were used to demonstrate that the structure of RuCl(2)(P(2)P(3)(tBu)) (4) is probably analogous to that of RuCl(2)(PhP(2)P(2)(tBu)) (5) which had been structurally characterized.

  6. Geological constraints for muon tomography: The world beyond standard rock

    NASA Astrophysics Data System (ADS)

    Lechmann, Alessandro; Mair, David; Ariga, Akitaka; Ariga, Tomoko; Ereditato, Antonio; Käser, Samuel; Nishiyama, Ryuichi; Scampoli, Paola; Vladymyrov, Mykhailo; Schlunegger, Fritz

    2017-04-01

    In present day muon tomography practice, one often encounters an experimental setup in which muons propagate several tens to a few hundreds of meters through a material to the detector. The goal of such an undertaking is usually centred on an attempt to make inferences from the measured muon flux to an anticipated subsurface structure. This can either be an underground interface geometry or a spatial material distribution. Inferences in this direction have until now mostly been done, thereby using the so called "standard rock" approximation. This includes a set of empirically determined parameters from several rocks found in the vicinity of physicist's laboratories. While this approach is reasonable to account for the effects of the tens of meters of soil/rock around a particle accelerator, we show, that for material thicknesses beyond that dimension, the elementary composition of the material (average atomic weight and atomic number) has a noticeable effect on the measured muon flux. Accordingly, the consecutive use of this approximation could potentially lead into a serious model bias, which in turn, might invalidate any tomographic inference, that base on this standard rock approximation. The parameters for standard rock are naturally close to a granitic (SiO2-rich) composition and thus can be safely used in such environments. As geophysical surveys are not restricted to any particular lithology, we investigated the effect of alternative rock compositions (carbonatic, basaltic and even ultramafic) and consequentially prefer to replace the standard rock approach with a dedicated geological investigation. Structural field data and laboratory measurements of density (He-Pycnometer) and composition (XRD) can be merged into an integrative geological model that can be used as an a priori constraint for the rock parameters of interest (density & composition) in the geophysical inversion. Modelling results show that when facing a non-granitic lithology the measured muon

  7. Quantifying the impact of lithology upon the mechanical properties of rock

    NASA Astrophysics Data System (ADS)

    Weatherley, Dion

    2013-04-01

    The physical characteristics of rock, its lithology, undoubtedly influences its deformation under natural or engineering loads. Mineral texture, micro-damage, joints, bedding planes, inclusions, unconformities and faults are all postulated to alter the mechanical response of rock on different scales and under different stressing conditions. Whilst laboratory studies have elucidated some aspects of the relationship between lithology and mechanical properties, these small-scale results are difficult to extrapolate to lithospheric scales. To augment laboratory-derived knowledge, physics-based numerical modelling is a promising avenue [3]. Bonded particle models implemented using the Discrete Element Method (DEM [1]) are a practical numerical laboratory to investigate the interplay between lithology and the mechanical response of rock specimens [4]. Numerical rock specimens are represented as an assembly of indivisible spherical particles connected to nearest neighbours via brittle-elastic beams which impart forces and moments upon one-another as particles move relative to each other. By applying boundary forces and solving Newton's Laws for each particle, elastic deformation and brittle failure may be simulated [2]. Each beam interaction is defined by four model parameters: Young's modulus, Poisson's ratio, cohesive strength and internal friction angle. Beam interactions in different subvolumes of the specimen are assigned different parameters to model different rock types or mineral assemblages. Micro-cracks, joints, unconformities and faults are geometrically incorporated by fitting particles to either side of triangulated surfaces [5]. The utility of this modelling approach is verified by reproducing analytical results from fracture mechanics (Griffith crack propagation and wing-crack formation) and results of controlled laboratory investigations. To quantify the impact of particular lithologic structures on mechanical response, a range of control experiments are

  8. Nitrogen release from rock and soil under simulated field conditions

    USGS Publications Warehouse

    Holloway, J.M.; Dahlgren, R.A.; Casey, W.H.

    2001-01-01

    A laboratory study was performed to simulate field weathering and nitrogen release from bedrock in a setting where geologic nitrogen has been suspected to be a large local source of nitrate. Two rock types containing nitrogen, slate (1370 mg N kg-1) and greenstone (480 mg N kg-1), were used along with saprolite and BC horizon sand from soils derived from these rock types. The fresh rock and weathered material were used in batch reactors that were leached every 30 days over 6 months to simulate a single wet season. Nitrogen was released from rock and soil materials at rates between 10-20 and 10-19 mo1 N cm-2 s-1. Results from the laboratory dissolution experiments were compared to in situ soil solutions and available mineral nitrogen pools from the BC horizon of both soils. Concentrations of mineral nitrogen (NO3- + NH4+) in soil solutions reached the highest levels at the beginning of the rainy season and progressively decreased with increased leaching. This seasonal pattern was repeated for the available mineral nitrogen pool that was extracted using a KCl solution. Estimates based on these laboratory release rates bracket stream water NO3-N fluxes and changes in the available mineral nitrogen pool over the active leaching period. These results confirm that geologic nitrogen, when present, may be a large and reactive pool that may contribute as a non-point source of nitrate contamination to surface and ground waters. ?? 2001 Elsevier Science B.V. All rights reserved.

  9. ChIA-PET2: a versatile and flexible pipeline for ChIA-PET data analysis

    PubMed Central

    Li, Guipeng; Chen, Yang; Snyder, Michael P.; Zhang, Michael Q.

    2017-01-01

    ChIA-PET2 is a versatile and flexible pipeline for analyzing different types of ChIA-PET data from raw sequencing reads to chromatin loops. ChIA-PET2 integrates all steps required for ChIA-PET data analysis, including linker trimming, read alignment, duplicate removal, peak calling and chromatin loop calling. It supports different kinds of ChIA-PET data generated from different ChIA-PET protocols and also provides quality controls for different steps of ChIA-PET analysis. In addition, ChIA-PET2 can use phased genotype data to call allele-specific chromatin interactions. We applied ChIA-PET2 to different ChIA-PET datasets, demonstrating its significantly improved performance as well as its ability to easily process ChIA-PET raw data. ChIA-PET2 is available at https://github.com/GuipengLi/ChIA-PET2. PMID:27625391

  10. Co-processing CH4 and oxygenates on Mo/H-ZSM-5: 2. CH4-CO2 and CH4-HCOOH mixtures.

    PubMed

    Bedard, Jeremy; Hong, Do-Young; Bhan, Aditya

    2013-08-07

    Co-processing of formic acid or carbon dioxide with CH4 (FA/CH4 = 0.01-0.03 and CO2/CH4 = 0.01-0.03) on Mo/H-ZSM-5 catalysts at 950 K with the prospect of kinetically coupling dehydrogenation and deoxygenation cycles results instead in a two-zone, staged bed reactor configuration consisting of upstream oxygenate/CH4 reforming and downstream CH4 dehydroaromatization. The addition of an oxygenate co-feed (oxygenate/CH4 = 0.01-0.03) causes oxidation of the active molybdenum carbide catalyst while producing CO and H2 until completely converted. Forward rates of C6H6 synthesis are unaffected by the introduction of an oxygenate co-feed after rigorously accounting for the thermodynamic reversibility caused by the H2 produced in oxygenate reforming reactions and the fraction of the active catalyst deemed unavailable for CH4 DHA. All effects of co-processing oxygenates with CH4 can be construed in terms of an approach to equilibrium.

  11. Infrared identification of the Criegee intermediates syn- and anti-CH3CHOO, and their distinct conformation-dependent reactivity

    PubMed Central

    Lin, Hui-Yu; Huang, Yu-Hsuan; Wang, Xiaohong; Bowman, Joel M.; Nishimura, Yoshifumi; Witek, Henryk A.; Lee, Yuan-Pern

    2015-01-01

    The Criegee intermediates are carbonyl oxides that play critical roles in ozonolysis of alkenes in the atmosphere. So far, the mid-infrared spectrum of only the simplest Criegee intermediate CH2OO has been reported. Methyl substitution of CH2OO produces two conformers of CH3CHOO and consequently complicates the infrared spectrum. Here we report the transient infrared spectrum of syn- and anti-CH3CHOO, produced from CH3CHI + O2 in a flow reactor, using a step-scan Fourier-transform spectrometer. Guided and supported by high-level full-dimensional quantum calculations, rotational contours of the four observed bands are simulated successfully and provide definitive identification of both conformers. Furthermore, anti-CH3CHOO shows a reactivity greater than syn-CH3CHOO towards NO/NO2; at the later period of reaction, the spectrum can be simulated with only syn-CH3CHOO. Without NO/NO2, anti-CH3CHOO also decays much faster than syn-CH3CHOO. The direct infrared detection of syn- and anti-CH3CHOO should prove useful for field measurements and laboratory investigations of the Criegee mechanism. PMID:25959902

  12. Yogi the rock

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Yogi, a rock taller than rover Sojourner, is the subject of this image, taken by the deployed Imager for Mars Pathfinder (IMP) on Sol 3. The soil in the foreground will be the location of multiple soil mechanics experiments performed by Sojourner's cleated wheels. Pathfinder scientists will be able to control the force inflicted on the soil beneath the rover's wheels, giving them insight into the soil's mechanical properties.

    The image was taken by the Imager for Mars Pathfinder (IMP) after its deployment on Sol 3. Mars Pathfinder was developed and managed by the Jet Propulsion Laboratory (JPL) for the National Aeronautics and Space Administration. JPL is an operating division of the California Institute of Technology (Caltech). The IMP was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

  13. Sorption and diffusion of selenium oxyanions in granitic rock

    NASA Astrophysics Data System (ADS)

    Ikonen, Jussi; Voutilainen, Mikko; Söderlund, Mervi; Jokelainen, Lalli; Siitari-Kauppi, Marja; Martin, Andrew

    2016-09-01

    The processes controlling diffusion and sorption of radionuclides have been studied extensively in the laboratory, whereas, only a few in-situ experiments have been carried out in order to study in-situ diffusion over the long-term (several years). This is largely due to the fact that in-situ experiments are typically time consuming and cost intensive, and it is commonly accepted that laboratory scale tests are well-established approaches to characterizing the properties of geological media. In order to assess the relevance of laboratory experiments, the Swiss National Cooperative for Disposal of Radioactive Waste (Nagra) have been conducting extensive experiments in the Underground Rock Laboratory (URL) at the Grimsel Test Site (GTS) in order to study radionuclide transport and retention in-situ. One of the elements used in these experiments is non-radioactive selenium, as an analog for the radiotoxic isotope Se-79, which is present in radioactive waste. In this work, two laboratory through-diffusion experiments using selenium as a tracer were carried out in block (decimeter) scale rock specimens to support one of the ongoing radionuclide transport and retention in-situ experiment at the GTS mentioned above. The though-diffusion tests of selenium were performed under atmospheric conditions in both Kuru grey granite (KGG) and Grimsel granodiorite (GG). The decrease of selenium concentration in an inlet hole drilled into each of the rock samples and the breakthrough of selenium into sampling holes drilled around the inlet were analyzed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The effective diffusion (De) and distribution coefficients (Kd) of selenium were then determined from the changes of selenium concentration in the inlet and sampling holes using a Time-Domain Diffusion (TDD) simulations. In addition, Kd of selenium was measured by batch sorption experiments as a function of pH and Se concentration in atmospheric conditions and nitrogen

  14. Rock melting technology and geothermal drilling

    NASA Technical Reports Server (NTRS)

    Rowley, J. C.

    1974-01-01

    National awareness of the potential future shortages in energy resources has heightened interest in exploration and utilization of a variety of geothermal energy (GTE) reservoirs. The status of conventional drilling of GTE wells is reviewed briefly and problem areas which lead to higher drilling costs are identified and R and D directions toward solution are suggested. In the immediate future, an expanded program of drilling in GTE formations can benefit from improvements in drilling equipment and technology normally associated with oil or gas wells. Over a longer time period, the new rock-melting drill bits being developed as a part of the Los Alamos Scientific Laboratory's Subterrene Program offer new solutions to a number of problems which frequently hamper GTE drilling, including the most basic problem - high temperature. Two of the most favorable characteristics of rock-melting penetrators are their ability to operate effectively in hot rock and produce glass linings around the hole as an integral part of the drilling process. The technical advantages to be gained by use of rock-melting penetrators are discussed in relation to the basic needs for GTE wells.

  15. Laboratory tools to quantify biogenic dissolution of rocks and minerals: a model rock biofilm growing in percolation columns

    NASA Astrophysics Data System (ADS)

    Seiffert, Franz; Bandow, Nicole; Kalbe, Ute; Milke, Ralf; Gorbushina, Anna

    2016-04-01

    Sub-aerial biofilms (SAB) are ubiquitous, self-sufficient microbial ecosystems found on mineral surfaces at all altitudes and latitudes. SABs, which are the principal causes of weathering on exposed terrestrial surfaces, are characterised by patchy growth dominated by associations of algae, cyanobacteria, fungi and heterotrophic bacteria. A recently developed in vitro system to study colonisation of rocks exposed to air included two key SAB participants - the rock-inhabiting ascomycete Knufia petricola (CBS 123872) and the phototrophic cyanobacterium Nostoc punctiforme ATCC29133. Both partners are genetically tractable and we used them here to study weathering of granite, K-feldspar and plagioclase. Small fragments of the various rocks or minerals (1 to 6 mm) were packed into flow-through columns and incubated with 0.1% glucose and 10 µM thiamine-hydrochloride (90 µL.min-1) to compare weathering with and without biofilms. Dissolution of the minerals was followed by: analysing (i) the degradation products in the effluent from the columns via Inductively Coupled Plasma Spectroscopy and (ii) by studying polished sections of the incubated mineral fragment/grains using scanning electron microscopy, transmission electron microscopy and energy dispersive X-ray analyses. K. petricola/N. punctiforme stimulated release of Ca, Na, Mg and Mn. Analyses of the polished sections confirmed depletion of Ca, Na and K near the surface of the fragments. The abrupt decrease in Ca concentration observed in peripheral areas of plagioclase fragments favoured a dissolution-reprecipitation mechanism. Percolation columns in combination with a model biofilm can thus be used to study weathering in closed systems. Columns can easily be filled with different minerals and biofilms, the effluent as well as grains can be collected after long-term exposure under axenic conditions and easily analysed.

  16. U–Pb, Rb–Sr, and U-series isotope geochemistry of rocks and fracture minerals from the Chalk River Laboratories site, Grenville Province, Ontario, Canada

    USGS Publications Warehouse

    Neymark, Leonid; Peterman, Zell E.; Moscati, Richard J.; Thivierge, R. H.

    2013-01-01

    As part of the Geologic Waste Management Facility feasibility study, Atomic Energy of Canada Ltd. (AECL) is evaluating the suitability of the Chalk River Laboratories (CRL) site in Ontario, situated in crystalline rock of the southwestern Grenville Province, for the possible development of an underground repository for low- and intermediate-level nuclear waste. This paper presents petrographic and trace element analyses, U–Pb zircon dating results, and Rb–Sr, U–Pb and U-series isotopic analyses of gneissic drill core samples from the deep CRG-series characterization boreholes at the CRL site. The main rock types intersected in the boreholes include hornblende–biotite (±pyroxene) gneisses of granitic to granodioritic composition, leucocratic granitic gneisses with sparse mafic minerals, and garnet-bearing gneisses with variable amounts of biotite and/or hornblende. The trace element data for whole-rock samples plot in the fields of within-plate, syn-collision, and volcanic arc-type granites in discrimination diagrams used for the tectonic interpretation of granitic rocks.Zircons separated from biotite gneiss and metagranite samples yielded SHRIMP-RG U–Pb ages of 1472 ± 14 (2σ) and 1045 ± 6 Ma, respectively, in very good agreement with widespread Early Mesoproterozoic plutonic ages and Ottawan orogeny ages in the Central Gneiss Belt. The Rb–Sr, U–Pb, and Pb–Pb whole-rock errorchron apparent ages of most of the CRL gneiss samples are consistent with zircon U–Pb age and do not indicate substantial large-scale preferential element mobility during superimposed metamorphic and water/rock interaction processes. This may confirm the integrity of the rock mass, which is a positive attribute for a potential nuclear waste repository. Most 234U/238U activity ratios (AR) in whole rock samples are within errors of the secular equilibrium value of one, indicating that the rocks have not experienced any appreciable U loss or gain within the past 1

  17. Knowledge representation of rock plastic deformation

    NASA Astrophysics Data System (ADS)

    Davarpanah, Armita; Babaie, Hassan

    2017-04-01

    The first iteration of the Rock Plastic Deformation (RPD) ontology models the semantics of the dynamic physical and chemical processes and mechanisms that occur during the deformation of the generally inhomogeneous polycrystalline rocks. The ontology represents the knowledge about the production, reconfiguration, displacement, and consumption of the structural components that participate in these processes. It also formalizes the properties that are known by the structural geology and metamorphic petrology communities to hold between the instances of the spatial components and the dynamic processes, the state and system variables, the empirical flow laws that relate the variables, and the laboratory testing conditions and procedures. The modeling of some of the complex physio-chemical, mathematical, and informational concepts and relations of the RPD ontology is based on the class and property structure of some well-established top-level ontologies. The flexible and extensible design of the initial version of the RPD ontology allows it to develop into a model that more fully represents the knowledge of plastic deformation of rocks under different spatial and temporal scales in the laboratory and in solid Earth. The ontology will be used to annotate the datasets related to the microstructures and physical-chemical processes that involve them. This will help the autonomous and globally distributed communities of experimental structural geologists and metamorphic petrologists to coherently and uniformly distribute, discover, access, share, and use their data through automated reasoning and enhanced data integration and software interoperability.

  18. Above- and belowground fluxes of CH4 from boreal shrubs and Scots pine

    NASA Astrophysics Data System (ADS)

    Halmeenmäki, Elisa; Heinonsalo, Jussi; Santalahti, Minna; Putkinen, Anuliina; Fritze, Hannu; Pihlatie, Mari

    2016-04-01

    Boreal upland forests are considered as an important sink for the greenhouse gas methane (CH4) due to CH4 oxidizing microbes in the soil. However, recent evidence suggests that vegetation can act as a significant source of CH4. Also, preliminary measurements indicate occasional emissions of CH4 above the tree canopies of a boreal forest. Nevertheless, the sources and the mechanisms of the observed CH4 emissions are still mostly unknown. Furthermore, the majority of CH4 flux studies have been conducted with the soil chamber method, thus not considering the role of the vegetation itself. We conducted a laboratory experiment to study separately the above- and belowground CH4 fluxes of bilberry (Vaccinium myrtillus), lingonberry (Vaccinium vitis-idaea), heather (Calluna vulgaris), and Scots pine (Pinus sylvestris), which were grown in microcosms. The above- and belowground fluxes of the plants were measured separately, and these fluxes were compared to fluxes of microcosms containing only humus soil. In addition to the flux measurements, we analysed the CH4 producing archaea (methanogens) and the CH4 consuming bacteria (methanotrophs) with the qPCR method to discover whether these microbes contribute to the CH4 exchange from the plant material and the soil. The results of the flux measurements indicate that the humus soil with roots of lingonberry, heather, and Scots pine consume CH4 compared to bare humus soil. Simultaneously, the shoots of heather and Scots pine emit small amounts of CH4. We did not find detectable amounts of methanogens from any of the samples, suggesting the produced CH4 could be of non-microbial origin, or produced by very small population of methanogens. Based on the first preliminary results, methanotrophs were present in all the studied plant species, and especially in high amounts in the rooted soils, thus implying that the methanotrophs could be responsible of the CH4 uptake in the root-soil systems.

  19. 3D Printing and Digital Rock Physics for Geomaterials

    NASA Astrophysics Data System (ADS)

    Martinez, M. J.; Yoon, H.; Dewers, T. A.

    2015-12-01

    Imaging techniques for the analysis of porous structures have revolutionized our ability to quantitatively characterize geomaterials. Digital representations of rock from CT images and physics modeling based on these pore structures provide the opportunity to further advance our quantitative understanding of fluid flow, geomechanics, and geochemistry, and the emergence of coupled behaviors. Additive manufacturing, commonly known as 3D printing, has revolutionized production of custom parts with complex internal geometries. For the geosciences, recent advances in 3D printing technology may be co-opted to print reproducible porous structures derived from CT-imaging of actual rocks for experimental testing. The use of 3D printed microstructure allows us to surmount typical problems associated with sample-to-sample heterogeneity that plague rock physics testing and to test material response independent from pore-structure variability. Together, imaging, digital rocks and 3D printing potentially enables a new workflow for understanding coupled geophysical processes in a real, but well-defined setting circumventing typical issues associated with reproducibility, enabling full characterization and thus connection of physical phenomena to structure. In this talk we will discuss the possibilities that these technologies can bring to geosciences and present early experiences with coupled multiscale experimental and numerical analysis using 3D printed fractured rock specimens. In particular, we discuss the processes of selection and printing of transparent fractured specimens based on 3D reconstruction of micro-fractured rock to study fluid flow characterization and manipulation. Micro-particle image velocimetry is used to directly visualize 3D single and multiphase flow velocity in 3D fracture networks. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U

  20. Photochemical Modeling of CH3 Abundances in the Outer Solar System

    NASA Technical Reports Server (NTRS)

    Lee, Anthony Y. T.; Yung, Yuk L.; Moses, Julianne

    2000-01-01

    Recent measurements of methyl radicals (CH3) in the upper atmospheres of Saturn and Neptune by the Infrared Space Observatory (ISO) provide new constraints to photochemical models of hydrocarbon chemistry in the outer solar system. The derived column abundances of CH3 on Saturn above 10 mbar and Neptune above the 0.2 mbar pressure level are (2.5 - 6.0) x 10(exp 13) / sq cm and (0.7 - 2.8) x 10(exp 13) / sq cm, respectively. We use the updated Caltech/Jet Propulsion Laboratory photochemical model, which incorporates hydrocarbon photochemistry, vertical molecular and bulk atmospheric eddy diffusion, and realistic radiative transfer modeling, to study the CH3 abundances in the upper atmosphere of the giant planets and Titan. We identify the key reactions that control the concentrations of CH3 in the model, such as the three-body recombination reaction, CH3 + CH3 + M yields C2H6 + M. We evaluate and extrapolate the three-body rate constant of this reaction to the low-temperature limit (1.8 x 10(exp -16) T(sup -3.75) e(sup -300/T), T < 300 K) and compare methyl radical abundances in five atmospheres: Jupiter, Saturn, Uranus, Neptune, and Titan. The sensitivity of our models to the rate coefficients for the reactions H + CH3 + M yields CH4 + M, H + C2H3 yields C2H2 + H2, (sup 1)CH2 + H2 yields CH3 + H, and H + C2H5 yields 2CH3, the branching ratios of CH4 photolysis, vertical mixing in the five atmospheres, and Lyman alpha photon enhancement at the orbit of Neptune have all been tested. The results of our model CH3 abundances for both Saturn (5.1 x 10(exp 13) / sq cm) and Neptune (2.2 x 10(exp 13) / sq cm) show good agreement with ISO Short Wavelength Spectrometer measurements. Using the same chemical reaction set, our calculations also successfully generate vertical profiles of stable hydrocarbons consistent with Voyager and ground-based measurements in these outer solar system atmospheres. Predictions of CH3 column concentrations (for p <= 0.2 mbar) in the atmospheres

  1. On the Application of Simple Experiments to the Teaching of ChE Thermodynamics

    ERIC Educational Resources Information Center

    McNeil, Kenneth M.

    1978-01-01

    This article describes the undergraduate ChE thermodynamics course at Drexel University and the reasons for incorporating a series of laboratory experiments into the course. Included is a list of lecture topics and a description of each of the experiments. (BB)

  2. ChIP-re-ChIP: Co-occupancy Analysis by Sequential Chromatin Immunoprecipitation.

    PubMed

    Beischlag, Timothy V; Prefontaine, Gratien G; Hankinson, Oliver

    2018-01-01

    Chromatin immunoprecipitation (ChIP) exploits the specific interactions between DNA and DNA-associated proteins. It can be used to examine a wide range of experimental parameters. A number of proteins bound at the same genomic location can identify a multi-protein chromatin complex where several proteins work together to regulate gene transcription or chromatin configuration. In many instances, this can be achieved using sequential ChIP; or simply, ChIP-re-ChIP. Whether it is for the examination of specific transcriptional or epigenetic regulators, or for the identification of cistromes, the ability to perform a sequential ChIP adds a higher level of power and definition to these analyses. In this chapter, we describe a simple and reliable method for the sequential ChIP assay.

  3. Lithologic mapping of silicate rocks using TIMS

    NASA Technical Reports Server (NTRS)

    Gillespie, A. R.

    1986-01-01

    Common rock-forming minerals have thermal infrared spectral features that are measured in the laboratory to infer composition. An airborne Daedalus scanner (TIMS) that collects six channels of thermal infrared radiance data (8 to 12 microns), may be used to measure these same features for rock identification. Previously, false-color composite pictures made from channels 1, 3, and 5 and emittance spectra for small areas on these images were used to make lithologic maps. Central wavelength, standard deviation, and amplitude of normal curves regressed on the emittance spectra are related to compositional information for crystalline igneous silicate rocks. As expected, the central wavelength varies systematically with silica content and with modal quartz content. Standard deviation is less sensitive to compositional changes, but large values may result from mixed admixture of vegetation. Compression of the six TIMS channels to three image channels made from the regressed parameters may be effective in improving geologic mapping from TIMS data, and these synthetic images may form a basis for the remote assessment of rock composition.

  4. Anharmonic Effect in CH3CH2C(=O)OCH2CH3 Decomposition

    NASA Astrophysics Data System (ADS)

    Ding, Yang; Song, Liguo; Yao, Li; Xia, Wenwen

    2017-12-01

    In this paper, using the B3LYP functional and CCSD(T) method with 6-311++G** basis set, the harmonic and anharmonic rate constants in the unimolecular dissociation of ethyl propanoate have been calculated using Rice-Ramsperger-Kassel-Marcus theory. The anharmonic rate constants of the title reaction have also been examined, the comparison shows that, the anharmonic effect especially in the case of high total energies and temperature for channels 3 to 6 is significant, so that the anharmonic effect cannot be neglected for unimolecular dissociation reaction of CH3CH2C(=O)OCH2CH3 both in microcanonical and canonical systems.

  5. C-H Hot Bands in the Near-IR Emission Spectra of Leonids

    NASA Technical Reports Server (NTRS)

    Freund, F. T.; Scoville, J.; Holm, R.; Seelemann, R.; Freund, M. M.

    2002-01-01

    The reported infrared (IR) emission spectra from 1999 Leonid fireballs show a 3.4 micron C-H emission band and unidentified bands at longer wavelengths. Upon atmospheric entry, the Leonid meteorites were flash-heated to temperatures around 2400K, which would destroy any organics on the surface of the meteorite grains. We propose that the nu(sub )CH emission band in the Leonid emission spectra arises from matrix-embedded C(sub n)-H-O entities that are protected from instant pyrolysis. Our model is based on IR absorption nu(sub )CH bands, which we observed in laboratory-grown MgO and natural olivine single crystals, where they arise from C(sub n)-H-O units imbedded in the mineral matrix, indicative of aliphatic -CH2- and -CH3 organics. Instead of being pyrolyzed, the C(sub n)-H-O entities in the Leonid trails become vibrationally excited to higher levels n = 1, 2, 3 etc. During de-excitation they emit at 3.4 microns, due to the (0 => 1) transition, and at longer wavelengths, due to hot bands. As a first step toward verifying this hypothesis we measured the C-H vibrational manifold of hexane (C6H14). The calculated positions of the (2 => l ) , (3 => 2), and possibly (4 => 3) hot bands agree with the Leonid emission bands at 3.5, 3.8 and 4.l microns.

  6. Test Image of Earth Rocks by Mars Camera Stereo

    NASA Image and Video Library

    2010-11-16

    This stereo view of terrestrial rocks combines two images taken by a testing twin of the Mars Hand Lens Imager MAHLI camera on NASA Mars Science Laboratory. 3D glasses are necessary to view this image.

  7. Accounting for GC-content bias reduces systematic errors and batch effects in ChIP-seq data.

    PubMed

    Teng, Mingxiang; Irizarry, Rafael A

    2017-11-01

    The main application of ChIP-seq technology is the detection of genomic regions that bind to a protein of interest. A large part of functional genomics' public catalogs is based on ChIP-seq data. These catalogs rely on peak calling algorithms that infer protein-binding sites by detecting genomic regions associated with more mapped reads (coverage) than expected by chance, as a result of the experimental protocol's lack of perfect specificity. We find that GC-content bias accounts for substantial variability in the observed coverage for ChIP-seq experiments and that this variability leads to false-positive peak calls. More concerning is that the GC effect varies across experiments, with the effect strong enough to result in a substantial number of peaks called differently when different laboratories perform experiments on the same cell line. However, accounting for GC content bias in ChIP-seq is challenging because the binding sites of interest tend to be more common in high GC-content regions, which confounds real biological signals with unwanted variability. To account for this challenge, we introduce a statistical approach that accounts for GC effects on both nonspecific noise and signal induced by the binding site. The method can be used to account for this bias in binding quantification as well to improve existing peak calling algorithms. We use this approach to show a reduction in false-positive peaks as well as improved consistency across laboratories. © 2017 Teng and Irizarry; Published by Cold Spring Harbor Laboratory Press.

  8. Anisotropy of electrical conductivity of the excavation damaged zone in the Mont Terri Underground Rock Laboratory

    NASA Astrophysics Data System (ADS)

    Nicollin, Florence; Gibert, Dominique; Lesparre, Nolwenn; Nussbaum, Christophe

    2010-04-01

    Electrical resistivity measurements were performed to characterize the anisotropy of electrical resistivity of the excavation damaged zone (EDZ) at the end-face of a gallery in the Opalinus clay of the Mont Terri Underground Rock Laboratory (URL). The data were acquired with a combination of square arrays in 18 zones on the gallery's face and in two series of four boreholes perpendicular to the face. Each data set is independently inverted using simulated annealing to recover the resistivity tensor. Both the stability and the non-uniqueness of the inverse problem are discussed with synthetic examples. The inversion of the data shows that the face is split in two domains separated by a tectonic fracture, with different resistivity values but with a common orientation. The direction of the maximum resistivity is found perpendicular to the bedding plane, and the direction of minimum resistivity is contained in the face's plane. These results show that the geo-electrical structure of the EDZ is controlled by a combination of effects due to tectonics, stratigraphy, and recent fracturing produced by the excavation of the gallery.

  9. Thermal effects of an ICL-based mid-infrared CH4 sensor within a wide atmospheric temperature range

    NASA Astrophysics Data System (ADS)

    Ye, Weilin; Zheng, Chuantao; Sanchez, Nancy P.; Girija, Aswathy V.; He, Qixin; Zheng, Huadan; Griffin, Robert J.; Tittel, Frank K.

    2018-03-01

    The thermal effects of an interband cascade laser (ICL) based mid-infrared methane (CH4) sensor that uses long-path absorption spectroscopy were studied. The sensor performance in the laboratory at a constant temperature of ∼25 °C was measured for 5 h and its Allan deviation was ∼2 ppbv with a 1 s averaging time. A LabVIEW-based simulation program was developed to study thermal effects on infrared absorption and a temperature compensation technique was developed to minimize these effects. An environmental test chamber was employed to investigate the thermal effects that occur in the sensor system with variation of the test chamber temperature between 10 and 30 °C. The thermal response of the sensor in a laboratory setting was observed using a 2.1 ppm CH4 standard gas sample. Indoor/outdoor CH4 measurements were conducted to evaluate the sensor performance within a wide atmospheric temperature range.

  10. Thermal effects of an ICL-based mid-infrared CH 4 sensor within a wide atmospheric temperature range

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ye, Weilin; Zheng, Chuantao; Sanchez, Nancy P.

    Here, thermal effects of an interband cascade laser (ICL) based mid-infrared methane (CH 4) sensor that uses long-path absorption spectroscopy were studied. The sensor performance in the laboratory at a constant temperature of ~ 25°C was measured for 5 hours and its Allan deviation was ~ 2 ppbv with a 1 s averaging time. A LabVIEW-based simulation program was developed to study thermal effects on infrared absorption and a temperature compensation technique was developed to control such effects. An environmental test chamber was employed to investigate thermal effects that occur in the sensor system with variation of the test chambermore » temperature between 10 and 30°C. The thermal response of the sensor in a laboratory setting was observed using a 2.1 ppm CH 4 standard gas sample. indoor/outdoor CH 4 measurements were conducted to evaluate the sensor performance within a wide atmospheric temperature range.« less

  11. Thermal effects of an ICL-based mid-infrared CH 4 sensor within a wide atmospheric temperature range

    DOE PAGES

    Ye, Weilin; Zheng, Chuantao; Sanchez, Nancy P.; ...

    2018-01-31

    Here, thermal effects of an interband cascade laser (ICL) based mid-infrared methane (CH 4) sensor that uses long-path absorption spectroscopy were studied. The sensor performance in the laboratory at a constant temperature of ~ 25°C was measured for 5 hours and its Allan deviation was ~ 2 ppbv with a 1 s averaging time. A LabVIEW-based simulation program was developed to study thermal effects on infrared absorption and a temperature compensation technique was developed to control such effects. An environmental test chamber was employed to investigate thermal effects that occur in the sensor system with variation of the test chambermore » temperature between 10 and 30°C. The thermal response of the sensor in a laboratory setting was observed using a 2.1 ppm CH 4 standard gas sample. indoor/outdoor CH 4 measurements were conducted to evaluate the sensor performance within a wide atmospheric temperature range.« less

  12. Planning and Analysis of Fractured Rock Injection Tests in the Cerro Brillador Underground Laboratory, Northern Chile

    NASA Astrophysics Data System (ADS)

    Fairley, J. P., Jr.; Oyarzún L, R.; Villegas, G.

    2015-12-01

    Early theories of fluid migration in unsaturated fractured rock hypothesized that matrix suction would dominate flow up to the point of matrix saturation. However, experiments in underground laboratories such as the ESF (Yucca Mountain, NV) have demonstrated that liquid water can migrate significant distances through fractures in an unsaturated porous medium, suggesting limited interaction between fractures and unsaturated matrix blocks and potentially rapid transmission of recharge to the sat- urated zone. Determining the conditions under which this rapid recharge may take place is an important factor in understanding deep percolation processes in arid areas with thick unsaturated zones. As part of an on-going, Fondecyt-funded project (award 11150587) to study mountain block hydrological processes in arid regions, we are plan- ning a series of in-situ fracture flow injection tests in the Cerro Brillador/Mina Escuela, an underground laboratory and teaching facility belonging to the Universidad la Serena, Chile. Planning for the tests is based on an analytical model and curve-matching method, originally developed to evaluate data from injection tests at Yucca Mountain (Fairley, J.P., 2010, WRR 46:W08542), that uses a known rate of liquid injection to a fracture (for example, from a packed-off section of borehole) and the observed rate of seepage discharging from the fracture to estimate effective fracture aperture, matrix sorptivity, fracture/matrix flow partitioning, and the wetted fracture/matrix interac- tion area between the injection and recovery points. We briefly review the analytical approach and its application to test planning and analysis, and describe the proposed tests and their goals.

  13. Data of rock analyses-VI. Bibliography and index of rock analyses in the periodical and serial literature of Scotland

    USGS Publications Warehouse

    Woodland, M.V.

    1959-01-01

    While Hutton fortified his convictions by constant appeals to the rocks themselves, his disciple Hall tested their truth in the laboratory. It is the boast of Scotland to have led the way in the application of chemical and physical experiment to the elucidation of geological history. Archibald Geikie, 1882. ?? 1959.

  14. Luminescent Copper(I) Halide Butterfly Dimers Coordinated to [Au(CH3imCH2py)2]BF4 and [Au(CH3imCH2quin)2]BF4

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Catalano, V.; Moore, A; Shearer, J

    2009-01-01

    The coordination chemistry of copper(I) halides to the homoleptic, N-heterocyclic carbene Au(I) complexes [Au(CH{sub 3}imCH{sub 2}quin){sub 2}]BF{sub 4} and [Au(CH{sub 3}imCH{sub 2}py){sub 2}]BF{sub 4} was explored. The reaction of CuX (X = Cl, Br, I) with either [Au(CH{sub 3}imCH{sub 2}quin){sub 2}]BF{sub 4} or [Au(CH{sub 3}imCH{sub 2}py){sub 2}]BF{sub 4} produces trimetallic complexes containing Cu{sub 2}X{sub 2}-butterfly copper clusters coordinated to the two imine moieties. The triangular arrangement of the metals places the gold(I) center in close proximity ({approx}2.5-2.6 {angstrom}) to the centroid of the Cu-Cu vector. The Cu-Cu separations vary as a function of bridging halide with the shortest Cu-Cu separationsmore » of {approx}2.5 {angstrom} found in the iodo-complexes and the longest separations of 2.9 {angstrom} found in the bridging chloride complexes. In all six complexes the Au-Cu separations range from {approx}2.8 to 3.0 {angstrom}. In the absence of halides, the dimetallic complex [AuCu(CH{sub 3}imCH{sub 2}py){sub 2}(NCCH{sub 3}){sub 2}](BF{sub 4}){sub 2}, containing a long Au-Cu distance of {approx}4.72 {angstrom} is formed. Additionally, as the byproduct of the reaction of CuBr with [Au(CH{sub 3}imCH{sub 2}quin){sub 2}]BF{sub 4} the deep-red, dimetallic compound, AuCuBr{sub 2}(CH{sub 3}imCH{sub 2}quin){sub 2}, was isolated in very low yield. All of these complexes were studied by NMR spectroscopy, mass spectrometry, and the copper containing species were additionally characterized by X-ray crystallography. In solution the copper centers dissociate from the gold complexes, but as shown by XANES and EXAFS spectroscopy, at low temperature the Cu-Cu linkage is broken, and the individual copper(I) halides reposition themselves to opposite sides of the gold complex while remaining coordinated to one imine moiety. In the solid state all of the complexes are photoluminescent, though the nature of the excited state was not determined.« less

  15. Methane and carbon at equilibrium in source rocks

    PubMed Central

    2013-01-01

    Methane in source rocks may not exist exclusively as free gas. It could exist in equilibrium with carbon and higher hydrocarbons: CH4 + C < = > Hydrocarbon. Three lines of evidence support this possibility. 1) Shales ingest gas in amounts and selectivities consistent with gas-carbon equilibrium. There is a 50% increase in solid hydrocarbon mass when Fayetteville Shale is exposed to methane (450 psi) under moderate conditions (100°C): Rock-Eval S2 (mg g-1) 8.5 = > 12.5. All light hydrocarbons are ingested, but with high selectivity, consistent with competitive addition to receptor sites in a growing polymer. Mowry Shale ingests butane vigorously from argon, for example, but not from methane under the same conditions. 2) Production data for a well producing from Fayetteville Shale declines along the theoretical curve for withdrawing gas from higher hydrocarbons in equilibrium with carbon. 3) A new general gas-solid equilibrium model accounts for natural gas at thermodynamic equilibrium, and C6-C7 hydrocarbons constrained to invariant compositions. The results make a strong case for methane in equilibrium with carbon and higher hydrocarbons. If correct, the higher hydrocarbons in source rocks are gas reservoirs, raising the possibility of substantially more gas in shales than analytically apparent, and far more gas in shale deposits than currently recognized. PMID:24330266

  16. Insight into subdecimeter fracturing processes during hydraulic fracture experiment in Äspö hard rock laboratory, Sweden

    NASA Astrophysics Data System (ADS)

    Kwiatek, Grzegorz; Martínez-Garzón, Patricia; Plenkers, Katrin; Leonhardt, Maria; Zang, Arno; Dresen, Georg; Bohnhoff, Marco

    2017-04-01

    We analyze the nano- and picoseismicity recorded during a hydraulic fracturing in-situ experiment performed in Äspö Hard Rock Laboratory, Sweden. The fracturing experiment included six fracture stages driven by three different water injection schemes (continuous, progressive and pulse pressurization) and was performed inside a 28 m long, horizontal borehole located at 410 m depth. The fracturing process was monitored with two different seismic networks covering a wide frequency band between 0.01 Hz and 100000 Hz and included broadband seismometers, geophones, high-frequency accelerometers and acoustic emission sensors. The combined seismic network allowed for detection and detailed analysis of seismicity with moment magnitudes MW<-4 (source sizes approx. on cm scale) that occurred solely during the hydraulic fracturing and refracturing stages. We relocated the seismicity catalog using the double-difference technique and calculated the source parameters (seismic moment, source size, stress drop, focal mechanism and seismic moment tensors). The physical characteristics of induced seismicity are compared to the stimulation parameters and to the formation parameters of the site. The seismic activity varies significantly depending on stimulation strategy with conventional, continuous stimulation being the most seismogenic. We find a systematic spatio-temporal migration of microseismic events (propagation away and towards wellbore injection interval) and temporal transitions in source mechanisms (opening - shearing - collapse) both being controlled by changes in fluid injection pressure. The derived focal mechanism parameters are in accordance with the local stress field orientation, and signify the reactivation of pre-existing rock flaws. The seismicity follows statistical and source scaling relations observed at different scales elsewhere, however, at an extremely low level of seismic efficiency.

  17. How Efficient is a Laboratory Burner in Heating Water?

    ERIC Educational Resources Information Center

    Jansen, Michael P.

    1997-01-01

    Describes an experiment in which chemistry students determine the efficiency of a laboratory burner used to heat water. The reaction is assumed to be the complete combustion of methane, CH4. The experiment is appropriate for secondary school chemistry students familiar with heats of reaction and simple calorimetry. Contains pre-laboratory and…

  18. Sedimentary Rocks and Methane - Southwest Arabia Terra

    NASA Technical Reports Server (NTRS)

    Allen, Carlton C.; Oehler, Dorothy Z.; Venechuk, Elizabeth M.

    2006-01-01

    We propose to land the Mars Science Laboratory in southwest Arabia Terra to study two key aspects of martian history the extensive record of sedimentary rocks and the continuing release of methane. The results of this exploration will directly address the MSL Scientific Objectives regarding biological potential, geology and geochemistry, and past habitability.

  19. Modeling Sr-90 Retardation by Fractured Rocks Based on the Results of In Situ and Laboratory Research

    NASA Astrophysics Data System (ADS)

    Samsanova, L.; Kotchergina, N. V.; Glinsky, M.; Zinin, A.; Ivanov, I.

    2001-12-01

    Industrial solutions from the surface storage of liquid radioactive wastes in Lake Karachay have been migrating in groundwaters for 50 years. Interaction of industrial solutions with fractured water-bearing rocks results in the formation of a plume body of contaminated rocks due to a partial retardation of the migrating radionuclides. In conducting research of the fractured rocks core samples from the wells located within the contaminated ground water plume, we have obtained empirical estimations of the retardation parameter (Sr-90 interphase distribution factor, Kd). To interpret the experimental data on Sr-90 Kd, a method of modeling of strontium-90 retardation by fractured rocks has been developed. The process of transient filtration for a flow fragment from Lake Karachay was reconstructed. Epignose modeling of the industrial solution's main flow migrating from Lake Karachay in south direction was performed. By solving the inverse tasks Kd of strontium-90 was estimated for the fractured rocks.

  20. Laboratory Rotational Spectroscopy of Astrophysical Interesting Diatomic Hydrides

    NASA Astrophysics Data System (ADS)

    Halfen, DeWayne; Ziurys, L.

    2008-05-01

    Diatomic hydride are among the most common molecular species in the interstellar medium (ISM). The low molecular mass and thus moments of inertia cause their rotational spectra to lie entirely in the submillimeter and far-infrared regions. Hence, the future airborne and space-borne platforms, such as SOFIA and Herschel, are primed to explore these prevalent molecules. However, in order to detect these species in the ISM, their rotational spectra must first be measured in the laboratory. Using submillimeter direct absorption methods in the Ziurys laboratory, we have recorded the spectra of several diatomic hydrides of astrophysical interest. We have measured the pure rotational spectrum of MnH (X7Σ+: N = 0 - 1) and MnD (N = 2 - 3), as well as the deuterium and carbon-13 isotopologues of CH, CD (X2Πr: N = 1 - 1 and 1 - 2) and 13CH (N = 1 - 1). Manganese hydride and deuteride were created in a DC discharge of H2 or D2 and manganese vapor, generated in a Broida-type oven. CD and 13CH were produced in an AC discharge of argon and CD4 or 13CH4. For MnH, the five strongest manganese hyperfine transitions were recorded in its N = 0 - 1 transition, each of which are additionally split by hydrogen hyperfine interactions. CD and 13CH also have multiple hyperfine components due to the D, 13C, and/or H atoms. The direct measurement of these fundamental transitions will allow for unambiguous astronomical detections. The results of these studies will be presented.

  1. CH-53K Heavy Lift Replacement Helicopter (CH-53K)

    DTIC Science & Technology

    2015-12-01

    Selected Acquisition Report (SAR) RCS: DD-A&T(Q&A)823-390 CH-53K Heavy Lift Replacement Helicopter (CH-53K) As of FY 2017 President’s Budget...December 2015 SAR March 4, 2016 10:04:18 UNCLASSIFIED 4 Col Henry Vanderborght PMA-261 Heavy Lift Helicopters Program Executive Office - Air, Anti...Replacement Helicopter (CH-53K) DoD Component Navy Responsible Office References SAR Baseline (Development Estimate) Defense Acquisition Executive (DAE

  2. Dual stable isotopes of CH 4 from Yellowstone hot-springs suggest hydrothermal processes involving magmatic CO 2

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Moran, James J.; Whitmore, Laura M.; Jay, Zackary J.

    Volcanism and post-magmatism contribute significant annual methane (CH 4) fluxes to the atmosphere (on par with other natural sources such as forest fire and wild animal emissions) and have been implicated in past climate-change events. The Yellowstone hot spot is one of the largest volcanic systems on Earth and is known to emit CH 4 (as well as carbon dioxide (CO 2) and other gases), but the ultimate sources of this CH 4 flux have not been elucidated. In this paper, we use dual stable isotope analysis (δ 2H and δ 13C) of CH 4 sampled from ten high-temperature geothermalmore » pools in Yellowstone National Park along with other isotopic and gas analyses to evaluate potential sources of methane. The average δ 13C and δ 2H values of CH 4 emitted from hot springs ( 26.7 (± 2.4) and - 236.9 (± 12.0) ‰, respectively) are inconsistent with microbial methanogenesis but do not allow distinction between thermogenic and abiotic sources. Correlation between δ 13C CH4 and δ 13C of dissolved inorganic C (DIC) is consistent with DIC as the parent C source for the observed CH 4, or with equilibration of CH 4 and DIC. Methane formation temperatures estimated by isotopic geothermometry based on δ 13C CH4 and δ 13C CO2 ranged from ~ 250–350 °C, which is just below previous temperature estimates for the hydrothermal reservoir. Further, the δ 2H H2O of the thermal springs and the measured δ 2H CH4 values are consistent with equilibration between the source water and the CH 4 at the formation temperatures. Though the ultimate origin of the CH 4 could be attributed to either abiotic of themorgenic processes with subsequent isotopic equilibration, the C 1/C 2+ composition of the gases is more consistent with abiotic origins for most of the samples. Finally, our data support the hypothesis that subsurface rock-water interactions are responsible for at least a significant fraction of the CH 4 flux from the Yellowstone National Park volcanic system.« less

  3. Dual stable isotopes of CH 4 from Yellowstone hot-springs suggest hydrothermal processes involving magmatic CO 2

    DOE PAGES

    Moran, James J.; Whitmore, Laura M.; Jay, Zackary J.; ...

    2017-05-16

    Volcanism and post-magmatism contribute significant annual methane (CH 4) fluxes to the atmosphere (on par with other natural sources such as forest fire and wild animal emissions) and have been implicated in past climate-change events. The Yellowstone hot spot is one of the largest volcanic systems on Earth and is known to emit CH 4 (as well as carbon dioxide (CO 2) and other gases), but the ultimate sources of this CH 4 flux have not been elucidated. In this paper, we use dual stable isotope analysis (δ 2H and δ 13C) of CH 4 sampled from ten high-temperature geothermalmore » pools in Yellowstone National Park along with other isotopic and gas analyses to evaluate potential sources of methane. The average δ 13C and δ 2H values of CH 4 emitted from hot springs ( 26.7 (± 2.4) and - 236.9 (± 12.0) ‰, respectively) are inconsistent with microbial methanogenesis but do not allow distinction between thermogenic and abiotic sources. Correlation between δ 13C CH4 and δ 13C of dissolved inorganic C (DIC) is consistent with DIC as the parent C source for the observed CH 4, or with equilibration of CH 4 and DIC. Methane formation temperatures estimated by isotopic geothermometry based on δ 13C CH4 and δ 13C CO2 ranged from ~ 250–350 °C, which is just below previous temperature estimates for the hydrothermal reservoir. Further, the δ 2H H2O of the thermal springs and the measured δ 2H CH4 values are consistent with equilibration between the source water and the CH 4 at the formation temperatures. Though the ultimate origin of the CH 4 could be attributed to either abiotic of themorgenic processes with subsequent isotopic equilibration, the C 1/C 2+ composition of the gases is more consistent with abiotic origins for most of the samples. Finally, our data support the hypothesis that subsurface rock-water interactions are responsible for at least a significant fraction of the CH 4 flux from the Yellowstone National Park volcanic system.« less

  4. The bowing potential of granitic rocks: rock fabrics, thermal properties and residual strain

    NASA Astrophysics Data System (ADS)

    Siegesmund, S.; Mosch, S.; Scheffzük, Ch.; Nikolayev, D. I.

    2008-10-01

    The bowing of natural stone panels is especially known for marble slabs. The bowing of granite is mainly known from tombstones in subtropical humid climate. Field inspections in combination with laboratory investigations with respect to the thermal expansion and the bowing potential was performed on two different granitoids (Cezlak granodiorite and Flossenbürg granite) which differ in the composition and rock fabrics. In addition, to describe and explain the effect of bowing of granitoid facade panels, neutron time-of-flight diffraction was applied to determine residual macro- and microstrain. The measurements were combined with investigations of the crystallographic preferred orientation of quartz and biotite. Both samples show a significant bowing as a function of panel thickness and destination temperature. In comparison to marbles the effect of bowing is more pronounced in granitoids at temperatures of 120°C. The bowing as well as the thermal expansion of the Cezlak sample is also anisotropic with respect to the rock fabrics. A quantitative estimate was performed based on the observed textures. The effect of the locked-in stresses may also have a control on the bowing together with the thermal stresses related to the different volume expansion of the rock-forming minerals.

  5. Dynamics of the F(-) + CH3I → HF + CH2I(-) Proton Transfer Reaction.

    PubMed

    Zhang, Jiaxu; Xie, Jing; Hase, William L

    2015-12-17

    Direct chemical dynamics simulations, at collision energies Erel of 0.32 and 1.53 eV, were performed to obtain an atomistic understanding of the F(-) + CH3I reaction dynamics. There is only the F(-) + CH3I → CH3F + I(-) bimolecular nucleophilic substitution SN2 product channel at 0.32 eV. Increasing Erel to 1.53 eV opens the endothermic F(-) + CH3I → HF + CH2I(-) proton transfer reaction, which is less competitive than the SN2 reaction. The simulations reveal proton transfer occurs by two direct atomic-level mechanisms, rebound and stripping, and indirect mechanisms, involving formation of the F(-)···HCH2I complex and the roundabout. For the indirect trajectories all of the CH2I(-) is formed with zero-point energy (ZPE), while for the direct trajectories 50% form CH2I(-) without ZPE. Without a ZPE constraint for CH2I(-), the reaction cross sections for the rebound, stripping, and indirect mechanisms are 0.2 ± 0.1, 1.2 ± 0.4, and 0.7 ± 0.2 Å(2), respectively. Discarding trajectories that do not form CH2I(-) with ZPE reduces the rebound and stripping cross sections to 0.1 ± 0.1 and 0.7 ± 0.5 Å(2). The HF product is formed rotationally and vibrationally unexcited. The average value of J is 2.6 and with histogram binning n = 0. CH2I(-) is formed rotationally excited. The partitioning between CH2I(-) vibration and HF + CH2I(-) relative translation energy depends on the treatment of CH2I(-) ZPE. Without a CH2I(-) ZPE constraint the energy partitioning is primarily to relative translation with little CH2I(-) vibration. With a ZPE constraint, energy partitioning to CH2I(-) rotation, CH2I(-) vibration, and relative translation are statistically the same. The overall F(-) + CH3I rate constant at Erel of both 0.32 and 1.53 eV is in good agreement with experiment and negligibly affected by the treatment of CH2I(-) ZPE, since the SN2 reaction is the major contributor to the total reaction rate constant. The potential energy surface and reaction dynamics for F

  6. Odyssey/White Rock

    NASA Technical Reports Server (NTRS)

    2002-01-01

    These Mars Odyssey images show the 'White Rock' feature on Mars in both infrared (left) and visible (right) wavelengths. The images were acquired simultaneously on March 11, 2002. The box shows where the visible image is located in the infrared image. 'White Rock' is the unofficial name for this unusual landform that was first observed during the Mariner 9 mission in the early 1970's. The variations in brightness in the infrared image are due to differences in surface temperature, where dark is cool and bright is warm. The dramatic differences between the infrared and visible views of White Rock are the result of solar heating. The relatively bright surfaces observed at visible wavelengths reflect more solar energy than the darker surfaces, allowing them to stay cooler and thus they appear dark in the infrared image. The new thermal emission imaging system data will help to address the long standing question of whether the White Rock deposit was produced in an ancient crater lake or by dry processes of volcanic or wind deposition. The infrared image has a resolution of 100 meters (328 feet) per pixel and is 32 kilometers (20 miles) wide. The visible image has a resolution of 18 meters per pixel and is approximately 18 kilometers (11 miles) wide. The images are centered at 8.2 degrees south latitude and 24.9 degrees east longitude.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  7. Understanding the signature of rock coatings in laser-induced breakdown spectroscopy data

    USGS Publications Warehouse

    Lanza, Nina L.; Ollila, Ann M.; Cousin, Agnes; Wiens, Roger C.; Clegg, Samuel M.; Mangold, Nicolas; Bridges, Nathan; Cooper, Daniel; Schmidt, Mariek E.; Berger, Jeffrey; Arvidson, Raymond E.; Melikechi, Noureddine; Newsom, Horton E.; Tokar, Robert; Hardgrove, Craig; Mezzacappa, Alissa; Jackson, Ryan S.; Clark, Benton C.; Forni, Olivier; Maurice, Sylvestre; Nachon, Marion; Anderson, Ryan B.; Blank, Jennifer; Deans, Matthew; Delapp, Dorothea; Léveillé, Richard; McInroy, Rhonda; Martinez, Ronald; Meslin, Pierre-Yves; Pinet, Patrick

    2015-01-01

    Surface compositional features on rocks such as coatings and weathering rinds provide important information about past aqueous environments and water–rock interactions. The search for these features represents an important aspect of the Curiosity rover mission. With its unique ability to do fine-scale chemical depth profiling, the ChemCam laser-induced breakdown spectroscopy instrument (LIBS) onboard Curiosity can be used to both identify and analyze rock surface alteration features. In this study we analyze a terrestrial manganese-rich rock varnish coating on a basalt rock in the laboratory with the ChemCam engineering model to determine the LIBS signature of a natural rock coating. Results show that there is a systematic decrease in peak heights for elements such as Mn that are abundant in the coating but not the rock. There is significant spatial variation in the relative abundance of coating elements detected by LIBS depending on where on the rock surface sampled; this is due to the variability in thickness and spatial discontinuities in the coating. Similar trends have been identified in some martian rock targets in ChemCam data, suggesting that these rocks may have coatings or weathering rinds on their surfaces.

  8. Dual stable isotopes of CH 4 from Yellowstone hot-springs suggest hydrothermal processes involving magmatic CO 2

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Moran, James J.; Whitmore, Laura M.; Jay, Zackary J.

    Volcanism and post-magmatism contribute both significant annual CH 4 fluxes to the atmosphere (on par with other natural sources such as forest fire and wild animal emissions) and have been implicated in past climate-change events. The Yellowstone hot spot is one of the largest volcanic systems on Earth and is known to emit methane in addition to other greenhouse gases (e.g. carbon dioxide) but the ultimate source of this methane flux has not been elucidated. Here we use dual stable isotope analysis (δ 2H and δ 13C) of CH 4(g) sampled from ten high-temperature geothermal pools in Yellowstone National Parkmore » to show that the predominant flux of CH4(g) is abiotic. The average δ 13C and δ 2H values of CH 4(g) emitted from hot springs (-26.7 (±2.4) and -236.9 (±12.0) ‰, respectively) are not consistent with biotic (microbial or thermogenic) methane sources, but are within previously reported ranges for abiotic methane production. Correlation between δ 13C CH4 and δ 13C-dissolved inorganic C (DIC) also suggests that CO 2 is a parent C source for the observed CH 4(g). Moreover, CH 4-CO 2 isotopic geothermometry was used to estimate CH 4(g) formation temperatures ranging from ~ 250 - 350°C, which is just below the temperature estimated for the hydrothermal reservoir and consistent with the hypothesis that subsurface, rock-water interactions are responsible for large methane fluxes from this volcanic system. An understanding of conditions leading to the abiotic production of methane and associated isotopic signatures are central to understanding the evolutionary history of deep carbon sources on Earth.« less

  9. Sorption and diffusion of selenium oxyanions in granitic rock.

    PubMed

    Ikonen, Jussi; Voutilainen, Mikko; Söderlund, Mervi; Jokelainen, Lalli; Siitari-Kauppi, Marja; Martin, Andrew

    2016-09-01

    The processes controlling diffusion and sorption of radionuclides have been studied extensively in the laboratory, whereas, only a few in-situ experiments have been carried out in order to study in-situ diffusion over the long-term (several years). This is largely due to the fact that in-situ experiments are typically time consuming and cost intensive, and it is commonly accepted that laboratory scale tests are well-established approaches to characterizing the properties of geological media. In order to assess the relevance of laboratory experiments, the Swiss National Cooperative for Disposal of Radioactive Waste (Nagra) have been conducting extensive experiments in the Underground Rock Laboratory (URL) at the Grimsel Test Site (GTS) in order to study radionuclide transport and retention in-situ. One of the elements used in these experiments is non-radioactive selenium, as an analog for the radiotoxic isotope Se-79, which is present in radioactive waste. In this work, two laboratory through-diffusion experiments using selenium as a tracer were carried out in block (decimeter) scale rock specimens to support one of the ongoing radionuclide transport and retention in-situ experiment at the GTS mentioned above. The though-diffusion tests of selenium were performed under atmospheric conditions in both Kuru grey granite (KGG) and Grimsel granodiorite (GG). The decrease of selenium concentration in an inlet hole drilled into each of the rock samples and the breakthrough of selenium into sampling holes drilled around the inlet were analyzed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The effective diffusion (De) and distribution coefficients (Kd) of selenium were then determined from the changes of selenium concentration in the inlet and sampling holes using a Time-Domain Diffusion (TDD) simulations. In addition, Kd of selenium was measured by batch sorption experiments as a function of pH and Se concentration in atmospheric conditions and nitrogen

  10. Capture and dissociation in the complex-forming CH + H2 → CH2 + H, CH + H2 reactions.

    PubMed

    González, Miguel; Saracibar, Amaia; Garcia, Ernesto

    2011-02-28

    The rate coefficients for the capture process CH + H(2)→ CH(3) and the reactions CH + H(2)→ CH(2) + H (abstraction), CH + H(2) (exchange) have been calculated in the 200-800 K temperature range, using the quasiclassical trajectory (QCT) method and the most recent global potential energy surface. The reactions, which are of interest in combustion and in astrochemistry, proceed via the formation of long-lived CH(3) collision complexes, and the three H atoms become equivalent. QCT rate coefficients for capture are in quite good agreement with experiments. However, an important zero point energy (ZPE) leakage problem occurs in the QCT calculations for the abstraction, exchange and inelastic exit channels. To account for this issue, a pragmatic but accurate approach has been applied, leading to a good agreement with experimental abstraction rate coefficients. Exchange rate coefficients have also been calculated using this approach. Finally, calculations employing QCT capture/phase space theory (PST) models have been carried out, leading to similar values for the abstraction rate coefficients as the QCT and previous quantum mechanical capture/PST methods. This suggests that QCT capture/PST models are a good alternative to the QCT method for this and similar systems.

  11. The permeability of fractured rocks in pressurised volcanic and geothermal systems.

    PubMed

    Lamur, A; Kendrick, J E; Eggertsson, G H; Wall, R J; Ashworth, J D; Lavallée, Y

    2017-07-21

    The connectivity of rocks' porous structure and the presence of fractures influence the transfer of fluids in the Earth's crust. Here, we employed laboratory experiments to measure the influence of macro-fractures and effective pressure on the permeability of volcanic rocks with a wide range of initial porosities (1-41 vol. %) comprised of both vesicles and micro-cracks. We used a hand-held permeameter and hydrostatic cell to measure the permeability of intact rock cores at effective pressures up to 30 MPa; we then induced a macro-fracture to each sample using Brazilian tensile tests and measured the permeability of these macro-fractured rocks again. We show that intact rock permeability increases non-linearly with increasing porosity and decreases with increasing effective pressure due to compactional closure of micro-fractures. Imparting a macro-fracture both increases the permeability of rocks and their sensitivity to effective pressure. The magnitude of permeability increase induced by the macro-fracture is more significant for dense rocks. We finally provide a general equation to estimate the permeability of intact and fractured rocks, forming a basis to constrain fluid flow in volcanic and geothermal systems.

  12. Rippability Assessment of Weathered Sedimentary Rock Mass using Seismic Refraction Methods

    NASA Astrophysics Data System (ADS)

    Ismail, M. A. M.; Kumar, N. S.; Abidin, M. H. Z.; Madun, A.

    2018-04-01

    Rippability or ease of excavation in sedimentary rocks is a significant aspect of the preliminary work of any civil engineering project. Rippability assessment was performed in this study to select an available ripping machine to rip off earth materials using the seismic velocity chart provided by Caterpillar. The research area is located at the proposed construction site for the development of a water reservoir and related infrastructure in Kampus Pauh Putra, Universiti Malaysia Perlis. The research was aimed at obtaining seismic velocity, P-wave (Vp) using a seismic refraction method to produce a 2D tomography model. A 2D seismic model was used to delineate the layers into the velocity profile. The conventional geotechnical method of using a borehole was integrated with the seismic velocity method to provide appropriate correlation. The correlated data can be used to categorize machineries for excavation activities based on the available systematic analysis procedure to predict rock rippability. The seismic velocity profile obtained was used to interpret rock layers within the ranges labelled as rippable, marginal, and non-rippable. Based on the seismic velocity method the site can be classified into loose sand stone to moderately weathered rock. Laboratory test results shows that the site’s rock material falls between low strength and high strength. Results suggest that Caterpillar’s smallest ripper, namely, D8R, can successfully excavate materials based on the test results integration from seismic velocity method and laboratory test.

  13. Numerical Simulation of Electrical Properties of Carbonate Reservoir Rocks Using µCT Images

    NASA Astrophysics Data System (ADS)

    Colgin, J.; Niu, Q.; Zhang, C.; Zhang, F.

    2017-12-01

    Digital rock physics involves the modern microscopic imaging of geomaterials, digitalization of the microstructure, and numerical simulation of physical properties of rocks. This physics-based approach can give important insight into understanding properties of reservoir rocks, and help reveal the link between intrinsic rock properties and macroscopic geophysical responses. The focus of this study is the simulation of the complex conductivity of carbonate reservoir rocks using reconstructed 3D rock structures from high-resolution X-ray micro computed tomography (µCT). Carbonate core samples with varying lithofacies and pore structures from the Cambro-Ordovician Arbuckle Group and the Upper Pennsylvanian Lansing-Kansas City Group in Kansas are used in this study. The wide variations in pore geometry and connectivity of these samples were imaged using µCT. A two-phase segmentation method was used to reconstruct a digital rock of solid particles and pores. We then calculate the effective electrical conductivity of the digital rock volume using a pore-scale numerical approach. The complex conductivity of geomaterials is influenced by the electrical properties and geometry of each phase, i.e., the solid and fluid phases. In addition, the electrical double layer that forms between the solid and fluid phases can also affect the effective conductivity of the material. In the numerical modeling, the influence of the electrical double layer is quantified by a complex surface conductance and converted to an apparent volumetric complex conductivity of either solid particles or pore fluid. The effective complex conductivity resulting from numerical simulations based on µCT images will be compared to results from laboratory experiments on equivalent rock samples. The imaging and digital segmentation method, assumptions in the numerical simulation, and trends as compared to laboratory results will be discussed. This study will help us understand how microscale physics affects

  14. Rock sample brought to earth from the Apollo 12 lunar landing mission

    NASA Technical Reports Server (NTRS)

    1969-01-01

    Close-up view of Apollo 12 sample 12,052 under observation in the Manned Spacecraft Center's Lunar Receiving Laboratory. This sample, collected during the second Apollo 12 extravehicular activity (EVA-2) of Astronauts Charles Conrad Jr., and Alan L. Bean, is a typical fine-grained crystalline rock with a concentration of holes on the left part of the exposed side. These holes are called vesicles and have been labeled as gas bubbles formed during the crystallization of the rock. Several glass-lined pits can be seen on the surface of the rock. An idea of the size of the rock can be gained by reference to the gauge on the bottom portion of the number meter.

  15. PDS Archive Release of Apollo 11, Apollo 12, and Apollo 17 Lunar Rock Sample Images

    NASA Technical Reports Server (NTRS)

    Garcia, P. A.; Stefanov, W. L.; Lofgren, G. E.; Todd, N. S.; Gaddis, L. R.

    2013-01-01

    Scientists at the Johnson Space Center (JSC) Lunar Sample Laboratory, Information Resources Directorate, and Image Science & Analysis Laboratory have been working to digitize (scan) the original film negatives of Apollo Lunar Rock Sample photographs [1, 2]. The rock samples, and associated regolith and lunar core samples, were obtained during the Apollo 11, 12, 14, 15, 16 and 17 missions. The images allow scientists to view the individual rock samples in their original or subdivided state prior to requesting physical samples for their research. In cases where access to the actual physical samples is not practical, the images provide an alternate mechanism for study of the subject samples. As the negatives are being scanned, they have been formatted and documented for permanent archive in the NASA Planetary Data System (PDS). The Astromaterials Research and Exploration Science Directorate (which includes the Lunar Sample Laboratory and Image Science & Analysis Laboratory) at JSC is working collaboratively with the Imaging Node of the PDS on the archiving of these valuable data. The PDS Imaging Node is now pleased to announce the release of the image archives for Apollo missions 11, 12, and 17.

  16. Thermal Inertia of Rocks and Rock Populations

    NASA Technical Reports Server (NTRS)

    Golombek, M. P.; Jakosky, B. M.; Mellon, M. T.

    2001-01-01

    The effective thermal inertia of rock populations on Mars and Earth is derived from a model of effective inertia versus rock diameter. Results allow a parameterization of the effective rock inertia versus rock abundance and bulk and fine component inertia. Additional information is contained in the original extended abstract.

  17. Characterization of rock thermal conductivity by high-resolution optical scanning

    USGS Publications Warehouse

    Popov, Y.A.; Pribnow, D.F.C.; Sass, J.H.; Williams, C.F.; Burkhardt, H.

    1999-01-01

    We compared thress laboratory methods for thermal conductivity measurements: divided-bar, line-source and optical scanning. These methods are widely used in geothermal and petrophysical studies, particularly as applied to research on cores from deep scientific boreholes. The relatively new optical scanning method has recently been perfected and applied to geophysical problems. A comparison among these methods for determining the thermal conductivity tensor for anisotropic rocks is based on a representative collection of 80 crystalline rock samples from the KTB continental deep borehole (Germany). Despite substantial thermal inhomogeneity of rock thermal conductivity (up to 40-50% variation) and high anisotropy (with ratios of principal values attaining 2 and more), the results of measurements agree very well among the different methods. The discrepancy for measurements along the foliation is negligible (<1%). The component of thermal conductivity normal to the foliation reveals somewhat larger differences (3-4%). Optical scanning allowed us to characterize the thermal inhomogeneity of rocks and to identify a three-dimensional anisotropy in thermal conductivity of some gneiss samples. The merits of optical scanning include minor random errors (1.6%), the ability to record the variation of thermal conductivity along the sample, the ability to sample deeply using a slow scanning rate, freedom from constraints for sample size and shape, and quality of mechanical treatment of the sample surface, a contactless mode of measurement, high speed of operation, and the ability to measure on a cylindrical sample surface. More traditional methods remain superior for characterizing bulk conductivity at elevated temperature.Three laboratory methods including divided-bar, line-source and optical scanning are widely applied in geothermal and petrophysical studies. In this study, these three methods were compared for determining the thermal conductivity tensor for anisotropic rocks

  18. Conformational and spectroscopic study of xanthogen ethyl formates, ROC(S)SC(O)OCH2CH3. Isolation of CH3CH2OC(O)SH

    NASA Astrophysics Data System (ADS)

    Juncal, Luciana C.; Cozzarín, Melina V.; Romano, Rosana M.

    2015-03-01

    ROC(S)SC(O)OCH2CH3, with R = CH3sbnd , (CH3)2CHsbnd and CH3(CH2)2sbnd , were obtained through the reaction between potassium xanthate salts, ROC(S)SK, and ethyl chloroformate, ClC(O)OCH2CH3. The liquid compounds were identified and characterized by 1H and 13C NMR and mass spectrometry. The conformations adopted by the molecules were studied by DFT methods. 6 conformers were theoretically predicted for R = CH3sbnd and (CH3)2CHsbnd , while the conformational flexibility of the n-propyl substituent increases the total number of feasible rotamers to 21. For the three molecules, the conformers can be associated in 3 groups, being the most stable the AS forms - the Cdbnd S double bond anti (A) with respect to the Csbnd S single bond and the Ssbnd C single bond syn (S) with respect to the Cdbnd O double bond - followed by AA and SS conformers. The vibrational spectra were interpreted in terms of the predicted conformational equilibrium, presenting the ν(Cdbnd O) spectral region signals corresponding to the three groups of conformers. A moderated pre-resonance Raman enhancement of the ν(Cdbnd S) vibrational mode of CH3(CH2)2OC(S)SC(O)OCH2CH3 was detected, when the excitation radiation approaches the energy of a n → π∗ electronic transition associated with the Cdbnd S chromophore. UV-visible spectra in different solvents were measured and interpreted in terms of TD-DFT calculations. The unknown molecule CH3CH2OC(O)SH was isolated by the UV-visible photolysis of CH3OC(S)SC(O)OCH2CH3 isolated in Ar matrix, and also obtained as a side-product of the reaction between potassium xanthate salts, ROC(S)SK, and ethyl chloroformate, ClC(O)OCH2CH3.

  19. Thermal decomposition of ethanol. 4. Ab initio chemical kinetics for reactions of H atoms with CH3CH2O and CH3CHOH radicals.

    PubMed

    Xu, Z F; Xu, Kun; Lin, M C

    2011-04-21

    The potential energy surfaces of H-atom reactions with CH(3)CH(2)O and CH(3)CHOH, two major radicals in the decomposition and oxidation of ethanol, have been studied at the CCSD(T)/6-311+G(3df,2p) level of theory with geometric optimization carried out at the BH&HLYP/6-311+G(3df,2p) level. The direct hydrogen abstraction channels and the indirect association/decomposition channels from the chemically activated ethanol molecule have been considered for both reactions. The rate constants for both reactions have been calculated at 100-3000 K and 10(-4) Torr to 10(3) atm Ar pressure by microcanonical VTST/RRKM theory with master equation solution for all accessible product channels. The results show that the major product channel of the CH(3)CH(2)O + H reaction is CH(3) + CH(2)OH under atmospheric pressure conditions. Only at high pressure and low temperature, the rate constant for CH(3)CH(2)OH formation by collisonal deactivation becomes dominant. For CH(3)CHOH + H, there are three major product channels; at high temperatures, CH(3)+CH(2)OH production predominates at low pressures (P < 100 Torr), while the formation of CH(3)CH(2)OH by collisional deactivation becomes competitive at high pressures and low temperatures (T < 500 K). At high temperatures, the direct hydrogen abstraction reaction producing CH(2)CHOH + H(2) becomes dominant. Rate constants for all accessible product channels in both systems have been predicted and tabulated for modeling applications. The predicted value for CH(3)CHOH + H at 295 K and 1 Torr pressure agrees closely with available experimental data. For practical modeling applications, the rate constants for the thermal unimolecular decomposition of ethanol giving key accessible products have been predicted; those for the two major product channels taking place by dehydration and C-C breaking agree closely with available literature data.

  20. Speciated Monitoring of Gas-Phase Organic Peroxy Radicals by Chemical Ionization Mass Spectrometry: Cross-Reactions between CH3O2, CH3(CO)O2, (CH3)3CO2, and c-C6H11O2.

    PubMed

    Nozière, Barbara; Hanson, David R

    2017-11-09

    Organic peroxy radicals ("RO 2 ", with R organic) are key intermediates in most oxygen-rich systems, where organic compounds are oxidized (natural environment, flames, combustion engines, living organisms, etc). But, until recently, techniques able to monitor simultaneously and distinguish between RO 2 species ("speciated" detection) have been scarce, which has limited the understanding of complex systems containing these radicals. Mass spectrometry using proton transfer ionization has been shown previously to detect individual gas-phase RO 2 separately. In this work, we illustrate its ability to speciate and monitor several RO 2 simultaneously by investigating reactions involving CH 3 O 2 , CH 3 C(O)O 2 , c-C 6 H 11 O 2 , and (CH 3 ) 3 CO 2 . The detection sensitivity of each of these radicals was estimated by titration with NO to between 50 and 1000 Hz/ppb, with a factor from 3 to 5 of uncertainties, mostly due to the uncertainties in knowing the amounts of added NO. With this, the RO 2 concentration in the reactor was estimated between 1 × 10 10 and 1 × 10 12 molecules cm -3 . When adding a second radical species to the reactor, the kinetics of the cross-reaction could be studied directly from the decay of the first radical. The time-evolution of two and sometimes three different RO 2 was followed simultaneously, as the CH 3 O 2 produced in further reaction steps was also detected in some systems. The rate coefficients obtained are (in molecule -1 cm 3 s -1 ): k CH3O2+CH3C(O)O2 = 1.2 × 10 -11 , k CH3O2+t-butylO2 = 3.0 × 10 -15 , k c-hexylO2+CH3O2 = 1.2 × 10 -13 , k t-butylO2+CH3C(O)O2 = 3.7 × 10 -14 , and k c-hexylO2+t-butylO2 = 1.5 × 10 -15 . In spite of their good comparison with the literature and good reproducibility, large uncertainties (×5/5) are recommended on these results because of those in the detection sensitivities. This work is a first illustration of the potential applications of this technique for the investigation of organic radicals in

  1. Ab Initio Chemical Kinetics for the CH3 + O((3)P) Reaction and Related Isomerization-Decomposition of CH3O and CH2OH Radicals.

    PubMed

    Xu, Z F; Raghunath, P; Lin, M C

    2015-07-16

    The kinetics and mechanism of the CH3 + O reaction and related isomerization-decomposition of CH3O and CH2OH radicals have been studied by ab initio molecular orbital theory based on the CCSD(T)/aug-cc-pVTZ//CCSD/aug-cc-pVTZ, CCSD/aug-cc-pVDZ, and G2M//B3LYP/6-311+G(3df,2p) levels of theory. The predicted potential energy surface of the CH3 + O reaction shows that the CHO + H2 products can be directly generated from CH3O by the TS3 → LM1 → TS7 → LM2 → TS4 path, in which both LM1 and LM2 are very loose and TS7 is roaming-like. The result for the CH2O + H reaction shows that there are three low-energy barrier processes including CH2O + H → CHO + H2 via H-abstraction and CH2O + H → CH2OH and CH2O + H → CH3O by addition reactions. The predicted enthalpies of formation of the CH2OH and CH3O radicals at 0 K are in good agreement with available experimental data. Furthermore, the rate constants for the forward and some key reverse reactions have been predicted at 200-3000 K under various pressures. Based on the new reaction pathway for CH3 + O, the rate constants for the CH2O + H and CHO + H2 reactions were predicted with the microcanonical variational transition-state/Rice-Ramsperger-Kassel-Marcus (VTST/RRKM) theory. The predicted total and individual product branching ratios (i.e., CO versus CH2O) are in good agreement with experimental data. The rate constant for the hydrogen abstraction reaction of CH2O + H has been calculated by the canonical variational transition-state theory with quantum tunneling and small-curvature corrections to be k(CH2O + H → CHO + H2) = 2.28 × 10(-19) T(2.65) exp(-766.5/T) cm(3) molecule(-1) s(-1) for the 200-3000 K temperature range. The rate constants for the addition giving CH3O and CH2OH and the decomposition of the two radicals have been calculated by the microcanonical RRKM theory with the time-dependent master equation solution of the multiple quantum well system in the 200-3000 K temperature range at 1 Torr to

  2. High Speed Videometric Monitoring of Rock Breakage

    NASA Astrophysics Data System (ADS)

    Allemand, J.; Shortis, M. R.; Elmouttie, M. K.

    2018-05-01

    Estimation of rock breakage characteristics plays an important role in optimising various industrial and mining processes used for rock comminution. Although little research has been undertaken into 3D photogrammetric measurement of the progeny kinematics, there is promising potential to improve the efficacy of rock breakage characterisation. In this study, the observation of progeny kinematics was conducted using a high speed, stereo videometric system based on laboratory experiments with a drop weight impact testing system. By manually tracking individual progeny through the captured video sequences, observed progeny coordinates can be used to determine 3D trajectories and velocities, supporting the idea that high speed video can be used for rock breakage characterisation purposes. An analysis of the results showed that the high speed videometric system successfully observed progeny trajectories and showed clear projection of the progeny away from the impact location. Velocities of the progeny could also be determined based on the trajectories and the video frame rate. These results were obtained despite the limitations of the photogrammetric system and experiment processes observed in this study. Accordingly there is sufficient evidence to conclude that high speed videometric systems are capable of observing progeny kinematics from drop weight impact tests. With further optimisation of the systems and processes used, there is potential for improving the efficacy of rock breakage characterisation from measurements with high speed videometric systems.

  3. Density and velocity relationships for digital sonic and density logs from coastal Washington and laboratory measurements of Olympic Peninsula mafic rocks and greywackes

    USGS Publications Warehouse

    Brocher, Thomas M.; Christensen, Nikolas I.

    2001-01-01

    for each well log. We also present two-way traveltimes for 15 of the wells calculated from the sonic velocities. Average velocities and densities for the wells having both logs can be reasonably well related using a modified Gardner’s rule, with p=1825v1/4, where p is the density (in kg/m3) and v is the sonic velocity (in km/s). In contrast, a similar analysis of published well logs from Puget Lowland is best matched by a Gardner’s rule of p=1730v1/4, close to the p=1740v1/4 proposed by Gardner et al. (1974). Finally, we present laboratory measurements of compressional-wave velocity, shear-wave velocity, and density for 11 greywackes and 29 mafic rocks from the Olympic Peninsula and Puget Lowland. These units have significance for earthquake-hazard investigations in Puget Lowland as they dip eastward beneath the Lowland, forming the “bedrock” beneath much of the lowland. Average Vp/Vs ratios for the mafic rocks, mainly Crescent Formation volcanics, lie between 1.81 and 1.86. Average Vp/Vs ratios for the greywackes from the accretionary core complex in the Olympic Peninsula show greater scatter but lie between 1.77 and 1.88. Both the Olympic Peninsula mafic rocks and greywackes have lower shear-wave velocities than would be expected for a Poisson solid (Vp/Vs=1.732). Although the P-wave velocities and densities in the greywackes can be related by a Gardner’s rule of p=1720v1/4, close to the p=1740v1/4 proposed by Gardner et al. (1974), the velocities and densities of the mafic rocks are best related by a Gardner’s rule of p=1840v1/4. Thus, the density/velocity relations are similar for the Puget Lowland well logs and greywackes from the Olympic Peninsula. Density/velocity relations are similar for the Washington coastal well logs and mafic rocks from the Olympic Peninsula, but differ from those of the Puget Lowland well logs and greywackes from the Olympic Peninsula.

  4. Quantification of parameters influencing methane generation due to biodegradation of municipal solid waste in landfills and laboratory experiments.

    PubMed

    Fei, Xunchang; Zekkos, Dimitrios; Raskin, Lutgarde

    2016-09-01

    The energy conversion potential of municipal solid waste (MSW) disposed of in landfills remains largely untapped because of the slow and variable rate of biogas generation, delayed and inefficient biogas collection, leakage of biogas, and landfill practices and infrastructure that are not geared toward energy recovery. A database consisting of methane (CH4) generation data, the major constituent of biogas, from 49 laboratory experiments and field monitoring data from 57 landfills was developed. Three CH4 generation parameters, i.e., waste decay rate (k), CH4 generation potential (L0), and time until maximum CH4 generation rate (tmax), were calculated for each dataset using U.S. EPA's Landfill Gas Emission Model (LandGEM). Factors influencing the derived parameters in laboratory experiments and landfills were investigated using multi-linear regression analysis. Total weight of waste (W) was correlated with biodegradation conditions through a ranked classification scheme. k increased with increasing percentage of readily biodegradable waste (Br0 (%)) and waste temperature, and reduced with increasing W, an indicator of less favorable biodegradation conditions. The values of k obtained in the laboratory were commonly significantly higher than those in landfills and those recommended by LandGEM. The mean value of L0 was 98 and 88L CH4/kg waste for laboratory and field studies, respectively, but was significantly affected by waste composition with ranges from 10 to 300L CH4/kg. tmax increased with increasing percentage of biodegradable waste (B0) and W. The values of tmax in landfills were higher than those in laboratory experiments or those based on LandGEM's recommended parameters. Enhancing biodegradation conditions in landfill cells has a greater impact on improving k and tmax than increasing B0. Optimizing the B0 and Br0 values of landfilled waste increases L0 and reduces tmax. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Electron spin resonance of (CO 2 H)CH 2 CH 2 CH(CO 2 H) in irradiated glutaric acid

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Horsfield, A.; Morton, J. R.; Whiffen, D. H.

    It is concluded from electron spin resonance spectra that the radical (CO 2 H)CH 2 CH 2 CH(CO 2 H) remains trapped in a glutaric acid crystal after gamma -irradiation. This radical is found in two different conformations. Approximate hyperfine coupling constants are given for each, although exact interpretation is hindered by the overlapping of spectra. Reasons for the formation of the two forms of the radical are discussed.

  6. Laboratory measurements of reservoir rock from the Geysers geothermal field, California

    USGS Publications Warehouse

    Lockner, D.A.; Summers, R.; Moore, D.; Byerlee, J.D.

    1982-01-01

    Rock samples taken from two outcrops, as well as rare cores from three well bores at the Geysers geothermal field, California, were tested at temperatures and pressures similar to those found in the geothermal field. Both intact and 30?? sawcut cylinders were deformed at confining pressures of 200-1000 bars, pore pressure of 30 bars and temperatures of 150?? and 240??C. Thin-section and X-ray analysis revealed that some borehole samples had undergone extensive alteration and recrystallization. Constant strain rate tests of 10-4 and 10-6 per sec gave a coefficient of friction of 0.68. Due to the highly fractured nature of the rocks taken from the production zone, intact samples were rarely 50% stronger than the frictional strength. This result suggests that the Geysers reservoir can support shear stresses only as large as its frictional shear strength. Velocity of p-waves (6.2 km/sec) was measured on one sample. Acoustic emission and sliding on a sawcut were related to changes in pore pressure. b-values computed from the acoustic emissions generated during fluid injection were typically about 0.55. An unusually high b-value (approximately 1.3) observed during sudden injection of water into the sample may have been related to thermal cracking. ?? 1982.

  7. On the formation of the ·CH 2CH 2CH=NH 2+ distonic radical cation upon ionization of cyclopropylamine and allylamine

    NASA Astrophysics Data System (ADS)

    Nguyen, Minh Tho; Creve, Steven; Ha, Tae-Kyu

    1998-08-01

    Ab initio molecular orbital and density functional theory calculations have been applied to determine the relative stability of the cyclopropylamine 1 and allylamine (CH 2=CHCH 2NH 2+·2) radical cations and their isomers. It is confirmed that, upon ionization, 1 undergoes barrier-free ring-opening giving the distonic species ·CH 2CH 2CH=NH 2+3. 2 also rearranges by a 1,2-H-shift to the more stable 3 (by 70 kJ/mol) which is, however, less stable than the 1-aminopropene ion (CH 3-CH=CH-NH 2+·4) by 60 kJ/mol. The transition structure TS 2/3 lies 40 kJ/mol higher in energy than TS 3/4. Although QCISD and B3LYP calculations of isotropic hyperfine coupling constants agree reasonably with observed values, supporting the presence of the distonic 3 in ESR matrix experiments, the exclusive observation of 3, but not 4, is intriguing. This emphasizes the role of the matrix in stabilizing 3.

  8. Kinetic conversion of CO to CH4 in the Solar System

    NASA Technical Reports Server (NTRS)

    Yung, Y. L.; Allen, M.; Pinto, J. P.

    1991-01-01

    Some of the most interesting chemistry in the Solar System involves changes in the oxidation state of the simple carbon species. The chemical pathways for the conversion of CH4 to CO and CO2 are for the most part known. The reverse process, the reduction of CO to CH4, is, however, poorly understood. This is surprising in view of the importance of the reduction process in the chemistry of the Solar System. Recently we investigated the chemical kinetics of a hitherto unsuspected reaction. It is argued that the formation of the methoxy radical (CH3O) from H+H2CO may play an essential role in the reduction of CO to CH4. The rate coefficient for this reaction has been estimated using the approximate theory of J. Troe and transition state theory. We will discuss the implications of this reaction for the chemistry of CO on Jupiter, in the solar nebula, for interpreting the laboratory experiments of A. Bar-Nun and A. Shaviv and A. Bar-Nun and S. Chang, and for organic synthesis in the prebiotic terrestrial atmosphere. The possible relation of CO reduction in the solar nebula and polyoxymethylene observed in comet Halley will be discussed.

  9. Laboratory-scale measurements of N2O and CH4 emissions from hybrid poplars (Populus deltoides x Populus nigra).

    PubMed

    McBain, M C; Warland, J S; McBride, R A; Wagner-Riddle, C

    2004-12-01

    The purpose of this study was to determine whether or not young hybrid poplar (Populus deltoides x Populus nigra) could transport landfill biogas internally from the root zone to the atmosphere, thereby acting as conduits for landfill gas release. Fluxes of methane (CH4) and nitrous oxide (N2O) from the seedlings to the atmosphere were measured under controlled conditions using dynamic flux chambers and a tunable diode laser trace gas analyser (TDLTGA). Nitrous oxide was emitted from the seedlings, but only when extremely high soil N2O concentrations were applied to the root zone. In contrast, no detectable emissions of CH4 were measured in a similar experimental trial. Visible plant morphological responses, characteristic of flood-tolerant trees attempting to cope with the negative effects of soil hypoxia, were observed during the CH4 experiments. Leaf chlorosis, leaf abscission and adventitious roots were all visible plant responses. In addition, seedling survival was observed to be highest in the biogas 'hot spot' areas of a local municipal solid waste landfill involved in this study. Based on the available literature, these observations suggest that CH4 can be transported internally by Populus deltoides x Populus nigra seedlings in trace amounts, although future research is required to fully test this hypothesis.

  10. Rate Constants for the Reactions of OH with CH(sub 3)Cl, CH(sub 2) C1(sub 2), CHC1(sub 3)and CH(sub 3)Br

    NASA Technical Reports Server (NTRS)

    Hsu, H-J.; DeMore, W.

    1994-01-01

    Rate constants for the reactions of OH with CH3C1, CH2Cl2, CHCl3 and CH3Br have been measured by a relative rate technique in which the reaction rate of each compound was compared to that of HFC-152a (CH3CHF2)and for CH2Cl2, HFC-161 (CH3CH2F).

  11. SeqBox: RNAseq/ChIPseq reproducible analysis on a consumer game computer.

    PubMed

    Beccuti, Marco; Cordero, Francesca; Arigoni, Maddalena; Panero, Riccardo; Amparore, Elvio G; Donatelli, Susanna; Calogero, Raffaele A

    2018-03-01

    Short reads sequencing technology has been used for more than a decade now. However, the analysis of RNAseq and ChIPseq data is still computational demanding and the simple access to raw data does not guarantee results reproducibility between laboratories. To address these two aspects, we developed SeqBox, a cheap, efficient and reproducible RNAseq/ChIPseq hardware/software solution based on NUC6I7KYK mini-PC (an Intel consumer game computer with a fast processor and a high performance SSD disk), and Docker container platform. In SeqBox the analysis of RNAseq and ChIPseq data is supported by a friendly GUI. This allows access to fast and reproducible analysis also to scientists with/without scripting experience. Docker container images, docker4seq package and the GUI are available at http://www.bioinformatica.unito.it/reproducibile.bioinformatics.html. beccuti@di.unito.it. Supplementary data are available at Bioinformatics online. © The Author(s) 2017. Published by Oxford University Press.

  12. 3-D Printing as a Tool to Investigate the Effects of Changes in Rock Microstructures on Permeability

    NASA Astrophysics Data System (ADS)

    Head, D. A.; Vanorio, T.

    2016-12-01

    Rocks are naturally heterogeneous; two rock samples with identical bulk properties can vary widely in microstructure. Understanding the evolutionary trends of rock properties requires the ability to connect time-lapse measurements of properties at different scales: the macro- scale used in the laboratory and field analyses capturing the bulk scale changes and the micro- scale used in imaging and digital techniques capturing the changes to the pore space. However, measuring those properties at different scales is very challenging, and sometimes impossible. The advent of modern 3D printing has provided an unprecedented opportunity to link those scales by combining the strengths of digital and experimental rock physics. To determine the feasibility of this technique we characterized the resolution capabilities of two different 3D printers. To calibrate our digital models with our printed models, we created a sample with an analytically solvable permeability. This allowed us to directly compare analytic calculation, numerical simulation, and laboratory measurement of permeability of the exact same sample. Next we took a CT-scanned model of a natural carbonate pore space, then iteratively digitally manipulated, 3D printed, and measured the flow properties in the laboratory. This approach allowed us to access multiple scales digitally and experimentally, to test hypotheses about how changes in rock microstructure due to compaction and dissolution affect bulk transport properties, and to connect laboratory measurements of porosity and permeability to quantities that are traditionally impossible to measure in the laboratory such as changes in surface area and tortuosity. As 3D printing technology continues to advance, we expect this technique to contribute to our ability to characterize the properties of remote and/or delicate samples as well as to test the impact of microstructural alteration on bulk physical properties in the lab in a highly consistent, repeatable manner.

  13. Unusual reaction paths of SN2 nucleophile substitution reactions CH4 + H- → CH4 + H- and CH4 + F- → CH3F + H-: Quantum chemical calculations

    NASA Astrophysics Data System (ADS)

    Minyaev, Ruslan M.; Quapp, Wolfgang; Schmidt, Benjamin; Getmanskii, Ilya V.; Koval, Vitaliy V.

    2013-11-01

    Quantum chemical (CCSD(full)/6-311++G(3df,3pd), CCSD(T)(full)/6-311++G(3df,3pd)) and density function theory (B3LYP/6-311++G(3df,3pd)) calculations were performed for the SN2 nucleophile substitution reactions CH4 + H- → CH4 + H- and CH4 + F- → CH3F + H-. The calculated gradient reaction pathways for both reactions have an unusual behavior. An unusual stationary point of index 2 lies on the gradient reaction path. Using Newton trajectories for the reaction path, we can detect VRI point at which the reaction path branches.

  14. Rock Moved by Mars Lander Arm, Stereo View

    NASA Technical Reports Server (NTRS)

    2008-01-01

    The robotic arm on NASA's Phoenix Mars Lander slid a rock out of the way during the mission's 117th Martian day (Sept. 22, 2008) to gain access to soil that had been underneath the rock.The lander's Surface Stereo Imager took the two images for this stereo view later the same day, showing the rock, called 'Headless,' after the arm pushed it about 40 centimeters (16 inches) from its previous location.

    'The rock ended up exactly where we intended it to,' said Matt Robinson of NASA's Jet Propulsion Laboratory, robotic arm flight software lead for the Phoenix team.

    The arm had enlarged the trench near Headless two days earlier in preparation for sliding the rock into the trench. The trench was dug to about 3 centimeters (1.2 inches) deep. The ground surface between the rock's prior position and the lip of the trench had a slope of about 3 degrees downward toward the trench. Headless is about the size and shape of a VHS videotape.

    The Phoenix science team sought to move the rock in order to study the soil and the depth to subsurface ice underneath where the rock had been.

    This left-eye and right-eye images for this stereo view were taken at about 12:30 p.m., local solar time on Mars. The scene appears three-dimensional when seen through blue-red glasses.The view is to the north northeast of the lander.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by JPL, Pasadena, Calif. Spacecraft development was by Lockheed Martin Space Systems, Denver.

  15. The role of fluids in rock layering development: a pressure solution self-organized process revealed by laboratory experiments

    NASA Astrophysics Data System (ADS)

    Gratier, Jean-Pierre; Noiriel, Catherine; Renard, Francois

    2015-04-01

    Natural deformation of rocks is often associated with stress-driven differentiation processes leading to irreversible transformations of their microstructures. The development mechanisms of such processes during diagenesis, tectonic, metamorphism or fault differentiation are poorly known as they are difficult to reproduce experimentally due to the very slow kinetics of stress-driven chemical processes. Here, we show that experimental compaction with development of differentiated layering, similar to what happens in natural deformation, can be obtained by indenter techniques in laboratory conditions. Samples of plaster mixed with clay and of diatomite loosely interbedded with volcanic dust were loaded in presence of their saturated aqueous solutions during several months at 40°C and 150°C, respectively. High-resolution X-ray microtomography and scanning electron microscopy observations show that the layering development is a pressure solution self-organized process. Stress-driven dissolution of the soluble minerals (either gypsum or silica) is initiated in the areas initially richer in insoluble minerals (clays or volcanic dust) because the kinetics of diffusive mass transfer along the soluble/insoluble mineral interfaces is much faster than along the healed boundaries of the soluble minerals. The passive concentration of insoluble minerals amplifies the localization of dissolution along some layers oriented perpendicular to the maximum compressive stress. Conversely, in the areas with initial low content in insoluble minerals and clustered soluble minerals, dissolution is slower. Consequently, these areas are less deformed, they host the re-deposition of the soluble species and they act as rigid objects that concentrate the dissolution near their boundaries thus amplifying the differentiation. A crucial parameter required for self-organized process of pressure solution is the presence of a fluid that is a good solvent of at least some of the rock-forming minerals

  16. Tests of stratospheric models - The reactions of atomic chlorine with O3 and CH4 at low temperature

    NASA Technical Reports Server (NTRS)

    Demore, W. B.

    1991-01-01

    The rate-constant ratio of the photochemical reactions of atomic chlorine with O3 and CH4 was determined using data from laboratory experiments on competitive chlorination of O3/CH4 mixtures at stratospheric temperatures (197-217 K). Two experimental approaches were used: (1) measuring the k1/k2 ratio for the reactions of atomic chlorine with ozone and methane and (2) testing for some of the ClO/CH3O2 chemistry. The chlorine and ozone concentrations were monitored by UV-Vis spectroscopy, and the CH3Cl concentration was measured by FTIR. The results on the k1/k2 ratio are in excellent agreement with the current NASA recommendation (DeMore et al., 1990), being only 12 percent higher. On the other hand, results on the ClO + CH3O2 reaction do not support the rate constant suggested by Simon et al. (1989).

  17. Uniaxial Compressive Strengths of Rocks Drilled at Gale Crater, Mars

    NASA Astrophysics Data System (ADS)

    Peters, G. H.; Carey, E. M.; Anderson, R. C.; Abbey, W. J.; Kinnett, R.; Watkins, J. A.; Schemel, M.; Lashore, M. O.; Chasek, M. D.; Green, W.; Beegle, L. W.; Vasavada, A. R.

    2018-01-01

    Measuring the physical properties of geological materials is important for understanding geologic history. Yet there has never been an instrument with the purpose of measuring mechanical properties of rocks sent to another planet. The Mars Science Laboratory (MSL) rover employs the Powder Acquisition Drill System (PADS), which provides direct mechanical interaction with Martian outcrops. While the objective of the drill system is not to make scientific measurements, the drill's performance is directly influenced by the mechanical properties of the rocks it drills into. We have developed a methodology that uses the drill to indicate the uniaxial compressive strengths of rocks through comparison with performance of an identically assembled drill system in terrestrial samples of comparable sedimentary class. During this investigation, we utilize engineering data collected on Mars to calculate the percussive energy needed to maintain a prescribed rate of penetration and correlate that to rock strength.

  18. Rock sample brought to earth from the Apollo 12 lunar landing mission

    NASA Image and Video Library

    1969-12-04

    S69-60909 (November 1969) --- A close-up view of lunar sample 12,052 under observation in the Manned Spacecraft Center's Lunar Receiving Laboratory (LRL). Astronauts Charles Conrad Jr., and Alan L. Bean collected several rocks and samples of finer lunar matter during their Apollo 12 lunar landing mission extravehicular activity (EVA). This particular sample was picked up during the second space walk (EVA) on Nov. 20, 1969. It is a typically fine-grained crystalline rock with a concentration of holes on the left part of the exposed side. These holes are called vesicles and have been identified as gas bubbles formed during the crystallization of the rock. Several glass-lined pits can be seen on the surface of the rock.

  19. Reflected shock tube studies of high-temperature rate constants for OH + CH4 --> CH3 + H2O and CH3 + NO2 --> CH3O + NO.

    PubMed

    Srinivasan, N K; Su, M-C; Sutherland, J W; Michael, J V

    2005-03-10

    The reflected shock tube technique with multipass absorption spectrometric detection of OH radicals at 308 nm has been used to study the reactions OH + CH(4) --> CH(3) + H(2)O and CH(3) + NO(2) --> CH(3)O + NO. Over the temperature range 840-2025 K, the rate constants for the first reaction can be represented by the Arrhenius expression k = (9.52 +/- 1.62) x 10(-11) exp[(-4134 +/- 222 K)/T] cm(3) molecule(-1) s(-1). Since this reaction is important in both combustion and atmospheric chemistry, there have been many prior investigations with a variety of techniques. The present results extend the temperature range by 500 K and have been combined with the most accurate earlier studies to derive an evaluation over the extended temperature range 195-2025 K. A three-parameter expression describes the rate behavior over this temperature range, k = (1.66 x 10(-18))T(2.182) exp[(-1231 K)/T] cm(3) molecule(-1) s(-1). Previous theoretical studies are discussed, and the present evaluation is compared to earlier theoretical estimates. Since CH(3) radicals are a product of the reaction and could cause secondary perturbations in rate constant determinations, the second reaction was studied by OH radical production from the fast reactions CH(3)O --> CH(2)O + H and H + NO(2) --> OH + NO. The measured rate constant is 2.26 x 10(-11) cm(3) molecule(-1) s(-1) and is not dependent on temperature from 233 to 1700 K within experimental error.

  20. Observing and modeling links between soil moisture, microbes and CH4 fluxes from forest soils

    NASA Astrophysics Data System (ADS)

    Christiansen, Jesper; Levy-Booth, David; Barker, Jason; Prescott, Cindy; Grayston, Sue

    2017-04-01

    Soil moisture is a key driver of methane (CH4) fluxes in forest soils, both of the net uptake of atmospheric CH4 and emission from the soil. Climate and land use change will alter spatial patterns of soil moisture as well as temporal variability impacting the net CH4 exchange. The impact on the resultant net CH4 exchange however is linked to the underlying spatial and temporal distribution of the soil microbial communities involved in CH4 cycling as well as the response of the soil microbial community to environmental changes. Significant progress has been made to target specific CH4 consuming and producing soil organisms, which is invaluable in order to understand the microbial regulation of the CH4 cycle in forest soils. However, it is not clear as to which extent soil moisture shapes the structure, function and abundance of CH4 specific microorganisms and how this is linked to observed net CH4 exchange under contrasting soil moisture regimes. Here we report on the results from a research project aiming to understand how the CH4 net exchange is shaped by the interactive effects soil moisture and the spatial distribution CH4 consuming (methanotrophs) and producing (methanogens). We studied the growing season variations of in situ CH4 fluxes, microbial gene abundances of methanotrophs and methanogens, soil hydrology, and nutrient availability in three typical forest types across a soil moisture gradient in a temperate rainforest on the Canadian Pacific coast. Furthermore, we conducted laboratory experiments to determine whether the net CH4 exchange from hydrologically contrasting forest soils responded differently to changes in soil moisture. Lastly, we modelled the microbial mediation of net CH4 exchange along the soil moisture gradient using structural equation modeling. Our study shows that it is possible to link spatial patterns of in situ net exchange of CH4 to microbial abundance of CH4 consuming and producing organisms. We also show that the microbial

  1. Purdue Rare Isotope Measurement Laboratory

    NASA Astrophysics Data System (ADS)

    Caffee, M.; Elmore, D.; Granger, D.; Muzikar, P.

    2002-12-01

    The Purdue Rare Isotope Measurement Laboratory (PRIME Lab) is a dedicated research and service facility for accelerator mass spectrometry. AMS is an ultra-sensitive analytical technique used to measure low levels of long-lived cosmic-ray-produced and anthropogenic radionuclides, and rare trace elements. We measure 10Be (T1/2 = 1.5 My), 26Al (.702 My), 36Cl (.301 My), and 129I (16 My), in geologic samples. Applications include dating the cosmic-ray-exposure time of rocks on Earth's surface, determining rock and sediment burial ages, measuring the erosion rates of rocks and soils, and tracing and dating ground water. We perform sample preparation and separation chemistries for these radio-nuclides for our internal research activities and for those external researchers not possessing this capability. Our chemical preparation laboratories also serve as training sites for members of the geoscience community developing these techniques at their institutions. Research at Purdue involves collaborators among members of the Purdue Departments of Physics, Earth and Atmospheric Sciences, Chemistry, Agronomy, and Anthropology. We also collaborate and serve numerous scientists from other institutions. We are currently in the process of modernizing the facility with the goals of higher precision for routinely measured radio-nuclides, increased sample throughput, and the development of new measurement capabilities for the geoscience community.

  2. Airborne Proximity Warning Instrument Laboratory Tests

    DOT National Transportation Integrated Search

    1977-01-01

    An Airborne Proximity Warning Instrument (APWI) designed and manufactured by Rock Avionics, New York, was subjected to a short laboratory test at the Transportation Systems Center to determine the suitability of this product for further evaluation as...

  3. The origin of granites and related rocks

    USGS Publications Warehouse

    Brown, Michael; Piccoli, Philip M.

    1995-01-01

    This Circular is a compilation of abstracts for posters and oral presentations given at the third Hutton symposium on the Origin of granites and related rocks. The symposium was co-sponsored by the Department of Geology, University of Maryland at College Park; the U.S. Geological Survey, Reston, Virginia; and the Department of Terrestrial Magnetism and Geophysical Laboratory, Carnegie Institution of Washington.

  4. Local- and regional-scale measurements of CH4, δ13CH4, and C2H6 in the Uintah Basin using a mobile stable isotope analyzer

    NASA Astrophysics Data System (ADS)

    Rella, C. W.; Hoffnagle, J.; He, Y.; Tajima, S.

    2015-10-01

    In this paper, we present an innovative CH4, δ13CH4, and C2H6 instrument based on cavity ring-down spectroscopy (CRDS). The design and performance of the analyzer is presented in detail. The instrument is capable of precision of less than 1 ‰ on δ13CH4 with 1 in. of averaging and about 0.1 ‰ in an hour. Using this instrument, we present a comprehensive approach to atmospheric methane emissions attribution. Field measurements were performed in the Uintah Basin (Utah, USA) in the winter of 2013, using a mobile lab equipped with the CRDS analyzer, a high-accuracy GPS, a sonic anemometer, and an onboard gas storage and playback system. With a small population and almost no other sources of methane and ethane other than oil and gas extraction activities, the Uintah Basin represents an ideal location to investigate and validate new measurement methods of atmospheric methane and ethane. We present the results of measurements of the individual fugitive emissions from 23 natural gas wells and six oil wells in the region. The δ13CH4 and C2H6 signatures that we observe are consistent with the signatures of the gases found in the wells. Furthermore, regional measurements of the atmospheric CH4, δ13CH4, and C2H6 signatures throughout the basin have been made, using continuous sampling into a 450 m long tube and laboratory reanalysis with the CRDS instrument. These measurements suggest that 85 ± 7 % of the total emissions in the basin are from natural gas production.

  5. Rock Formation and Cosmic Radiation Exposure Ages in Gale Crater Mudstones from the Mars Science Laboratory

    NASA Astrophysics Data System (ADS)

    Mahaffy, Paul; Farley, Ken; Malespin, Charles; Gellert, Ralph; Grotzinger, John

    2014-05-01

    The quadrupole mass spectrometer (QMS) in the Sample Analysis at Mars (SAM) suite of the Mars Science Laboratory (MSL) has been utilized to secure abundances of 3He, 21Ne, 36Ar, and 40Ar thermally evolved from the mudstone in the stratified Yellowknife Bay formation in Gale Crater. As reported by Farley et al. [1] these measurements of cosmogenic and radiogenic noble gases together with Cl and K abundances measured by MSL's alpha particle X-ray spectrometer enable a K-Ar rock formation age of 4.21+0.35 Ga to be established as well as a surface exposure age to cosmic radiation of 78+30 Ma. Understanding surface exposures to cosmic radiation is relevant to the MSL search for organic compounds since even the limited set of studies carried out, to date, indicate that even 10's to 100's of millions of years of near surface (1-3 meter) exposure may transform a significant fraction of the organic compounds exposed to this radiation [2,3,4]. Transformation of potential biosignatures and even loss of molecular structural information in compounds that could point to exogenous or endogenous sources suggests a new paradigm in the search for near surface organics that incorporates a search for the most recently exposed outcrops through erosional processes. The K-Ar rock formation age determination shows promise for more precise in situ measurements that may help calibrate the martian cratering record that currently relies on extrapolation from the lunar record with its ground truth chronology with returned samples. We will discuss the protocol for the in situ noble gas measurements secured with SAM and ongoing studies to optimize these measurements using the SAM testbed. References: [1] Farley, K.A.M Science Magazine, 342, (2013). [2] G. Kminek et al., Earth Planet Sc Lett 245, 1 (2006). [3] Dartnell, L.R., Biogeosciences 4, 545 (2007). [4] Pavlov, A. A., et al. Geophys Res Lett 39, 13202 (2012).

  6. Rock pushing and sampling under rocks on Mars

    USGS Publications Warehouse

    Moore, H.J.; Liebes, S.; Crouch, D.S.; Clark, L.V.

    1978-01-01

    Viking Lander 2 acquired samples on Mars from beneath two rocks, where living organisms and organic molecules would be protected from ultraviolet radiation. Selection of rocks to be moved was based on scientific and engineering considerations, including rock size, rock shape, burial depth, and location in a sample field. Rock locations and topography were established using the computerized interactive video-stereophotogrammetric system and plotted on vertical profiles and in plan view. Sampler commands were developed and tested on Earth using a full-size lander and surface mock-up. The use of power by the sampler motor correlates with rock movements, which were by plowing, skidding, and rolling. Provenance of the samples was determined by measurements and interpretation of pictures and positions of the sampler arm. Analytical results demonstrate that the samples were, in fact, from beneath the rocks. Results from the Gas Chromatograph-Mass Spectrometer of the Molecular Analysis experiment and the Gas Exchange instrument of the Biology experiment indicate that more adsorbed(?) water occurs in samples under rocks than in samples exposed to the sun. This is consistent with terrestrial arid environments, where more moisture occurs in near-surface soil un- der rocks than in surrounding soil because the net heat flow is toward the soil beneath the rock and the rock cap inhibits evaporation. Inorganic analyses show that samples of soil from under the rocks have significantly less iron than soil exposed to the sun. The scientific significance of analyses of samples under the rocks is only partly evaluated, but some facts are clear. Detectable quantities of martian organic molecules were not found in the sample from under a rock by the Molecular Analysis experiment. The Biology experiments did not find definitive evidence for Earth-like living organisms in their sample. Significant amounts of adsorbed water may be present in the martian regolith. The response of the soil

  7. Rock Abrasion Tool Exhibits the Deep Red Pigment of Mars

    NASA Technical Reports Server (NTRS)

    2006-01-01

    During recent soil-brushing experiments, the rock abrasion tool on NASA's Mars Exploration Rover Spirit became covered with dust, as shown here. An abundance of iron oxide minerals in the dust gave the device a reddish-brown veneer. Investigators were using the rock abrasion tool to uncover successive layers of soil in an attempt to reveal near-surface stratigraphy. Afterward, remnant dirt clods were visible on both the bit and the brush of the tool. Designers of the rock abrasion tool at Honeybee Robotics and engineers at the Jet Propulsion Laboratory developed a plan to run the brush on the rock abrasion tool in reverse to dislodge the dirt and return the tool to normal operation. Subsequent communications with the rover revealed that the procedure is working and the rock abrasion tool remains healthy.

    Spirit acquired this approximately true-color image with the panoramic camera on the rover's 893rd sol, or Martian day (July 8, 2006). The image combines exposures taken through three of the camera's filters, centered on wavelengths of 750 nanometers, 530 nanometers, and 430 nanometers.

  8. Electric resistivity and seismic refraction tomography: a challenging joint underwater survey at Äspö Hard Rock Laboratory

    NASA Astrophysics Data System (ADS)

    Ronczka, Mathias; Hellman, Kristofer; Günther, Thomas; Wisén, Roger; Dahlin, Torleif

    2017-06-01

    Tunnelling below water passages is a challenging task in terms of planning, pre-investigation and construction. Fracture zones in the underlying bedrock lead to low rock quality and thus reduced stability. For natural reasons, they tend to be more frequent at water passages. Ground investigations that provide information on the subsurface are necessary prior to the construction phase, but these can be logistically difficult. Geophysics can help close the gaps between local point information by producing subsurface images. An approach that combines seismic refraction tomography and electrical resistivity tomography has been tested at the Äspö Hard Rock Laboratory (HRL). The aim was to detect fracture zones in a well-known but logistically challenging area from a measuring perspective. The presented surveys cover a water passage along part of a tunnel that connects surface facilities with an underground test laboratory. The tunnel is approximately 100 m below and 20 m east of the survey line and gives evidence for one major and several minor fracture zones. The geological and general test site conditions, e.g. with strong power line noise from the nearby nuclear power plant, are challenging for geophysical measurements. Co-located positions for seismic and ERT sensors and source positions are used on the 450 m underwater section of the 700 m profile. Because of a large transition zone that appeared in the ERT result and the missing coverage of the seismic data, fracture zones at the southern and northern parts of the underwater passage cannot be detected by separated inversion. Synthetic studies show that significant three-dimensional (3-D) artefacts occur in the ERT model that even exceed the positioning errors of underwater electrodes. The model coverage is closely connected to the resolution and can be used to display the model uncertainty by introducing thresholds to fade-out regions of medium and low resolution. A structural coupling cooperative inversion

  9. Total cross sections of electron scattering by molecules NF3, PF3, N(CH3)3, P(CH3)3, NH(CH3)2, PH(CH3)2, NH2CH3 and PH2CH3 at 30-5000 eV

    NASA Astrophysics Data System (ADS)

    Shi, D. H.; Sun, J. F.; Zhu, Z. L.; Liu, Y. F.

    2010-04-01

    Total cross sections of electron scattering by eight molecules NF3, PF3, N(CH3)3, P(CH3)3, NH(CH3)2, PH(CH3)2, NH2CH3 and PH2CH3, which have some structural similarities, are calculated at the Hartree-Fork level by the modified additivity rule approach [D.H. Shi, J.F. Sun, Z.L. Zhu, H. Ma, Y.F. Liu, Eur. Phys. J. D 45, 253 (2007); D.H. Shi, J.F. Sun, Y.F. Liu, Z.L. Zhu, X.D. Yang, Chin. Opt. Lett. 4, 192 (2006)]. The modified additivity rule approach takes into considerations that the contributions of the geometric shielding effect vary as the energy of incident electrons, the dimension of target molecule, the number of electrons in the molecule and the number of atoms constituting the molecule. The present investigations cover the impact energy range from 30 to 5000 eV. The quantitative total cross sections are compared with those obtained by experiments and other theories. Excellent agreement is observed even at energies of several tens of eV. It shows that the modified additivity rule approach is applicable to carry out the total cross section calculations of electron scattering by these molecules at intermediate and high energies, in particular over the energy range above 80 eV or so. It proves that the microscopic molecular properties, such as the geometrical size of the target and the number of atoms constituting the molecule, are of crucial importance in the TCS calculations. The new results for PH(CH3)2 and PH2CH3 are also presented at energies from 30 to 5000 eV, although no experimental and theoretical data are available for comparison. In the present calculations, the atoms are still represented by the spherical complex optical potential, which is composed of static, exchange, polarization and absorption terms.

  10. H atoms in CH4 and Xe matrices at cryogenic temperatures

    NASA Astrophysics Data System (ADS)

    Willard, J. E.

    1982-07-01

    Cryogenic techniques coupled with electron spin resonance detection methods have made it possible to produce long-lived trapped hydrogen atoms in inert matrices at 4 K and to study their reactions with neutral molecules and molecular fragments when the temperature is raised to the point where they diffuse. Under the matrix conditions H atoms abstract H rapidly from all carbon-hydrogen bonds (except those of CH 4) by quantum mechanical tunnelling, even though such reactions would be precluded if the classical activation energy prevailed. Thermal H atoms in CH 4 at 15 K add to CO to form the HCO radical, and to O 2 to form the HO 2 radical. When exposed to the appropriate wavelength of light these and other radicals, including CH 3, C 2H 5 and C 2H 3 lose H by photoelimination. The H atoms are produced in the matrices by X radiolysis, γ-ray radiolysis, or photolysis of a hydrogen halide. This paper reviews some of the most significant current findings in the field from different laboratories.

  11. Electron driven processes in sulphur containing compounds CH3SCH3 and CH3SSCH3

    NASA Astrophysics Data System (ADS)

    Kopyra, Janina; Władziński, Jakub

    2015-06-01

    Dissociative electron attachment to gas phase dimethyl sulphide (CH3SCH3) and dimethyl disulphide (CH3SSCH3) has been studied by means of a crossed beams apparatus. Cleavage of the C-S bond within CH3SCH3 and the S-S bond within CH3SSCH3 is observed within a resonance in the energy range below 2 eV and visible preferentially via the appearance of the fragment CH2S-. The striking finding is that the intensity of CH2S- generated from CH3SSCH3 is more than two orders of magnitude higher than the intensity of the respective anionic fragment generated from CH3SCH3. Our results clearly demonstrate that the CH3SSCH3 molecule, which contains disulphide bridge is substantially more sensitive towards electron attachment resulting mainly in dissociation along the S-S bridge.

  12. Imaging and computational considerations for image computed permeability: Operating envelope of Digital Rock Physics

    NASA Astrophysics Data System (ADS)

    Saxena, Nishank; Hows, Amie; Hofmann, Ronny; Alpak, Faruk O.; Freeman, Justin; Hunter, Sander; Appel, Matthias

    2018-06-01

    This study defines the optimal operating envelope of the Digital Rock technology from the perspective of imaging and numerical simulations of transport properties. Imaging larger volumes of rocks for Digital Rock Physics (DRP) analysis improves the chances of achieving a Representative Elementary Volume (REV) at which flow-based simulations (1) do not vary with change in rock volume, and (2) is insensitive to the choice of boundary conditions. However, this often comes at the expense of image resolution. This trade-off exists due to the finiteness of current state-of-the-art imaging detectors. Imaging and analyzing digital rocks that sample the REV and still sufficiently resolve pore throats is critical to ensure simulation quality and robustness of rock property trends for further analysis. We find that at least 10 voxels are needed to sufficiently resolve pore throats for single phase fluid flow simulations. If this condition is not met, additional analyses and corrections may allow for meaningful comparisons between simulation results and laboratory measurements of permeability, but some cases may fall outside the current technical feasibility of DRP. On the other hand, we find that the ratio of field of view and effective grain size provides a reliable measure of the REV for siliciclastic rocks. If this ratio is greater than 5, the coefficient of variation for single-phase permeability simulations drops below 15%. These imaging considerations are crucial when comparing digitally computed rock flow properties with those measured in the laboratory. We find that the current imaging methods are sufficient to achieve both REV (with respect to numerical boundary conditions) and required image resolution to perform digital core analysis for coarse to fine-grained sandstones.

  13. Scaled Hartree-Fock force field calculations for organothallium compounds: Normal-mode analysis for TlCH sub 3 Tl(CH sub 3 ) sub 2 sup + , Tl(CH sub 3 ) sub 3 , Tl(CH sub 3 ) sub 2 Br, and Tl(CH sub 3 ) sub 4 sup minus

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Schwerdtfeger, P.; Bowmaker, G.A.; Boyd, P.D.W.

    1990-02-01

    In a recent paper we presented Hartree-Fock (HF) calculations for aliphatic organothallium compounds. The diagonal HF force constants obtained from a Fletcher-Powell geometry optimization are now used for a normal-mode analysis of TlCH{sub 3}, Tl(CH{sub 3}){sub 2}{sup +}, Tl(CH{sub 3}){sub 3}, Tl(CH{sub 3}){sub 2}Br, and Tl(CH{sub 3}){sub 4}{sup {minus}}. In order to calculate frequencies comparable to experimental values, the HF force field has been scaled by using scaling factors obtained from experimental infrared and Raman measurements on Tl(CH{sub 3}){sub 2}{sup +} and TlBr. The vibrational spectra of Tl(CH{sub 3}){sub 2}{sup +} were remeasured (infrared and Raman) in order to obtainmore » an accurate force field. Predictions are made for the vibrational spectrum of the as yet undetected TlCH{sub 3} molecule. Experimental infrared and Raman results for Tl(CH{sub 3}){sub 3} compare reasonably well with our calculated frequencies. Relativistic and correlation effects are analyzed for the vibrational frequencies of Tl(CH{sub 3}){sub 2}{sup +}.« less

  14. ACOUSTICAL IMAGING AND MECHANICAL PROPERTIES OF SOFT ROCK AND MARINE SEDIMENTS

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Thurman E. Scott, Jr., Ph.D.; Younane Abousleiman, Ph.D.; Musharraf Zaman, Ph.D., P.E.

    2002-11-18

    During the sixth quarter of this research project the research team developed a method and the experimental procedures for acquiring the data needed for ultrasonic tomography of rock core samples under triaxial stress conditions as outlined in Task 10. Traditional triaxial compression experiments, where compressional and shear wave velocities are measured, provide little or no information about the internal spatial distribution of mechanical damage within the sample. The velocities measured between platen-to-platen or sensor-to-sensor reflects an averaging of all the velocities occurring along that particular raypath across the boundaries of the rock. The research team is attempting to develop andmore » refine a laboratory equivalent of seismic tomography for use on rock samples deformed under triaxial stress conditions. Seismic tomography, utilized for example in crosswell tomography, allows an imaging of the velocities within a discrete zone within the rock. Ultrasonic or acoustic tomography is essentially the extension of that field technology applied to rock samples deforming in the laboratory at high pressures. This report outlines the technical steps and procedures for developing this technology for use on weak, soft chalk samples. Laboratory tests indicate that the chalk samples exhibit major changes in compressional and shear wave velocities during compaction. Since chalk is the rock type responsible for the severe subsidence and compaction in the North Sea it was selected for the first efforts at tomographic imaging of soft rocks. Field evidence from the North Sea suggests that compaction, which has resulted in over 30 feet of subsidence to date, is heterogeneously distributed within the reservoir. The research team will attempt to image this very process in chalk samples. The initial tomographic studies (Scott et al., 1994a,b; 1998) were accomplished on well cemented, competent rocks such as Berea sandstone. The extension of the technology to weaker

  15. Types of rocks exposed at the Viking landing sites

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Guinness, E.; Arvidson, R.; Dale-Bannister, M.

    1985-01-01

    Spectral estimates derived from Viking Lander multispectral images have been used to investigate the types of rocks exposed at both landing sites, and to infer whether the rocks are primary igneous rocks or weathering products. These analyses should aid interpretations of spectra to be returned from the Visual and Infrared Mapping Spectrometer on the upcoming Mars Observer Mission. A series of gray surfaces on the Landers were used to check the accuracy of the camera preflight calibrations. Results indicate that the pre-flight calibrations for the three color channels are probably correct for all cameras but camera 2 on Lander 1.more » The calibration for the infrared channels appears to have changed, although the cause is not known. For this paper, only the color channels were used to derive data for rocks. Rocks at both sites exhibit a variety of reflectance values. For example, reflectance estimates for two rocks in the blue (0.4-0.5 microns), green (0.5-0.6 microns), and red (0.6-0.75 microns) channels are 0.16, 0.23, and 0.33 and 0.12, 0.19, 0.37 at a phase angle of 20 degrees. These values have been compared with laboratory reflectance spectra of analog materials and telescopic spectra of Mars, both convolved to the Lander bandpasses. Lander values for some rocks are similar to earth based observations of martian dark regions and with certain mafic igneous rocks thinly coated with amorphous ferric-oxide rich weathering products. These results are consistent with previous interpretations.« less

  16. Rock sample brought to earth from the Apollo 12 lunar landing mission

    NASA Technical Reports Server (NTRS)

    1969-01-01

    Close-up view of Apollo 12 sample 12,065 under observation in the Manned Spacecraft Center's Lunar Receiving Laboratory. This sample, collected during the second Apollo 12 extravehicular activity (EVA-2) of Astronauts Charles Conrad Jr., and Alan L. Bean, is a fine-grained rock. Note the glass-lined pits. An idea of the size of the rock can be gained by reference to the gauge on the bottom portion of the number meter.

  17. Weathering profiles in soils and rocks on Earth and Mars

    NASA Astrophysics Data System (ADS)

    Hausrath, E.; Adcock, C. T.; Bamisile, T.; Baumeister, J. L.; Gainey, S.; Ralston, S. J.; Steiner, M.; Tu, V.

    2017-12-01

    Interactions of liquid water with rock, soil, or sediments can result in significant chemical and mineralogical changes with depth. These changes can include transformation from one phase to another as well as translocation, addition, and loss of material. The resulting chemical and mineralogical depth profiles can record characteristics of the interacting liquid water such as pH, temperature, duration, and abundance. We use a combined field, laboratory, and modeling approach to interpret the environmental conditions preserved in soils and rocks. We study depth profiles in terrestrial field environments; perform dissolution experiments of primary and secondary phases important in soil environments; and perform numerical modeling to quantitatively interpret weathering environments. In our field studies we have measured time-integrated basaltic mineral dissolution rates, and interpreted the impact of pH and temperature on weathering in basaltic and serpentine-containing rocks and soils. These results help us interpret fundamental processes occurring in soils on Earth and on Mars, and can also be used to inform numerical modeling and laboratory experiments. Our laboratory experiments provide fundamental kinetic data to interpret processes occurring in soils. We have measured dissolution rates of Mars-relevant phosphate minerals, clay minerals, and amorphous phases, as well as dissolution rates under specific Mars-relevant conditions such as in concentrated brines. Finally, reactive transport modeling allows a quantitative interpretation of the kinetic, thermodynamic, and transport processes occurring in soil environments. Such modeling allows the testing of conditions under longer time frames and under different conditions than might be possible under either terrestrial field or laboratory conditions. We have used modeling to examine the weathering of basalt, olivine, carbonate, phosphate, and clay minerals, and placed constraints on the duration, pH, and solution

  18. Geophysical Properties of Hard Rock for Investigation of Stress Fields in Deep Mines

    NASA Astrophysics Data System (ADS)

    Tibbo, M.; Young, R. P.; Schmitt, D. R.; Milkereit, B.

    2014-12-01

    A complication in geophysical monitoring of deep mines is the high-stress dependency of the physical properties of hard rocks. In-mine observations show anisotropic variability of the in situ P- and S-wave velocities and resistivity of the hard rocks that are likely related to stress field changes. As part of a comprehensive study in a deep, highly stressed mine located in Sudbury, Ontario, Canada, data from in situ monitoring of the seismicity, conductivity, stress, and stress dependent physical properties has been obtain. In-laboratory experiments are also being performed on borehole cores from the Sudbury mines. These experiments will measure the Norite borehole core's properties including elastic modulus, bulk modulus, P- and S-wave velocities, and density. Hydraulic fracturing has been successfully implemented in industries such as oil and gas and enhanced geothermal systems, and is currently being investigated as a potential method for preconditioning in mining. However, further research is required to quantify how hydraulic fractures propagate through hard, unfractured rock as well as naturally fractured rock typically found in mines. These in laboratory experiments will contribute to a hydraulic fracturing project evaluating the feasibility and effectiveness of hydraulic fracturing as a method of de-stressing hard rock mines. A tri-axial deformation cell equipped with 18 Acoustic Emission (AE) sensors will be used to bring the borehole cores to a tri-axial state of stress. The cores will then be injected with fluid until the the hydraulic fracture has propagated to the edge of the core, while AE waveforms will be digitized continuously at 10 MHz and 12-bit resolution for the duration of each experiment. These laboratory hydraulic fracture experiments will contribute to understanding how parameters including stress ratio, fluid injection rate, and viscosity, affect the fracturing process.

  19. The Band of CH_3CH_2D from 770-880 wn

    NASA Astrophysics Data System (ADS)

    Daly, Adam M.; Drouin, Brian; Pearson, John; Groner, Peter; Sung, Keeyoon; Brown, Linda; Mantz, Arlan; Smith, Mary Ann H.

    2015-06-01

    To extend the ethane database we recorded a 0.0028 wn resolution spectrum of CH_3CH_2D from 650 to 1500 wn using a Bruker IFS-125HR at the Jet Propulsion Laboratory. The 98% deuterium-enriched sample was contained in the 0.2038 m absorption cell; one scan was taken with the sample cryogenically cooled to 130 K and another at room temperature. From the cold data, we retrieved line positions and intensities of 8704 individual absorption features from 770 - 880 wn using a least squares curve fitting algorithm. From this set of measurements, we assigned 5041 transitions to the νb{17} fundamental at 805.3427686(234) wn; this band is a c-type vibration, with A and E components arising from internal rotation. The positions were modeled using a 22 term torsional Hamiltonian using SPFIT producing the A and E energy splitting of 5.409(25)x10-3 wn (162.2(8) MHz) with a standard deviation of 7x10-4 wn (21 MHz). The calculated line intensities at 130 K agree very well with retrieved intensities. To predict line intensities at different temperatures, the partition function value was determined at eight temperatures between 9.8 and 300 K by summing individual energy levels up to J = 99 and Ka = 99 for the six states up through νb{17} at 805 wn. The resulting prediction of singly-deuterated ethane absorption at 12.5 μm enables its detection in planetary atmospheres, including those of Titan and exoplanets.

  20. Experimental Studies on Permeability of Intact and Singly Jointed Meta-Sedimentary Rocks Under Confining Pressure

    NASA Astrophysics Data System (ADS)

    Wong, Louis Ngai Yuen; Li, Diyuan; Liu, Gang

    2013-01-01

    spanning from 1.25 to 5.0 MPa, which represent the typical ground stress conditions in the cavern. The in situ hydraulic conductivity measurements conducted in six boreholes by the injection test showed that the in situ permeability of rock mass varies between 10-18 and 10-11 m2. The lower bound of the in situ permeability is larger than that of the present laboratory-tested intact rock specimens, while the upper bound of the in situ permeability is less than that of the present laboratory-tested jointed rock specimens. The in situ permeability test results were thus compatible with our present laboratory permeability results of both intact and jointed rock specimens.

  1. In Situ Observation of Hard Surrounding Rock Displacement at 2400-m-Deep Tunnels

    NASA Astrophysics Data System (ADS)

    Feng, Xia-Ting; Yao, Zhi-Bin; Li, Shao-Jun; Wu, Shi-Yong; Yang, Cheng-Xiang; Guo, Hao-Sen; Zhong, Shan

    2018-03-01

    This paper presents the results of in situ investigation of the internal displacement of hard surrounding rock masses within deep tunnels at China's Jinping Underground Laboratory Phase II. The displacement evolution of the surrounding rock during the entire excavation processes was monitored continuously using pre-installed continuous-recording multi-point extensometers. The evolution of excavation-damaged zones and fractures in rock masses were also observed using acoustic velocity testing and digital borehole cameras, respectively. The results show four kinds of displacement behaviours of the hard surrounding rock masses during the excavation process. The displacement in the inner region of the surrounding rock was found to be greater than that of the rock masses near the tunnel's side walls in some excavation stages. This leads to a multi-modal distribution characteristic of internal displacement for hard surrounding rock masses within deep tunnels. A further analysis of the evolution information on the damages and fractures inside the surrounding rock masses reveals the effects of excavation disturbances and local geological conditions. This recognition can be used as the reference for excavation and supporting design and stability evaluations of hard-rock tunnels under high-stress conditions.

  2. Formation of unexpected silicon- and disiloxane-bridged multiferrocenyl derivatives bearing Si-O-CH[double bond, length as m-dash]CH2 and Si-(CH2)2C(CH3)3 substituents via cleavage of tetrahydrofuran and trapping of its ring fragments.

    PubMed

    Bruña, Sonia; González-Vadillo, Ana Mª; Ferrández, Marta; Perles, Josefina; Montero-Campillo, M Merced; Mó, Otilia; Cuadrado, Isabel

    2017-09-12

    The formation of a family of silicon- and siloxane-bridged multiferrocenyl derivatives carrying different functional groups attached to silicon, including Fc 2 (CH 3 ) 3 C(CH 2 ) 2 SiCH[double bond, length as m-dash]CH 2 (5), Fc 2 (CH 2 [double bond, length as m-dash]CH-O)SiCH[double bond, length as m-dash]CH 2 (6), Fc 2 (OH)SiCH[double bond, length as m-dash]CH 2 (7), Fc 2 (CH 2 [double bond, length as m-dash]CH-O)Si-O-Si(O-CH[double bond, length as m-dash]CH 2 )Fc 2 (8) and Fc 2 (CH 2 [double bond, length as m-dash]CH-O)Si-O-SiFc 3 (9) is described. Silyl vinyl ether molecules 6, 8 and 9 and the heteroleptic vinylsilane 5 resulted from the competing metathesis reaction of lithioferrocene (FcLi), CH 2 [double bond, length as m-dash]CH-OLi or (CH 3 ) 3 C(CH 2 ) 2 Li with the corresponding multifunctional chlorosilane, Cl 3 SiCH[double bond, length as m-dash]CH 2 or Cl 3 Si-O-SiCl 3 . The last two organolithium species have been likely formed in situ by fragmentation of the tetrahydrofuran solvent. Diferrocenylvinyloxyvinylsilane 6 is noteworthy since it represents a rare example of a redox-active silyl mononomer in which two different C[double bond, length as m-dash]C polymerisable groups are directly connected to silicon. The molecular structures of the silicon-containing multiferrocenyl species 5, 6, 8 and 9 have been investigated by single-crystal X-ray diffraction studies, demonstrating the capture and storage processes of two ring fragments resulting from the cleavage of cyclic THF in redox-active and stable crystalline organometallic compounds. From electrochemical studies we found that by changing the anion of the supporting electrolyte from [PF 6 ] - to [B(C 6 F 5 ) 4 ] - , the redox behaviour of tetrametallic disiloxane 8 can be switched from a poorly resolved multistep redox process to four consecutive well-separated one-electron oxidations, corresponding to the sequential oxidation of the four ferrocenyl moieties.

  3. The potassic sedimentary rocks in Gale Crater, Mars, as seen by ChemCam on board Curiosity: Potassic Sedimentary Rocks, Gale Crater

    DOE PAGES

    Le Deit, L.; Mangold, N.; Forni, O.; ...

    2016-05-13

    The Mars Science Laboratory rover Curiosity encountered potassium-rich clastic sedimentary rocks at two sites in Gale Crater, the waypoints Cooperstown and Kimberley. These rocks include several distinct meters thick sedimentary outcrops ranging from fine sandstone to conglomerate, interpreted to record an ancient fluvial or fluvio-deltaic depositional system. Furthermore, from ChemCam Laser-Induced Breakdown Spectroscopy (LIBS) chemical analyses, this suite of sedimentary rocks has an overall mean K 2O abundance that is more than 5 times higher than that of the average Martian crust. The combined analysis of ChemCam data with stratigraphic and geographic locations then reveals that the mean K 2Omore » abundance increases upward through the stratigraphic section. Chemical analyses across each unit can be represented as mixtures of several distinct chemical components, i.e., mineral phases, including K-bearing minerals, mafic silicates, Fe-oxides, and Fe-hydroxide/oxyhydroxides. Possible K-bearing minerals include alkali feldspar (including anorthoclase and sanidine) and K-bearing phyllosilicate such as illite. Mixtures of different source rocks, including a potassium-rich rock located on the rim and walls of Gale Crater, are the likely origin of observed chemical variations within each unit. Physical sorting may have also played a role in the enrichment in K in the Kimberley formation. The occurrence of these potassic sedimentary rocks provides additional evidence for the chemical diversity of the crust exposed at Gale Crater.« less

  4. The potassic sedimentary rocks in Gale Crater, Mars, as seen by ChemCam on board Curiosity: Potassic Sedimentary Rocks, Gale Crater

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Le Deit, L.; Mangold, N.; Forni, O.

    The Mars Science Laboratory rover Curiosity encountered potassium-rich clastic sedimentary rocks at two sites in Gale Crater, the waypoints Cooperstown and Kimberley. These rocks include several distinct meters thick sedimentary outcrops ranging from fine sandstone to conglomerate, interpreted to record an ancient fluvial or fluvio-deltaic depositional system. Furthermore, from ChemCam Laser-Induced Breakdown Spectroscopy (LIBS) chemical analyses, this suite of sedimentary rocks has an overall mean K 2O abundance that is more than 5 times higher than that of the average Martian crust. The combined analysis of ChemCam data with stratigraphic and geographic locations then reveals that the mean K 2Omore » abundance increases upward through the stratigraphic section. Chemical analyses across each unit can be represented as mixtures of several distinct chemical components, i.e., mineral phases, including K-bearing minerals, mafic silicates, Fe-oxides, and Fe-hydroxide/oxyhydroxides. Possible K-bearing minerals include alkali feldspar (including anorthoclase and sanidine) and K-bearing phyllosilicate such as illite. Mixtures of different source rocks, including a potassium-rich rock located on the rim and walls of Gale Crater, are the likely origin of observed chemical variations within each unit. Physical sorting may have also played a role in the enrichment in K in the Kimberley formation. The occurrence of these potassic sedimentary rocks provides additional evidence for the chemical diversity of the crust exposed at Gale Crater.« less

  5. Mechanisms of Nutrient Acquisition by Rock Eating Microbes Revealed by Proteomics

    NASA Astrophysics Data System (ADS)

    Bryce, C. C.; Martin, S.; LeBihan, T.; Cockell, C.

    2013-12-01

    In nutrient poor terrestrial environments such as fresh lava flows, bioessential elements contained within surrounding rocks can be an important source of nutrients for the microbial community. The role of microbes in the alteration of rock surfaces, driven by this nutrient requirement, is widely accepted and is known to play an important role in CO2 drawdown as well as influencing nutrient flux to the biosphere. There is, however, limited knowledge of the biological processes which facilitate the uptake of bioessential elements from rocks. Using a technique known as 'shotgun' proteomics we have investigated the cellular processes involved in the uptake of iron, calcium and magnesium from fresh basalt in the heavy metal resistant bacterium Cupriavidus metallidurans CH34. Quantitative proteomics allows us to obtain a detailed snapshot of the protein complement of cells. By comparing cultures grown under normal growth conditions to cultures grown with basalt as an alternative iron, calcium or magnesium source, we can highlight proteins which are differentially expressed and therefore important for life in a rocky environment. We observe that the use of rock-bound nutrients induces a complex metabolic response in C.metallidurans which is distinct from the effects observed in the presence of rocks in normal growth medium. This is evidenced, for example, by the upregulation of a number of proteins involved in alternative energy-producing processes such as chemolithotrophy, sulphur oxidation and hydrogen oxidation compared to control cultures. This work has implications for the understanding of how microbes forge a life for themselves from the Earth's crust and highlights the importance of the field of proteomics for the study of life in terrestrial environments.

  6. Disproportionation and thermochemical sulfate reduction reactions in S-H20-Ch4 and S-D2O-CH4 systems from 200 to 340 °C at elevated pressures

    USGS Publications Warehouse

    Yuan, Shunda; Chou, I-Ming; Burruss, Robert A.

    2013-01-01

    Elemental sulfur, as a transient intermediate compound, by-product, or catalyst, plays significant roles in thermochemical sulfate reduction (TSR) reactions. However, the mechanisms of the reactions in S-H2O-hydrocarbons systems are not clear. To improve our understanding of reaction mechanisms, we conducted a series of experiments between 200 and 340 °C for S-H2O-CH4, S-D2O-CH4, and S-CH4-1m ZnBr2 systems in fused silica capillary capsules (FSCC). After a heating period ranging from 24 to 2160 hours (hrs), the quenched samples were analyzed by Raman spectroscopy. Combined with the in situ Raman spectra collected at high temperatures and pressures in the S-H2O and S-H2O-CH4 systems, our results showed that (1) the disproportionation of sulfur in the S-H2O-CH4 system occurred at temperatures above 200 °C and produced H2S, SO42-, and possibly trace amount of HSO4-; (2) sulfate (and bisulfate), in the presence of sulfur, can be reduced by methane between 250 and 340 °C to produce CO2 and H2S, and these TSR temperatures are much closer to those of the natural system (2O-CH4 system may take place simultaneously, with TSR being favored at higher temperatures; and (4) in the system S-D2O-CH4, both TSR and the competitive disproportionation reactions occurred simultaneously at temperatures above 300 °C, but these reactions were very slow at lower temperatures. Our observation of methane reaction at 250 °C in a laboratory time scale suggests that, in a geologic time scale, methane may be destroyed by TSR reactions at temperatures > 200 °C that can be reached by deep drilling for hydrocarbon resources.

  7. Mode I Fracture Toughness of Rock - Intrinsic Property or Pressure-Dependent?

    NASA Astrophysics Data System (ADS)

    Stoeckhert, F.; Brenne, S.; Molenda, M.; Alber, M.

    2016-12-01

    The mode I fracture toughness of rock is usually regarded as an intrinsic material parameter independent of pressure. However, most fracture toughness laboratory tests are conducted only at ambient pressure. To investigate fracture toughness of rock under elevated pressures, sleeve fracturing laboratory experiments were conducted with various rock types and a new numerical method was developed for the evaluation of these experiments. The sleeve fracturing experiments involve rock cores with central axial boreholes that are placed in a Hoek triaxial pressure cell to apply an isostatic confining pressure. A polymere tube is pressurized inside these hollow rock cylinders until they fail by tensile fracturing. Numerical simulations incorporating fracture mechanical models are used to obtain a relation between tensile fracture propagation and injection pressure. These simulations indicate that the magnitude of the injection pressure at specimen failure is only depending on the fracture toughness of the tested material, the specimen dimensions and the magnitude of external loading. The latter two are known parameters in the experiments. Thus, the fracture toughness can be calculated from the injection pressure recorded at specimen breakdown. All specimens had a borehole diameter to outer diameter ratio of about 1:10 with outer diameters of 40 and 62 mm. The length of the specimens was about two times the diameter. Maximum external loading was 7.5 MPa corresponding to maximum injection pressures at specimen breakdown of about 100 MPa. The sample set tested in this work includes Permian and Carboniferous sandstones, Jurassic limestones, Triassic marble, Permian volcanic rocks and Devonian slate from Central Europe. The fracture toughness values determined from the sleeve fracturing experiments without confinement using the new numerical method were found to be in good agreement with those from Chevron bend testing according to the ISRM suggested methods. At elevated

  8. Dual stable isotopes of CH4 from Yellowstone hot-springs suggest hydrothermal processes involving magmatic CO2

    NASA Astrophysics Data System (ADS)

    Moran, James J.; Whitmore, Laura M.; Jay, Zackary J.; Jennings, Ryan deM.; Beam, Jacob P.; Kreuzer, Helen W.; Inskeep, William P.

    2017-07-01

    Volcanism and post-magmatism contribute significant annual methane (CH4) fluxes to the atmosphere (on par with other natural sources such as forest fire and wild animal emissions) and have been implicated in past climate-change events. The Yellowstone hot spot is one of the largest volcanic systems on Earth and is known to emit CH4 (as well as carbon dioxide (CO2) and other gases), but the ultimate sources of this CH4 flux have not been elucidated. Here we use dual stable isotope analysis (δ2H and δ13C) of CH4 sampled from ten high-temperature geothermal pools in Yellowstone National Park along with other isotopic and gas analyses to evaluate potential sources of methane. The average δ13C and δ2H values of CH4 emitted from hot springs (26.7 (± 2.4) and - 236.9 (± 12.0) ‰, respectively) are inconsistent with microbial methanogenesis but do not allow distinction between thermogenic and abiotic sources. Correlation between δ13CCH4 and δ13C of dissolved inorganic C (DIC) is consistent with DIC as the parent C source for the observed CH4, or with equilibration of CH4 and DIC. Methane formation temperatures estimated by isotopic geothermometry based on δ13CCH4 and δ13CCO2 ranged from 250-350 °C, which is just below previous temperature estimates for the hydrothermal reservoir. Further, the δ2HH2O of the thermal springs and the measured δ2HCH4 values are consistent with equilibration between the source water and the CH4 at the formation temperatures. Though the ultimate origin of the CH4 could be attributed to either abiotic of themorgenic processes with subsequent isotopic equilibration, the C1/C2 + composition of the gases is more consistent with abiotic origins for most of the samples. Thus, our data support the hypothesis that subsurface rock-water interactions are responsible for at least a significant fraction of the CH4 flux from the Yellowstone National Park volcanic system.

  9. Paleomagnetism and alteration of lower Paleozoic rocks and Precambrian basement in the SHADS No. 4 drill core, Oklahoma

    NASA Astrophysics Data System (ADS)

    Evans, S. C.; Hamilton, M.; Hardwick, J.; Terrell, C.; Elmore, R. D.

    2017-12-01

    The chacterization of the lower Paleozoic sedimentary rock and the underlying Precambrian basement in northern Oklahoma is currently the subject of research to better understand induced seismicity in Oklahoma. We are investigating approximately 140 meters of igneous basement and over 300 meters of Ordovician Arbuckle Group carbonates and underlying sandstone in the Amoco SHADS No. 4 drill core from Rogers Co., Oklahoma, to better understand the nature, origin, and timing of fluid alteration and the relationship between fluid flow in the Arbuckle Group and the basement. Preliminary attempts to orient the core using the viscous remanent magnetization (VRM) method were unsuccessful, probably due to a steep drilling-induced component. The dolomitized Arbuckle Group contains a characteristic remanent magnetization (ChRM) with shallow inclinations (-5°) and variable declinations that, based on unblocking temperatures, is interpreted to reside in magnetite. This ChRM is interpreted as a chemical remanent magnetization (CRM) acquired in the Permian based on the shallow inclinations. The CRM could be related to hydrothermal fluids which migrated into the rocks in the late Paleozoic, as other studies in northern Oklahoma have reported. The Arbuckle Group dolomites are porous and extensively altered and consist of several generations of dolomite, including baroque dolomite. The basement rock is andesitic to trachytic ignimbrite that exhibits extensive alteration. There are many near-vertical fractures mineralized with epidote that are cross cut by calcite-filled fractures. Anisotropy of magnetic susceptibility (AMS) measurements indicate an oblate fabric in the top of the basement and the overlying sandstones. At greater depths, the AMS is variable and may include both alteration and primary fabrics. Demagnetization of the basement rocks is in the initial stages. We are currently investigating if and how far the alteration in the Arbuckle Group extended into the basement

  10. Effects of Contaminated Fluids on Complex Moduli in Porous Rocks; Lab and Field.

    NASA Astrophysics Data System (ADS)

    Spetzler, H.; Snieder, R.; Zhang, J.

    2006-12-01

    The interaction between fluids and porous rocks has been measured in the laboratory and in a controlled field experiment. In the laboratory we measured the static and dynamic effect of various contaminated fluids on the wettability, capillary pressure and other flow properties on geometrically simple surfaces. The characteristics of the menisci were quantified by measuring the forces required to deform and move them. Rate dependent surface tension and contact angles describe the hysteresis of the contact line motion. Finally we used geometrically complex surfaces, i.e. real rocks, and observed similar behavior. Then we did a field experiment where we could controllably irrigate a test volume and observe changes in deformation. At low deformation rates, where viscous deformation of the fluid is negligible, the dynamic hystereses of menisci deformation become the dominant mechanism for changes in complex moduli of partially fluid saturated rocks. In the laboratory for contaminated samples we observe attenuation increasing from below 1 Hz to 1 mHz, the limit of our patience in making these measurements. In the field we used microseisms and solid Earth tides as low frequency deformation sources. In the case of the tides we compare changes in observed tilt with theoretical site specific tidal tilts. Preliminary theoretical modeling suggests that indeed small changes in the moduli should be observable in changes in tilt response. In this paper we present our laboratory results and the field data and analysis to date.

  11. Some Data from Detection of Organics in a Rock on Mars

    NASA Image and Video Library

    2014-12-16

    Data graphed here are examples from the Sample Analysis at Mars SAM laboratory detection of Martian organics in a sample of powder that the drill on NASA Curiosity Mars rover collected from a rock target called Cumberland.

  12. Prevention of sulfide oxidation in sulfide-rich waste rock

    NASA Astrophysics Data System (ADS)

    Nyström, Elsa; Alakangas, Lena

    2015-04-01

    The ability to reduce sulfide oxidation in waste rock after mine closure is a widely researched area, but to reduce and/or inhibit the oxidation during operation is less common. Sulfide-rich (ca 30 % sulfur) waste rock, partially oxidized, was leached during unsaturated laboratory condition. Trace elements such as As and Sb were relatively high in the waste rock while other sulfide-associated elements such as Cu, Pb and Zn were low compared to common sulfide-rich waste rock. Leaching of unsaturated waste rock lowered the pH, from around six down to two, resulting in continuously increasing element concentrations during the leaching period of 272 days. The concentrations of As (65 mg/L), Cu (6.9 mg/L), Sb (1.2 mg/L), Zn (149 mg/L) and S (43 g/L) were strongly elevated at the end of the leaching period. Different alkaline industrial residues such as slag, lime kiln dust and cement kiln dust were added as solid or as liquid to the waste rock in an attempt to inhibit sulfide oxidation through neo-formed phases on sulfide surfaces in order to decrease the mobility of metals and metalloids over longer time scale. This will result in a lower cost and efforts of measures after mine closure. Results from the experiments will be presented.

  13. Mars Science Laboratory: Results From Bradbury Landing to Glenelg

    NASA Astrophysics Data System (ADS)

    Grotzinger, John; Blake, Dave; Crisp, Joy; Edgett, Ken; Gellert, Ralf; Gomez Elvira, Javier; Hassler, Don; Mahaffy, Paul; Malin, Mike; Mitrofanov, Igor; Meyer, Michael; Vasavada, Ashwin; Wiens, Roger; MSL Science Team

    2013-04-01

    The Mars Science Laboratory rover, Curiosity, analyzed rocks, soils, and the atmosphere between Bradbury Landing and the contact with a light-toned, fractured , high-thermal inertia unit ~500 meters to the east ("Glenelg"). A number of in-place outcrops were encountered along this traverse that allows a simple stratigraphy to be con-structed. A variety of siliciclastic sedimentary rocks are present in the section, possibly also including minor basaltic volcanics. At several localities en route to Glenelg, Curiosity observed conglomeratic bedrock containing rounded pebbles ranging in size from 5-40 mm, forming beds at least 5 cm thick with locally well-developed planar stratification; this, plus grain-supported and imbricated clast fabrics suggest transport in aqueous flows with depths of 0.1-0.8 m, and velocities of 14-63 cm/sec. These conglomerates were likely derived from the Gale crater rim and transported down the Peace Vallis channel network; ChemCam data suggest the presence of feldspar and basaltic composition rock fragments as pebbles. APXS and ChemCam data show the out-of-place rock, "Jake Matijevic", to have an evolved, alkaline composi-tion similar to nepheline-normative muegerites, and suggestive of high pressure partial melting of the mantle. Other, stratigraphically in-place rocks show basanitic composition, with high K2O, low SiO2, and high FeO. Between Sols 56 and 110 Curiosity studied the "Rocknest" eolian deposit which was selected for scooping and eventual delivery to CheMin and SAM. The APXS composition of this deposit is consistent with average Mars soils encountered by previous missions (SO3 + Cl ~6 wt.%). Scooped samples delivered to CheMin reveal the presence of forsterite, pigeonite, augite, plagioclase, and several trace minerals including quartz, anhydrite, magnetite, hematite and illmenite. SAM analysis of the scooped soil yielded four different Evolved Gas Analysis (EGA) experiments depending on the temperature at which evolved gases

  14. Geomechanical rock properties of a basaltic volcano

    NASA Astrophysics Data System (ADS)

    Schaefer, Lauren; Kendrick, Jackie; Lavallée, Yan; Oommen, Thomas; Chigna, Gustavo

    2015-06-01

    In volcanic regions, reliable estimates of mechanical properties for specific volcanic events such as cyclic inflation-deflation cycles by magmatic intrusions, thermal stressing, and high temperatures are crucial for building accurate models of volcanic phenomena. This study focuses on the challenge of characterizing volcanic materials for the numerical analyses of such events. To do this, we evaluated the physical (porosity, permeability) and mechanical (strength) properties of basaltic rocks at Pacaya Volcano (Guatemala) through a variety of laboratory experiments, including: room temperature, high temperature (935 °C), and cyclically-loaded uniaxial compressive strength tests on as-collected and thermally-treated rock samples. Knowledge of the material response to such varied stressing conditions is necessary to analyze potential hazards at Pacaya, whose persistent activity has led to 13 evacuations of towns near the volcano since 1987. The rocks show a non-linear relationship between permeability and porosity, which relates to the importance of the crack network connecting the vesicles in these rocks. Here we show that strength not only decreases with porosity and permeability, but also with prolonged stressing (i.e., at lower strain rates) and upon cooling. Complimentary tests in which cyclic episodes of thermal or load stressing showed no systematic weakening of the material on the scale of our experiments. Most importantly, we show the extremely heterogeneous nature of volcanic edifices that arise from differences in porosity and permeability of the local lithologies, the limited lateral extent of lava flows, and the scars of previous collapse events. Input of these process-specific rock behaviors into slope stability and deformation models can change the resultant hazard analysis. We anticipate that an increased parameterization of rock properties will improve mitigation power.

  15. Gage for measuring displacements in rock samples

    DOEpatents

    Holcomb, D.J.; McNamee, M.J.

    1985-07-18

    A gage for measuring diametral displacement within a rock sample for use in a rock mechanics laboratory and in the field, comprises a support ring housing a linear variable differential transformer (LVDT), a mounting screw, and a leaf spring. The mounting screw is adjustable and defines a first point of contact with the rock sample. The leaf spring has opposite ends fixed to the inner periphery of the mounting ring. An intermediate portion of the leaf spring projecting radially inward from the ring is formed with a dimple defining a second point of contact with the sample. The first and second points of contact are diametrically opposed to each other. The LVDT is mounted in the ring with its axis parallel to the line of measurement and its core rod received in the dimple of the leaf spring. Any change in the length of the line between the first and second support points is directly communicated to the LVDT. The leaf spring is rigid to completely support lateral forces so that the LVDT is free of all load for improved precision.

  16. Gage for measuring displacements in rock samples

    DOEpatents

    Holcomb, David J.; McNamee, Michael J.

    1986-01-01

    A gage for measuring diametral displacement within a rock sample for use in a rock mechanics laboratory and in the field, comprises a support ring housing a linear variable differential transformer, a mounting screw, and a leaf spring. The mounting screw is adjustable and defines a first point of contact with the rock sample. The leaf spring has opposite ends fixed to the inner periphery of the mounting ring. An intermediate portion of the leaf spring projecting radially inward from the ring is formed with a dimple defining a second point of contact with the sample. The first and second points of contact are diametrically opposed to each other. The LVDT is mounted in the ring with its axis parallel to the line of measurement and its core rod received in the dimple of the leaf spring. Any change in the length of the line between the first and second support points is directly communicated to the LVDT. The leaf spring is rigid to completely support lateral forces so that the LVDT is free of all load for improved precision.

  17. Evolution of strength and physical properties of carbonate and ultramafic rocks under hydrothermal conditions

    NASA Astrophysics Data System (ADS)

    Lisabeth, Harrison Paul

    Interaction of rocks with fluids can significantly change mineral assemblage and structure. This so-called hydrothermal alteration is ubiquitous in the Earth's crust. Though the behavior of hydrothermally altered rocks can have planet-scale consequences, such as facilitating oceanic spreading along slow ridge segments and recycling volatiles into the mantle at subduction zones, the mechanisms involved in the hydrothermal alteration are often microscopic. Fluid-rock interactions take place where the fluid and rock meet. Fluid distribution, flux rate and reactive surface area control the efficiency and extent of hydrothermal alteration. Fluid-rock interactions, such as dissolution, precipitation and fluid mediated fracture and frictional sliding lead to changes in porosity and pore structure that feed back into the hydraulic and mechanical behavior of the bulk rock. Examining the nature of this highly coupled system involves coordinating observations of the mineralogy and structure of naturally altered rocks and laboratory investigation of the fine scale mechanisms of transformation under controlled conditions. In this study, I focus on fluid-rock interactions involving two common lithologies, carbonates and ultramafics, in order to elucidate the coupling between mechanical, hydraulic and chemical processes in these rocks. I perform constant strain-rate triaxial deformation and constant-stress creep tests on several suites of samples while monitoring the evolution of sample strain, permeability and physical properties. Subsequent microstructures are analyzed using optical and scanning electron microscopy. This work yields laboratory-based constraints on the extent and mechanisms of water weakening in carbonates and carbonation reactions in ultramafic rocks. I find that inundation with pore fluid thereby reducing permeability. This effect is sensitive to pore fluid saturation with respect to calcium carbonate. Fluid inundation weakens dunites as well. The addition of

  18. Direct observation of unimolecular decay of CH 3 CH 2 CHOO Criegee intermediates to OH radical products

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Fang, Yi; Liu, Fang; Klippenstein, Stephen J.

    2016-07-28

    The unimolecular decay of carbonyl oxide intermediates, known as Criegee intermediates, produced in alkene ozonolysis is a significant source of OH radicals in the troposphere. Here, the rate of appearance of OH radical products is examined directly in the time-domain for a prototypical alkyl-substituted Criegee intermediate, CH3CH2CHOO, following vibrational activation under collision-free conditions. Complementary statistical Rice-Ramsperger-Kassel-Marcus calculations of the microcanonical unimolecular decay rate for CH3CH2CHOO are also carried out at energies in the vicinity of the barrier for 1,4 hydrogen atom transfer that leads to OH products. Tunneling through the barrier, derived from high level electronic structure calculations, contributes significantlymore » to the decay rate. Infrared transitions of CH3CH2CHOO are identified in the CH stretch overtone region, which are detected by ultraviolet laser-induced fluorescence of the resultant OH products. The features observed are attributed to CH vibrational excitations and conformational forms utilizing insights from theory. Both experiment and theory yield unimolecular decay rates for CH3CH2CHOO of ca. 10(7) s(-1), which are slower than those obtained for syn-CH3CHOO or (CH3)(2)COO reported previously [Fang et al., J. Chem. Phys. 144, 061102 (2016)] at similar energies. Master equation modeling is also utilized to predict the thermal decay rate of CH3CH2CHOO under atmospheric conditions, giving a rate of 279 s(-1) at 298 K.« less

  19. 3D Printing and Digital Rock Physics for the Geosciences

    NASA Astrophysics Data System (ADS)

    Martinez, M. J.; Yoon, H.; Dewers, T. A.

    2014-12-01

    Imaging techniques for the analysis of porous structures have revolutionized our ability to quantitatively characterize geomaterials. For example, digital representations of rock from CT images and physics modeling based on these pore structures provide the opportunity to further advance our quantitative understanding of fluid flow, geomechanics, and geochemistry, and the emergence of coupled behaviors. Additive manufacturing, commonly known as 3D printing, has revolutionized production of custom parts, to the point where parts might be cheaper to print than to make by traditional means in a plant and ship. Some key benefits of additive manufacturing include short lead times, complex shapes, parts on demand, zero required inventory and less material waste. Even subtractive processing, such as milling and etching, may be economized by additive manufacturing. For the geosciences, recent advances in 3D printing technology may be co-opted to print reproducible porous structures derived from CT-imaging of actual rocks for experimental testing. The use of 3D printed microstructure allows us to surmount typical problems associated with sample-to-sample heterogeneity that plague rock physics testing and to test material response independent from pore-structure variability. Together, imaging, digital rocks and 3D printing potentially enables a new workflow for understanding coupled geophysical processes in a real, but well-defined setting circumventing typical issues associated with reproducibility, enabling full characterization and thus connection of physical phenomena to structure. In this talk we will discuss the possibilities that the marriage of these technologies can bring to geosciences, including examples from our current research initiatives in developing constitutive laws for transport and geomechanics via digital rock physics. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of

  20. Influence of Water Content on Mechanical Properties of Rock in Both Saturation and Drying Processes

    NASA Astrophysics Data System (ADS)

    Zhou, Zilong; Cai, Xin; Cao, Wenzhuo; Li, Xibing; Xiong, Cheng

    2016-08-01

    Water content has a pronounced influence on the properties of rock materials, which is responsible for many rock engineering hazards, such as landslides and karst collapse. Meanwhile, water injection is also used for the prevention of some engineering disasters like rock-bursts. To comprehensively investigate the effect of water content on mechanical properties of rocks, laboratory tests were carried out on sandstone specimens with different water contents in both saturation and drying processes. The Nuclear Magnetic Resonance technique was applied to study the water distribution in specimens with variation of water contents. The servo-controlled rock mechanics testing machine and Split Hopkinson Pressure Bar technique were used to conduct both compressive and tensile tests on sandstone specimens with different water contents. From the laboratory tests, reductions of the compressive and tensile strength of sandstone under static and dynamic states in different saturation processes were observed. In the drying process, all of the saturated specimens could basically regain their mechanical properties and recover its strength as in the dry state. However, for partially saturated specimens in the saturation and drying processes, the tensile strength of specimens with the same water content was different, which could be related to different water distributions in specimens.

  1. Proceedings of the International Symposium on Dynamics of Fluids in Fractured Rocks: Concepts and Recent Advances

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Faybishenko, B.

    1999-02-01

    This publication contains extended abstracts of papers presented at the International Symposium ''Dynamics of Fluids in Fractured Rocks: Concepts and Recent Advances'' held at Ernest Orlando Lawrence Berkeley National Laboratory on February 10-12, 1999. This Symposium is organized in Honor of the 80th Birthday of Paul A. Witherspoon, who initiated some of the early investigations on flow and transport in fractured rocks at the University of California, Berkeley, and at Lawrence Berkeley National Laboratory. He is a key figure in the development of basic concepts, modeling, and field measurements of fluid flow and contaminant transport in fractured rock systems. Themore » technical problems of assessing fluid flow, radionuclide transport, site characterization, modeling, and performance assessment in fractured rocks remain the most challenging aspects of subsurface flow and transport investigations. An understanding of these important aspects of hydrogeology is needed to assess disposal of nu clear wastes, development of geothermal resources, production of oil and gas resources, and remediation of contaminated sites. These Proceedings of more than 100 papers from 12 countries discuss recent scientific and practical developments and the status of our understanding of fluid flow and radionuclide transport in fractured rocks. The main topics of the papers are: Theoretical studies of fluid flow in fractured rocks; Multi-phase flow and reactive chemical transport in fractured rocks; Fracture/matrix interactions; Hydrogeological and transport testing; Fracture flow models; Vadose zone studies; Isotopic studies of flow in fractured systems; Fractures in geothermal systems; Remediation and colloid transport in fractured systems; and Nuclear waste disposal in fractured rocks.« less

  2. Nuclear Hyperfine Structure in the Donor – Acceptor Complexes (CH3)3N-BF3 and (CH)33N-B(CH3)3

    EPA Science Inventory

    The donor-acceptor complexes (CH3)3N-BF3 and (CH3)3N-B(CH3)3 have been reinvestigated at high resolution by rotational spectroscopy in a supersonic jet. Nuclear hyperfine structure resulting from both nitrogen and boron has been resolved and quadrupole coupling constants have bee...

  3. Line Parameters Of CH3CN From 305 To 415 cm-1

    NASA Astrophysics Data System (ADS)

    Brown, Linda R.; Kamadjeu, D. A.; Kleiner, I.; Orphal, J.; Sams, R. L.

    2006-12-01

    Mapping important compounds, such as hydrocarbons and nitriles, is needed in order to understand the photochemical cycle of Titan and how it couples with the dynamics to produce organic aerosols. For this, the CIRS spectrometer (Composite Infrared Spectrometer) on board Cassini is currently recording rotation and vibration-rotation spectra of Titan between 10 and 1400 cm-1. To support analysis of these data, high resolution laboratory spectra of CH3CN have been recorded using Fourier transform spectrometers at PNL and LISA. This paper presents a prediction of line positions and intensities of CH3 CN for the ν&8 fundamental and the 2ν8 -ν8 hot band (located near 360 cm&-1). Analyses of the two fundamentals near 10 microns are in progress. Part of the research described in this paper was performed at the Jet Propulsion Laboratory, California Institute of Technology, under contract with The National Aeronautics and Space Administration. I.K, J. O and A. D. also want to thank the Programme National de Planétologie for funding part of this research. This research was supported, in part, by the United States Department of Energy, Office of Basic Energy Sciences, Chemical Sciences Division and the experimental part was performed at the W. R, Wiley Environmental Molecular Science Laboratory, a national scientific user facility sponsored by the Department of Energy's Office of Biological and Environmental Research located at the Pacific Northwest National Laboratory. Pacific Northwest National Laboratory is operated for the United States Department of Energy by Battelle under contract DE-AC06-76RLO 1830. We wish to thank Drs R. Antilla and S. Alanko for kindly making available supplemental data in electronic and paper forms. #

  4. The Possible Interstellar Anion CH2CN-: Spectroscopic Constants, Vibrational Frequencies, and Other Considerations

    NASA Astrophysics Data System (ADS)

    Fortenberry, Ryan C.; Crawford, T. Daniel; Lee, Timothy J.

    2013-01-01

    The A\\ ^1B_1 \\leftarrow \\tilde{X}\\ ^1A^{\\prime } excitation into the dipole-bound state of the cyanomethyl anion (CH2CN-) has been hypothesized as the carrier for one diffuse interstellar band. However, this particular molecular system has not been detected in the interstellar medium even though the related cyanomethyl radical and the isoelectronic ketenimine molecule have been found. In this study, we are employing the use of proven quartic force fields and second-order vibrational perturbation theory to compute accurate spectroscopic constants and fundamental vibrational frequencies for \\tilde{X}\\ ^1A^{\\prime } CH2CN- in order to assist in laboratory studies and astronomical observations.

  5. Correlation of the Rock Mass Rating (RMR) System with the Unified Soil Classification System (USCS): Introduction of the Weak Rock Mass Rating System (W-RMR)

    NASA Astrophysics Data System (ADS)

    Warren, Sean N.; Kallu, Raj R.; Barnard, Chase K.

    2016-11-01

    Underground gold mines in Nevada are exploiting increasingly deeper ore bodies comprised of weak to very weak rock masses. The Rock Mass Rating (RMR) classification system is widely used at underground gold mines in Nevada and is applicable in fair to good-quality rock masses, but is difficult to apply and loses reliability in very weak rock mass to soil-like material. Because very weak rock masses are transition materials that border engineering rock mass and soil classification systems, soil classification may sometimes be easier and more appropriate to provide insight into material behavior and properties. The Unified Soil Classification System (USCS) is the most likely choice for the classification of very weak rock mass to soil-like material because of its accepted use in tunnel engineering projects and its ability to predict soil-like material behavior underground. A correlation between the RMR and USCS systems was developed by comparing underground geotechnical RMR mapping to laboratory testing of bulk samples from the same locations, thereby assigning a numeric RMR value to the USCS classification that can be used in spreadsheet calculations and geostatistical analyses. The geotechnical classification system presented in this paper including a USCS-RMR correlation, RMR rating equations, and the Geo-Pick Strike Index is collectively introduced as the Weak Rock Mass Rating System (W-RMR). It is the authors' hope that this system will aid in the classification of weak rock masses and more usable design tools based on the RMR system. More broadly, the RMR-USCS correlation and the W-RMR system help define the transition between engineering soil and rock mass classification systems and may provide insight for geotechnical design in very weak rock masses.

  6. Rethinking how Undergraduate ``Hard Rock'' Petrology is Taught

    NASA Astrophysics Data System (ADS)

    Reid, M. R.

    2010-12-01

    A course in "hard rock" petrology forms a core component of undergraduate training in the geosciences. In most cases, the subjects of igneous and metamorphic petrology are combined in a single course and the course is traditionally structured so that the two subjects are covered in series. This approach enables students to focus on each subject separately, with knowledge of igneous rocks helping students to understand metamorphic rock protoliths. Student assessment shows, however, that this approach tends to compartmentalize learning and the two main subjects might just as well be taught in separate courses. In practical applications such as fieldwork, students must be able to access their understanding of igneous and metamorphic rocks virtually simultaneously. To better integrate student learning, I developed a spiral learning approach to teaching petrology (e.g., Bruner, 1990; Dyar et al., 2004) so that commonalities could be revisited several times over the course of a semester and, in so doing, students' grasp of the fundamental insights provided by igneous and metamorphic rocks could be scaffolded into greater understanding. The course initially focuses on the dynamics of the environments in which igneous and metamorphic rocks form: heat flow, fluid flow, and plate tectonics. Several subsequent weeks explore topics relevant to identifying and understanding igneous and metamorphic rocks in the field: crystal nucleation and growth, the roles of pressure and heat, and field classification. Laboratory exercises parallel this structure, also emphasizing observations that are valuable in the field: the relationship between minerals and rocks, textural observations, and general rock classification. The final portion of the course explores “hard rocks” in more detail with a greater emphasis on the interplay between chemistry and mineralogy. A variety of learner-centered activities in the course help students bridge the gap between novice and expert and include

  7. Rocks.

    ERIC Educational Resources Information Center

    Lee, Alice

    This science unit is designed for limited- and non-English speaking students in a Chinese bilingual education program. The unit covers rock material, classification, characteristics of types of rocks, and rock cycles. It is written in Chinese and simple English. At the end of the unit there is a list of main terms in both English and Chinese, and…

  8. Temperature Dependence of the Rate Constant for the CH3 Recombination Reaction: A Loss Process in Outer Planet Atmospheres

    NASA Technical Reports Server (NTRS)

    Cody, R. J.; Payne, W. A.; Thorn, R. P., Jr.; Romani, P. N.; Stief, L. J.; Nesbitt, F. L.; Iannone, M. A.; Tardy, D. C.

    2002-01-01

    The methyl free radical (CH3) has been observed in the atmospheres of Saturn and Neptune by the ISO satellite. There are discrepancies between the column densities for the CH3 radical derived from the ISO observations and the column densities derived from atmospheric photochemical models. For Neptune the model column density is 1.5 times that derived from ISO. For Saturn the model is 6 times that from ISO. The recombination of methyl radicals is the major loss process for methyl in these atmospheres. The serious disagreement between observed and calculated levels of CH3 has led to suggestions that the atmospheric models greatly underestimated the loss of CH3 due to poor knowledge of the rate of the reaction (1) CH3 + CH3 + M goes to C2H6 + M at the low temperatures and pressures of these atmospheric systems. Although the reaction CH3 + CH3 + M goes to C2H6 + M has been extensively studied both theoretically and experimentally, the laboratory conditions have been, with only a few exceptions, higher temperatures (T greater than 298K), higher pressures (P greater than or equal to 10 Torr - 13.3 mbar) or M=Ar rather than H2 or He as the bath gas.

  9. Laboratory Needs for Interstellar Ice Studies

    NASA Astrophysics Data System (ADS)

    Boogert, Abraham C. A.

    2012-05-01

    A large fraction of the molecules in dense interstellar and circumstellar environments is stored in icy grain mantles. The mantles are formed by a complex interplay between chemical and physical processes. Key questions on the accretion and desorption processes and the chemistry on the grain surfaces and within the icy mantles can only be answered by laboratory experiments. Recent infrared (2-30 micron) spectroscopic surveys of large samples of Young Stellar Objects (YSOs) and background stars tracing quiescent cloud material have shown that the ice band profiles and depths vary considerably as a function of environment. Using laboratory spectra in the identification process, it is clear that a rather complex mixture of simple species (CH3OH, CO2, H2O, CO) exists even in the quiescent cloud phase. Variations of the local physical conditions (CO freeze out) and time scales (CH3OH formation) appear to be key factors in the observed variations. Sublimation and thermal processing dominate as YSOs heat their environments. The identification of several ice absorption features is still disputed. I will outline laboratory work (e.g., on salts, PAHs, and aliphatic hydrocarbons) needed to further constrain the ice band identification as well as the thermal and chemical history of the carriers. Such experiments will also be essential to interpret future high spectral resolution SOFIA and JWST observations.

  10. Laboratory Particle Velocity Experiments on (JVE) Analog Rock

    DTIC Science & Technology

    1990-10-01

    1620 Dr. Richard LaCoss Prof. William Menke MIT-Lincoln Laboratory Lamont-Doherty Geological Observatory M-200B of Columbia University P. 0. Box 73...Building #77 University Park University of Arizona Los Angeles, CA 90089-0741 Tucson, AZ 85721 Prof. Christopher H. Scholz Dr. William Wortman Lamont...Stt"d University 11800 Sunrise Valley Drive, Suite 1212 Stanfora, CA 94305 Reston, VA 22091 Mr William J. Best Prof. Robert W. Clayton 907 Westwood

  11. ChIP-chip versus ChIP-seq: Lessons for experimental design and data analysis

    PubMed Central

    2011-01-01

    Background Chromatin immunoprecipitation (ChIP) followed by microarray hybridization (ChIP-chip) or high-throughput sequencing (ChIP-seq) allows genome-wide discovery of protein-DNA interactions such as transcription factor bindings and histone modifications. Previous reports only compared a small number of profiles, and little has been done to compare histone modification profiles generated by the two technologies or to assess the impact of input DNA libraries in ChIP-seq analysis. Here, we performed a systematic analysis of a modENCODE dataset consisting of 31 pairs of ChIP-chip/ChIP-seq profiles of the coactivator CBP, RNA polymerase II (RNA PolII), and six histone modifications across four developmental stages of Drosophila melanogaster. Results Both technologies produce highly reproducible profiles within each platform, ChIP-seq generally produces profiles with a better signal-to-noise ratio, and allows detection of more peaks and narrower peaks. The set of peaks identified by the two technologies can be significantly different, but the extent to which they differ varies depending on the factor and the analysis algorithm. Importantly, we found that there is a significant variation among multiple sequencing profiles of input DNA libraries and that this variation most likely arises from both differences in experimental condition and sequencing depth. We further show that using an inappropriate input DNA profile can impact the average signal profiles around genomic features and peak calling results, highlighting the importance of having high quality input DNA data for normalization in ChIP-seq analysis. Conclusions Our findings highlight the biases present in each of the platforms, show the variability that can arise from both technology and analysis methods, and emphasize the importance of obtaining high quality and deeply sequenced input DNA libraries for ChIP-seq analysis. PMID:21356108

  12. Spectroscopic line parameters of 12CH4 for atmospheric composition retrievals in the 4300-4500 cm-1 region

    NASA Astrophysics Data System (ADS)

    Hashemi, R.; Predoi-Cross, A.; Nikitin, A. V.; Tyuterev, Vl. G.; Sung, K.; Smith, M. A. H.; Malathy Devi, V.

    2017-01-01

    Due to the importance of methane as a trace atmospheric gas and a greenhouse gas, we have carried out a precise line-shape study to obtain the CH4-CH4 and CH4-air half-width coefficients, CH4-CH4 and CH4-air shift coefficients and off-diagonal relaxation matrix element coefficients for methane transitions in the spectral range known as the "methane Octad". In addition, the associated temperature dependences of these coefficients have been measured in the 4300-4500 cm-1 region of the Octad. The high signal to noise ratio spectra of pure methane and of dilute mixtures of methane in dry air with high resolution have been recorded at temperatures from 148 K to room temperature using the Bruker IFS 125 HR Fourier transform spectrometer (FTS) at the Jet Propulsion Laboratory, Pasadena, California. The analysis of spectra was done using a multispectrum non-linear least-squares curve fitting technique. Theoretical calculations have been performed and the results are compared with the previously published line positions, intensities and with the line parameters available in the GEISA and HITRAN2012 databases.

  13. Seasonal variation in CH4 emissions and production and oxidation potentials at microsites on an oligotrophic pine fen.

    PubMed

    Saarnio, S; Alm, Jukka; Silvola, Jouko; Lohila, Annalea; Nykänen, Hannu; Martikainen, Pertti J

    1997-04-01

     Temporal and spatial variation in CH 4 emissions was studied at hummock, Eriophorum lawn, flark and Carex lawn microsites in an oligotrophic pine fen over the growing season using a static chamber method, and CH 4 production and oxidation potentials in peat profiles from hummock and flark were determined in laboratory incubation experiments. Emissions were lowest in the hummocks, and decreased with increasing hummock height, while in the lawns and flarks they increased with increasing sedge cover. Statistical response functions with water table and peat temperature as independent variables were calculated in order to reconstruct seasonal CH 4 emissions by reference to the time series for peat temperature and water table specific to each microsite type. Mean CH 4 emissions in the whole area in the snow-free period of 1993, weighted in terms of the proportions of the microsites, were 1.7 mol CH 4 m -2 . Potential CH 4 production and oxidation rates were very low in the hummocks rising above the groundwater table, but were relatively similar when expressed per dry weight of peat both in the hummocks and flarks below the water table. The CH 4 production potential increased in autumn at both microsites and CH 4 oxidation potential seemed to decrease. The decrease in temperature in autumn certainly reduced in situ decomposition processes, possibly leaving unused substrates in the peat, which would explain the increase in CH 4 production potential.

  14. Rock and Soil Types at Pathfinder Landing Site

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Type areas of rocks and soils. (A) Dark rock type and bright soil type: Shown is the dark rock Barnacle Bill. Reflectance spectra typical of fresh basalt and APXS spectra indicating more silica-rich basaltic andesite compositions characterize this type. These rocks are typically the small boulders and intermediate-sized cobbles at the Pathfinder site. The bright soil type is very common and in this case comprises Barnacle Bill's wind tail and much of the surround soil area. This soil has a high reflectance and a strongly reddened spectrum indicative of oxidized ferric minerals. (B) Bright rock type: Shown is the bright rock Wedge. Reflectance spectra typical of weathered basalt and APXS spectra indicating basaltic compositions characterize this type. These rocks are typically larger than 1 meter in diameter and many display morphologies indicating flood deposition. (C) Pink rock type: Shown is the pink rock Scooby Doo. APXS and reflectance spectra indicate a composition and optical characteristics similar to the drift soil. However, the morphology of the pink rock type indicates a cemented or rocklike structure. This material may be a chemically cemented hardpan that underlies much of the Pathfinder site. (D) Dark soil type: The dark soil type is typically found on the windward sides of rocks or in rock-free areas like Photometry Flats (shown here) where the bright soil has been striped away by aeolian action or in open areas. Other locations include the Mermaid Dune. (E) Disturbed soil type: The darkening of disturbed soil relative to its parent material, bright soil, as a result of changes in soil texture and compaction caused by movement of the rover and retraction of the lander airbag. (F) Lamb-like soil type: This soil type shows reflectance and spectral characteristics intermediate between the bright and dark soils. Its distinguishing feature is a weak spectral absorption near 900 nanometers not seen in either the bright or dark soils.

    NOTE: original

  15. Resonant Column Tests and Nonlinear Elasticity in Simulated Rocks

    NASA Astrophysics Data System (ADS)

    Sebastian, Resmi; Sitharam, T. G.

    2018-01-01

    Rocks are generally regarded as linearly elastic even though the manifestations of nonlinearity are prominent. The variations of elastic constants with varying strain levels and stress conditions, disagreement between static and dynamic moduli, etc., are some of the examples of nonlinear elasticity in rocks. The grain-to-grain contact, presence of pores and joints along with other compliant features induce the nonlinear behavior in rocks. The nonlinear elastic behavior of rocks is demonstrated through resonant column tests and numerical simulations in this paper. Resonant column tests on intact and jointed gypsum samples across varying strain levels have been performed in laboratory and using numerical simulations. The paper shows the application of resonant column apparatus to obtain the wave velocities of stiff samples at various strain levels under long wavelength condition, after performing checks and incorporating corrections to the obtained resonant frequencies. The numerical simulation and validation of the resonant column tests using distinct element method are presented. The stiffness reductions of testing samples under torsional and flexural vibrations with increasing strain levels have been analyzed. The nonlinear elastic behavior of rocks is reflected in the results, which is enhanced by the presence of joints. The significance of joint orientation and influence of joint spacing during wave propagation have also been assessed and presented using the numerical simulations. It has been found that rock joints also exhibit nonlinear behavior within the elastic limit.

  16. Space Weathering of Lunar Rocks and Regolith Grains

    NASA Technical Reports Server (NTRS)

    Keller, L. P.

    2013-01-01

    The exposed surfaces of lunar soil grains and lunar rocks become modified and coated over time with a thin rind of material (patina) through complex interactions with the space environment. These interactions encompass many processes including micrometeorite impacts, vapor and melt deposition, and solar wind implantation/sputtering effects that collectively are referred to as "space weathering". Studies of space weathering effects in lunar soils and rocks provide important clues to understanding the origin and evolution of the lunar regolith as well as aiding in the interpretation of global chemical and mineralogical datasets obtained by remote-sensing missions. The interpretation of reflectance spectra obtained by these missions is complicated because the patina coatings obscure the underlying rock mineralogy and compositions. Much of our understanding of these processes and products comes from decades of work on remote-sensing observations of the Moon, the analysis of lunar samples, and laboratory experiments. Space weathering effects collectively result in a reddened continuum slope, lowered albedo, and attenuated absorption features in reflectance spectra of lunar soils as compared to finely comminuted rocks from the same Apollo sites. Space weathering effects are largely surface-correlated, concentrated in the fine size fractions, and occur as amorphous rims on individual soil grains. Rims on lunar soil grains are highly complex and span the range between erosional surfaces modified by solar wind irradiation to depositional surfaces modified by the condensation of sputtered ions and impact-generated vapors. The optical effects of space weathering effects are directly linked to the production of nanophase Fe metal in lunar materials]. The size of distribution of nanophase inclusions in the rims directly affect optical properties given that large Fe(sup o) grains (approx 10 nm and larger) darken the sample (lower albedo) while the tiny Fe(sup o) grains (<5nm

  17. The Use of Infrared Thermography for Porosity Assessment of Intact Rock

    NASA Astrophysics Data System (ADS)

    Mineo, S.; Pappalardo, G.

    2016-08-01

    Preliminary results on a new test for the indirect assessment of porosity through infrared thermography are presented. The study of the cooling behavior of rock samples in laboratory, through the analysis of thermograms, proved an innovative tool for the estimation of such an important property, which is one of the main features affecting the mechanical behavior of rocks. A detailed experimentation was performed on artificially heated volcanic rock samples characterized by different porosity values. The cooling trend was described both graphically and numerically, with the help of cooling curves and Cooling Rate Index. The latter, which proved strictly linked to porosity, was employed to find reliable equations for its indirect estimation. Simple and multiple regression analyses returned satisfactory outcomes, highlighting the great match between predicted and measured porosity values, thus confirming the goodness of the proposed model. This study brings a novelty in rock mechanics, laying the foundation for future researches aimed at refining achieved results for the validation of the model in a larger scale.

  18. Resolved 12CH2D2 and 13CH3D in CH4 as Sensitive Indicators of Disequilibrium and Equilibrium during Microbial Methane Cycling

    NASA Astrophysics Data System (ADS)

    Ash, J. L.; Egger, M.; Slomp, C. P.; Kohl, I. E.; Treude, T.; Rumble, D.; Young, E. D.

    2016-12-01

    The ability to measure the relative concentrations of at least two doubly-substituted rare isotopologues of gases with biogeochemical relevance provides new constraints on sources and sinks of these gases. In particular, as shown recently for O2, the use of two independent, rare isotopologues allows for detection of thermodynamic intra-species equilibrium and disequilibrium. Here, we report the first measurements of fully resolved 13CH3D and 12CH2D2 from natural samples of microbial methane gas. A suite of sedimentary methane samples from the Bornholm Basin in the Baltic Sea was collected during IODP Exp. 347. Sample depths range from 2-20 meters below seafloor (mbsf). Methane concentrations decrease with depth, and mcrA (a marker for methanogenesis and methanotropy) is present throughout. See Figure. Both Δ13CH3D and Δ12CH2D2 increase with depth as methane concentrations decrease with the shallowest samples exhibiting disequilibrium by up to 2‰ in Δ13CH3D and 13‰ in Δ12CH2D2 while the deepest samples approach isotopic thermodynamic equilibrium (marked by grey bars in Figure). The Fe-mediated anaerobic oxidation of methane (Fe-AOM) has been inferred in these sediments by geochemical modeling . Slow methane cycling by methanogensis and methanotrophy is likely responsible for the approach to isotopic bond order equilibrium in CH4 with depth, consistent with Fe-AOM. While axenic culturing experiments generate methane with large deficits in 12CH2D2 (reported at this meeting), these data from the Baltic Sea demonstrate that isotopic equilibrium can be achieved during microbial recycling of methane. In the absence of Δ12CH2D2, the Δ13CH3D values alone could be misinterpreted as representing gradients in temperature due perhaps to exothermic organic matter degradation. The combination of both mass-18 rare isotopologues of methane provides the means to distinguish equilibrium from disequilibrium and probe microbial methane cycling even where Δ13CH3D suggests

  19. Diminished CAGE Effect in {p}-H2: Infrared Spectra of CH3S Observed from Photolysis of CH3SH, CH3SCH3, and CH3SSCH3 Isolated in {p}-H2

    NASA Astrophysics Data System (ADS)

    Lee, Yuan-Pern; Bahou, Mohammed

    2010-06-01

    We report infrared absorption spectrum of the methylthio (or thiomethoxy) radical, CH3S, isolated in solid {p}-H2. CH3S was produced by in situ UV photodissociation of three precursors: CH3SH, CH3SH3, and CH3SSCH3 isolated in solid {p}-H2. New absorption features commonly observed with similar intensity ratios in experiments using these precursors are assigned as absorption of CH3S. In Addition to the previously assigned transitions of ν 3 (a1) at 727.1 cm-1, fundamental transitions ν 6 (a1) at 771.1, ν 6 (e) at 1056.6, ν 5 (a1) at 1400.0, and &nu 4 (a1) at 2898.0 cm-1 were observed. The wavenumbers of these features agree satisfactorily with those predicted with a spin-vibronic Hamiltonian accounting for the anharmonic effects and the Jahn-Teller effects to the qu rtic term; the corresponding wavenumbers predicted from theory are ν 6 (a1) at 793, ν 6 (e) at 1105, ν 5 (a1) at 1436, and ν 4 (a1) at 2938 cm-1, with deviations of 14-4.6 % from experiments. Previous attempts of UV photolysis of CH3SCH3 and CH3SSCH3 isolated in an Ar matrix failed to produce CH3S. These results serve as an excellent example that the diminished cae effect of solid {p}-H2 makes production of free radicals via photolysis in situ feasible. If time permits, other examples will be discussed. A. V. Marenich and J. E. Boggs, J. Chem. Theory Comput., 1, 1162 (2005).

  20. 68. LITTLE ROCK AND PALMDALE IRRIGATION DISTRICT, LITTLE ROCK DAM: ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    68. LITTLE ROCK AND PALMDALE IRRIGATION DISTRICT, LITTLE ROCK DAM: STRESS SHEET, SHEET 4; MAY, 1918. Littlerock Water District files. - Little Rock Creek Dam, Little Rock Creek, Littlerock, Los Angeles County, CA

  1. Effects of Boreal Lake Wetlands on Atmospheric 13CH3D and 12CH2D2

    NASA Astrophysics Data System (ADS)

    Haghnegahdar, M. A.; Kohl, I. E.; Schauble, E. A.; Walter Anthony, K. M.; Young, E. D.

    2017-12-01

    Recently, we developed a theoretical model to investigate the potential use of 13CH3D and 12CH2D2 as tools for tracking atmospheric methane budget. We used electronic structure methods to estimate kinetic isotope fractionations associated with the major sink reactions of CH4 in air (reactions with •OH and Cl•), and literature data with reconnaissance measurements of the relative abundances of 13CH3D and 12CH2D2 to estimate the compositions of the largest atmospheric sources. Here we present new methane rare isotopologue data from boreal wetlands, comprising one of the most important sources, in order to evaluate the robustness of the model. Boreal wetlands (>55° N) account for more than half of the wetland area in the Northern hemisphere. We analyzed methane samples from high latitude lakes representing different geographical regions, geological and ecological contexts, methane fluxes, and isotopic signatures. Using clumped isotopes of CH4 we are able to determine the likely production mechanism for natural CH4 samples. So far, all of our analyzed samples except one plot in the microbial pure-culture methanogenesis field (Young et al. 2017) with ranges of -0.2‰ to +1.2‰ for Δ13CH3D, and -29.6‰ to -18.2‰ for Δ12CH2D2. These compositions are far from equilibrium. The one exception, from Lake Doughnut, Alaska, exhibits Δ13CH3D and Δ12CH2D2 values of +5.2‰ and +18.7‰, respectively, which fall near ambient thermodynamic equilibrium values. This may be an effect of methanotrophy. Mean Δ13CH3D and Δ12CH2D2 for all lake samples are +1.7‰ and -15.4‰ respectively, compared to our original estimate of +6.1‰ and +21.2‰ for the wetland methane source based on an assumption of equilibrium. If we assume that these samples are representative of the overall wetland source, Δ13CH3D decreases by 0.8‰ and Δ12CH2D2 decreases by 0.6‰ in our model of bulk atmospheric methane. Δ13CH3D and Δ12CH2D2 values of air (including •OH and Cl• sink

  2. Arrhenius Behavior of Electron Attachment to CH3Br from 303 to 1100 K

    DTIC Science & Technology

    2013-12-21

    Spectrometry journa l homepage: www.e lsev ier .com/ locate / i jms rrhenius behavior of electron attachment to CH3Br from 03 to 1100K homas M. Miller1...Nicholas S. Shuman, Albert A. Viggiano ∗ ir Force Research Laboratory, Space Vehicles Directorate, Kirtland Air Force Base, NM 87117-5776, USA r t i

  3. Spectral Characteristics of Continuous Acoustic Emission (AE) Data from Laboratory Rock Deformation Experiments

    NASA Astrophysics Data System (ADS)

    Flynn, J. William; Goodfellow, Sebastian; Reyes-Montes, Juan; Nasseri, Farzine; Young, R. Paul

    2016-04-01

    Continuous acoustic emission (AE) data recorded during rock deformation tests facilitates the monitoring of fracture initiation and propagation due to applied stress changes. Changes in the frequency and energy content of AE waveforms have been previously observed and were associated with microcrack coalescence and the induction or mobilisation of large fractures which are naturally associated with larger amplitude AE events and lower-frequency components. The shift from high to low dominant frequency components during the late stages of the deformation experiment, as the rate of AE events increases and the sample approaches failure, indicates a transition from the micro-cracking to macro-cracking regime, where large cracks generated result in material failure. The objective of this study is to extract information on the fracturing process from the acoustic records around sample failure, where the fast occurrence of AE events does not allow for identification of individual AE events and phase arrivals. Standard AE event processing techniques are not suitable for extracting this information at these stages. Instead the observed changes in the frequency content of the continuous record can be used to characterise and investigate the fracture process at the stage of microcrack coalescence and sample failure. To analyse and characterise these changes, a detailed non-linear and non-stationary time-frequency analysis of the continuous waveform data is required. Empirical Mode Decomposition (EMD) and Hilbert Spectral Analysis (HSA) are two of the techniques used in this paper to analyse the acoustic records which provide a high-resolution temporal frequency distribution of the data. In this paper we present the results from our analysis of continuous AE data recorded during a laboratory triaxial deformation experiment using the combined EMD and HSA method.

  4. Air and groundwater flow at the interface between fractured host rock and a bentonite buffer

    NASA Astrophysics Data System (ADS)

    Dessirier, B.; Jarsjo, J.; Frampton, A.

    2014-12-01

    Designs of deep geological repositories for spent nuclear fuel include several levels of confinement. The Swedish and Finnish concept KBS-3 targets for example sparsely fractured crystalline bedrock as host formation and would have the waste canisters embedded in an engineered buffer of compacted MX-80 bentonite. The host rock is a highly heterogeneous dual porosity material containing fractures and a rock matrix. Bentonite is a complex expansive porous material. Its water content and mechanical properties are interdependent. Beyond the specific physics of unsaturated flow and transport in each medium, the interface between them is critical. Detailed knowledge of the transitory two-phase flow regime, induced by the insertion of the unsaturated buffer in a saturated rock environment, is necessary to assess the performance of planned KBS-3 deposition holes. A set of numerical simulations based on the equations of two-phase flow for water and air in porous media were conducted to investigate the dynamics of air and groundwater flow near the rock/bentonite interface in the period following installation of the unsaturated bentonite buffer. We assume state of the two-phase flow parameter values for bentonite from laboratory water uptake tests and typical fracture and rock properties from the Äspö Hard rock laboratory (Sweden) gathered under several field characterization campaigns. The results point to desaturation of the rock domain as far as 10 cm away from the interface into matrix-dominated regions for up to 160 days. Similar observations were made during the Bentonite Rock Interaction Experiment (BRIE) at the Äspö HRL, with a desaturation sustained for even longer times. More than the mere time to mechanical and hydraulic equilibrium, the occurrence of sustained unsaturated conditions opens the possibility for biogeochemical processes that could be critical in the safety assessment of the planned repository.

  5. ChIPWig: a random access-enabling lossless and lossy compression method for ChIP-seq data.

    PubMed

    Ravanmehr, Vida; Kim, Minji; Wang, Zhiying; Milenkovic, Olgica

    2018-03-15

    Chromatin immunoprecipitation sequencing (ChIP-seq) experiments are inexpensive and time-efficient, and result in massive datasets that introduce significant storage and maintenance challenges. To address the resulting Big Data problems, we propose a lossless and lossy compression framework specifically designed for ChIP-seq Wig data, termed ChIPWig. ChIPWig enables random access, summary statistics lookups and it is based on the asymptotic theory of optimal point density design for nonuniform quantizers. We tested the ChIPWig compressor on 10 ChIP-seq datasets generated by the ENCODE consortium. On average, lossless ChIPWig reduced the file sizes to merely 6% of the original, and offered 6-fold compression rate improvement compared to bigWig. The lossy feature further reduced file sizes 2-fold compared to the lossless mode, with little or no effects on peak calling and motif discovery using specialized NarrowPeaks methods. The compression and decompression speed rates are of the order of 0.2 sec/MB using general purpose computers. The source code and binaries are freely available for download at https://github.com/vidarmehr/ChIPWig-v2, implemented in C ++. milenkov@illinois.edu. Supplementary data are available at Bioinformatics online.

  6. Martian and Terrestrial Rock Abrasion from Wind Tunnel and Field Studies

    NASA Technical Reports Server (NTRS)

    Bridges, N. T.; Greeley, R.; Eddlemon, E.; Laity, J. E.; Meyer, C.; Phoreman, J.; White, B. R.

    2003-01-01

    Earth and Mars exhibit ventifacts, rocks that have been abraded by saltating sand. Previous theoretical and laboratory studies have determined abrasion susceptibilities of rocks as a function of sand type and impact angle and rock material strengths. For the last two years we have been engaged in wind tunnel and field studies to better understand the fundamental factors which control and influence rock abrasion and ventifact formation on Earth and Mars. In particular, we are examining: 1) What types of rocks (composition, texture, and shape) preferentially erode and what are the relative rates of one type vs. another? 2) What are the controlling factors of the aeolian sand cloud (flux, particle speed, surface roughness, etc) which favor rock abrasion?, 3) How do specific ventifact characteristics tie into their mode of formation and rock properties? We find several important factors: 1) Initial rock shape controls the rate of abrasion, with steeper faces abrading faster than shallower ones. The relationship is partly dependent on angle-dependent flux (proportional to sin[theta]) but exhibits additional non-linear effects from momentum transfer efficiency and rebound effects that vary with incidence angle. 2) Irregular targets with pits or grooves abrade at greater rates than targets with smooth surfaces, with indentations generally enlarging with time. Surfaces become rougher with time. 3) Targets also abrade via slope retreat, which is roughly dependent on the slope of the front face. The formation of basal sills is common, as observed on terrestrial and Martian ventifacts.

  7. A sampling study on rock properties affecting drilling rate index (DRI)

    NASA Astrophysics Data System (ADS)

    Yenice, Hayati; Özdoğan, Mehmet V.; Özfırat, M. Kemal

    2018-05-01

    Drilling rate index (DRI) developed in Norway is a very useful index in determining the drillability of rocks and even in performance prediction of hard rock TBMs and it requires special laboratory test equipment. Drillability is one of the most important subjects in rock excavation. However, determining drillability index from physical and mechanical properties of rocks is very important for practicing engineers such as underground excavation, drilling operations in open pit mining, underground mining and natural stone production. That is why many researchers have studied concerned with drillability to find the correlations between drilling rate index (DRI) and penetration rate, influence of geological properties on drillability prediction in tunneling, correlations between rock properties and drillability. In this study, the relationships between drilling rate index (DRI) and some physico-mechanical properties (Density, Shore hardness, uniaxial compressive strength (UCS, σc), Indirect tensile strength (ITS, σt)) of three different rock groups including magmatic, sedimentary and metamorphic were evaluated using both simple and multiple regression analysis. This study reveals the effects of rock properties on DRI according to different types of rocks. In simple regression, quite high correlations were found between DRI and uniaxial compressive strength (UCS) and also between DRI and indirect tensile strength (ITS) values. Multiple regression analyses revealed even higher correlations when compared to simple regression. Especially, UCS, ITS, Shore hardness (SH) and the interactions between them were found to be very effective on DRI values.

  8. Permeability of volcanic rocks to gas and water

    NASA Astrophysics Data System (ADS)

    Heap, M. J.; Reuschlé, T.; Farquharson, J. I.; Baud, P.

    2018-04-01

    The phase (gas or liquid) of the fluids within a porous volcanic system varies in both time and space. Laboratory experiments have shown that gas and water permeabilities can differ for the same rock sample, but experiments are biased towards rocks that contain minerals that are expected react with the pore fluid (such as the reaction between liquid water and clay). We present here the first study that systematically compares the gas and water permeability of volcanic rocks. Our data show that permeabilities to argon gas and deionised water can differ by a factor between two and five in two volcanic rocks (basalt and andesite) over a confining pressure range from 2 to 50 MPa. We suggest here that the microstructural elements that offer the shortest route through the sample-estimated to have an average radius 0.1-0.5 μm using the Klinkenberg slip factor-are accessible to gas, but restricted or inaccessible to water. We speculate that water adsorption on the surface of these thin microstructural elements, assumed here to be tortuous/rough microcracks, reduces their effective radius and/or prevents access. These data have important implications for fluid flow and therefore the distribution and build-up of pore pressure within volcanic systems.

  9. Elastic Rock Heterogeneity Controls Brittle Rock Failure during Hydraulic Fracturing

    NASA Astrophysics Data System (ADS)

    Langenbruch, C.; Shapiro, S. A.

    2014-12-01

    For interpretation and inversion of microseismic data it is important to understand, which properties of the reservoir rock control the occurrence probability of brittle rock failure and associated seismicity during hydraulic stimulation. This is especially important, when inverting for key properties like permeability and fracture conductivity. Although it became accepted that seismic events are triggered by fluid flow and the resulting perturbation of the stress field in the reservoir rock, the magnitude of stress perturbations, capable of triggering failure in rocks, can be highly variable. The controlling physical mechanism of this variability is still under discussion. We compare the occurrence of microseismic events at the Cotton Valley gas field to elastic rock heterogeneity, obtained from measurements along the treatment wells. The heterogeneity is characterized by scale invariant fluctuations of elastic properties. We observe that the elastic heterogeneity of the rock formation controls the occurrence of brittle failure. In particular, we find that the density of events is increasing with the Brittleness Index (BI) of the rock, which is defined as a combination of Young's modulus and Poisson's ratio. We evaluate the physical meaning of the BI. By applying geomechanical investigations we characterize the influence of fluctuating elastic properties in rocks on the probability of brittle rock failure. Our analysis is based on the computation of stress fluctuations caused by elastic heterogeneity of rocks. We find that elastic rock heterogeneity causes stress fluctuations of significant magnitude. Moreover, the stress changes necessary to open and reactivate fractures in rocks are strongly related to fluctuations of elastic moduli. Our analysis gives a physical explanation to the observed relation between elastic heterogeneity of the rock formation and the occurrence of brittle failure during hydraulic reservoir stimulations. A crucial factor for understanding

  10. Rock.XML - Towards a library of rock physics models

    NASA Astrophysics Data System (ADS)

    Jensen, Erling Hugo; Hauge, Ragnar; Ulvmoen, Marit; Johansen, Tor Arne; Drottning, Åsmund

    2016-08-01

    Rock physics modelling provides tools for correlating physical properties of rocks and their constituents to the geophysical observations we measure on a larger scale. Many different theoretical and empirical models exist, to cover the range of different types of rocks. However, upon reviewing these, we see that they are all built around a few main concepts. Based on this observation, we propose a format for digitally storing the specifications for rock physics models which we have named Rock.XML. It does not only contain data about the various constituents, but also the theories and how they are used to combine these building blocks to make a representative model for a particular rock. The format is based on the Extensible Markup Language XML, making it flexible enough to handle complex models as well as scalable towards extending it with new theories and models. This technology has great advantages as far as documenting and exchanging models in an unambiguous way between people and between software. Rock.XML can become a platform for creating a library of rock physics models; making them more accessible to everyone.

  11. Hydrogen Peroxide Formation and pH Changes at Rock-Water Interface during Stressing

    NASA Astrophysics Data System (ADS)

    Xie, S.; Kulahci, I.; Cyr, G.; Tregloan-Reed, J.; Balk, M.; Rothschild, L. J.; Freund, F. T.

    2008-12-01

    Common igneous and high-grade metamorphic rocks contain dormant defects, which become activated when stressed. They release electronic charge carriers, in particular defect electrons associated with O- states in a matrix of O2-. Known as 'positive holes' or pholes for short, the O- states can spread out of the stressed rock volume, travel along stress gradients over distances on the order of meters in the lab and probably over kilometers in the field. They carry a current, which can flow through meters of rock in the laboratory, probably tens of kilometers in the field. At rock-water interfaces the O- states turn into O radicals, which subtract H from H2O, forming OH- in the rock surface and PH radicals in the water. Two OH combine to H2O2. In the process the pH becomes more acidic. The discovery of H2O2 formation at rock-water interfaces as part of stress- activated currents on the tectonically active Earth may help us better understand the oxidation of the early Earth and the evolution of early Life.

  12. Constitutive Modeling of the Thermomechanical Behavior of Rock Salt

    NASA Astrophysics Data System (ADS)

    Hampel, A.

    2016-12-01

    For the safe disposal of heat-generating high-level radioactive waste in rock salt formations, highly reliable numerical simulations of the thermomechanical and hydraulic behavior of the host rock have to be performed. Today, the huge progress in computer technology has enabled experts to calculate large and detailed computer models of underground repositories. However, the big ad­van­ces in computer technology are only beneficial when the applied material models and modeling procedures also meet very high demands. They result from the fact that the evaluation of the long-term integrity of the geological barrier requires an extra­polation of a highly nonlinear deforma­tion behavior to up to 1 million years, while the underlying experimental investigations in the laboratory or in situ have a duration of only days, weeks or at most some years. Several advanced constitutive models were developed and continuously improved to describe the dependences of various deformation phenomena in rock salt on in-situ relevant boundary conditions: transient and steady-state creep, evolution of damage and dilatancy in the DRZ, failure, post-failure behavior, residual strength, damage and dilatancy reduction, and healing. In a joint project series between 2004 and 2016, fundamental features of the advanced models were investigated and compared in detail with benchmark calculations. The study included procedures for the determination of characteristic salt-type-specific model parameter values and for the performance of numerical calculations of underground structures. Based on the results of this work and on specific laboratory investigations, the rock mechanical modeling is currently developed further in a common research project of experts from Germany and the United States. In this presentation, an overview about the work and results of the project series is given and the current joint research project WEIMOS is introduced.

  13. Design of Rock Slope Reinforcement: An Himalayan Case Study

    NASA Astrophysics Data System (ADS)

    Tiwari, Gaurav; Latha, Gali Madhavi

    2016-06-01

    The stability analysis of the two abutment slopes of a railway bridge proposed at about 359 m above the ground level, crossing a river and connecting two hill faces in the Himalayas, India, is presented. The bridge is located in a zone of high seismic activity. The rock slopes are composed of a heavily jointed rock mass and the spacing, dip and dip direction of joint sets are varying at different locations. Geological mapping was carried out to characterize all discontinuities present along the slopes. Laboratory and field investigations were conducted to assess the geotechnical properties of the intact rock, rock mass and joint infill. Stability analyses of these rock slopes were carried out using numerical programmes. Loads from the foundations resting on the slopes and seismic accelerations estimated from site-specific ground response analysis were considered. The proposed slope profile with several berms between successive foundations was simulated in the numerical model. An equivalent continuum approach with Hoek and Brown failure criterion was initially used in a finite element model to assess the global stability of the slope abutments. In the second stage, finite element analysis of rock slopes with all joint sets with their orientations, spacing and properties explicitly incorporated into the numerical model was taken up using continuum with joints approach. It was observed that the continuum with joints approach was able to capture the local failures in some of the slope sections, which were verified using wedge failure analysis and stereographic projections. Based on the slope deformations and failure patterns observed from the numerical analyses, rock anchors were designed to achieve the target factors of safety against failure while keeping the deformations within the permissible limits. Detailed design of rock anchors and comparison of the stability of slopes with and without reinforcement are presented.

  14. Seasonal patterns in body temperature of free-living rock hyrax (Procavia capensis).

    PubMed

    Brown, Kelly J; Downs, Colleen T

    2006-01-01

    Rock hyrax (Procavia capensis) are faced with large daily fluctuations in ambient temperature during summer and winter. In this study, peritoneal body temperature of free-living rock hyrax was investigated. During winter, when low ambient temperatures and food supply prevail, rock hyrax maintained a lower core body temperature relative to summer. In winter body temperatures during the day were more variable than at night. This daytime variability is likely a result of body temperatures being raised from basking in the sun. Body temperatures recorded during winter never fell to low levels recorded in previous laboratory studies. During summer ambient temperatures exceeded the thermoneutral zone of the rock hyrax throughout most of the day, while crevice temperatures remained within the thermoneutral zone of rock hyrax. However, in summer variation in core body temperature was small. Minimum and maximum body temperatures did not coincide with minimum and maximum ambient temperatures. Constant body temperatures were also recorded when ambient temperatures reached lethal limits. During summer it is likely that rock hyrax select cooler refugia to escape lethal temperatures and to prevent excessive water loss. Body temperature of rock hyrax recorded in this study reflects the adaptability of this animal to the wide range of ambient temperatures experienced in its natural environment.

  15. Modeling rock specimens through 3D printing: Tentative experiments and prospects

    NASA Astrophysics Data System (ADS)

    Jiang, Quan; Feng, Xiating; Song, Lvbo; Gong, Yahua; Zheng, Hong; Cui, Jie

    2016-02-01

    Current developments in 3D printing (3DP) technology provide the opportunity to produce rock-like specimens and geotechnical models through additive manufacturing, that is, from a file viewed with a computer to a real object. This study investigated the serviceability of 3DP products as substitutes for rock specimens and rock-type materials in experimental analysis of deformation and failure in the laboratory. These experiments were performed on two types of materials as follows: (1) compressive experiments on printed sand-powder specimens in different shapes and structures, including intact cylinders, cylinders with small holes, and cuboids with pre-existing cracks, and (2) compressive and shearing experiments on printed polylactic acid cylinders and molded shearing blocks. These tentative tests for 3DP technology have exposed its advantages in producing complicated specimens with special external forms and internal structures, the mechanical similarity of its product to rock-type material in terms of deformation and failure, and its precision in mapping shapes from the original body to the trial sample (such as a natural rock joint). These experiments and analyses also successfully demonstrate the potential and prospects of 3DP technology to assist in the deformation and failure analysis of rock-type materials, as well as in the simulation of similar material modeling experiments.

  16. Experimental Studies on the Mechanical Behaviour of Rock Joints with Various Openings

    NASA Astrophysics Data System (ADS)

    Li, Y.; Oh, J.; Mitra, R.; Hebblewhite, B.

    2016-03-01

    The mechanical behaviour of rough joints is markedly affected by the degree of joint opening. A systematic experimental study was conducted to investigate the effect of the initial opening on both normal and shear deformations of rock joints. Two types of joints with triangular asperities were produced in the laboratory and subjected to compression tests and direct shear tests with different initial opening values. The results showed that opened rock joints allow much greater normal closure and result in much lower normal stiffness. A semi-logarithmic law incorporating the degree of interlocking is proposed to describe the normal deformation of opened rock joints. The proposed equation agrees well with the experimental results. Additionally, the results of direct shear tests demonstrated that shear strength and dilation are reduced because of reduced involvement of and increased damage to asperities in the process of shearing. The results indicate that constitutive models of rock joints that consider the true asperity contact area can be used to predict shear resistance along opened rock joints. Because rock masses are loosened and rock joints become open after excavation, the model suggested in this study can be incorporated into numerical procedures such as finite-element or discrete-element methods. Use of the model could then increase the accuracy and reliability of stability predictions for rock masses under excavation.

  17. Microscopic Study of Rocks and Minerals in Introductory Geology Courses.

    ERIC Educational Resources Information Center

    Singh, Raman J.

    1983-01-01

    Suggests that introductory geology students, who are mostly nonmajors, would benefit if more laboratory time and the necessary microscopic examination were allowed as part of work on rocks/minerals. Indicates that students need to be taught value/necessity of paying attention to details while gathering data or making observations to make…

  18. "Rock Garden"

    NASA Image and Video Library

    1997-10-14

    This false color composite image of the Rock Garden shows the rocks "Shark" and "Half Dome" at upper left and middle, respectively. Between these two large rocks is a smaller rock (about 0.20 m wide, 0.10 m high, and 6.33 m from the Lander) that was observed close-up with the Sojourner rover (see PIA00989). http://photojournal.jpl.nasa.gov/catalog/PIA00987

  19. Radionuclide migration: laboratory experiments with isolated fractures

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rundberg, R.S.; Thompson, J.L.; Maestas, S.

    Laboratory experiments examining flow and element migration in rocks containing isolated fractures have been initiated at the Los Alamos National Laboratory. Techniques are being developed to establish simple fracture flow systems which are appropriate to models using analytical solutions to the matrix diffusion-flow equations, such as those of I. Neretnieks [I. Neretnieks, Diffusion in the Rock Matrix: An Important Factor in Radionuclide Retardation? J. Geophys. Res. 85, 4379 (1980).] These experiments are intended to be intermediate steps toward larger scale field experiments where it may become more difficult to establish and control the parameters important to nuclide migration in fracturedmore » media. Laboratory experiments have been run on fractures ranging in size from 1 to 20 cm in length. The hydraulic flow in these fractures was studied to provide the effective apertures. The flows established in these fracture systems are similar to those in the granite fracture flow experiments of Witherspoon et al. [P.A. Witherspoon, J.S.Y. Wang, K. Iwai, and J.E. Gale, Validity of Cubic Law for Fluid Flow in a Deformable Rock Fracture, Lawrence Berkeley Laboratory report LBL-9557 (October 1979).] Traced solutions containing {sup 85}Sr and {sup 137}Cs were flowed through fractures in Climax Stock granite and welded tuff (Bullfrog and Tram members, Yucca Mountain, Nevada Test Site). The results of the elutions through granite agree with the matrix diffusion calculations based on independent measurements of K/sub d/. The results of the elutions through tuff, however, agree only if the K/sub d/ values used in the calculations are lower than the K/sub d/ values measured using a batch technique. This trend has been previously observed in chromatographic column experiments with tuff. 5 figures, 3 tables.« less

  20. The Possible Interstellar Anion CH2CN-: Spectroscopic Constants, Vibrational Frequencies, and Other Considerations

    NASA Technical Reports Server (NTRS)

    Fortenberry, Ryan C.; Crawford, T. Daniel; Lee, Timothy J.

    2012-01-01

    The A 1B1 <-1A0 excitation into the dipole-bound state of the cyanomethyl anion (CH2CN??) has been hypothesized as the carrier for one di use interstellar band. However, this particular molecular system has not been detected in the interstellar medium even though the related cyanomethyl radical and the isoelectronic ketenimine molecule have been found. In this study we are employing the use of proven quartic force elds and second-order vibrational perturbation theory to compute accurate spectroscopic constants and fundamental vibrational frequencies for X 1A0 CH2CN?? in order to assist in laboratory studies and astronomical observations. Keywords: Astrochemistry, ISM: molecular anions, Quartic force elds, Rotational constants, Vibrational frequencies

  1. Rock weathering by indigenous heterotrophic bacteria of Bacillus spp. at different temperature: a laboratory experiment

    NASA Astrophysics Data System (ADS)

    Štyriaková, I.; Štyriak, I.; Oberhänsli, H.

    2012-07-01

    The bio-weathering of basalt, granite and gneiss was experimentally investigated in this study. These rock-forming minerals weathered more rapidly via the ubiquitous psychrotrophic heterotrophic bacteria . With indigenous bacteria of Bacillus spp. from sediments of Lake Baikal, we traced the degradation process of silicate minerals to understand the weathering processes occurring at the change temperature in the subsurface environment with organic input. The bacteria mediated dissolution of minerals was monitored with solution and solid chemistry, X-ray analyses as well as microscopic techniques. We determined the impact of the bacteria on the mineral surface and leaching of K, Ca, Mg, Si, Fe, and Al from silicate minerals. In the samples the release of major structural elements of silicates was used as an overall indicator of silicate mineral degradation at 4°C and 18°C from five medium exchanges over 255 days of rock bioleaching. The increase of temperature importantly affected the efficiency of Fe extraction from granite and basalt as well as Si extraction from granite and gneiss. In comparison with elemental extraction order at 4°C, Ca was substituted first by Fe or Si. It is evident that temperature influences rock microbial weathering and results in a change of elements extraction.

  2. Martian CH(4): sources, flux, and detection.

    PubMed

    Onstott, T C; McGown, D; Kessler, J; Lollar, B Sherwood; Lehmann, K K; Clifford, S M

    2006-04-01

    Recent observations have detected trace amounts of CH(4) heterogeneously distributed in the martian atmosphere, which indicated a subsurface CH(4) flux of ~2 x 10(5) to 2 x 10(9) cm(2) s(1). Four different origins for this CH(4) were considered: (1) volcanogenic; (2) sublimation of hydrate- rich ice; (3) diffusive transport through hydrate-saturated cryosphere; and (4) microbial CH(4) generation above the cryosphere. A diffusive flux model of the martian crust for He, H(2), and CH(4) was developed based upon measurements of deep fracture water samples from South Africa. This model distinguishes between abiogenic and microbial CH(4) sources based upon their isotopic composition, and couples microbial CH(4) production to H(2) generation by H(2)O radiolysis. For a He flux of approximately 10(5) cm(2) s(1) this model yields an abiogenic CH(4) flux and a microbial CH(4) flux of approximately 10(6) and approximately 10(9) cm(2) s(1), respectively. This flux will only reach the martian surface if CH(4) hydrate is saturated in the cryosphere; otherwise it will be captured within the cryosphere. The sublimation of a hydrate-rich cryosphere could generate the observed CH(4) flux, whereas microbial CH(4) production in a hypersaline environment above the hydrate stability zone only seems capable of supplying approximately 10(5) cm(2) s(1) of CH(4). The model predicts that He/H(2)/CH(4)/C(2)H(6) abundances and the C and H isotopic values of CH(4) and the C isotopic composition of C(2)H(6) could reveal the different sources. Cavity ring-down spectrometers represent the instrument type that would be most capable of performing the C and H measurements of CH(4) on near future rover missions and pinpointing the cause and source of the CH(4) emissions.

  3. Synchrotron Photoionization Study of Furan and 2-Methylfuran Reactions with Methylidyne Radical (CH) at 298 K.

    PubMed

    Carrasco, Erica; Smith, Kenneth J; Meloni, Giovanni

    2018-01-11

    The reactions of furan and 2-methylfuran with methylidyne CH (X 2 Π) radical were investigated at 298 K using synchrotron radiation produced at the Advanced Light Source of the Lawrence Berkeley National Laboratory. Reaction products were observed by multiplexed photoionization mass spectrometry and characterized based on their photoionization spectra and kinetic time traces. Primary products observed in furan + CH are 2,4-cyclopentadien-1-one (m/z = 80), 2-penten-4-ynal (m/z = 80), and vinylacetylene (m/z = 52). From 2-methylfuran + CH, 2-4-cyclopentadien-1-carbaldehyde (m/z = 94), 2,3,4-hexatrienal (m/z = 94), 1,3 cyclopentadiene (m/z = 66), 3-penten-1-yne (Z) (m/z = 66), and vinylacetylene (m/z = 52) are the primary products observed. Using potential energy surface scans, thermodynamically favorable reaction pathways are proposed. CH addition to the π-bonds in furan and 2-methylfuran rings was found to be the entrance channel that led to formation of all identified primary products. Both reactions follow patterns of H loss and CHO loss, as well as formation of cyclic and acyclic isomers.

  4. Rock burst governance of working face under igneous rock

    NASA Astrophysics Data System (ADS)

    Chang, Zhenxing; Yu, Yue

    2017-01-01

    As a typical failure phenomenon, rock burst occurs in many mines. It can not only cause the working face to cease production, but also cause serious damage to production equipment, and even result in casualties. To explore how to govern rock burst of working face under igneous rock, the 10416 working face in some mine is taken as engineering background. The supports damaged extensively and rock burst took place when the working face advanced. This paper establishes the mechanical model and conducts theoretical analysis and calculation to predict the fracture and migration mechanism and energy release of the thick hard igneous rock above the working face, and to obtain the advancing distance of the working face when the igneous rock fractures and critical value of the energy when rock burst occurs. Based on the specific conditions of the mine, this paper put forward three kinds of governance measures, which are borehole pressure relief, coal seam water injection and blasting pressure relief.

  5. Correlation of field seismic refraction data with 3-D laboratory ultrasonic sounding data during exploration of a dimension stone deposit

    NASA Astrophysics Data System (ADS)

    Přikryl, Richard; Vilhelm, Jan; Lokajíček, Tomáš; Pros, Zdeněk; Klíma, Karel

    2004-05-01

    Multidirectional field seismic refraction data have been combined with 3-D laboratory ultrasonic sounding data in a preliminary exploration of a new dimension stone deposit in the Czech Republic. Rock fabric was interpreted from a detailed laboratory analysis of a 3-D P-wave velocity pattern and can be classified as pronounced orthorhombic due to a complex tectonometamorphic history of the rock. The P-wave velocity pattern recorded from laboratory measurements can be satisfactorily correlated with the anisotropy of P-wave velocity data acquired from field seismic refraction data. Rock fabric anisotropy also contributes to the observed anisotropy of strength and static deformational properties.

  6. The atmospheric degradation of methyl isocyanate (CH3NCO), a toxic substance

    NASA Astrophysics Data System (ADS)

    Papanastasiou, D. K.; Bernard, F.; Burkholder, J. B.

    2016-12-01

    Alkyl isocyanates (R-NCO), as well as isocyanic acid (HNCO), are toxic substances that are emitted into the atmosphere during incomplete combustion of biomass and also formed as products in the atmospheric photooxidation of nitrogen-containing organic species. For example, methyl isocyanate (MIC, CH3NCO) is formed in the atmospheric photochemical transformation of methylisothiocyanate (CH3NCS), a widely used soil fumigant, as well as in the atmospheric photooxidation of amides, such as N-methylformamide. MIC is of particular interest to society because of the possible exposure to this toxic trace compound (recommended exposure limit is 0.02 ppm) in the aftermath of fumigation. Although, there are limited observations of atmospheric MIC (mostly nearby agricultural/fumigation activities) the possibility of emission from combustion processes, such as wildfires, warrants future study. The atmospheric lifetime and fate (gas phase and heterogeneous chemistry) of CH3NCO are presently not well characterized with only a single study of the OH + CH3NCO reaction rate coefficient available in the literature. Additional results from fundamental laboratory studies regarding the major atmospheric degradation pathways of MIC are needed for input to air quality, health, and environmental impact studies. In this study, the reaction of CH3NCO with OH radicals was investigated using pulsed laser photolysis coupled with laser induced fluorescence detection of the OH radical. The rate coefficients, k(OH+CH3NCO), were determined over a range of temperature (295-375 K) and pressure (40-100 Torr, He). The present results are in significant disagreement with the recently published relative rate study. A relative rate kinetic method was also used in this study for comparison and the problems associated with these measurements will be discussed. The atmospheric lifetime of MIC with respect to its gas-phase reaction with OH radicals is estimated to be 85 days, which implies the possibility for

  7. Contrast between the mechanisms for dissociative electron attachment to CH3SCN and CH3NCS.

    PubMed

    Miller, Thomas M; Viggiano, Albert A; Shuman, Nicholas S

    2018-05-14

    The kinetics of thermal electron attachment to methyl thiocyanate (CH 3 SCN), methyl isothiocyanate (CH 3 NCS), and ethyl thiocyanate (C 2 H 5 SCN) were measured using flowing afterglow-Langmuir probe apparatuses at temperatures between 300 and 1000 K. CH 3 SCN and C 2 H 5 SCN undergo inefficient dissociative attachment to yield primarily SCN - at 300 K (k = 2 × 10 -10 cm 3 s -1 ), with increasing efficiency as temperature increases. The increase is well described by activation energies of 0.17 eV (CH 3 SCN) and 0.14 eV (C 2 H 5 SCN). CN - product is formed at <1% branching at 300 K, increasing to ∼30% branching at 1000 K. Attachment to CH 3 NCS yields exclusively SCN - ionic product but at a rate at 300 K that is below our detection threshold (k < 10 -12 cm 3 s -1 ). The rate coefficient increases rapidly with increasing temperature (k = 6 × 10 -11 cm 3 s -1 at 600 K), in a manner well described by an activation energy of 0.51 eV. Calculations at the B3LYP/def2-TZVPPD level suggest that attachment to CH 3 SCN proceeds through a dissociative state of CH 3 SCN - , while attachment to CH 3 NCS initially forms a weakly bound transient anion CH 3 NCS -* that isomerizes over an energetic barrier to yield SCN - . Kinetic modeling of the two systems is performed in an attempt to identify a kinetic signature differentiating the two mechanisms. The kinetic modeling reproduces the CH 3 NCS data only if dissociation through the transient anion is considered.

  8. Contrast between the mechanisms for dissociative electron attachment to CH3SCN and CH3NCS

    NASA Astrophysics Data System (ADS)

    Miller, Thomas M.; Viggiano, Albert A.; Shuman, Nicholas S.

    2018-05-01

    The kinetics of thermal electron attachment to methyl thiocyanate (CH3SCN), methyl isothiocyanate (CH3NCS), and ethyl thiocyanate (C2H5SCN) were measured using flowing afterglow-Langmuir probe apparatuses at temperatures between 300 and 1000 K. CH3SCN and C2H5SCN undergo inefficient dissociative attachment to yield primarily SCN- at 300 K (k = 2 × 10-10 cm3 s-1), with increasing efficiency as temperature increases. The increase is well described by activation energies of 0.17 eV (CH3SCN) and 0.14 eV (C2H5SCN). CN- product is formed at <1% branching at 300 K, increasing to ˜30% branching at 1000 K. Attachment to CH3NCS yields exclusively SCN- ionic product but at a rate at 300 K that is below our detection threshold (k < 10-12 cm3 s-1). The rate coefficient increases rapidly with increasing temperature (k = 6 × 10-11 cm3 s-1 at 600 K), in a manner well described by an activation energy of 0.51 eV. Calculations at the B3LYP/def2-TZVPPD level suggest that attachment to CH3SCN proceeds through a dissociative state of CH3SCN-, while attachment to CH3NCS initially forms a weakly bound transient anion CH3NCS-* that isomerizes over an energetic barrier to yield SCN-. Kinetic modeling of the two systems is performed in an attempt to identify a kinetic signature differentiating the two mechanisms. The kinetic modeling reproduces the CH3NCS data only if dissociation through the transient anion is considered.

  9. The stripping of penetration 85-100 asphalt from silicate aggregate rocks : a laboratory study.

    DOT National Transportation Integrated Search

    1972-01-01

    In Virginia stripping has occurred when certain of the acidic silicate rocks have been used as aggregate in bituminous paving. The purpose of this project was to discover which kinds of silicate aggregate would be most apt to remain well bonded in bi...

  10. Wing Rock Motion and its Flow Mechanism over a Chined-Body Configuration

    NASA Astrophysics Data System (ADS)

    Wang, Yankui; Li, Qian; Shi, Wei

    2015-11-01

    Wing rock motion is one kind of uncommanded oscillation around the body axis over the most of the aircraft at enough high angle of attack and has a strong threat to the flight safety. The purpose of this paper is to investigate the wing rock motion over a typical body-wing configuration with a chined fuselage at fixed angle of attack firstly and four kinds of wing rock motion are revealed based on the flow phenomena, namely non-oscillation, lateral deflection, limit-cycle oscillation and irregular oscillation. Simultaneously, some special relationship between the wing rock motion and the flow over the chined body configuration are discussed. In addition, the evolution of wing rock motion and its corresponding flows when the model undergoes pitching up are also given out. All the experiments have been conducted in a low-speed wind tunnel at a Reynolds number of 1.87*10E5 and angle of attack from 0deg to 65deg. National Natural Science Foundation of China(11472028) and Open fund from State Key Laboratory of Aerodynamics.

  11. Geotechnical Descriptions of Rock and Rock Masses.

    DTIC Science & Technology

    1985-04-01

    determined in the field on core speci ns by the standard Rock Testing Handbook Methods . afls GA DTIC TAB thannounod 13 Justifiatlo By Distributin...to provide rock strength descriptions from the field. The point-load test has proven to be a reliable method of determining rock strength properties...report should qualify the reported spacing values by stating the methods used to determine spacing. Preferably the report should make the determination

  12. Note: CO₂-mineral dissolution experiments using a rocking autoclave and a novel titanium reaction cell.

    PubMed

    Purser, Gemma; Rochelle, Christopher A; Wallis, Humphrey C; Rosenqvist, Jörgen; Kilpatrick, Andrew D; Yardley, Bruce W D

    2014-08-01

    A novel titanium reaction cell has been constructed for the study of water-rock-CO2 reactions. The reaction cell has been used within a direct-sampling rocking autoclave and offers certain advantages over traditional "flexible gold/titanium cell" approaches. The main advantage is robustness, as flexible cells are prone to rupture on depressurisation during gas-rich experiments. The reaction cell was tested in experiments during an inter-laboratory comparison study, in which mineral kinetic data were determined. The cell performed well during experiments up to 130 °C and 300 bars pressure. The data obtained were similar to those of other laboratories participating in the study, and also to previously published data.

  13. Chemistry Outreach Project to High Schools Using a Mobile Chemistry Laboratory, ChemKits, and Teacher Workshops

    ERIC Educational Resources Information Center

    Long, Gary L.; Bailey, Carol A.; Bunn, Barbara B.; Slebodnick, Carla; Johnson, Michael R.; Derozier, Shad

    2012-01-01

    The Chemistry Outreach Program (ChOP) of Virginia Tech was a university-based outreach program that addressed the needs of high school chemistry classes in underfunded rural and inner-city school districts. The primary features of ChOP were a mobile chemistry laboratory (MCL), a shipping-based outreach program (ChemKits), and teacher workshops.…

  14. Fluid-rock geochemical interaction for modelling calibration in geothermal exploration in Indonesia

    NASA Astrophysics Data System (ADS)

    Deon, Fiorenza; Barnhoorn, Auke; Lievens, Caroline; Ryannugroho, Riskiray; Imaro, Tulus; Bruhn, David; van der Meer, Freek; Hutami, Rizki; Sibarani, Besteba; Sule, Rachmat; Saptadij, Nenny; Hecker, Christoph; Appelt, Oona; Wilke, Franziska

    2017-04-01

    Indonesia with its large, but partially unexplored geothermal potential is one of the most interesting and suitable places in the world to conduct geothermal exploration research. This study focuses on geothermal exploration based on fluid-rock geochemistry/geomechanics and aims to compile an overview on geochemical data-rock properties from important geothermal fields in Indonesia. The research carried out in the field and in the laboratory is performed in the framework of the GEOCAP cooperation (Geothermal Capacity Building program Indonesia- the Netherlands). The application of petrology and geochemistry accounts to a better understanding of areas where operating power plants exist but also helps in the initial exploration stage of green areas. Because of their relevance and geological setting geothermal fields in Java, Sulawesi and the sedimentary basin of central Sumatra have been chosen as focus areas of this study. Operators, universities and governmental agencies will benefit from this approach as it will be applied also to new green-field terrains. By comparing the characteristic of the fluids, the alteration petrology and the rock geochemistry we also aim to contribute to compile an overview of the geochemistry of the important geothermal fields in Indonesia. At the same time the rock petrology and fluid geochemistry will be used as input data to model the reservoir fluid composition along with T-P parameters with the geochemical workbench PHREEQC. The field and laboratory data are mandatory for both the implementation and validation of the model results.

  15. Talking Rocks.

    ERIC Educational Resources Information Center

    Rice, Dale; Corley, Brenda

    1987-01-01

    Discusses some of the ways that rocks can be used to enhance children's creativity and their interest in science. Suggests the creation of a dramatic production involving rocks. Includes basic information on sedimentary, igneous, and metamorphic rocks. (TW)

  16. Constraints on behaviour of a mining‐induced earthquake inferred from laboratory rock mechanics experiments

    USGS Publications Warehouse

    McGarr, Arthur F.; Johnston, Malcolm J.; Boettcher, M.; Heesakkers, V.; Reches, Z.

    2013-01-01

    On December 12, 2004, an earthquake of magnitude 2.2, located in the TauTona Gold Mine at a depth of about 3.65 km in the ancient Pretorius fault zone, was recorded by the in-mine borehole seismic network, yielding an excellent set of ground motion data recorded at hypocentral distances of several km. From these data, the seismic moment tensor, indicating mostly normal faulting with a small implosive component, and the radiated energy were measured; the deviatoric component of the moment tensor was estimated to be M0 = 2.3×1012 N·m and the radiated energy ER = 5.4×108 J. This event caused extensive damage along tunnels within the Pretorius fault zone. What rendered this earthquake of particular interest was the underground investigation of the complex pattern of exposed rupture surfaces combined with laboratory testing of rock samples retrieved from the ancient fault zone (Heesakkers et al.2011a, 2011b). Event 12/12 2004 was the result of fault slip across at least four nonparallel fault surfaces; 25 mm of slip was measured at one location on the rupture segment that is most parallel with a fault plane inferred from the seismic moment tensor, suggesting that this segment accounted for much of the total seismic deformation. By applying a recently developed technique based on biaxial stick-slip friction experiments (McGarr2012, 2013) to the seismic results, together with the 25 mm slip observed underground, we estimated a maximum slip rate of at least 6.6 m/s, which is consistent with the observed damage to tunnels in the rupture zone. Similarly, the stress drop and apparent stress were found to be correspondingly high at 21.9 MPa and 6.6 MPa, respectively. The ambient state of stress, measured at the approximate depth of the earthquake but away from the influence of mining, in conjunction with laboratory measurements of the strength of the fault zone cataclasites, indicates that during rupture of the M 2.2 event, the normal stress acting on the large-slip fault

  17. The MSFC Noble Gas Research Laboratory (MNGRL): A NASA Investigator Facility

    NASA Technical Reports Server (NTRS)

    Cohen, Barbara

    2016-01-01

    Noble-gas isotopes are a well-established technique for providing detailed temperature-time histories of rocks and meteorites. We have established the MSFC Noble Gas Research Laboratory (MNGRL) at Marshall Space Flight Center to serve as a NASA investigator facility in the wake of the closure of the JSC laboratory formerly run by Don Bogard. The MNGRL lab was constructed to be able to measure all the noble gases, particularly Ar-Ar and I-Xe radioactive dating to find the formation age of rocks and meteorites, and Ar/Kr/Ne cosmic-ray exposure ages to understand when the meteorites were launched from their parent planets.

  18. Sequential ChIP Protocol for Profiling Bivalent Epigenetic Modifications (ReChIP).

    PubMed

    Desvoyes, Bénédicte; Sequeira-Mendes, Joana; Vergara, Zaida; Madeira, Sofia; Gutierrez, Crisanto

    2018-01-01

    Identification of chromatin modifications, e.g., histone acetylation and methylation, among others, is widely carried out by using a chromatin immunoprecipitation (ChIP) strategy. The information obtained with these procedures is useful to gain an overall picture of modifications present in all cells of the population under study. It also serves as a basis to figure out the mechanisms of chromatin organization and gene regulation at the population level. However, the ultimate goal is to understand gene regulation at the level of single chromatin fibers. This requires the identification of chromatin modifications that occur at a given genomic location and within the same chromatin fiber. This is achieved by following a sequential ChIP strategy using two antibodies to distinguish different chromatin modifications. Here, we describe a sequential ChIP protocol (Re-ChIP), paying special attention to the controls needed and the required steps to obtain meaningful and reproducible results. The protocol is developed for young Arabidopsis seedlings but could be adapted to other plant materials.

  19. Experimental Estimation Of Energy Damping During Free Rocking Of Unreinforced Masonry Walls. First Results

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sorrentino, Luigi; Masiani, Renato; Benedetti, Stefano

    2008-07-08

    This paper presents an ongoing experimental program on unreinforced masonry walls undergoing free rocking. Aim of the laboratory campaign is the estimation of kinetic energy damping exhibited by walls released with non-zero initial conditions of motion. Such energy damping is necessary for dynamic modelling of unreinforced masonry local mechanisms. After a brief review of the literature on this topic, the main features of the laboratory tests are presented. The program involves the experimental investigation of several parameters: 1) unit material (brick or tuff), 2) wall aspect ratio (ranging between 14.5 and 7.1), 3) restraint condition (two-sided or one-sided rocking), andmore » 4) depth of the contact surface between facade and transverse walls (one-sided rocking only). All walls are single wythe and the mortar is pozzuolanic. The campaign is still in progress. However, it is possible to present the results on most of the mechanical properties of mortar and bricks. Moreover, a few time histories are reported, already indicating the need to correct some of the assumptions frequent in the literature.« less

  20. On the effective stress law for rock-on-rock frictional sliding, and fault slip triggered by means of fluid injection.

    PubMed

    Rutter, Ernest; Hackston, Abigail

    2017-09-28

    Fluid injection into rocks is increasingly used for energy extraction and for fluid wastes disposal, and can trigger/induce small- to medium-scale seismicity. Fluctuations in pore fluid pressure may also be associated with natural seismicity. The energy release in anthropogenically induced seismicity is sensitive to amount and pressure of fluid injected, through the way that seismic moment release is related to slipped area, and is strongly affected by the hydraulic conductance of the faulted rock mass. Bearing in mind the scaling issues that apply, fluid injection-driven fault motion can be studied on laboratory-sized samples. Here, we investigate both stable and unstable induced fault slip on pre-cut planar surfaces in Darley Dale and Pennant sandstones, with or without granular gouge. They display contrasting permeabilities, differing by a factor of 10 5 , but mineralogies are broadly comparable. In permeable Darley Dale sandstone, fluid can access the fault plane through the rock matrix and the effective stress law is followed closely. Pore pressure change shifts the whole Mohr circle laterally. In tight Pennant sandstone, fluid only injects into the fault plane itself; stress state in the rock matrix is unaffected. Sudden access by overpressured fluid to the fault plane via hydrofracture causes seismogenic fault slips.This article is part of the themed issue 'Faulting, friction and weakening: from slow to fast motion'. © 2017 The Authors.

  1. On the effective stress law for rock-on-rock frictional sliding, and fault slip triggered by means of fluid injection

    NASA Astrophysics Data System (ADS)

    Rutter, Ernest; Hackston, Abigail

    2017-08-01

    Fluid injection into rocks is increasingly used for energy extraction and for fluid wastes disposal, and can trigger/induce small- to medium-scale seismicity. Fluctuations in pore fluid pressure may also be associated with natural seismicity. The energy release in anthropogenically induced seismicity is sensitive to amount and pressure of fluid injected, through the way that seismic moment release is related to slipped area, and is strongly affected by the hydraulic conductance of the faulted rock mass. Bearing in mind the scaling issues that apply, fluid injection-driven fault motion can be studied on laboratory-sized samples. Here, we investigate both stable and unstable induced fault slip on pre-cut planar surfaces in Darley Dale and Pennant sandstones, with or without granular gouge. They display contrasting permeabilities, differing by a factor of 105, but mineralogies are broadly comparable. In permeable Darley Dale sandstone, fluid can access the fault plane through the rock matrix and the effective stress law is followed closely. Pore pressure change shifts the whole Mohr circle laterally. In tight Pennant sandstone, fluid only injects into the fault plane itself; stress state in the rock matrix is unaffected. Sudden access by overpressured fluid to the fault plane via hydrofracture causes seismogenic fault slips. This article is part of the themed issue 'Faulting, friction and weakening: from slow to fast motion'.

  2. On the effective stress law for rock-on-rock frictional sliding, and fault slip triggered by means of fluid injection

    PubMed Central

    Hackston, Abigail

    2017-01-01

    Fluid injection into rocks is increasingly used for energy extraction and for fluid wastes disposal, and can trigger/induce small- to medium-scale seismicity. Fluctuations in pore fluid pressure may also be associated with natural seismicity. The energy release in anthropogenically induced seismicity is sensitive to amount and pressure of fluid injected, through the way that seismic moment release is related to slipped area, and is strongly affected by the hydraulic conductance of the faulted rock mass. Bearing in mind the scaling issues that apply, fluid injection-driven fault motion can be studied on laboratory-sized samples. Here, we investigate both stable and unstable induced fault slip on pre-cut planar surfaces in Darley Dale and Pennant sandstones, with or without granular gouge. They display contrasting permeabilities, differing by a factor of 105, but mineralogies are broadly comparable. In permeable Darley Dale sandstone, fluid can access the fault plane through the rock matrix and the effective stress law is followed closely. Pore pressure change shifts the whole Mohr circle laterally. In tight Pennant sandstone, fluid only injects into the fault plane itself; stress state in the rock matrix is unaffected. Sudden access by overpressured fluid to the fault plane via hydrofracture causes seismogenic fault slips. This article is part of the themed issue ‘Faulting, friction and weakening: from slow to fast motion’. PMID:28827423

  3. Rock sample brought to earth from the Apollo 12 lunar landing mission

    NASA Technical Reports Server (NTRS)

    1969-01-01

    Close-up view of Apollo 12 sample 12,062 under observation in the Manned Spacecraft Center's Lunar Receiving Laboratory. This sample, collected during the second Apollo 12 extravehicular activity (EVA-2) of Astronauts Charles Conrad Jr., and Alan L. Bean, is a medium-grained rock with lath-shaped crystals of feldspar and pyroxene It contains vugs-holes-with crystals growing in them (note right side of exposed portion). An idea of the size of the rock can be gained by reference to the gauge on the bottom portion of the number meter.

  4. Fluid evolution during burial and Variscan deformation in the Lower Devonian rocks of the High-Ardenne slate belt (Belgium): sources and causes of high-salinity and C-O-H-N fluids

    NASA Astrophysics Data System (ADS)

    Kenis, I.; Muchez, Ph.; Verhaert, G.; Boyce, A.; Sintubin, M.

    2005-08-01

    Fluid inclusions in quartz veins of the High-Ardenne slate belt have preserved remnants of prograde and retrograde metamorphic fluids. These fluids were examined by petrography, microthermometry and Raman analysis to define the chemical and spatial evolution of the fluids that circulated through the metamorphic area of the High-Ardenne slate belt. The earliest fluid type was a mixed aqueous/gaseous fluid (H2O-NaCl-CO2-(CH4-N2)) occurring in growth zones and as isolated fluid inclusions in both the epizonal and anchizonal part of the metamorphic area. In the central part of the metamorphic area (epizone), in addition to this mixed aqueous/gaseous fluid, primary and isolated fluid inclusions are also filled with a purely gaseous fluid (CO2-N2-CH4). During the Variscan orogeny, the chemical composition of gaseous fluids circulating through the Lower Devonian rocks in the epizonal part of the slate belt, evolved from an earlier CO2-CH4-N2 composition to a later composition enriched in N2. Finally, a late, Variscan aqueous fluid system with a H2O-NaCl composition migrated through the Lower Devonian rocks. This latest type of fluid can be observed in and outside the epizonal metamorphic part of the High-Ardenne slate belt. The chemical composition of the fluids throughout the metamorphic area, shows a direct correlation with the metamorphic grade of the host rock. In general, the proportion of non-polar species (i.e. CO2, CH4, N2) with respect to water and the proportion of non-polar species other than CO2 increase with increasing metamorphic grade within the slate belt. In addition to this spatial evolution of the fluids, the temporal evolution of the gaseous fluids is indicative for a gradual maturation due to metamorphism in the central part of the basin. In addition to the maturity of the metamorphic fluids, the salinity of the aqueous fluids also shows a link with the metamorphic grade of the host-rock. For the earliest and latest fluid inclusions in the anchizonal

  5. A search for interstellar CH3D: Limits to the methane abundance in Orion-KL

    NASA Technical Reports Server (NTRS)

    Womack, Maria; Ziurys, L. M.; Apponi, A. J.

    1995-01-01

    A search has been performed for interstellar CH3D via its J(K) = 1(0) - 0(0) transition at 230 GHz and its J(K) = 2(0) - l(0) and J(K) = 2(1) - 1(1) lines at 465 GHz using the NRAO 12 m and CSO 10 m telescopes towards Orion-KL. This search was done in conjunction with laboratory measurements of all three transitions of CH3D using mm/sub-mm direct absorption spectroscopy. The molecule was not detected down to a 3 sigma level of T(A) less than 0.05 K towards Orion, which suggests an upper limit to the CH3D column density of N less than 6 x 10(exp 18)/sq cm in the hot core region and a fractional abundance (with respect to H2) of less than 6 x 10(exp -6). These measurements suggest that the methane abundance in the Orion hot core is f less than 6 x 10-4, assuming D/H approximately 0.01. Such findings are in agreement with recent hot core chemical models, which suggest CH4/H2 approximately 10(exp -4).

  6. In-plane chemical pressure essential for superconductivity in BiCh2-based (Ch: S, Se) layered structure

    PubMed Central

    Mizuguchi, Yoshikazu; Miura, Akira; Kajitani, Joe; Hiroi, Takafumi; Miura, Osuke; Tadanaga, Kiyoharu; Kumada, Nobuhiro; Magome, Eisuke; Moriyoshi, Chikako; Kuroiwa, Yoshihiro

    2015-01-01

    BiCh2-based compounds (Ch: S, Se) are a new series of layered superconductors, and the mechanisms for the emergence of superconductivity in these materials have not yet been elucidated. In this study, we investigate the relationship between crystal structure and superconducting properties of the BiCh2-based superconductor family, specifically, optimally doped Ce1−xNdxO0.5F0.5BiS2 and LaO0.5F0.5Bi(S1−ySey)2. We use powder synchrotron X-ray diffraction to determine the crystal structures. We show that the structure parameter essential for the emergence of bulk superconductivity in both systems is the in-plane chemical pressure, rather than Bi-Ch bond lengths or in-plane Ch-Bi-Ch bond angle. Furthermore, we show that the superconducting transition temperature for all REO0.5F0.5BiCh2 superconductors can be determined from the in-plane chemical pressure. PMID:26447333

  7. Airworthiness and Flight Characteristics Test (A&FC) of the CH-47D helicopter

    DTIC Science & Technology

    1984-02-01

    Development Specification which were evaluated during this test. The Advanced Flight Control System heading select capability and the pressure refueling...determine compliance with the CH-47D Prime Item Development Specification (PIDS). 2. This Directorate agrees with the report conclusions and...Evaluations (PAE) (refs 1 and 2. app A), climatic laboratory tests (ref 3), and icing tests (ref 4). The US Army Aviation Research and Development

  8. Laboratory investigation of nitrile ices of Titan's stratospheric clouds

    NASA Astrophysics Data System (ADS)

    Nna Mvondo, D.; Anderson, C. M.; McLain, J. L.; Samuelson, R. E.

    2017-09-01

    Titan's mid to lower stratosphere contains complex cloud systems of numerous organic ice particles comprised of both hydrocarbon and nitrile compounds. Most of these stratospheric ice clouds form as a result of vapor condensation formation processes. However, there are additional ice emission features such as dicyanoacetylene (C4N2) and the 220 cm-1 ice emission feature (the "Haystack") that are difficult to explain since there are no observed vapor emission features associated with these ices. In our laboratory, using a high-vacuum chamber coupled to a FTIR spectrometer, we are engaged in a dedicated investigation of Titan's stratospheric ices to interpret and constrain Cassini Composite InfraRed Spectrometer (CIRS) far-IR data. We will present laboratory transmittance spectra obtained for propionitrile (CH3CH2CN), cyanogen (C2N2) and hydrogen cyanide (HCN) ices, as well as various combinations of their mixtures, to better understand the cloud chemistry occurring in Titan's stratosphere.

  9. Art Rocks with Rock Art!

    ERIC Educational Resources Information Center

    Bickett, Marianne

    2011-01-01

    This article discusses rock art which was the very first "art." Rock art, such as the images created on the stone surfaces of the caves of Lascaux and Altimira, is the true origin of the canvas, paintbrush, and painting media. For there, within caverns deep in the earth, the first artists mixed animal fat, urine, and saliva with powdered minerals…

  10. Direct observation of unimolecular decay of CH{sub 3}CH{sub 2}CHOO Criegee intermediates to OH radical products

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Fang, Yi; Liu, Fang; Lester, Marsha I., E-mail: milester@sas.upenn.edu

    2016-07-28

    The unimolecular decay of carbonyl oxide intermediates, known as Criegee intermediates, produced in alkene ozonolysis is a significant source of OH radicals in the troposphere. Here, the rate of appearance of OH radical products is examined directly in the time-domain for a prototypical alkyl-substituted Criegee intermediate, CH{sub 3}CH{sub 2}CHOO, following vibrational activation under collision-free conditions. Complementary statistical Rice–Ramsperger–Kassel–Marcus calculations of the microcanonical unimolecular decay rate for CH{sub 3}CH{sub 2}CHOO are also carried out at energies in the vicinity of the barrier for 1,4 hydrogen atom transfer that leads to OH products. Tunneling through the barrier, derived from high level electronicmore » structure calculations, contributes significantly to the decay rate. Infrared transitions of CH{sub 3}CH{sub 2}CHOO are identified in the CH stretch overtone region, which are detected by ultraviolet laser-induced fluorescence of the resultant OH products. The features observed are attributed to CH vibrational excitations and conformational forms utilizing insights from theory. Both experiment and theory yield unimolecular decay rates for CH{sub 3}CH{sub 2}CHOO of ca. 10{sup 7} s{sup −1}, which are slower than those obtained for syn-CH{sub 3}CHOO or (CH{sub 3}){sub 2}COO reported previously [Fang et al., J. Chem. Phys. 144, 061102 (2016)] at similar energies. Master equation modeling is also utilized to predict the thermal decay rate of CH{sub 3}CH{sub 2}CHOO under atmospheric conditions, giving a rate of 279 s{sup −1} at 298 K.« less

  11. Thermochemistry and kinetics for 2-butanone-1-yl radical (CH2·C(═O)CH2CH3) reactions with O2.

    PubMed

    Sebbar, N; Bozzelli, J W; Bockhorn, H

    2014-01-09

    Thermochemistry of reactants, intermediates, transition state structures, and products along with kinetics on the association of CH2·C(═O)CH2CH3 (2-butanone-1-yl) with O2 and dissociation of the peroxy adduct isomers are studied. Thermochemical properties are determined using ab initio (G3MP2B3 and G3) composite methods along with density functional theory (B3LYP/6-311g(d,p)). Entropy and heat capacity contributions versus temperature are determined from structures, vibration frequencies, and internal rotor potentials. The CH2·C(═O)CH2CH3 radical + O2 association results in a chemically activated peroxy radical with 27 kcal mol(-1) excess of energy. The chemically activated adduct can react to stabilized peroxy or hydroperoxide alkyl radical adducts, further react to lactones plus hydroxyl radical, or form olefinic ketones and a hydroperoxy radical. Kinetic parameters are determined from the G3 composite methods derived thermochemical parameters, and quantum Rice-Ramsperger-Kassel (QRRK) analysis to calculate k(E) with master equation analysis to evaluate falloff in the chemically activated and dissociation reactions. One new, not previously reported, peroxy chemistry reaction is presented. It has a low barrier path and involves a concerted reaction resulting in olefin formation, H2O elimination, and an alkoxy radical.

  12. Carbonate hosted fault rocks: A review of structural and microstructural characteristic with implications for seismicity in the upper crust

    NASA Astrophysics Data System (ADS)

    Delle Piane, Claudio; Clennell, M. Ben; Keller, Joao V. A.; Giwelli, Ausama; Luzin, Vladimir

    2017-10-01

    The structure, frictional properties and permeability of faults within carbonate rocks exhibit a dynamic interplay that controls both seismicity and the exchange of fluid between different crustal levels. Here we review field and experimental studies focused on the characterization of fault zones in carbonate rocks with the aim of identifying the microstructural indicators of rupture nucleation and seismic slip. We highlight results from experimental research linked to observations on exhumed fault zones in carbonate rocks. From the analysis of these accumulated results we identify the meso and microstructural deformation styles in carbonates rocks and link them to the lithology of the protolith and their potential as seismic indicators. Although there has been significant success in the laboratory reproduction of deformation structures observed in the field, the range of slip rates and dynamic friction under which most of the potential seismic indicators is formed in the laboratory urges caution when using them as a diagnostic for seismic slip. We finally outline what we think are key topics for future research that would lead to a more in-depth understanding of the record of seismic slip in carbonate rocks.

  13. Computing energy levels of CH4, CHD3, CH3D, and CH3F with a direct product basis and coordinates based on the methyl subsystem.

    PubMed

    Zhao, Zhiqiang; Chen, Jun; Zhang, Zhaojun; Zhang, Dong H; Wang, Xiao-Gang; Carrington, Tucker; Gatti, Fabien

    2018-02-21

    Quantum mechanical calculations of ro-vibrational energies of CH 4 , CHD 3 , CH 3 D, and CH 3 F were made with two different numerical approaches. Both use polyspherical coordinates. The computed energy levels agree, confirming the accuracy of the methods. In the first approach, for all the molecules, the coordinates are defined using three Radau vectors for the CH 3 subsystem and a Jacobi vector between the remaining atom and the centre of mass of CH 3 . Euler angles specifying the orientation of a frame attached to CH 3 with respect to a frame attached to the Jacobi vector are used as vibrational coordinates. A direct product potential-optimized discrete variable vibrational basis is used to build a Hamiltonian matrix. Ro-vibrational energies are computed using a re-started Arnoldi eigensolver. In the second approach, the coordinates are the spherical coordinates associated with four Radau vectors or three Radau vectors and a Jacobi vector, and the frame is an Eckart frame. Vibrational basis functions are products of contracted stretch and bend functions, and eigenvalues are computed with the Lanczos algorithm. For CH 4 , CHD 3 , and CH 3 D, we report the first J > 0 energy levels computed on the Wang-Carrington potential energy surface [X.-G. Wang and T. Carrington, J. Chem. Phys. 141(15), 154106 (2014)]. For CH 3 F, the potential energy surface of Zhao et al. [J. Chem. Phys. 144, 204302 (2016)] was used. All the results are in good agreement with experimental data.

  14. Computing energy levels of CH4, CHD3, CH3D, and CH3F with a direct product basis and coordinates based on the methyl subsystem

    NASA Astrophysics Data System (ADS)

    Zhao, Zhiqiang; Chen, Jun; Zhang, Zhaojun; Zhang, Dong H.; Wang, Xiao-Gang; Carrington, Tucker; Gatti, Fabien

    2018-02-01

    Quantum mechanical calculations of ro-vibrational energies of CH4, CHD3, CH3D, and CH3F were made with two different numerical approaches. Both use polyspherical coordinates. The computed energy levels agree, confirming the accuracy of the methods. In the first approach, for all the molecules, the coordinates are defined using three Radau vectors for the CH3 subsystem and a Jacobi vector between the remaining atom and the centre of mass of CH3. Euler angles specifying the orientation of a frame attached to CH3 with respect to a frame attached to the Jacobi vector are used as vibrational coordinates. A direct product potential-optimized discrete variable vibrational basis is used to build a Hamiltonian matrix. Ro-vibrational energies are computed using a re-started Arnoldi eigensolver. In the second approach, the coordinates are the spherical coordinates associated with four Radau vectors or three Radau vectors and a Jacobi vector, and the frame is an Eckart frame. Vibrational basis functions are products of contracted stretch and bend functions, and eigenvalues are computed with the Lanczos algorithm. For CH4, CHD3, and CH3D, we report the first J > 0 energy levels computed on the Wang-Carrington potential energy surface [X.-G. Wang and T. Carrington, J. Chem. Phys. 141(15), 154106 (2014)]. For CH3F, the potential energy surface of Zhao et al. [J. Chem. Phys. 144, 204302 (2016)] was used. All the results are in good agreement with experimental data.

  15. Overexpression of ROCK1 and ROCK2 inhibits human laryngeal squamous cell carcinoma

    PubMed Central

    Zhang, Junbo; He, Xue; Ma, Yueying; Liu, Yanli; Shi, Huaiyin; Guo, Weiwei; Liu, Liangfa

    2015-01-01

    Rho-associated coiled-coil containing protein kinase (ROCK) over-expression has been implicated in the progression of many tumor types. The aim of this study was to explore the roles of ROCK1 and ROCK2 in human laryngeal squamous cell carcinoma (LSCC). ROCK1 and ROCK2 expression levels were examined in 50 cases of human LSCC samples by immunohistochemistry. Effects of ROCK1 and ROCK2 on LSCC cell proliferation and motility were investigated in the presence of the ROCK inhibitor Y-27632. The results showed that ROCK1 expression was positively correlated with tumor size and lymph node metastasis (P < 0.05); ROCK2 positively correlated with tumor size (P < 0.05). Inhibition of ROCK1 and ROCK2 by Y-27632 significantly inhibits proliferation, migration, and invasion of LSCC cells. Our data indicate that expression of ROCK1 and ROCK2 are closely associated with tumor growth and lymph node metastasis of LSCC. Thus, these two ROCK isoforms may be useful as molecular makers for LSCC diagnosis and may be useful therapeutic targets as well. PMID:25755711

  16. Integration of NASA/GSFC and USGS Rock Magnetic Databases.

    NASA Astrophysics Data System (ADS)

    Nazarova, K. A.; Glen, J. M.

    2004-05-01

    A global Magnetic Petrology Database (MPDB) was developed and continues to be updated at NASA/Goddard Space Flight Center. The purpose of this database is to provide the geomagnetic community with a comprehensive and user-friendly method of accessing magnetic petrology data via the Internet for a more realistic interpretation of satellite (as well as aeromagnetic and ground) lithospheric magnetic anomalies. The MPDB contains data on rocks from localities around the world (about 19,000 samples) including the Ukranian and Baltic Shields, Kamchatka, Iceland, Urals Mountains, etc. The MPDB is designed, managed and presented on the web as a research oriented database. Several database applications have been specifically developed for data manipulation and analysis of the MPDB. The geophysics unit at the USGS in Menlo Park has over 17,000 rock-property data, largely from sites within the western U.S. This database contains rock-density and rock-magnetic parameters collected for use in gravity and magnetic field modeling, and paleomagnetic studies. Most of these data were taken from surface outcrops and together they span a broad range of rock types. Measurements were made either in-situ at the outcrop, or in the laboratory on hand samples and paleomagnetic cores acquired in the field. The USGS and NASA/GSFC data will be integrated as part of an effort to provide public access to a single, uniformly maintained database. Due to the large number of data and the very large area sampled, the database can yield rock-property statistics on a broad range of rock types; it is thus applicable to study areas beyond the geographic scope of the database. The intent of this effort is to provide incentive for others to further contribute to the database, and a tool with which the geophysical community can entertain studies formerly precluded.

  17. VizieR Online Data Catalog: methoxy radical (CH3O) rotational spectrum (Laas+,

    NASA Astrophysics Data System (ADS)

    Laas, J. C.; Widicus Weaver, S. L.

    2017-08-01

    The methoxy radical (CH3O) has recently been detected interstellar medium and may be an important tracer of methanol-related chemistry in cold sources. Despite its importance, the spectral information needed to guide further astronomical searches is limited. We have therefore studied the low-temperature rotational spectrum in the laboratory within the spectral range of 246-303GHz. We have combined these new measurements with results from a number of literature reports to refine the molecular parameters and provide an updated and improved spectral line catalog. We present here the results of the laboratory studies and the refined analysis for the millimeter and submillimeter spectrum of methoxy. (1 data file).

  18. A laboratory study of supercritical CO2 adsorption on cap rocks in the geological storage conditions

    NASA Astrophysics Data System (ADS)

    Jedli, Hedi; Jbara, Abdessalem; Hedfi, Hachem; Bouzgarrou, Souhail; Slimi, Khalifa

    2017-04-01

    In the present study, various cap rocks have been experimentally reacted in water with supercritical CO2 in geological storage conditions ( P = 8 × 106 Pa and T = 80 °C) for 25 days. To characterize the potential CO2-water-rock interactions, an experimental setup has been built to provide additional information concerning the effects of structure, thermal and surface characteristics changes due to CO2 injection with cap rocks. In addition, CO2 adsorption capacities of different materials (i.e., clay evaporate and sandstone) are measured. These samples were characterized by XRD technique. The BET specific surface area was determined by nitrogen isotherms. In addition, thermal characteristics of untreated adsorbents were analyzed via TGA method and topography surfaces are identified by Scanning Electron Microscope (SEM). Taking into account pressure and temperature, the physical as well as chemical mechanisms of CO2 retention were determined. Isotherm change profiles of samples for relative pressure range indicate clearly that CO2 was adsorbed in different quantities. In accordance with the X-ray diffraction, a crystalline phase was formed due to the carbonic acid attack and precipitation of some carbonate.

  19. Rheological Characteristics of Cement Grout and its Effect on Mechanical Properties of a Rock Fracture

    NASA Astrophysics Data System (ADS)

    Liu, Quansheng; Lei, Guangfeng; Peng, Xingxin; Lu, Chaobo; Wei, Lai

    2018-02-01

    Grouting reinforcement, which has an obvious strengthening effect on fractured rock mass, has been widely used in various fields in geotechnical engineering. The rheological properties of grout will greatly affect its diffusion radius in rock fractures, and the water-cement ratio is an important factor in determining the grouting flow patterns. The relationship between shear stress and shear rate which could reflect the grout rheological properties, the effects of water-cement ratio, and temperature on the rheological properties of grouting was studied in the laboratory. Besides, a new method for producing fractured rock specimens was proposed and solved the problem of producing natural fractured rock specimens. To investigate the influences of grouting on mechanical properties of a rock fracture, the fractured rock specimens made using the new method were reinforced by grouting on the independent designed grouting platform, and then normal and tangential mechanical tests were carried out on fractured rock specimens. The results showed that the mechanical properties of fractured rock mass are significantly improved by grouting, the peak shear strength and residual strength of rock fractures are greatly improved, and the resistance to deformation is enhanced after grouting. Normal forces affect the tangential behavior of the rock fracture, and the tangential stress strength increases with normal forces. The strength and stability of fractured rock mass are increased by grouting reinforcement.

  20. Potential Cement Phases in Sedimentary Rocks Drilled by Curiosity at Gale Crater, Mars

    NASA Technical Reports Server (NTRS)

    Rampe, E. B.; Morris, R. V.; Bish, D. L.; Chipera, S. J.; Ming, D. W.; Blake, D. F.; Vaniman, D. T.; Bristow, T. F.; Cavanagh, P.; Farmer, J. D.; hide

    2015-01-01

    The Mars Science Laboratory rover Curiosity has encountered a variety of sedimentary rocks in Gale crater with different grain sizes, diagenetic features, sedimentary structures, and varying degrees of resistance to erosion. Curiosity has drilled three rocks to date and has analyzed the mineralogy, chemical composition, and textures of the samples with the science payload. The drilled rocks are the Sheepbed mudstone at Yellowknife Bay on the plains of Gale crater (John Klein and Cumberland targets), the Dillinger sandstone at the Kimberley on the plains of Gale crater (Windjana target), and a sedimentary unit in the Pahrump Hills in the lowermost rocks at the base of Mt. Sharp (Confidence Hills target). CheMin is the Xray diffractometer on Curiosity, and its data are used to identify and determine the abundance of mineral phases. Secondary phases can tell us about aqueous alteration processes and, thus, can help to elucidate past aqueous environments. Here, we present the secondary mineralogy of the rocks drilled to date as seen by CheMin and discuss past aqueous environments in Gale crater, the potential cementing agents in each rock, and how amorphous materials may play a role in cementing the sediments.

  1. Laboratory Studies of Organic Compounds With Reflectance Spectroscopy

    NASA Astrophysics Data System (ADS)

    Curchin, J. M.; Clark, R. N.; Hoefen, T. M.

    2007-12-01

    In order to properly interpret reflectance spectra of any solar system surface from the earth to the Oort cloud, laboratory spectra of candidate materials for comparative analysis are needed. Although the common cosmochemical species (H2O, CO2, CO, NH3, and CH4) are well represented in the spectroscopic literature, comparatively little reflectance work has been done on organics from room to cryogenic temperatures at visible to near infrared wavelengths. Reflectance spectra not only enhance weak or unseen transmission features, they are also more analogous to spectra obtained by spacecraft that are imaging such bodies as giant planet moons, kuiper belt objects, centaurs, comets and asteroids, as well as remote sensing of the earth. The USGS Spectroscopy Laboratory is measuring reflectance spectra of organic compounds from room to cryogenic temperatures over the spectral range of 0.35 to 15.5 microns. This region encompasses the fundamental absorptions and many overtones and combinations of C, H, O, and N molecular bonds. Because most organic compounds belong to families whose members have similar structure and composition, individual species identification within a narrow wavelength range may be ambiguous. By measuring spectral reflectance of the pure laboratory samples from the visible through the near and mid-infrared, absorption bands unique to each can be observed, cataloged, and compared to planetary reflectance data. We present here spectra of organic compounds belonging to five families: the alkanes, alkenes, alkynes, aromatics, and cyanides. Common to all of these are the deep C-H stretch fundamental absorptions, which shift shortward from 3.35+ microns in alkanes to 3.25+ microns in aromatics, to 3.2+ microns in alkenes, and down to 3.0+ microns in alkynes. Mid-IR absorptions due to C-H bending deformations at 6.8+ and 7.2+ microns are also identified. In the near infrared these stretching and bending fundamentals yield a diagnostic set of combination

  2. Naval Research Laboratory Arctic Initiatives

    DTIC Science & Technology

    2011-06-01

    Campaign Code 7420 Arctic Modeling Code 7320/7500/7600 In-situ NRL, CRREL NRL boreholes Strategy Remote Sensing Synergism −Collect in-situ...Navy and Marine Corps Corporate Laboratory An array of BMFCs being prepared for deployment. Each BMFC consists of a weighted anode laid flat onto...Gas CH4 E C D CO2 BGHS Free Methane Gas Hydrates HCO3- HCO3- Seismic and geochemical data to predict deep sediment hydrates Estimate spatial

  3. Characterizing Fracturing of Clay-Rich Lower Watrous Rock: From Laboratory Experiments to Nonlocal Damage-Based Simulations

    NASA Astrophysics Data System (ADS)

    Guy, N.; Seyedi, D. M.; Hild, F.

    2018-06-01

    The work presented herein aims at characterizing and modeling fracturing (i.e., initiation and propagation of cracks) in a clay-rich rock. The analysis is based on two experimental campaigns. The first one relies on a probabilistic analysis of crack initiation considering Brazilian and three-point flexural tests. The second one involves digital image correlation to characterize crack propagation. A nonlocal damage model based on stress regularization is used for the simulations. Two thresholds both based on regularized stress fields are considered. They are determined from the experimental campaigns performed on Lower Watrous rock. The results obtained with the proposed approach are favorably compared with the experimental results.

  4. The Geothermic Fatigue Hydraulic Fracturing Experiment in Äspö Hard Rock Laboratory, Sweden: New Insights Into Fracture Process through In-situ AE Monitoring

    NASA Astrophysics Data System (ADS)

    Kwiatek, G.; Plenkers, K.; Zang, A.; Stephansson, O.; Stenberg, L.

    2016-12-01

    The geothermic Fatigue Hydraulic Fracturing (FHF) in situ experiment (Nova project 54-14-1) took place in the Äspö Hard Rock Laboratory/Sweden in a 1.8 Ma old granitic to dioritic rock mass. The experiment aims at optimizing geothermal heat exchange in crystalline rock mass by multistage hydraulic fracturing at 10 m scale. Six fractures are driven by three different water injection schemes (continuous, cyclic, pulse pressurization) inside a 28 m long, horizontal borehole at depth level 410 m. The rock volume subject to hydraulic fracturing and monitored by three different networks with acoustic emission (AE), micro-seismicity and electromagnetic sensors is about 30 m x 30 m x 30 m in size. The 16-channel In-situ AE monitoring network by GMuG monitored the rupture generation and propagation in the frequency range 1000 Hz to 100,000 Hz corresponding to rupture dimensions from cm- to dm-scale. The in-situ AE monitoring system detected and analyzed AE activity in-situ (P- and S-wave picking, localization). The results were used to review the ongoing microfracturing activity in near real-time. The in-situ AE monitoring network successfully recorded and localized 196 seismic events for most, but not all, hydraulic fractures. All AE events detected in-situ occurred during fracturing time periods. The source parameters (fracture sizes, moment magnitudes, static stress drop) of AE events framing injection periods were calculated using the combined spectral fitting/spectra ratio techniques. The AE activity is clustered in space and clearly outline the fractures location, its orientation, and expansion as well as their temporal evolution. The outward migration of AE events away from the borehole is observed. Fractures extend up to 7 m from the injection interval in the horizontal borehole. The fractures orientation and location correlate for most fractures roughly with the results gained by image packer. Clear differences in seismic response between hydraulic fractures in

  5. Rock sample brought to earth from the Apollo 12 lunar landing mission

    NASA Technical Reports Server (NTRS)

    1969-01-01

    Astronaut Charles Conrad Jr., commander of the Apollo 12 lunar landing mission, holds two lunar rocks which were among the samples brought back from the Moon by the Apollo 12 astronauts. The samples are under scientific examination in the Manned Spacecraft Center's Lunar Receiving Laboratory.

  6. Capillary controls on brine percolation in rock salt

    NASA Astrophysics Data System (ADS)

    Hesse, M. A.; Prodanovic, M.; Ghanbarzadeh, S.

    2016-12-01

    The ability the microstructure in rock salt to evolve to minimize the surface energy of the pore-space exerts an important control on brine percolation. The behavior is especially interesting under conditions when brine is wetting the grain boundaries and the pore network percolates at very low porosities, below the transport threshold in typical porous media. We present pore-scale simulations of texturally equilibrated pore spaces in real polycrystalline materials. This allows us to probe the basic physical properties of these materials, such as percolation and trapping thresholds as well as permeability-porosity relationships. Laboratory experiments in NaCl-H2O system are consistent with the computed percolation thresholds. Field data from hydrocarbon exploration wells in rock salt show that fluid commonly invades the lower section of the salt domes. This is consistent with laboratory measurements that show that brine begins to wet the salt grain boundaries with increasing pressure and temperature and theoretical arguments suggesting this would lead to fluid invasion. In several salt domes, however, fluid have percolated to shallower depths, apparently overcoming a substantial percolation threshold. This is likely due to the shear deformation in salt domes, which is not accounted for in theory and experiments.

  7. Rock Games.

    ERIC Educational Resources Information Center

    Topal, Cathy Weisman

    1985-01-01

    Elementary school children are given cards containing specific criteria for doing one or two tasks: sorting or arranging rocks. Sorting tasks involve children in picking out rocks with particular characteristics, such as color or shape. In the arranging tasks children are asked to arrange rocks according to size or value. (RM)

  8. Collecting Rocks.

    ERIC Educational Resources Information Center

    Barker, Rachel M.

    One of a series of general interest publications on science topics, the booklet provides those interested in rock collecting with a nontechnical introduction to the subject. Following a section examining the nature and formation of igneous, sedimentary, and metamorphic rocks, the booklet gives suggestions for starting a rock collection and using…

  9. Characterization of Hydraulic Fractures Growth During the Äspö Hard Rock Laboratory Experiment (Sweden)

    NASA Astrophysics Data System (ADS)

    López-Comino, J. A.; Cesca, S.; Heimann, S.; Grigoli, F.; Milkereit, C.; Dahm, T.; Zang, A.

    2017-11-01

    A crucial issue to characterize hydraulic fractures is the robust, accurate and automated detection and location of acoustic emissions (AE) associated with the fracture nucleation and growth process. Waveform stacking and coherence analysis techniques are here adapted using massive datasets with very high sampling (1 MHz) from a hydraulic fracturing experiment that took place 410 m below surface in the Äspö Hard Rock Laboratory (Sweden). We present the results obtained during the conventional, continuous water injection experiment Hydraulic Fracture 2. The resulting catalogue is composed of more than 4000 AEs. Frequency-magnitude distribution from AE magnitudes (MAE) reveals a high b value of 2.4. The magnitude of completeness is also estimated approximately MAE 1.1, and we observe an interval range of MAE between 0.77 and 2.79. The hydraulic fractures growth is then characterized by mapping the spatiotemporal evolution of AE hypocentres. The AE activity is spatially clustered in a prolate ellipsoid, resembling the main activated fracture volume ( 105 m3), where the lengths of the principal axes ( a = 10 m; b = 5 m; c = 4 m) define its size and its orientation can be estimated for a rupture plane (strike 123°, dip 60°). An asymmetric rupture process regarding to the fracturing borehole is clearly exhibited. AE events migrate upwards covering the depth interval between 404 and 414 m. After completing each injection and reinjection phase, the AE activity decreases and appears located in the same area of the initial fracture phase, suggesting a crack-closing effect.

  10. CH_{4} production in the deep soil as a source of stem CH_{4} emission in Fagus sylvatica}

    NASA Astrophysics Data System (ADS)

    Maier, Martin; Machacova, Katerina; Urban, Otmar; Lang, Friederike

    2017-04-01

    Predicting greenhouse gas (GHG) fluxes on a global scale requires understanding fluxes on the local scale. Understanding GHG processes in soil-plant-atmosphere systems is essential to understand and mitigate GHG fluxes on the local scale. Forests are known to act as carbon sink. Yet, trees at waterlogged sites are known to emit large amounts of CH4, what can offset the positive GHG balance due the CO2 that is sequestered as wood. Generally, upland trees like European beech (Fagus sylvatica L.) are assumed not to emit CH4, and the upland forest soils are regarded as CH4 sinks. Soil-atmosphere fluxes and stem-atmosphere fluxes of CH4 were studied together with soil gas profiles at two upland beech forest sites in Germany and Czech Republic. Soil was a net CH4 sink at both sites. While most trees showed no or low emissions, one beech tree had exorbitant CH4 emissions that were higher than the CH4 sink capacity of the soil. A soil survey showed strong redoximorphic color patterns in the soil adjacent to this tree. Although the soil around the tree was taking up CH4, the soil gas profiles around this tree showed CH4 production at a soil depth >0.3 m. We interpret the coincidence of the production of CH4 in the deep soil below the beech with the large stem emissions as strong hint that there is a transport link between the soil and stem. We think that the root system represents a preferential transport system for CH4 despite the fact that beech roots usually do not have a special gas transport tissue. The observed CH4 stem emissions represent an important CH4 flux in this ecosystem, and, thus, should be considered in future research. Acknowledgement This research was supported by the Czech Academy of Sciences and the German Academic Exchange Service within the project "Methane (CH4) and nitrous oxide (N2O) emissions from Fagus sylvatica trees" (DAAD-15-03), the Czech Science Foundation (17-18112Y), National Programme for Sustainability I (LO1415) and project DFG (MA 5826

  11. Experimental and Computational Study fo CH, CH*, and OH* in an Axisymmetric Laminar Diffusion Flame

    NASA Technical Reports Server (NTRS)

    Walsh, K. T.

    1998-01-01

    In this study, we extend the results of previous combined numerical and experimental investigations of an axisymmetric laminar diffusion flame in which difference Raman spectroscopy, laser-induced fluorescence (LIF), and a multidimensional flame model were used to generate profiles of the temperature and major and minor species. A procedure is outlined by which the number densities of ground-state CH (X(sup 2)II) excited-state CH (A(sup 2)Delta, denoted CH*), and excited-state OH (A(sup 2)Sigma, denoted OH*) are measured and modeled. CH* and OH* number densities are deconvoluted from line-of-sight flame-emission measurements. Ground-state CH is measured using linear LIF. The computations are done with GRI Mech 2.11 as well as an alternate hydrocarbon mechanism. In both cases, additional reactions for the production and consumption of CH* and OH* are added from recent kinetic studies. Collisional quenching and spontaneous emission are responsible for the de-excitation of the excited-state radicals. As with our previous investigations, GRI Mech 2.11 continues to produce very good agreement with the overall flame length observed in the experiments, while significantly under predicting the flame lift-off height. The alternate kinetic scheme is much more accurate in predicting lift-off height but overpredicts the over-all flame length. Ground-state CH profiles predicted with GRI Mech 2.11 are in excellent agreement with the corresponding measurements, regarding both spatial distribution and absolute concentration (measured at 4 ppm) of the CH radical. Calculations of the excited-state species show reasonable agreement with the measurements as far as spatial distribution and overall characteristics are concerned. For OH*, the measured peak mole fraction, 1.3 x 10(exp -8), compared well with computed peaks, while the measured peak level for CH*, 2 x 10(exp -9), was severely underpredicted by both kinetic schemes, indicating that the formation and destruction kinetics

  12. Infrared-Terahertz Double-Resonance Spectroscopy of CH3F and CH3Cl at Atmospheric Pressure

    DTIC Science & Technology

    2012-05-16

    coincidence with the RQ3(6) rovibrational transition in CH3 35Cl [Fig. 4(b)]. At atmospheric pressure, nine more P -, Q-, and R-branch rovibrational...the double-resonance signatures of all IR-THz pump-probe coincidences at atmospheric pressure for 12CH3F and CH3 35Cl 052507-11050-2947/2012/85(5...were calculated using the rotational constants listed in Tables I and II. For CH3F, the standard P - type (J = − 1), Q-type (J = 0), and R-type (J

  13. Apollo rocks, fines and soil cores

    NASA Astrophysics Data System (ADS)

    Allton, J.; Bevill, T.

    Apollo rocks and soils not only established basic lunar properties and ground truth for global remote sensing, they also provided important lessons for planetary protection (Adv. Space Res ., 1998, v. 22, no. 3 pp. 373-382). The six Apollo missions returned 2196 samples weighing 381.7 kg, comprised of rocks, fines, soil cores and 2 gas samples. By examining which samples were allocated for scientific investigations, information was obtained on usefulness of sampling strategy, sampling devices and containers, sample types and diversity, and on size of sample needed by various disciplines. Diversity was increased by using rakes to gather small rocks on the Moon and by removing fragments >1 mm from soils by sieving in the laboratory. Breccias and soil cores are diverse internally. Per unit weight these samples were more often allocated for research. Apollo investigators became adept at wringing information from very small sample sizes. By pushing the analytical limits, the main concern was adequate size for representative sampling. Typical allocations for trace element analyses were 750 mg for rocks, 300 mg for fines and 70 mg for core subsamples. Age-dating and isotope systematics allocations were typically 1 g for rocks and fines, but only 10% of that amount for core depth subsamples. Historically, allocations for organics and microbiology were 4 g (10% for cores). Modern allocations for biomarker detection are 100mg. Other disciplines supported have been cosmogenic nuclides, rock and soil petrology, sedimentary volatiles, reflectance, magnetics, and biohazard studies . Highly applicable to future sample return missions was the Apollo experience with organic contamination, estimated to be from 1 to 5 ng/g sample for Apollo 11 (Simonheit &Flory, 1970; Apollo 11, 12 &13 Organic contamination Monitoring History, U.C. Berkeley; Burlingame et al., 1970, Apollo 11 LSC , pp. 1779-1792). Eleven sources of contaminants, of which 7 are applicable to robotic missions, were

  14. Rock flows

    NASA Technical Reports Server (NTRS)

    Matveyev, S. N.

    1986-01-01

    Rock flows are defined as forms of spontaneous mass movements, commonly found in mountainous countries, which have been studied very little. The article considers formations known as rock rivers, rock flows, boulder flows, boulder stria, gravel flows, rock seas, and rubble seas. It describes their genesis as seen from their morphological characteristics and presents a classification of these forms. This classification is based on the difference in the genesis of the rubbly matter and characterizes these forms of mass movement according to their source, drainage, and deposit areas.

  15. Micromechanical Modeling of Anisotropic Damage-Induced Permeability Variation in Crystalline Rocks

    NASA Astrophysics Data System (ADS)

    Chen, Yifeng; Hu, Shaohua; Zhou, Chuangbing; Jing, Lanru

    2014-09-01

    This paper presents a study on the initiation and progress of anisotropic damage and its impact on the permeability variation of crystalline rocks of low porosity. This work was based on an existing micromechanical model considering the frictional sliding and dilatancy behaviors of microcracks and the recovery of degraded stiffness when the microcracks are closed. By virtue of an analytical ellipsoidal inclusion solution, lower bound estimates were formulated through a rigorous homogenization procedure for the damage-induced effective permeability of the microcracks-matrix system, and their predictive limitations were discussed with superconducting penny-shaped microcracks, in which the greatest lower bounds were obtained for each homogenization scheme. On this basis, an empirical upper bound estimation model was suggested to account for the influences of anisotropic damage growth, connectivity, frictional sliding, dilatancy, and normal stiffness recovery of closed microcracks, as well as tensile stress-induced microcrack opening on the permeability variation, with a small number of material parameters. The developed model was calibrated and validated by a series of existing laboratory triaxial compression tests with permeability measurements on crystalline rocks, and applied for characterizing the excavation-induced damage zone and permeability variation in the surrounding granitic rock of the TSX tunnel at the Atomic Energy of Canada Limited's (AECL) Underground Research Laboratory (URL) in Canada, with an acceptable agreement between the predicted and measured data.

  16. A Measurement of the Rotational Spectrum of the CH Radical in the Far-Infrared

    NASA Astrophysics Data System (ADS)

    Davidson, Steven A.; Evenson, Kenneth M.; Brown, John M.

    2001-01-01

    Rotational and fine-structure transitions between the lower rotational levels of the CH radical in its X2Π state have been observed in absorption in the laboratory with a tunable far-infrared (TuFIR) spectrometer. The molecules were generated in an electric discharge through a mixture of methane and carbon monoxide in helium. The experimental line widths were limited by Doppler broadening and the measurements have a 1 σ experimental uncertainty of 100 kHz. The frequencies have been used together with all previous measurements of CH in the v=0 level of the X2Π electronic state to determine its molecular parameters and to predict an accurate set of rotational transition frequencies. ID="FN1">1We wish to dedicate this paper to our good friend and colleague, Harry Radford, who died on 2000 May 5. His name will live on in association with many groundbreaking pieces of work on the spectroscopy of small molecules, not least with the first detection of the far-infrared spectrum of the CH radical in 1970 March.

  17. Seed dormancy and persistent sediment seed banks of ephemeral freshwater rock pools in the Australian monsoon tropics

    PubMed Central

    Cross, Adam T.; Turner, Shane R.; Renton, Michael; Baskin, Jerry M.; Dixon, Kingsley W.; Merritt, David J.

    2015-01-01

    Background and Aims Rock pools are small, geologically stable freshwater ecosystems that are both hydrologically and biologically isolated. They harbour high levels of plant endemism and experience environmental unpredictability driven by the presence of water over variable temporal scales. This study examined the hypothesis that the sediment seed bank in monsoon tropical freshwater rock pools would persist through one or more periods of desiccation, with seed dormancy regulating germination timing in response to rock pool inundation and drying events. Methods Seeds were collected from seven dominant rock pool species, and germination biology and seed dormancy were assessed under laboratory conditions in response to light, temperature and germination stimulators (gibberellic acid, karrikinolide and ethylene). Field surveys of seedling emergence from freshwater rock pools in the Kimberley region of Western Australia were undertaken, and sediment samples were collected from 41 vegetated rock pools. Seedling emergence and seed bank persistence in response to multiple wetting and drying cycles were determined. Key Results The sediment seed bank of individual rock pools was large (13 824 ± 307 to 218 320 ± 42 412 seeds m−2 for the five species investigated) and spatially variable. Seedling density for these same species in the field ranged from 13 696 to 87 232 seedlings m−2. Seeds of rock pool taxa were physiologically dormant, with germination promoted by after-ripening and exposure to ethylene or karrikinolide. Patterns of seedling emergence varied between species and were finely tuned to seasonal temperature and moisture conditions, with the proportions of emergent seedlings differing between species through multiple inundation events. A viable seed bank persisted after ten consecutive laboratory inundation events, and seeds retained viability in dry sediments for at least 3 years. Conclusions The persistent seed bank in freshwater rock pools is likely to

  18. Rock Finding

    ERIC Educational Resources Information Center

    Rommel-Esham, Katie; Constable, Susan D.

    2006-01-01

    In this article, the authors discuss a literature-based activity that helps students discover the importance of making detailed observations. In an inspiring children's classic book, "Everybody Needs a Rock" by Byrd Baylor (1974), the author invites readers to go "rock finding," laying out 10 rules for finding a "perfect" rock. In this way, the…

  19. Rock Art

    ERIC Educational Resources Information Center

    Henn, Cynthia A.

    2004-01-01

    There are many interpretations for the symbols that are seen in rock art, but no decoding key has ever been discovered. This article describes one classroom's experiences with a lesson on rock art--making their rock art and developing their own personal symbols. This lesson allowed for creativity, while giving an opportunity for integration…

  20. An Aquatic Journey toward Aeolis Mons (Mount Sharp): Sedimentary Rock Evidence observed by Mars Science Laboratory

    NASA Astrophysics Data System (ADS)

    Gupta, Sanjeev; Edgar, Lauren; Williams, Rebecca; Rubin, David; Yingst, Aileen; Lewis, Kevin; Kocurek, Gary; Anderson, Ryan; Dromart, Gilles; Edgett, Ken; Hardgrove, Craig; Kah, Linda; Mangold, Nicolas; Milliken, Ralph; Minitti, Michelle; Palucis, Marisa; Rice, Melissa; Stack, Katie; Sumner, Dawn; Williford, Ken

    2014-05-01

    Since leaving Yellowknife Bay (summer 2013), Mars Science Laboratory Curiosity has investigated a number of key outcrops as it traverses along the Rapid Transit Route toward the entry point to begin its investigations of the extensive rock outcrops at the base of Mount Sharp. Rover observations are characterizing the variability of lithologies and sedimentary facies along the traverse and establishing stratigraphic relationships with the aim of reconstructing depositional processes and palaeoenvironments. Here, we report on sedimentological and stratigraphic observations based on images from the Mastcam and MAHLI instruments at Shaler and the Darwin waypoint. The informally named Shaler outcrop, which forms part of the Glenelg member of the Yellowknife Bay formation [1] is remarkable for the preservation of a rich suite of sedimentary structures and architecture, and was investigated on sols 120-121 and 309-324. The outcrop forms a pebbly sandstone body that is ~0.7 m thick and extends for up to 20 m. Shaler is largely characterized by pebbly sandstone facies showing well-developed decimeter-scale trough cross-stratification. Bedding geometries indicate sub-critical angles of climb, resulting in preservation of only the lee slope deposits. The grain size, and the presence and scale of cross-stratification imply sediment transport and deposition by unidirectional currents in a fluvial sedimentary environment. Curiosity investigated the informally named Darwin waypoint between sols 390 and 401, making detailed Mastcam and MAHLI observations at two separate locations. The Darwin outcrop comprises light-toned sandstone beds separated by darker pebbly sandstones. MAHLI observations permit differentiation of distinct sedimentary facies. The Altar Mountain facies is a poorly sorted pebbly sandstone that is rich in fine pebbles. Pebbles are sub-angular to sub-rounded in shape and show no preferred orientation or fabric. Pebbles and sand grains show clast-to-clast contacts

  1. ChIP-PIT: Enhancing the Analysis of ChIP-Seq Data Using Convex-Relaxed Pair-Wise Interaction Tensor Decomposition.

    PubMed

    Zhu, Lin; Guo, Wei-Li; Deng, Su-Ping; Huang, De-Shuang

    2016-01-01

    In recent years, thanks to the efforts of individual scientists and research consortiums, a huge amount of chromatin immunoprecipitation followed by high-throughput sequencing (ChIP-seq) experimental data have been accumulated. Instead of investigating them independently, several recent studies have convincingly demonstrated that a wealth of scientific insights can be gained by integrative analysis of these ChIP-seq data. However, when used for the purpose of integrative analysis, a serious drawback of current ChIP-seq technique is that it is still expensive and time-consuming to generate ChIP-seq datasets of high standard. Most researchers are therefore unable to obtain complete ChIP-seq data for several TFs in a wide variety of cell lines, which considerably limits the understanding of transcriptional regulation pattern. In this paper, we propose a novel method called ChIP-PIT to overcome the aforementioned limitation. In ChIP-PIT, ChIP-seq data corresponding to a diverse collection of cell types, TFs and genes are fused together using the three-mode pair-wise interaction tensor (PIT) model, and the prediction of unperformed ChIP-seq experimental results is formulated as a tensor completion problem. Computationally, we propose efficient first-order method based on extensions of coordinate descent method to learn the optimal solution of ChIP-PIT, which makes it particularly suitable for the analysis of massive scale ChIP-seq data. Experimental evaluation the ENCODE data illustrate the usefulness of the proposed model.

  2. Evolution of the Earth and Origin of Life: The Role of Gas/Fluid Interactions with Rocks

    NASA Technical Reports Server (NTRS)

    Freund, Friedemann

    2001-01-01

    The work under the Cooperative Agreement will be centered on questions of the evolution of Life on the early Earth and possibly on Mars. It is still hotly debated whether the essential organic molecules were delivered to the early Earth from space (by comets, meteorites or interplanetary dust particles) or were generated in situ on Earth. Prior work that has shown that the matrix of igneous minerals is a medium in which progenitors of organic molecules assemble from H2O, C02 and N2 incorporated as minority "impurities" in minerals of igneous rocks during crystallization from H2O/CO2/N2-laden magmas. The underlying processes involve a redox. conversion whereby C, H, and N become chemically reduced, while 0 becomes oxidized to the peroxy state. During Year 02 the work will be divided into three tasks. Task 1: After carboxylic (fatty) acids and N-bearing compounds have been identified, other extractable organic molecules including lipids, oily substances and amino acids will be studied. Dedicated lipid analysis will be combined with gas chromatographic-mass spectroscopic (GCMS) analysis of organic compounds extracted from minerals and rocks. Task 2: Using infrared (IR) spectroscopy, C-H entities that are indicators for the organic progenitors in mineral matrices will be studied. A preliminary heating experiment with MgO single crystals has shown that the C-H entities can be pyrolyzed, causing the IR bands to disappear, but at room temperature the IR bands reappear in a matter of days to weeks. This work will be expanded, both by studying synthetic MgO crystals and olivine crystals from the Earth's upper mantle. The C-H bands will be compared to the published "organic" IR feature of dust in the interstellar medium (ISM) and interplanetary dust particles (IDP). Task 3: A paradox marks the evolution of early Life: Oxygen is highly toxic to primitive life, yet early organisms "learned" to detoxify reactive oxygen species, to utilize oxygen, and even produce it. Why would

  3. NETL Extreme Drilling Laboratory Studies High Pressure High Temperature Drilling Phenomena

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lyons, K.D.; Honeygan, S.; Moroz, T.H.

    2008-12-01

    The U.S. Department of Energy's National Energy Technology Laboratory (NETL) established the Extreme Drilling Laboratory to engineer effective and efficient drilling technologies viable at depths greater than 20,000 ft. This paper details the challenges of ultradeep drilling, documents reports of decreased drilling rates as a result of increasing fluid pressure and temperature, and describes NETL's research and development activities. NETL is invested in laboratory-scale physical simulation. Its physical simulator will have capability of circulating drilling fluids at 30,000 psi and 480°F around a single drill cutter. This simulator is not yet operational; therefore, the results will be limited to themore » identification of leading hypotheses of drilling phenomena and NETL's test plans to validate or refute such theories. Of particular interest to the Extreme Drilling Laboratory's studies are the combinatorial effects of drilling fluid pressure, drilling fluid properties, rock properties, pore pressure, and drilling parameters, such as cutter rotational speed, weight on bit, and hydraulics associated with drilling fluid introduction to the rock-cutter interface. A detailed discussion of how each variable is controlled in a laboratory setting will be part of the conference paper and presentation.« less

  4. The photolysis of CH3ONO

    NASA Technical Reports Server (NTRS)

    Wiebe, H. A.; Heicklen, J.

    1972-01-01

    The photolysis of CH3ONO, alone and in the presence of NO, NO-N2 mixtures, and NO-CO mixtures was studied between 25 and 150 C. The major products are CH2O, N2O, and H2O. The quantum yields of N2O were measured. The N2O yield is large at low pressures but approaches a high-pressure limiting value of 0.055 at all temperatures as the excited CH3O produced in the primary step is stabilized by collision. In the presence of excess CO, and N2O yield drops, and CO2 is produced (though not in sufficient amounts to account for the drop in N2O). When pure CH2ONO is photolyzed, CO is produced and NO accumulates in the system. Both products are formed in related processes and result from CH3O attack on CH2O.

  5. Improving Site Characterization for Rock Dredging using a Drilling Parameter Recorder and the Point Load Test

    DTIC Science & Technology

    1994-09-01

    materials. Also, available data from drilling rates in the mining and tunneling industries (Howarth and Rowlands 1987, Somerton 1959) indicate a...selected uniform natural rock materials and several man -made rock simulants were used to obtain drilling parameter records for materials of known...Dredging Seminar, Atlantic City, NJ, May 1993. Western Dredging Association (WEDA) and Texas A&M University. Somerton , W. H. (1959). "A laboratory study of

  6. Assigning the low lying vibronic states of CH3O and CD3O

    NASA Astrophysics Data System (ADS)

    Johnson, Britta A.; Sibert, Edwin L.

    2017-05-01

    The assignment of lines in vibrational spectra in strongly mixing systems is considered. Several low lying vibrational states of the ground electronic X˜ 2E state of the CH3O and CD3O radicals are assigned. Jahn-Teller, spin-orbit, and Fermi couplings mix the normal mode states. The mixing complicates the assignment of the infrared spectra using a zero-order normal mode representation. Alternative zero-order representations, which include specific Jahn-Teller couplings, are explored. These representations allow for definitive assignments. In many instances it is possible to plot the wavefunctions on which the assignments are based. The plots, which are shown in the adiabatic representation, allow one to visualize the effects of various higher order couplings. The plots also enable one to visualize the conical seam and its effect on the wavefunctions. The first and the second order Jahn-Teller couplings in the rocking motion dominate the spectral features in CH3O, while first order and modulated first order couplings dominate the spectral features in CD3O. The methods described here are general and can be applied to other Jahn-Teller systems.

  7. Detection and cultivation of indigenous microorganisms in Mesozoic claystone core samples from the Opalinus Clay Formation (Mont Terri Rock Laboratory)

    NASA Astrophysics Data System (ADS)

    Mauclaire, L.; McKenzie, J. A.; Schwyn, B.; Bossart, P.

    Although microorganisms have been isolated from various deep-subsurface environments, the persistence of microbial activity in claystones buried to great depths and on geological time scales has been poorly studied. The presence of in-situ microbial life in the Opalinus Clay Formation (Mesozoic claystone, 170 million years old) at the Mont Terri Rock Laboratory, Canton Jura, Switzerland was investigated. Opalinus Clay is a host rock candidate for a radioactive waste repository. Particle tracer tests demonstrated the uncontaminated nature of the cored samples, showing their suitability for microbiological investigations. To determine whether microorganisms are a consistent and characteristic component of the Opalinus Clay Formation, two approaches were used: (i) the cultivation of indigenous micoorganisms focusing mainly on the cultivation of sulfate-reducing bacteria, and (ii) the direct detection of molecular biomarkers of bacteria. The goal of the first set of experiments was to assess the presence of cultivable microorganisms within the Opalinus Clay Formation. After few months of incubation, the number of cell ranged from 0.1 to 2 × 10 3 cells ml -1 media. The microorganisms were actively growing as confirmed by the observation of dividing cells, and detection of traces of sulfide. To avoid cultivation bias, quantification of molecular biomarkers (phospholipid fatty acids) was used to assess the presence of autochthonous microorganisms. These molecules are good indicators of the presence of living cells. The Opalinus Clay contained on average 64 ng of PLFA g -1 dry claystone. The detected microbial community comprises mainly Gram-negative anaerobic bacteria as indicated by the ratio of iso/anteiso phospholipids (about 2) and the detection of large amount of β-hydroxy substituted fatty acids. The PLFA composition reveals the presence of specific functional groups of microorganisms in particular sulfate-reducing bacteria ( Desulfovibrio, Desulfobulbus, and

  8. Changes in crack shape and saturation during water penetration into stressed rock

    NASA Astrophysics Data System (ADS)

    Masuda, K.; Nishizawa, O.

    2012-12-01

    Open cracks and cavities in rocks play important roles in fluid transport. Water penetration induced microcrack activities and caused the failure of rocks. Fluids in cracks affect earthquake generation mechanism through physical and physicochemical effects. Methods of characterizing crack shape and water saturation of rocks underground are needed for many scientific and industrial applications. It would be desirable to estimate the status of cracks using readily observable data such as elastic-wave velocities. We demonstrate a laboratory method for estimating crack status inside a cylindrical rock sample based on least-squares fitting of a cracked solid model to measured P- and S-wave velocities, and porosity derived from strain data. We used a cylinder (50 mm in diameter and 100 mm in length) of medium-grained granite. We applied a differential stress of 370 MPa, which corresponds to about 70% of fracture strength, to the rock sample under 30 MPa confining pressure and held it constant throughout the experiment. When the primary creep stage and acoustic emission (AE) caused by the initial loading had ceased, we injected distilled water into the bottom end of the sample at a constant pressure of 25 MPa until macroscopic fracture occurred. During water migration, we measured P waves and S waves (Sv and Sh), in five directions parallel to the top and bottom surfaces of the sample. We also measured strains of the sample surface and monitored AE. We created X-ray computer tomography (CT) images of the rock sample after the experiment in order to recognize the location and shape of fractured surfaces. We observed the different patterns of velocity changes in the upper and lower portions of the rock sample. Changes in P-wave velocities can be interpreted based on the crack density. S-waves showed the splitting with Vsv being faster than Vsh, corresponding to the second kind of anisotropy. We estimated two crack characteristics, crack shape and the degree of water

  9. Federal Laboratory Consortium Recognizes Unituxin Collaborators with Excellence in Technology Transfer Awards | Poster

    Cancer.gov

    The Federal Laboratory Consortium (FLC) presented an Excellence in Technology Transfer award to the group that collaborated to bring Unituxin (dinutuximab, also known as ch14.18), an immunotherapy for neuroblastoma, to licensure.

  10. Possible Sources for Methane and C2-C5 Organics in the Plume of Enceladus

    NASA Technical Reports Server (NTRS)

    McKay, Chris; Khare, Bishun N.; Amin, Ranjamin; Klasson, Martin; Kral, Timothy A.

    2012-01-01

    In this paper we consider six possible sources of CH4 and other low-mass (C2 - C5) organics in the plume of Enceladus: initial endowments of cometary organics or Titan- like tholin, in situ production by Fisher-Tropsch type reactions, water-rock reactions, or microbiology, and thermogenesis from heavier organics already present. We report on new laboratory results C2 hydrocarbons released on thermogenesis of laboratory tholin and Fisher-Tropsch type synthesis. Tholin heating produced ratios of CH4/C2H4 and CH4/C2H6 of about 2 for temperatures up to 450 C and about 6 for a temperature of 650 C. Low pressure Fisher-Tropsch type experiments produced CH4/C2H4 of approx 1.5, similar to previous results. No C2H2 was produced by either process. Tests of gas production by four strains of methanogens confirmed the absence of any detectable production of non-methane hydrocarbons. Cometary endowment, Fisher-Tropsch type synthesis, and Titan-like tholin incorporation could be primary inputs of organics and subsequent thermal processing of any of these all are possible sources of low mass organics in the plume. Biological production and water-rock reactions are an alternative source of CH4. Neither water-- ]rock reactions or thermal processing of biomass could be a source C2 . C5 organics due to the low interior pressures. The confirmed detection of CO and C2H2 in the plume of Enceladus would provide an important constraint on sources as we have identified no process . other than the initial volatile component of cometary organics which can supply these gases. Precise determination of the relative concentrations of C1 - C5 hydrocarbons may provide additional constraints on sources but a detailed isotopic analysis of C and H in these organics and a search for amino acids constitute the next important steps in resolving the sources of the organics in Enceladus' plume.

  11. Noble Gas Analysis for Mars Robotic Missions: Evaluating K-Ar Age Dating for Mars Rock Analogs and Martian Shergottites

    NASA Technical Reports Server (NTRS)

    Park, J.; Ming, D. W.; Garrison, D. H.; Jones, J. H.; Bogard, D. D.; Nagao, K.

    2009-01-01

    The purpose of this noble gas investigation was to evaluate the possibility of measuring noble gases in martian rocks and air by future robotic missions such as the Mars Science Laboratory (MSL). The MSL mission has, as part of its payload, the Sample Analysis at Mars (SAM) instrument, which consists of a pyrolysis oven integrated with a GCMS. The MSL SAM instrument has the capability to measure noble gas compositions of martian rocks and atmosphere. Here we suggest the possibility of K-Ar age dating based on noble gas release of martian rocks by conducting laboratory simulation experiments on terrestrial basalts and martian meteorites. We provide requirements for the SAM instrument to obtain adequate noble gas abundances and compositions within the current SAM instrumental operating conditions, especially, a power limit that prevents heating the furnace above approx.1100 C. In addition, Martian meteorite analyses from NASA-JSC will be used as ground truth to evaluate the feasibility of robotic experiments to constrain the ages of martian surface rocks.

  12. Spatial distribution of CH3 and CH2 radicals in a methane rf discharge

    NASA Astrophysics Data System (ADS)

    Sugai, H.; Kojima, H.; Ishida, A.; Toyoda, H.

    1990-06-01

    Spatial distributions of neutral radicals CH3 and CH2 in a capacitively coupled rf glow discharge of methane were measured by threshold ionization mass spectrometry. A strong asymmetry of the density profile was found for the CH2 radical in the high-pressure (˜100 mTorr) discharge. In addition, comprehensive measurements of electron energy distribution, ionic composition, and radical sticking coefficient were made to use as inputs to theoretical modeling of radicals in the methane plasma. The model predictions agree substantially with the measured radical distributions.

  13. Chemical reaction and dust formation studies in laboratory hydrocarbon plasmas.

    NASA Astrophysics Data System (ADS)

    Hippler, Rainer; Majumdar, Abhijit; Thejaswini, H. C.

    Plasma chemical reaction studies with relevance to, e.g., Titan's atmosphere have been per-formed in various laboratory plasmas [1,2]. Chemical reactions in a dielectric barrier discharge at medium pressure of 250-300 mbar have been studied in CH4 /N2 and CH4 /Ar gas mixtures by means of mass spectrometry. The main reaction scheme is production of H2 by fragmenta-tion of CH4 , but also production of larger hydrocarbons like Cn Hm with n up to 10 including formation of different functional CN groups is observed. [1] A. Majumdar and R. Hippler, Development of dielectric barrier discharge plasma processing apparatus for mass spectrometry and thin film deposition, Rev. Sci. Instrum. 78, 075103 (2007) [2] H.T. Do, G. Thieme, M. Frühlich, H. Kersten, and R. Hippler, Ion Molecule and Dust Particle Formation in Ar/CH4 , Ar/C2 H2 and Ar/C3 H6 Radio-frequency Plasmas, Contrib. Plasma Phys. 45, No. 5-6, 378-384 (2005)

  14. Science Rocks!

    ERIC Educational Resources Information Center

    Prestwich, Dorothy; Sumrall, Joseph; Chessin, Debby A.

    2010-01-01

    It all began one Monday morning. Raymond could not wait to come to large group. In his hand, he held a chunk of white granite he had found. "Look at my beautiful rock!" he cried. The rock was passed around and examined by each student. "I wonder how rocks are made?" wondered one student. "Where do they come from?"…

  15. ChemCam for Mars Science Laboratory rover, undergoing pre-flight testing

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    None

    2011-10-20

    Los Alamos National Laboratory and partners developed a laser instrument, ChemCam, that will ride on the elevated mast of the Mars Science Laboratory rover Curiosity. The system allows Curiosity to "zap" rocks from a distance, reading their chemical composition through spectroscopic analysis. In this video, laboratory shaker-table testing of the instrument ensures that all of its components are solidly attached and resistant to damage from the rigors of launch, travel and landing.

  16. ChemCam for Mars Science Laboratory rover, undergoing pre-flight testing

    ScienceCinema

    None

    2018-06-06

    Los Alamos National Laboratory and partners developed a laser instrument, ChemCam, that will ride on the elevated mast of the Mars Science Laboratory rover Curiosity. The system allows Curiosity to "zap" rocks from a distance, reading their chemical composition through spectroscopic analysis. In this video, laboratory shaker-table testing of the instrument ensures that all of its components are solidly attached and resistant to damage from the rigors of launch, travel and landing.

  17. New and improved CH implosions at the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Hinkel, D. E.; Doeppner, T.; Kritcher, A. L.; Ralph, J. E.; Jarrott, L. C.; Albert, F.; Benedetti, L. R.; Field, J. E.; Goyon, C. S.; Hohenberger, M.; Izumi, N.; Milovich, J. L.; Bachmann, B.; Casey, D. T.; Yeamans, C. B.; Callahan, D. A.; Hurricane, O. A.

    2017-10-01

    Improvements to the hohlraum for CH implosions have resulted in near-record hot spot pressures, 225 Gbar. Implosion symmetry and laser energy coupling are improved by using a hohlraum that, compared to the previous high gas-fill hohlraum, is longer, larger, at lower gas fill density, and is fielded at zero wavelength separation to minimize cross-beam energy transfer. With a capsule at 90% of its original size in this hohlraum, implosion symmetry changes from oblate to prolate, at 33% cone fraction. Simulations highlight improved inner beam propagation as the cause of this symmetry change. These implosions have produced the highest yield for CH ablators at modest power and energy, i.e., 360 TW and 1.4 MJ. Upcoming experiments focus on continued improvement in shape as well as an increase in implosion velocity. Further, results and future plans on an increase in capsule size to improve margin will also be presented. Work performed under the auspices of the U.S. D.O.E. by Lawrence Livermore National Laboratory under Contract No. DE-AC52-07NA27344.

  18. Coseismic landslides reveal near-surface rock strength in a high-relief tectonically active setting

    USGS Publications Warehouse

    Gallen, Sean F.; Clark, Marin K.; Godt, Jonathan W.

    2014-01-01

    We present quantitative estimates of near-surface rock strength relevant to landscape evolution and landslide hazard assessment for 15 geologic map units of the Longmen Shan, China. Strength estimates are derived from a novel method that inverts earthquake peak ground acceleration models and coseismic landslide inventories to obtain material proper- ties and landslide thickness. Aggregate rock strength is determined by prescribing a friction angle of 30° and solving for effective cohesion. Effective cohesion ranges are from 70 kPa to 107 kPa for 15 geologic map units, and are approximately an order of magnitude less than typical laboratory measurements, probably because laboratory tests on hand-sized specimens do not incorporate the effects of heterogeneity and fracturing that likely control near-surface strength at the hillslope scale. We find that strength among the geologic map units studied varies by less than a factor of two. However, increased weakening of units with proximity to the range front, where precipitation and active fault density are the greatest, suggests that cli- matic and tectonic factors overwhelm lithologic differences in rock strength in this high-relief tectonically active setting.

  19. Heterogeneities of mechanical properties in potential geothermal reservoir rocks of the North German Basin

    NASA Astrophysics Data System (ADS)

    Reyer, D.; Philipp, S. L.

    2012-04-01

    Heterogeneous rock properties in terms of layering and complex infrastructure of fault zones are typical phenomena in sedimentary basins such as the North German Basin. To be able to model reservoir stimulation in layered stratifications and to better adapt the drilling strategy to the rock mechanical conditions it is important to have knowledge about the effects of heterogeneous rock properties on fracture propagation and fault zone infrastructure for typical sedimentary reservoir rocks in the North German Basin. Therefore we aim at quantifying these properties by performing structural geological field studies in outcrop analogues combined with laboratory analyses. The field studies in Rotliegend sandstones (Lower Permian), the sandstones of the Middle Bunter (Lower Triassic) and the sandstones of the Upper Keuper (Upper Triassic) focus on 1) host rock fracture systems and 2) fault zone infrastructure. We analyse quantitatively the dimension, geometry, persistence and connectivity of fracture systems separately for host rocks and fault damage zones. The results show that in rocks with distinctive layering (sandstones and shales) natural fractures are often restricted to individual layers, that is, they are stratabound. The probability of fracture arrest seems to depend on the stiffness contrast between the two layers and on the thickness of the softer layer. The field studies are complemented by systematic sampling to obtain mechanical property variations caused by the layering. For the samples we measure the parameters Young's modulus, compressive and tensile strengths, elastic strain energy, density and porosity. The results show that the mechanical properties vary considerably and many samples are clearly anisotropic. That is, samples taken perpendicular to layering commonly have higher strengths but lower stiffnesses than those taken parallel to layering. We combine the results of laboratory analyses and field measurements to specify the mechanical

  20. Compositions of Spherules and Rock Surfaces at Meridiani

    NASA Technical Reports Server (NTRS)

    Mittlefehldt, David W.; Jolliff, B. L.; Clark, B. C.; Gellert, R.

    2007-01-01

    The Alpha Particle X-ray Spectrometers (APXS) on the Mars Exploration Rovers (MER) have proven extremely valuable for analyzing rocks and soils on the surface of Mars. The precision of their compositional measurements has been shown to be phenomenal through analyses of the compositionally very uniform Meridiani soils. Through combined use of the rock abrasion tool (RAT) and the analytical instruments on the in-situ deployment device (IDD), analyses of the interiors of fine-grained and texturally uniform rocks with surfaces ground flat have been made under conditions that are nearly ideal for this mode of analysis. The APXS has also been used frequently to analyze materials whose characteristics, surface morphologies, and sample-detector geometries are less than ideal, but the analyses of which are nonetheless very useful for understanding the makeup of the target materials. Such targets include undisturbed rocks with irregular and sometimes coated surfaces and mixed targets such as soils that include fine-grained components as well as coarse grains and pieces of rocks. Such target materials include the well known hematite-rich concretions, referred to as blueberries because of their multispectral color, size, and mode of occurrence. In addition to non-ideal target geometry, such mixed materials also present a heterogeneous target in terms of density. These irregularities violate the assumptions commonly associated with analyses done in the laboratory to achieve the highest possible accuracy. Here we acknowledge the irregularities and we examine the inferences drawn from specific chemical trends obtained on imperfect targets in light of one of the potential pitfalls of natural materials on the surface of Mars, namely thin dust coatings.

  1. Time-resolved double resonance study of J- and K-changing rotational collisional processes in CH3Cl

    NASA Astrophysics Data System (ADS)

    Pape, Travis W.; De Lucia, Frank C.; Skatrud, David D.

    1994-04-01

    Time-resolved double resonance spectroscopy using infrared pump radiation and millimeter-wave and submillimeter-wave probe radiation (IRMMDR) has been used to study rotational energy transfer (RET) in CH3Cl. A collisional energy transfer model using only five parameters for RET plus those needed for vibrational processes is shown to accurately model 350 IRMMDR time responses for two different pump states and 43 probe transitions covering a wide range of rotational states. Previous studies in this laboratory have revealed that J- and K-changing RET have vastly different characters in CH3F [J. Chem. Phys. 92, 6480 (1990)]. Both J- and K-changing RET were accurately modeled with four parameters—one for dipole-dipole collisions, two for the ΔJ scaling law, and one for the cumulative rate of K-changing collisions. As was found for CH3F, J-changing rotational collision rates in CH3Cl are modeled accurately by both the statistical power gap (SPG) law and the infinite order sudden approximation using a power law expression for the basis rates (IOS-P). However, in contrast to CH3F, where all IRMMDR time responses for K-changing collisions have the same shape, many time responses of CH3Cl states populated by K-changing collisions contain an additional early time feature (ETF) that varies with pump and probe states. Nonetheless, a simple generalization of the previously reported model for K-changing collisions is shown to account for all of the additional features observed in CH3Cl. Rather than observing a fixed temperature for K-changing collisions as was the case for CH3F, the temperature is found to be a function of time for CH3Cl. Moreover, the two new parameters this adds to the RET model are related to known physical quantities. A qualitative argument of K-changing collisions based on a classical picture is offered to explain the difference between the measured J- and K-changing state-to-state rates in CH3Cl.

  2. Mechanism of Rock Burst Occurrence in Specially Thick Coal Seam with Rock Parting

    NASA Astrophysics Data System (ADS)

    Wang, Jian-chao; Jiang, Fu-xing; Meng, Xiang-jun; Wang, Xu-you; Zhu, Si-tao; Feng, Yu

    2016-05-01

    Specially thick coal seam with complex construction, such as rock parting and alternative soft and hard coal, is called specially thick coal seam with rock parting (STCSRP), which easily leads to rock burst during mining. Based on the stress distribution of rock parting zone, this study investigated the mechanism, engineering discriminant conditions, prevention methods, and risk evaluation method of rock burst occurrence in STCSRP through setting up a mechanical model. The main conclusions of this study are as follows. (1) When the mining face moves closer to the rock parting zone, the original non-uniform stress of the rock parting zone and the advancing stress of the mining face are combined to intensify gradually the shearing action of coal near the mining face. When the shearing action reaches a certain degree, rock burst easily occurs near the mining face. (2) Rock burst occurrence in STCSRP is positively associated with mining depth, advancing stress concentration factor of the mining face, thickness of rock parting, bursting liability of coal, thickness ratio of rock parting to coal seam, and difference of elastic modulus between rock parting and coal, whereas negatively associated with shear strength. (3) Technologies of large-diameter drilling, coal seam water injection, and deep hole blasting can reduce advancing stress concentration factor, thickness of rock parting, and difference of elastic modulus between rock parting and coal to lower the risk of rock burst in STCSRP. (4) The research result was applied to evaluate and control the risk of rock burst occurrence in STCSRP.

  3. Rapid Construction of a Benzo-Fused Indoxamycin Core Enabled by Site-Selective C-H Functionalizations.

    PubMed

    Bedell, T Aaron; Hone, Graham A B; Valette, Damien; Yu, Jin-Quan; Davies, Huw M L; Sorensen, Erik J

    2016-07-11

    Methods for functionalizing carbon-hydrogen bonds are featured in a new synthesis of the tricyclic core architecture that characterizes the indoxamycin family of secondary metabolites. A unique collaboration between three laboratories has engendered a design for synthesis featuring two sequential C-H functionalization reactions, namely a diastereoselective dirhodium carbene insertion followed by an ester-directed oxidative Heck cyclization, to rapidly assemble the congested tricyclic core of the indoxamycins. This project exemplifies how multi-laboratory collaborations can foster conceptually novel approaches to challenging problems in chemical synthesis. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. BariumCopperChFluorine (Ch = Sulfur, Selenium, Tellurium) p-type transparent conductors

    NASA Astrophysics Data System (ADS)

    Zakutayev, Andriy

    BaCuChF (Ch = S, Se, Te) materials are chalcogen-based transparent conductors with wide optical band gaps (2.9 -- 3.5 eV) and a high concentration of free holes (1018 -- 1020 cm-3 ) caused by the presence of copper vacancies. Chalcogen vacancies compensate copper vacancies in these materials, setting the Fermi level close to the valence band maximum. BaCuChF thin film solid solutions prepared by pulsed laser deposition (PLD) have tunable properties, such as lattice constants, conductivity and optical band gaps. BaCuSF and BaCuSeF materials also feature room-temperature stable 3D excitons with spin-orbit-split levels. BaCuTeF has forbidden lowest-energy optical transitions which extends its transparency range. BaCuChF surfaces oxidize when exposed to air, but can be protected using Ch capping layers. Polycrystalline BaCuSeF thin films have a 4.85 eV work function, a 0.11 eV hole injection barrier into ZnPc, and 0.00 eV valence band offset with ZnTe. BaCuSeF should have s similar band offset and similar interfacial properties with CdTe and Cu(InGa)Se2, and BaCuSF should have no valence band offset with Cu2ZnSnS4, according to the transitivity rule. Therefore, BaCuSeF is suitable for applications as a p-layer in organic light-emitting diodes, p-i-n double-heterojunction and tandem chalcogenide solar cells.

  5. Water Pressure Effects on Strength and Deformability of Fractured Rocks Under Low Confining Pressures

    NASA Astrophysics Data System (ADS)

    Noorian Bidgoli, Majid; Jing, Lanru

    2015-05-01

    The effect of groundwater on strength and deformation behavior of fractured crystalline rocks is one of the important issues for design, performance and safety assessments of surface and subsurface rock engineering problems. However, practical difficulties make the direct in situ and laboratory measurements of these properties of fractured rocks impossible at present, since effects of complex fracture system hidden inside the rock masses cannot be accurately estimated. Therefore, numerical modeling needs to be applied. The overall objective of this paper is to deepen our understanding on the validity of the effective stress concept, and to evaluate the effects of water pressure on strength and deformation parameters. The approach adopted uses discrete element methods to simulate the coupled stress-deformation-flow processes in a fractured rock mass with model dimensions at a representative elementary volume (REV) size and realistic representation of fracture system geometry. The obtained numerical results demonstrate that water pressure has significant influence on the strength, but with minor effects on elastic deformation parameters, compared with significant influence by the lateral confining pressure. Also, the classical effective stress concept to fractured rock can be quite different with that applied in soil mechanics. Therefore, one should be cautious when applying the classical effective stress concept to fractured rock media.

  6. Carbon-Hydrogen (C-H) Bond Activation at PdIV: A Frontier in C-H Functionalization Catalysis.

    PubMed

    Topczewski, Joseph J; Sanford, Melanie S

    2015-01-01

    The direct functionalization of carbon-hydrogen (C-H) bonds has emerged as a versatile strategy for the synthesis and derivatization of organic molecules. Among the methods for C-H bond activation, catalytic processes that utilize a Pd II /Pd IV redox cycle are increasingly common. The C-H activation step in most of these catalytic cycles is thought to occur at a Pd II centre. However, a number of recent reports have suggested the feasibility of C-H cleavage occurring at Pd IV complexes. Importantly, these latter processes often result in complementary reactivity and selectivity relative to analogous transformations at Pd II . This Mini Review highlights proposed examples of C-H activation at Pd IV centres. Applications of this transformation in catalysis as well as mechanistic details obtained from stoichiometric model studies are discussed. Furthermore, challenges and future perspectives for the field are reviewed.

  7. Industrial applications of hot dry rock geothermal energy

    NASA Astrophysics Data System (ADS)

    Duchane, D. V.

    1992-07-01

    Geothermal resources in the form of naturally occurring hot water or steam have been utilized for many years. While these hydrothermal resources are found in many places, the general case is that the rock at depth is hot, but does not contain significant amounts of mobile fluid. An extremely large amount of geothermal energy is found around the world in this hot dry rock (HDR). Technology has been under development for more than twenty years at the Los Alamos National Laboratory in the United States and elsewhere to develop the technology to extract the geothermal energy from HDR in a form useful for electricity generation, space heating, or industrial processing. HDR technology is especially attractive for industrial applications because of the ubiquitous distribution of the HDR resource and the unique aspects of the process developed to recover it. In the HDR process, as developed at Los Alamos, water is pumped down a well under high pressure to open up natural joints in hot rock and create an artificial geothermal reservoir. Energy is extracted by circulating water through the reservoir. Pressurized hot water is returned to the surface through the production well, and its thermal energy is extracted for practical use. The same water is then recirculated through the system to mine more geothermal heat. Construction of a pilot HDR facility at Fenton Hill, NM, USA, has recently been completed by the Los Alamos National Laboratory. It consists of a large underground reservoir, a surface plant, and the connecting wellbores. This paper describes HDR technology and the current status of the development program. Novel industrial applications of geothermal energy based on the unique characteristics of the HDR energy extraction process are discussed.

  8. Rollerjaw Rock Crusher

    NASA Technical Reports Server (NTRS)

    Peters, Gregory; Brown, Kyle; Fuerstenau, Stephen

    2009-01-01

    The rollerjaw rock crusher melds the concepts of jaw crushing and roll crushing long employed in the mining and rock-crushing industries. Rollerjaw rock crushers have been proposed for inclusion in geological exploration missions on Mars, where they would be used to pulverize rock samples into powders in the tens of micrometer particle size range required for analysis by scientific instruments.

  9. Methane Provenance Determined by CH2D2 and 13CH3D Abundances

    NASA Astrophysics Data System (ADS)

    Kohl, I. E.; Giunta, T.; Warr, O.; Ash, J. L.; Ruffine, L.; Sherwood Lollar, B.; Young, E. D.

    2017-12-01

    Determining the provenance of naturally occurring methane gases is of major interest to energy companies and atmospheric climate modelers, among others. Bulk isotopic compositions and other geochemical tracers sometimes fail to provide definitive determinations of sources of methane due to complications from mixing and complicated chemical pathways of origin. Recent measurements of doubly-substituted isotopologues of methane, CH2D2 (UCLA) and 13CH3D (UCLA, CalTech, and MIT) have allowed for major improvements in sourcing natural methane gases. Early work has focused on formation temperatures obtained when the relative abundances of both doubly-substituted mass-18 species are consistent with internal equilibrium. When methane gases do not plot on the thermodynamic equilibrium curve in D12CH2D2 vs D13CH3D space, temperatures determined from D13CH3D values alone are usually spurious, even when appearing reasonable. We find that the equilibrium case is actually rare and almost exclusive to thermogenic gases produced at temperatures exceeding 100°C. All other relevant methane production processes appear to generate gases that are not in isotopologue-temperature equilibrium. When gases show departures from equilibrium as determined by the relationship between CH2D2 and 13CH3D abundances, data fall within empirically defined fields representing formation pathways. These fields are thus far consistent between different geological settings and and between lab experiments and natural samples. We have now defined fields for thermogenic gas production, microbial methanogenesis, low temperature abiotic (Sabatier) synthesis and higher temperature FTT synthesis. The majority of our natural methane data can be explained by mixing between end members originating within these production fields. Mixing can appear complex, resulting in both hyper-clumped and anti-clumped isotopologue abundances. In systems where mixtures dominate and end-members are difficult to sample, mixing models

  10. Content of children's loss of control eating episodes assessed by self-report and laboratory test meal

    PubMed Central

    Theim, Kelly R.; Wilfley, Denise E.; Beach, Elizabeth; Tanofsky-Kraff, Marian; Goldschmidt, Andrea B.

    2014-01-01

    Pediatric loss of control (LOC) eating heightens risk for excessive weight gain and further disordered eating. Assessment of LOC typically involves self-report interview or laboratory test meal, although no study has concurrently examined data from both methods. We gathered eating episode data via interview (Child Eating Disorder Examination; ChEDE) and a laboratory test meal, among 22 overweight girls (aged 7-12 years) reporting LOC eating. Children consumed more energy during ChEDE episodes, although ChEDE and test meal episodes did not differ in macronutrient content. Episodes' correlation for amount consumed (grams) did not reach significance, p=.076. In exploratory analyses among the 7 children reporting LOC during the test meal, episodes were significantly correlated for grams consumed. Findings provide preliminary data to suggest that semi-structured interviews accurately capture children's LOC episode quantity. Episodes did not qualitatively differ, although children reported consuming more energy during self-reported episodes. Replication is warranted in larger studies. PMID:24019221

  11. Test Plan: WIPP bin-scale CH TRU waste tests

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Molecke, M.A.

    1990-08-01

    This WIPP Bin-Scale CH TRU Waste Test program described herein will provide relevant composition and kinetic rate data on gas generation and consumption resulting from TRU waste degradation, as impacted by synergistic interactions due to multiple degradation modes, waste form preparation, long-term repository environmental effects, engineered barrier materials, and, possibly, engineered modifications to be developed. Similar data on waste-brine leachate compositions and potentially hazardous volatile organic compounds released by the wastes will also be provided. The quantitative data output from these tests and associated technical expertise are required by the WIPP Performance Assessment (PA) program studies, and for the scientificmore » benefit of the overall WIPP project. This Test Plan describes the necessary scientific and technical aspects, justifications, and rational for successfully initiating and conducting the WIPP Bin-Scale CH TRU Waste Test program. This Test Plan is the controlling scientific design definition and overall requirements document for this WIPP in situ test, as defined by Sandia National Laboratories (SNL), scientific advisor to the US Department of Energy, WIPP Project Office (DOE/WPO). 55 refs., 16 figs., 19 tabs.« less

  12. A Collaborative Study of Source Apportionment and Total City Emissions of CH4 from Indianapolis

    NASA Astrophysics Data System (ADS)

    Hajny, K. D.; Davis, K. J.; Franklin, J. E.; Harvey, R. M.; Lavoie, T. N.; Miles, N. L.; Richardson, S.; Salmon, O. E.; Sarmiento, D. P.; Shepson, P. B.; Stirm, B. H.; Wofsy, S.

    2016-12-01

    Methane (CH4) is the second most important greenhouse gas emitted in the United States, accounting for about 11% of all US greenhouse gas emissions in 2014. Over 60% of CH4 emissions globally are due to human activity and two of the largest anthropogenic sources of CH4 are waste decomposition in landfills and losses from the energy sector. Indianapolis has been a testbed site for development of methods for quantitative urban-scale greenhouse gas emissions measurements, through the Indianapolis Flux Experiment (INFLUX) since 2010. Multiple airborne mass balance experiments with Purdue University's Airborne Laboratory for Atmospheric Research (ALAR) have been performed in the area to quantify greenhouse gas emissions, since 2008. Previous research has shown that the large landfill in Indianapolis is the only significant point source, emitting 45 ± 14 mols CH4/s or roughly 1/3 of all CH4 emissions. Propane/methane ratios have indicated that all other CH4 emissions were due to leaks in the natural gas distribution system in the city, but not all the sources have been identified. A recent collaborative effort aimed to investigate this further using tower based inversions from INFLUX data, ground based Lagrangian transport modeling using Fourier Transform Spectrometers, and airborne based mass balance experiments using ALAR. Within the 2-week long project there were 4 days with atmospheric conditions that allowed for simultaneous airborne and ground based measurements. Here we will discuss selected outcomes from this effort, including city-wide mass balance measurements from ALAR, our results in light of the FTS observations, and how the results compare to the historical data base for Indianapolis.

  13. Fractured rock stress-permeability relationships from in situ data and effects of temperature and chemical-mechanical couplings

    DOE PAGES

    Rutqvist, J.

    2014-09-19

    The purpose of this paper is to (i) review field data on stress-induced permeability changes in fractured rock; (ii) describe estimation of fractured rock stress-permeability relationships through model calibration against such field data; and (iii) discuss observations of temperature and chemically mediated fracture closure and its effect on fractured rock permeability. The field data that are reviewed include in situ block experiments, excavation-induced changes in permeability around tunnels, borehole injection experiments, depth (and stress) dependent permeability, and permeability changes associated with a large-scale rock-mass heating experiment. Data show how the stress-permeability relationship of fractured rock very much depends on localmore » in situ conditions, such as fracture shear offset and fracture infilling by mineral precipitation. Field and laboratory experiments involving temperature have shown significant temperature-driven fracture closure even under constant stress. Such temperature-driven fracture closure has been described as thermal overclosure and relates to better fitting of opposing fracture surfaces at high temperatures, or is attributed to chemically mediated fracture closure related to pressure solution (and compaction) of stressed fracture surface asperities. Back-calculated stress-permeability relationships from field data may implicitly account for such effects, but the relative contribution of purely thermal-mechanical and chemically mediated changes is difficult to isolate. Therefore, it is concluded that further laboratory and in situ experiments are needed to increase the knowledge of the true mechanisms behind thermally driven fracture closure, and to further assess the importance of chemical-mechanical coupling for the long-term evolution of fractured rock permeability.« less

  14. Fractured rock stress-permeability relationships from in situ data and effects of temperature and chemical-mechanical couplings

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rutqvist, J.

    The purpose of this paper is to (i) review field data on stress-induced permeability changes in fractured rock; (ii) describe estimation of fractured rock stress-permeability relationships through model calibration against such field data; and (iii) discuss observations of temperature and chemically mediated fracture closure and its effect on fractured rock permeability. The field data that are reviewed include in situ block experiments, excavation-induced changes in permeability around tunnels, borehole injection experiments, depth (and stress) dependent permeability, and permeability changes associated with a large-scale rock-mass heating experiment. Data show how the stress-permeability relationship of fractured rock very much depends on localmore » in situ conditions, such as fracture shear offset and fracture infilling by mineral precipitation. Field and laboratory experiments involving temperature have shown significant temperature-driven fracture closure even under constant stress. Such temperature-driven fracture closure has been described as thermal overclosure and relates to better fitting of opposing fracture surfaces at high temperatures, or is attributed to chemically mediated fracture closure related to pressure solution (and compaction) of stressed fracture surface asperities. Back-calculated stress-permeability relationships from field data may implicitly account for such effects, but the relative contribution of purely thermal-mechanical and chemically mediated changes is difficult to isolate. Therefore, it is concluded that further laboratory and in situ experiments are needed to increase the knowledge of the true mechanisms behind thermally driven fracture closure, and to further assess the importance of chemical-mechanical coupling for the long-term evolution of fractured rock permeability.« less

  15. Studies of soft x-ray transmission through grid supported CH layers

    NASA Astrophysics Data System (ADS)

    Davis, J. S.; Keiter, P. A.; Klein, S. R.; Frank, Y.; Drake, R. P.; Shvarts, D.

    2017-10-01

    Recent experiments have shown that it may be possible to use laser-heated high-Z foils to drive new radiation transport (RadTran) experiments in gas fill tubes. These tubes must be pressurized above 1atm and the x-ray source needs to be physically separated from the gas. To achieve this, a grid-supported CH seal is implemented. The grid reduces the total surface area of the gas-seal interaction region lowering the thickness requirements for the CH layer. However, as mesh spacing is reduced, hole closure from wire ablation may reduce the x-ray flux. To optimize the seal design, experiments were performed measuring x-ray transmission through CH layers supported by meshes composed of copper, gold, or stainless steel and using hexagonal or square mesh geometries. The x-ray source was formed by heating a 0.5 μm thick planar gold foil with a 4 ns laser pulse at an intensity of 2 ×1014 W / cm 2. Emission data was collected using an x-ray framing camera and a Dante photodiode array. Experiments show that the CH layers can reach effective temperatures of nearly 100 eV but mesh design significantly affects performance, with a nearly 20 eV difference between the best and worst performing seal targets. This talk will discuss our findings and their impact on future RadTran experiments. This work is funded by the U.S. DOE, through the NNSA-DS and SC-OFES Joint Program in HED Laboratory Plasmas, Grant Number DE-NA0001840, the National LUFP, Grant Number DE-NA0000850, and through NNSA/OICF under Cooperatvie Agreement No. DE-FC52-08NA2830.

  16. Strain Localization and Weakening Processes in Viscously Deforming Rocks: Numerical Modeling Based on Laboratory Torsion Experiments

    NASA Astrophysics Data System (ADS)

    Doehmann, M.; Brune, S.; Nardini, L.; Rybacki, E.; Dresen, G.

    2017-12-01

    Strain localization is an ubiquitous process in earth materials observed over a broad range of scales in space and time. Localized deformation and the formation of shear zones and faults typically involves material softening by various processes, like shear heating and grain size reduction. Numerical modeling enables us to study the complex physical and chemical weakening processes by separating the effect of individual parameters and boundary conditions. Using simple piece-wise linear functions for the parametrization of weakening processes allows studying a system at a chosen (lower) level of complexity (e.g. Cyprych et al., 2016). In this study, we utilize a finite element model to test two weakening laws that reduce the strength of the material depending on either the I) amount of accumulated strain or II) deformational work. Our 2D Cartesian models are benchmarked to single inclusion torsion experiments performed at elevated temperatures of 900 °C and pressures of up to 400 MPa (Rybacki et al., 2014). The experiments were performed on Carrara marble samples containing a weak Solnhofen limestone inclusion at a maximum strain rate of 2.0*10-4 s-1. Our models are designed to reproduce shear deformation of a hollow cylinder equivalent to the laboratory setup, such that material leaving one side of the model in shear direction enters again on the opposite side using periodic boundary conditions. Similar to the laboratory tests, we applied constant strain rate and constant stress boundary conditions.We use our model to investigate the time-dependent distribution of stress and strain and the effect of different parameters. For instance, inclusion rotation is shown to be strongly dependent on the viscosity ratio between matrix and inclusion and stronger ductile weakening increases the localization rate while decreasing shear zone width. The most suitable weakening law for representation of ductile rock is determined by combining the results of parameter tests with

  17. The Design of The Monitoring Tools Of Clean Air Condition And Dangerous Gas CO, CO2 CH4 In Chemical Laboratory By Using Fuzzy Logic Based On Microcontroller

    NASA Astrophysics Data System (ADS)

    Widodo, Slamet; Miftakul, Amin M.; Sutrisman, Adi

    2018-02-01

    There are many phenomena that human are exposed to toxins from certain types such as of CO2, CO2 and CH4 gases. The device used to detect large amounts of CO, CO2, and CH4 gas in air in enclosed spaces using MQ 135 gas sensors of different types based on the three sensitivity of the Gas. The results of testing the use of sensors MQ 135 on the gas content of CO, CO2 and CH4 received by the sensor is still in the form of ppm based on the maximum ppm detection range of each sensor. Active sensor detects CO 120 ppm gas, CO2 1600 ppm and CH4 1ppm "standby 1" air condition with intermediate rotary fan. Active sensor detects CO 30 ppm gas, CO2 490 ppm and CH4 7 ppm "Standby 2" with low rotating fan output. Fuzzy rulebase logic for motor speed when gas detection sensor CO, CO2, and CH4 output controls the motion speed of the fan blower. Active sensors detect CO 15 ppm, CO2 320 ppm and CH4 45 ppm "Danger" air condition with high fan spin fan. At the gas level of CO 15 ppm, CO2 390 ppm and CH4 3 ppm detect "normal" AC sensor with fan output stop spinning.

  18. The catalytic effects of H2CO3, CH3COOH, HCOOH and H2O on the addition reaction of CH2OO + H2O → CH2(OH)OOH

    NASA Astrophysics Data System (ADS)

    Zhang, Tianlei; Lan, Xinguang; Wang, Rui; Roy, Soumendra; Qiao, Zhangyu; Lu, Yousong; Wang, Zhuqing

    2018-07-01

    The addition reaction of CH2OO + H2O → CH2(OH)OOH without and with X (X = H2CO3, CH3COOH and HCOOH) and H2O was studied at CCSD(T)/6-311+ G(3df,2dp)//B3LYP/6-311+G(2d,2p) level of theory. Our results show that X can catalyse CH2OO + H2O → CH2(OH)OOH reaction both by increasing the number of rings, and by adding the size of the ring in which ring enlargement by COOH moiety of X inserting into CH2OO...H2O is favourable one. Water-assisted CH2OO + H2O → CH2(OH)OOH can occur by H2O moiety of (H2O)2 or the whole (H2O)2 forming cyclic structure with CH2OO, where the latter form is more favourable. Because the concentration of H2CO3 is unknown, the influence of CH3COOH, HCOOH and H2O were calculated within 0-30 km altitude of the Earth's atmosphere. The results calculated within 0-5 km altitude show that H2O and HCOOH have obvious effect on enhancing the rate with the enhancement factors are, respectively, 62.47%-77.26% and 0.04%-1.76%. Within 5-30 km altitude, HCOOH has obvious effect on enhancing the title rate with the enhancement factor of 2.69%-98.28%. However, compared with the reaction of CH2OO + HCOOH, the rate of CH2OO...H2O + HCOOH is much slower.

  19. Training Management in the CH-46E Community After MAWTS-1 Stands Down Its CH-46E Division

    DTIC Science & Technology

    2012-04-23

    SHOULD INCLUDE THE FOREGOING STATEMENT. QUOTATION FROM, ABSTRACTION FROM, OR REPRODUCTION OF ALL OR ANY PART OF THIS DOCUMENT IS PERMITTED...HMH) currently fly either the CH-53D Sea Stallion or the CH-53E Super Stallion helicopters. Those units that fly the CH-53D Sea Stallion are in the...process of converting to the CH-53E Super Stallion or will transition the squadrons to medium lift assault support platforms.5 The HMHs currently

  20. 4D Visualization of Experimental Procedures in Rock Physics

    NASA Astrophysics Data System (ADS)

    Vanorio, T.; di Bonito, C.

    2010-12-01

    Engaging students in laboratory classes in geophysics is becoming more and more difficult. This is primarily because of an ever-widening gap between the less appealing aspects that characterize these courses (e.g., lengthiness of the experimental operations, high student/instrument ratio, limited time associated with lack of previous hands-on experiences, and logistical and safety concerns) and the life style of the 21st century generations (i.e., extensive practice to high-tech tools, high-speed communications and computing, 3D graphics and HD videos). To bridge the gap and enhance the teaching strategy of laboratory courses in geophysics, we have created simulator-training tools for use in preparation for the actual experimental phase. We are using a modeling, animation, and rendering package to create (a) 3D models that accurately reproduce actual scenarios and instruments used for the measurement of rock physics properties and (b) 4D interactive animations that simulate hands-on demonstrations of the experimental procedures. We present here a prototype describing step-by-step the experimental protocol and the principles behind the measurement of rock porosity. The tool reproduces an actual helium porosimeter and makes use of interactive animations, guided text, and a narrative voice guiding the audience through the different phases of the experimental process. Our strategy is to make the most of new technologies while preserving the accuracy of classical laboratory methods and practices. These simulations are not intended to replace traditional lab work; rather they provide students with the opportunity for review and repetition. The primary goal is thus to help students familiarize themselves during their earlier curricula with lab methodologies, thus minimizing apparent hesitation and frustration in later classes. This may also increase the level of interest and involvement of undergraduate students and, in turn, enhance their keenness to pursue their

  1. Experimental research data on stress state of salt rock mass around an underground excavation

    NASA Astrophysics Data System (ADS)

    Baryshnikov, VD; Baryshnikov, DV

    2018-03-01

    The paper presents the experimental stress state data obtained in surrounding salt rock mass around an excavation in Mir Mine, ALROSA. The deformation characteristics and the values of stresses in the adjacent rock mass are determined. Using the method of drilling a pair of parallel holes in a stressed area, the authors construct linear relationship for the radial displacements of the stress measurement hole boundaries under the short-term loading of the perturbing hole. The resultant elasticity moduli of rocks are comparable with the laboratory core test data. Pre-estimates of actual stresses point at the presence of a plasticity zone in the vicinity of the underground excavation. The stress state behavior at a distance from the excavation boundary disagrees with the Dinnik–Geim hypothesis.

  2. Theory of wing rock

    NASA Technical Reports Server (NTRS)

    Hsu, C.-H.; Lan, C. E.

    1985-01-01

    Wing rock is one type of lateral-directional instabilities at high angles of attack. To predict wing rock characteristics and to design airplanes to avoid wing rock, parameters affecting wing rock characteristics must be known. A new nonlinear aerodynamic model is developed to investigate the main aerodynamic nonlinearities causing wing rock. In the present theory, the Beecham-Titchener asymptotic method is used to derive expressions for the limit-cycle amplitude and frequency of wing rock from nonlinear flight dynamics equations. The resulting expressions are capable of explaining the existence of wing rock for all types of aircraft. Wing rock is developed by negative or weakly positive roll damping, and sustained by nonlinear aerodynamic roll damping. Good agreement between theoretical and experimental results is obtained.

  3. Degraded Land Restoration in Reinstating CH4 Sink

    PubMed Central

    Singh, Jay Shankar; Gupta, Vijai K.

    2016-01-01

    Methane (CH4), a potent greenhouse gas, contributes about one third to the global green house gas emissions. CH4-assimilating microbes (mostly methanotrophs) in upland soils play very crucial role in mitigating the CH4 release into the atmosphere. Agricultural, environmental, and climatic shifts can alter CH4 sink profiles of soils, likely through shifts in CH4-assimilating microbial community structure and function. Landuse change, as forest and grassland ecosystems altered to agro-ecosystems, has already attenuated the soil CH4 sink potential, and are expected to be continued in the future. We hypothesized that variations in CH4 uptake rates in soils under different landuse practices could be an indicative of alterations in the abundance and/or type of methanotrophic communities in such soils. However, only a few studies have addressed to number and methanotrophs diversity and their correlation with the CH4 sink potential in soils of rehabilitated/restored lands. We focus on landuse practices that can potentially mitigate CH4 gas emissions, the most prominent of which are improved cropland, grazing land management, use of bio-fertilizers, and restoration of degraded lands. In this perspective paper, it is proposed that restoration of degraded lands can contribute considerably to improved soil CH4 sink strength by retrieving/conserving abundance and assortment of efficient methanotrophic communities. We believe that this report can assist in identifying future experimental directions to the relationships between landuse changes, methane-assimilating microbial communities and soil CH4 sinks. The exploitation of microbial communities other than methanotrophs can contribute significantly to the global CH4 sink potential and can add value in mitigating the CH4 problems. PMID:27379053

  4. Degraded Land Restoration in Reinstating CH4 Sink.

    PubMed

    Singh, Jay Shankar; Gupta, Vijai K

    2016-01-01

    Methane (CH4), a potent greenhouse gas, contributes about one third to the global green house gas emissions. CH4-assimilating microbes (mostly methanotrophs) in upland soils play very crucial role in mitigating the CH4 release into the atmosphere. Agricultural, environmental, and climatic shifts can alter CH4 sink profiles of soils, likely through shifts in CH4-assimilating microbial community structure and function. Landuse change, as forest and grassland ecosystems altered to agro-ecosystems, has already attenuated the soil CH4 sink potential, and are expected to be continued in the future. We hypothesized that variations in CH4 uptake rates in soils under different landuse practices could be an indicative of alterations in the abundance and/or type of methanotrophic communities in such soils. However, only a few studies have addressed to number and methanotrophs diversity and their correlation with the CH4 sink potential in soils of rehabilitated/restored lands. We focus on landuse practices that can potentially mitigate CH4 gas emissions, the most prominent of which are improved cropland, grazing land management, use of bio-fertilizers, and restoration of degraded lands. In this perspective paper, it is proposed that restoration of degraded lands can contribute considerably to improved soil CH4 sink strength by retrieving/conserving abundance and assortment of efficient methanotrophic communities. We believe that this report can assist in identifying future experimental directions to the relationships between landuse changes, methane-assimilating microbial communities and soil CH4 sinks. The exploitation of microbial communities other than methanotrophs can contribute significantly to the global CH4 sink potential and can add value in mitigating the CH4 problems.

  5. Constraining the sources of CH4 emissions during past abrupt climate change using CH4 triple isotopes mass balance from the ice core records

    NASA Astrophysics Data System (ADS)

    Dyonisius, M.; Petrenko, V. V.; Smith, A. W.; Hmiel, B.; Beck, J.; Seth, B.; Bock, M.; Hua, Q.; Yang, B.; Harth, C. M.; Beaudette, R.; Lee, J.; Erhardt, T.; Schmitt, J.; Brook, E.; Weiss, R. F.; Fischer, H.; Severinghaus, J. P.

    2017-12-01

    Methane (CH4) is the third most important greenhouse gas in the atmosphere after water vapor and CO2. Understanding how the natural CH4 budget has changed in response to changing climate in the past can provide insights on the sensitivity of the natural CH4 emissions to the current anthropogenic warming. CH4 isotopes (Δ14CH4, δ13C-CH4, and δD-CH4) from ice cores can be used to fingerprint the sources of CH4 increases in the past. We have successfully extracted 6 large volume (>1000kg) ice core samples from Taylor Glacier, Antarctica spanning the Oldest Dryas-Bølling transition ( 14.7ka) - the first abrupt warming and CH4 rise since the Last Glacial Maximum. Among the CH4 isotopes, our Δ 14CH4 data are unique in their ability to unambiguously distinguish between "old" CH4 sources (e.g. marine clathrate, geologic sources, old permafrost) and "modern" CH4 sources (e.g. tropical and boreal wetlands). Our Δ14CH4 data unambiguously rule out marine clathrate and old permafrost as the sources of the abrupt CH4 rise. Preliminary CH4 stable isotopes box modeling combined with interpolar CH4 concentration gradient from existing ice core records suggest that tropical wetlands were the dominant driver for the Oldest Dryas-Bølling CH4 rise.

  6. Laboratory experiments duplicate conditions in the Earth’s crust

    USGS Publications Warehouse

    Peselnick, L.; Dieterich, J.H.; Stewart, R.M.

    1974-01-01

    An experimental device that simulates conditions in the Earth's crust at depths of up to 30 kilometers has been constructed by geophysicists working at the U.S Geological Survey laboratories in Menlo Park, California. A high pressure "bomb" is being used to experimentally measure the velocity of seismic waves in different types of rock at various confining pressures and temperatures. The principal purpose of these measurements is to determine the elastic and non-elastic properties of rocks and minerals under conditions of high-pressure such as exist deep in the Earth's crust. 

  7. Powder X-ray diffraction laboratory, Reston, Virginia

    USGS Publications Warehouse

    Piatak, Nadine M.; Dulong, Frank T.; Jackson, John C.; Folger, Helen W.

    2014-01-01

    The powder x-ray diffraction (XRD) laboratory is managed jointly by the Eastern Mineral and Environmental Resources and Eastern Energy Resources Science Centers. Laboratory scientists collaborate on a wide variety of research problems involving other U.S. Geological Survey (USGS) science centers and government agencies, universities, and industry. Capabilities include identification and quantification of crystalline and amorphous phases, and crystallographic and atomic structure analysis for a wide variety of sample media. Customized laboratory procedures and analyses commonly are used to characterize non-routine samples including, but not limited to, organic and inorganic components in petroleum source rocks, ore and mine waste, clay minerals, and glassy phases. Procedures can be adapted to meet a variety of research objectives.

  8. Mild Palladium Catalyzed ortho C-H Bond Functionalizations of Aniline Derivatives.

    PubMed

    Tischler, Ms Orsolya; Tóth, Mr Balázs; Novák, Zoltán

    2017-02-01

    This account collects the developments and transformations which avoid the utilization of harsh reaction conditions in the field of palladium catalyzed, ortho-directed C-H activation of aniline derivatives from the first attempts to up-to-date results, including the results of our research laboratory. The discussed functionalizations performed under mild conditions include acylation, olefination, arylation, alkylation, alkoxylation reactions. Beside the optimization studies and the synthetic applications mechanistic investigations are also presented. © 2017 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Mobilization and Transport of Organic Compounds from Reservoir Rock and Caprock in Geological Carbon Sequestration Sites

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zhong, Lirong; Cantrell, Kirk J.; Mitroshkov, Alexandre V.

    2014-05-06

    Supercritical CO2 (scCO2) is an excellent solvent for organic compounds, including benzene, toluene, ethyl-benzene, and xylene (BTEX), phenols, and polycyclic aromatic hydrocarbons (PAHs). Monitoring results from geological carbon sequestration (GCS) field tests has shown that organic compounds are mobilized following CO2 injection. Such results have raised concerns regarding the potential for groundwater contamination by toxic organic compounds mobilized during GCS. Knowledge of the mobilization mechanism of organic compounds and their transport and fate in the subsurface is essential for assessing risks associated with GCS. Extraction tests using scCO2 and methylene chloride (CH2Cl2) were conducted to study the mobilization of volatilemore » organic compounds (VOCs, including BTEX), the PAH naphthalene, and n-alkanes (n-C20 – n-C30) by scCO2 from representative reservoir rock and caprock obtained from depleted oil reservoirs and coal from an enhanced coal-bed methane recovery site. More VOCs and naphthalene were extractable by scCO2 compared to the CH2Cl2 extractions, while scCO2 extractable alkane concentrations were much lower than concentrations extractable by CH2Cl2. In addition, dry scCO2 was found to extract more VOCs than water saturated scCO2, but water saturated scCO2 mobilized more naphthalene than dry scCO2. In sand column experiments, moisture content was found to have an important influence on the transport of the organic compounds. In dry sand columns the majority of the compounds were retained in the column except benzene and toluene. In wet sand columns the mobility of the BTEX was much higher than that of naphthalene. Based upon results determined for the reservoir rock, caprock, and coal samples studied here, the risk to aquifers from contamination by organic compounds appears to be relatively low; however, further work is necessary to fully evaluate risks from depleted oil reservoirs.« less

  10. Pore Characterization of Shale Rock and Shale Interaction with Fluids at Reservoir Pressure-Temperature Conditions Using Small-Angle Neutron Scattering

    NASA Astrophysics Data System (ADS)

    Ding, M.; Hjelm, R.; Watkins, E.; Xu, H.; Pawar, R.

    2015-12-01

    Oil/gas produced from unconventional reservoirs has become strategically important for the US domestic energy independence. In unconventional realm, hydrocarbons are generated and stored in nanopores media ranging from a few to hundreds of nanometers. Fundamental knowledge of coupled thermo-hydro-mechanical-chemical (THMC) processes that control fluid flow and propagation within nano-pore confinement is critical for maximizing unconventional oil/gas production. The size and confinement of the nanometer pores creates many complex rock-fluid interface interactions. It is imperative to promote innovative experimental studies to decipher physical and chemical processes at the nanopore scale that govern hydrocarbon generation and mass transport of hydrocarbon mixtures in tight shale and other low permeability formations at reservoir pressure-temperature conditions. We have carried out laboratory investigations exploring quantitative relationship between pore characteristics of the Wolfcamp shale from Western Texas and the shale interaction with fluids at reservoir P-T conditions using small-angle neutron scattering (SANS). We have performed SANS measurements of the shale rock in single fluid (e.g., H2O and D2O) and multifluid (CH4/(30% H2O+70% D2O)) systems at various pressures up to 20000 psi and temperature up to 150 oF. Figure 1 shows our SANS data at different pressures with H2O as the pressure medium. Our data analysis using IRENA software suggests that the principal changes of pore volume in the shale occurred on smaller than 50 nm pores and pressure at 5000 psi (Figure 2). Our results also suggest that with increasing P, more water flows into pores; with decreasing P, water is retained in the pores.

  11. Evaluation of Used Fuel Disposition in Clay-Bearing Rock

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jove-Colon, Carlos F.; Weck, Philippe F.; Hammond, Glenn Edward

    Deep geological disposal of nuclear waste in clay/shale/argillaceous rock formations has received much consideration given its desirable attributes such as isolation properties (low permeability), geochemically reduced conditions, slow diffusion, sorbtive mineralogy, and geologically widespread (Jové Colón et al., 2014). There is a wealth of gained scientific expertise on the behavior of clay/shale/ argillaceous rock given its focus in international nuclear waste repository programs that includes underground research laboratories (URLs) in Switzerland, France, Belgium, and Japan. Jové Colón et al. (2014) have described some of these investigative efforts in clay rock ranging from site characterization to research on the engineered barriermore » system (EBS). Evaluations of disposal options that include nuclear waste disposition in clay/shale/argillaceous rock have determined that this host media can accommodate a wide range of waste types. R&D work within the Used Fuel Disposition Campaign (UFDC) assessing thermal effects and fluid-mineral interactions for the disposition of heat-generating waste have so far demonstrated the feasibility for the EBS and clay host rock to withstand high thermal loads. This report represents the continuation of disposal R&D efforts on the advancement and refinement of coupled Thermal-Hydrological-Mechanical-Chemical (THMC), hydrothermal experiments on clay interactions, used fuel degradation (source term), and thermodynamic modeling and database development. The development and implementation of a clay/shale/argillite reference case described in Jové Colón et al. (2014) for FY15 will be documented in another report (Mariner et al. 2015) – only a brief description will be given here. This clay reference case implementation is the result of integration efforts between the GDSA PA and disposal in argillite work packages. The assessment of sacrificial zones in the EBS is being addressed through experimental work along with 1D

  12. CH3OCH3 in Orion-KL: a striking similarity with HCOOCH3

    NASA Astrophysics Data System (ADS)

    Brouillet, N.; Despois, D.; Baudry, A.; Peng, T.-C.; Favre, C.; Wootten, A.; Remijan, A. J.; Wilson, T. L.; Combes, F.; Wlodarczak, G.

    2013-02-01

    Context. Orion-KL is a remarkable, nearby star-forming region where a recent explosive event has generated shocks that could have released complex molecules from the grain mantles. Aims: A comparison of the distribution of the different complex molecules will help in understanding their formation and constraining the chemical models. Methods: We used several data sets from the Plateau de Bure Interferometer to map the dimethyl ether emission with different arcsec spatial resolutions and different energy levels (from Eup = 18 to 330 K) to compare with our previous methyl formate maps. Results: Our data show remarkable similarity between the dimethyl ether (CH3OCH3) and the methyl formate (HCOOCH3) distributions even on a small scale (1.8″ × 0.8″ or ~500 AU). This long suspected similarity, seen from both observational and theoretical arguments, is demonstrated with unprecedented confidence, with a correlation coefficient of maps ~0.8. Conclusions: A common precursor is the simplest explanation of our correlation. Comparisons with previous laboratory work and chemical models suggest the major role of grain surface chemistry and a recent release, probably with little processing, of mantle molecules by shocks. In this case the CH3O radical produced from methanol ice would be the common precursor (whereas ethanol, C2H5OH, is produced from the radical CH2OH). The alternative gas phase scheme, where protonated methanol CH3OH+2 is the common precursor to produce methyl formate and dimethyl ether through reactions with HCOOH and CH3OH, is also compatible with our data. Our observations cannot yet definitely allow a choice between the different chemical processes, but the tight correlation between the distributions of HCOOCH3 and CH3OCH3 strongly contrasts with the different behavior we observe for the distributions of ethanol and formic acid. This provides a very significant constraint on models. Based on observations carried out with the IRAM Plateau de Bure

  13. A Mechanistical Study on the Formation of Dimethyl Ether (CH3OCH3) and Ethanol (CH3CH2OH) in Methanol-containing Ices and Implications for the Chemistry of Star-forming Regions

    NASA Astrophysics Data System (ADS)

    Bergantini, Alexandre; Góbi, Sándor; Abplanalp, Matthew J.; Kaiser, Ralf I.

    2018-01-01

    The underlying formation mechanisms of complex organic molecules (COMs)—in particular, structural isomers—in the interstellar medium (ISM) are largely elusive. Here, we report new experimental findings on the role of methanol (CH3OH) and methane (CH4) ices in the synthesis of two C2H6O isomers upon interaction with ionizing radiation: ethanol (CH3CH2OH) and dimethyl ether (CH3OCH3). The present study reproduces the interstellar abundance ratios of both species with ethanol to dimethyl ether branching ratios of (2.33 ± 0.14):1 suggesting that methanol and methane represents the key precursor to both isomers within interstellar ices. Exploiting isotopic labeling combined with reflectron time-of-flight mass spectrometry (Re-TOF-MS) after isomer selective vacuum ultra-violet (VUV) photoionization of the neutral molecules, we also determine the formation mechanisms of both isomers via radical–radical recombination versus carbene (CH2) insertion with the former pathway being predominant. Formation routes to higher molecular weight reaction products such as ethylene glycol (HOCH2CH2OH), dimethyl peroxide (CH3OOCH3), and methoxymethanol (CH3OCH2OH) are discussed briefly as well.

  14. An Online Social Networking Approach to Reinforce Learning of Rocks and Minerals

    ERIC Educational Resources Information Center

    Kennelly, Patrick

    2009-01-01

    Numerous and varied methods are used in introductory Earth science and geology classes to help students learn about rocks and minerals, such as classroom lectures, laboratory specimen identification, and field trips. This paper reports on a method using online social networking. The choice of this forum was based on two criteria. First, many…

  15. Discrimination of alkalinity in granitoid Rocks: A potential TIMS application

    NASA Technical Reports Server (NTRS)

    Ruff, Steven W.

    1995-01-01

    In mineral exploration, the ability to distinguish and map petrochemical variations of magmatic rocks can be a useful reconnaissance tool. Alkalinity is one such petrochemical parameter and is used in the characterization of granitoid rocks. In quartz normative plutonic rocks, alkalinity is related to the composition and abundance of feldspars. Together with quartz abundance, knowledge of feldspar modes allows the classification of these igneous rocks according to the Streckeisen diagram. Alternative classification schemes rely on whole rock geochemistry instead of mineral identifications. The relative ease of obtaining whole rock analyses means that geochemical classifications tend to be favored in exploration geology. But the technique of thermal infrared spectroscopy of rocks yields information on mineralogy and is one that can be applied remotely. The goal of the current work then is to establish whether data from TIMS can be used to distinguish the mineralogical variations that relate to alkalinity. An ideal opportunity to test this thesis arises from the work presented in a paper by Dewitt (1989). This paper contains the results of mapping and analysis of Proterozoic plutonic rocks in north-central Arizona. The map resulting from this work delineates plutons according to alkalinity in an effort to establish a trend or polarity in the regional magmatism. Also contained within this paper are brief descriptions of the mineralogy of half of the region's plutons. This combination of mineralogical and geochemical information was the rationale behind choosing this area as a site for TIMS over flights. A portion of the region centered on the northern Bradshaw Mountains was selected because it contains plutons of all three alkalinity classifications (alkali-calcic, calc-alkalic, and calic) present on DeWitt's map within a relatively small area. The site was flown in August of 1994 and the data received a few days before the writing of this manuscript. Most of this

  16. Reconnaissance studies of potential petroleum source rocks in the Middle Jurassic Tuxedni Group near Red Glacier, eastern slope of Iliamna Volcano

    USGS Publications Warehouse

    Stanley, Richard G.; Herriott, Trystan M.; LePain, David L.; Helmold, Kenneth P.; Peterson, C. Shaun

    2013-01-01

    Previous geological and organic geochemical studies have concluded that organic-rich marine shale in the Middle Jurassic Tuxedni Group is the principal source rock of oil and associated gas in Cook Inlet (Magoon and Anders, 1992; Magoon, 1994; Lillis and Stanley, 2011; LePain and others, 2012; LePain and others, submitted). During May 2009 helicopter-assisted field studies, 19 samples of dark-colored, fine-grained rocks were collected from exposures of the Red Glacier Formation of the Tuxedni Group near Red Glacier, about 70 km west of Ninilchik on the eastern flank of Iliamna Volcano (figs. 1 and 3). The rock samples were submitted to a commercial laboratory for analysis by Rock-Eval pyrolysis and to the U.S. Geological Survey organic geochemical laboratory in Denver, Colorado, for analysis of vitrinite reflectance. The results show that values of vitrinite reflectance (percent Ro) in our samples average about 2 percent, much higher than the oil window range of 0.6–1.3 percent (Johnsson and others, 1993). The high vitrinite reflectance values indicate that the rock samples experienced significant heating and furthermore suggest that these rocks may have generated oil and gas in the past but no longer have any hydrocarbon source potential. The high thermal maturity of the rock samples may have resulted from (1) the thermaleffects of igneous activity (including intrusion by igneous rocks), (2) deep burial beneath Jurassic, Cretaceous, and Tertiary strata that were subsequently removed by uplift and erosion, or (3) the combined effects of igneous activity and burial.

  17. Pooh Bear rock and Mermaid Dune

    NASA Technical Reports Server (NTRS)

    1997-01-01

    One of the two forward cameras aboard Sojourner imaged this area of Martian terrain on Sol 26. The large rock dubbed 'Pooh Bear' is at far left, and stands between four and five inches high. Mermaid Dune is the smooth area stretching horizontally across the top quarter of the image. The Alpha Proton X-Ray Spectrometer (APXS) instrument aboard Sojourner will be deployed on Mermaid Dune, and the rover will later use its cleated wheels to dig into it.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages and Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

  18. New Constraints on the Rock Size Distribution on the Moon from Diviner Infrared Measurements

    NASA Astrophysics Data System (ADS)

    Elder, C. M.; Hayne, P. O.; Piqueux, S.; Bandfield, J. L.; Ghent, R. R.; Williams, J. P.; Paige, D. A.

    2015-12-01

    Most of the Moon's surface is covered by fine-grained regolith produced by impacts, but rocks of various sizes are also present. Rock abundances can be used to distinguish different surface units and quantify the ages of craters [1,2]. Furthermore, the size distribution of a population of rocks reflects the process by which they were formed and fragmented [3]. Knowing the distribution of rock sizes on the Moon can improve our understanding of regolith generation, evolution, and distribution, can be used to select landing sites, and can provide insight into the processes that have shaped the lunar surface. The high thermal inertia of rocks compared to fine-grained regolith leads to multiple temperatures within the field of view of nighttime multispectral data returned from the Lunar Reconnaissance Orbiter (LRO) Diviner thermal radiometer. This data has been used to map the rock abundance across the lunar surface [1]. However, the derived rock abundance is not constant over the course of the lunar night; small rocks cool faster than large rocks and eventually become indistinguishable from regolith using Diviner data. Thus the detectable rock abundance will decrease over the course of the lunar night. Here we use this change in measured rock abundance with time to constrain the size distribution of rock fragments, and map its variation across the lunar surface. We will show results from this study and discuss the implications for the geologic processes shaping the lunar surface. [1] Bandfield J. L. et al. (2011) JGR, 116, E00H02. [2] Ghent R. R. et al. (2014) Geology, 42, no. 12, 1059-1062. [3] Hartmann W. K. (1969) Icarus, 10, 201-213. Part of this work was performed at the Jet Propulsion Laboratory, California Institute of Technology under contract with the National Aeronautics and Space Administration.

  19. Multiphysics processes in partially saturated fractured rock: Experiments and models from Yucca Mountain

    NASA Astrophysics Data System (ADS)

    Rutqvist, Jonny; Tsang, Chin-Fu

    2012-09-01

    The site investigations at Yucca Mountain, Nevada, have provided us with an outstanding data set, one that has significantly advanced our knowledge of multiphysics processes in partially saturated fractured geological media. Such advancement was made possible, foremost, by substantial investments in multiyear field experiments that enabled the study of thermally driven multiphysics and testing of numerical models at a large spatial scale. The development of coupled-process models within the project have resulted in a number of new, advanced multiphysics numerical models that are today applied over a wide range of geoscientific research and geoengineering applications. Using such models, the potential impact of thermal-hydrological-mechanical (THM) multiphysics processes over the long-term (e.g., 10,000 years) could be predicted and bounded with some degree of confidence. The fact that the rock mass at Yucca Mountain is intensively fractured enabled continuum models to be used, although discontinuum models were also applied and are better suited for analyzing some issues, especially those related to predictions of rockfall within open excavations. The work showed that in situ tests (rather than small-scale laboratory experiments alone) are essential for determining appropriate input parameters for multiphysics models of fractured rocks, especially related to parameters defining how permeability might evolve under changing stress and temperature. A significant laboratory test program at Yucca Mountain also made important contributions to the field of rock mechanics, showing a unique relation between porosity and mechanical properties, a time dependency of strength that is significant for long-term excavation stability, a decreasing rock strength with sample size using very large core experiments, and a strong temperature dependency of the thermal expansion coefficient for temperatures up to 200°C. The analysis of in situ heater experiments showed that fracture

  20. Laboratory characterization and astrophysical detection of vibrationally excited states of vinyl cyanide in Orion-KL

    NASA Astrophysics Data System (ADS)

    López, A.; Tercero, B.; Kisiel, Z.; Daly, A. M.; Bermúdez, C.; Calcutt, H.; Marcelino, N.; Viti, S.; Drouin, B. J.; Medvedev, I. R.; Neese, C. F.; Pszczółkowski, L.; Alonso, J. L.; Cernicharo, J.

    2014-12-01

    Context. We perform a laboratory characterization in the 18-1893 GHz range and astronomical detection between 80-280 GHz in Orion-KL with IRAM-30 m of CH2CHCN (vinyl cyanide) in its ground and vibrationally excited states. Aims: Our aim is to improve the understanding of rotational spectra of vibrationally excited vinyl cyanide with new laboratory data and analysis. The laboratory results allow searching for these excited state transitions in the Orion-KL line survey. Furthermore, rotational lines of CH2CHCN contribute to the understanding of the physical and chemical properties of the cloud. Methods: Laboratory measurements of CH2CHCN made on several different frequency-modulated spectrometers were combined into a single broadband 50-1900 GHz spectrum and its assignment was confirmed by Stark modulation spectra recorded in the 18-40 GHz region and by ab-initio anharmonic force field calculations. For analyzing the emission lines of vinyl cyanide detected in Orion-KL we used the excitation and radiative transfer code (MADEX) at LTE conditions. Results: Detailed characterization of laboratory spectra of CH2CHCN in nine different excited vibrational states: ν11 = 1, ν15 = 1, ν11 = 2, ν10 = 1 ⇔ (ν11 = 1,ν15 = 1), ν11 = 3/ν15 = 2/ν14 = 1, (ν11 = 1,ν10 = 1) ⇔ (ν11 = 2,ν15 = 1), ν9 = 1, (ν11 = 1,ν15 = 2) ⇔ (ν10 = 1,ν15 = 1) ⇔ (ν11 = 1,ν14 = 1), and ν11 = 4 are determined, as well as the detection of transitions in the ν11 = 2 and ν11 = 3 states for the first time in Orion-KL and of those in the ν10 = 1 ⇔ (ν11 = 1,ν15 = 1) dyad of states for the first time in space. The rotational transitions of the ground state of this molecule emerge from four cloud components of hot core nature, which trace the physical and chemical conditions of high mass star forming regions in the Orion-KL Nebula. The lowest energy vibrationally excited states of vinyl cyanide, such as ν11 = 1 (at 328.5 K), ν15 = 1 (at 478.6 K), ν11 = 2 (at 657.8 K), the ν10

  1. Felsenkeller shallow-underground accelerator laboratory for nuclear astrophysics

    NASA Astrophysics Data System (ADS)

    Bemmerer, D.; Cowan, T. E.; Gohl, S.; Ilgner, C.; Junghans, A. R.; Reinhardt, T. P.; Rimarzig, B.; Reinicke, S.; Röder, M.; Schmidt, K.; Schwengner, R.; Stöckel, K.; Szücs, T.; Takács, M.; Wagner, A.; Wagner, L.; Zuber, K.

    2015-05-01

    Favored by the low background in underground laboratories, low-background accelerator-based experiments are an important tool to study nuclear reactions involving stable charged particles. This technique has been used for many years with great success at the 0.4 MV LUNA accelerator in the Gran Sasso laboratory in Italy, proteced from cosmic rays by 1400 m of rock. However, the nuclear reactions of helium and carbon burning and the neutron source reactions for the astrophysical s-process require higher beam energies than those available at LUNA. Also the study of solar fusion reactions necessitates new data at higher energies. As a result, in the present NuPECC long range plan for nuclear physics in Europe, the installation of one or more higher-energy underground accelerators is strongly recommended. An intercomparison exercise has been carried out using the same HPGe detector in a typical nuclear astrophysics setup at several sites, including the Dresden Felsenkeller underground laboratory. It was found that its rock overburden of 45m rock, together with an active veto against the remaining muon flux, reduces the background to a level that is similar to the deep underground scenario. Based on this finding, a used 5 MV pelletron tandem with 250 μA upcharge current and external sputter ion source has been obtained and transported to Dresden. Work on an additional radio-frequency ion source on the high voltage terminal is underway. The project is now fully funded. The installation of the accelerator in the Felsenkeller is expected for the near future. The status of the project and the planned access possibilities for external users will be reported.

  2. Seed dormancy and persistent sediment seed banks of ephemeral freshwater rock pools in the Australian monsoon tropics.

    PubMed

    Cross, Adam T; Turner, Shane R; Renton, Michael; Baskin, Jerry M; Dixon, Kingsley W; Merritt, David J

    2015-04-01

    Rock pools are small, geologically stable freshwater ecosystems that are both hydrologically and biologically isolated. They harbour high levels of plant endemism and experience environmental unpredictability driven by the presence of water over variable temporal scales. This study examined the hypothesis that the sediment seed bank in monsoon tropical freshwater rock pools would persist through one or more periods of desiccation, with seed dormancy regulating germination timing in response to rock pool inundation and drying events. Seeds were collected from seven dominant rock pool species, and germination biology and seed dormancy were assessed under laboratory conditions in response to light, temperature and germination stimulators (gibberellic acid, karrikinolide and ethylene). Field surveys of seedling emergence from freshwater rock pools in the Kimberley region of Western Australia were undertaken, and sediment samples were collected from 41 vegetated rock pools. Seedling emergence and seed bank persistence in response to multiple wetting and drying cycles were determined. The sediment seed bank of individual rock pools was large (13 824 ± 307 to 218 320 ± 42 412 seeds m(-2) for the five species investigated) and spatially variable. Seedling density for these same species in the field ranged from 13 696 to 87 232 seedlings m(-2). Seeds of rock pool taxa were physiologically dormant, with germination promoted by after-ripening and exposure to ethylene or karrikinolide. Patterns of seedling emergence varied between species and were finely tuned to seasonal temperature and moisture conditions, with the proportions of emergent seedlings differing between species through multiple inundation events. A viable seed bank persisted after ten consecutive laboratory inundation events, and seeds retained viability in dry sediments for at least 3 years. The persistent seed bank in freshwater rock pools is likely to provide resilience to plant

  3. New approaches in the indirect quantification of thermal rock properties in sedimentary basins: the well-log perspective

    NASA Astrophysics Data System (ADS)

    Fuchs, Sven; Balling, Niels; Förster, Andrea

    2016-04-01

    Numerical temperature models generated for geodynamic studies as well as for geothermal energy solutions heavily depend on rock thermal properties. Best practice for the determination of those parameters is the measurement of rock samples in the laboratory. Given the necessity to enlarge databases of subsurface rock parameters beyond drill core measurements an approach for the indirect determination of these parameters is developed, for rocks as well a for geological formations. We present new and universally applicable prediction equations for thermal conductivity, thermal diffusivity and specific heat capacity in sedimentary rocks derived from data provided by standard geophysical well logs. The approach is based on a data set of synthetic sedimentary rocks (clastic rocks, carbonates and evaporates) composed of mineral assemblages with variable contents of 15 major rock-forming minerals and porosities varying between 0 and 30%. Petrophysical properties are assigned to both the rock-forming minerals and the pore-filling fluids. Using multivariate statistics, relationships then were explored between each thermal property and well-logged petrophysical parameters (density, sonic interval transit time, hydrogen index, volume fraction of shale and photoelectric absorption index) on a regression sub set of data (70% of data) (Fuchs et al., 2015). Prediction quality was quantified on the remaining test sub set (30% of data). The combination of three to five well-log parameters results in predictions on the order of <15% for thermal conductivity and thermal diffusivity, and of <10% for specific heat capacity. Comparison of predicted and benchmark laboratory thermal conductivity from deep boreholes of the Norwegian-Danish Basin, the North German Basin, and the Molasse Basin results in 3 to 5% larger uncertainties with regard to the test data set. With regard to temperature models, the use of calculated TC borehole profiles approximate measured temperature logs with an

  4. Forensic Excavation of Rock Masses: A Technique to Investigate Discontinuity Persistence

    NASA Astrophysics Data System (ADS)

    Shang, J.; Hencher, S. R.; West, L. J.; Handley, K.

    2017-11-01

    True persistence of rock discontinuities (areas with insignificant tensile strength) is an important factor controlling the engineering behaviour of fractured rock masses, but is extremely difficult to quantify using current geological survey methodologies, even where there is good rock exposure. Trace length as measured in the field or using remote measurement devices is actually only broadly indicative of persistence for rock engineering practice and numerical modelling. Visible traces of discontinuities are treated as if they were open fractures within rock mass classifications, despite many such traces being non-persistent and actually retaining considerable strength. The common assumption of 100% persistence, based on trace length, is generally extremely conservative in terms of strength and stiffness, but not always so and may lead to a wrong prediction of failure mechanism or of excavatability. Assuming full persistence would give hopelessly incorrect predictions of hydraulic conductivity. A new technique termed forensic excavation of rock masses is introduced, as a procedure for directly investigating discontinuity persistence. This technique involves non-explosive excavation of rock masses by injecting an expansive chemical splitter along incipient discontinuities. On expansion, the splitter causes the incipient traces to open as true joints. Experiments are described in which near-planar rock discontinuities, through siltstone and sandstone, were opened up by injecting the splitter into holes drilled along the lines of visible traces of the discontinuities in the laboratory and in the field. Once exposed the surfaces were examined to investigate the pre-existing persistence characteristics of the incipient discontinuities. One conclusion from this study is that visible trace length of a discontinuity can be a poor indicator of true persistence (defined for a fracture area with negligible tensile strength). An observation from this series of experiments

  5. Interannual Variability and Trends of CH4, CO and OH Using the Computationally-Efficient CH4-CO-OH (ECCOH) Module

    NASA Technical Reports Server (NTRS)

    Elshorbany, Yasin F.; Duncan, Bryan N.; Strode, Sarah A.; Wang, James S.; Kouatchou, Jules

    2015-01-01

    Methane (CH4) is the second most important anthropogenic greenhouse gas (GHG). Its 100-year global warming potential (GWP) is 34 times larger than that for carbon dioxide. The 100-year integrated GWPof CH4 is sensitive to changes in hydroxyl radical (OH) levels.Oxidation of CH4 and carbon monoxide (CO) by OH is the main loss process, thus affecting the oxidizing capacity of the atmosphere and contributing to the global ozone background. Limitations of using archived, monthly OH fields for studies of methane's and COs evolution are that feedbacks of the CH4-CO-OH system on methane, CO and OH are not captured. In this study, we employ the computationally Efficient CH4-CO-OH (ECCOH) module (Elshorbany et al., 2015) to investigate the nonlinear feedbacks of the CH4-CO-OH system on the interannual variability and trends of the CH4, CO, OH system.

  6. Studies of electrical properties of low-resistivity sandstones based on digital rock technology

    NASA Astrophysics Data System (ADS)

    Yan, Weichao; Sun, Jianmeng; Zhang, Jinyan; Yuan, Weiguo; Zhang, Li; Cui, Likai; Dong, Huaimin

    2018-02-01

    Electrical properties are important parameters to quantitatively calculate water saturation in oil and gas reservoirs by well logging interpretation. It is usual that oil layers show high resistivity responses, while water layers show low-resistivity responses. However, there are low-resistivity oil zones that exist in many oilfields around the world, leading to difficulties for reservoir evaluation. In our research, we used digital rock technology to study different internal and external factors to account for low rock resistivity responses in oil layers. We first constructed three-dimensional digital rock models with five components based on micro-computed tomography technology and x-ray diffraction experimental results, and then oil and water distributions in pores were determined by the pore morphology method. When the resistivity of each component was assigned, rock resistivities were calculated by using the finite element method. We collected 20 sandstone samples to prove the effectiveness of our numerical simulation methods. Based on the control variate method, we studied the effects of different factors on the resistivity indexes and rock resistivities. After sensitivity analyses, we found the main factors which caused low rock resistivities in oil layers. For unfractured rocks, influential factors arranged in descending order of importance were porosity, clay content, temperature, water salinity, heavy mineral, clay type and wettability. In addition, we found that the resistivity index could not provide enough information to identify a low-resistivity oil zone by using laboratory rock-electric experimental results. These results can not only expand our understandings of the electrical properties of low-resistivity rocks from oil layers, but also help identify low-resistivity oil zones better.

  7. Inverse Modeling of Surface CH4 and δ13C-CH4 Measurements to Understand Recent Trends in Global Methane Emissions

    NASA Astrophysics Data System (ADS)

    Karmakar, S.; Butenhoff, C. L.; Rice, A. L.; Lofdahl, D. B.; Khalil, A. K.

    2016-12-01

    Methane (CH4) is the second most important greenhouse gas with a radiative forcing of 0.97 W/m2 including both direct and indirect effects and a global warming potential of 28 over a 100-year time horizon. Unlike CO2 whose rate of growth in the atmosphere has remained positive and increased in recent decades, the behavior of atmospheric methane is considerably more complex and is much less understood on account of the spatiotemporal variability of its emissions which include biogenic (e.g. wetlands, ruminants, rice agriculture), thermogenic (fossil fuels), and pyrogenic (i.e. biomass burning) sources. After sustained growth during most of the 20th century, the CH4 growth rate declined falling from 15 ppbv/yr during the 1980s to 6 ppbv/yr in the 1990s to near-zero and even negative values in the early 2000s. With some surprise however, the growth rate rebounded in 2007 and has been on average 6 ppbv/yr during the past 10 years. During this same period the 13CH4/12CH4 ratio of atmospheric CH4 also declined suggesting the recent CH4 growth was caused by an increase in 13CH4-depleted biogenic emissions. Here, we provide additional insight into the recent behavior of atmospheric methane by performing a global three-dimensional Bayesian inversion of surface CH4 and 13CH4/12CH4 ratios over the period 1985-2015 using NOAA Global Monitoring Division (GMD) CH4 measurements and the GEOS-Chem chemical-transport model (CTM) at a horizontal grid resolution of 2ox2.5o. The use of the 3-D model allows us to exploit spatial patterns in the global CH4 and 13CH4/12CH4 fields that provide additional constraints on the retrieval of the time-dependent CH4 fluxes. This work follows up on our previous CH4 inversion where we used a 4ox5o horizontal grid for GEOS-Chem to retrieve fluxes from 1985 to 2009. At higher resolution more information is extracted from the observations due to improved model skill and a smaller number of stations aggregated within model grid cells. This increases the

  8. Rocks Can Wow? Yes, Rocks Can Wow!

    ERIC Educational Resources Information Center

    Hardman, Sally; Luke, Sue

    2016-01-01

    Rocks and fossils appear in the National Curriculum of England science programmes of study for children in year 3 (ages 7-8). A frequently asked question is "How do you make the classification of rocks engaging?" In response to this request from a school, a set of interactive activities was designed and organised by tutors and students…

  9. Thermal decomposition and oxidation of CH3OH.

    PubMed

    Lee, Pei-Fang; Matsui, Hiroyuki; Xu, Ding-Wei; Wang, Niann-Shiah

    2013-01-24

    Thermal decomposition of CH(3)OH diluted in Ar has been studied by monitoring H atoms behind reflected shock waves of 100 ppm CH(3)OH + Ar. The total decomposition rate k(1) for CH(3)OH + M → products obtained in this study is expressed as, ln(k(1)/cm(3) molecule(-1) s(-1)) = -(14.81 ± 1.22) - (38.86 ± 1.82) × 10(3)/T, over 1359-1644 K. The present result on k(1) is indicated to be substantially smaller than the extrapolation of the most of the previous experimental data but consistent with the published theoretical results [Faraday Discuss. 2002, 119, 191-205 and J. Phys. Chem. A 2007, 111, 3932-3950]. Oxidation of CH(3)OH has been studied also by monitoring H atoms behind shock waves of (0.35-100) ppm CH(3)OH + (100-400) ppm O(2) + Ar. For the low concentration CH(3)OH (below 10 ppm) + O(2) mixtures, the initial concentration of CH(3)OH is evaluated by comparing evolutions of H atoms in the same concentration of CH(3)OH with addition of 300 ppm H(2) diluted in Ar. The branching fraction for CH(3)OH + Ar → (1)CH(2) + H(2)O + Ar has been quantitatively evaluated from this comparative measurements with using recent experimental result on the yield of H atoms in the reaction of (1,3)CH(2) + O(2) [J. Phys. Chem. A 2012, 116, 9245-9254]; i.e., the branching fraction for the above reaction is evaluated as, φ(1a) = 0.20 ± 0.04 at T = 1880-2050 K, in the 1.3 and 3.5 ppm CH(3)OH + 100 ppm O(2) samples. An extended reaction mechanism for the pyrolysis and oxidation of CH(3)OH is constructed based on the results of the present study combined with the oxidation mechanism of natural gas [GRI-Mech 3.0]; evolution of H atoms can be predicted very well with this new reaction scheme over a wide concentration range for the pyrolysis (0.36-100 ppm CH(3)OH), and oxidation (0.36-100 ppm CH(3)OH + 100/400 ppm O(2)) of methanol.

  10. Amino acids and hydrocarbons approximately 3,800-Myr old in the Isua rocks, southwestern Greenland

    NASA Technical Reports Server (NTRS)

    Nagy, B.; Engel, M. H.; Zumberge, J. E.; Ogino, H.; Chang, S. Y.

    1981-01-01

    Results of an analysis of amino acids and hydrocarbons found in the Isua banded iron formation, which contains the oldest known rocks on earth, are discussed. Similarities are pointed out between the relative amino acid abundances of the Isua rocks and those of lichens found on their surfaces, and a lack of substantial racemization indicated by the low D/L ratios in the 3800-million year old rock samples is noted. Experimental results showing the possibility of amino acid diffusion from lichens into the rocks are presented. Comparisons of the Isua rock amino acid D/L ratios with those reported for samples from other regions indicates that none of the Isua amino acids are older than a few tens of thousands to a few hundred thousand years. Analyses of the saturated hydrocarbons of the Isua samples reveals no odd carbon number preference, which may indicate antiquity, however laboratory experiments have shown that amino acids and aromatic and saturated aliphatic hydrocarbons could not have survived the metamorphic history of the Isua rocks. The evidence presented thus suggests that the amino acids and hydrocarbons found are not of the age of the sediments.

  11. Effect of CH4 on the CO2 breakthrough pressure and permeability of partially saturated low-permeability sandstone in the Ordos Basin, China

    NASA Astrophysics Data System (ADS)

    Zhao, Yan; Yu, Qingchun

    2018-01-01

    The behavior of CO2 that coexists with CH4 and the effect of CH4 on the CO2 stream need to be deeply analyzed and studied, especially in the presence of water. Our previous studies investigated the breakthrough pressure and permeability of pure CO2 in five partially saturated low-permeability sandstone core samples from the Ordos Basin, and we concluded that rocks with a small pore size and low permeability show considerable sealing capacity even under unsaturated conditions. In this paper, we selected three of these samples for CO2-CH4 gas-mixture breakthrough experiments under various degrees of water saturation. The breakthrough experiments were performed by increasing the gas pressure step by step until breakthrough occurred. Then, the effluent gas mixture was collected for chromatographic partitioning analysis. The results indicate that CH4 significantly affects the breakthrough pressure and permeability of CO2. The presence of CH4 in the gas mixture increases the interfacial tension and, thus, the breakthrough pressure. Therefore, the injected gas mixture that contains the highest (lowest) mole fraction of CH4 results in the largest (smallest) breakthrough pressure. The permeability of the gas mixture is greater than that for pure CO2 because of CH4, and the effective permeability decreases with increased breakthrough pressure. Chromatographic partitioning of the effluent mixture gases indicates that CH4 breaks through ahead of CO2 as a result of its weaker solubility in water. Correlations are established between (1) the breakthrough pressure and water saturation, (2) the effective permeability and water saturation, (3) the breakthrough pressure and effective permeability, and (4) the mole fraction of CO2/CH4 in the effluent mixture gases and water saturation. These results deepen our understanding of the multi-phase flow behavior in the porous media under unsaturated conditions, which have implications for formulating emergency response plans for gas

  12. Bounce Rock Dimple

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This panoramic camera image shows the hole drilled by the Mars Exploration Rover Opportunity's rock abrasion tool into the rock dubbed 'Bounce' on Sol 65 of the rover's journey. The tool drilled about 7 millimeters (0.3 inches) into the rock and generated small piles of 'tailings' or rock dust around the central hole, which is about 4.5 centimeters (1.7 inches) across. The image from sol 66 of the mission was acquired using the panoramic camera's 430 nanometer filter.

  13. Spectral mixture modeling - A new analysis of rock and soil types at the Viking Lander 1 site. [on Mars

    NASA Technical Reports Server (NTRS)

    Adams, J. B.; Smith, M. O.; Johnson, P. E.

    1986-01-01

    A Viking Lander 1 image was modeled as mixtures of reflectance spectra of palagonite dust, gray andesitelike rock, and a coarse rocklike soil. The rocks are covered to varying degrees by dust but otherwise appear unweathered. Rocklike soil occurs as lag deposits in deflation zones around stones and on top of a drift and as a layer in a trench dug by the lander. This soil probably is derived from the rocks by wind abrasion and/or spallation. Dust is the major component of the soil and covers most of the surface. The dust is unrelated spectrally to the rock but is equivalent to the global-scale dust observed telescopically. A new method was developed to model a multispectral image as mixtures of end-member spectra and to compare image spectra directly with laboratory reference spectra. The method for the first time uses shade and secondary illumination effects as spectral end-members; thus the effects of topography and illumination on all scales can be isolated or removed. The image was calibrated absolutely from the laboratory spectra, in close agreement with direct calibrations. The method has broad applications to interpreting multispectral images, including satellite images.

  14. Subsoil methanogenesis as source of stem CH4 emission in upland forest trees: preferential CH4 transport via the root system?

    NASA Astrophysics Data System (ADS)

    Maier, M.; Machacova, K.; Urban, O.; Friederike, L.

    2016-12-01

    Quantifying and understanding green house gas fluxes in natural soil-plant-atmosphere systems are crucial to predicting global climate change. Wetland species or trees at waterlogged sites are known to emit large amounts of CH4. Yet upland forest soils are regarded as CH4 sinks and tree species like upland European beech (Fagus sylvatica, L.) are assumed not to emit CH4. We studied the soil-atmosphere and stem-atmosphere fluxes of CH4, and soil gas profiles at two upland beech forest sites in Central Europe. Soil was a net CH4 sink at both. Unusually there was one beech tree with substantial CH4 emissions that were higher than the CH4 sink of the soil. The soil gas profile at this tree indicated CH4 production at a soil depth >0.3 m, despite the net uptake of CH4 observed at the soil surface adjacent to the tree. Field soil assessment showed strong redoximorphic color patterns in the adjacent soil. We think that there is a transport link between the soil and stem via the root system representing a preferential transport mechanism for CH4 despite the fact that beech roots usually do not bear aerenchyma. The gas transport process , either via dissolved CH4 in the xylem water or in the root gas phase, is not yet clear. The observed CH4 stem emissions represent an important CH4flux in this ecosystem, und thus should be considered in future research. AcknowledgementThis research was financially supported by the Czech Academy of Sciences and the German Academic Exchange Service within the project "Methane (CH4) and nitrous oxide (N2O) emissions from Fagus sylvatica trees" (DAAD-15-03), National Programme for Sustainability I (LO1415) and project DFG (MA 5826/2-1). We would like to thank Marek Jakubik, Katerina Svobodova, Sinikka Paulus, Ellen Halaburt and Sally Haddad for technical support.

  15. Direct formation of (CH sub 3 ) sub 2 HSiCl from silicon and CH sub 3 Cl

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Magrini, K.A.; Falconer, J.L.; Koel, B.E.

    1989-07-13

    A Cu-catalyzed reaction procedure was found for the selective formation of dimethylchlorosilane ((CH{sub 3}){sub 2}HSiCl) from the direct reaction of CH{sub 3}Cl with solid Si. The new procedure is a two-step process. A Cu/Si sample is prepared by evaporating Cu onto clean polycrystalline Si under ultrahigh vacuum, and the Cu/Si surface is first activated by exposure to 10% HSiCl{sub 3}/CH{sub 3}Cl at 598 K. After the HSiCl{sub 3}CH{sub 3}Cl mixture is evacuated from the reactor, the activated Cu/Si surface is reacted in fresh CH{sub 3}Cl. For low surface concentrations of Cu, the partially hydrogenated silane, (CH{sub 3}){sub 2}HSiCl, is selectivelymore » produced. Trichlorosilane was also found to activate polycrystalline Si (in the absence of Cu) for production of highly chlorinated methylchlorosilanes at a much higher rate than on the Cu/Si surface but with poor selectively to (CH{sub 3}){sub 2}HSiCl. All reactions are carried out at atmospheric pressure in a reactor that is attached to an ultrahigh-vacuum chamber. This allows surface analysis of Auger electron spectroscopy, which detected SiCl{sub x} on reacted surfaces. These SiCl{sub x} sites, which appear necessary for methylchlorosilane formation, are apparently formed during activation by HSiCl{sub 3}.« less

  16. Diminishing friction of joint surfaces as initiating factor for destabilising permafrost rocks?

    NASA Astrophysics Data System (ADS)

    Funk, Daniel; Krautblatter, Michael

    2010-05-01

    Degrading alpine permafrost due to changing climate conditions causes instabilities in steep rock slopes. Due to a lack in process understanding, the hazard is still difficult to asses in terms of its timing, location, magnitude and frequency. Current research is focused on ice within joints which is considered to be the key-factor. Monitoring of permafrost-induced rock failure comprises monitoring of temperature and moisture in rock-joints. The effect of low temperatures on the strength of intact rock and its mechanical relevance for shear strength has not been considered yet. But this effect is signifcant since compressive and tensile strength is reduced by up to 50% and more when rock thaws (Mellor, 1973). We hypotheisze, that the thawing of permafrost in rocks reduces the shear strength of joints by facilitating the shearing/damaging of asperities due to the drop of the compressive/tensile strength of rock. We think, that decreasing surface friction, a neglected factor in stability analysis, is crucial for the onset of destabilisation of permafrost rocks. A potential rock slide within the permafrost zone in the Wetterstein Mountains (Zugspitze, Germany) is the basis for the data we use for the empirical joint model of Barton (1973) to estimate the peak shear strength of the shear plane. Parameters are the JRC (joint roughness coefficient), the JCS (joint compressive strength) and the residual friction angle (φr). The surface roughness is measured in the field with a profile gauge to create 2D-profiles of joint surfaces. Samples of rock were taken to the laboratory to measure compressive strength using a high-impact Schmidt-Hammer under air-dry, saturated and frozen conditions on weathered and unweathered surfaces. Plugs where cut out of the rock and sand blasted for shear tests under frozen and unfrozen conditions. Peak shear strength of frozen and unfrozen rocks will be calculated using Barton's model. First results show a mean decrease of compressive

  17. The Role of the Rock on Hydraulic Fracturing of Tight Shales

    NASA Astrophysics Data System (ADS)

    Suarez-Rivera, R.; Green, S.; Stanchits, S.; Yang, Y.

    2011-12-01

    Successful economic production of oil and gas from nano-darcy-range permeability, tight shale reservoirs, is achieved via massive hydraulic fracturing. This is so despite their limited hydrocarbon in place, on per unit rock volume basis. As a reference, consider a typical average porosity of 6% and an average hydrocarbon saturation of 50% to 75%. The importance of tight shales results from their large areal extent and vertical thickness. For example, the areal extent of the Anwar field in Saudi Arabia of 3230 square miles (and 300 ft thick), while the Marcellus shale alone is over 100,000 square miles (and 70 to 150 ft thick). The low permeability of the rock matrix, the predominantly mineralized rock fabric, and the high capillary forces to both brines and hydrocarbons, restrict the mobility of pore fluids in these reservoirs. Thus, one anticipates that fluids do not move very far within tight shales. Successful production, therefore results from maximizing the surface area of contact with the reservoir by massive hydraulic fracturing from horizontal bore holes. This was the conceptual breakthrough of the previous decade and the one that triggered the emergence of gas shales, and recently oily shales, as important economic sources of energy. It is now understood that the process can be made substantially more efficient, more sustainable, and more cost effective by understanding the rock. This will be the breakthrough of this decade. Microseismic monitoring, mass balance calculations, and laboratory experiments of hydraulic fracturing on tight shales indicate the development of fracture complexity and fracture propagation that can not be explained in detail in this layered heterogeneous media. It is now clear that in tight shales the large-scale formation fabric is responsible for fracture complexity. For example, the presence and pervasiveness of mineralized fractures, bed interfaces, lithologic contacts, and other types of discontinuities, and their orientation

  18. Internal friction Q factor measurements in lunar rocks

    NASA Technical Reports Server (NTRS)

    Tittmann, B. R.

    1978-01-01

    In order to better interpret recently reported values for the variation of seismic Q as a function of depth below the lunar surface, we have developed apparatus and made laboratory measurements of Q as a function of hydrostatic pressure, temperature and frequency. Our measurements of the Q associated with shear deformations have demonstrated that the large difference in Q between well outgassed and volatile rich rocks persists to pressures corresponding to a depth of at least 50 km. Here we report new measurements of Q as a function of temperature, on the development of techniques to measure the Q associated with extensional deformations under hydrostatic pressure, on the derivation of theoretical relations between our laboratory Q values and the attenuation coefficient of seismic waves, and on the development of a model for mechanism of adsorption.

  19. Microbial communities in carbonate rocks-from soil via groundwater to rocks.

    PubMed

    Meier, Aileen; Singh, Manu K; Kastner, Anne; Merten, Dirk; Büchel, Georg; Kothe, Erika

    2017-09-01

    Microbial communities in soil, groundwater, and rock of two sites in limestone were investigated to determine community parameters differentiating habitats in two lithostratigraphic untis. Lower Muschelkalk and Middle Muschelkalk associated soils, groundwater, and rock samples showed different, but overlapping microbial communities linked to carbon fluxes. The microbial diversities in soil were highest, groundwater revealed overlapping taxa but lower diversity, and rock samples were predominantly characterized by endospore forming bacteria and few archaea. Physiological profiles could establish a differentiation between habitats (soil, groundwater, rock). From community analyses and physiological profiles, different element cycles in limestone could be identified for the three habitats. While in soil, nitrogen cycling was identified as specific determinant, in rock methanogenesis linked carbonate rock to atmospheric methane cycles. These patterns specifically allowed for delineation of lithostratigraphic connections to physiological parameters. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Design and development of a dust dispersion chamber to quantify the dispersibility of rock dust.

    PubMed

    Perera, Inoka E; Sapko, Michael J; Harris, Marcia L; Zlochower, Isaac A; Weiss, Eric S

    2016-01-01

    Dispersible rock dust must be applied to the surfaces of entries in underground coal mines in order to inert the coal dust entrained or made airborne during an explosion and prevent propagating explosions. 30 CFR. 75.2 states that "… [rock dust particles] when wetted and dried will not cohere to form a cake which will not be dispersed into separate particles by a light blast of air …" However, a proper definition or quantification of "light blast of air" is not provided. The National Institute for Occupational Safety and Health (NIOSH) has, consequently, designed a dust dispersion chamber to conduct quantitative laboratory-scale dispersibility experiments as a screening tool for candidate rock dusts. A reproducible pulse of air is injected into the chamber and across a shallow tray of rock dust. The dust dispersed and carried downwind is monitored. The mass loss of the dust tray and the airborne dust measurements determine the relative dispersibility of the dust with respect to a Reference rock dust. This report describes the design and the methodology to evaluate the relative dispersibility of rock dusts with and without anti-caking agents. Further, the results of this study indicate that the dispersibility of rock dusts varies with particle size, type of anti-caking agent used, and with the untapped bulk density. Untreated rock dusts, when wetted and dried forming a cake that was much less dispersible than the reference rock dust used in supporting the 80% total incombustible content rule.