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Sample records for rocks etudes rmn

  1. Magnetic resonance studies of solid polymers; Etude des polymeres solides par resonance magnetique

    Energy Technology Data Exchange (ETDEWEB)

    Lenk, R [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1969-07-01

    This paper is a review of the application of nuclear magnetic resonance (NMR) to solid polymers. In the first, theoretical part, the elements of the theory of NMR, which are necessary for the study of the properties of solid polymers are discussed: the moments method, nuclear relaxation and the distribution of correlation times. In the second part the experimental results are presented. (author) [French] Cette etude est une recherche bibliographique sur l'application de la resonance magnetique nucleaire (RMN) aux polymeres solides. Dans la premiere partie theorique on discute les elements de la theorie de RMN, necessaires pour l'etude des proprietes des polymeres solides: la methode des moments, la relaxation nucleaire et la distribution des temps de correlation. La deuxieme partie presente les resultats des experiences. (auteur)

  2. Magnetic structure analyses of multiferroics RMnO3 and RMn2O5

    International Nuclear Information System (INIS)

    Arima, Taka-hisa; Kimura, Hiroyuki

    2010-01-01

    Magnetic structure of typical multiferroic materials RMnO 3 and RMn 2 O 5 (R:rare earth) has been investigated by neutron diffraction. Magnetic structure analysis using single crystal revealed that both the materials have a cycloidal magnetic structure, where ferroelectricity arises. Polarized neutron diffraction under electric field found the one-to-one correspondence between the direction of cycloidal rotation (spin chirality) and the direction of the electric polarization, evincing that the electric polarization is directly induced by the cycloidal magnetic order. (author)

  3. INTERVALOS DE INTEGRACIÓN UNIFICADOS PARA LA CARACTERIZACIÓN ESTRUCTURAL DE PETRÓLEOS, CARBONES O SUS FRACCIONES POR RMN 1H Y RMN 13C

    Directory of Open Access Journals (Sweden)

    Avella Eliseo

    2010-09-01

    Full Text Available Con base en la revisión de publicaciones, hechas entre 1972 y 2006, se evidenció que hay imprecisiones en los límites de los intervalos de integración que los autores asignan a las señales en resonancia magnética nuclear (RMN para hacer la caracterización estructural de petróleos, carbones o sus fracciones derivadas, a partir de sus espectros de hidrógeno (RMN 1H o de carbono (RMN 13C. En consecuencia, se determinaron límites unificados para la integración de los espectros RMN 1H y RMN 13C de tales muestras mediante un tratamiento estadístico aplicado a los límites de los intervalos de integración ya publicados. Con esos límites unificados se elaboraron cartas de correlación en RMN útiles para la asignación de la integral en esos intervalos, y aun en otros de menor extensión definidos en función de la intersección entre asignaciones diferentes. Además se plantearon ecuaciones necesarias para establecer la integral atribuible a fragmentos más específicos en un intento por hacer una caracterización estructural más exacta a partir de los espectros RMN de petróleos, carbones o sus fracciones derivadas.

  4. Intervalos de integración unificados para la caracterización estructural de petróleos, carbones o sus fracciones por rmn 1h y rmn 13c

    OpenAIRE

    Eliseo, Avella; Fierro, Ricardo

    2010-01-01

    Con base en la revisión de publicaciones, hechas entre 1972 y 2006, se evidenció que hay imprecisiones en los límites de los intervalos de integración que los autores asignan a las señales en resonancia magnética nuclear (RMN) para hacer la caracterización estructural de petróleos, carbones o sus fracciones derivadas, a partir de sus espectros de hidrógeno (RMN 1H) o de carbono (RMN 13C). En consecuencia, se determinaron límites unificados para la integración de los espectros RMN 1H y RMN 13C...

  5. Analysis of the Anisotropic Magnetocaloric Effect in RMn2O5 Single Crystals

    Directory of Open Access Journals (Sweden)

    Mohamed Balli

    2017-11-01

    Full Text Available Thanks to the strong magnetic anisotropy shown by the multiferroic RMn2O5 (R = magnetic rare earth compounds, a large adiabatic temperature change can be induced (around 10 K by rotating them in constant magnetic fields instead of the standard magnetization-demagnetization method. Particularly, the TbMn2O5 single crystal reveals a giant rotating magnetocaloric effect (RMCE under relatively low constant magnetic fields reachable by permanent magnets. On the other hand, the nature of R3+ ions strongly affects their RMCEs. For example, the maximum rotating adiabatic temperature change exhibited by TbMn2O5 is more than five times larger than that presented by HoMn2O5 in a constant magnetic field of 2 T. In this paper, we mainly focus on the physics behind the RMCE shown by RMn2O5 multiferroics. We particularly demonstrate that the rare earth size could play a crucial role in determining the magnetic order, and accordingly, the rotating magnetocaloric properties of RMn2O5 compounds through the modulation of exchange interactions via lattice distortions. This is a scenario that seems to be supported by Raman scattering measurements.

  6. Difusão de spins nucleares em meios porosos - uma abordagem computacional da RMN

    OpenAIRE

    Éverton Lucas-Oliveira

    2015-01-01

    A Ressonância Magnética Nuclear (RMN) é uma importante técnica empregada nas principais áreas de conhecimento, tais como, Física, Química e Medicina. Importantes trabalhos da RMN aplicada ao estudo da dinâmica de moléculas em fluidos presentes em meios porosos permitiram que esta técnica ganhasse também notoriedade na indústria do petróleo. O presente projeto é fundamentado em alguns destes trabalhos seminais, reproduzindo, através de modelos físico-computacionais, os principais efeitos físic...

  7. Ferrielectricity in DyMn2O5: A golden touchstone for multiferroicity of RMn2O5 family

    Directory of Open Access Journals (Sweden)

    J.-M. Liu

    2015-06-01

    Full Text Available The RMn2O5 manganite compounds represent one class of multiferroic family with magnetic origins, which has been receiving continuous attention in the past decade. So far, our understanding of the magnetic origins for ferroelectricity in RMn2O5 is associated with the nearly collinear antiferromagnetic structure of Mn ions, while the exchange striction induced ionic displacements are the consequence of the spin frustration competitions. While this scenario may be applied to almost all RMn2O5 members, its limitation is either clear: the temperature-dependent behaviors of electric polarization and its responses to external stimuli are seriously materials dependent. These inconsistences raise substantial concern with the state-of-the-art physics of ferroelectricity in RMn2O5. In this mini-review, we present our recent experimental results on the roles of the 4f moments from R ions which are intimately coupled with the 3d moments from Mn ions. DyMn2O5 is a golden figure for illustrating these roles. It is demonstrated that the spin structure accommodates two nearly collinear sublattices which generate respectively two ferroelectric (FE sublattices, enabling DyMn2O5 an emergent ferrielectric (FIE system rarely identified in magnetically induced FEs. The evidence is presented from several aspects, including FIE-like phenomena and magnetoelectric responses, proposed structural model, and experimental check by nonmagnetic substitutions of the 3d and 4f moments. Additional perspectives regarding possible challenges in understanding the multiferroicity of RMn2O5 as a generalized scenario are discussed.

  8. Folds and Etudes

    Science.gov (United States)

    Bean, Robert

    2007-01-01

    In this article, the author talks about "Folds" and "Etudes" which are images derived from anonymous typing exercises that he found in a used copy of "Touch Typing Made Simple". "Etudes" refers to the musical tradition of studies for a solo instrument, which is a typewriter. Typing exercises are repetitive attempts to type words and phrases…

  9. Specific heat and magnetization of RMn2(H,D)2

    International Nuclear Information System (INIS)

    Tarnawski, Z.; Kolwicz-Chodak, L.; Figiel, H.; Kim-Ngan, N.-T.H.; Havela, L.; Miliyanchuk, K.; Sechovsky, V.; Santava, E.; Sebek, J.

    2007-01-01

    The effect of hydrogen absorption on magnetic and thermodynamic properties of hydrides compounds RMn 2 (H,D) 2 (R = Y, Nd, Tb, Ho, and Er) have been investigated by performing specific heat and magnetization measurements in the temperature range of 2-320 K and in magnetic fields up to 9 T. The phase transition to the antiferromagnetic order accompanying a crystal structure transformation have been revealed by complicated-structure anomalies in specific heat and weak anomalies in magnetization

  10. Nuclear magnetic resonance at 310 MHz in a superconducting solenoid; Resonance magnetique nucleaire a 310 MHz dans un solenoide supra-conducteur

    Energy Technology Data Exchange (ETDEWEB)

    Dunand, J J [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1970-07-01

    The realisation of an NMR spectrometer with a superconducting magnet is presented in the first section. The methods to attain the best possible homogeneity of the magnetic field and to minimize the error in the spectrometer are described. The second section is devoted to the study of elastomers and nitr-oxides free radicals. A shift of the transition temperature with the magnetic field appears for the elastomers. The increasing paramagnetic shift has allowed a complete study by NMR of piperidinic and pyrrolidinic nitroxide free radicals. (author) [French] Dans la premiere partie est exposee la realisation d'un spectrometre de RMN utilisant un solenoide supraconducteur. Des solutions sont donnees pour obtenir la meilleure homogeneite possible du champ magnetique et pour minimiser les sources d'erreur apportees par le spectrometre. La deuxieme partie est consacree a l'etude d'elastomeres et de radicaux libres nitroxydes. Une variation de la temperature de transition avec le champ magnetique est mise en evidence pour les elastomeres. L'accroissement du deplacement paramagnetique a permis une etude complete par RMN des radicaux libres nitroxydes piperidiniques et pyrrolidiniques. (auteur)

  11. Effect of ionic size on the orbital ordering transition in RMnO3+δ

    NARCIS (Netherlands)

    Maris, G.; Volotchaev, V.; Palstra, T.T.M.

    2004-01-01

    We present high-temperature powder x-ray diffraction data of the orbital-order-induced structural distortion of RMnO3, with R a rare earth element. The associated phase transition takes place in a temperature interval of ≈200K in which the orbitally ordered phase and the orbitally disordered phase

  12. The pseudogap and anisotropic thermal expansion in RMn{sub 4}Al{sub 8} (R = La,Y,Lu and Sc)

    Energy Technology Data Exchange (ETDEWEB)

    Muro, Y; Nakamura, H; Kohara, T [Graduate School of Material Science, University of Hyogo, Kamigori, Ako-gun, Hyogo 678-1297 (Japan)

    2006-04-26

    The temperature dependence of the magnetic susceptibility shows a broad maximum at {approx}550 and 630 K for LuMn{sub 4}Al{sub 8} and ScMn{sub 4}Al{sub 8}, respectively, which can be interpreted as due to the presence of a pseudogap in the effective bands as in LaMn{sub 4}Al{sub 8} and YMn{sub 4}Al{sub 8}. The anisotropic thermal expansion observed for RMn{sub 4}Al{sub 8} (R = La, Y, Lu and Sc) and the sensitive volume dependence of the gap width throughout the RMn{sub 4}Al{sub 8} system suggest dominant magnetic coupling in Mn spin chains along the c axis.

  13. Nuclear magnetic resonance at 310 MHz in a superconducting solenoid; Resonance magnetique nucleaire a 310 MHz dans un solenoide supra-conducteur

    Energy Technology Data Exchange (ETDEWEB)

    Dunand, J.J. [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1970-07-01

    The realisation of an NMR spectrometer with a superconducting magnet is presented in the first section. The methods to attain the best possible homogeneity of the magnetic field and to minimize the error in the spectrometer are described. The second section is devoted to the study of elastomers and nitr-oxides free radicals. A shift of the transition temperature with the magnetic field appears for the elastomers. The increasing paramagnetic shift has allowed a complete study by NMR of piperidinic and pyrrolidinic nitroxide free radicals. (author) [French] Dans la premiere partie est exposee la realisation d'un spectrometre de RMN utilisant un solenoide supraconducteur. Des solutions sont donnees pour obtenir la meilleure homogeneite possible du champ magnetique et pour minimiser les sources d'erreur apportees par le spectrometre. La deuxieme partie est consacree a l'etude d'elastomeres et de radicaux libres nitroxydes. Une variation de la temperature de transition avec le champ magnetique est mise en evidence pour les elastomeres. L'accroissement du deplacement paramagnetique a permis une etude complete par RMN des radicaux libres nitroxydes piperidiniques et pyrrolidiniques. (auteur)

  14. 13 Facile application de la RMN du carbone-13 à l'identification et à ...

    African Journals Online (AJOL)

    AKA BOKO

    de bois [13] en utilisant l'analyse directe avec RMN du carbone-13 assistée par ordinateur sans séparation préalable ont démontré la facilité et fiabilité de cette méthode éminemment non invasive. Dans une étude antérieure, nous avons appliqué cette méthodologie dans l'analyse qualitative et quantitative des sucres.

  15. Relation between ferroelectric and antiferromagnetic order in RMn2O5

    International Nuclear Information System (INIS)

    Noda, Yukio; Kimura, Hiroyuki; Kamada, Youichi; Osawa, Toshihiro; Fukuda, Yosikazu; Ishikawa, Yoshihisa; Kobayashi, Satoru; Wakabayashi, Yusuke; Sawa, Hiroshi; Ikeda, Naoshi; Kohn, Kay

    2006-01-01

    RMn 2 O 5 (R=Y and rare earth) shows successive magnetic and ferroelectric phase transitions at about 45, 40, 39, 20 and 10K. We have reinvestigated the magnetic structure of YMn 2 O 5 at the commensurate phase (T=25K) using a single crystal four-circle diffractometer in order to discuss the mechanism of magnetoelectric interaction and the origin of ferroelectricity. We also observed the lattice modulation vectors (q L ) to compare the magnetic propagation vectors (q M ) by synchrotron X-ray diffraction. Improved magnetic structure data are compared with the theory recently proposed

  16. Synthesis RMn{sub 2}O{sub 5} (R = Gd and Sm) nano- and microstructures by a simple hydrothermal method

    Energy Technology Data Exchange (ETDEWEB)

    Zhu Gangqiang, E-mail: zgq2006@snnu.edu.cn [School of Physics and Information Technology, Shaanxi Normal University, Xi' an 710062 (China); Liu Peng [School of Physics and Information Technology, Shaanxi Normal University, Xi' an 710062 (China); Hojamberdiev, Mirabbos [Shaanxi Key Laboratory of Nano-materials and Technology, Xi' an University of Architecture and Technology, Xi' an 710055 (China); Ge Bao [School of Physics and Information Technology, Shaanxi Normal University, Xi' an 710062 (China); Liu Yun; Miao Hongyan; Tan Guoqiang [College of Materials Science and Engineering, Shaanxi University of Science and Technology, Xi' an 710021 (China)

    2009-12-15

    Single-phase RMn{sub 2}O{sub 5} (R = Gd and Sm) nano- and microstructures have been successfully synthesized via a simple hydrothermal process at 250 deg. C for 24 h using NaOH as mineralizer. X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM) and selective area electron diffraction patterns (SAED) were used to characterize the as-synthesized GdMn{sub 2}O{sub 5} and SmMn{sub 2}O{sub 5} samples. The effect of NaOH concentration and the molar ratio of Mn{sup 2+}/Mn{sup 7+} on the morphology and size of the final products was studied, and a possible formation mechanism of RMn{sub 2}O{sub 5} (R = Gd and Sm) nanoplates and nanorods under hydrothermal conditions was proposed.

  17. ETUDE DE LA DISTRIBUTION DES CATIONS ECHANGEABLES

    African Journals Online (AJOL)

    SEI Joseph

    En considérant alors le cas numérique, où l'observation du signal x (t) se résume à N valeurs échantillonnées à la période Te, la densité spectrale de puissance peut ...... "ANAFOR, une stratégie efficace d'acquisition et de traitement du signal pour la. RMN du solide", Méthodes, Applications, Perspectives, Evreux (2000).

  18. Treatment of effluent at the Saclay Centre d'Etudes Nucleaires (1960); Le traitement des effluents du Centre d'Etudes Nucleaires de Saclay (1960)

    Energy Technology Data Exchange (ETDEWEB)

    Wormser, G [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    The Centre d'Etudes Nucleaires at Saclay possesses several installations from which liquid radioactive effluent is rejected, and it has thus been found necessary to construct a station for the purification of radioactive liquids and to settle various chemical, analytical and technological problems. This report describes, in the following order: - the disposal possibilities at the Centre d'Etudes Nucleaires, Saclay, - the effluents produced at the centre, - the set-up for collecting effluent, - treatment of the effluent, - results of these treatments. (author) [French] La presence, au Centre d'Etudes Nucleaires de Saclay, de plusieurs installations susceptibles de rejeter des effluents liquides radioactifs a necessite la construction d'une station d'epuration d'eaux radioactives et la mise au point de differents problemes chimiques, analytiques et technologiques. Dans ce rapport, nous exposerons successivement: - les possibilites de rejet du Centre d'Etudes Nucleaires de Saclay, - les effluents du centre, - le dispositif de collecte des effluents, - le traitement de ces effluents, - les resultats de ces traitements. (auteur)

  19. NMR studies of the molecules dynamics to the solid-liquid interfaces: from graded porous materials to oil rocks; Etudes RMN de la dynamique des molecules aux interfaces solide-liquide: des materiaux poreux calibres aux roches petroliferes

    Energy Technology Data Exchange (ETDEWEB)

    Godefroy, S

    2001-11-01

    Low field NMR relaxation for laboratory or in-situ applications provides critical information for oil recovery such as porosity, saturation, and permeability of rocks. In addition, pore size distribution and wettability can also be obtained in some cases. The technique relies on the measurement of proton longitudinal (T{sub 1}) or transverse (T{sub 2}) nuclear relaxation times. For better predictions, the surface micro-dynamics and the chemical properties of the liquids entrapped in the pore space are important and must be characterized. It is well known that the NMR relaxation is enhanced by the paramagnetic impurities at the pore surface but many other parameters influence the relaxation time distributions. These parameters are used to derive the petrophysical properties of the rocks. We propose here an original method to probe the dynamics of water and oil at the pore surface. In the present study, we used both nuclear relaxation at 2.2 MHz and field cycling Nuclear Magnetic Relaxation Dispersion (NMRD) techniques. We applied these two techniques to different kinds of water or oil saturated macroporous media (grain packings, outcrop and reservoir rocks with SiO{sub 2} or CaCO{sub 3} surfaces). We studied the dependence of NMR relaxation on pore size, magnetic field and temperature. Varying the pore size and the surface density of paramagnetic impurities of water saturated grain packings allowed experimental evidence for the two limiting regimes of the water relaxation in pores (surface- and diffusion-limited regimes). NMRD technique (evolution of 1/T{sub 1} with the magnetic field) allowed us to probe liquid surface dynamics in water or oil fully saturated grain packing, outcrop rocks or reservoir rocks (water- and oil-wet surfaces). We evidenced a two-dimensional molecular surface diffusion and directly estimated important parameters such as correlation times, residence times and molecular self-diffusion on the surface. Finally, we proved that the temperature

  20. Desarrollo de una interfaz gráfica de usuario en entorno MATLAB para el manejo de software de segmentación de imágenes RMN

    OpenAIRE

    Cancio del Busto, Javier

    2011-01-01

    Cancio Del Busto, J. (2010). Desarrollo de una interfaz gráfica de usuario en entorno MATLAB para el manejo de software de segmentación de imágenes RMN. http://hdl.handle.net/10251/10184. Archivo delegado

  1. PENULISAN ETUDE-ETUDE MUSIK TALEMPONG UNGGAN (Sebuah Usaha Pembelajaran Musik Tradisi Berbasis Literatur

    Directory of Open Access Journals (Sweden)

    Asri MK

    2014-12-01

    Full Text Available “Talempong unggan”, a traditional music from Minangkabau community particularly in Unggan, Sumpur Kudus, Sijunjung Regency, West Sumatera Indonesia is classified into genre of “talempong duduak” (rea. Due to its special musical concept and the playing technics, this traditional music is selected as a practising course in the Karawitan Department of Indonesian Institute of Art (ISI Padang Panjang since 1993 till now. In a system of class learning with many students, Talempong Unggan definitely needs supporting methods and learning technics suitable for the course where the students can reach their maximum skills. All the melody of “talempong unggan” that has been made as a material of practice is transcribed to the system of numeric notation and rhythm motive of “gendang” and “aguang” which is written into signs and special notation. All of qualitative data is formulated into finding methods, technics and etude of learning ensamble of Talempong Unggan the traditional music that learned in Karawitan Department of ISI Padang Panjang. Key words: Talempong Unggan, Methods, Technics, Etude

  2. Etude aerodynamique d'un jet turbulent impactant une paroi concave

    Science.gov (United States)

    LeBlanc, Benoit

    Etant donne la demande croissante de temperatures elevees dans des chambres de combustion de systemes de propulsions en aerospatiale (turbomoteurs, moteur a reaction, etc.), l'interet dans le refroidissement par jets impactant s'est vu croitre. Le refroidissement des aubes de turbine permet une augmentation de temperature de combustion, ce qui se traduit en une augmentation de l'efficacite de combustion et donc une meilleure economie de carburant. Le transfert de chaleur dans les au bages est influence par les aspects aerodynamiques du refroidissement a jet, particulierement dans le cas d'ecoulements turbulents. Un manque de comprehension de l'aerodynamique a l'interieur de ces espaces confinees peut mener a des changements de transfert thermique qui sont inattendus, ce qui augmente le risque de fluage. Il est donc d'interet pour l'industrie aerospatiale et l'academie de poursuivre la recherche dans l'aerodynamique des jets turbulents impactant les parois courbes. Les jets impactant les surfaces courbes ont deja fait l'objet de nombreuses etudes. Par contre des conditions oscillatoires observees en laboratoire se sont averees difficiles a reproduire en numerique, puisque les structures d'ecoulements impactants des parois concaves sont fortement dependantes de la turbulence et des effets instationnaires. Une etude experimentale fut realisee a l'institut PPRIME a l'Universite de Poitiers afin d'observer le phenomene d'oscillation dans le jet. Une serie d'essais ont verifie les conditions d'ecoulement laminaires et turbulentes, toutefois le cout des essais experimentaux a seulement permis d'avoir un apercu du phenomene global. Une deuxieme serie d'essais fut realisee numeriquement a l'Universite de Moncton avec l'outil OpenFOAM pour des conditions d'ecoulement laminaire et bidimensionnel. Cette etude a donc comme but de poursuivre l'enquete de l'aerodynamique oscillatoire des jets impactant des parois courbes, mais pour un regime d'ecoulement transitoire, turbulent

  3. Nuclear study of Melusine; Etude nucleaire de Melusine

    Energy Technology Data Exchange (ETDEWEB)

    Cherot, J [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1959-07-01

    In this report are reviewed - with respect to starting of experiments - the main nuclear characteristics of a 20 per cent enriched uranium lattice, with light water as moderator and reflector. The reactor is to operate at 1 MW. 1) Study of various critical masses. 2) Control. Effectiveness of cadmium. Control rods and of a stainless steel regulating rod. 3) Study of the effect on reactivity of disturbances in the core center. 4) Study of xenon and samarium poisoning. 5) Temperature factor. 6) Heat exchanges in a fuel element. (author) [French] On etudie, dans ce rapport, les principales proprietes nucleaires d'un reseau a uranium enrichi (20 pour cent), dont le moderateur et le reflecteur sont l'eau legere en vue des experiences de demarrage. Ce reacteur devra fonctionner a 1 MW. 1) Etude de diverses masses critiques. 2) Controle. Efficacite des barres de controle en cadmium et d'une barre de reglage en acier inoxydable. 3) Etude de l'effet sur la reactivite de perturbation au centre du coeur. 4) Etude de l'empoisonnement xenon et samarium. 5) Coefficient de temperature. 6) Echanges thermiques dans un element. (auteur)

  4. Ab initio study of the structural, electronic, elastic and thermal properties of RMn{sub 2}Ge{sub 2} (R = Ca, Nd and Y) intermetallic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Miloud Abid, O.; Yakoubi, A. [Laboratoire d’Etudes des Matériaux et Instrumentations Expérimentales, Université Djilali Liabes de Sidi Bel-Abbes, 22000 (Algeria); Tadjer, A. [Modeling and Simulation in Materials Science Laboratory, Physics Department, University of Sidi Bel-Abbes, Sidi Bel-Abbes (Algeria); Khenata, R., E-mail: khenata_rabah@yahoo.fr [Laboratoire de Physique Quantique de la Modélisation Mathématique (LPQ3M), Université de Mascara, 29000 (Algeria); Ahmed, R. [Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, UTM Skudai, 81310 Johor (Malaysia); Murtaza, G. [Materials Modeling Laboratory, Department of Physics, Islamia College University, Peshawar (Pakistan); Bin Omran, S. [Department of Physics and Astronomy, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451 (Saudi Arabia); Azam, Sikander [New Technologies – Research Center, University of West Bohemia, Univerzitni 8, 306 14 Pilsen (Czech Republic)

    2014-12-15

    Highlights: • The calculated structural parameters of RMn{sub 2}Ge{sub 2} (R = Ca, Nd and Y) compounds are found in good agreement with the experimental data. • The structural and band structure calculation reveals that these compounds are ferromagnetic brittle metals. • The elastic and thermodynamic properties for the herein studied compounds are investigated for the first time. - Abstract: Intermetallic RMn{sub 2}Ge{sub 2} ternary compounds have attracted considerable attention from researchers in recent years because they show strong indications for novel magnetic characteristics and they have the potential to reveal the mechanism of superlattices. The study of the paramagnetic, ferromagnetic and antiferromagnetic phases affirms the strong dependence to the distance between atomic species in these compounds. In this study, we investigated the structural, elastic, electronic and thermodynamic properties of the intermetallic RMn{sub 2}Ge{sub 2} (R = Ca, Nd and Y) compounds. To carry out this study, we used the full potential (FP) linearized (L) augmented plane wave plus local orbitals (APW + lo), a scheme of calculations developed within the frame work of density functional theory (DFT). To incorporate the exchange correlation (XC) energy and corresponding potential into the total energy calculations, local density approximation (LDA) parameterized by Perdew and Wang is taken into account. Analysis of the density of states (DOS) profile illustrates the conducting nature of these intermetallic compounds; with a predominantly contribution from the R and Mn-d states. At ambient conditions, calculations for elastic constants (C{sub 11}, C{sub 12}, C{sub 13}, C{sub 44}, C{sub 33} and C{sub 66}) are also performed, which point to their brittle character. In addition, the quasi harmonic Debye model was used to predict the thermal properties, together with relative expansion coefficients and heat capacity.

  5. ETUDE - European Trade Union Distance Education.

    Science.gov (United States)

    Creanor, Linda; Walker, Steve

    2000-01-01

    Describes transnational distance learning activities among European trade union educators carried out as part of the European Trade Union Distance Education (ETUDE) project, supported by the European Commission. Highlights include the context of international trade union distance education; tutor training course; tutors' experiences; and…

  6. Study methods for the drillings around the underground nuclear explosions in the Sahara. Part 1. study of rock samples; Methodes d'etude des forages realises autour des explosions nucleaires souterraines au Sahara. Premiere partie: etude des echantillons de roche

    Energy Technology Data Exchange (ETDEWEB)

    Derlich, S [Commissariat a l' Energie Atomique, Bruyers-le-Chatel (France). Centre d' Etudes

    1969-07-01

    An examination of the mechanical effects produced on rocks by an underground nuclear explosion calls for the use of particular means of exploration which are described in this report, special attention being paid to the equipment used in connection with the French nuclear tests in the Sahara. The drilling methods used (rotary and turbo-drilling) are adapted to the particular conditions of the sampling programme, to the radioactivity and to the temperature in the region of the explosion. A study of the samples makes it possible to obtain the new characteristics of the rock and to assess the chemical and mechanical transformations which it has undergone. An examination of the core obtained from the drilling, together with a knowledge of the drilling parameters (depth of the probe, sample recovery, etc...), makes it possible to study the extent and the characteristics of the zones which have been damaged to different degrees according to their distance from the zero point: cavity, strongly powdered zone, fractured zone, chimney, zones containing high stresses leading to a particular type of fracture of the cores. The problems connected with the interpretation of the results are also presented. (author) [French] L'examen des effets mecaniques provoques par une explosion nucleaire souterraine sur la roche necessite la mise en oeuvre de moyens d'exploration particuliers dont l'expose fait l'objet de ce rapport, essentiellement pour les moyens utilises autour des essais nucleaires francais au Sahara. Les methodes de forage (rotary et turboforage) sont adaptees aux conditions particulieres dues au programme d'echantillonnage, a la radioactivite et a la temperature regnant a proximite du point de tir. L'etude des echantillons permet la determination des nouveaux caracteres de la roche et de ses transformations chimique et mecanique. L'examen des carottes et l'utilisation des parametres de forage (cotes sondeurs, recuperation des echantillons, etc...) permettent d'etudier l

  7. Criticality studies; Etudes de criticite

    Energy Technology Data Exchange (ETDEWEB)

    Breton, D; Lecorche, P; Clouet d' Orval, Ch [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    Criticality studies made at the Commissariat a l'Energie atomique deal on the one hand with experiments on plutonium and uranium solutions, on the other hand with theoretical work on the development and use of computation, methods for the resolution of problems concerning the nuclear safety of chemical and metallurgical plants. I - Since 1958 the experimental studies have dealt with homogeneous media constituted by a fissile salt dissolved in light water. Developed using the reactor Proserpine, the experiments have been carried on at Saclay on the Alecto assemblies where solutions of plutonium or of 90 p.100 - enriched uranium can be made critical. The results already obtained relate to critical masses of cylindrical tanks of diameters from 20 to 50 cm. reflected in several ways (water, concrete, etc. . ) at concentrations up to 100 g/liter. Physical measurements (spectra, reactor noises) and interaction measurements complete the results. Other experiments relating to plutonium solutions were begun in 1963, at the Valduc Center. They deal with the study of critical masses of annular vessels of external diameter 50 cm and internal diameter varying from 10 to 30 cm. These vessels can be water reflected internally, externally, or both. Two of these vessels have been studied in interaction for various geometries. Slabs of various thicknesses were also studied. II - The studies thus undertaken allowed the development of methods of computation which have been tested on several experiments. Particular use has been made of the possibilities of calculations based on transport theory and on Monte Carlo methods. All these theoretical studies are applied to the design and control of industrial plants from the point of view of safety. (authors) [French] Les etudes de criticite effectuees au CEA comportent d'une part des experiences sur des solutions de plutonium et d'uranium enrichi, d'autre part des travaux theoriques portant sur la mise au point et l'exploitation de methodes

  8. Implementing Formative Assessment in Engineering Education: The Use of the Online Assessment System Etude

    Science.gov (United States)

    Dopper, Sofia M.; Sjoer, Ellen

    2004-01-01

    This article describes the possibilities offered by the online assessment system Etude to achieve the benefits of formative assessment. In order to find out the way this works in practice, we carried out an experiment with the use of Etude for formative assessment in the course on collaborative report writing. Results show that online formative…

  9. Control para un equipo de análisis químico por RMN basado en un microprocesador de 32 bits

    OpenAIRE

    Palacio Tárrega, Víctor Manuel

    2009-01-01

    El objetivo del PFC es desarrollar el sistema de control de un equipo de análisis quimico por RMN. Las especificacions del sistema de control implican que este integre los ortos dos componentes del equipo de análisis ( procesado de señal y sistema de raiofrecuencia ) con una interfaz gráfica para el usuario.Se desarrollan dos componentes para el sistema de control, hardware y software, El hardware de control incrustado está basado en un procesador ARM de 32 bits,, y se completado con todos lo...

  10. Contribution to the study of several chemical hazards in the Centre d'Etudes Nucleaires of Fontenay-aux-Roses; Contribution a l'etude de quelques nuisances chimiques au centre d'etudes nucleaires de Fontenay-aux-Roses

    Energy Technology Data Exchange (ETDEWEB)

    Megemont, C; Grau, C [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1968-10-01

    From the checking of 2750 index cards of hazards, the study relates the distribution of the chemical hazards in the Centre d'Etudes Nucleaires of Fontenay-aux-Roses. Those concerning the greatest number of agents in the Centre are classified according to the categories corresponding to the different conditions of working. Thus, the most important are put forward. Then, the authors rapidly make a review of hazards which may have some special interest because they appear more specific of the nuclear energy or because they are the most frequently noted on the index cards of hazards. The case of the tributylphosphate is studied more precisely. (authors) [French] A partir de l'examen de 2750 fiches de nuisances, l'etude porte sur la repartition des nuisances chimiques au Centre d'Etudes Nucleaires de Fontenay-aux-Roses. Celles qui concernent le plus grand nombre d'agents du Centre sont classees selon les categories correspondant aux differentes conditions de travail. Les plus importantes d'entre elles sont ainsi mises en evidence. | Les auteurs passent ensuite en revue, rapidement, les nuisances qui peuvent presenter un interet particulier soit parce qu'elles semblent plus specifiques de l'Energie Nucleaire, soit parce qu'on les rencontre le plus frequemment sur les fiches de nuisances. Le cas du tributylphosphate est envisage de facon plus detaillee. (auteurs)

  11. Evidencias espectroscópicas de RMN de ¹H y 13C en la formación inusual de un "carbonilo inorgánico", derivado de la lactona costunólida

    OpenAIRE

    Díaz, Eduardo; Barrios, Héctor; Fuentes, Aydeé; Corona, David; Guzmán, Ángel

    2002-01-01

    El uso de la RMN de ¹H y 13C permitió determinar la estructura inusual de un "carbonilo inorgánico" derivado de la lactona dehidrocostus. 1H and 13C NMR of an unusual "inorganic carbonyl" derived from costunolide lactone are described.

  12. Double-flat-spiral magnetic structures: Theory and application to the RMn6X6 compounds

    International Nuclear Information System (INIS)

    Rosenfeld, E.V.; Mushnikov, N.V.

    2008-01-01

    We studied magnetic structure of a layered magnetic material, the lattice of which consists of magnetic layers separated by alternating non-magnetic layers (slabs) of two different types. For such structure, the exchange integrals between the nearest magnetic layers separated by different slabs may have different values, while the next-nearest neighbor exchange integral is the same for all magnetic layers. We developed a model based on three different interlayer exchange integrals. In the framework of this model we analyzed conditions of the appearance of a magnetic structure of the double-flat-spiral type and its distortion in external magnetic field. The results are most obtained in the analytical form. The model was applied to analyze the magnetic structure and magnetization process of the RMn 6 X 6 (R=Y, Sc, Lu; X=Sn, Ge) compounds with the layered crystal structure

  13. Contribution to the study of the structure and properties of silica gel (1962); Contribution a l'etude de la structure et des proprietes des gels de silice (1962)

    Energy Technology Data Exchange (ETDEWEB)

    Fraissard, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1961-04-15

    The study of the texture of two types of silica gels, xerogels and aerogels, shows that the latter evolve differently on heating. By I.R. spectrography it has been possible to establish that this is due to the existence, in these solids, of a microstructure undetectable by X-rays and which depends on the preparation conditions initially. By using both chemical (thermogravimetry, hydrolysis of diborane) and physical (I.R. spectrography and wide-band N.M.R.) methods we have been able to determine the state of the water of constitution of these gels (water molecules and hydroxyls) and to show that the density, the distribution and the mobility of the protons of this water are very different. For example, the relaxation time T{sub 1} of the protons of a xerogel is about 1 second whilst that of the protons in an aerogel is of the order of a microsecond. Finally, it has been possible by using high resolution N.M.R. to propose a mechanism for the adsorption of formic acid on two types of gel thereby explaining, with the help of previous results, the differences in specificity of these two solids in the decomposition reaction of this acid. (author) [French] L'etude de la texture de deux types de gels de silice, les xerogels et les aerogels, montre que ceux-ci evoluent differemment en fonction de la temperature. La spectrographie I.R a permis de preciser que ceci est du a l'existence, dans ces solides, d'une microstructure indecelable aux rayons X, et fonction des conditions initiales de preparation. Par des methodes chimiques (thermogravimetrie, hydrolyse du diborane) et physiques (spectrographie I.R et R.M.N. large bande), nous avons pu determiner l'etat de l'eau de constitution de ces gels (molecules d'eau et hydroxyles) et montrer que la densite, la repartition et la mobilite des protons de cette eau sont tres differentes. Ainsi le temps de relaxation T{sub 1} des protons d'un xerogel est de l'ordre de la seconde, celui des protons d'un aerogel de l'ordre de la

  14. Singing as a Therapeutic Agent, inThe Etude, 1891-1949.

    Science.gov (United States)

    Hunter

    1999-01-01

    The Etude music magazine, founded by Theodore Presser, was one of a number of popular music magazines published in the years prior to the establishment of the music therapy profession in 1950. During its publication run from 1883 to 1957, over 100 music therapy related articles appeared, including 13 on the health benefits of singing published between 1891 and 1949. Written by authors with diverse backgrounds, such as the famous Battle Creek, Michigan physician John Harvey Kellogg and Boston music critic Louis C. Elson, the articles contained consistent and adamant support regarding the health benefits of singing. The advantages described were both physical and psychological, and were recommended prophylactically for well persons and therapeutically for ill persons. Although the articles varied in perspective, from philosophical to theoretical to pedagogical, there is a consistent holistic medicine theme that appeared almost ahead of its time and no doubt linked to the push for vocal music education in that era. The importance of The Etude in promulgating ideas that helped shape the early practice of music therapy should not be underestimated. For much of its publication run The Etude was the largest music periodical in print, reaching its peak circulation of 250,000 copies per month in 1924.

  15. Instrumental performance of an etude after three methods of practice.

    Science.gov (United States)

    Vanden Ark, S

    1997-12-01

    For 80 fifth-grade students three practice conditions (mental, mental with physical simulation, and physical with singing) produced significant mean differences in instrumental performance of an etude. No significant differences were found for traditional, physical practice.

  16. Contribution a l'etude des plantes alimentaires mineures dans la ...

    African Journals Online (AJOL)

    Contribution a l'etude des plantes alimentaires mineures dans la prefecture de Dankpen (Togo). AB Kebenzikato, S Akpavi, K Batawila, K Wala, M Dourma, K Kossi-Titrikou, KS Amouzou, I Butare, H Dantsey-Barry, K Akpagana ...

  17. Underground nuclear explosions. Geological survey of the cavities; Explosions nucleaires souterraines etude geologique des cavites

    Energy Technology Data Exchange (ETDEWEB)

    Faure, J [Commissariat a l' Energie Atomique, Bruyeres-le-Chatel (France). Centre d' Etudes

    1969-07-01

    A geological survey of underground nuclear explosions makes it possible to determine the main characteristics of the cavity formed. The lower portion is spherical; the same was very likely true of the roof, which collapses in the majority of media with the exception of rock-salt. Its radius, for a given bomb size, can vary by a factor of two according to the type of rock. The lay-out of its contents depends on the characteristics of the solid and liquid products at the moment of the roof collapse; according to the medium involved, mixing of the rubble and the mud-flow occurs (granite) or does not occur (tuff and alluvia). In all media, the average physical properties can be evaluated. (author) [French] L'etude geologique d'explosions nucleaires souterraines permet de determiner les principaux caracteres de la cavite creee. Sa partie inferieure est spherique; il en etait vraisemblablement de meme de sa voute, effondree dans la plupart des milieux a l'exception du sel gemme. Son rayon, a energie d'engin egale, varie selon les roches du simple au double. La disposition de son contenu depend des caracteristiques des produits solides et liquides au moment de la chute du toit; selon le cas, il n'y a pas (tuf et alluvions) ou il y a (granite) melange des eboulis et des laves. Dans tous les milieux, les proprietes physiques moyennes peuvent etre evaluees. (auteur)

  18. IDENTIFICAÇÃO DE PRODUTOS DA OXIDAÇÃO DE ÓLEOS COMESTÍVEIS ATRAVÉS DA ESPECTROSCOPIA DE RMN DE 1H / IDENTIFICATION OF OXIDATION PRODUCTS IN EDIBLE OIL BY MEANS OF 1H NMR SPECTROSCOPY

    Directory of Open Access Journals (Sweden)

    MARINA COLZATO

    2009-11-01

    Full Text Available A espectroscopia por ressonância magnética nuclear de 1H de alta resolução (RMN de 1H é uma ferramenta útil para monitorar os produtos de oxidação em óleos comestíveis. O método é rápido, relativamente simples e preciso, permitindo o acompanhamento e a caracterização da formação de produtos primários de oxidação, como os hidroperóxidos e os dienos conjugados. Neste trabalho, óleos de canola, azeite de oliva e de macadâmia foram objetos de oxidação acelerada por 30 dias e os produtos de oxidação avaliados por RMN de 1H. Os resultados indicaram uma maior estabilidade (resistência ao estresse térmico, para o óleo de oliva > macadâmia > canola, respectivamente.

  19. A study of the conformation and stability of nitroxide free radicals; Etude de la conformation et de la stabilite de radicaux libres nitroxydes

    Energy Technology Data Exchange (ETDEWEB)

    Briere, R [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1969-03-01

    les constantes de couplage des protons situes en {gamma} de l'azote ont une dependance spatiale tres marquee au meme titre que les protons situes en {beta}, ce que les etudes anterieures n'avaient pu preciser. Une analyse conformationnelle est effectuee par RMN a 310 MHz, en temperature variable. La synthese du di-t-butyl nitroxyde marque au carbone 13 en position {alpha} du groupement nitroxyde a permis de determiner avec certitude la constante d'interaction hyperfine electron carbone 13 quaternaire, grandeur qui n'avait pas ete mesuree jusqu'alors. Les constantes de couplage mesurees dans les radicaux piperidiniques tetramethyles en 2,2,6,6 ont pu etre ensuite attribuees a des carbones 13 situes en {beta} de l'azote, et leur variation a pu etre reliee a la conformation des cycles. C'est l'objet de la seconde partie. Dans un dernier chapitre, l'etude cinetique d'un radical nitroxyde instable, ayant un hydrogene en {beta}, met en evidence une decomposition bimoleculaire qui met en jeu la rupture de la liaison C-H; ceci est demontre par effet isotopique primaire. On peut conclure de cette etude qu'un nitroxyde est stable lorsque les differents groupes attaches a l'atome d'azote ne peuvent provoquer une decomposition du radical, soit intramoleculairement, si la geometrie de la molecule le permet, soit intermoleculairement par dimerisation sur un autre centre d'une molecule voisine, conduisant ainsi a une fragmentation ou a une disproportionation. (auteur)

  20. Study of the retention of fission products by a few common minerals. Application to the treatment of medium activity effluents (1962); Etude de la retention des produits de fission par quelques mineraux usuels. Application aux traitements d'effluents de moyenne activite specifique (1962)

    Energy Technology Data Exchange (ETDEWEB)

    Auchapt, J M [Commissariat a l' Energie Atomique, Centre de Production de Plutonium, Marcoule (France). Centre d' Etudes Nucleaires

    1962-07-01

    The conditions in which strontium is fixed on calcite (the object of the Geneva report P/395 - USA - 1958) are more closely studied and the work is extended to five fission products present in the effluents, and to 17 common rocks and minerals. Although as it turns out this fixation is not suitable as a method of treating the S.T.E. effluents (i.e. those from the Effluent Treatment plant at Marcoule), the study shows that all the crystals considered are strongly contaminated by simple contact with the effluents. (author) [French] Les conditions de fixation du strontium sur la calcite (objet du rapport de Geneve P/395 - USA - 1958) sont approfondies et l'etude est etendue aux cinq produits de fission presents dans les effluents et a 17 roches et minerais courants. Bien qu'en definitive cette fixation se revele inutilisable comme procede de traitement d'effluents S.T.E. (Station de Traitement des Effluents, Marcoule), l'etude montre que tous les cristaux consideres se contaminent fortement par simple contact avec les effluents. (auteur)

  1. DETERMINACIÓN RÁPIDA Y PRECISA DEL CONTENIDO DE HIDRÓGENO EN MEZCLAS DE HIDROCARBUROS POR RMN 1H

    Directory of Open Access Journals (Sweden)

    Eliseo Avella

    2011-12-01

    Full Text Available Se presentan y discuten resultados de ladeterminación de hidrógeno en mezclasde hidrocarburos y de fracciones pesadasde petróleo por integración de las señalesen sus espectros RMN 1H de alta resolución.Los resultados muestran la posibilidadde cuantificar de manera rápida yprecisa el hidrógeno en 37 fragmentosestructurales, además del hidrógeno totalen la muestra, mediante aplicación deintervalos de integración unificados. Adiferencia de los métodos publicados enla literatura, la determinación de hidrógenoes posible con menor cantidad demuestra en disolución, con corto tiempode reciclado, d1, sin ajustes estrictos detemperatura ni adición de agente de relajacióno uso de algún estándar de cuantificaciónexterno.

  2. Les écoulements par RMN à gradient pulsé Pulsed Gradient Nmr Techniques for Studying Flows

    Directory of Open Access Journals (Sweden)

    Lebon L.

    2006-12-01

    Full Text Available Nous présentons ici les techniques de RMN à gradient pulsé qui permettent d'étudier les écoulements multiphasiques en canalisation ou en milieu poreux. Les principaux avantages sont de pouvoir travailler sur des milieux non transparents et d'accéder à des échelles de longueurs faibles. On montre qu'il est possible d'obtenir des informations locales sur l'écoulement, telles que le profil de vitesse et ses fluctuations dans les écoulements diphasiques, ou les cartes de distribution des probabilités de déplacement dans des échantillons poreux hétérogènes. Pulsed gradient NMR techniques are presented here. They allow the study of multiphase flow in pipes as well as porous media. The main advantages are the possibilities of studying non transparent media at small length scales. We show that it is possible to obtain local information on the fluid flow, such as velocity profiles in two phase systems, or maps of distribution of displacement probabilities in heterogeneous porous media.

  3. English Department Reforms at the Hautes Etudes Commerciales: Entering the Nineties.

    Science.gov (United States)

    Shanahan, Daniel

    1993-01-01

    Discusses the reforms made in the fall of 1990 in the English department at the Ecole Hautes Etudes Commerciales (Paris, France), which were based on the basis of a combination of literature-culture and second- and foreign-language acquisition pedagogical biases. (four references) (VWL)

  4. 98 Etude Comparative du Systeme Phonematique et Tonal des ...

    African Journals Online (AJOL)

    98. Etude Comparative du Systeme Phonematique et Tonal des. Deux Parlers: Le Yoruba du Nigeria et L'itsa Parle en. Republique du Benin. Ajani Akinwumi Lateef et Ayuba G. Ajibabi http://dx.doi./org/10.4314/ujah.v18i3.5. Résume. En ce début de l'époque ou la mondialisation et la coexistence des peuples dans le ...

  5. Autoradiography in Studying the Alteration of Rocks; L'Autoradiographie dans l'Etude de l'Alteration des Roches

    Energy Technology Data Exchange (ETDEWEB)

    Leveque, P.; Vigneaux, M. [Institut de Geologie du Bassin d' Aquitaine, Faculte des Sciences de l' Universite de Bordeaux (France)

    1967-06-15

    The alteration of rocks intended for use as the foundations of large-scale civil-engineering projects, for building construction and for rock piling has been studied and numerous tests carried out; some of these tests have been standardized in varying degrees. The conventional method of autoradiography has been used to develop one of the processes for estimating alteration due, in particular, to thermal shocks. By using {sup 35}S and {sup 32}P, the authors were able to follow the progressive alteration of different rocks in the form of microfissurations. This process is considerably more accurate than that based solely on utilization of the characteristics of rocks in normal or polarized light. In addition, it permits absolute comparison of the initial microfissuration conditions of the sample and the microfissuration found after an increasing number of thermal shock cycles. The results of the process are given in the paper. (author) [French] L'alterabilite des roches destinees, soit a des fondations de grands travaux de genie civil, soit a la construction d'immeubles, soit enfin a l'etablissement d'enrochements, a fait l'objet de nombreux essais dont certains ont ete normalises, ou tout au moins ont subi un debut de normalisation. Un des procedes de determination du processus d'alteration du notamment aux chocs thermiques a ete mis au point a partir de la methode classique d'autoradiographie. L'utilisation de {sup 35}S et de {sup 32}P a permis de suivre la progression de l'alteration par microfissuration dans des roches diverses. Ce procede est notablement plus precis que celui qui est fonde sur la seule utilisation des caracteristiques des roches en lumiere naturelle ou polarisee. De plus, il permet la comparaison en valeur absolue de l'etat de microfissuration initial de l'echantillon avec la microfissuration obtenue apres un nombre croissant de cycles de chocs thermiques. Les resultats obtenus grace a ce procede sont donnes dans le memoire. (author)

  6. Generalities on the dynamic behaviour of rapid reactors. Preliminary studies on Rapsodie; Generalites sur le comportement dynamique des piles rapides. Etudes preliminaires de rapsodie

    Energy Technology Data Exchange (ETDEWEB)

    Campan, J L; Chaumont, J P; Clauzon, P P; Ghesquiere, G; Leduc, J; Schmitt, A P; Zaleski, C P [Commissariat a l' Energie Atomique, Cadarache (France). Centre d' Etudes Nucleaires

    1963-07-01

    The study of the dynamic behaviour of fast reactors may be divided into three section: 1. Stability studies around equilibrium power only the linear case was examining. S. Transient studies in the case of usual reactor operation (shut down, scram, etc.) with thermal shocks evaluation, for instance. 3. Explosion studies, for the maximum credible accidents. This report presents the status of the studies performed at the 'Physics Research Department' at Cadarache. Methods used are detailed and illustrated with the results obtained on a preliminary metallic core of the Rapsodie Reactor. (authors) [French] Le comportement dynamique des piles rapides, se presente tout naturellement sous trois aspects: 1. Etude de stabilite autour d'un regime d'equilibre (nous nous sommes bornes ici au cas lineaire). 2. Etude de regimes transitoires lors des operations normales de pile (arret, arret d'urgence, etc.) avec evaluation des chocs thermiques par exemple. 3. Etude des regimes transitoires de caractere explosif lors des accidents les plus graves possibles. Ce rapport presente l'etat des etudes a la date du 20 decembre 1961 a la Section d'Etudes de Piles Rapides a CADARACHE. Les methodes employees ont ete detaillees et illustrees a partir des resultats obtenus sur une premiere version 'combustible metallique' de Rapsodie. (auteurs)

  7. The formation of scientists and technicians at the 'Centre d'Etudes Nucleaires' at Saclay; Formation des scientifiques et des techniciens au Centre d'Etudes Nucleaires de Saclay

    Energy Technology Data Exchange (ETDEWEB)

    Debiesse, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    The considerable needs in research workers and scientists which are asked by the nuclear energy obliged the Commissariat a l'Energie atomique to deal with a particular effort to increase the quantitative and qualitative formation of scientists. Most various ways have been used. 1- A National Institute of Nuclear Sciences and Nuclear Techniques was created, by a joint decree of the Prime Minister and the Minister for National Education (june 18, 1957). This Institute of Higher Teaching (250 students) indulges in the following matters: atomic engineering, quantum mechanics, theory and technic of particle accelerators, special metallurgy, radiobiology, thermic and mechanics of fluids. 2- An associated centre of the 'Conservatoire National des Arts et Metiers' waeated (200 students) for technical assistants, drawers, etc. 3- In contribution with both electronic industry and Ministry of Work, the Centre d'Etudes Nucleaires contributes to an accelerated formation of technical assistants into Professional Centres. Conclusion: Training of scientists and research workers is one of the most important activities of the Centre d'Etudes Nucleaires de Saclay. Without losing its technical efficiency, it has supplied and varied means adapted to the various purposes that we shall reach. (author)Fren. [French] Les besoins considerables actuels et previsibles en chercheurs et scientifiques necessites par l'avevement de l'energie nucleaire imposaient au Commissariat a I'Energie atomique un effort particulier pour augmenter la formation quantitative et qualitative des scientifiques. Les moyens les plus divers ont ete mis en oeuvre: 1- Creation de l'Institut National des Sciences et Techniques Nucleaires par decret de la Presidence du Conseil et de l'Education Nationale en date du 18.6.57. Cet Institut d'Enseignement Superieur (250 etudiants) donne des cours en: genie atomique, mecanique quantique, theorie et technique des Accelerateurs de particules, metallurgie speciale, radiobiologie

  8. Symmetry, incommensurate magnetism and ferroelectricity: The case of the rare-earth manganites RMnO3

    International Nuclear Information System (INIS)

    Ribeiro, J L

    2010-01-01

    The complete irreducible co-representations of the paramagnetic space group provide a simple and direct path to explore the symmetry restrictions of magnetically driven ferroelectricity. The method consists of a straightforward generalization of the method commonly used in the case of displacive modulated systems and allows us to determine, in a simple manner, the full magnetic symmetry of a given phase originated from a given magnetic order parameter. The potential ferroic and magneto-electric properties of that phase can then be established and the exact Landau free energy expansions can be derived from general symmetry considerations. In this work, this method is applied to the case of the orthorhombic rare-earth manganites RMnO 3 . This example will allow us to stress some specific points, such as the differences between commensurate or incommensurate magnetic phases regarding the ferroic and magnetoelectric properties, the possible stabilization of ferroelectricity by a single irreducible order parameter or the possible onset of a polarization oriented parallel to the magnetic modulation. The specific example of TbMnO 3 will be considered in more detail, in order to characterize the role played by the magneto-electric effect in the mechanism for the polarization rotation induced by an external magnetic field.

  9. Valence and magnetic state of transition-metal and rare-earth ions in single-crystal multiferroics RMn{sub 2}O{sub 5} (R = Y, Bi, Eu, Gd) from X-ray photoelectron spectroscopy data

    Energy Technology Data Exchange (ETDEWEB)

    Kozakov, A.T. [Scientific-Research Institute of Physics at Southern Federal University, 194 Stachki, Rostov-na-Donu 344194 (Russian Federation); Kochur, A.G., E-mail: agk@rgups.ru [Rostov State University of Transport Communication, 2 Narodnogo Opolcheniya, Rostov-na-Donu 344038 (Russian Federation); Nikolsky, A.V.; Googlev, K.A.; Smotrakov, V.G.; Eremkin, V.V. [Scientific-Research Institute of Physics at Southern Federal University, 194 Stachki, Rostov-na-Donu 344194 (Russian Federation)

    2011-11-15

    Highlights: {yields} Single crystals RMn{sub 2}O{sub 5} (R = Y, Bi, Eu, Gd) and YMnO{sub 3} are grown. {yields} Core level XPS are measured and calculated with inclusion of temperature effect. {yields} Mn2p, Mn3s, R4s, and R4d (R = Eu, Gd) XPS are sensitive to valence and spin state. {yields} Paramagnetic moments per structural cell are estimated. - Abstract: Single crystals of orthorhombic multiferroics RMn{sub 2}O{sub 5} (R = Y, Bi, Eu, Gd), and of hexagonal manganite YMnO{sub 3} are grown. X-ray photoelectron spectra of the core levels of the Mn, Y, Bi, Eu, Gd, and O atoms in multiferroics are obtained at room temperature with the ESCALAB 250 microprobe system with monochromatization of the exciting X-ray radiation. X-ray photoelectron spectra of Mn2p, Mn3s, R4s, and R4d (R = Eu, Gd) levels are assigned based on one-configuration isolated-ion approximation calculations with taking the temperature effect into account. It is shown using the photoelectron spectroscopy methods that both Mn{sup 3+} and Mn{sup 4+} ions are present in orthorhombic multiferroics, while Eu and Gd are in trivalent state. Paramagnetic moments per structural unit are calculated and compared with those determined from our spectroscopic data and with the data from other authors.

  10. Etude de la qualité physico-chimique et biologique des eaux du ...

    African Journals Online (AJOL)

    Etude de la qualité physico-chimique et biologique des eaux du fleuve Niger à Niamey. ... le récepteur principal des rejets d'eaux usées de la ville de Niamey, capital du ... La description de ces taxons montre une variation de la structure des ...

  11. 186 Etude théorique du transport électronique par la simulation ...

    African Journals Online (AJOL)

    youness

    Choukria SAYAH et al. 186. Etude théorique du ... For that we carried out the microscopic simulations, based on the Monte. Carlo method. ... intervalles, piezoelectric as well as the interactions of alloy and on ionized impurities. ..... SAYA et al. 198. [5] - R. W. Hockney, J. W. Eastwood, "Computer simulation using particles",.

  12. 152 Etude de cas sur l'impact des amendements organiques vis-à ...

    African Journals Online (AJOL)

    john mukalay

    Etude de cas sur l'impact des amendements organiques vis-à-vis de la salinité en culture de bananier. Michel Mazinga KWEY1, Séverin Kalala BANZE2 et John Banza MUKALAY2*. 1Laboratoire des cultures in vitro, Département de phytotechnie, Faculté des sciences agronomiques,. Université de Lubumbashi, BP 1825, ...

  13. Etude comparative de la flore aux abords des cours d'eau dans les ...

    African Journals Online (AJOL)

    Etude comparative de la flore aux abords des cours d'eau dans les zones hypo et hyper endémiques d'ulcère de Buruli en Côte d'Ivoire. C. Cisse Boni, E. Ehouman, D. Soro, M.W. Kone, A. Bakayoko, F. Dembele, K. Bauthire, M Dosso ...

  14. Study of electron groupings in the Saclay linear accelerator; Etude du groupement des electrons dans l'accelerateur lineaire de Saclay

    Energy Technology Data Exchange (ETDEWEB)

    Bergere, R; Veyssiere, A; Beil, H [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1965-07-01

    The classical theory of the linear accelerator buncher does not fit the experimental measurements of the shape of the bunch of electrons performed at Saclay by the method of the energy spectrum. If the spurious effect of the mode converter at the input of the linac is taken into account the theory can fit the experimental results and also explain the variations of the phase of the bunch on the accelerating sine wave. (authors) [French] Une etude classique du groupeur en tete de l'Accelerateur Lineaire de Saclav conduit a des resultats incompatibles avec les resultats experimentaux obtenus sur le groupement des electrons par l'etude du spectre des frequences rayonnees par le faisceau d'electrons ou par l'etude des spectres en energie. Par contre si l'effet parasite du convertisseur de mode a l'entree de l'accelerateur est pris en consideration les resultats theoriques coincident bien avec les resultats experimentaux et permettent en outre d'expliquer les variations du calage en phase des paquets elementaires d'electrons. (auteurs)

  15. Water - rock interaction in different rock environments

    International Nuclear Information System (INIS)

    Lamminen, S.

    1995-01-01

    The study assesses the groundwater geochemistry and geological environment of 44 study sites for radioactive waste disposal. Initially, the study sites were divided by rock type into 5 groups: (1) acid - intermediate rocks, (2) mafic - ultramafic rocks, (3) gabbros, amphibolites and gneisses that contain calc-silicate (skarn) rocks, (4) carbonates and (5) sandstones. Separate assessments are made of acid - intermediate plutonic rocks and of a subgroup that comprises migmatites, granite and mica gneiss. These all belong to the group of acid - intermediate rocks. Within the mafic -ultramafic rock group, a subgroup that comprises mafic - ultramafic plutonic rocks, serpentinites, mafic - ultramafic volcanic rocks and volcanic - sedimentary schists is also evaluated separately. Bedrock groundwaters are classified by their concentration of total dissolved solids as fresh, brackish, saline, strongly saline and brine-class groundwaters. (75 refs., 24 figs., 3 tabs.)

  16. Cannabinoid antagonist in nanostructured lipid carriers (NLCs): design, characterization and in vivo study

    Energy Technology Data Exchange (ETDEWEB)

    Esposito, Elisabetta; Ravani, Laura [Department of Life Sciences and Biotechnology, University of Ferrara, I-44121 Ferrara (Italy); Drechsler, Markus [BIMF/Soft Matter Electron Microscopy, University of Bayreuth (Germany); Mariani, Paolo [Department of Life and Environmental Sciences and CNISM, Università Politecnica delle Marche, I-60100 Ancona (Italy); Contado, Catia [Department of Chemical and Pharmaceutical Sciences, University of Ferrara, I-44121 Ferrara (Italy); Ruokolainen, Janne [Department of Applied Physics, Aalto University, 00076 Aalto (Finland); Ratano, Patrizia; Campolongo, Patrizia [Department of Physiology and Pharmacology, Sapienza University of Rome, 00185 Roma (Italy); Trezza, Viviana [Department of Science, Roma Tre University, 00146 Roma (Italy); Nastruzzi, Claudio, E-mail: nas@unife.it [Department of Life Sciences and Biotechnology, University of Ferrara, I-44121 Ferrara (Italy); Cortesi, Rita [Department of Life Sciences and Biotechnology, University of Ferrara, I-44121 Ferrara (Italy)

    2015-03-01

    This study describes the preparation, characterization, and in vivo evaluation in rats of nanostructured lipid carriers (NLCs) encapsulating rimonabant (RMN) as prototypical cannabinoid antagonist. A study was conducted in order to optimize NLC production by melt and ultrasonication method. NLCs were prepared by alternatively adding the lipid phase into the aqueous one (direct protocol) or the aqueous phase into the lipid one (reverse protocol). RMN-NLCs have been characterized by cryogenic transmission electron microscopy (cryo-TEM), X-ray, photon correlation spectroscopy (PCS) and sedimentation field flow fractionation (SdFFF). Reverse NLCs were treated with polysorbate 80. RMN release kinetics have been determined in vitro by dialysis method. In vivo RMN biodistribution in rats was evaluated after intranasal (i.n.) administration of reverse RMN-NLC. The reverse protocol enabled to prevent the lost of lipid phase and to achieve higher RMN encapsulation efficacy (EE) with respect to the direct protocol (98% w/w versus 67% w/w). The use of different protocols did not affect NLC morphology and dimensional distribution. An in vitro dissolutive release rate of RMN was calculated. The in vivo data indicate that i.n. administration of RMN by reverse NLC treated with polysorbate 80 increased RMN concentration in the brain with respect to the drug in solution. The nanoencapsulation protocol presented here appears as an optimal strategy to improve the low solubility of cannabinoid compounds in an aqueous system suitable for in vivo administration. - Highlights: • Rimonabant (RMN) can be encapsulated in nanostructured lipid carriers (NLCs). • Nanoencapsulation improves RMN solubility in a stable physiologic aqueous formulation. • RMN is released in vitro from NLC by a controlled dissolutive release modality. • I.n. administration leads to higher RMN concentration in the brain with respect to plasma. • NLC increases RMN concentration in the brain with respect to

  17. Caracterização de nanocompósitos de poliuretano/montmorilonita organofílica por RMN de baixo campo Characterization of polyurethane/organophilic montmorilonite nanocomposites by low field NMR

    Directory of Open Access Journals (Sweden)

    Marcos Anacleto da Silva

    2012-01-01

    Full Text Available Poliuretanos são materiais poliméricos importantes e versáteis, principalmente devido a algumas de suas propriedades, como alta resistência à abrasão, resistência ao rasgo, excelente absorção de choques mecânicos, boa flexibilidade e elasticidade. No entanto, existem também algumas desvantagens, como a baixa estabilidade térmica e propriedade de barreira. Para superar essas desvantagens, têm sido produzidos nanocompósitos de poliuretano/montmorilonita organofílica. A investigação da estrutura dos nanocompósitos de poliuretano/argila tem sido realizada principalmente por difração de raios X (DRX e microscopia eletrônica de transmissão (TEM. Neste trabalho, foram estudados filmes de nanocompósitos de PU/argila organofílica obtidos por intercalação por solução. Os nanocompósitos foram caracterizados por DRX e, principalmente, por ressonância magnética nuclear de baixo campo (RMN-BC. As medidas de RMN-BC, com a determinação do tempo de relaxação spin-rede do núcleo de hidrogênio, forneceram informações ímpares e importantes sobre a dinâmica molecular desses nanocompósitos. Para validar esse estudo foram realizadas análises de difração de raios X, que confirmaram os resultados de RMN. A estabilidade térmica dos materiais também foi determinada por análise termogravimétrica em atmosfera de gás inerte, observando-se pequena melhora na estabilidade do nanocompósito quando comparado com o poliuretano.Polyurethanes are important and versatile materials, mainly due to some of their properties, such as high resistance to abrasion and tearing, excellent absorption of mechanical shocks and good flexibility and elasticity. However, they have some drawbacks as well, such as low thermal stability and barrier properties. To overcome these disadvantages, various studies have been conducted involving organophilic polyurethane/montmorillonite nanocomposites. The investigation of the structure of polyurethane

  18. Thermal Inertia of Rocks and Rock Populations

    Science.gov (United States)

    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.

  19. Neutronic study of the two french heavy water reactors; Etude neutronique des deux piles francaises a eau lourde

    Energy Technology Data Exchange (ETDEWEB)

    Horowitz, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1955-07-01

    The two french reactors - the reactor of Chatillon, named Zoe, and the reactor of Saclay - P2 - were the object of detailed neutronic studies which the main ideas are exposed in this report. These studies were mostly done by the Department of the Reactor Studies (D.E.P.). We have thus studied the distribution of neutronic fluxes; the factors influencing reactivity; the link between reactivity and divergence with the formula of Nordheim; the mean time life of neutrons; neutron spectra s of P2; the xenon effect; or the effect of the different adjustments of the plates and controls bar. (M.B.) [French] Les deux reacteurs francais - la pile de Chatillon, appelee ZOE, et la pile de Saclay, designee dans la suite par P2 - ont fait l'objet d'etudes neutroniques detaillees dont les principales sont exposees dans ce rapport. Ces etudes ont ete pour la plupart effectuees dans le cadre du Departement des Etudes de Piles (D.E.P.). Nous avons ainsi entre autre etudie la distribution du flux neutronique; les facteurs influencants la reactivite; le lien entre reactivite et divergence par la formule de Nordheim; le temps de vie moyen des neutrons; les spectres de neutrons de P2; l'effet xenon; ou encore l'effet des differents reglages des plaques et barres de controles. (M.B.)

  20. Etude de l'impact de la variation de la température sur les activités ...

    African Journals Online (AJOL)

    Etude de l'impact de la variation de la température sur les activités microbiennes : application à une population de Listeria monocytogenes CIP 7831, Listeria monocytogenes Scott A CIP 103575 et Escherichia coli ATCC 25922.

  1. Theoretical study, and construction, of a spherical electrostatic beta spectrometer; Etude theorique et realisation d'un spectrometre beta electrostatique spherique

    Energy Technology Data Exchange (ETDEWEB)

    Moret, R [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1964-03-15

    After a literature survey showing the importance of an electrostatic spectrometer with spherical electrodes for studying disintegration processes, the theoretical characteristics of such an apparatus are derived (determination of the trajectory equations calculation of the transmission and of the resolving power the case of a point source and of an extended source). The apparatus built as a result of these calculations is described. The electrostatic field distribution outside the electrodes is derived. As well as giving electron spectra ({beta} disintegration and conversion electrons) the apparatus make s it possible to study e-{gamma}, e-{beta}, e-e-{gamma} and e-e-{beta} coincidences. In the last part are given experimental characteristics and the results of the first measurements made on conversion electron spectra ({sup 161}Tb, {sup 151}Pm, {sup 155}Eu) and on coincidences ({sup 170}Tm) using this spectrometer. (author) [French] Apres une etude bibliographique montrant l'interet que presente un spectrometre electrostatique a electrodes spheriques pour l'etude des schemas de desintegration, l'auteur etablit les caracteristiques theoriques d'un tel appareil (determination de l'equation des trajectoires calcul de la transmission et du pouvoir de resolution cas d'une source ponctuelle et d'une source etendue). On decrit l'appareil realise d'apres ces calculs. On etablit la repartition du champ electrostatique a l'exterieur des electrodes. Outre le trace des spectres d'electrons (desintegration {beta} et electrons de conversion), l'appareil permet l'etude de coincidences e-{gamma}, e-{beta}, e-e-{gamma} and e-e-{beta}. Dans la derniere partie, sont donnees les caracteristiques experimentales et les premieres etudes de spectres d'electrons de conversion ({sup 161}Tb, {sup 151}Pm, {sup 155}Eu) et de coincidences ({sup 170}Tm) faites a l'aide de ce spectrometre. (auteur)

  2. Rock pushing and sampling under rocks on Mars

    Science.gov (United States)

    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

  3. Point-of-care ultrasonography adoption in Canada: using diffusion theory and the Evaluation Tool for Ultrasound skills Development and Education (ETUDE).

    Science.gov (United States)

    Woo, Michael Y; Frank, Jason R; Lee, A Curtis

    2014-09-01

    Point-of-care ultrasonography (PoCUS) first appeared in the 1980s in North America, but the extent of the diffusion of its adoption is unknown. We characterized early PoCUS adoption by emergency physicians in Canada and its barriers to use using Rogers' diffusion of innovations theory. We developed a questionnaire based on a pilot study and literature review to assess past, current, and potential use of PoCUS and potential barriers to adoption. A Dillman technique for electronic surveys was used for dissemination. Using Rogers' diffusion of innovations theory, we developed and validated the Evaluation Tool for Ultrasound skills Development and Education (ETUDE). ETUDE scores allowed categorization of respondents into innovators, early adopters, majority, and nonadopters. Descriptive statistics, correlations, and χ² statistics were used to analyze the data. The 296 respondents (36.4% of 814 surveyed) had a median age of 40 and were 72.5% male. Adoption scores using ETUDE revealed nonadopters (18.8%), majority (28.7%), early adopters (34.5%), and innovators (18.0%). Respondents endorsed "always" using PoCUS currently and in the future for focused assessment with sonography in trauma (FAST) (current 41.8%/future 88.4%), first trimester pregnancy (current 23.3%/future 73.7%), suspected abdominal aortic aneurysm (current 32.7%/future 92.6%), basic cardiac indications (current 30.7%/future 87.5%), and central venous catheterization (current 17.0%/future 80.3%). Several barriers to PoCUS were identified for part-time emergency physicians and those working in inner-city/urban/suburban settings. This is the first study to determine the state of adoption and barriers to the introduction of PoCUS in Canadian emergency medicine practice. The novel validated ETUDE instrument should be used to evaluate the uptake of PoCUS over time.

  4. Competing exchange interactions and their relevance for the magnetisation process in RMn6-xCrxSn6 powders (R=Y, Gd, Tb, Dy, Ho, Er)

    International Nuclear Information System (INIS)

    Brabers, J.H.V.J.; Zhou, G.F.; Colpa, J.H.P.; Buschow, K.H.J.; De Boer, F.R.

    1994-01-01

    The free-powder magnetisation of RMn 6-x Cr x Sn 6 compounds has been measured for compounds with R=Y, Gd, Tb, Dy, Ho, Er in fields up to 38 T, and interpreted in terms of a simple model, which is also outlined in this paper. From the measurements, estimates for the R-3d mean-field coupling constant (n RT ) could be derived for the cases where R=Gd, Tb, Dy, Ho, Er. In turn, the n RT values can be related to the microscopic spin-coupling constant (J RT ). In the case of YMn 6 Sn 6 the high-field measurement presents evidence for a very weak antiferromagnetic coupling between the Mn layers. Furthermore, values for the Mn moments (μ Mn ) were also derived from the magnetisation measurements. The estimated μ Mn values are of the order of 2.0 μ B . ((orig.))

  5. The formation of scientists and technicians at the 'Centre d'Etudes Nucleaires' at Saclay

    International Nuclear Information System (INIS)

    Debiesse, J.

    1958-01-01

    The considerable needs in research workers and scientists which are asked by the nuclear energy obliged the Commissariat a l'Energie atomique to deal with a particular effort to increase the quantitative and qualitative formation of scientists. Most various ways have been used. 1- A National Institute of Nuclear Sciences and Nuclear Techniques was created, by a joint decree of the Prime Minister and the Minister for National Education (june 18, 1957). This Institute of Higher Teaching (250 students) indulges in the following matters: atomic engineering, quantum mechanics, theory and technic of particle accelerators, special metallurgy, radiobiology, thermic and mechanics of fluids. 2- An associated centre of the 'Conservatoire National des Arts et Metiers' was created (200 students) for technical assistants, drawers, etc. 3- In contribution with both electronic industry and Ministry of Work, the Centre d'Etudes Nucleaires contributes to an accelerated formation of technical assistants into Professional Centres. Conclusion: Training of scientists and research workers is one of the most important activities of the Centre d'Etudes Nucleaires de Saclay. Without losing its technical efficiency, it has supplied and varied means adapted to the various purposes that we shall reach. (author) [fr

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

    Science.gov (United States)

    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.

  7. 'Escher' Rock

    Science.gov (United States)

    2004-01-01

    [figure removed for brevity, see original site] Chemical Changes in 'Endurance' Rocks [figure removed for brevity, see original site] Figure 1 This false-color image taken by NASA's Mars Exploration Rover Opportunity shows a rock dubbed 'Escher' on the southwestern slopes of 'Endurance Crater.' Scientists believe the rock's fractures, which divide the surface into polygons, may have been formed by one of several processes. They may have been caused by the impact that created Endurance Crater, or they might have arisen when water leftover from the rock's formation dried up. A third possibility is that much later, after the rock was formed, and after the crater was created, the rock became wet once again, then dried up and developed cracks. Opportunity has spent the last 14 sols investigating Escher, specifically the target dubbed 'Kirchner,' and other similar rocks with its scientific instruments. This image was taken on sol 208 (Aug. 24, 2004) by the rover's panoramic camera, using the 750-, 530- and 430-nanometer filters. The graph above shows that rocks located deeper into 'Endurance Crater' are chemically altered to a greater degree than rocks located higher up. This chemical alteration is believed to result from exposure to water. Specifically, the graph compares ratios of chemicals between the deep rock dubbed 'Escher,' and the more shallow rock called 'Virginia,' before (red and blue lines) and after (green line) the Mars Exploration Rover Opportunity drilled into the rocks. As the red and blue lines indicate, Escher's levels of chlorine relative to Virginia's went up, and sulfur down, before the rover dug a hole into the rocks. This implies that the surface of Escher has been chemically altered to a greater extent than the surface of Virginia. Scientists are still investigating the role water played in influencing this trend. These data were taken by the rover's alpha particle X-ray spectrometer.

  8. Bio-metric study of pig karyotype; Etude biometrique du caryotype du porc

    Energy Technology Data Exchange (ETDEWEB)

    Haag, J; Lacourly, N; Nizza, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1969-07-01

    This study has a twofold purpose, the former is to determine the swine karyotype as accurately as possible, the latter is to try and develop a method of automatic classification and to show its possibilities and limits. (authors) [French] Cette etude a un double objet: d'une part, de definir de la facon aussi precise que possible le caryotype du porc et d'autre part, de tenter une methode de classification automatique et d'en montrer les possibilites ainsi que les limites. (auteurs)

  9. Rock fragmentation

    Energy Technology Data Exchange (ETDEWEB)

    Brown, W.S.; Green, S.J.; Hakala, W.W.; Hustrulid, W.A.; Maurer, W.C. (eds.)

    1976-01-01

    Experts in rock mechanics, mining, excavation, drilling, tunneling and use of underground space met to discuss the relative merits of a wide variety of rock fragmentation schemes. Information is presented on novel rock fracturing techniques; tunneling using electron beams, thermocorer, electric spark drills, water jets, and diamond drills; and rock fracturing research needs for mining and underground construction. (LCL)

  10. Etude cinétique de la dégradation de l'Endosufane en solution ...

    African Journals Online (AJOL)

    Etude cinétique de la dégradation de l'Endosufane en solution. S Traore, K Mamadou, A Dembele, V Yao, Y Bekro, P Mazellier, B Legube, P Houenou. Abstract. Les pesticides sont fréquemment utilisés en Côte d'Ivoire. Leur détection dans les eaux de forage témoigne de leur mauvais usage et d'un grave problème ...

  11. Rock mechanics for hard rock nuclear waste repositories

    International Nuclear Information System (INIS)

    Heuze, F.E.

    1981-09-01

    The mined geologic burial of high level nuclear waste is now the favored option for disposal. The US National Waste Terminal Storage Program designed to achieve this disposal includes an extensive rock mechanics component related to the design of the wastes repositories. The plan currently considers five candidate rock types. This paper deals with the three hard rocks among them: basalt, granite, and tuff. Their behavior is governed by geological discontinuities. Salt and shale, which exhibit behavior closer to that of a continuum, are not considered here. This paper discusses both the generic rock mechanics R and D, which are required for repository design, as well as examples of projects related to hard rock waste storage. The examples include programs in basalt (Hanford/Washington), in granitic rocks (Climax/Nevada Test Site, Idaho Springs/Colorado, Pinawa/Canada, Oracle/Arizona, and Stripa/Sweden), and in tuff

  12. Elastic Rock Heterogeneity Controls Brittle Rock Failure during Hydraulic Fracturing

    Science.gov (United States)

    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

  13. The use radioactive tracers in the study of solid transport in water streams; Emploi de traceurs radioactifs pour l'etude du transport solide dans les cours d'eau

    Energy Technology Data Exchange (ETDEWEB)

    Courtois, G [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires; Jaffry, P; Heuzel, M [Laboratoire National d' Hydraulique de Chatou, 78 (France)

    1960-07-01

    The Laboratoire National d'Hydraulique which has been studying, during the last few years in conjunction with the Centre d'Etudes Nucleaires at Saclay, the development of apparatus and of methods of investigation of sediment transport by radioactive tracer techniques, is at the moment trying to perfect a genuinely quantitative method of investigation. Two experiments have recently been carried out in rivers, the first designed to investigate the transport of pebbles in the river Rhone, the other to investigate the movement of sands in the Niger. This second experiment has been supported by parallel experiments carried out on a reduced scale model of the Niger built at the laboratories of Chatou: in this experiment are used the radiation from {sup 56}Mn and {sup 24}Na obtained by direct activation of the crushed apricot store which represents, in the scale model, the natural sediment on the bed of the Niger. The combined efforts of the laboratories of Chatou and of the Centre d'Etudes Nucleaires at Saclay are at the moment directed to the application of radioactive tracers to studies on the scale models with the double aim: a) of having a single investigational method for the actual experiment and for the model making it possible to control the accuracy of the model in the preliminary stage of calibrating this model; b) of making the most of the possibilities of observation and of direct measurement offered by the scale models for studying the possibility of improving the tracer method, in particular with respect to the collecting of quantitative data. (author) [French] La Laboratoire National d'Hydraulique qui, depuis quelques annees a developpe, en collaboration avec le Centre d'Etudes Nucleaires de Saclay, les appareillages et les techniques d'etudes des mouvements de sediments par la methode des traceurs radioactifs, s'efforce actuellement de mettre au point un moyen d'investigation veritablement quantitatif. Deux experiences ont ete effectuees recemment en

  14. Rock.XML - Towards a library of rock physics models

    Science.gov (United States)

    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.

  15. Rock burst governance of working face under igneous rock

    Science.gov (United States)

    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.

  16. Etudes sur le Portugal au Temps de l'Humanisme

    Directory of Open Access Journals (Sweden)

    J. Cruz Costa

    1953-06-01

    Full Text Available BATAILLON (Marcel. — Etudes sur le Portugal au Temps de l'Humanisme.  Acta Universitatis Conimbrigencis, 1952, 309 pp. (Primeiro Parágrafo do Artigo O Prof. Marcel Bataillon, erudito dos mais inteligentes da França atual, autor de uma obra que é hoje impr:scindível para quem pretenda estudar o humanismo renascentista na Espanha ou em Portugal, diríamos melhor, talvez: para quem pretenda estudar o Humanismo e a Renascença, — acaba de publicar, na coleção Acta Universitatis Conimbrigencis, êste volume no qual reune alguns trabalhos da mais alta importância para o conhecimento de muitos aspectos da vida espiritual portuguêsa do século XVI.

  17. For Those About to Rock : Naislaulajat rock-genressä

    OpenAIRE

    Herranen, Linda

    2015-01-01

    For those about to rock – naislaulajat rock-genressä antaa lukijalleen kokonaisvaltaisen käsityksen naisista rock-genressä: rockin historiasta, sukupuolittuneisuudesta, seksismistä, suomalaisten naislaulajien menestyksestä. Työn aineisto on koottu aihepiirin kirjallisuudesta ja alalla toimiville naislaulajille teetettyjen kyselyiden tuloksista. Lisäksi avaan omia kokemuksiani ja ajatuksiani, jotta näkökulma naisista rock-genressä tulisi esille mahdollisimman monipuolisesti. Ajatus aihees...

  18. Proceedings of the 3. Canada-US rock mechanics symposium and 20. Canadian rock mechanics symposium : rock engineering 2009 : rock engineering in difficult conditions

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-07-01

    This conference provided a forum for geologists, mining operators and engineers to discuss the application of rock mechanics in engineering designs. Members of the scientific and engineering communities discussed challenges and interdisciplinary elements involved in rock engineering. New geological models and methods of characterizing rock masses and ground conditions in underground engineering projects were discussed along with excavation and mining methods. Papers presented at the conference discussed the role of rock mechanics in forensic engineering. Geophysics, geomechanics, and risk-based approaches to rock engineering designs were reviewed. Issues related to high pressure and high flow water conditions were discussed, and new rock physics models designed to enhance hydrocarbon recovery were presented. The conference featured 84 presentations, of which 9 have been catalogued separately for inclusion in this database. tabs., figs.

  19. Art Rocks with Rock Art!

    Science.gov (United States)

    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…

  20. The development of a very high stability electrostatic generator (1962); Etude et realisation d'un generateur electrostatique a tres haute stabilite (1962)

    Energy Technology Data Exchange (ETDEWEB)

    Jonckheere, R E.L. [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1962-07-01

    This thesis deals with the study of an electrostatic high voltage generator having a voltage stability of the order of 10{sup -6} per minute. This equipment should be very useful in electron microscopy. The electrostatic generator is studied as a control system element: transfer function, parasitic signals and noise are determined and a mathematical model is proposed. A theoretical study of the open loop transfer function, stability, transient response, voltage stabilization of five different control systems shows which one should be able to fulfill the requirements There follows a detailed study of drift, a description of the actual system and performance data. (author) [French] Cette etude concerne un generateur electrostatique capable de fournir une tres haute tension continue dont la stabilite relative est de l'ordre de 10{sup -6} pendant une minute. Une telle performance rend cet appareillage tres utile en microscopie electronique. La generatrice electrostatique est etudiee en tant qu'element d'un systeme asservi: on determine successivement la fonction de transfert, les perturbations, le bruit de fond et le modele mathematique. L'etude de cinq differents circuits de regulation en ce qui concerne leur fonction de transfert, stabilite, reponse en regime transitoire, attenuation des perturbations, permettra de choisir le systeme qui semble le mieux repondre aux exigences. Viennent ensuite une etude detaillee de la derive, la description de la realisation pratique et les resultats de mesure. (auteur)

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

    Science.gov (United States)

    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

  2. Rock Art

    Science.gov (United States)

    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…

  3. Thermally induced rock stress increment and rock reinforcement response

    International Nuclear Information System (INIS)

    Hakala, M.; Stroem, J.; Nujiten, G.; Uotinen, L.; Siren, T.; Suikkanen, J.

    2014-07-01

    This report describes a detailed study of the effect of thermal heating by the spent nuclear fuel containers on the in situ rock stress, any potential rock failure, and associated rock reinforcement strategies for the Olkiluoto underground repository. The modelling approach and input data are presented together repository layout diagrams. The numerical codes used to establish the effects of heating on the in situ stress field are outlined, together with the rock mass parameters, in situ stress values, radiogenic temperatures and reinforcement structures. This is followed by a study of the temperature and stress evolution during the repository's operational period and the effect of the heating on the reinforcement structures. It is found that, during excavation, the maximum principal stress is concentrated at the transition areas where the profile changes and that, due to the heating from the deposition of spent nuclear fuel, the maximum principal stress rises significantly in the tunnel arch area of NW/SW oriented central tunnels. However, it is predicted that the rock's crack damage (CD, short term strength) value of 99 MPa will not be exceeded anywhere within the model. Loads onto the reinforcement structures will come from damaged and loosened rock which is assumed in the modelling as a free rock wedge - but this is very much a worst case scenario because there is no guarantee that rock cracking would form a free rock block. The structural capacity of the reinforcement structures is described and it is predicted that the current quantity of the rock reinforcement is strong enough to provide a stable tunnel opening during the peak of the long term stress state, with damage predicted on the sprayed concrete liner. However, the long term stability and safety can be improved through the implementation of the principles of the Observational Method. The effect of ventilation is also considered and an additional study of the radiogenic heating effect on the brittle

  4. Thermally induced rock stress increment and rock reinforcement response

    Energy Technology Data Exchange (ETDEWEB)

    Hakala, M. [KMS Hakala Oy, Nokia (Finland); Stroem, J.; Nujiten, G.; Uotinen, L. [Rockplan, Helsinki (Finland); Siren, T.; Suikkanen, J.

    2014-07-15

    This report describes a detailed study of the effect of thermal heating by the spent nuclear fuel containers on the in situ rock stress, any potential rock failure, and associated rock reinforcement strategies for the Olkiluoto underground repository. The modelling approach and input data are presented together repository layout diagrams. The numerical codes used to establish the effects of heating on the in situ stress field are outlined, together with the rock mass parameters, in situ stress values, radiogenic temperatures and reinforcement structures. This is followed by a study of the temperature and stress evolution during the repository's operational period and the effect of the heating on the reinforcement structures. It is found that, during excavation, the maximum principal stress is concentrated at the transition areas where the profile changes and that, due to the heating from the deposition of spent nuclear fuel, the maximum principal stress rises significantly in the tunnel arch area of NW/SW oriented central tunnels. However, it is predicted that the rock's crack damage (CD, short term strength) value of 99 MPa will not be exceeded anywhere within the model. Loads onto the reinforcement structures will come from damaged and loosened rock which is assumed in the modelling as a free rock wedge - but this is very much a worst case scenario because there is no guarantee that rock cracking would form a free rock block. The structural capacity of the reinforcement structures is described and it is predicted that the current quantity of the rock reinforcement is strong enough to provide a stable tunnel opening during the peak of the long term stress state, with damage predicted on the sprayed concrete liner. However, the long term stability and safety can be improved through the implementation of the principles of the Observational Method. The effect of ventilation is also considered and an additional study of the radiogenic heating effect on the

  5. Comparison of disposal concepts for rock salt and hard rock

    International Nuclear Information System (INIS)

    Papp, R.

    1998-01-01

    The study was carried out in the period 1994-1996. The goals were to prepare a draft on spent fuel disposal in hard rock and additionally a comparison with existing disposal concepts for rock salt. A cask for direct disposal of spent fuel and a repository for hard rock including a safeguards concept were conceptually designed. The results of the study confirm, that the early German decision to employ rock salt was reasonable. (orig.)

  6. Mechanism of Rock Burst Occurrence in Specially Thick Coal Seam with Rock Parting

    Science.gov (United States)

    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.

  7. Randomized control trial for the assessment of the anti-albuminuric effects of topiroxostat in hyperuricemic patients with diabetic nephropathy (the ETUDE study).

    Science.gov (United States)

    Kato, Sawako; Ando, Masahiko; Mizukoshi, Toshihiro; Nagata, Takanobu; Katsuno, Takayuki; Kosugi, Tomoki; Tsuboi, Naotake; Maruyama, Shoichi

    2016-05-01

    Proteinuria is an established risk factor for diabetic nephropathy. Recent studies indicate that some xanthine oxidase inhibitors have a renoprotective effect. The aim of this study was to assess whether topiroxostat reduces albuminuria in hyperuricemic patients with diabetic nephropathy and overt proteinuria. The ETUDE study is an ongoing 24-week, multicenter, open-label, randomized (1:1), parallel group study involving hyperuricemic patients with diabetic nephropathy (estimated glomerular filtration rate [eGFR] ≥ 20 mL/min/1.73 m(2)) and overt proteinuria (0.3 ≤ urine protein to creatinine ratio (UPCR) ETUDE trial is the first randomized controlled study of topiroxostat in hyperuricemic patients with diabetic nephropathy and overt proteinuria. We will clarify the pleiotropic function of topiroxostat including an anti-albumiuric effect as well as its effects on safely decreasing serum uric acid levels.

  8. Rollerjaw Rock Crusher

    Science.gov (United States)

    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. Range sections as rock models for intensity rock scene segmentation

    CSIR Research Space (South Africa)

    Mkwelo, S

    2007-11-01

    Full Text Available This paper presents another approach to segmenting a scene of rocks on a conveyor belt for the purposes of measuring rock size. Rock size estimation instruments are used to monitor, optimize and control milling and crushing in the mining industry...

  10. Development of a slow mono-kinetic electron source; Etude et realisation d'une source d'electrons lents monocinetiques

    Energy Technology Data Exchange (ETDEWEB)

    Ballu, Y [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1968-06-01

    A comparative study of already existing slow mono-kinetic electron guns shows that those using a 127 degrees electrostatic selector can be improved still further to arrive at the performances obtained with spherical 180 degrees selectors for example. For this reason we have examined the 127 degrees selector theoretically in more detail; it appears that it should be possible to obtain a resolving power better than 30 mV for a current of about 10{sup -10} A, on condition that certain improvements be made to the instrument as normally designed, in particular concerning the entrance and exit slides. As a result, the usual suppressors for the scattered electrons are no longer necessary. The development of this apparatus has been carried out with particular care: the dimensional characteristics are fixed to an accuracy of a few microns, although the instrument can be baked out at 300 C. The experimental results are in excellent agreement with the theoretical predictions: for a current of 10{sup -10} A, the measured resolving power is 24 {+-} 4 mV. The easy detection of the He{sup -} resonance line at 19.3 eV has confirmed the advantages of this apparatus for the study of atomic collisions. (author) [French] L'etude comparative des canons a electrons lents monocinetiques realises jusqu'a present montre que ceux qui utilisent un selecteur electrostatique a 127 degres peuvent etre encore perfectionnes en vue de parvenir aux performances obtenues avec les selecteurs spheriques a 180 degres par exemple. D'ou notre etude theorique approfondie du selecteur a 127 degres qui nous a conduit a esperer une resolution meilleure que 30 mV pour un courant de l'ordre de 10{sup -10} A a condition d'apporter certaines ameliorations a la conception usuelle de cet instrument notamment au niveau des fentes d'entree et de sortie. Par voie de consequence les suppresseurs habituels d'electrons parasites deviennent inutiles. L'etude et la mise au point de l'appareil ont fait l'objet de soins

  11. Methods for studying the radioactive contamination of plants (1963); Methodes d'etude de la contamination radioactive des vegetaux (1963)

    Energy Technology Data Exchange (ETDEWEB)

    Coulon, R; Jeanmaire, L; Michon, G [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1963-07-01

    The authors first define the doctrine which led to the devising of a method for studying the radioactive pollution of plants, based on the use of simple techniques, having the possibility of being adapted for routine work, and so devised that each stage is proceeded with only if the preceding one justifies it. For each stage a study is effected comparing the results obtained by the use of more exact techniques. The second part describes in detail the techniques used. (authors) [French] Dans une premiere partie lea auteurs definissent la doctrine qui leur a permis d'elaborer une methode d'etude de la pollution radioactive des vegetaux, basee sur l'utilisation de techniques simples, se pretant au travail de serie et concues de telle maniere que chaque etape n'est abordee que si la precedente le justifie. Chaque etape fait l'objet d'une etude qui compare les resultats a ceux obtenue par des techniques plus precises. La deuxieme partie decrit dans le detail les techniques utilisees. (auteurs)

  12. Fluid and rock interaction in permeable volcanic rock

    International Nuclear Information System (INIS)

    Lindley, J.I.

    1985-01-01

    Four types of interrelated changes -geochemical, mineralogic, isotopic, and physical - occur in Oligocene volcanic units of the Mogollon-Datil volcanic field, New Mexico. These changes resulted from the operation of a geothermal system that, through fluid-rock interaction, affected 5 rhyolite ash-flow tuffs and an intercalated basaltic andesite lava flow causing a potassium metasomatism type of alteration. (1) Previous studies have shown enrichment of rocks in K 2 O as much as 130% of their original values at the expense of Na 2 O and CaO with an accompanying increase in Rb and decreases in MgO and Sr. (2) X-ray diffraction results of this study show that phenocrystic plagioclase and groundmass feldspar have been replaced with pure potassium feldspar and quartz in altered rock. Phenocrystic potassium feldspar, biotite, and quartz are unaffected. Pyroxene in basaltic andesite is replaced by iron oxide. (3) delta 18 O increases for rhyolitic units from values of 8-10 permil, typical of unaltered rock, to 13-15 permil, typical of altered rock. Basaltic andesite, however, shows opposite behavior with a delta 18 of 9 permil in unaltered rock and 6 permit in altered. (4) Alteration results in a density decrease. SEM revealed that replacement of plagioclase by fine-grained quartz and potassium feldspar is not a volume for volume replacement. Secondary porosity is created in the volcanics by the chaotic arrangement of secondary crystals

  13. The development of a very high stability electrostatic generator (1962); Etude et realisation d'un generateur electrostatique a tres haute stabilite (1962)

    Energy Technology Data Exchange (ETDEWEB)

    Jonckheere, R.E.L. [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1962-07-01

    This thesis deals with the study of an electrostatic high voltage generator having a voltage stability of the order of 10{sup -6} per minute. This equipment should be very useful in electron microscopy. The electrostatic generator is studied as a control system element: transfer function, parasitic signals and noise are determined and a mathematical model is proposed. A theoretical study of the open loop transfer function, stability, transient response, voltage stabilization of five different control systems shows which one should be able to fulfill the requirements There follows a detailed study of drift, a description of the actual system and performance data. (author) [French] Cette etude concerne un generateur electrostatique capable de fournir une tres haute tension continue dont la stabilite relative est de l'ordre de 10{sup -6} pendant une minute. Une telle performance rend cet appareillage tres utile en microscopie electronique. La generatrice electrostatique est etudiee en tant qu'element d'un systeme asservi: on determine successivement la fonction de transfert, les perturbations, le bruit de fond et le modele mathematique. L'etude de cinq differents circuits de regulation en ce qui concerne leur fonction de transfert, stabilite, reponse en regime transitoire, attenuation des perturbations, permettra de choisir le systeme qui semble le mieux repondre aux exigences. Viennent ensuite une etude detaillee de la derive, la description de la realisation pratique et les resultats de mesure. (auteur)

  14. Theory of a metrology for the earths magnetic field based on the resonance of polarised atomic nuclei (1962); Theorie d'une metrologie du champ magnetique terrestre basee sur la resonance de noyaux atomiques polarises (1962)

    Energy Technology Data Exchange (ETDEWEB)

    Bonnet, G [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1961-06-15

    The problems presented by the metrology of the earths field are studied from two points of view. a. The first, purely physical, concerns the study of NMR transducers in their role for the transformation of the magnetic field into a frequency. The possibilities and limitations are outlined. The use of an equivalent model is introduced systematically in the considerations of NMR phenomena, this makes it possible to treat all problems of interaction between a spin system and an electric detection system in a unified form. b. The other point of view concerns the restitution of the nuclear signal frequency in the form of a directly perceptible observable. The treatment of information is considered from a statistical angle, which leads to the study of an optimisation process concerning the linearization of the measurement as well as the minimisation of noise effects. (author) [French] Les problemes que pose la metrologie du champ terrestre sont etudies sous un double aspect: a. L'un, purement physique, concerne l'etude des traducteurs a RMN dans leur role de transformation du champ magnetique en une frequence. On en degage les possibilites et les limitations. L'emploi d'un modele equivalent est introduit de maniere systematique pour rendre compte des phenomenes de RMN, ce qui permet de traiter sous forme unifiee tous les problemes d'interaction entre un systeme de spins et un systeme electrique de detection. b. L'autre aspect concerne la restitution de la frequence du signal nucleaire sous la forme d'une observable directement perceptible. On considere le traitement de l'information sous l'aspect statistique, ce qui amene a etudier un processus d'optimisation concernant la linearisation de la mesure aussi bien que la minimisation des effets des bruits. (auteur)

  15. Disc cutter wear and rock texture in hard rock TBM tunneling

    International Nuclear Information System (INIS)

    Koizumi, Yu; Tsusaka, Kimikazu; Tanimoto, Chikaosa; Nakagawa, Shigeo; Fujita, Naoya

    2008-01-01

    Disc cutter wear in TBM tunneling is caused by initial fragmentation of a solid rock face (the primary fragmentation) and fragmentation of residual rock pieces between a cutterhead and the face (the secondary fragmentation). In two projects through sedimentary and granitic rocks, the authors investigated the relationships between the rate of cutter wear caused by the primary fragmentation, point load index and the grain size and contents of abrasive minerals. As a result, it was found that the tensile strength and the mineral contents of rocks significantly influenced the cutter wear in both projects and thus it is necessary to take into account of rock type. (author)

  16. Contribution to the study of the stability of water-cooled reactors; Contribution a l'etude de la stabilite des reacteurs refroidis par de l'eau

    Energy Technology Data Exchange (ETDEWEB)

    Coudert, C [Commissariat a l' Energie Atomique, Cadarache (France). Centre d' Etudes Nucleaires

    1969-06-01

    This work is devoted to the study of the stability of reactors cooled by water subjected only to natural convection. It is made up of two parts, a theoretical study and experimental work, each of these parts being devoted to a consideration of linear and non-linear conditions: - calculation of the transfer function of the reactor using neutronic and hydrodynamic linear equations with the determination of the instability threshold; - demonstration of the existence of the limiting oscillation cycle in the case of a linear feedback using MALKIN'S method; - measurement and interpretation of the reactor's transfer functions and of the hydrodynamic transfer functions; and - analysis of the noise due to boiling. (author) [French] Dans ce travail on etudie la stabilite des piles refroidies par de l'eau circulant en convection naturelle. Cette etude se divise en deux parties: un travail theorique et un travail experimental, chacune de ces parties comportant une etude lineaire et une etude non-lineaire: - calcul de la fonction de transfert du reacteur a partir des equations lineaires de la neutronique et de l'hydrodynamique avec determination du seuil d'instabilite; - demonstration de l'existence du cycle limite des oscillations dans le cas d'une retroaction lineaire en utilisant la methode de MALKIN; - mesure et interpretation de la fonction de transfert du reacteur et des fonctions de transfert hydrodynamiques; et - analyse du bruit d'ebullition. (auteur)

  17. Rocks Can Wow? Yes, Rocks Can Wow!

    Science.gov (United States)

    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…

  18. Aerodynamic and thermal studies of cans of gas cooled fuel elements; Etudes aerodynamiques et thermiques de gaines d'elements combustibles refroidis par gaz

    Energy Technology Data Exchange (ETDEWEB)

    Gelin, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Milliat, J P [Electricite de France (EDF), 75 - Paris (France)

    1964-07-01

    Research on clusters was undertaken at the CEA in 1959, while studies on herring-bone cans were developed at the EDF Laboratory at Chatou and the CEA laboratory at Saclay at the end of 1959. In 1962, a general study on corrugations was begun at the Saclay Laboratory with a view to improving the clusters, and continued later in both laboratories relative to the internal cooling of annular fuel elements. As these studies progressed, trial facilities were extended while experimental methods have improved constantly. At the present time, both laboratories, working in complete collaboration, have powerful means at their disposal. Work on the clusters has been concerned chiefly with pressure losses due to the assembly parts, and with the temperature variations around the elements of the cluster. In this way, we have been able to determine satisfactorily the hot points of the can, the deformations of the rods and the conditions of stability of these deformations. In the case of the herring-bone cans, studies have been directed to the evolution of performances as a function of the geometric parameters on the one hand, and to the special aerodynamic and thermal features caused by the fins and by interruptions of cartridge on the other hand. These studies have led to a very thorough knowledge of the cartridges chosen for the reactors EDF 2 and EDF 3, and now open up very hopeful prospects for future reactors, particularly those fitted with annular elements; among the alternatives suitable for the inner surface of the annular element can, corrugations and longitudinal fins have been fairly extensively tested over a wide range of Reynolds number. (authors) [French] Les etudes de grappes ont ete entreprises au C.E.A. en 1959, tandis que les etudes de gaines a chevrons se sont developpees au Laboratoire de Chatou de l'EDF et au Laboratoire de Saclay du C.E.A. a la fin de l'annee 1959. En 1962, une etude generale sur les corrugations a ete commencee au Laboratoire de Saclay pour

  19. Aplicación de Resonancia Magnética Nuclear para la caracterización de fracciones pesadas del petróleo en el proceso de desasfaltado por extracción (DEMEX)

    OpenAIRE

    Avella Moreno, Eliseo

    2011-01-01

    En la literatura, se encontró una gran variedad de criterios para la preparación de muestras y para la adquisición y el procesamiento de los espectros de resonancia magnética nuclear de hidrógeno-1 (RMN 1H) o de carbono-13 (RMN 13C) de petróleos, carbones y sus fracciones. Se definieron 33 nuevos intervalos de integración en los espectros de RMN 1H y 47, en los espectros de RMN 13C. Se unificaron sus límites inferior y superior mediante un tratamiento estadístico realizado con ...

  20. Rock Physics

    DEFF Research Database (Denmark)

    Fabricius, Ida Lykke

    2017-01-01

    Rock physics is the discipline linking petrophysical properties as derived from borehole data to surface based geophysical exploration data. It can involve interpretation of both elastic wave propagation and electrical conductivity, but in this chapter focus is on elasticity. Rock physics is based...... on continuum mechanics, and the theory of elasticity developed for statics becomes the key to petrophysical interpretation of velocity of elastic waves. In practice, rock physics involves interpretation of well logs including vertical seismic profiling (VSP) and analysis of core samples. The results...

  1. Mineral and rock chemistry of Mata da Corda Kamafugitic Rocks (Minas Gerais State, Brazil)

    International Nuclear Information System (INIS)

    Albuquerque Sgarbi, Patricia B. de; Valenca, Joel G.

    1995-01-01

    The volcanic rocks of the Mata da Corda Formation (Upper Cretaceous) in Minas Gerais, Brazil, are mafic potassic to ultra potassic rocks of kamafugitic affinity containing essentially clinopyroxenes, perovskite, magnetite and occasionally olivine, phlogopite, melilite pseudomorphs and apatite. The felsic phases are kalsilite and/or leucite pseudomorphs. The rocks are classified as mafitites, leucitites and kalsilitites. The analysis of the available data of the rocks studied, based on the relevant aspects of the main proposals for the classification of alkaline mafic to ultramafic potassic rocks leads to the conclusion that Sahama's (1974) proposal to divide potassium rich alkaline rocks in two large families is the one to which the Mata da Corda rocks adapt best. According to this and the data in the literature on the mineralogy and mineral and rock chemistries of the other similar occurrences, these rocks may be interpreted as alkaline potassic to ultra potassic rocks of hamafugitic affinity. 11 figs., 5 tabs

  2. Rock History and Culture

    OpenAIRE

    Gonzalez, Éric

    2013-01-01

    Two ambitious works written by French-speaking scholars tackle rock music as a research object, from different but complementary perspectives. Both are a definite must-read for anyone interested in the contextualisation of rock music in western popular culture. In Une histoire musicale du rock (i.e. A Musical History of Rock), rock music is approached from the point of view of the people – musicians and industry – behind the music. Christophe Pirenne endeavours to examine that field from a m...

  3. A study of the aptitude of soils under natural conditions to retain radiostrontium; Etude de la vocation des sols en place a la retention du radiostrontium

    Energy Technology Data Exchange (ETDEWEB)

    Bovard, P; Grauby, A [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    Independently of the theoretical study of the propagation of radioactivity in the soil as a result of submersions or of radioactive rain, the authors have studied directly and practically how this radioactivity can vary in the actual soil. To this end a simple, rapid method has been perfected; it makes it possible to maintain for each soil sample the natural parameters (structure, humidity, etc.) without introducing boundary effects. In the laboratory, after charging the soil samples, part of the study of the propagation of radioactivity is done by autoradiography; finally, as a practical application, the study of an atomic site illustrates the methods described. (author) [French] Independamment de l'etude theorique de la propagation de la radioactivite dans le sol a la suite de submersions ou de pluies radioactives, les auteurs ont etudie directement et pratiquement comment pourrait evoluer cette radioactivite dans les sols en place. Pour cela, une methode simple et rapide a ete mise au point; elle permet de conserver pour chaque echantillon de sol, les parametres naturels (structure, humidite, etc...), sans introduire d'effets de paroi. En laboratoire, apres mise en charge des massifs preleves, une partie de l'etude de la propagation des radioelements est realisee par autoradiographie; enfin, une application pratique, l'etude d'un site atomique, illustre l'expose. (auteur)

  4. A study of the aptitude of soils under natural conditions to retain radiostrontium; Etude de la vocation des sols en place a la retention du radiostrontium

    Energy Technology Data Exchange (ETDEWEB)

    Bovard, P.; Grauby, A. [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    Independently of the theoretical study of the propagation of radioactivity in the soil as a result of submersions or of radioactive rain, the authors have studied directly and practically how this radioactivity can vary in the actual soil. To this end a simple, rapid method has been perfected; it makes it possible to maintain for each soil sample the natural parameters (structure, humidity, etc.) without introducing boundary effects. In the laboratory, after charging the soil samples, part of the study of the propagation of radioactivity is done by autoradiography; finally, as a practical application, the study of an atomic site illustrates the methods described. (author) [French] Independamment de l'etude theorique de la propagation de la radioactivite dans le sol a la suite de submersions ou de pluies radioactives, les auteurs ont etudie directement et pratiquement comment pourrait evoluer cette radioactivite dans les sols en place. Pour cela, une methode simple et rapide a ete mise au point; elle permet de conserver pour chaque echantillon de sol, les parametres naturels (structure, humidite, etc...), sans introduire d'effets de paroi. En laboratoire, apres mise en charge des massifs preleves, une partie de l'etude de la propagation des radioelements est realisee par autoradiographie; enfin, une application pratique, l'etude d'un site atomique, illustre l'expose. (auteur)

  5. Study of the dynamic behaviour of the reactor Rapsodie; Etude du comportement dynamique de la pile rapsodie

    Energy Technology Data Exchange (ETDEWEB)

    Abdon, R; Chaigne, M [Commissariat a l' Energie Atomique, Cadarache (France). Centre d' Etudes Nucleaires

    1964-07-01

    . The investigation of the control, carried out on analog computer, served to determine the different possible means of starting and changing the conditions of the reactor as well as its automatic control. The calculations were examined in the totality by the construction of a training simulator composed of a board similar to the control board of the reactor, all of whose commands (reactivity and flows) work on an analogue computer which resolves in the real time the dynamic equations of the reactor and which reproduces simultaneously all the parameters representing the state of the installation (power, period, temperatures, etc. ) in the case of various incidents as well as under normal conditions of functioning. (authors) [French] On sait que le developpement des reacteurs surgenerateurs a neutrons rapides pose des problemes nouveaux d'une part dans les domaines mecanique et thermique et d'autre part en ce qui concerne leur comportement dynamique et leur surete. La pile RAPSODIE a ete l'objet de tres nombreuses etudes dynamiques effectuees sur machines analogiques et digitales, pour deux versions du combustible (metal et oxyde). Apres elaboration des modeles mathematiques representatifs de l'ensemble de l'installation (bloc pile et circuit de refroidissement) tant du point de vue neutronique que du point de vue thermodynamique, on a mis au point les schemas analogiques et les codes digitaux utilisables pour mener a bien les simulations d'incidents, de conduite et de stabilite du reacteur. On s'est attache, par rapport aux methodes habituelles a obtenir une precision plus grande, par un decoupage en zones plus fines, par l'emploi de formulations plus representatives du systeme reel, voire solubles analytiquement. Les etudes d'incidents ont ete effectuees par voie analogique pour l'ensemble de l'installation et par voie digitale pour l'etude du bloc pile seul ou de l'installation fonctionnant avec un seul circuit thermique. Un programme complementaire special - qui, a

  6. Rapid formation of rock armour for soil - rock fragment mixture during simulated rainfall

    Science.gov (United States)

    Poultney, E.; McGrath, G. S.; Hinz, C.

    2009-04-01

    Preventing erosion is an important issue in disturbed semi-arid and arid landscapes. This is in particular of highest importance for mining companies while undertaking land rehabilitation. An onsite investigation of the impact of surface rock fragments on erosion was conducted at Telfer goldmine in the Great Sandy Desert, Western Australia. The study site is a waste rock dump designed to mimic the concave slope of a natural mesa to both discourage erosion and blend in with its natural surroundings. Four treatments were used to construct the slope: two are topsoil mixed with rock fragments, and two are unmixed topsoil. A field study investigating erosion rills, particle size distribution, rock fragment coverage surface roughness and vegetation was carried out to determine changes down and across slope. The treatments constructed by mixing topsoil and rock fragments are more stable and show rock fragment distributions that more closely resemble patterns found on natural mesas surrounding Telfer. A controlled study using trays of topsoil mixed with rock fragment volumes of 50%, 60%, 70% and 80% were used to investigate how varying mixtures of rock fragments and topsoil erode using rainfall intensities between 20 and 100 mm h-1. Two runs of 25 minutes each were used to assess the temporal evolution of rock armouring. Surface coverage results converged for the 50%, 60% and 70% mixtures after the first run to coverage of about 90%, suggesting that fine sediment proportion does not affect rate and degree of rock armouring.

  7. Development of artificial soft rock

    International Nuclear Information System (INIS)

    Kishi, Kiyoshi

    1995-01-01

    When foundation base rocks are deeper than the level of installing structures or there exist weathered rocks and crushed rocks in a part of base rocks, often sound artificial base rocks are made by substituting the part with concrete. But in the construction of Kashiwazaki Kariwa Nuclear Power Station of Tokyo Electric Power Co., Inc., the foundation base rocks consist of mudstone, and the stiffness of concrete is large as compared with the surrounding base rocks. As the quality of the substituting material, the nearly same stiffness as that of the surrounding soft rocks and long term stability are suitable, and the excellent workability and economical efficiency are required, therefore, artificial soft rocks were developed. As the substituting material, the soil mortar that can obtain the physical property values in stable form, which are similar to those of Nishiyama mudstone, was selected. The mechanism of its hardening and the long term stability, and the manufacturing plant are reported. As for its application to the base rocks of Kashiwazaki Kariwa Nuclear Power Station, the verification test at the site and the application to the base rocks for No. 7 plant reactor building and other places are described. (K.I.)

  8. Teaching the Rock Cycle with Ease.

    Science.gov (United States)

    Bereki, Debra

    2000-01-01

    Describes a hands-on lesson for teaching high school students the concept of the rock cycle using sedimentary, metamorphic, and igneous rocks. Students use a rock cycle diagram to identify pairs of rocks. From the rock cycle, students explain on paper how their first rock became the second rock and vice versa. (PVD)

  9. Recreating Rocks

    DEFF Research Database (Denmark)

    Posth, Nicole R

    2008-01-01

    Nicole Posth and colleagues spent a month touring South African rock formations in their quest to understand the origin of ancient iron and silicate layers.......Nicole Posth and colleagues spent a month touring South African rock formations in their quest to understand the origin of ancient iron and silicate layers....

  10. Study: control of atomic energy power plant; Etude de la regulation d'une installation atomique productrice d'energie

    Energy Technology Data Exchange (ETDEWEB)

    Dautray, R; Leny, J C [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    We are studying the control of a very flexible atomic power plant, able to supply an independent network. Two systems have been examined: in the first the moderator pre-heats the light water, in the second, this preheating is dispensed with, subsequent to a study of the dynamics of the plant. Very complete linear approximation study is being effected on the model of the second system, all effects being taken into account. The reactor is stable at all power levels, though slight reactivity or load variations cause undamped power oscillations around the equilibrium level. (author)Fren. [French] Nous etudions la regulation d'une installation atomique d'une grande souplesse, pouvant eventuellement fournir de l'energie a un reseau isole. Deux versions de l'installation sont etudiees: dans la premiere le moderateur sert a rechauffer l'eau industrielle, mais l'etude dynamique conduit a supprimer ce rechauffage, ce qui donne la deuxieme version. On effectue sur celle-ci une etude en approximation lineaire tres complete ou l'on tient compte de differents effets. L'installation se montre stable a tous les niveaux de puissance. Toutefois, de petites perturbations de reactivite ou de charge entrainent des oscillations de puissance mal amorties autour de la position d'equilibre. (auteur)

  11. Hydrological characteristics of Japanese rock

    International Nuclear Information System (INIS)

    Ijiri, Yuji; Sawada, Atsushi; Akahori, Kuniaki

    1999-11-01

    It is crucial to evaluate the hydrogeological characteristics of rock in Japan in order to assess the performance of geosphere. This report summarizes the hydrogeological characteristics of various rock types obtained from broad literature surveys and the fields experiments at the Kamaishi mine in northern Japan and at the Tono mine in central Japan. It is found that the hydraulic conductivity of rock mass ranges from 10 -9 m/s to 10 -8 m/s, whereas the hydraulic conductivity of fault zone ranges from 10 -9 m/s to 10 -3 m/s. It is also found that the hydraulic conductivity tends to decrease with depth. Therefore, the hydraulic conductivity of rock mass at the depth of a repository will be smaller than above values. From the investigations at outcrops and galleries throughout the country, fractures are observed as potential pathways in all rock types. All kinds of crystalline rocks and pre-Neogene sedimentary rocks are classified as fractured media where fracture flow is dominant. Among these rocks, granitic rock is considered the archetype fractured media. On the other hand, andesite, tuff and Neogene sedimentary rocks are considered as intermediate between fractured media and porous media where flow in fractures as well as in rock matrix are significant. (author)

  12. Rock Goes to School on Screen: A Model for Teaching Non-"Learned" Musics Derived from the Films "School of Rock" (2003) and "Rock School" (2005)

    Science.gov (United States)

    Webb, Michael

    2007-01-01

    What can be learned from two films with "rock" and "school" in their titles, about rock in school and about music and schooling more broadly? "School of Rock" (2003), a "family comedy," and "Rock School" (2005), a documentary, provoke a range of questions, ideological and otherwise, surrounding the inclusion of rock in formal instructional…

  13. Grinding into Soft, Powdery Rock

    Science.gov (United States)

    2004-01-01

    This hole in a rock dubbed 'Clovis' is the deepest hole drilled so far in any rock on Mars. NASA's Mars Exploration Rover Spirit captured this view with its microscopic imager on martian sol 217 (Aug. 12, 2004) after drilling 8.9 millimeters (0.35 inch) into the rock with its rock abrasion tool. The view is a mosaic of four frames taken by the microscopic imager. The hole is 4.5 centimeters (1.8 inches) in diameter. Clovis is key to a developing story about environmental change on Mars, not only because it is among the softest rocks encountered so far in Gusev Crater, but also because it contains mineral alterations that extend relatively deep beneath its surface. In fact, as evidenced by its fairly crumbly texture, it is possibly the most highly altered volcanic rock ever studied on Mars. Scientific analysis shows that the rock contains higher levels of the elements sulfur, chlorine, and bromine than are normally encountered in basaltic rocks, such as a rock dubbed 'Humphrey' that Spirit encountered two months after arriving on Mars. Humphrey showed elevated levels of sulfur, chlorine, and bromine only in the outermost 2 millimeters (less than 0.1 inch) of its surface. Clovis shows elevated levels of the same elements along with the associated softness of the rock within a borehole that is 4 times as deep. Scientists hope to compare Clovis to other, less-altered rocks in the vicinity to assess what sort of water-based processes altered the rock. Hypotheses include transport of sulfur, chlorine, and bromine in water vapor in volcanic gases; hydrothermal circulation (flow of volcanically heated water through rock); or saturation in a briny soup containing the same elements. In this image, very fine-grained material from the rock has clumped together by electrostatic attraction and fallen into the borehole. NASA/JPL/Cornell/USGS

  14. THM-coupled modeling of selected processes in argillaceous rock relevant to rock mechanics

    International Nuclear Information System (INIS)

    Czaikowski, Oliver

    2012-01-01

    Scientific investigations in European countries other than Germany concentrate not only on granite formations (Switzerland, Sweden) but also on argillaceous rock formations (France, Switzerland, Belgium) to assess their suitability as host and barrier rock for the final storage of radioactive waste. In Germany, rock salt has been under thorough study as a host rock over the past few decades. According to a study by the German Federal Institute for Geosciences and Natural Resources, however, not only salt deposits but also argillaceous rock deposits are available at relevant depths and of extensions in space which make final storage of high-level radioactive waste basically possible in Germany. Equally qualified findings about the suitability/unsuitability of non-saline rock formations require fundamental studies to be conducted nationally because of the comparatively low level of knowledge. The article presents basic analyses of coupled mechanical and hydraulic properties of argillaceous rock formations as host rock for a repository. The interaction of various processes is explained on the basis of knowledge derived from laboratory studies, and open problems are deduced. For modeling coupled processes, a simplified analytical computation method is proposed and compared with the results of numerical simulations, and the limits to its application are outlined. (orig.)

  15. Seismic response of rock joints and jointed rock mass

    International Nuclear Information System (INIS)

    Ghosh, A.; Hsiung, S.M.; Chowdhury, A.H.

    1996-06-01

    Long-term stability of emplacement drifts and potential near-field fluid flow resulting from coupled effects are among the concerns for safe disposal of high-level nuclear waste (HLW). A number of factors can induce drift instability or change the near-field flow patterns. Repetitive seismic loads from earthquakes and thermal loads generated by the decay of emplaced waste are two significant factors. One of two key technical uncertainties (KTU) that can potentially pose a high risk of noncompliance with the performance objectives of 10 CFR Part 60 is the prediction of thermal-mechanical (including repetitive seismic load) effects on stability of emplacement drifts and the engineered barrier system. The second KTU of concern is the prediction of thermal-mechanical-hydrological (including repetitive seismic load) effects on the host rock surrounding the engineered barrier system. The Rock Mechanics research project being conducted at the Center for Nuclear Waste Regulatory Analyses (CNWRA) is intended to address certain specific technical issues associated with these two KTUs. This research project has two major components: (i) seismic response of rock joints and a jointed rock mass and (ii) coupled thermal-mechanical-hydrological (TMH) response of a jointed rock mass surrounding the engineered barrier system (EBS). This final report summarizes the research activities concerned with the repetitive seismic load aspect of both these KTUs

  16. Effects of confinement on rock mass modulus: A synthetic rock mass modelling (SRM study

    Directory of Open Access Journals (Sweden)

    I. Vazaios

    2018-06-01

    Full Text Available The main objective of this paper is to examine the influence of the applied confining stress on the rock mass modulus of moderately jointed rocks (well interlocked undisturbed rock mass with blocks formed by three or less intersecting joints. A synthetic rock mass modelling (SRM approach is employed to determine the mechanical properties of the rock mass. In this approach, the intact body of rock is represented by the discrete element method (DEM-Voronoi grains with the ability of simulating the initiation and propagation of microcracks within the intact part of the model. The geometry of the pre-existing joints is generated by employing discrete fracture network (DFN modelling based on field joint data collected from the Brockville Tunnel using LiDAR scanning. The geometrical characteristics of the simulated joints at a representative sample size are first validated against the field data, and then used to measure the rock quality designation (RQD, joint spacing, areal fracture intensity (P21, and block volumes. These geometrical quantities are used to quantitatively determine a representative range of the geological strength index (GSI. The results show that estimating the GSI using the RQD tends to make a closer estimate of the degree of blockiness that leads to GSI values corresponding to those obtained from direct visual observations of the rock mass conditions in the field. The use of joint spacing and block volume in order to quantify the GSI value range for the studied rock mass suggests a lower range compared to that evaluated in situ. Based on numerical modelling results and laboratory data of rock testing reported in the literature, a semi-empirical equation is proposed that relates the rock mass modulus to confinement as a function of the areal fracture intensity and joint stiffness. Keywords: Synthetic rock mass modelling (SRM, Discrete fracture network (DFN, Rock mass modulus, Geological strength index (GSI, Confinement

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

    Science.gov (United States)

    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

  18. 19th International Seapower Symposium

    Science.gov (United States)

    2010-07-01

    mentioning about the newly feder- ated T-RMN. RMN stands for Royal Malaysian Navy, that’s where I come from; but actually in this regard, T-RMN stands for...customs offices, with the taxation departments, with organizations that do the ac- tual invoicing, and with the maritime authorities, which in the case...collaborations have also been proposed. Chief of the Royal Malaysian Navy Admiral Abdul Aziz, for example, has mooted the idea of the Maritime

  19. The Rock Cycle

    Science.gov (United States)

    Singh, Raman J.; Bushee, Jonathan

    1977-01-01

    Presents a rock cycle diagram suitable for use at the secondary or introductory college levels which separates rocks formed on and below the surface, includes organic materials, and separates products from processes. (SL)

  20. Water-rock interaction in a high-FeO olivine rock in nature

    International Nuclear Information System (INIS)

    Hellmuth, K.H.; Lindberg, A.; Tullborg, E.L.

    1992-12-01

    The long-term behaviour in nature of high-FeO olivine rock in contact with surface water has been studied at the Lovasjaervi instrusion, SE-Finland. The rock has been proposed as a high-capasity, higly reactive redox-buffer backfill in a repository for spent fuel. Favourable groundwater chemistry is a major parameter relevant to safety of such a repository. Reducing conditions favour the retardation of long-lived, redox-sensitive radionuclides. Weathering influences have been studied at the natural outcrop of the rock mass. The interaction of oxidizing surface waters with rock at greater depths has been studied by using fissure filling minerals. Investigation of weathered rock from the outcrop indicates that the olivine rock is highly reactive on a geological time scale and its redox capasity is available although the instrusion as a whole is surprisingly well preserved. The fissure fillings studied allow the conclusion that oxygen seems to be efficiently removed from intruding surface water. Oxidation seem to have caused visible effects only along very conducting fractures and near the contact zones of the surrounding granitic rock. Stable isotope data of fissure filling calcites indicate that the influence of surface waters can be traced clearly down to a depth of about 50 m, but also at greater depths re-equilibration has occurred. Groundwater data from the site were not available. (orig.)

  1. Cecal bacterial communities in wild Japanese rock ptarmigans and captive Svalbard rock ptarmigans.

    Science.gov (United States)

    Ushida, Kazunari; Segawa, Takahiro; Tsuchida, Sayaka; Murata, Koichi

    2016-02-01

    Preservation of indigenous gastrointestinal microbiota is deemed to be critical for successful captive breeding of endangered wild animals, yet its biology is poorly understood. Here, we investigated cecal bacterial communities in wild Japanese rock ptarmigans (Lagopus muta japonica) and compared them with those in Svalbard rock ptarmigans (L. m. hyperborea) in captivity. Ultra-deep sequencing of 16S rRNA gene indicated that the community structure of cecal microbiota in wild rock ptarmigans was remarkably different from that in captive Svalbard rock ptarmigans. Fundamental differences between bacterial communities in the two groups of birds were detected at the phylum level. Firmicutes, Actinobacteria, Bacteroidetes and Synergistetes were the major phyla detected in wild Japanese rock ptarmigans, whereas Firmicutes alone occupied more than 80% of abundance in captive Svalbard rock ptarmigans. Furthermore, unclassified genera of Coriobacteriaceae, Synergistaceae, Bacteroidaceae, Actinomycetaceae, Veillonellaceae and Clostridiales were the major taxa detected in wild individuals, whereas in zoo-reared birds, major genera were Ruminococcus, Blautia, Faecalibacterium and Akkermansia. Zoo-reared birds seemed to lack almost all rock ptarmigan-specific bacteria in their intestine, which may explain the relatively high rate of pathogenic infections affecting them. We show evidence that preservation and reconstitution of indigenous cecal microflora are critical for successful ex situ conservation and future re-introduction plan for the Japanese rock ptarmigan.

  2. Rock engineering in Finland

    Energy Technology Data Exchange (ETDEWEB)

    1986-01-01

    Contains a large collection of short articles concerned with tunnels and underground caverns and their construction and use. The articles are grouped under the following headings: use of the subsurface space; water supply; waste water services; energy management (includes articles on power stations, district heating and oil storage and an article on coal storage); multipurpose tunnels; waste disposal; transport; shelters; sporting and recreational amenities located in rock caverns; storage facilities; industrial, laboratory, and service facilities; rock foundations; tourism and culture; utilization of rock masses; research on the disposal of nuclear waste; training and research in the field of rock engineering; site investigation techniques; design of structures in rock; construction; the environment and occupational safety; modern equipment technology; underground space in Helsinki.

  3. Sliding rocks on Racetrack Playa, Death Valley National Park: first observation of rocks in motion.

    Directory of Open Access Journals (Sweden)

    Richard D Norris

    Full Text Available The engraved trails of rocks on the nearly flat, dry mud surface of Racetrack Playa, Death Valley National Park, have excited speculation about the movement mechanism since the 1940s. Rock movement has been variously attributed to high winds, liquid water, ice, or ice flotation, but has not been previously observed in action. We recorded the first direct scientific observation of rock movements using GPS-instrumented rocks and photography, in conjunction with a weather station and time-lapse cameras. The largest observed rock movement involved > 60 rocks on December 20, 2013 and some instrumented rocks moved up to 224 m between December 2013 and January 2014 in multiple move events. In contrast with previous hypotheses of powerful winds or thick ice floating rocks off the playa surface, the process of rock movement that we have observed occurs when the thin, 3 to 6 mm, "windowpane" ice sheet covering the playa pool begins to melt in late morning sun and breaks up under light winds of -4-5 m/s. Floating ice panels 10 s of meters in size push multiple rocks at low speeds of 2-5 m/min. along trajectories determined by the direction and velocity of the wind as well as that of the water flowing under the ice.

  4. Rock stresses (Grimsel rock laboratory)

    International Nuclear Information System (INIS)

    Pahl, A.; Heusermann, S.; Braeuer, V.; Gloeggler, W.

    1989-01-01

    On the research and development project 'Rock Stress Measurements' the BGR has developed and tested several test devices and methods at GTS for use in boreholes at a depth of 200 m and has carried out rock mechanical and engineering geological investigations for the evaluation and interpretation of the stress measurements. The first time a computer for data processing was installed in the borehole together with the BGR-probe. Laboratory tests on hollow cylinders were made to study the stress-deformation behavior. To validate and to interprete the measurement results some test methods were modelled using the finite-element method. The dilatometer-tests yielded high values of Young's modulus, whereas laboratory tests showed lower values with a distinct deformation anisotropy. Stress measurements with the BGR-probe yielded horizontal stresses being higher than the theoretical overburden pressure and vertical stresses which agree well with the theoretical overburden pressure. These results are comparable to the results of the hydraulic fracturing tests, whereas stresses obtained with CSIR-triaxial cells are generally lower. The detailed geological mapping of the borehole indicated relationships between stress and geology. With regard to borehole depth different zones of rock structure joint frequency, joint orientation, and orientation of microfissures as well as stress magnitude, stress direction, and degree of deformation anisotropy could be distinguished. (orig./HP) [de

  5. The study of neutron transport by oscillation method; Etude du transport des neutrons par la methode de modulation

    Energy Technology Data Exchange (ETDEWEB)

    Raievski, V

    1959-07-01

    The oscillation method is of very general use for studying the behavior of thermal neutrons in media. The main experiments are described and a general theory of them is given. This theory, which is presented in the first part, is established using the two-group approximation which has proved its efficiency in the case of thermal neutron piles. The validity of the two-group approximation is recalled. This allows definition of the meaning of the parameters used in the theory and which are measured in these experiments. The experiments carried out by this method are described, especially those performed at the Centre d'Etudes Nucleaires de Saclay where the method has been extensively used. These experiments are interpreted by means of the general theory given previously. In this way, the identity of parameters measured by this method and those given by the theory is proved. This is particularly conclusive is the case of the mean life of neutrons in a pile. (author) [French] La methode de modulation est un procede tres general d'etude des proprietes neutroniques des milieux contenant des neutrons thermiques. Le present rapport a pour but de decrire les principales de ces experiences et d'en donner une theorie generale. Cette theorie, exposee dans la premiere partie, est etablie dons le cadre de l'approximation a deux groupes de vitesse qui a prouve son efficacite dons le cas des piles a neutrons thermiques. Le domaine de validite de l'approximation a deux groupes est rappele au debut, ce qui permet de definir avec precision la signification des parametres qui entrent dons la theorie et qui font l'objet de ces mesures. La deuxieme partie decrit les experiences realisees, en particulier celles effectuees au Centre d'Etudes Nucleaires de Saclay ou la methode a ete considerablement developpee. Ces experiences sont interpretees dans le cadre de la theorie generale exposee precedemment. On prouve ainsi l'identite des parametres mesures par cette methode et de ceux figurant

  6. Review on the prevailing methods for the prediction of potential rock burst / rock spalling in tunnels

    OpenAIRE

    Panthi, Krishna Kanta

    2017-01-01

    Rock burst / rock spalling is among the prevailing stability challenges, which can be met while tunneling through hard rock mass. Especially, this is very relevant for the mountainous country like Norway where hard rock is dominating and many road, railway and hydropower tunnels have to be aligned deep into the mountain with steep valley slope topography. Tunnels passing beneath deep rock cover (overburden), in general, are subjected to high in-situ stresses. If the rock mass is relatively un...

  7. Synthetic Rock Analogue for Permeability Studies of Rock Salt with Mudstone

    Directory of Open Access Journals (Sweden)

    Hongwu Yin

    2017-09-01

    Full Text Available Knowledge about the permeability of surrounding rock (salt rock and mudstone interlayer is an important topic, which acts as a key parameter to characterize the tightness of gas storage. The goal of experiments that test the permeability of gas storage facilities in rock salt is to develop a synthetic analogue to use as a permeability model. To address the permeability of a mudstone/salt layered and mixed rock mass in Jintan, Jiangsu Province, synthetic mixed and layered specimens using the mudstone and the salt were fabricated for permeability testing. Because of the gas “slippage effect”, test results are corrected by the Klinkenberg method, and the permeability of specimens is obtained by regression fitting. The results show that the permeability of synthetic pure rock salt is 6.9 × 10−20 m2, and its porosity is 3.8%. The permeability of synthetic mudstone rock is 2.97 × 10−18 m2, with a porosity 17.8%. These results are close to those obtained from intact natural specimens. We also find that with the same mudstone content, the permeability of mixed specimens is about 40% higher than for the layered specimens, and with an increase in the mudstone content, the Klinkenberg permeability increases for both types of specimens. The permeability and mudstone content have a strong exponential relationship. When the mudstone content is below 40%, the permeability increases only slightly with mudstone content, whereas above this threshold, the permeability increases rapidly with mudstone content. The results of the study are of use in the assessment of the tightness of natural gas storage facilities in mudstone-rich rock salt formations in China.

  8. 'Mister Badger' Pushing Mars Rock

    Science.gov (United States)

    1976-01-01

    Viking's soil sampler collector arm successfully pushed a rock on the surface of Mars during the afternoon of Friday, October 8. The irregular-shaped rock was pushed several inches by the Lander's collector arm, which displaced the rock to the left of its original position, leaving it cocked slightly upward. Photographs and other information verified the successful rock push. Photo at left shows the soil sampler's collector head pushing against the rock, named 'Mister Badger' by flight controllers. Photo at right shows the displaced rock and the depression whence it came. Part of the soil displacement was caused by the collector s backhoe. A soil sample will be taken from the site Monday night, October 11. It will then be delivered to Viking s organic chemistry instrument for a series of analyses during the next few weeks. The sample is being sought from beneath a rock because scientists believe that, if there are life forms on Mars, they may seek rocks as shelter from the Sun s intense ultraviolet radiation.

  9. Source rock

    Directory of Open Access Journals (Sweden)

    Abubakr F. Makky

    2014-03-01

    Full Text Available West Beni Suef Concession is located at the western part of Beni Suef Basin which is a relatively under-explored basin and lies about 150 km south of Cairo. The major goal of this study is to evaluate the source rock by using different techniques as Rock-Eval pyrolysis, Vitrinite reflectance (%Ro, and well log data of some Cretaceous sequences including Abu Roash (E, F and G members, Kharita and Betty formations. The BasinMod 1D program is used in this study to construct the burial history and calculate the levels of thermal maturity of the Fayoum-1X well based on calibration of measured %Ro and Tmax against calculated %Ro model. The calculated Total Organic Carbon (TOC content from well log data compared with the measured TOC from the Rock-Eval pyrolysis in Fayoum-1X well is shown to match against the shale source rock but gives high values against the limestone source rock. For that, a new model is derived from well log data to calculate accurately the TOC content against the limestone source rock in the study area. The organic matter existing in Abu Roash (F member is fair to excellent and capable of generating a significant amount of hydrocarbons (oil prone produced from (mixed type I/II kerogen. The generation potential of kerogen in Abu Roash (E and G members and Betty formations is ranging from poor to fair, and generating hydrocarbons of oil and gas prone (mixed type II/III kerogen. Eventually, kerogen (type III of Kharita Formation has poor to very good generation potential and mainly produces gas. Thermal maturation of the measured %Ro, calculated %Ro model, Tmax and Production index (PI indicates that Abu Roash (F member exciting in the onset of oil generation, whereas Abu Roash (E and G members, Kharita and Betty formations entered the peak of oil generation.

  10. Interim rock mass properties and conditions for analyses of a repository in crystalline rock

    International Nuclear Information System (INIS)

    Tammemagi, H.Y.; Chieslar, J.D.

    1985-03-01

    A summary of rock properties for generic crystalline rock is compiled from literature sources to provide the input data for analyses of a conceptual repository in crystalline rock. Frequency histograms, mean values and ranges of physical, mechanical, thermal, and thermomechanical properties, and the dependence of these properties on temperature are described. A description of the hydrogeologic properties of a crystalline rock mass and their dependence on depth is provided. In addition, the temperature gradients, mean annual surface temperature, and in situ stress conditions are summarized for the three regions of the United States currently under consideration to host a crystalline repository; i.e., the North Central, Northeastern, and Southeastern. Brief descriptions of the regional geology are also presented. Large-scale underground experiments in crystalline rock at Stripa, Sweden, and in Climax Stock in Nevada, are reviewed to assess whether the rock properties presented in this report are representative of in situ conditions. The suitability of each rock property and the sufficiency of its data base are described. 110 refs., 27 figs., 4 tabs

  11. Basic rocks in Finland

    International Nuclear Information System (INIS)

    Piirainen, T.; Gehoer, S.; Iljina, M.; Kaerki, A.; Paakkola, J.; Vuollo, J.

    1992-10-01

    Basic igneous rocks, containing less than 52% SiO 2 , constitute an important part of the Finnish Archaean and Proterozoic crust. In the Archaean crust exist two units which contain the majority of the basic rocks. The Arcaean basic rocks are metavolcanics and situated in the Greenstone Belts of Eastern Finland. They are divided into two units. The greenstones of the lower one are tholeiites, komatiites and basaltic komatiites. The upper consists of bimodal series of volcanics and the basic rocks of which are Fe-tholeiites, basaltic komatiites and komatiites. Proterozoic basic rocks are divided into seven groups according to their ages. The Proterozoic igneous activity started by the volominous basic magmatism 2.44 Ga ago. During this stage formed the layered intrusions and related dykes in the Northern Finland. 2.2 Ga old basic rocks are situated at the margins of Karelian formations. 2.1 Ga aged Fe-tholeiitic magmatic activity is widespread in Eastern and Northern Finland. The basic rocks of 1.97 Ga age group are met within the Karelian Schist Belts as obducted ophiolite complexes but they occur also as tholeiitic diabase dykes cutting the Karelian schists and Archean basement. The intrusions and the volcanics of the 1.9 Ga old basic igneous activity are mostly encountered around the Granitoid Complex of Central Finland. Subjotnian, 1.6 Ga aged tholeiitic diabases are situated around the Rapakivi massifs of Southern Finland, and postjotnian, 1.2 Ga diabases in Western Finland where they form dykes cutting Svecofennian rocks

  12. Pore-scale analysis of electrical properties in thinly bedded rock using digital rock physics

    International Nuclear Information System (INIS)

    Sun, Jianmeng; Zhao, Jianpeng; Liu, Xuefeng; Chen, Hui; Jiang, LiMing; Zhang, JinYan

    2014-01-01

    We investigated the electrical properties of laminated rock consist of macro-porous layers and micro-porous layers based on digital rock technology. Due to the bedding effect and anisotropy, traditional Archie equations cannot well describe the electrical behavior of laminated rock. The RI-Sw curve of laminated rock shows a nonlinear relationship. The RI-Sw curve can be divided into two linear segments with different saturation exponent. Laminated sand-shale sequences and laminated sands of different porosity or grain size will yield macroscopic electrical anisotropy. Numerical simulation and theoretical analysis lead to the conclusion that electrical anisotropy coefficient of laminated rock is a strong function of water saturation. The function curve can be divided into three segments by the turning point. Therefore, the electrical behavior of laminated rock should be considered in oil exploration and development. (paper)

  13. Research into basic rocks types

    International Nuclear Information System (INIS)

    1993-06-01

    Teollisuuden Voima Oy (TVO) has carried out research into basic rock types in Finland. The research programme has been implemented in parallel with the preliminary site investigations for radioactive waste disposal in 1991-1993. The program contained two main objectives: firstly, to study the properties of the basic rock types and compare those with the other rock types under the investigation; secondly, to carry out an inventory of rock formations consisting of basic rock types and suitable in question for final disposal. A study of environmental factors important to know regarding the final disposal was made of formations identified. In total 159 formations exceeding the size of 4 km 2 were identified in the inventory. Of these formations 97 were intrusive igneous rock types and 62 originally extrusive volcanic rock types. Deposits consisting of ore minerals, industrial minerals or building stones related to these formations were studied. Environmental factors like natural resources, protected areas or potential for restrictions in land use were also studied

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

    Science.gov (United States)

    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.

  15. Contribution to the study of hydrogenated and oxygenated impurities in liquid sodium; Contribution a l'etude des impuretees hydrogenees et oxygenees dans le sodium liquide

    Energy Technology Data Exchange (ETDEWEB)

    Naud, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-15

    This study is made up essentially of two parts. The first is devoted to the development of dosage methods for selectively determining the oxygenated and hydrogenated impurities present in sodium, that is the oxide, the hydride and the hydroxide. The second makes use of these methods for a study of the Na-H{sub 2}-O{sub 2} system, as well as of the related problem of the attack of pyrex glass by molten sodium. The conventional method for dosing oxygen by amalgamation was first adapted to the simultaneous measurement of the hydride. We then developed a method for dosing the total hydrogen by measuring successively the concentrations of gas present in the hydride and hydroxide form. This method is based on the thermal decomposition of the hydride and the reaction between sodium and the hydroxide. Our contribution to the study of the Na-H{sub 2}-O{sub 2} System consists first of all in the study of the reaction between hydrogen and sodium in the temperature range from 150 to 250 deg C and at a pressure of about 150 mm of mercury. The study of the thermal decomposition of the hydride in sodium was then studied. It was possible to make some qualitative observations concerning the reaction between sodium and sodium hydroxide. Finally some complementary tests made it possible to define the nature of the phenomena occurring during the attack of pyrex glass by sodium. (author) [French] Cette etude comporte essentiellement deux parties. La premiere est consacree a la mise au point de methodes de dosages permettant de determiner selectivement les impuretes oxygenees et hydrogenees presentes dans le sodium, a savoir l'oxyde, l'hydrure et l'hydroxyde. La seconde met a profit ces methodes en vue de l'etude du systeme Na-H{sub 2}-O{sub 2}. ainsi que du phenomene connexe d'attaque du verre pyrex par le sodium fondu. La methode classique de dosage de l'oxygene par amalgamation a d'abord ete adaptee au dosage simultane de l'hydrure. Nous avons ensuite mis au point le dosage de l

  16. Igneous Rocks

    Science.gov (United States)

    Doe, Bruce R.

    “Igneous Rocks was written for undergraduate geology majors who have had a year of college-level chemistry and a course in mineralogy … and for beginning graduate students. Geologists working in industry, government, or academia should find this text useful as a guide to the technical literature up to 1981 and as an overview of topics with which they have not worked but which may have unanticipated pertinence to their own projects.” So starts the preface to this textbook.As one who works part time in research on igneous rocks, especially as they relate to mineral deposits, I have been looking for such a book with this avowed purpose in a field that has a choking richness of evolving terminology and a bewildering volume of interdisciplinary literature. In addition to the standard topics of igneous petrology, the book contains a chapter on the role of igneous activity in the genesis of mineral deposits, its value to geothermal energy, and the potential of igneous rocks as an environment for nuclear waste disposal. These topics are presented rather apologetically in the preface, but the author is to be applauded for including this chapter. The apology shows just how new these interests are to petrology. Recognition is finally coming that, for example, mineral deposits are not “sports of nature,” a view held even by many economic geologists as recently as the early 1960's; instead they are perfectly ordinary geochemical features formed by perfectly ordinary geologic processes. In fact, the mineral deposits and their attendant alteration zones probably have as much to tell us about igneous rocks as the igneous rocks have to tell us about mineral deposits.

  17. Radioactivities (dose rates) of rocks in Japan

    International Nuclear Information System (INIS)

    Matsuda, Hideharu; Minato, Susumu

    1995-01-01

    The radioactive distribution (radiation doses) of major rocks in Japan was monitored to clarify the factors influencing terrestrial gamma-ray absorbed dose rates. The rock samples were reduced to powder and analyzed by well-type NaI(Tl) scintillation detector and pulse height analyzer. Terrestrial gamma-ray dose rates were estimated in terms of gamma radiation dose rate 1 m above the ground. The radioactivity concentration was highest in acidic rock which contains much SiO 2 among igneous rock, followed by neutral rock, basic rock, and ultrabasic rock. The radioactive concentration was 30-40% lower in acidic and clastic rocks than those of the world average concentration. Higher radioactive concentration was observed in soils than the parent rocks of sedimentary rock and metamorphic rock. The gamma radiation dose rate was in proportion to the radioactive concentration of the rocks. To clarify the radioactive effect in the change course of rocks into soils, comparative measurement of outcrop and soil radioactive concentrations is important. (S.Y.)

  18. Rock critics as 'Mouldy Modernists'

    Directory of Open Access Journals (Sweden)

    Becky Shepherd

    2011-08-01

    Full Text Available Contemporary rock criticism appears to be firmly tied to the past. The specialist music press valorise rock music of the 1960s and 1970s, and new emerging artists are championed for their ‘retro’ sounding music by journalists who compare the sound of these new artists with those included in the established ‘canon’ of rock music. This article examines the narrative tropes of authenticity and nostalgia that frame the retrospective focus of this contemporary rock writing, and most significantly, the maintenance of the rock canon within contemporary popular culture. The article concludes by suggesting that while contemporary rock criticism is predominately characterised by nostalgia, this nostalgia is not simply a passive romanticism of the past. Rather, this nostalgia fuels a process of active recontextualisation within contemporary popular culture.

  19. Bioremediation in fractured rock: 2. Mobilization of chloroethene compounds from the rock matrix

    Science.gov (United States)

    Shapiro, Allen M.; Tiedeman, Claire; Imbrigiotta, Thomas; Goode, Daniel J.; Hsieh, Paul A.; Lacombe, Pierre; DeFlaun, Mary F.; Drew, Scott R.; Curtis, Gary P.

    2018-01-01

    A mass balance is formulated to evaluate the mobilization of chlorinated ethene compounds (CE) from the rock matrix of a fractured mudstone aquifer under pre- and postbioremediation conditions. The analysis relies on a sparse number of monitoring locations and is constrained by a detailed description of the groundwater flow regime. Groundwater flow modeling developed under the site characterization identified groundwater fluxes to formulate the CE mass balance in the rock volume exposed to the injected remediation amendments. Differences in the CE fluxes into and out of the rock volume identify the total CE mobilized from diffusion, desorption, and nonaqueous phase liquid dissolution under pre- and postinjection conditions. The initial CE mass in the rock matrix prior to remediation is estimated using analyses of CE in rock core. The CE mass mobilized per year under preinjection conditions is small relative to the total CE mass in the rock, indicating that current pump-and-treat and natural attenuation conditions are likely to require hundreds of years to achieve groundwater concentrations that meet regulatory guidelines. The postinjection CE mobilization rate increased by approximately an order of magnitude over the 5 years of monitoring after the amendment injection. This rate is likely to decrease and additional remediation applications over several decades would still be needed to reduce CE mass in the rock matrix to levels where groundwater concentrations in fractures achieve regulatory standards.

  20. Regulation of ROCK Activity in Cancer

    DEFF Research Database (Denmark)

    Morgan-Fisher, Marie; Wewer, Ulla M; Yoneda, Atsuko

    2013-01-01

    , these findings demonstrate additional modes to regulate ROCK activity. This review describes the molecular mechanisms of ROCK activity regulation in cancer, with emphasis on ROCK isoform-specific regulation and interaction partners, and discusses the potential of ROCKs as therapeutic targets in cancer.......Cancer-associated changes in cellular behavior, such as modified cell-cell contact, increased migratory potential, and generation of cellular force, all require alteration of the cytoskeleton. Two homologous mammalian serine/threonine kinases, Rho-associated protein kinases (ROCK I and II), are key...... regulators of the actin cytoskeleton acting downstream of the small GTPase Rho. ROCK is associated with cancer progression, and ROCK protein expression is elevated in several types of cancer. ROCKs exist in a closed, inactive conformation under quiescent conditions, which is changed to an open, active...

  1. A review of micro-wave techniques in plasma studies; Survol des techniques micro-ondes pour l'etude des plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Consoli, T [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    The problem of the application of micro-wave techniques to the study of plasma properties is considered in this report. In section I, the author summarizes a few fundamental laws concerning the theory of waves in an ionised medium as well as measurable effects of transverse and longitudinal propagation. Section II is a rapid review of the experimental methods and of the various measurements which may be effected in very high frequency plasmas. Only recent experimental work carried out since the last U. R.S.I. Assembly is considered. Section III is devoted to micro-wave techniques developed during this period in the laboratories of the Applied Physics Service. These techniques deal with longitudinal propagation and in particular with the propagation along a right mode. Section IV is a general view of similar studies undertaken in European Research Centres working on plasma physics or controlled fusion. Section V is a contribution concerning three particular topics from the Juelich and Max Planck Institute laboratories. (author) [French] On etudie dans ce rapport le probleme de l'application des techniques micro-ondes a l'etude des proprietes d'un plasma. Dans la section I, l'auteur rappelle rapidement quelques lois fondamentales de la theorie des ondes dans un milieu ionise ainsi que les effets mesurables en propagation transversale et longitudinale. La section II est une revue rapide des methodes experimentales et des diverses mesures qui peuvent etre faites dans les plasmas aux tres hautes frequences. On ne considere seulement que les etudes experimentales recentes depuis la derniere assemblee de l'U.R.S.I. La section III est consacree aux techniques hyperfrequences developpees durant la meme periode dans les laboratoires des Services de Physique Appliquee. Ces techniques se rapportent a la propagation longitudinale et particulierement a la propagation suivant le mode droit. La section IV est un panorama de travaux similaires entrepris dans les centres europeens

  2. Rock stress measurements in the Grimsel Underground Rock Laboratory and their geological interpretation

    International Nuclear Information System (INIS)

    Braeuer, V.; Heusermann, S.; Pahl, A.

    1989-01-01

    Rock stress is being studied as part of the Swiss-German cooperation between the National Cooperative for the Storage of Radioactive Waste (NAGRA), the Research Centre for Environmental Sciences (GSF), and the Federal Institute for Geosciences and Natural Resources (BGR) in the Grimsel Rock Laboratory in Switzerland. Several methods and various equipment for measuring rock stress have been developed and tested in an approximately 200-m borehole drilled from a gallery at a depth of 450 m. The measurements were made continually during overcoring; the data were recorded and processed in a computer located downhole or outside the borehole. The results of the overcoring tests and of frac tests indicate a principle horizontal stress of 25-40 MPa, directed mainly NW-SE. Detailed geological mapping shows relationships between stress and rock structure. A zone of nearly unfractured rock exhibits an increase in stress and a change in stress direction. (orig.)

  3. Rock in Rio: forever young

    Directory of Open Access Journals (Sweden)

    Ricardo Ferreira Freitas

    2014-12-01

    Full Text Available The purpose of this article is to discuss the role of Rock in Rio: The Musical, as herald of megafestival Rock in Rio. Driven by the success that musicals have reached in Brazil, we believe that the design of this spectacle of music, dance and staging renews the brand of the rock festival, once it adds the force of young and healthy bodies to its concept. Moreover, the musical provides Rock in Rio with some distance from the controversal trilogy of sex, drugs and rock and roll, a strong mark of past festivals around the world. Thus, the musical expands the possibilities of growth for the brand.

  4. Hydrogeomechanics for rock engineering: coupling subsurface hydrogeomechanical assessement and hydrogeotechnical mapping on fracturated rock masses

    OpenAIRE

    Meirinhos, João Miguel de Freitas

    2015-01-01

    The present work aims to achieve and further develop a hydrogeomechanical approach in Caldas da Cavaca hydromineral system rock mass (Aguiar da Beira, NW Portugal), and contribute to a better understanding of the hydrogeological conceptual site model. A collection of several data, namely geology, hydrogeology, rock and soil geotechnics, borehole hydraulics and hydrogeomechanics, was retrieved from three rock slopes (Lagoa, Amores and Cancela). To accomplish a comprehensive analysis and rock e...

  5. Underground Research Laboratories for Crystalline Rock and Sedimentary Rock in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Shigeta, N.; Takeda, S.; Matsui, H.; Yamasaki, S.

    2003-02-27

    The Japan Nuclear Cycle Development Institute (JNC) has started two off-site (generic) underground research laboratory (URL) projects, one for crystalline rock as a fractured media and the other for sedimentary rock as a porous media. This paper introduces an overview and current status of these projects.

  6. Regulation of ROCK Activity in Cancer

    Science.gov (United States)

    Morgan-Fisher, Marie; Wewer, Ulla M.

    2013-01-01

    Cancer-associated changes in cellular behavior, such as modified cell-cell contact, increased migratory potential, and generation of cellular force, all require alteration of the cytoskeleton. Two homologous mammalian serine/threonine kinases, Rho-associated protein kinases (ROCK I and II), are key regulators of the actin cytoskeleton acting downstream of the small GTPase Rho. ROCK is associated with cancer progression, and ROCK protein expression is elevated in several types of cancer. ROCKs exist in a closed, inactive conformation under quiescent conditions, which is changed to an open, active conformation by the direct binding of guanosine triphosphate (GTP)–loaded Rho. In recent years, a number of ROCK isoform-specific binding partners have been found to modulate the kinase activity through direct interactions with the catalytic domain or via altered cellular localization of the kinases. Thus, these findings demonstrate additional modes to regulate ROCK activity. This review describes the molecular mechanisms of ROCK activity regulation in cancer, with emphasis on ROCK isoform-specific regulation and interaction partners, and discusses the potential of ROCKs as therapeutic targets in cancer. PMID:23204112

  7. Bioremediation in Fractured Rock: 2. Mobilization of Chloroethene Compounds from the Rock Matrix.

    Science.gov (United States)

    Shapiro, Allen M; Tiedeman, Claire R; Imbrigiotta, Thomas E; Goode, Daniel J; Hsieh, Paul A; Lacombe, Pierre J; DeFlaun, Mary F; Drew, Scott R; Curtis, Gary P

    2018-03-01

    A mass balance is formulated to evaluate the mobilization of chlorinated ethene compounds (CE) from the rock matrix of a fractured mudstone aquifer under pre- and postbioremediation conditions. The analysis relies on a sparse number of monitoring locations and is constrained by a detailed description of the groundwater flow regime. Groundwater flow modeling developed under the site characterization identified groundwater fluxes to formulate the CE mass balance in the rock volume exposed to the injected remediation amendments. Differences in the CE fluxes into and out of the rock volume identify the total CE mobilized from diffusion, desorption, and nonaqueous phase liquid dissolution under pre- and postinjection conditions. The initial CE mass in the rock matrix prior to remediation is estimated using analyses of CE in rock core. The CE mass mobilized per year under preinjection conditions is small relative to the total CE mass in the rock, indicating that current pump-and-treat and natural attenuation conditions are likely to require hundreds of years to achieve groundwater concentrations that meet regulatory guidelines. The postinjection CE mobilization rate increased by approximately an order of magnitude over the 5 years of monitoring after the amendment injection. This rate is likely to decrease and additional remediation applications over several decades would still be needed to reduce CE mass in the rock matrix to levels where groundwater concentrations in fractures achieve regulatory standards. © 2017, National Ground Water Association.

  8. Eos Chaos Rocks

    Science.gov (United States)

    2006-01-01

    11 January 2006 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows light-toned, layered rock outcrops in Eos Chaos, located near the east end of the Valles Marineris trough system. The outcrops occur in the form of a distinct, circular butte (upper half of image) and a high slope (lower half of image). The rocks might be sedimentary rocks, similar to those found elsewhere exposed in the Valles Marineris system and the chaotic terrain to the east of the region. Location near: 12.9oS, 49.5oW Image width: 3 km (1.9 mi) Illumination from: lower left Season: Southern Summer

  9. Modeling the Rock Glacier Cycle

    Science.gov (United States)

    Anderson, R. S.; Anderson, L. S.

    2016-12-01

    Rock glaciers are common in many mountain ranges in which the ELA lies above the peaks. They represent some of the most identifiable components of today's cryosphere in these settings. Their oversteepened snouts pose often-overlooked hazards to travel in alpine terrain. Rock glaciers are supported by avalanches and by rockfall from steep headwalls. The winter's avalanche cone must be sufficiently thick not to melt entirely in the summer. The spatial distribution of rock glaciers reflects this dependence on avalanche sources; they are most common on lee sides of ridges where wind-blown snow augments the avalanche source. In the absence of rockfall, this would support a short, cirque glacier. Depending on the relationship between rockfall and avalanche patterns, "talus-derived" and "glacier-derived" rock glaciers are possible. Talus-derived: If the spatial distribution of rock delivery is similar to the avalanche pattern, the rock-ice mixture will travel an englacial path that is downward through the short accumulation zone before turning upward in the ablation zone. Advected debris is then delivered to the base of a growing surface debris layer that reduces the ice melt rate. The physics is identical to the debris-covered glacier case. Glacier-derived: If on the other hand rockfall from the headwall rolls beyond the avalanche cone, it is added directly to the ablation zone of the glacier. The avalanche accumulation zone then supports a pure ice core to the rock glacier. We have developed numerical models designed to capture the full range of glacier to debris-covered glacier to rock glacier behavior. The hundreds of meter lengths, tens of meters thicknesses, and meter per year speeds of rock glaciers are well described by the models. The model can capture both "talus-derived" and "glacier-derived" rock glaciers. We explore the dependence of glacier behavior on climate histories. As climate warms, a pure ice debris-covered glacier can transform to a much shorter rock

  10. Critical issues in soft rocks

    OpenAIRE

    Milton Assis Kanji

    2014-01-01

    This paper discusses several efforts made to study and investigate soft rocks, as well as their physico-mechanical characteristics recognized up to now, the problems in their sampling and testing, and the possibility of its reproduction through artificially made soft rocks. The problems in utilizing current and widespread classification systems to some types of weak rocks are also discussed, as well as other problems related to them. Some examples of engineering works in soft rock or in soft ...

  11. Attempt of groundwater dating using the drilled rock core. 1. Development of the rock sampling method for measurement of noble gases dissolved in interstitial water in rock

    International Nuclear Information System (INIS)

    Mahara, Yasunori

    2002-01-01

    Groundwater dating in low permeable rock is very difficult and impracticable, because we take a very long time to collect groundwater sample in a borehole and have to invest much fund in production of the in-situ groundwater sampler and in operation of it. If we can directly measure noble gases dissolved in interstitial groundwater in rock core, we have a big merit to estimate groundwater resident time easy. In this study, we designed and produced a high vacuum container to let dissolved noble gases diffuse until reaching in equilibrium, and we made a handling manual of the rock core into the container and a procedure to vacuum out air from the sealed container. We compared data sets of noble gas concentration obtained from rock cores and groundwater sample collected from boreholes in-situ. The measured rocks are pumice-tuff rock, mud rock and hornfels, which have their permeabilities of 10 -6 cm/s, 10 -9 cm/s and 10 -11 cm/s, respectively. Consequently, we evaluated the rock core method is better than the in-situ groundwater sampling method for low permeable rock. (author)

  12. Current status of crushed rock and whole rock column studies

    International Nuclear Information System (INIS)

    Vine, E.N.; Daniels, W.R.; Rundberg, R.S.; Thompson, J.L.

    1980-01-01

    Measurements on a large number of crushed rock columns of tuff, granite, and argillite are discussed. The isotopes 85 Sr, 137 Cs, 133 Ba, 141 Ce, 152 Eu, /sup 95m/Tc, and 233 U were used. Flow rates were varied from approx. 30 to approx. 30000 m/y. Other parameters studied include isotope concentration and atmosphere. The sorption ratios calculated were compared with batch sorption ratios on the same samples. Methods of studying the movement of radionuclides through whole rock cores are described. The problems associated with sealing the cores to prevent leaking along the exterior surface and one possible solution are discussed. The strontium sorption ratio obtained by elution of one solid tuff core is compared with the batch and crushed rock column sorption ratios

  13. Assessment of rock mass quality based on rock quality designation and rock block index. Taking the Borehole BS01 in Beishan HLW disposal repository as example

    International Nuclear Information System (INIS)

    Xu Jian; Wang Ju

    2006-01-01

    Rock mass quality assessment plays an important role in the security for all kinds of large-scale buildings, especially for the underground buildings. In this paper, based on two parameters of RQD and RBI, taking the Borehole BS01 as example, lots of measured data prove that the rock block index can reflect the integrity and corresponding variation of mechanical properties of core from Borehole BS01 to some extent. Meanwhile, the rock mass classification around the Borehole BS01 is given in this paper. Finally, comparison of the results for rock mass assessment between RBI and RQD is made. The research result shows that the rock block index has remarkable significance in engineering and advantages in rock mass quality assessment. (authors)

  14. Rock suitability classification RSC 2012

    Energy Technology Data Exchange (ETDEWEB)

    McEwen, T. (ed.) [McEwen Consulting, Leicester (United Kingdom); Kapyaho, A. [Geological Survey of Finland, Espoo (Finland); Hella, P. [Saanio and Riekkola, Helsinki (Finland); Aro, S.; Kosunen, P.; Mattila, J.; Pere, T.

    2012-12-15

    This report presents Posiva's Rock Suitability Classification (RSC) system, developed for locating suitable rock volumes for repository design and construction. The RSC system comprises both the revised rock suitability criteria and the procedure for the suitability classification during the construction of the repository. The aim of the classification is to avoid such features of the host rock that may be detrimental to the favourable conditions within the repository, either initially or in the long term. This report also discusses the implications of applying the RSC system for the fulfilment of the regulatory requirements concerning the host rock as a natural barrier and the site's overall suitability for hosting a final repository of spent nuclear fuel.

  15. Rock suitability classification RSC 2012

    International Nuclear Information System (INIS)

    McEwen, T.; Kapyaho, A.; Hella, P.; Aro, S.; Kosunen, P.; Mattila, J.; Pere, T.

    2012-12-01

    This report presents Posiva's Rock Suitability Classification (RSC) system, developed for locating suitable rock volumes for repository design and construction. The RSC system comprises both the revised rock suitability criteria and the procedure for the suitability classification during the construction of the repository. The aim of the classification is to avoid such features of the host rock that may be detrimental to the favourable conditions within the repository, either initially or in the long term. This report also discusses the implications of applying the RSC system for the fulfilment of the regulatory requirements concerning the host rock as a natural barrier and the site's overall suitability for hosting a final repository of spent nuclear fuel

  16. NMR study of hydrated calcium silicates; Etude par RMN de la structure des silicates de calcium hydrates

    Energy Technology Data Exchange (ETDEWEB)

    Klur, I

    1996-02-26

    Radioactive wastes storage methods are developed by the CEA. As cements are important materials as well for hours living radioisotopes than for years living radioisotopes, a better knowledge of this material will allow to anticipate its behaviour and to obtain safer storage methods. The structure of calcium silicates (C-S-H) (main constituent of cements) have then been determined in this thesis by nuclear magnetic resonance. This method has allow to explain in structural terms, the different calcium rates that can be measured in the C-S-H too. (O.M.) 101 refs.

  17. Study and installation of concrete shielding in the civil engineering of nuclear construction (1960); Etude et mise en place des betons de protection dans le genie civil des ouvrages nucleaires (1960)

    Energy Technology Data Exchange (ETDEWEB)

    Dubois, F [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    The object of this report is to give technical information about high density concretes which have become very important for radiation biological shielding. The most generally used heavy aggregates (barytes, ilmenite, ferrophosphorus, limonite, magnetite and iron punching) to make these concretes are investigated from the point of view prospecting and physical and chemical characteristics. At first, a general survey of shielding concretes is made involving the study of components, mixing and placing methods, then, a detailed investigation of some high density concretes: barytes concrete, with incorporation of iron punching or iron shot, ferrophosphorus concrete, ilmenite concrete and magnetite concrete, more particularly with regard to grading and mix proportions and testing process. To put this survey in concrete form, two practical designs are described such as they have been carried out at the Saclay Nuclear Station. Specifications are given for diverse concretes and for making the proton-synchrotron 'Saturne' shielding blocks. (author) [French] Ce rapport a pour objet de donner des precisions techniques au sujet des betons a haute densite qui ont pris une grande importance pour la protection biologique contre les rayonnements. Les agregats lourds les plus couramment utilises (barytine, ilmenite, ferrophosphore, limonite, magnetite et riblons) pour la fabrication de ces betons, sont examines du point de vue prospection et caracteristiques physiques et chimiques. On procede d'abord a une etude generale des betons de protection comprenant l'etude des constituants, de la confection et de la mise en place, ensuite, a un examen detaille de quelques betons a haute densite: betons a base de barytine, avec incorporation de riblons ou de grenaille de fonte, betons au ferrophosphore, a base d'ilmenite ou de magnetite, notamment en ce qui concerne la granulometrie, la composition, le dosage et les processus d'essais. Pour concretiser ces etudes, deux applications pratiques

  18. Rocking pneumonia

    OpenAIRE

    Rijkers, Ger T.; Rodriguez Gomez, Maria

    2017-01-01

    Ever since Chuck Berry coined the term “rocking pneumonia” in his 1956 song “Roll over Beethoven”, pneumonia has been mentioned frequently in modern blues and rock songs. We analyzed the lyrics of these songs to examine how various elements of pneumonia have been represented in popular music, specifically the cause of pneumonia, the risk groups, comorbidity (such as the boogie woogie flu), the clinical symptoms, and treatment and outcome. Up to this day, songwriters suggest that pneumonia is ...

  19. Examining the relation between rock mass cuttability index and rock drilling properties

    Science.gov (United States)

    Yetkin, Mustafa E.; Özfırat, M. Kemal; Yenice, Hayati; Şimşir, Ferhan; Kahraman, Bayram

    2016-12-01

    Drilling rate is a substantial index value in drilling and excavation operations at mining. It is not only a help in determining physical and mechanical features of rocks, but also delivers strong estimations about instantaneous cutting rates. By this way, work durations to be finished on time, proper machine/equipment selection and efficient excavation works can be achieved. In this study, physical and mechanical properties of surrounding rocks and ore zones are determined by investigations carried out on specimens taken from an underground ore mine. Later, relationships among rock mass classifications, drillability rates, cuttability, and abrasivity have been investigated using multi regression analysis. As a result, equations having high regression rates have been found out among instantaneous cutting rates and geomechanical properties of rocks. Moreover, excavation machine selection for the study area has been made at the best possible interval.

  20. Rock properties data base

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, R.; Gorski, B.; Gyenge, M.

    1991-03-01

    As mining companies proceed deeper and into areas whose stability is threatened by high and complex stress fields, the science of rock mechanics becomes invaluable in designing underground mine strata control programs. CANMET's Mining Research Laboratories division has compiled a summary of pre- and post-failure mechanical properties of rock types which were tested to provide design data. The 'Rock Properties Data Base' presents the results of these tests, and includes many rock types typical of Canadian mine environments. The data base also contains 'm' and 's' values determined using Hoek and Brown's failure criteria for both pre- and post-failure conditions. 7 refs., 3 tabs., 9 figs., 1 append.

  1. Numerical modelling of fluid-rock interactions: Lessons learnt from carbonate rocks diagenesis studies

    Science.gov (United States)

    Nader, Fadi; Bachaud, Pierre; Michel, Anthony

    2015-04-01

    Quantitative assessment of fluid-rock interactions and their impact on carbonate host-rocks has recently become a very attractive research topic within academic and industrial realms. Today, a common operational workflow that aims at predicting the relevant diagenetic processes on the host rocks (i.e. fluid-rock interactions) consists of three main stages: i) constructing a conceptual diagenesis model including inferred preferential fluids pathways; ii) quantifying the resulted diagenetic phases (e.g. depositing cements, dissolved and recrystallized minerals); and iii) numerical modelling of diagenetic processes. Most of the concepts of diagenetic processes operate at the larger, basin-scale, however, the description of the diagenetic phases (products of such processes) and their association with the overall petrophysical evolution of sedimentary rocks remain at reservoir (and even outcrop/ well core) scale. Conceptual models of diagenetic processes are thereafter constructed based on studying surface-exposed rocks and well cores (e.g. petrography, geochemistry, fluid inclusions). We are able to quantify the diagenetic products with various evolving techniques and on varying scales (e.g. point-counting, 2D and 3D image analysis, XRD, micro-CT and pore network models). Geochemical modelling makes use of thermodynamic and kinetic rules as well as data-bases to simulate chemical reactions and fluid-rock interactions. This can be through a 0D model, whereby a certain process is tested (e.g. the likelihood of a certain chemical reaction to operate under specific conditions). Results relate to the fluids and mineral phases involved in the chemical reactions. They could be used as arguments to support or refute proposed outcomes of fluid-rock interactions. Coupling geochemical modelling with transport (reactive transport model; 1D, 2D and 3D) is another possibility, attractive as it provides forward simulations of diagenetic processes and resulting phases. This

  2. Evaluation of dynamic characteristics of hard rock based on numerical simulations of in situ rock tests

    International Nuclear Information System (INIS)

    Yamagami, Yuya; Ikusada, Koji; Jiang, Yujing

    2009-01-01

    In situ rock tests of hard rock of conglomerate in which discontinuities in high angle are dominant were conducted. In this study, in order to confirm the validity of the test results and the test condition, and in order to elucidate the deformation behaviour and the mechanism of shear strength of the rock mass, the numerical simulations of the in situ rock tests by using distinct element method were performed. As a result, it was clarified that the behaviour of the rock mass strongly depends on both geometrical distribution of discontinuities and those mechanical properties. It is thought that a series of evaluation processes showed in this study contribute to improve the reliability of the dynamic characteristic evaluation of the rock mass. (author)

  3. Soil/Rock Properties Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — Soil/Rock Properties LaboratoryLocation: Spokane SiteThe Soil/Rock Properties Laboratory is contained in the soils bay, a 4,700 sq. ft. facility that provides space...

  4. Rock Cycle Roulette.

    Science.gov (United States)

    Schmidt, Stan M.; Palmer, Courtney

    2000-01-01

    Introduces an activity on the rock cycle. Sets 11 stages representing the transitions of an earth material in the rock cycle. Builds six-sided die for each station, and students move to the stations depending on the rolling side of the die. Evaluates students by discussing several questions in the classroom. Provides instructional information for…

  5. Igneous rocks formed by hypervelocity impact

    Science.gov (United States)

    Osinski, Gordon R.; Grieve, Richard A. F.; Bleacher, Jacob E.; Neish, Catherine D.; Pilles, Eric A.; Tornabene, Livio L.

    2018-03-01

    Igneous rocks are the primary building blocks of planetary crusts. Most igneous rocks originate via decompression melting and/or wet melting of protolith lithologies within planetary interiors and their classification and compositional, petrographic, and textural characteristics, are well-studied. As our exploration of the Solar System continues, so too does the inventory of intrusive and extrusive igneous rocks, settings, and processes. The results of planetary exploration have also clearly demonstrated that impact cratering is a ubiquitous geological process that has affected, and will continue to affect, all planetary objects with a solid surface, whether that be rock or ice. It is now recognized that the production of igneous rocks is a fundamental outcome of hypervelocity impact. The goal of this review is to provide an up-to-date synthesis of our knowledge and understanding of igneous rocks formed by hypervelocity impact. Following a brief overview of the basics of the impact process, we describe how and why melts are generated during impact events and how impact melting differs from endogenic igneous processes. While the process may differ, we show that the products of hypervelocity impact can share close similarities with volcanic and shallow intrusive igneous rocks of endogenic origin. Such impact melt rocks, as they are termed, can display lobate margins and cooling cracks, columnar joints and at the hand specimen and microscopic scale, such rocks can display mineral textures that are typical of volcanic rocks, such as quench crystallites, ophitic, porphyritic, as well as features such as vesicles, flow textures, and so on. Historically, these similarities led to the misidentification of some igneous rocks now known to be impact melt rocks as being of endogenic origin. This raises the question as to how to distinguish between an impact versus an endogenic origin for igneous-like rocks on other planetary bodies where fieldwork and sample analysis may not

  6. Transporting radioactive rock

    International Nuclear Information System (INIS)

    Pearce, G.

    1990-01-01

    The case is made for exempting geological specimens from the IAEA Regulations for Safer Transport of Radioactive Materials. It is pointed out that many mineral collectors in Devon and Cornwall may be unwittingly infringing these regulations by taking naturally radioactive rocks and specimens containing uranium ores. Even if these collectors are aware that these rocks are radioactive, and many are not, few have the necessary equipment to monitor the activity levels. If the transport regulations were to be enforced alarm could be generated and the regulations devalued in case of an accident. The danger from a spill of rock specimens is negligible compared with an accident involving industrial or medical radioactive substances yet would require similar special treatment. (UK)

  7. Preliminary study of the preparation of uranium 232 by irradiation of protactinium 231; Etude preliminaire a la preparation d'uranium 232 par irradiation de protactinium 231

    Energy Technology Data Exchange (ETDEWEB)

    Guillot, Ph. [Commissariat a l' Energie Atomique, Fontenay aux Roses (France). Centre d' Etudes Nucleaires

    1965-07-01

    A bibliography about preparation of uranium 232 is done. This even-even isotope of uranium is suitable for radioactive tracer, neutron source through {alpha},n reaction and heat source applications. The irradiation of protactinium 231, the chemical separation and the purification of uranium are studied. (author) [French] Une etude bibliographique de la preparation d'uranium 232 a ete effectuee. Cet isotope pair-pair de l'uranium peut etre utilise en tant que traceur, source d'energie et source de neutrons, lorsqu'il est melange a un element leger tel le beryllium. Une etude du taux de formation des isotopes produits, lors de l'irradiation du protactinium 231 - une des manieres d'obtenir l'uranium 232 - a ete faite a l'aide d'un programme passe sur ordinateur. Les problemes poses par la separation chimique et la purification de l'uranium ont ete egalement envisages dans ce rapport. (auteur)

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

    Science.gov (United States)

    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.

  9. The ultrasonic copper and brass decontamination study; Etude de la decontamination du cuivre et des laitons en presence d'ultra-sons

    Energy Technology Data Exchange (ETDEWEB)

    Courtault, J; Kerdelleau, J de; Mestre, E [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1965-07-01

    The use of ultra-sounds as a decontamination technic does not bring an absolute solution. As a function of the materials it seemed necessary to find what was the optimum conditions for using the ultra-sounds and to define not only the ultra-sonic factors but also the chemical solutions which bring some appreciable decontamination factors without bringing any too important corrosion processus. This report gives the results of this study applied to copper and brass. This study allowed to select some effective treatment baths on the two types of contamination: plutonium and fission products. (authors) [French] L'emploi des ultra-sons comme technique de decontamination n'amene pas une solution absolue. Il est apparu necessaire de rechercher en fonction de la nature du materiau a decontaminer quelles etaient les conditions optimales d'utilisation des ultra-sons et de definir alors non seulement les facteurs ultrasoniques mais encore les solutions chimiques qui apportent des facteurs de decontamination appreciables sans amener des phenomenes de corrosion trop importants. Ce rapport donne les resultats de cette etude appliquee au cuivre et aux laitons. Cette etude a permis de selectionner des bains de traitement efficaces dans les deux cas de contamination: plutonium et produits de fission. (auteurs)

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

    Science.gov (United States)

    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 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.

  11. The analysis of creep characteristics of the surrounding rock of the carbonaceous rock tunnel based on Singh-Mitchell model

    Science.gov (United States)

    Luo, Junhui; Mi, Decai; Ye, Qiongyao; Deng, Shengqiang; Zeng, Fuquan; Zeng, Yongjun

    2018-01-01

    Carbonaceous rock has the characteristics of easy disintegration, softening, swelling and environmental sensitivity, which belongs to soft surrounding rock, and the deformation during excavation and long-term stability of the surrounding rock of carbonaceous rock tunnel are common problems in the construction of carbonaceous rock tunnel. According to the above, the Monitor and measure the displacement, temperature and osmotic pressure of the surrounding carbonaceous rock of the tunnel of Guangxi Hebai highway. Then it based on the obtaining data to study the creep mechanism of surrounding rock using Singh-Mitchell model and predict the deformation of surrounding rock before the tunnel is operation. The results show that the Singh-Mitchell creep model can effectively analyse and predict the deformation development law of surrounding rock of tunnel without considering temperature and osmotic pressure, it can provide reference for the construction of carbonaceous rock tunnel and the measures to prevent and reinforce it..

  12. Experimental Rock-on-Rock Abrasive Wear Under Aqueous Conditions: its Role in Subglacial Abrasion

    Science.gov (United States)

    Rutter, E. H.; Lee, A. G.

    2003-12-01

    We have determined experimentally the rate of abrasive wear of rock on rock for a range of rock types as a function of normal stress and shear displacement. Unlike abrasive wear in fault zones, where wear products accumulate as a thickening gouge zone, in our experiments wear particles were removed by flowing water. The experiments are thus directly pertinent to one of the most important processes in subglacial erosion, and to some extent in river incision. Wear was produced between rotating discs machined from rock samples and measured from the progressive approach of the disc axes towards each other under various levels of normal load. Shear displacements of several km were produced. Optical and scanning electron microscopy were used to study the worn rock surfaces, and particle size distributions in wear products were characterized using a laser particle size analyzer. Rock types studied were sandstones of various porosities and cement characteristics, schists and a granite. In all cases abrasion rate decreased logarithmically with displacement by up to 2 orders of magnitude until a steady state was approached, but only after at least 1 km displacement. The more porous, less-well cemented rocks wore fastest. Amount of abrasion could be characterized quantitatively using an exponentially decaying plus a steady-state term. Wear rate increased non-linearly with normal contact stress, apparently to an asymptote defined by the unconfined compressive strength. Microstructural study showed that the well-cemented and/or lowest porosity rocks wore by progressive abrasion of grains without plucking, whereas whole grains were plucked out of weakly-cemented and/or more porous rocks. This difference in behavior was reflected in wear-product particle size distributions. Where whole-grain plucking was possible, wear products were dominated by particles of the original grain size rather than finer rock flour. Comparison of our results to glacier basal abrasive wear estimated

  13. Solid as a rock

    International Nuclear Information System (INIS)

    Pincus, H.J.

    1984-01-01

    Recent technologic developments have required a more comprehensive approach to the behavior of rock mass or rock substance plus discontinuities than was adequate previously. This work considers the inherent problems in such operations as the storage of hot or cold fluids in caverns and aquifers, underground storage of nuclear waste, underground recovery of heat from hydrocarbon fuels, tertiary recovery of oil by thermal methods, rapid excavation of large openings at shallow to great depths and in hostile environments, and retrofitting of large structures built on or in rock. The standardization of methods for determining rock properties is essential to all of the activities described, for use not only in design and construction but also in site selection and post-construction monitoring. Development of such standards is seen as a multidisciplinary effort

  14. The physical principles of rock magnetism

    CERN Document Server

    Stacey, Frank

    1974-01-01

    Developments in Solid Earth Geophysics 5: The Physical Principles of Rock Magnetism explores the physical principles of rock magnetism, with emphasis on the properties of finely divided magnetic materials. It discusses the origin and stability of rock magnetizations, the role of remanent magnetism in interpreting magnetic surveys, magnetic anisotropy as an indicator of rock fabric, and the relationship between piezomagnetic changes and seismic activity. Organized into 13 chapters, this volume discusses the properties of solids, magnetite and hematite grains, and rocks with magnetite grains

  15. 30 CFR 57.3461 - Rock bursts.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Rock bursts. 57.3461 Section 57.3461 Mineral...-Underground Only § 57.3461 Rock bursts. (a) Operators of mines which have experienced a rock burst shall— (1) Within twenty four hours report to the nearest MSHA office each rock burst which: (i) Causes persons to...

  16. Sorption of cesium in intact rock

    International Nuclear Information System (INIS)

    Puukko, E.

    2014-04-01

    The mass distribution coefficient K d is used in performance assessment (PA) to describe sorption of a radionuclide on rock. The R d is determined using crushed rock which causes uncertainty in converting the R d values to K d values for intact rock. This work describes a method to determine the equilibrium of sorption on intact rock. The rock types of the planned Olkiluoto waste disposal site were T-series mica gneiss (T-MGN), T-series tonalite granodiorite granite gneiss (T-TGG), P-series tonalite granodiorite granite gneiss (P-TGG) and pegmatitic granite (PGR). These rocks contain different amount of biotite which is the main sorbing mineral. The sorption of cesium on intact rock slices was studied by applying an electrical field to speed up migration of cesium into the rock. Cesium is in the solution as a noncomplex cation Cs + and it is sorbed by ion exchange. The tracer used in the experiments was 134 Cs. The experimental sorption on the intact rock is compared with values calculated using the in house cation exchange sorption model (HYRL model) in PHREEQC program. The observed sorption on T-MGN and T-TGG rocks was close to the calculated values. Two PGR samples were from a depth of 70 m and three samples were from a depth of 150 m. Cesium sorbed more than predicted on the two 70 m PGR samples. The sorption of Cs on the three 150 m PGR samples was small which was consistent with the calculations. The pegmatitic granite PGR has the smallest content of biotite of the four rock types. In the case of P-TGG rock the observed values of sorption were only half of the calculated values. Two kind of slices were cut from P-TGG drill core. The slices were against and to the direction of the foliation of the biotite rims. The sorption of cesium on P-TGG rock was same in both cases. The results indicated that there was no effect of the directions of the electric field and the foliation of biotite in the P-TGG rock. (orig.)

  17. A new method to test rock abrasiveness based on physico-mechanical and structural properties of rocks

    Directory of Open Access Journals (Sweden)

    V.N. Oparin

    2015-06-01

    Full Text Available A new method to test rock abrasiveness is proposed based upon the dependence of rock abrasiveness on their structural and physico-mechanical properties. The article describes the procedure of presentation of properties that govern rock abrasiveness on a canonical scale by dimensionless components, and the integrated estimation of the properties by a generalized index. The obtained results are compared with the known classifications of rock abrasiveness.

  18. Study of thermocouples for control of high temperatures; Etude de thermocouples pour le reperage des hautes temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Villamayor, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Faculte des Sciences de l' Universite de Lyon - 69 (France)

    1967-07-01

    Previous works have shown that the tungsten-rhenium alloys thermocouples were a good instrument for control of high temperatures. From its, the author has studied the W/W 26 per cent and W 5 per cent Re/W 26 per cent Re french manufactured thermocouples and intended for control of temperatures in nuclear reactors until 2300 deg. C. In 'out-pile' study he determines the general characteristics of these thermocouples: average calibration curves, thermal shocks influence, response times, and alloys allowing the cold source compensation. The evolution of these thermocouples under thermal neutron flux has been determined by 'in-pile' study. The observations have led the author to propose a new type of thermocouples settled of molybdenum-columbium alloys. (author) [French] Des travaux anterieurs ont montre que les thermocouples des alliages tungstene-rhenium etaient susceptibles de reperer avec precision des hautes temperatures. A partir de la, l'auteur a etudie las thermocouples W/W 26 pour cent Re et W 5 pour cent Re/W 26 pour cent Re de fabrication francaise et destines au controle des temperatures dans les reacteurs nucleaires, jusqu'a 2300 deg. C Dans l'etude 'hors-pile' il a determine les caracteristiques generales de ces thermocouples: courbes d'etalonnage moyen, influence des chocs thermiques, temps de reponse, et alliages assurant la compensation de soudure froide. L'etude 'en-pile' a permis de rendre compte de l'evolution de ces thermocouples sous flux neutroniques. Les phenomenes observes ont conduit l'auteur a proposer un nouveau type de thermocouples constitues d'alliages molybdene-niobium. (auteur)

  19. Structure par RMN d'un complexe AlcR(1-60)-ADN: Reconnaissance du petit sillon par la partie N-terminale

    Science.gov (United States)

    Cahuzac, B.; Félenbok, B.; Guittet, E.

    1999-10-01

    Aspergillus nidulans is a filamentous fungus able to use ethanol as sole energy source. The activation of the ethanol regulon genes expression is mediated by the AlcR protein. Its DNA-binding domain is located in the N-terminus (residues 1 to 60), and its NMR solution structure shows a global zinc binuclear cluster fold, with two helices in addition to the basic binuclear motif. A small number of crystallographic structures of DNA complexes of binuclear cluster proteins is yet known, and points out the major groove and the first helix as the principal sites of interaction on the DNA and the protein respectively. In this article we show evidences that the N-terminus of the protein is involved in binding to the minor groove. Aspergillus nidulans est un champignon filamenteux capable d'utiliser l'éthanol comme source unique d'énergie. La protéine AlcR est responsable de l'activation de l'expression des gènes du régulon éthanol. Le domaine de liaison à l'ADN est situé dans la partie N-terminale de la protéine (a.a. 1 à 60), et sa structure déterminée par RMN en solution montre un repliement global en bouquet binucléaire à zinc, avec deux hélices supplémentaires par rapport au motif de base. Alors que les structures déjà connues de complexes ADN - bouquets binucléaires permettent de situer dans le grand sillon la quasi-totalité des interactions, nous montrons dans la présente étude l'implication du début de la séquence dans la reconnaissance du petit sillon de l'ADN (a.a. 5 et 6).

  20. Study of {gamma}'s in Naiade; Etude des gamma de Naiade

    Energy Technology Data Exchange (ETDEWEB)

    Millot, J P; Rastoin, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    Following a study of the gamma sources, the flux of gamma of different energies in the swimming pool is investigated. The biological dose can thus be obtained by calculation, and compared with the results given by photographic plates. The influence of photoneutrons is estimated by calculation, and research is being carried out on their influence on the thermal neutron flux curve on the axis of the uranium plate, with the plate emitting neutrons and with the plate protected by boral. (author) [French] Apres l'etude des sources de gamma, l'on etudie le flux de gamma de differentes energies dans la piscine. La dose biologique peut etre obtenue ainsi par le calcul et comparee avec les resultats donnes par les plaques photographiques. L'influence des photoneutrons est estimee par le calcul et l'on recherche leur influence sur la courbe de flux de neutrons thermiques sur l'axe de la plaque d'uranium, la plaque emettant des neutrons et la plaque protegee par du boral. (auteur)

  1. Measurements of thermal properties of rocks

    International Nuclear Information System (INIS)

    Kumada, Toshiaki

    2001-02-01

    The report concerns the measurement of thermal conductivity and specific heat of supplied sedimental rock B and Funyu rock. The method of measurement of these properties was done with the method which was developed at 1997 and improved much in its accuracy by the present author et al. The porosity of sedimental rock B is 0.55, which is deduced from the density of rock (the porosity deduced from the difference between dry and water filled conditions is 0.42) and the shape and size of pores in rock are much different. Its thermal conductivity is 0.238 W/mK in dry and 1.152 W/mK in water filled conditions respectively, while the thermal conductivity of bentonite is 0.238 W/mK in dry and 1.152 W/mK in water saturated conditions. The difference of thermal conductivity between dry and water saturated conditions is little difference in sedimental rock B and bentonite at same porosity. The porosity of Funyu rock is 0.26 and the shape and size of pores in the rock are uniform. Its thermal conductivity is 0.914 W/mK in dry and 1.405 W/mK in water saturated conditions, while the thermal conductivity of bentonite is 0.606 W/mK in dry and 1.591 W/mK in water saturated conditions respectively. The correlation estimating thermal conductivity of rocks was derived based on Fricke correlation by presuming rocks as a suspension. (author)

  2. A crystallographic and spectroscopic study of crystal sites in the 'spinel' structure; Etude cristallographique et spectroscopique des sites cristallins dans la structure 'spinelle'

    Energy Technology Data Exchange (ETDEWEB)

    Drifford, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1967-06-15

    A crystallographic study on magnesium aluminates led to the determination of crystal site average distortion. A spectroscopic study of transition elements doped spinels gave the position of the doping element in tetrahedral (A) or octahedral (B) sites, and the local distortion of the latter. The comparison of average and local parameters points to differences in the behaviour of doping elements and shows the size of (A) sites are independent of the host crystal composition while the average size of (B) sites varies with the composition. (author) [French] Une etude cristallographique des aluminates de magnesium a permis de determiner la deformation moyenne des sites cristallins. Une etude spectroscopique des aluminates de magnesium dopes avec des elements de transition a permis de localiser les dopants entre les sites tetraedriques (A) et octaedriques (B) et d'etudier la deformation locale de ces sites. La comparaison entre les parametres moyens et locaux a caracterise le comportement du dopant et montre que les dimensions des sites (A) sont independantes de la composition de la matrice, alors que les caracteristiques geometriques moyennes des sites (B) varient continument avec la composition. (auteur)

  3. Multiverso: Rock'n'Astronomy

    Science.gov (United States)

    Caballero, J. A.

    2012-05-01

    In the last few years, there have been several projects involving astronomy and classical music. But have a rock band ever appeared at a science conference or an astronomer at a rock concert? We present a project, Multiverso, in which we mix rock and astronomy, together with poetry and video art (Caballero, 2010). The project started in late 2009 and has already reached tens of thousands people in Spain through the release of an album, several concert-talks, television, radio, newspapers and the internet.

  4. Rock Pore Structure as Main Reason of Rock Deterioration

    Directory of Open Access Journals (Sweden)

    Ondrášik Martin

    2014-03-01

    Full Text Available Crashed or dimensional rocks have been used as natural construction material, decoration stone or as material for artistic sculptures. Especially old historical towns not only in Slovakia have had experiences with use of stones for construction purposes for centuries. The whole buildings were made from dimensional stone, like sandstone, limestone or rhyolite. Pavements were made especially from basalt, andesite, rhyolite or granite. Also the most common modern construction material - concrete includes large amounts of crashed rock, especially limestone, dolostone and andesite.

  5. Study of radio-active ions in the atmosphere; Etude des ions radioactifs de l'atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Renoux, A [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1965-01-01

    A comparative study is made of active, deposits of radon and thoron in suspension in the atmosphere by means of {alpha} radiation counting, using ZELENY tubes, scattering equipment, filter papers or membranes. It has been possible to show the existence of small and large ions which are negative and positive, as well as of neutral radio-active nuclei; their properties are studied. A theoretical interpretation of the results is presented. The average content of radon (using the Ra A concentration) and of Th B in the air has been determined. The radioactive equilibrium between radon and its daughter products in atmospheric air are examined. The techniques developed for active radon and thoron deposits are applied to the study of artificial radio-activity, the analyses being carried out by means of {gamma} spectrometry. (author) [French] On effectue une etude comparative entre les depots actifs du radon et du thoron en suspension dont l'atmosphere a l'aide de comptages de rayonnement {alpha}, en utilisant des tubes de ZELENY, une batterie de diffusion, des papiers filtres ou des membranes. On met ainsi en evidence la presence de petits et gros ions negatifs et positifs, ainsi que celle de noyaux neutres radioactifs, et on etudie leurs proprietes. Une Interpretation theorique des resultats obtenus est developpee. On determine la teneur moyenne de l'air en radon (a partir de la concentration en Ra A) et en Th B. L'equilibre radioactif entre le radon et ses descendants, dans l'air atmospherique, est examine. Les Techniques mises au point pour les depots actifs du radon et du thoron sont appliquees a l'etude de la radioactivite artificielle, les depouillements s'effectuant par spectrometrie {gamma}. (auteur)

  6. Strength Assessment of Broken Rock Postgrouting Reinforcement Based on Initial Broken Rock Quality and Grouting Quality

    Directory of Open Access Journals (Sweden)

    Hongfa Xu

    2017-01-01

    Full Text Available To estimate postgrouting rock mass strength growth is important for engineering design. In this paper, using self-developed indoor pressure-grouting devices, 19 groups of test cubic blocks were made of the different water cement ratio grouting into the broken rock of three kinds of particle sizes. The shear strength parameters of each group under different conditions were tested. Then this paper presents a quantitative calculation method for predicting the strength growth of grouted broken rock. Relational equations were developed to investigate the relationship between the growth rates of uniaxial compressive strength (UCS, absolute value of uniaxial tensile strength (AUTS, internal friction angle, and cohesion for post- to pregrouting broken rock based on Mohr-Coulomb strength criterion. From previous test data, the empirical equation between the growth rate of UCS and the ratio of the initial rock mass UCS to the grout concretion UCS has been determined. The equations of the growth rates of the internal friction coefficient and UCS for grouting broken rock with rock mass rating (RMR and its increment have been established. The calculated results are consistent with the experimental results. These observations are important for engineered design of grouting reinforcement for broken rock mass.

  7. Etude de la transition ferroelectrique-ferroelastique du KD2PO4 forme du front de phase en fonction du gradient thermique

    OpenAIRE

    Kvítek, Zdeněk

    2010-01-01

    Etude de la transition ferroelectrique-ferroelastique du KD2PO4 forme du front de phase en fonction du gradient thermique The thesis explores complex process of first order transition of KD2PO4 crystal from tetragonal phase to ferroelectric - ferroelastic orthorhombic phase and back at temperature 209 K. The experimental set up of nitrogeneous cryostat allowes temperature and temperature gradient variations during simultaneous three axes optical sample observations, dielectric measurements. T...

  8. Rock slope design guide.

    Science.gov (United States)

    2011-04-01

    This Manual is intended to provide guidance for the design of rock cut slopes, rockfall catchment, and : rockfall controls. Recommendations presented in this manual are based on research presented in Shakoor : and Admassu (2010) entitled Rock Slop...

  9. Rock Slope Design Criteria

    Science.gov (United States)

    2010-06-01

    Based on the stratigraphy and the type of slope stability problems, the flat lying, Paleozoic age, sedimentary : rocks of Ohio were divided into three design units: 1) competent rock design unit consisting of sandstones, limestones, : and siltstones ...

  10. Source rock potential of middle cretaceous rocks in Southwestern Montana

    Science.gov (United States)

    Dyman, T.S.; Palacas, J.G.; Tysdal, R.G.; Perry, W.J.; Pawlewicz, M.J.

    1996-01-01

    The middle Cretaceous in southwestern Montana is composed of a marine and nonmarine succession of predominantly clastic rocks that were deposited along the western margin of the Western Interior Seaway. In places, middle Cretaceous rocks contain appreciable total organic carbon (TOC), such as 5.59% for the Mowry Shale and 8.11% for the Frontier Formation in the Madison Range. Most samples, however, exhibit less than 1.0% TOC. The genetic or hydrocarbon potential (S1+S2) of all the samples analyzed, except one, yield less than 1 mg HC/g rock, strongly indicating poor potential for generating commercial amounts of hydrocarbons. Out of 51 samples analyzed, only one (a Thermopolis Shale sample from the Snowcrest Range) showed a moderate petroleum potential of 3.1 mg HC/g rock. Most of the middle Cretaceous samples are thermally immature to marginally mature, with vitrinite reflectance ranging from about 0.4 to 0.6% Ro. Maturity is high in the Pioneer Mountains, where vitrinite reflectance averages 3.4% Ro, and at Big Sky Montana, where vitrinite reflectance averages 2.5% Ro. At both localities, high Ro values are due to local heat sources, such as the Pioneer batholith in the Pioneer Mountains.

  11. Impact of grain size and rock composition on simulated rock weathering

    Science.gov (United States)

    Israeli, Yoni; Emmanuel, Simon

    2018-05-01

    Both chemical and mechanical processes act together to control the weathering rate of rocks. In rocks with micrometer size grains, enhanced dissolution at grain boundaries has been observed to cause the mechanical detachment of particles. However, it remains unclear how important this effect is in rocks with larger grains, and how the overall weathering rate is influenced by the proportion of high- and low-reactivity mineral phases. Here, we use a numerical model to assess the effect of grain size on chemical weathering and chemo-mechanical grain detachment. Our model shows that as grain size increases, the weathering rate initially decreases; however, beyond a critical size no significant decrease in the rate is observed. This transition occurs when the density of reactive boundaries is less than ˜ 20 % of the entire domain. In addition, we examined the weathering rates of rocks containing different proportions of high- and low-reactivity minerals. We found that as the proportion of low-reactivity minerals increases, the weathering rate decreases nonlinearly. These simulations indicate that for all compositions, grain detachment contributes more than 36 % to the overall weathering rate, with a maximum of ˜ 50 % when high- and low-reactivity minerals are equally abundant in the rock. This occurs because selective dissolution of the high-reactivity minerals creates large clusters of low-reactivity minerals, which then become detached. Our results demonstrate that the balance between chemical and mechanical processes can create complex and nonlinear relationships between the weathering rate and lithology.

  12. Epigenetic alterations of sedimentary rocks at deposits

    International Nuclear Information System (INIS)

    Komarova, G.V.; Kondrat'eva, I.A.; Zelenova, O.I.

    1980-01-01

    Notions are explained, and technique for studying epigenetic alterations of sedimentary rocks at uranium deposits is described. Main types of epigenetic transformations and their mineralogic-geochemical characteristics are considered. Rock alterations, accompanying uranium mineralization, can be related to 2 types: oxidation and reduction. The main mineralogic-geochemical property of oxidation transformations is epigenetic limonitization. Stratal limonitization in primary grey-coloured terrigenic rocks and in epigenetically reduced (pyritized) rocks, as well as in rock, subjected to epigenetic gleying, are characterized. Reduction type of epigenetic transformations is subdivided into sulphidic and non-sulphidic (gley) subtypes. Sulphidic transformations in grey-coloured terrigenic rocks with organic substance of carbonic row, in rocks, containing organic substance of oil row, sulphide transformations of sedimentary rocks, as well as gley transformations, are considered

  13. Baby fission chambers; Etude de chambres a fission miniatures

    Energy Technology Data Exchange (ETDEWEB)

    Guery, U; Tachon, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1957-07-01

    The present report is intended, on the one band, as a study of the main types of fission chambers produced to date, and on the other, to deal more generally with this type of detector. Originally, it was with a view to the charting of neutron scatter in 'Proserpine' that the authors undertook the study of these chambers. During the course of the task, it was considered worth tbe trouble of developing its scope to include a more general application: neutron scatter measurement of various energy neutrons within a reduced volume with slight local disturbance. (author) [French] Le present rapport se propose, d'une part, d'exposer les principales realisations de chambres a fission, d'autre part de faire une mise au point a caractere plus general sur ces detecteurs. Au depart, c'est surtout en vue des mesures de densite neutronique dans 'Proserpine' que les auteurs ont etudie ces chambres; au cours de la mise au point, il a paru interessant de developper leur etude pour des applications plus generales: mesures de densites de neutrons de differentes energies dans un element de volume tres reduit et avec faible perturbation locale. (auteur)

  14. Alecto 2 - interaction studies; Alecto 2 - etudes d'interaction

    Energy Technology Data Exchange (ETDEWEB)

    Brunet, J P; Clouet d' Orval, Ch; Mougniot, J C; Penet, F [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1965-07-01

    Weak interactions were experimentally studies with the tank of the critical assembly Alecto II and one, two or three bottles containing solutions of various concentrations. In particular, was studied the validity of certain classical assumptions, shielding effects, screening and semi-reflexion effects, importance of thermal coupling. The method of the 'k{sub eff}, solid angle' is shown to apply to such a system. The determination by divergence and pulsed neutron technique of the reactivity related to a millimeter of solution level affords the obtention of critical heights in terms of reactivity. (authors) [French] Une etude experimentale d'interactions faibles a ete faite entre la cuve de l'experience critique ALECTO II et une, deux ou trois bouteilles contenant des concentrations variees. On etudie, en particulier, la validite de certaines hypotheses classiques, effets d'ombre, d'ecrans, de semi-reflexion, importance du couplage thermique. On montre d'autre part que la methode du 'K{sub eff}, angle solide' peut s'appliquer a un tel systeme. La determination par divergence et neutrons pulses de la reactivite liee au millimetre de solution permet de traduire les hauteurs critiques obtenues, en terme de reactivite. (auteurs)

  15. Study of the {sup 14}C benzimidazole distribution in mice after inter-peritoneal injection; Etude de la repartition du benzimidazole {sup 14}C chez la souris apres injection intraperitoneale

    Energy Technology Data Exchange (ETDEWEB)

    Tyortyalian, C [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1965-07-01

    In order to provide further information on the mechanism of benzimidazole radioprotective activity, this work studies the tissual repartition in mice of this compound labelled with carbon 14. Experiments have showed that benzimidazole distribution is fast and homogeneous in all the tissues, but however affinity appears at the level of stomach and gastric content. Elimination is made through the urinary system and is very fast. (author) [French] Dans le cadre de l'etude du mecanisme de l'action radioprotectrice du benzimidazole, ce travail a pour objet l'etude de la repartition tissulaire chez la souris de ce compose marque au carbone 14. L'experimentation a montre que le benzimidazole se repartit tres rapidement et de facon pratiquement homogene dans tous les tissus, avec toutefois une affinite paraissant se manifester au niveau de l'estomac et du contenu gastrique. L'elimination, qui se fait par voie urinaire, est tres rapide. (auteur)

  16. Development of a gas-ionization {beta}-spectrometer; Etude et realisation d'un spectrometre {beta} a ionisation gazeuse

    Energy Technology Data Exchange (ETDEWEB)

    Le Du, R [Commissariat a l' Energie Atomique, Bruyeres-le-Chatel (France). Centre d' Etudes

    1968-05-15

    We intend to develop in our laboratory a {beta}-spectrometer. This apparatus will have two main objectives: 1 - the determination of the nature and the degree of purity of certain {beta}-emitting radioactive substances; 2 - the study of an activity calibration process for {beta}-emitting radioactive sources. (author) [French] Nous nous proposons d'etudier et de realiser dans notre laboratoire un spectrometre {beta}. Cet appareil aura deux buts principaux: 1 - determiner la nature et le degre de purete de certains corps radioactifs emetteurs {beta}; 2 - permettre l'etude d'un procede d'etalonnage en activite de sources radioactives emetteurs {beta}. (auteur)

  17. Weathering of rock 'Ginger'

    Science.gov (United States)

    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).

  18. An investigation of rock fall and pore water pressure using LIDAR in Highway 63 rock cuts.

    Science.gov (United States)

    2014-07-01

    The purpose of this research work is compare LIDAR scanning measurements of rock fall with the natural changes in groundwater level to determining the effect of water pressures (levels) on rock fall. To collect the information of rock cut volume chan...

  19. Multicenter, randomized comparison between magnetically navigated and manually guided radiofrequency ablation of atrioventricular nodal reentrant tachycardia (the MagMa-AVNRT-trial).

    Science.gov (United States)

    Reents, Tilko; Jilek, Clemens; Schuster, Peter; Nölker, Georg; Koch-Büttner, Katharina; Ammar-Busch, Sonia; Semmler, Verena; Bourier, Felix; Kottmaier, Marc; Kornmayer, Marie; Brooks, Stephanie; Fichtner, Stephanie; Kolb, Christof; Deisenhofer, Isabel; Hessling, Gabriele

    2017-12-01

    Remote magnetic navigation (RMN) is attributed to diminish radiation exposure for both patient and operator performing catheter ablation for different arrhythmia substrates. The purpose of this prospective, randomized study was to compare RMN with manually guided catheter ablation for AV nodal reentrant tachycardia (AVNRT) regarding fluoroscopy time/dosage, acute and long-term efficacy as well as safety. A total of 218 patients with AVNRT undergoing catheter ablation at three centers (male 34%, mean age 50 ± 17 years) were randomized to a manual approach (n = 113) or RMN (n = 105) using the Niobe ® magnetic navigation system. The primary study endpoint was total fluoroscopy time/dosage for patient and operator at the end of the procedure. Secondary endpoints included acute success, procedure duration, complications and success rate after 6 months. Fluoroscopy time and dosage for the patient were significantly reduced in the RMN group compared to the manual group (6 ± 6 vs. 11 ± 10 min; p < 0.001 and 425 ± 558 vs. 751 ± 900 cGycm 2 , p = 0.002). A reduction in fluoroscopy time/dose also applied to the operator (3 ± 5 vs. 7 ± 9 min 209 ± 444 vs. 482 ± 689 cGycm 2 , p < 0.001). Procedure duration was significantly longer in the RMN group (88 ± 29 vs. 79 ± 29 min; p = 0.03) and crossover from the RMN group to manual ablation occurred in 7.6% of patients (7.6 vs. 0.1%; p = 0.02). Acute success was achieved in 100% of patients in both groups. Midterm success after 6 months was 97 vs. 98% (p = 0.67). No complications occurred in both groups. The use of RMN for catheter ablation of AVNRT compared to a manual approach results in a reduction of fluoroscopy time and dosage of about 50% for both patients and physicians. Acute and midterm success and safety are comparable. RMN is a good alternative to a manual approach for AVNRT ablation.

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

    Science.gov (United States)

    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

  1. Soft Rock Yields Clues to Mars' Past

    Science.gov (United States)

    2004-01-01

    [figure removed for brevity, see original site] Figure 1 This image taken by the Mars Exploration Rover Spirit shows the rock outcrop dubbed 'Clovis.' The rock was discovered to be softer than other rocks studied so far at Gusev Crater after the rover easily ground a hole into it with its rock abrasion tool. Spirit's solar panels can be seen in the foreground. This image was taken by the rover's navigation camera on sol 205 (July 31, 2004). Elemental Trio Found in 'Clovis' Figure 1 above shows that the interior of the rock dubbed 'Clovis' contains higher concentrations of sulfur, bromine and chlorine than basaltic, or volcanic, rocks studied so far at Gusev Crater. The data were taken by the Mars Exploration Rover Spirit's alpha particle X-ray spectrometer after the rover dug into Clovis with its rock abrasion tool. The findings might indicate that this rock was chemically altered, and that fluids once flowed through the rock depositing these elements.

  2. Effects of explosions in hard rocks

    International Nuclear Information System (INIS)

    Heuze, F.E.; Walton, O.R.; Maddix, D.M.; Shaffer, R.J.; Butkovich, T.R.

    1993-01-01

    This work relates to explosions in hard rocks (ex: basalt, granite, limestone...). Hard rock masses typically have a blocky structure created by the existence of geologic discontinuities such as bedding contacts, faults, and joints. At very high pressure - hundreds of kilobars and above - these discontinuities do not act separately, and the rock appears to be an equivalent continuous medium. At stress of a few tens of kilobars and below, the geologic discontinuities control the kinematics of the rock masses. Hence, the simulation of rock dynamics, anywhere but in the very-near source region, should account for those kinematics

  3. Isotope shifting capacity of rock

    International Nuclear Information System (INIS)

    Blattner, P.; Department of Scientific and Industrial Research, Lower Hutt

    1980-01-01

    Any oxygen isotope shifted rock volume exactly defines a past throughput of water. An expression is derived that relates the throughput of an open system to the isotope shift of reservoir rock and present-day output. The small isotope shift of Ngawha reservoir rock and the small, high delta oxygen-18 output are best accounted for by a magmatic water source

  4. Thermal conductivity of the rocks in the Bureau of Mines Standard Rock Suite

    International Nuclear Information System (INIS)

    Morgan, M.T.; West, G.A.

    1980-01-01

    Thermal conductivities of eight rocks from the Bureau of Mines Standard Rock Suite were measured in air over the temperature range 373 to 533 0 K (100 to 260 0 C). The thermal conductivities of these rocks were measured to furnish standards for future comparisons with host rock from prospective nuclear waste repository sites. The thermal conductivity at a given temperature decreased by as much as 9% after a specimen had been heated to the maximum temperature (533 0 K), but additional heating cycles had no further effect. This decrease was smallest in the igneous rocks and largest in the sedimentary types. Variations due to orientation were within the precision of measurements (+- 5%). In most cases the thermal conductivities were linear with the reciprocal of the temperature and were within 14% of published data obtained by other methods. Measurements were made by a cut-bar comparison method in which the sample was sandwiched between two reference or metering bars made of Pyroceram 9606 glass-ceramic. The apparatus consisted of a Dynatech Model TCFCM-N20 comparative thermal conductivity analyzer controlled by a Hewlett Packard Model 3052A data acquisition system. A program was written to increment and cycle the temperature in steps between predetermined initial and maximum values. At each step the thermal conductivity was measured after steady-state conditions were established. The rocks furnished by the Bureau of Mines were quarried in large and fairly homogeneous lots for use by researchers at various laboratories. To investigate any anisotropy, cores were taken from each rock cube perpendicular to each of the cube faces. Samples 2 in. in diameter and approx. 0.75 in. thick were prepared from the cores and were dried in a vacuum oven for at least one month prior to taking measurements

  5. Chemical buffering capacity of clay rock

    International Nuclear Information System (INIS)

    Beaucaire, C.; Pearson, F.J.; Gautschi, A.

    2004-01-01

    The long-term performance of a nuclear waste repository is strongly dependent on the chemical properties of the host rock. The host rock establishes the chemical environment that determines such important performance attributes as radionuclide solubilities from the waste and the transport rates from the repository to the accessible environment. Clay-rich rocks are especially favourable host rocks because they provide a strong buffering capacity to resist chemical changes prompted either internally, by reactions of the waste itself and emplacement materials, or externally, by changes in the hydrologic systems surrounding the host rock. This paper will focus on three aspects of the stability of clay-rich host rocks: their ability to provide pCO 2 and redox buffering, and to resist chemical changes imposed by changes in regional hydrology and hydro-chemistry. (authors)

  6. The rock art of Mwana wa Chentcherere II rock shelter, Malawi : a site-specific study of girls' initiation rock art

    NARCIS (Netherlands)

    Zubieta, L.F.

    2006-01-01

    Mwana wa Chentcherere II, or Chentcherere Rock Shelter II, the name by which it was more generally known when it was excavated in 1972, is one of the largest rock painting sites in Malawi. It has been a national monument since 1972 and has been the subject of extensive archaeological research. This

  7. High-pressure mechanical instability in rocks.

    Science.gov (United States)

    Byerlee, J D; Brace, W F

    1969-05-09

    At a confining pressure of a few kilobars, deformation of many sedimentary rocks, altered mafic rocks, porous volcanic rocks, and sand is ductile, in that instabilities leading to audible elastic shocks are absent. At pressures of 7 to 10 kilobars, however, unstable faulting and stick-slip in certain of these rocks was observed. This high pressure-low temperature instability might be responsible for earthquakes in deeply buried sedimentary or volcanic sequences.

  8. ROCK1 and ROCK2 are Required for Non-Small Cell Lung Cancer Anchorage-Independent Growth and Invasion

    OpenAIRE

    Vigil, Dominico; Kim, Tai Young; Plachco, Ana; Garton, Andrew J.; Castaldo, Linda; Pachter, Jonathan A.; Dong, Hanqing; Chen, Xin; Tokar, Brianna; Campbell, Sharon L.; Der, Channing J.

    2012-01-01

    Evidence is emerging that the closely related ROCK1 and ROCK2 serine/threonine kinases support the invasive and metastatic growth of a spectrum of human cancer types. Therefore, inhibitors of ROCK are under preclinical development. However, a key step in their development involves the identification of genetic biomarkers that will predict ROCK inhibitor anti-tumor activity. One identified mechanism for ROCK activation in cancer involves the loss of function of the DLC1 tumor suppressor gene, ...

  9. Experimental study of the hydrodynamic instabilities occurring in boiling-water reactors; Etude experimentale des instabilites hydrodynamiques survenant dans les reacteurs nucleaires a ebullition

    Energy Technology Data Exchange (ETDEWEB)

    Fabreca, S [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1964-10-01

    The subjects is an experimental out-of pile loop study of the hydrodynamic oscillations occurring in boiling-water reactors. The study was carried out at atmospheric pressure and at pressure of about 8 atmospheres, in channels heated electrically by a constant and uniform specified current. In the test at 8 atmospheres the channel was a round tube of approximately 6 mm interior diameter. At 1 atmosphere a ring-section channel was used, 10 * 20 mm in diameter, with an inner heating tube and an outer tube of pyrex. It was possible to operate with natural convection and also with forced convection with test-channel by-pass. The study consists of 3 parts: 1. Preliminary determination of the laws governing pressure-drop during boiling. 2. Determination of the fronts at which oscillation appears, within a wide range of the parameters involved. 3. A descriptive study of the oscillations and measurement of the periods. The report gives the oscillation fronts with natural and forced convection for various values of the singular pressure drop at the channel inlet and for various riser lengths. The results are presented in non-dimensional form, which is available, in first approximation, for all geometric scales and for all fluids. Besides the following points were observed: - the wall (nature and thickness) can be an important factor ; - oscillation can occur in a horizontal channel. (author) [French] II a ete effectue une etude experimentale, en boucle hors-pile, des oscillations hydrodynamiques survenant dans les reacteurs a ebullition. L'etude a ete effectuee a la pression atmospherique et a une pression voisine de 8 atmospheres dans des canaux chauffes electriquement a puissance imposee constante et uniforme. Dans les essais a 8 atmospheres le canal etait un tube circulaire de diametre interieur 6 mm environ. A 1 atmosphere le canal etait de section annulaire 10 * 20 mm avec un tube interieur chauffant et un tube exterieur en pyrex. Le fonctionnement etait possible en

  10. Use of hydraulic and aerial mock up to study atmospheric pollution; L'utilisation des maquettes aeriennes et hydrauliques pour l'etude de la pollution atmospherique

    Energy Technology Data Exchange (ETDEWEB)

    Facy, L; Perrin De Brichambaut, C; Doury, A; Le Quinio, R

    1962-07-01

    Fundamental studies on turbulent atmospheric diffusion of finely divided particles, cannot remain on a purely theoretical basis. Further experimental studies must be considered. - In full scale, from accidental and induced releases. - On a reduced scale, in aerodynamic wind tunnels or hydraulic water tunnels. A first set of studies on reduced scale models has been worked out according to a contract between French 'Meteorologie Nationale' and French 'Commissariat a l'Energie Atomique' and with the Collaboration of Saint-Cyr 'Institut Aerotechnique'. Essentially two kinds of results have been obtained: - The mathematical model of SUTTON for the turbulent diffusion in the atmosphere, deduced from the SUTTON theory, generally used by us, has been correctly verified, qualitatively and quantitatively whenever experiments were consistent with the theory conditions. - The quantitative assays of photographic and cinematographic visualization have given precise details on the phenomena inaccessible to calculations, due to the influence of obstacles and release conditions. - Generally, it can be asserted, that the atmospheric pollution studies are worked out by mock up experimentations and that, in some cases these experiments never can be replaced by mathematically pure models. (authors) [French] Les etudes fondamentales portant sur la diffusion turbulente dans l'atmosphere de quantites de matieres finement divisees, ne peuvent se maintenir sur un plan exclusivement theorique. C'est pourquoi des etudes experimentales complementaires doivent etre obligatoirement envisagees: - en vraie grandeur, a partir d'emissions accidentelles ou provoquees; - sur modeles reduits, en soufflerie aerodynamique ou en veine hydraulique. En ce qui concerne les modeles reduits, une premiere serie d'etudes a pu etre menee a bien, dans le cadre d'un contrat passe entre la Meteorologie Nationale et le Commissariat a l'Energie Atomique, et avec la collaboration de l'Institut Aerotechnique de Saint

  11. Proposal of rock mass behavior classification based on convergence measurement in shaft sinking through sedimentary soft rocks

    International Nuclear Information System (INIS)

    Tsusaka, Kimikazu

    2010-01-01

    Japan Atomic Energy Agency has been excavating deep shafts through sedimentary soft rocks in Horonobe, Hokkaido. From the viewpoint of the observational construction, site engineers need a practical guide to evaluate the field measurements conducted with shaft sinking. The author analyzed the relationship among initial deformation rate, observed deformation, the ratio of the modulus of elasticity of rock mass to the initial stress, and the magnitude of inelastic behavior of rock based on convergence measurements and investigation of rock mass properties on shaft walls. As a result, the rock mass behavior classification for shaft sinking which consists of three classes was proposed. (author)

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

    Science.gov (United States)

    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

  13. Evaluation of the layering of rock strata and basement rock depth of ...

    African Journals Online (AJOL)

    The layering of rock strata and depth to the basement rocks of a Federal University Teaching Hospital premises in Northern Nigeria was investigated in this study with the aim of providing 2D geo-electrical resistivity images of the subsurface for geotechnical development using a modern and state-of-the-art field instrument, ...

  14. ONKALO rock mechanics model (RMM). Version 2.3

    Energy Technology Data Exchange (ETDEWEB)

    Haekkinen, T.; Merjama, S.; Moenkkoenen, H. [WSP Finland, Helsinki (Finland)

    2014-07-15

    The Rock Mechanics Model of the ONKALO rock volume includes the most important rock mechanics features and parameters at the Olkiluoto site. The main objective of the model is to be a tool to predict rock properties, rock quality and hence provide an estimate for the rock stability of the potential repository at Olkiluoto. The model includes a database of rock mechanics raw data and a block model in which the rock mechanics parameters are estimated through block volumes based on spatial rock mechanics raw data. In this version 2.3, special emphasis was placed on refining the estimation of the block model. The model was divided into rock mechanics domains which were used as constraints during the block model estimation. During the modelling process, a display profile and toolbar were developed for the GEOVIA Surpac software to improve visualisation and access to the rock mechanics data for the Olkiluoto area. (orig.)

  15. Pore Type Classification on Carbonate Reservoir in Offshore Sarawak using Rock Physics Model and Rock Digital Images

    International Nuclear Information System (INIS)

    Lubis, L A; Harith, Z Z T

    2014-01-01

    It has been recognized that carbonate reservoirs are one of the biggest sources of hydrocarbon. Clearly, the evaluation of these reservoirs is important and critical. For rigorous reservoir characterization and performance prediction from geophysical measurements, the exact interpretation of geophysical response of different carbonate pore types is crucial. Yet, the characterization of carbonate reservoir rocks is difficult due to their complex pore systems. The significant diagenesis process and complex depositional environment makes pore systems in carbonates far more complicated than in clastics. Therefore, it is difficult to establish rock physics model for carbonate rock type. In this paper, we evaluate the possible rock physics model of 20 core plugs of a Miocene carbonate platform in Central Luconia, Sarawak. The published laboratory data of this area were used as an input to create the carbonate rock physics models. The elastic properties were analyzed to examine the validity of an existing analytical carbonate rock physics model. We integrate the Xu-Payne Differential Effective Medium (DEM) Model and the elastic modulus which was simulated from a digital carbonate rock image using Finite Element Modeling. The results of this integration matched well for the separation of carbonate pore types and sonic P-wave velocity obtained from laboratory measurement. Thus, the results of this study show that the integration of rock digital image and theoretical rock physics might improve the elastic properties prediction and useful for more advance geophysical techniques (e.g. Seismic Inversion) of carbonate reservoir in Sarawak

  16. Rock strength under explosive loading

    International Nuclear Information System (INIS)

    Rimer, N.; Proffer, W.

    1993-01-01

    This presentation emphasizes the importance of a detailed description of the nonlinear deviatoric (strength) response of the surrounding rock in the numerical simulation of underground nuclear explosion phenomenology to the late times needed for test ban monitoring applications. We will show how numerical simulations which match ground motion measurements in volcanic tuffs and in granite use the strength values obtained from laboratory measurements on small core samples of these rocks but also require much lower strength values after the ground motion has interacted with the rock. The underlying physical mechanisms for the implied strength reduction are not yet well understood, and in fact may depend on the particular rock type. However, constitutive models for shock damage and/or effective stress have been used successfully at S-Cubed in both the Geophysics Program (primarily for DARPA) and the Containment Support Program (for DNA) to simulate late time ground motions measured at NTS in many different rock types

  17. ROCK inhibitors in ocular disease

    Directory of Open Access Journals (Sweden)

    Eva Halasz

    2016-12-01

    Full Text Available Rho kinases (ROCKs have a crucial role in actin-cytoskeletal reorganization and thus are involved in broad aspects of cell motility, from smooth muscle contraction to neurite outgrowth. The first marketed ROCK inhibitor, called fasudil, has been used safely for treatment of cerebral vasospasm since 1995 in Japan. During the succeeding decades ROCK inhibitors have been applied in many pathological conditions from central nervous system disorders to cardiovascular disease as potential therapeutic agents or experimental tools to help understand the underlying (pathomechanisms. In 2014, a fasudil derivate named ripasudil was accepted for clinical use in glaucoma and ocular hypertension. Since ROCK kinases are widely expressed in ocular tissues, they have been implicated in the pathology of many ocular conditions such as corneal dysfunction, glaucoma, cataract, diabetic retinopathy, age-related macular degeneration, and retinal detachment. This paper aims to provide an overview of the most recent status/application of ROCK inhibitors in the field of eye disease.

  18. Creep in the sparsely fractured rock between a disposal vault and a zone of highly fractured rock

    International Nuclear Information System (INIS)

    Wilkins, B.J.S.; Rigby, G.L.

    1993-08-01

    AECL Research is responsible for investigating the feasibility and safety of the disposal of Canada's nuclear fuel waste deep in the plutonic rock of the Canadian Shield. The excavation of the disposal vault, the installation of sealing systems and the heat generated by the fuel waste will all perturb the in situ stress state of the rock mass. This computer codes HOTROK, MCROC and MCDIRC are used to analyze the influence of these stress perturbations on the mechanical behaviour of the rock mass. Time-dependent microcracking of the rock mass will lead to creep around openings in the vault. The analysis specifically estimates the resulting creep strain in the sparsely fractured rock between the edge of the disposal vault and a postulated zone of highly fractured rock. The estimates are extremely conservative. The conclusion reached is that the rock mass more than 3 m beyond the edge of the vault will experience < 0.001 creep strain 100 000 years after the fuel waste is emplaced. (author). 10 refs., 4 tabs., 4 figs

  19. Study and installation of concrete shielding in the civil engineering of nuclear construction (1960); Etude et mise en place des betons de protection dans le genie civil des ouvrages nucleaires (1960)

    Energy Technology Data Exchange (ETDEWEB)

    Dubois, F. [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    The object of this report is to give technical information about high density concretes which have become very important for radiation biological shielding. The most generally used heavy aggregates (barytes, ilmenite, ferrophosphorus, limonite, magnetite and iron punching) to make these concretes are investigated from the point of view prospecting and physical and chemical characteristics. At first, a general survey of shielding concretes is made involving the study of components, mixing and placing methods, then, a detailed investigation of some high density concretes: barytes concrete, with incorporation of iron punching or iron shot, ferrophosphorus concrete, ilmenite concrete and magnetite concrete, more particularly with regard to grading and mix proportions and testing process. To put this survey in concrete form, two practical designs are described such as they have been carried out at the Saclay Nuclear Station. Specifications are given for diverse concretes and for making the proton-synchrotron 'Saturne' shielding blocks. (author) [French] Ce rapport a pour objet de donner des precisions techniques au sujet des betons a haute densite qui ont pris une grande importance pour la protection biologique contre les rayonnements. Les agregats lourds les plus couramment utilises (barytine, ilmenite, ferrophosphore, limonite, magnetite et riblons) pour la fabrication de ces betons, sont examines du point de vue prospection et caracteristiques physiques et chimiques. On procede d'abord a une etude generale des betons de protection comprenant l'etude des constituants, de la confection et de la mise en place, ensuite, a un examen detaille de quelques betons a haute densite: betons a base de barytine, avec incorporation de riblons ou de grenaille de fonte, betons au ferrophosphore, a base d'ilmenite ou de magnetite, notamment en ce qui concerne la granulometrie, la composition, le dosage et les processus d'essais. Pour concretiser ces

  20. Contribution to the study on the flow rate adjustment for gas cooled power reactors (1964); Contributiom a l'etude de reglage du debit pour les reacteurs industriels refroidis par gaz (1964)

    Energy Technology Data Exchange (ETDEWEB)

    Milliot, B [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1961-06-15

    1. This original study firstly defines the problem of the adjustment of the coolant flow rate in a reactor channel as a function of the corresponding heat transfer equations and of the local and temporal neutron flux. The necessity of such an adjustment is pointed out and the modifying parameters are studied. An adjustment study using the envelope of the possible flux curves is developed. A short study on the technology and the economical advantage of this adjustment is presented. Some measurements, made on G-1 and G-2, show the precision one can obtain from adjustment apparatus itself as well as from the complete reactor adjustment system. 2. Evolution of nuclear properties of fuel in an heterogeneous thermal reactor. In the first port of this paper, the phenomena of fuel evolution have been mainly pointed out. Now a bibliographical study more qualitatively than quantitatively has been done. This survey specifies the present theories and relates to a real effective cross section and also yields to the bases of such a nuclear calculation. (author) [French] 1. Cette etude originale definit d'abord le probleme du reglage du debit de refrigerant dans un canal de reacteur en fonction de la formulation du calcul des performances thermodynamiques de ce canal et des variations du flux neutronique dans l'espace et le temps. La necessite du reglage est ensuite mise en evidence et les parametres le modifiant sont etudies. Une methode de reglage, basee sur l'emploi d 'une courbe enveloppe des courbes de flux possibles, est donnee. Une breve etude de la technologie et des incidences economiques du reglage est presentee. Des mesures effectuees sur les reacteurs G-1 et G-2 montrent la precision que l'on peut attendre des dispositifs de reglage comme du reglage d'ensemble du reacteur lui-meme. 2. Evolution des proprietes nucleaires du combustible dans un reacteur heterogene a neutrons thermiques. Les phenomenes d'evolution du combustible tiennent une place importante dans l'etude

  1. Rock cavern storage of spent fuel

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Won Jin; Kim, Kyung Soo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Kwon, Sang Ki [Inha University, Incheon (Korea, Republic of)

    2015-12-15

    The rock cavern storage for spent fuel has been assessed to apply in Korea with reviewing the state of the art of the technologies for surface storage and rock cavern storage of spent fuel. The technical feasibility and economic aspects of the rock cavern storage of spent fuel were also analyzed. A considerable area of flat land isolated from the exterior are needed to meet the requirement for the site of the surface storage facilities. It may, however, not be easy to secure such areas in the mountainous region of Korea. Instead, the spent fuel storage facilities constructed in the rock cavern moderate their demands for the suitable site. As a result, the rock cavern storage is a promising alternative for the storage of spent fuel in the aspect of natural and social environments. The rock cavern storage of spent fuel has several advantages compared with the surface storage, and there is no significant difference on the viewpoint of economy between the two alternatives. In addition, no great technical difficulties are present to apply the rock cavern storage technologies to the storage of domestic spent fuel.

  2. Magnetic study of solid uranium-fluorine complexes; Contribution a l'etude magnetique de composes fluores solides de l'uranium

    Energy Technology Data Exchange (ETDEWEB)

    Dianoux, A J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1969-06-01

    A study of the magnetic susceptibility of uranium V fluorine complexes and of the magnetic resonance of fluorine atoms in uranium VI fluorine complexes has made it possible to put forward a structural model for these compounds for which it is impossible, because of the lack of suitable single crystals for X-ray diffraction work, to deduce the exact position of the fluorine atoms. It is shown that it is difficult to interpret the paramagnetism of uranium fluorides, because the uranium ions are in low-symmetry sites. A theoretical study of the magnetism of the U{sup V} ion in complex fluorides of the type M{sub 3}UF{sub 8} (M = NH{sub 4}, Na, Rb, Cs) leads to an interpretation based on a trigonal deformation of the eight fluorine atom structure surrounding the uranium atom. By applying a Hamiltonian spin formalism and making a systematic use of group theory, it is possible to present the susceptibility calculations very concisely. Study of the resonance and of the relaxation of the fluorine atoms in powdered uranium VI complex fluorides suggests a structural model in the case of NaUF{sub 7}. It is shown that the shape of the magnetic resonance absorption lines is strongly affected by the presence of large anisotropic chemical shifts. In the model proposed here, six fluorine atoms are linked to the uranium, atom by strongly covalent bonds in a deformed UF{sub 6} octahedral structure; the seventh fluorine atom remains ionic. The occurrence of a rotational movement of the octahedron is confirmed by a study of the longitudinal relaxation of the fluorine atoms, the activation energy being 0.46 eV. (author) [French] L'etude de la susceptibilite magnetique de complexes fluores d'uranium V et la resonance magnetique des fluors dans des complexes fluores d'uranium VI permettent de proposer un modele structural pour ces composes, ou la diffraction des rayons X, en l'absence de monocristaux convenables, est incapable de preciser la position des atomes de fluor. Nous montrons

  3. An economic study of the site of Marcoule; Etude economique du site de Marcoule

    Energy Technology Data Exchange (ETDEWEB)

    Duprat, H [Commissariat a l' Energie Atomique, Marcoule (France). Centre d' Etudes Nucleaires

    1964-07-01

    The study of this site of the Marcoule Center shows that its regional economical influence is limited to the buying power distributed among its personnel. This entails distortions between first this supplementary buying power and the overall markets within the possible Marcoule influence zone, and secondly the concentration on Bagnols-sur-Ceze and this town's normal extension possibilities. (author) [French] L'etude du site de Marcoule demontre que son influence economique se limite, pour la region, au pouvoir d'achat distribue a son personnel. Ceci entraine une disproportion d'une part entre ce pouvoir d'achat supplementaire et l'ensemble des marches contenus dans l'aire d'influence possible de Marcoule, d'autre part entre la concentration realisee a Bagnole-sur-Ceze et la capacite d'extension normale de cette agglomeration. (auteur)

  4. Discussion on the origin of sedimentary rock resistivity

    International Nuclear Information System (INIS)

    Dong Gangjian

    2012-01-01

    Conduction current way of sedimentary rock sedimentary rock is caused by the internal structure of sedimentary rock sedimentary rock pore resistance depends on the salinity of pore water and clay content and distribution. Resistivity of sedimentary rock sedimentary rock major factor in mineral composition, water resistance, oil resistance. and sedimentary structures. In practice, we should give full attention to the difference between lithology and physical properties. (author)

  5. Heterogeneous Rock Simulation Using DIP-Micromechanics-Statistical Methods

    Directory of Open Access Journals (Sweden)

    H. Molladavoodi

    2018-01-01

    Full Text Available Rock as a natural material is heterogeneous. Rock material consists of minerals, crystals, cement, grains, and microcracks. Each component of rock has a different mechanical behavior under applied loading condition. Therefore, rock component distribution has an important effect on rock mechanical behavior, especially in the postpeak region. In this paper, the rock sample was studied by digital image processing (DIP, micromechanics, and statistical methods. Using image processing, volume fractions of the rock minerals composing the rock sample were evaluated precisely. The mechanical properties of the rock matrix were determined based on upscaling micromechanics. In order to consider the rock heterogeneities effect on mechanical behavior, the heterogeneity index was calculated in a framework of statistical method. A Weibull distribution function was fitted to the Young modulus distribution of minerals. Finally, statistical and Mohr–Coulomb strain-softening models were used simultaneously as a constitutive model in DEM code. The acoustic emission, strain energy release, and the effect of rock heterogeneities on the postpeak behavior process were investigated. The numerical results are in good agreement with experimental data.

  6. Rock Art: Connecting to the Past.

    Science.gov (United States)

    Knipe, Marianne

    2001-01-01

    Presents an activity for fourth-grade students in which they learn about ancient art and create their own authentic-looking rock sculptures with pictograms, or painted images. Explains how the students create their own rocks and then paint a pictograph on the rocks with brown paint. (CMK)

  7. Processing radioactive effluents with ion-exchanging resins: study of result extrapolation; Traitement des effluents radioactifs par resines echangeuses d'ions: etude de l'extrapolation des resultats

    Energy Technology Data Exchange (ETDEWEB)

    Wormser, G.

    1960-05-03

    As a previous study showed the ion-exchanging resins could be used in Saclay for the treatment of radioactive effluents, the author reports a study which aimed at investigating to which extent thus obtained results could be extrapolated to the case of higher industrial columns. The author reports experiments which aimed at determining extrapolation modes which could be used for columns of organic resin used for radioactive effluent decontamination. He notably studied whether the Hiester and Vermeulen extrapolation law could be applied. Experiments are performed at constant percolation flow rate, at varying flow rate, and at constant flow rate [French] Plusieurs etudes ont ete faites dans le but d'examiner les possibilites d'emploi des resines echangeuses d'ions pour le traitement des effluents radioactifs. Dans un rapport preliminaire, nous avons montre dans quelles limites un tel procede pouvait etre utilise au Centre d'Etudes Nucleaires de Saclay. Les essais ont ete effectues sur des petites colonnes de resine au laboratoire; il est apparu ensuite necessaire de prevoir dans quelle mesure les resultats ainsi obtenus peuvent etre extrapoles a des colonnes industrielles, de plus grande hauteur. Les experiences dont les resultats sont exposes dans ce rapport, ont pour but de determiner les modes d'extrapolation qui pourraient etre employes pour des colonnes de resine organique utilisees pour la decontamination d'effluents radioactifs. Nous avons en particulier recherche si la loi d'extrapolation de Hiester et Vermeulen qui donne de bons resultats dans le cas de fixation d'ions radioactifs en presence d'un ion macrocomposant sur des terres, pouvait etre appliquee. Les experiences, en nombre limite, ont montre que la loi d'extrapolation de Hiester et Vermeulen pouvait s'appliquer dans le cas de l'effluent considere quand les debits de percolation sont tres faibles; quand ils sont plus forts, les volumes de liquide percoles, a fixation egale, sont proportionnels aux

  8. White Rock

    Science.gov (United States)

    2002-01-01

    (Released 19 April 2002) The Science 'White Rock' is the unofficial name for this unusual landform which was first observed during the Mariner 9 mission in the early 1970's. As later analysis of additional data sets would show, White Rock is neither white nor dense rock. Its apparent brightness arises from the fact that the material surrounding it is so dark. Images from the Mars Global Surveyor MOC camera revealed dark sand dunes surrounding White Rock and on the floor of the troughs within it. Some of these dunes are just apparent in the THEMIS image. Although there was speculation that the material composing White Rock could be salts from an ancient dry lakebed, spectral data from the MGS TES instrument did not support this claim. Instead, the White Rock deposit may be the erosional remnant of a previously more continuous occurrence of air fall sediments, either volcanic ash or windblown dust. The THEMIS image offers new evidence for the idea that the original deposit covered a larger area. Approximately 10 kilometers to the southeast of the main deposit are some tiny knobs of similarly bright material preserved on the floor of a small crater. Given that the eolian erosion of the main White Rock deposit has produced isolated knobs at its edges, it is reasonable to suspect that the more distant outliers are the remnants of a once continuous deposit that stretched at least to this location. The fact that so little remains of the larger deposit suggests that the material is very easily eroded and simply blows away. The Story Fingers of hard, white rock seem to jut out like icy daggers across a moody Martian surface, but appearances can be deceiving. These bright, jagged features are neither white, nor icy, nor even hard and rocky! So what are they, and why are they so different from the surrounding terrain? Scientists know that you can't always trust what your eyes see alone. You have to use other kinds of science instruments to measure things that our eyes can

  9. Abraded Target on Rock 'Champagne' in Gusev Crater

    Science.gov (United States)

    2005-01-01

    NASA's Mars Exploration Rover Spirit took this microscopic image of a target called 'Bubbles' on a rock called 'Champagne' after using its rock abrasion tool to grind a hole through the rock's outer surface. The circular area where the rock's interior is exposed is about 5 centimeters (2 inches) across. This rock is different from rocks out on the plains of Gusev Crater but is similar to other rocks in this area of the 'Columbia Hills' in that it rich in phosphorus. Plagioclase, a mineral commonly found in igneous rocks, is also present in these rocks, according to analysis with Spirit's miniature thermal emission spectrometer. By using the rover's alpha particle X-ray spectrometer to collect data for multiple martian days, or sols, scientists are also beginning to get measurements of trace elements in the rocks. Spirit took the images that are combined into this mosaic on sol 358 (Jan. 3, 2005).

  10. Diffusion in the matrix of granitic rock

    International Nuclear Information System (INIS)

    Birgersson, L.; Neretnieks, I.

    1982-07-01

    A migration experiment in the rock matrix is presented. The experiment has been carried out in undisturbed rock, that is rock under its natural stress environment. Since the experiment was performed at the 360 m-level (in the Stripa mine), the rock had nearly the same conditions as the rock surrounding a nuclear waste storage. The results show that all three tracers (Uranine, Cr-EDTA and I - ) have passed the disturbed zone from the injection hole and migrated into undisturbed rock. At the distance of 11 cm from the injection hole 5-10 percent of the injection concentration was found. The results also indicate that the tracer have passed through fissure filling material. These results indicate that it is possible for tracers (and therefore radionuclides) to migrate from a fissure, through fissure filling material, and into the undisturbed rock matrix. (Authors)

  11. Carbonate rock depositional models: A microfacies approach

    Energy Technology Data Exchange (ETDEWEB)

    Carozzi, A.V.

    1988-01-01

    Carbonate rocks contain more than 50% by weight carbonate minerals such as calcite, dolomite, and siderite. Understanding how these rocks form can lead to more efficient methods of petroleum exploration. Micofacies analysis techniques can be used as a method of predicting models of sedimentation for carbonate rocks. Micofacies in carbonate rocks can be seen clearly only in thin sections under a microscope. This section analysis of carbonate rocks is a tool that can be used to understand depositional environments, diagenetic evolution of carbonate rocks, and the formation of porosity and permeability in carbonate rocks. The use of micofacies analysis techniques is applied to understanding the origin and formation of carbonate ramps, carbonate platforms, and carbonate slopes and basins. This book will be of interest to students and professionals concerned with the disciplines of sedimentary petrology, sedimentology, petroleum geology, and palentology.

  12. Cell for studying electron-adsorbed gas interactions; Cellule d'etudes des interactions electron-gaz adsorbe

    Energy Technology Data Exchange (ETDEWEB)

    Golowacz, H; Degras, D A [Commissariat a l' Energie Atomique, 91 - Saclay (France). Centre d' Etudes Nucleaires, Deptartement de Physique des Plasmas et de la Fusion Controlee, Service de Physique Appliquee, Service de Physique des Interractions Electroniques, Section d' Etude des Interactions Gaz-Solides

    1967-07-01

    The geometry and the technology of a cell used for investigations on electron-adsorbed gas interactions are described. The resonance frequencies of the surface ions which are created by the electron impact on the adsorbed gas are predicted by simplified calculations. The experimental data relative to carbon monoxide and neon are in good agreement with these predictions. (authors) [French] Les caracteristiques geometriques et technologiques generales d'une cellule d'etude des interactions entre un faisceau d'electrons et un gaz adsorbe sont donnees. Un calcul simplifie permet de prevoir les frequences de resonance des ions de surface crees par l'impact des electrons sur le gaz adsorbe. Les donnees experimentales sur l'oxyde de carbone et le neon confirment les previsions du calcul. (auteurs)

  13. Rock-degrading endophytic bacteria in cacti

    Science.gov (United States)

    M. Esther Puente; Ching Y. Li; Yoav Bashan

    2009-01-01

    A plant-bacterium association of the cardon cactus (Pachycereus pringlei) and endophytic bacteria promotes establishment of seedlings and growth on igneous rocks without soil. These bacteria weather several rock types and minerals, unbind significant amounts of useful minerals for plants from the rocks, fix in vitro N2. produce...

  14. Rock Music's Place in the Library.

    Science.gov (United States)

    Politis, John

    1983-01-01

    Discussion of the importance of rock music as an expression of aural culture includes its history, rock music today, and the development of a rock music collection in the library (placement of collection and books which aid in developing a collection of permanent value). Three references are included. (EJS)

  15. Rock avalanche and rock glacier: A compound landform study from Hornsund, Svalbard

    Czech Academy of Sciences Publication Activity Database

    Hartvich, Filip; Blahůt, Jan; Stemberk, Josef

    2017-01-01

    Roč. 276, JAN 1 (2017), s. 244-256 ISSN 0169-555X R&D Projects: GA MŠk(CZ) LM2015079; GA MŠk(CZ) LG15007 Institutional support: RVO:67985891 Keywords : ERT * TLS (LiDAR) * lichenometry * morphometry * rock avalanche * rock glacier * Schmidt hammer * Svalbard * Hornsund Subject RIV: DB - Geology ; Mineralogy OBOR OECD: Geology Impact factor: 2.958, year: 2016

  16. Efficacy and Safety of Atrial Fibrillation Ablation Using Remote Magnetic Navigation

    DEFF Research Database (Denmark)

    Jin, Q I; Pehrson, Steen; Jacobsen, Peter Karl

    2016-01-01

    .0 minutes, PerAF, P = 0.17). The overall complication rate was 0.6%. One PAF patient experienced cardiac tamponade. AF repeat ablations by RMN significantly reduced the procedural and ablation times when compared with their first ablation times. CONCLUSIONS: AF ablation guided by RMN is safe as evidenced...

  17. Tunnel Design by Rock Mass Classifications

    Science.gov (United States)

    1990-01-01

    Engineering," revised second edition, Institution of Mining and Metallurgy, London, 1977, pp 113-115 and 150-192. 42. Selmer - Olsen , R., and Broch, E...to wall when a)/03 > 10, re- stability) ................ 10-5 0.66-0.33 0.5-2.0 duce oc and ot to L. Mild rock burst (massive 0.6 cc and 0.6 on rock ...5-2.5 0.33-0.16 5-10 where: 0 c = uncon-fined compression M. Heavy rock burst (massive strength, at = rock

  18. Rock breaking methods to replace blasting

    Science.gov (United States)

    Zhou, Huisheng; Xie, Xinghua; Feng, Yuqing

    2018-03-01

    The method of breaking rock by blasting has a high efficiency and the cost is relatively low, but the associated vibration, flyrock, production of toxic gases since the 1970’s, the Western developed countries began to study the safety of breaking rock. This paper introduces different methods and their progress to safely break rock. Ideally, safe rock breaking would have little vibration, no fly stone, and no toxic gases, which can be widely used in municipal engineering, road excavation, high-risk mining, quarrying and complex environment.

  19. Sorption of radionuclides on hard rocks

    International Nuclear Information System (INIS)

    Berry, J.A.; Bourke, P.J.; Green, A.; Littleboy, A.K.

    1987-09-01

    Methods for measuring sorption on hard rocks, particularly of strontium, caesium, neptunium and americium on Darley Dale sandstone and Welsh slate have been investigated. The methods tried included batch tests with crushed rock and tests of simultaneous diffusion and convection with sorption on intact rock. High pressures (800m H 2 O) were used in the convective tests to pump water quickly through the rock samples and to measure high sorptivities in times shorter than those needed in the diffusive methods with intact samples. (author)

  20. Finding the right rocks on Mars

    Science.gov (United States)

    Hargraves, R. B.; Knudsen, J. M.; Madsen, M. B.; Bertelsen, P.

    Locating a rock on the surface of Mars that bears unambiguous evidence of the existence—prior or present—of life on that planet is, understandably, the “Holy Grail” of NASAs sample return missions. Remote recognition of such a rock on Mars will not be easy. We do know, however, that present in the Martian crust—especially in the “Southern highlands”—is rock carrying strong natural remanent magnetization (NRM). Characterization of such magnetized rock has profound implications for adding to our knowledge about the origin and early evolution of the Martian interior, lithosphere, atmosphere, and possibly even Martian life forms [Ward and Brownlee, 2000]. Moreover, it should be possible to recognize such rocks by use of a simple magnetic compass mounted on a Rover.

  1. Phosphine from rocks: mechanically driven phosphate reduction?

    Science.gov (United States)

    Glindemann, Dietmar; Edwards, Marc; Morgenstern, Peter

    2005-11-01

    Natural rock and mineral samples released trace amounts of phosphine during dissolution in mineral acid. An order of magnitude more phosphine (average 1982 ng PH3 kg rock and maximum 6673 ng PH3/kg rock) is released from pulverized rock samples (basalt, gneiss, granite, clay, quartzitic pebbles, or marble). Phosphine was correlated to hardness and mechanical pulverization energy of the rocks. The yield of PH3 ranged from 0 to 0.01% of the total P content of the dissolved rock. Strong circumstantial evidence was gathered for reduction of phosphate in the rock via mechanochemical or "tribochemical" weathering at quartz and calcite/marble inclusions. Artificial reproduction of this mechanism by rubbing quartz rods coated with apatite-phosphate to the point of visible triboluminescence, led to detection of more than 70 000 ng/kg PH3 in the apatite. This reaction pathway may be considered a mechano-chemical analogue of phosphate reduction from lightning or electrical discharges and may contribute to phosphine production via tectonic forces and processing of rocks.

  2. 27 CFR 9.203 - Saddle Rock-Malibu.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Saddle Rock-Malibu. 9.203... Saddle Rock-Malibu. (a) Name. The name of the viticultural area described in this section is “Saddle Rock-Malibu”. For purposes of part 4 of this chapter, “Saddle Rock-Malibu” is a term of viticultural...

  3. Professional users handbook for rock bolting

    Energy Technology Data Exchange (ETDEWEB)

    Stillborg, B.

    1986-01-01

    The paper is a practical handbook which reviews the basic principles of rock bolting and sets out the design considerations used for most types of rockbolts in current use. It discusses the characteristics of these bolts and gives information on installation procedures and the observations and measurement of rockbolt performance. Rockbolting is considered under the following chapter headings: review of typical rockbolt systems; rockbolt installation; testing of rockbolts; design considerations; design of rock reinforcement; monitoring; cost of rock bolting; and Atlas Lopco auxillary equipment for rock bolting. 45 refs.

  4. Baby fission chambers; Etude de chambres a fission miniatures

    Energy Technology Data Exchange (ETDEWEB)

    Guery, U.; Tachon, J. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1957-07-01

    The present report is intended, on the one band, as a study of the main types of fission chambers produced to date, and on the other, to deal more generally with this type of detector. Originally, it was with a view to the charting of neutron scatter in 'Proserpine' that the authors undertook the study of these chambers. During the course of the task, it was considered worth tbe trouble of developing its scope to include a more general application: neutron scatter measurement of various energy neutrons within a reduced volume with slight local disturbance. (author) [French] Le present rapport se propose, d'une part, d'exposer les principales realisations de chambres a fission, d'autre part de faire une mise au point a caractere plus general sur ces detecteurs. Au depart, c'est surtout en vue des mesures de densite neutronique dans 'Proserpine' que les auteurs ont etudie ces chambres; au cours de la mise au point, il a paru interessant de developper leur etude pour des applications plus generales: mesures de densites de neutrons de differentes energies dans un element de volume tres reduit et avec faible perturbation locale. (auteur)

  5. A Review on the British Rock Music

    OpenAIRE

    Hutapea, Alfian Hadi Pranata

    2011-01-01

    Music has an important role in people’s life. In people’s daily, music is often hearing of course and in people’s customs and traditions music is also be used. Music has many genres, one of them is rock music. Many people like rock music especially youngman because rock music has given a message in a song through enthusiasm expression. Rock music has many subgenres and each of subgenres have a distinctive feature. The developing of rock music is very wide in the world, especially in Great Bri...

  6. The rock mechanical stability of the VLJ repository

    International Nuclear Information System (INIS)

    Kuula, H.; Johansson, E.

    1991-03-01

    The aim of the study was to determine the rock mechanical stability around the VLJ repository based on the rock mechanical monitoring and rock mechanical modeling. Rock mechanical calculations were made in order to calculate the rock mass displacements and to analyze the stability around the VLJ repository The calculations were performed with three diiferent methods: continuum finite difference code FLAC, distinct element code UDEC and three dimensional distinct element code 3DEC. The first analyses were based on preliminary site investigations. The final modeling was based on investigations and rock mechanical monitoring done during the excavation. Some sensitive analyses were also performed. The modelled rock mass behaviour and the measured behaviour are generally close to each other. Both results show that the VLJ repository is rock mechanically stable. The modelled displacements and stresses were small enough to cause no instability around the rock caverns. The measured values do not indicate any discontinuous deformations like block movements or joint slip. The measured displacements in the extensometers during excavation indicates that the rock mass is even stiffer than anticipated

  7. Radionuclide migration in crystalline rock fractures

    International Nuclear Information System (INIS)

    Hoelttae, P.

    2002-01-01

    Crystalline rock has been considered as a host medium for the repository of high radioactive spent nuclear fuel in Finland. The geosphere will act as an ultimate barrier retarding the migration of radionuclides to the biosphere if they are released through the technical barriers. Radionuclide transport is assumed to take place along watercarrying fractures, and retardation will occur both in the fracture and within the rock matrix. To be able to predict the transport and retardation of radionuclides in rock fractures and rock matrices, it is essential to understand the different phenomena involved. Matrix diffusion has been indicated to be an important mechanism, which will retard the transport of radionuclides in rock fractures. Both dispersion and matrix diffusion are processes, which can have similar influences on solute breakthrough curves in fractured crystalline rock. In this work, the migration of radionuclides in crystalline rock fractures was studied by means of laboratory scale column methods. The purpose of the research was to gain a better understanding of various phenomena - particularly matrix diffusion - affecting the transport and retardation behaviour of radionuclides in fracture flow. Interaction between radionuclides and the rock matrix was measured in order to test the compatibility of experimental retardation parameters and transport models used in assessing the safety of underground repositories for spent nuclear fuel. Rock samples of mica gneiss and of unaltered, moderately altered and strongly altered tonalite represented different rock features and porosities offering the possibility to determine experimental boundary limit values for parameters describing both the transport and retardation of radionuclides and rock matrix properties. The dominant matrix diffusion behaviour was demonstrated in porous ceramic column and gas diffusion experiments. Demonstration of the effects of matrix diffusion in crystalline rock fracture succeeded for the

  8. The three-dimension model for the rock-breaking mechanism of disc cutter and analysis of rock-breaking forces

    Science.gov (United States)

    Zhang, Zhao-Huang; Sun, Fei

    2012-06-01

    To study the rock deformation with three-dimensional model under rolling forces of disc cutter, by carrying out the circular-grooving test with disc cutter rolling around on the rock, the rock mechanical behavior under rolling disc cutter is studied, the mechanical model of disc cutter rolling around the groove is established, and the theory of single-point and double-angle variables is proposed. Based on this theory, the physics equations and geometric equations of rock mechanical behavior under disc cutters of tunnel boring machine (TBM) are studied, and then the balance equations of interactive forces between disc cutter and rock are established. Accordingly, formulas about normal force, rolling force and side force of a disc cutter are derived, and their validity is studied by tests. Therefore, a new method and theory is proposed to study rock-breaking mechanism of disc cutters.

  9. Heat production in granitic rocks

    DEFF Research Database (Denmark)

    Artemieva, Irina; Thybo, Hans; Jakobsen, Kiki

    2017-01-01

    Granitic rocks play special role in the dynamics and evolution of the Earth and its thermal regime. First, their compositional variability, reflected in the distribution of concentrations of radiogenic elements, provides constraints on global differentiation processes and large scale planetary...... evolution, where emplacement of granites is considered a particularly important process for the formation of continental crust. Second, heat production by radioactive decay is among the main heat sources in the Earth. Therefore knowledge of heat production in granitic rocks is pivotal for thermal modelling...... of the continental lithosphere, given that most radiogenic elements are concentrated in granitic rocks of the upper continental crust whereas heat production in rocks of the lower crust and lithospheric mantle is negligible. We present and analyze a new global database GRANITE2017 (with about 500 entries...

  10. Current results of an arachnological survey of some sandstone rock sites in Bohemia (so-called "rock cities"

    Directory of Open Access Journals (Sweden)

    Růžička, Vlastimil

    1992-07-01

    Full Text Available The spider fauna of the Adrspach-Teplice rockswas investigated. Some records on spider fauna of other nine sandstone rock areas are included. The phenomenon of "rock cities" manifests itself in three aspects: (1 In the bottom parts are microclimatically cold spaces, frequently hosting northern ot mountain species of invertebrates, which here have an azonal occurence. (2 the sun exposed tops of rocks can host thermophilous species. (3 Some species are limited to the surface of rocks and boulders. These are referred to as lithophilous or lithobiont species.

  11. Rock-fall potential in the Yosemite Valley, California

    Science.gov (United States)

    Wieczorek, G.F.; Morrissey, M.M.; Iovine, Giulio; Godt, Jonathan

    1999-01-01

    We used two methods of estimating rock-fall potential in the Yosemite Valley, California based on (1) physical evidence of previous rock-fall travel, in which the potential extends to the base of the talus, and (2) theoretical potential energy considerations, in which the potential can extend beyond the base of the talus, herein referred to as the rock-fall shadow. Rock falls in the valley commonly range in size from individual boulders of less than 1 m3 to moderate-sized falls with volumes of about 100,000 m3. Larger rock falls exceeding 100,000 m3, referred to as rock avalanches, are considered to be much less likely to occur based on the relatively few prehistoric rock-fall avalanche deposits in the Yosemite Valley. Because the valley has steep walls and is relatively narrow, there are no areas that are absolutely safe from large rock avalanches. The map shows areas of rock-fall potential, but does not predict when or how frequently a rock fall will occur. Consequently, neither the hazard in terms of probability of a rock fall at any specific location, nor the risk to people or facilities to such events can be assessed from this map.

  12. Remarks on some rock neutron parameters

    International Nuclear Information System (INIS)

    Czubek, J.A.

    1984-01-01

    A method to calculate the thermal neutron parameters of rocks is given in the paper. It is based on a proper energy averaging of cross-sections for all rock matrix and rock saturating liquid constituents. The diffusion lengths in different lithologies in function of the variable rock porosity have been calculated. An influence of the thermal neutron spectrum on the shape of the porosity calibration curves for the dual spacing neutron method is shown. Magmatic rocks as a possible source of geothermal energy are now becoming a target of neutron loggings for the porosity determination. Here the knowledge of the slowing-down lengths is of great importance in the problem of the estimation of the calibration curves. A semi-analytical approach to get this parameter is given in the paper. It was found, as far as concerns the slowing-down of fast neutrons, that all magmatic rocks behave as sandstone with, however, different content of bound water in the rock matrix and different rock matrix density. Some neutron methods are based on the detection of epithermal neutrons. For theoretical considerations it is important to know the physical meaning of the registered signal. From the discussion of experimental data reported in the literature it seems that it is the slowing-down density that is the physical quantity being measured. This conclusion has a very important practical implication - the porosity calibration curves depend upon the slowing-down length alone and are independent of the slowing-down cross-section for epithermal neutrons

  13. Rock Moved by Mars Lander Arm

    Science.gov (United States)

    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.

  14. Permanganate diffusion and reaction in sedimentary rocks.

    Science.gov (United States)

    Huang, Qiuyuan; Dong, Hailiang; Towne, Rachael M; Fischer, Timothy B; Schaefer, Charles E

    2014-04-01

    In situ chemical oxidation using permanganate has frequently been used to treat chlorinated solvents in fractured bedrock aquifers. However, in systems where matrix back-diffusion is an important process, the ability of the oxidant to migrate and treat target contaminants within the rock matrix will likely determine the overall effectiveness of this remedial approach. In this study, a series of diffusion experiments were performed to measure the permanganate diffusion and reaction in four different types of sedimentary rocks (dark gray mudstone, light gray mudstone, red sandstone, and tan sandstone). Results showed that, within the experimental time frame (~2 months), oxidant migration into the rock was limited to distances less than 500 μm. The observed diffusivities for permanganate into the rock matrices ranged from 5.3 × 10(-13) to 1.3 × 10(-11) cm(2)/s. These values were reasonably predicted by accounting for both the rock oxidant demand and the effective diffusivity of the rock. Various Mn minerals formed as surface coatings from reduction of permanganate coupled with oxidation of total organic carbon (TOC), and the nature of the formed Mn minerals was dependent upon the rock type. Post-treatment tracer testing showed that these Mn mineral coatings had a negligible impact on diffusion through the rock. Overall, our results showed that the extent of permanganate diffusion and reaction depended on rock properties, including porosity, mineralogy, and organic carbon. These results have important implications for our understanding of long-term organic contaminant remediation in sedimentary rocks using permanganate. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Fragment Size Distribution of Blasted Rock Mass

    Science.gov (United States)

    Jug, Jasmin; Strelec, Stjepan; Gazdek, Mario; Kavur, Boris

    2017-12-01

    Rock mass is a heterogeneous material, and the heterogeneity of rock causes sizes distribution of fragmented rocks in blasting. Prediction of blasted rock mass fragmentation has a significant role in the overall economics of opencast mines. Blasting as primary fragmentation can significantly decrease the cost of loading, transport, crushing and milling operations. Blast fragmentation chiefly depends on the specific blast design (geometry of blast holes drilling, the quantity and class of explosive, the blasting form, the timing and partition, etc.) and on the properties of the rock mass (including the uniaxial compressive strength, the rock mass elastic Young modulus, the rock discontinuity characteristics and the rock density). Prediction and processing of blasting results researchers can accomplish by a variety of existing software’s and models, one of them is the Kuz-Ram model, which is possibly the most widely used approach to estimating fragmentation from blasting. This paper shows the estimation of fragmentation using the "SB" program, which was created by the authors. Mentioned program includes the Kuz-Ram model. Models of fragmentation are confirmed and calibrated by comparing the estimated fragmentation with actual post-blast fragmentation from image processing techniques. In this study, the Kuz-Ram fragmentation model has been used for an open-pit limestone quarry in Dalmatia, southern Croatia. The resulting calibrated value of the rock factor enables the quality prognosis of fragmentation in further blasting works, with changed drilling geometry and blast design parameters. It also facilitates simulation in the program to optimize blasting works and get the desired fragmentations of the blasted rock mass.

  16. Initial settlements of rock fills on soft clay

    OpenAIRE

    Pedersen, Truls Martens

    2012-01-01

    Rock fills that hit the seabed will remold the underlying material. If this material is a clay with sufficiently low shear strength, it will adopt rheological properties, causing flow through the rock fill, and contributing to the initial settlements of the rock fill in addition to conventional consolidation theory. The settlements of the rocks depend upon the height of the rock fill and how the rocks have been laid out. This is due to the viscosity of the clay, and the fact that clay is thix...

  17. Remarks on some rock neutron parameters

    International Nuclear Information System (INIS)

    Czubek, J.A.

    1983-01-01

    A method to calculate the thermal neutron parameters (absorption cross-section, diffusion coefficient and diffusion length) of rocks is given. It is based on a proper energy averaging of cross-sections for all rock matrix and rock saturating liquid constituents. Special emphasis is given to the presence of hydrogen. The diffusion lengths in different lithologies in the function of the variable rock porosity have been calculated. An influence of the thermal neutron spectrum on the shape of the porosity calibration curves for the dual spacing neutron method is shown. This influence has been estimated on two porosity units, on average. (author)

  18. Experimental study of the hydrodynamic instabilities occurring in boiling-water reactors; Etude experimentale des instabilites hydrodynamiques survenant dans les reacteurs nucleaires a ebullition

    Energy Technology Data Exchange (ETDEWEB)

    Fabreca, S. [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1964-10-01

    The subjects is an experimental out-of pile loop study of the hydrodynamic oscillations occurring in boiling-water reactors. The study was carried out at atmospheric pressure and at pressure of about 8 atmospheres, in channels heated electrically by a constant and uniform specified current. In the test at 8 atmospheres the channel was a round tube of approximately 6 mm interior diameter. At 1 atmosphere a ring-section channel was used, 10 * 20 mm in diameter, with an inner heating tube and an outer tube of pyrex. It was possible to operate with natural convection and also with forced convection with test-channel by-pass. The study consists of 3 parts: 1. Preliminary determination of the laws governing pressure-drop during boiling. 2. Determination of the fronts at which oscillation appears, within a wide range of the parameters involved. 3. A descriptive study of the oscillations and measurement of the periods. The report gives the oscillation fronts with natural and forced convection for various values of the singular pressure drop at the channel inlet and for various riser lengths. The results are presented in non-dimensional form, which is available, in first approximation, for all geometric scales and for all fluids. Besides the following points were observed: - the wall (nature and thickness) can be an important factor ; - oscillation can occur in a horizontal channel. (author) [French] II a ete effectue une etude experimentale, en boucle hors-pile, des oscillations hydrodynamiques survenant dans les reacteurs a ebullition. L'etude a ete effectuee a la pression atmospherique et a une pression voisine de 8 atmospheres dans des canaux chauffes electriquement a puissance imposee constante et uniforme. Dans les essais a 8 atmospheres le canal etait un tube circulaire de diametre interieur 6 mm environ. A 1 atmosphere le canal etait de section annulaire 10 * 20 mm avec un tube interieur chauffant et un tube exterieur en pyrex. Le fonctionnement etait possible

  19. Rock-fall Hazard In The Yosemite Valley, California

    Science.gov (United States)

    Guzzetti, F.; Reichenbach, P.; Wieczorek, G. F.

    Rock slides and rock falls are the most frequent slope movements in Yosemite Na- tional Park, California. In historical time (1851-2001), more than 400 rock falls and rock slides have been documented in the valley, and some of them have been mapped in detail. We present the preliminary results of an attempt to assess rockfall hazard in the Yosemite Valley using STONE, a 3-dimensional rock-fall simulation computer program. The software computes 3-dimensional rock-fall trajectories starting from a digital terrain model (DTM), the location of rock-fall release points (source areas), and maps of the dynamic rolling coefficient and of the coefficients of normal and tan- gential energy restitution. For each DTM cell the software also calculates the number of rock falls passing through the cell, the maximum rock-fall velocity and the maxi- mum flying height. For the Yosemite Valley, a DTM with a ground resolution of 10 x 10 m was prepared using topographic contour lines from USGS 1:24,000-scale maps. Rock-fall release points were identified as DTM cells having a slope steeper than 60 degrees, an assumption based on the location of historical rock falls. Maps of the nor- mal and tangential energy restitution coefficients and of the rolling friction coefficient were produced from a surficial geologic map. The availability of historical rock falls mapped in detail allowed us to check the computer program performance and to cali- brate the model parameters. Visual and statistical comparison of the model results with the mapped rock falls confirmed the accuracy of the model. The model results are also compared with a geomorphic assessment of rock-fall hazard based on potential energy referred to as a "shadow angle" approach, recently completed for the Yosemite Valley.

  20. ONKALO rock mechanics model (RMM) - Version 2.0

    International Nuclear Information System (INIS)

    Moenkkoenen, H.; Hakala, M.; Paananen, M.; Laine, E.

    2012-02-01

    The Rock Mechanics Model of the ONKALO rock volume is a description of the significant features and parameters related to rock mechanics. The main objective is to develop a tool to predict the rock properties, quality and hence the potential for stress failure which can then be used for continuing design of the ONKALO and the repository. This is the second implementation of the Rock Mechanics Model and it includes sub-models of the intact rock strength, in situ stress, thermal properties, rock mass quality and properties of the brittle deformation zones. Because of the varying quantities of available data for the different parameters, the types of presentations also vary: some data sets can be presented in the style of a 3D block model but, in other cases, a single distribution represents the whole rock volume hosting the ONKALO. (orig.)

  1. Fracture characteristics in Japanese rock

    International Nuclear Information System (INIS)

    Ijiri, Yuji; Sawada, Atsushi; Akahori, Kuniaki

    1999-11-01

    It is crucial for the performance assessment of geosphere to evaluate the characteristics of fractures that can be dominant radionuclide migration pathways from a repository to biosphere. This report summarizes the characteristics of fractures obtained from broad literature surveys and the fields surveys at the Kamaishi mine in northern Japan and at outcrops and galleries throughout the country. The characteristics of fractures described in this report are fracture orientation, fracture shape, fracture frequency, fracture distribution in space, transmissivity of fracture, fracture aperture, fracture fillings, alteration halo along fracture, flow-wetted surface area in fracture, and the correlation among these characteristics. Since granitic rock is considered the archetype fractured media, a large amount of fracture data is available in literature. In addition, granitic rock has been treated as a potential host rock in many overseas programs, and has JNC performed a number of field observations and experiments in granodiorite at the Kamaishi mine. Therefore, the characteristics of fractures in granitic rock are qualitatively and quantitatively clarified to some extent in this report, while the characteristics of fractures in another rock types are not clarified. (author)

  2. Hot dry rock heat mining

    International Nuclear Information System (INIS)

    Duchane, D.V.

    1992-01-01

    Geothermal energy utilizing fluids from natural sources is currently exploited on a commercial scale at sites around the world. A much greater geothermal resource exists, however, in the form of hot rock at depth which is essentially dry. This hot dry rock (HDR) resource is found almost everywhere, but the depth at which usefully high temperatures are reached varies from place to place. The technology to mine the thermal energy from HDR has been under development for a number of years. Using techniques adapted from the petroleum industry, water is pumped at high pressure down an injection well to a region of usefully hot rock. The pressure forces open natural joints to form a reservoir consisting of a small amount of water dispensed in a large volume of hot rock. This reservoir is tapped by second well located at some distance from the first, and the heated water is brought to the surface where its thermal energy is extracted. The same water is then recirculated to mine more heat. Economic studies have indicated that it may be possible to produce electricity at competitive prices today in regions where hot rock is found relatively close to the surface

  3. Impact of catheter ablation with remote magnetic navigation on procedural outcomes in patients with persistent and long-standing persistent atrial fibrillation

    DEFF Research Database (Denmark)

    Jin, Qi; Pehrson, Steen; Jacobsen, Peter Karl

    2015-01-01

    with RMN. METHODS: A total of 313 patients (275 male, age 59 ± 9.5 years) with PsAF (187/313) or L-PsAF (126/313) undergoing ablation using RMN were included. Patients' disease history, pulmonary venous anatomy, left atrial (LA) volume, procedure time, mapping plus ablation time, radiofrequency (RF...

  4. Integration of rock typing methods for carbonate reservoir characterization

    International Nuclear Information System (INIS)

    Aliakbardoust, E; Rahimpour-Bonab, H

    2013-01-01

    Reservoir rock typing is the most important part of all reservoir modelling. For integrated reservoir rock typing, static and dynamic properties need to be combined, but sometimes these two are incompatible. The failure is due to the misunderstanding of the crucial parameters that control the dynamic behaviour of the reservoir rock and thus selecting inappropriate methods for defining static rock types. In this study, rock types were defined by combining the SCAL data with the rock properties, particularly rock fabric and pore types. First, air-displacing-water capillary pressure curues were classified because they are representative of fluid saturation and behaviour under capillary forces. Next the most important rock properties which control the fluid flow and saturation behaviour (rock fabric and pore types) were combined with defined classes. Corresponding petrophysical properties were also attributed to reservoir rock types and eventually, defined rock types were compared with relative permeability curves. This study focused on representing the importance of the pore system, specifically pore types in fluid saturation and entrapment in the reservoir rock. The most common tests in static rock typing, such as electrofacies analysis and porosity–permeability correlation, were carried out and the results indicate that these are not appropriate approaches for reservoir rock typing in carbonate reservoirs with a complicated pore system. (paper)

  5. Core Cutting Test with Vertical Rock Cutting Rig (VRCR)

    Science.gov (United States)

    Yasar, Serdar; Osman Yilmaz, Ali

    2017-12-01

    Roadheaders are frequently used machines in mining and tunnelling, and performance prediction of roadheaders is important for project economics and stability. Several methods were proposed so far for this purpose and, rock cutting tests are the best choice. Rock cutting tests are generally divided into two groups which are namely, full scale rock cutting tests and small scale rock cutting tests. These two tests have some superiorities and deficiencies over themselves. However, in many cases, where rock sampling becomes problematic, small scale rock cutting test (core cutting test) is preferred for performance prediction, since small block samples and core samples can be conducted to rock cutting testing. Common problem for rock cutting tests are that they can be found in very limited research centres. In this study, a new mobile rock cutting testing equipment, vertical rock cutting rig (VRCR) was introduced. Standard testing procedure was conducted on seven rock samples which were the part of a former study on cutting rocks with another small scale rock cutting test. Results showed that core cutting test can be realized successfully with VRCR with the validation of paired samples t-test.

  6. Study of some properties of zirconium phosphate; Etude de quelques proprietes du phosphate de zirconium

    Energy Technology Data Exchange (ETDEWEB)

    Prospert, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1963-05-01

    Zirconium phosphate has been studied with a view to using it as an ion exchanger: the first objective was to develop a method of preparation easy to apply and also reproducible. To this end, several tests were carried out varying the molar ratios of phosphorus and of zirconium. Some physical properties such as the diffraction of X-rays were examined. The work then involved certain chemical properties, particularly the percentages of free water and structural water given by the loss on calcination, the Karl-Fisher method and the weight losses by thermogravimetry. Finally an attempts was made to apply the exchanger to the separation of alkaline ions. The static tests showed that the order of fixation of these ions was Cs{sup +} > Rb{sup +} >> K{sup +} > Na{sup +}. Tests with columns showed that Na{sup +} and K{sup +} were easily separable, as was the Rb{sup +}-Cs{sup +} mixture, this last pair being fairly difficult to dissociate. (author) [French] Le phosphate de zirconium a ete etudie en vue de son utilisation comme echangeur d'ions: le premier but a atteindre a ete de mettre au point une preparation pouvant se reveler facilement utilisable ainsi qu'aisement reproductible. A cet effet, plusieurs essais ont ete effectues en faisant varier les rapports molaires du phosphore et du zirconium. Quelques proprietes physiques, telle la diffraction des rayons X, ont ete abordees. Ensuite, l'etude a porte sur certaines proprietes chimiques, particulierement les pourcentages d'eau libre et d'eau de structure par des pertes au feu, utilisation de la methode de Karl-Fisher, ainsi que des pertes de poids a la thenmobalance. Enfin, on a tente d'utiliser l'echangeur a la separation des ions alcalins. Les etudes statiques ont permis de constater que l'ordre de fixation de ces ions etait Cs{sup +} > Rb{sup +} >> K{sup +} > Na{sup +}. Les essais effectues en colonne ont montre que Na{sup +} et K{sup +} etaient aisement separables entre eux, ainsi que du couple Rb{sup +}-Cs{sup +}, ce

  7. Investigation of block foundations resting on soil–rock and rock–rock media under coupled vibrations

    Directory of Open Access Journals (Sweden)

    Renuka Darshyamkar

    2017-04-01

    Full Text Available In the present study, the dynamic response of block foundations of different equivalent radius to mass (Ro/m ratios under coupled vibrations is investigated for various homogeneous and layered systems. The frequency-dependent stiffness and damping of foundation resting on homogeneous soils and rocks are determined using the half-space theory. The dynamic response characteristics of foundation resting on the layered system considering rock–rock combination are evaluated using finite element program with transmitting boundaries. Frequencies versus amplitude responses of block foundation are obtained for both translational and rotational motion. A new methodology is proposed for determination of dynamic response of block foundations resting on soil–rock and weathered rock–rock system in the form of equations and graphs. The variations of dimensionless natural frequency and dimensionless resonant amplitude with shear wave velocity ratio are investigated for different thicknesses of top soil/weathered rock layer. The dynamic behaviors of block foundations are also analyzed for different rock–rock systems by considering sandstone, shale and limestone underlain by basalt. The variations of stiffness, damping and amplitudes of block foundations with frequency are shown in this study for various rock–rock combinations. In the analysis, two resonant peaks are observed at two different frequencies for both translational and rotational motion. It is observed that the dimensionless resonant amplitudes decrease and natural frequencies increase with increase in shear wave velocity ratio. Finally, the parametric study is performed for block foundations with dimensions of 4 m × 3 m × 2 m and 8 m × 5 m × 2 m by using generalized graphs. The variations of natural frequency and peak displacement amplitude are also studied for different top layer thicknesses and eccentric moments.

  8. Respirable dust measured downwind during rock dust application.

    Science.gov (United States)

    Harris, M L; Organiscak, J; Klima, S; Perera, I E

    2017-05-01

    The Pittsburgh Mining Research Division of the U.S. National Institute for Occupational Safety and Health (NIOSH) conducted underground evaluations in an attempt to quantify respirable rock dust generation when using untreated rock dust and rock dust treated with an anticaking additive. Using personal dust monitors, these evaluations measured respirable rock dust levels arising from a flinger-type application of rock dust on rib and roof surfaces. Rock dust with a majority of the respirable component removed was also applied in NIOSH's Bruceton Experimental Mine using a bantam duster. The respirable dust measurements obtained downwind from both of these tests are presented and discussed. This testing did not measure miners' exposure to respirable coal mine dust under acceptable mining practices, but indicates the need for effective continuous administrative controls to be exercised when rock dusting to minimize the measured amount of rock dust in the sampling device.

  9. Brushed Target on Rock 'Champagne' in Gusev Crater

    Science.gov (United States)

    2005-01-01

    NASA's Mars Exploration Rover Spirit took this microscopic image of a target called 'Bubbles' on a rock called 'Champagne' after using its rock abrasion tool to brush away a coating of dust. The circular brushed area is about 5 centimeters (2 inches) across. This rock is different from rocks out on the plains of Gusev Crater but is similar to other rocks in this area of the 'Columbia Hills' in that it has higher levels of phosphorus. Plagioclase, a mineral commonly found in igneous rocks, is also present in these rocks, according to analysis with the minature thermal emission spectrometer. By using the alpha particle X-ray spectrometer to collect data over multiple martian days, or sols, scientists are also beginning to get measurements of trace elements in these rocks. Spirit took the images that are combined into this mosaic on sol 354 (Dec. 30, 2004).

  10. Rock slope instabilities in Norway: First systematic hazard and risk classification of 22 unstable rock slopes

    Science.gov (United States)

    Böhme, Martina; Hermanns, Reginald L.; Oppikofer, Thierry; Penna, Ivanna

    2016-04-01

    Unstable rock slopes that can cause large failures of the rock-avalanche type have been mapped in Norway for almost two decades. Four sites have earlier been characterized as high-risk objects based on expertise of few researchers. This resulted in installing continuous monitoring systems and set-up of an early-warning system for those four sites. Other unstable rock slopes have not been ranked related to their hazard or risk. There are ca. 300 other sites known of which 70 sites were installed for periodic deformation measurements using multiple techniques (Global Navigation Satellite Systems, extensometers, measurement bolts, and others). In 2012 a systematic hazard and risk classification system for unstable rock slopes was established in Norway and the mapping approach adapted to that in 2013. Now, the first 22 sites were classified for hazard, consequences and risk using this classification system. The selection of the first group of sites to be classified was based on an assumed high hazard or risk and importance given to the sites by Norwegian media and the public. Nine of the classified 22 unstable rock slopes are large sites that deform inhomogeneously or are strongly broken up in individual blocks. This suggests that different failure scenarios are possible that need to be analyzed individually. A total of 35 failure scenarios for those nine unstable rock slopes were considered. The hazard analyses were based on 9 geological parameters defined in the classification system. The classification system will be presented based on the Gamanjunni unstable rock slope. This slope has a well developed back scarp that exposes 150 m preceding displacement. The lateral limits of the unstable slope are clearly visible in the morphology and InSAR displacement data. There have been no single structures observed that allow sliding kinematically. The lower extend of the displacing rock mass is clearly defined in InSAR data and by a zone of higher rock fall activity. Yearly

  11. Hierarchic Analysis Method to Evaluate Rock Burst Risk

    Directory of Open Access Journals (Sweden)

    Ming Ji

    2015-01-01

    Full Text Available In order to reasonably evaluate the risk of rock bursts in mines, the factors impacting rock bursts and the existing grading criterion on the risk of rock bursts were studied. By building a model of hierarchic analysis method, the natural factors, technology factors, and management factors that influence rock bursts were analyzed and researched, which determined the degree of each factor’s influence (i.e., weight and comprehensive index. Then the grade of rock burst risk was assessed. The results showed that the assessment level generated by the model accurately reflected the actual risk degree of rock bursts in mines. The model improved the maneuverability and practicability of existing evaluation criteria and also enhanced the accuracy and science of rock burst risk assessment.

  12. Lead isotope analyses of standard rock samples

    International Nuclear Information System (INIS)

    Koide, Yoshiyuki; Nakamura, Eizo

    1990-01-01

    New results on lead isotope compositions of standard rock samples and their analytical procedures are reported. Bromide form anion exchange chromatography technique was adopted for the chemical separation lead from rock samples. The lead contamination during whole analytical procedure was low enough to determine lead isotope composition of common natural rocks. Silica-gel activator method was applied for emission of lead ions in the mass spectrometer. Using the data reduction of 'unfractionated ratios', we obtained good reproducibility, precision and accuracy on lead isotope compositions of NBS SRM. Here we present new reliable lead isotope compositions of GSJ standard rock samples and USGS standard rock, BCR-1. (author)

  13. Fósforo num Cambissolo cultivado com cana-de-açúcar por longo tempo: II - análise de ácidos húmicos por RMN 31P Phosphorus in an Inceptsoil under long-term sugarcane: II - humic acid analysis by NMR 31P

    Directory of Open Access Journals (Sweden)

    Jader Galba Busato

    2005-12-01

    Full Text Available Sistemas de manejo da lavoura de cana-de-açúcar que favoreçam a matéria orgânica do solo podem aumentar o conteúdo de nutrientes disponíveis e diminuir a necessidade de aplicação de fertilizantes industriais. Apesar da importância dos componentes orgânicos no fornecimento de P, pouco se conhece sobre a sua dinâmica em ambientes tropicais. O objetivo deste trabalho foi identificar, por meio da ressonância magnética nuclear (RMN 31P, as espécies de P nos ácidos húmicos de um Cambissolo Háplico Ta eutrófico vértico, localizado no Município de Campos dos Goytacazes, norte do Estado do Rio de Janeiro, e cultivado com cana-de-açúcar com preservação do palhiço e adição de vinhaça por longo tempo. Por meio da análise de RMN 31P foi possível observar acúmulo de P orgânico em formas mais facilmente mineralizadas nas áreas com preservação de matéria orgânica, tal como P em ligações diésteres. Nas áreas de cana queimada, houve maior participação de espécies orgânicas mais estáveis, como o ortofosfato em ligações monoésteres. Os resultados da espectroscopia de RMN 31P mostram que, nas áreas com maior aporte de resíduo orgânico (i.e., cana crua e cana queimada com adição de vinhaça, os ácidos húmicos constituem uma reserva importante de P orgânico prontamente disponível. Já, nas áreas de cana queimada, o acúmulo de P orgânico recalcitrante nos ácidos húmicos indica utilização do P-lábil das substâncias húmicas como fonte importante para nutrição das plantas.Crop management systems that favor soil organic matter can improve the available nutrient content for plants and reduce the use of industrial fertilizer. Despite the importance of organic compounds as a P source, little is known about its dynamics in tropical environments. The objective of this study was to identify organic P species present in humic acids by NMR 31P analysis in a fine clay Fluventic Eutrochrepts in Campos dos

  14. Distribution of Pa-231 and Ra-226 in rock. An indicator of rock matrix diffusion

    International Nuclear Information System (INIS)

    Saarinen, L.; Suksi, J.

    1995-01-01

    Distribution of Ra-226 and Pa-231 in rock has been studied to find signatures that may be attributed to diffusion. The idea of studying these nuclides originated from the need to obtain interpretative support to the findings of U movement in rock. Concentration profiles of Ra-226 and Pa-231 with other U series nuclides were measured across the secondary U accumulations observed in altered rock close to a fracture in the vicinity of U deposit, and in a radioactivity anomaly. (27 refs., 10 figs., 2 tabs.)

  15. Experimental study of the radio-active contamination of certain cultivated plants by irrigation water; Etude experimentale de la contamination radioactive par l'eau d'irrigation de certaines plantes cultivees

    Energy Technology Data Exchange (ETDEWEB)

    Michon, G [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires; Barbier, G; Le Blaye, P; Brossard, M [Station Centrale d' Agronomie, 78 - Versailles (France); Fioramonti, S; Marty, J R [Station Agronomique de Toulouse, 31 (France); Benard, P; Flanzy, M [Station Centrale de Technologie des Produits Vegetaux, 11 - Narbonne (France); Delas, J; Delmas, J; Demias, Ch [Station d' Agronomie de Bordeaux (Pont de la Maye), 33 (France); Huguet, C [Station Agronomique d' Avignon, 84 (France)

    1964-07-01

    This report follows on to the CEA reports no 1860 and 2159 and gives the results obtained during the years 1961 and 1962. These results confirm for the most part those obtained previously and deal also with a larger variety of vegetables. Vines and artificial prairies were also dealt with during the course of this work. The large dispersion of the limiting values of the coefficient r (the ratio between the amount of radio-elements in a kilogram of product harvested, to the amount of radio-elements present in a litre of irrigation water) with different types of soil, different plant types, etc... , makes it impossible to draw any general conclusions. Each case of rejection requires a special study of which the outlive is given. At all events it is to be expected that in the majority of cases these studies will lead to a decrease in the norms now in force. (authors) [French] Ce rapport fait suite aux rapports CEA no 1860 et 2159 et rapporte les resultats obtenus pendant les annees 1961 et 1962. Ces resultats confirment dans l'ensemble ceux precedemment obtenus tout en augmentant la variete des legumes etudies. La vigne et les prairies artificielles ont egalement fait l'objet d'etudes. La grande dispersion des valeurs limites du coefficient r (rapport entre la quantite de radioelements dans un kg de produits recoltes a la quantite de radioelements presente dans un litre d'eau d'irrigation) en rapport avec la nature des sols, le type vegetal, etc.., ne permet pas de degager de conclusions generales. Chaque cas de rejet necessite une etude particuliere dont le schema est donne. En tout etat de cause l'on doit s'attendre a ce que dans la plupart des cas ces etudes conduisent a une diminution des normes actuellement utilisees. (auteurs)

  16. Unsupervised feature learning for autonomous rock image classification

    Science.gov (United States)

    Shu, Lei; McIsaac, Kenneth; Osinski, Gordon R.; Francis, Raymond

    2017-09-01

    Autonomous rock image classification can enhance the capability of robots for geological detection and enlarge the scientific returns, both in investigation on Earth and planetary surface exploration on Mars. Since rock textural images are usually inhomogeneous and manually hand-crafting features is not always reliable, we propose an unsupervised feature learning method to autonomously learn the feature representation for rock images. In our tests, rock image classification using the learned features shows that the learned features can outperform manually selected features. Self-taught learning is also proposed to learn the feature representation from a large database of unlabelled rock images of mixed class. The learned features can then be used repeatedly for classification of any subclass. This takes advantage of the large dataset of unlabelled rock images and learns a general feature representation for many kinds of rocks. We show experimental results supporting the feasibility of self-taught learning on rock images.

  17. Heating effects in Rio Blanco rock

    International Nuclear Information System (INIS)

    Taylor, R.W.; Bowen, D.W.; Rossler, P.E.

    1975-01-01

    Samples of ''sandstone'' from near the site of the upper Rio Blanco nuclear explosion were heated in the laboratory at temperatures between 600 and 900 0 C. The composition and amount of noncondensable (dry) gas released were measured and compared to the amount and composition of gas found underground following the explosion. The gas released from the rock heated in the laboratory contained approximately 80 percent CO 2 and 10 percent H 2 ; the balance was CO and CH 4 . With increasing temperature, the amounts of CO 2 , CO, and H 2 released increased. The composition of gas released by heating Rio Blanco rock in the laboratory is similar to the composition of gas found after the nuclear explosion except that it contains less natural gas (CH 4 , C 2 H 6 . . .). The amount of noncondensable gas released by heating the rock increases from approximately 0.1 mole/kg of rock at 600 0 C to 0.9 mole/kg at 900 0 C. Over 90 percent of the volatile components of the rock are released in less than 10 h at 900 0 C. A comparison of the amount of gas released by heating rock in the laboratory to the amount of gas released by the heat of the Rio Blanco nuclear explosion suggests that the explosion released the volatile material from about 0.42 mg of rock per joule of explosive energy (1700 to 1800 tonnes per kt). (auth)

  18. Rock shape, restitution coefficients and rockfall trajectory modelling

    Science.gov (United States)

    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.

  19. A system of nomenclature for rocks in Olkiluoto

    International Nuclear Information System (INIS)

    Mattila, J.

    2006-06-01

    Due to international interest in the Finnish deep repository project at Olkiluoto (SW Finland) and the need for collaboration between scientists involved in site investigations for the disposal of spent nuclear fuel in other countries, a well-documented system of rock nomenclature is required, based on existing classification schemes and international recommendations. The BGS (British Geological Survey) rock classification scheme is the most comprehensive rock classification scheme and the basic principles behind it are utilised for the system of nomenclature for rocks in Olkiluoto. The BGS classification system is based on the use of descriptive names and a clear hierarchy, making it possible to classify rocks at different levels depending on the specific goals of the study, the level of available information, and the expertise of the user. Each rock type is assigned a root name, which is based on structural and textural characteristics or modal compositions of the rock and the root names are refined with qualifier terms as prefixes. Qualifier terms refer to the structure or modal composition of the rock. The bedrock at the Olkiluoto site consists of metamorphic and igneous rocks. The metamorphic rocks consist of migmatitic gneisses and (non-migmatitic) gneisses, which are further divided according to their structural characteristics and modal compositions, the former into stromatic, veined, diatexitic gneisses, the latter into mica, quartz, mafic and TGG gneisses. Igneous rocks consist of pegmatitic granites, K-feldspar porphyry and diabases. (orig.)

  20. A Review of Rock Bolt Monitoring Using Smart Sensors

    Directory of Open Access Journals (Sweden)

    Gangbing Song

    2017-04-01

    Full Text Available Rock bolts have been widely used as rock reinforcing members in underground coal mine roadways and tunnels. Failures of rock bolts occur as a result of overloading, corrosion, seismic burst and bad grouting, leading to catastrophic economic and personnel losses. Monitoring the health condition of the rock bolts plays an important role in ensuring the safe operation of underground mines. This work presents a brief introduction on the types of rock bolts followed by a comprehensive review of rock bolt monitoring using smart sensors. Smart sensors that are used to assess rock bolt integrity are reviewed to provide a firm perception of the application of smart sensors for enhanced performance and reliability of rock bolts. The most widely used smart sensors for rock bolt monitoring are the piezoelectric sensors and the fiber optic sensors. The methodologies and principles of these smart sensors are reviewed from the point of view of rock bolt integrity monitoring. The applications of smart sensors in monitoring the critical status of rock bolts, such as the axial force, corrosion occurrence, grout quality and resin delamination, are highlighted. In addition, several prototypes or commercially available smart rock bolt devices are also introduced.

  1. A Review of Rock Bolt Monitoring Using Smart Sensors.

    Science.gov (United States)

    Song, Gangbing; Li, Weijie; Wang, Bo; Ho, Siu Chun Michael

    2017-04-05

    Rock bolts have been widely used as rock reinforcing members in underground coal mine roadways and tunnels. Failures of rock bolts occur as a result of overloading, corrosion, seismic burst and bad grouting, leading to catastrophic economic and personnel losses. Monitoring the health condition of the rock bolts plays an important role in ensuring the safe operation of underground mines. This work presents a brief introduction on the types of rock bolts followed by a comprehensive review of rock bolt monitoring using smart sensors. Smart sensors that are used to assess rock bolt integrity are reviewed to provide a firm perception of the application of smart sensors for enhanced performance and reliability of rock bolts. The most widely used smart sensors for rock bolt monitoring are the piezoelectric sensors and the fiber optic sensors. The methodologies and principles of these smart sensors are reviewed from the point of view of rock bolt integrity monitoring. The applications of smart sensors in monitoring the critical status of rock bolts, such as the axial force, corrosion occurrence, grout quality and resin delamination, are highlighted. In addition, several prototypes or commercially available smart rock bolt devices are also introduced.

  2. Nagra technical report 14-02, Geological basics - Dossier VI - Barrier properties of proposed host rock sediments and neighbouring rock

    International Nuclear Information System (INIS)

    Gautschi, A.; Deplazes, G.; Traber, D.; Marschall, P.; Mazurek, M.; Gimmi, T.; Maeder, U.

    2014-01-01

    This dossier is the sixth of a series of eight reports concerning the safety and technical aspects of locations for the disposal of radioactive wastes in Switzerland. It discusses the barrier properties of the proposed host rock sediments and neighbouring rock layers. The mineralogical composition of the host rocks are discussed as are their pore densities and hydrological properties. Diffusion aspects are discussed. The aquifer systems in the proposed depository areas and their classification are looked at. The barrier properties of the host rocks and those of neighbouring sediments are discussed. Finally, modelling concepts and parameters for the transport of radionuclides in the rocks are discussed

  3. I. Some results from a field investigation of thermo-mechanical loading of a rock mass when heaters are emplaced in the rock

    International Nuclear Information System (INIS)

    Hood, M.

    1979-01-01

    Results are presented of a field experiment to monitor the response of a rock mass to thermomechanical loading from electrically heated canisters emplaced in the rock at a depth of 340 m. Measurements made to date of temperature, displacement, and stress fields indicate that heat is transferred through the rock mainly by conduction; discontinuities within the rock mass have a minimal effect on the heat flow. Displacements within the rock from thermal expansion are shown to be much less than those predicted by linear thermoelastic theory. A plausible, though not complete, reason for these reduced displacements is the absorption of the initial rock expansions into discontinuities within the rock mass. Difficulties have been experienced in obtaining reliable stress measurement data using borehole deformation gauges to monitor changes in rock stress. Some data have been obtained and are being analyzed. Rock decrepitation in the heater boreholes is discussed

  4. Clinical and symptomatological study of pigs subjected to a lethal dose of integral gamma irradiation; Etude clinique et symptomatologique chez le porc soumis a une irradiation gamma totale a dose letale

    Energy Technology Data Exchange (ETDEWEB)

    Vaiman, M; Guenet, J -L; Maas, J; Nizza, P

    1966-05-01

    Results are reported from a clinical and haematological study on a Corsican species of pigs wholly exposed to an approximately lethal dose of {gamma} radiation. The aim of this work was to examine the changes in the irradiation syndrome of irradiation for pigs to make it thus possible to devise further experiments, in particular in the therapeutic field. The dose received was 285 rads (measured as the absorption in the vertical antero-posterior medial plane). Data are presented on cyto-haematological changes in the blood circulating immediately after irradiation, and followed up to death, and changes in the medullary cytology after irradiation. The clinical picture of lethal radiation injury in swine is described. (authors) [French] Les auteurs rapportent les resultats d'une etude clinique et hematologique chez des porcs de race corse irradies in toto a dose sensiblement letale. Le but de cette etude etait de connaitre l'evolution du syndrome aigu d'irradiation chez le porc et de permettre ainsi le developpement d'experimentations ulterieures, en particulier dans le domaine therapeutique. La dose delivree etait de 285 rad (en dose absorbee au niveau du plan median vertical anteroposterieur. L'etude a porte essentiellement: 1. Sur les modifications cyclo-hematologiques du sang circulant immediatement apres l'irradiation, pour les differentes lignees cellulaires; l'evolution de ces modifications a ete notee jusqu'a la mort; 2. Sur les modifications de la cytologie medullaire apres irradiation (evolution du myelogramme et essai d'evaluation de la cellularite de la moelle osseuse);: 3. Sur les signes cliniques, d'ailleurs tres discrets, observes chez les porcs apres irradiation. (auteurs)

  5. Clinical and symptomatological study of pigs subjected to a lethal dose of integral gamma irradiation; Etude clinique et symptomatologique chez le porc soumis a une irradiation gamma totale a dose letale

    Energy Technology Data Exchange (ETDEWEB)

    Vaiman, M.; Guenet, J.-L.; Maas, J.; Nizza, P

    1966-05-01

    Results are reported from a clinical and haematological study on a Corsican species of pigs wholly exposed to an approximately lethal dose of {gamma} radiation. The aim of this work was to examine the changes in the irradiation syndrome of irradiation for pigs to make it thus possible to devise further experiments, in particular in the therapeutic field. The dose received was 285 rads (measured as the absorption in the vertical antero-posterior medial plane). Data are presented on cyto-haematological changes in the blood circulating immediately after irradiation, and followed up to death, and changes in the medullary cytology after irradiation. The clinical picture of lethal radiation injury in swine is described. (authors) [French] Les auteurs rapportent les resultats d'une etude clinique et hematologique chez des porcs de race corse irradies in toto a dose sensiblement letale. Le but de cette etude etait de connaitre l'evolution du syndrome aigu d'irradiation chez le porc et de permettre ainsi le developpement d'experimentations ulterieures, en particulier dans le domaine therapeutique. La dose delivree etait de 285 rad (en dose absorbee au niveau du plan median vertical anteroposterieur. L'etude a porte essentiellement: 1. Sur les modifications cyclo-hematologiques du sang circulant immediatement apres l'irradiation, pour les differentes lignees cellulaires; l'evolution de ces modifications a ete notee jusqu'a la mort; 2. Sur les modifications de la cytologie medullaire apres irradiation (evolution du myelogramme et essai d'evaluation de la cellularite de la moelle osseuse);: 3. Sur les signes cliniques, d'ailleurs tres discrets, observes chez les porcs apres irradiation. (auteurs)

  6. Test procedures for salt rock

    International Nuclear Information System (INIS)

    Dusseault, M.B.

    1985-01-01

    Potash mining, salt mining, design of solution caverns in salt rocks, disposal of waste in salt repositories, and the use of granular halite backfill in underground salt rock mines are all mining activities which are practised or contemplated for the near future. Whatever the purpose, the need for high quality design parameters is evident. The authors have been testing salt rocks in the laboratory in a number of configurations for some time. Great care has been given to the quality of sample preparation and test methodology. This paper describes the methods, presents the elements of equipment design, and shows some typical results

  7. Fault rocks and uranium mineralization

    International Nuclear Information System (INIS)

    Tong Hangshou.

    1991-01-01

    The types of fault rocks, microstructural characteristics of fault tectonite and their relationship with uranium mineralization in the uranium-productive granite area are discussed. According to the synthetic analysis on nature of stress, extent of crack and microstructural characteristics of fault rocks, they can be classified into five groups and sixteen subgroups. The author especially emphasizes the control of cataclasite group and fault breccia group over uranium mineralization in the uranium-productive granite area. It is considered that more effective study should be made on the macrostructure and microstructure of fault rocks. It is of an important practical significance in uranium exploration

  8. Rock Magnetic Properties of Remagnetised Devonian and Carboniferous Carbonate and Clastic Rocks From The NE Rhenish Massif, Germany

    Science.gov (United States)

    Zwing, A.; Matzka, J.; Bachtadse, V.; Soffel, H. C.

    Previous studies on remagnetised carbonate rocks from the North American and Eu- ropean Variscides reported characteristic rock magnetic properties which are thought to be diagnostic for a chemical remagnetisation event. Their hysteresis properties with high ratios of Mrs/Ms and Hcr/Hc indicate the presence of a mixture of single-domain and superparamagnetic magnetite (Jackson, et al. 1990). In order to test if this fin- gerprint can be identified in remagnetised carbonate and clastic rocks from the NE Rhenish Massif, Germany, a series of rock magnetic experiments has been carried out. The hysteresis properties of the remagnetised clastic rocks indicate the domi- nance of large MD particles, as can be expected for detrital sediments. The carbon- ates yield significantly higher ratios of Mrs/Ms and Hcr/Hc than the clastic rocks, but only partly correspond to the characteristic properties of remagnetised carbon- ates described above. The latter might be attributed to detrital input into the carbonate platforms. Additional low-temperature remanence measurements show a wide vari- ety of phenomena, including Verwey transitions and indications for the presence of superparamagnetic grains. However, the low-temperature experiments do not allow a straightforward discrimination between the clastic and carbonate rocks and suggest more complex magnetomineralogies than expected from the hysteresis measurements alone.

  9. Radiation transport in statistically inhomogeneous rocks

    International Nuclear Information System (INIS)

    Lukhminskij, B.E.

    1975-01-01

    A study has been made of radiation transfer in statistically inhomogeneous rocks. Account has been taken of the statistical character of rock composition through randomization of density. Formulas are summarized for sigma-distribution, homogeneous density, the Simpson and Cauchy distributions. Consideration is given to the statistics of mean square ranges in a medium, simulated by the jump Markov random function. A quantitative criterion of rock heterogeneity is proposed

  10. Tectonic constraints on a deep-seated rock slide in weathered crystalline rocks

    Science.gov (United States)

    Borrelli, Luigi; Gullà, Giovanni

    2017-08-01

    Deep-seated rock slides (DSRSs), recognised as one of the most important mass wasting processes worldwide, involve large areas and cause several consequences in terms of environmental and economic damage; they result from a complex of controlling features and processes. DSRSs are common in Calabria (southern Italy) where the complex geo-structural setting plays a key role in controlling the geometry of the failure surface and its development. This paper describes an integrated multi-disciplinary approach to investigate a DSRS in Palaeozoic high-grade metamorphic rocks of the Sila Massif; it focuses on the definition of the internal structure and the predisposing factors of the Serra di Buda landslide near the town of Acri, which is a paradigm for numerous landslides in this area. An integrated interdisciplinary study based on geological, structural, and geomorphological investigations-including field observations of weathering grade of rocks, minero-petrographic characterisations, geotechnical investigations and, in particular, fifteen years of displacement monitoring-is presented. Stereoscopic analysis of aerial photographs and field observations indicate that the Serra di Buda landslide consists of two distinct compounded bodies: (i) an older and dormant body ( 7 ha) and (ii) a more recent and active body ( 13 ha) that overlies the previous one. The active landslide shows movement linked to a deep-seated translational rock slide (block slide); the velocity scale ranges from slow (1.6 m/year during paroxysmal stages) to extremely slow (affected by weathering processes that significantly reduce the rock strength and facilitate the extensive failure of the Serra di Buda landslide. Finally, the landslide's internal structure, according to geotechnical investigations and displacement monitoring, is proposed. The proposed approach and the obtained results can be generalised to typify other deep landslides in similar geological settings.

  11. Exact effective-stress rules in rock mechanics

    International Nuclear Information System (INIS)

    Berryman, J.G.

    1992-01-01

    The standard paradigm for analysis of rock deformation arises from postulating the existence of ''an equivalent homogeneous porous rock.'' However, data on the pore-pressure dependence of fluid permeability for some rocks cannot be explained using any equivalent homogeneous porous medium. In contrast, a positive result shows that deformation measurements on both high-porosity sandstones and low-porosity granites can be explained adequately in terms of an equivalent two-constituent model of porous rocks, for which exact results have recently been discovered

  12. Analysis of volcano rock from Canary islands

    International Nuclear Information System (INIS)

    Sitek, J.; Sedlackova, K.; Dekan, J.

    2013-01-01

    In this work we have analyzed the basalt rock from Lanzarote, which is the easternmost island of the Canary Islands lying in the Atlantic Ocean and has a volcanic origin. It was born through fiery eruptions and has solidified lava streams as well as extravagant rock formations. We compared our results with composition of basalt rocks from some other places on the Earth. Different iron oxides created on the volcanic rocks during their weathering on the Earth surface has been also analyzed. (authors)

  13. Castor and Pollux - shielded cells for studying fuel treatment processes; Castor et Pollux chaines blindees d'etudes de procedes de traitement de combustibles

    Energy Technology Data Exchange (ETDEWEB)

    Faudot, G; Bathellier, A [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1969-07-01

    CASTOR and POLLUX, two alpha, beta, gamma cells are described in the present paper. They are located in the CEN at Fontenay-aux-Roses (France). They are designed for improvement studies of the various aqueous separation processes used in irradiated fuels reprocessing plants. Located in the same air-tight steel encasement, they arc inter-connected by a pneumatic transfer. These two cells have a similar in-line conception and they include: a gamma shielding in lead of 10 cm of thickness; an inner air-tight box, made with stainless steel and plexiglas, is maintained in lowering in comparison to room pressure. Eleven Hobson model seven master-slave manipulators allow inner manipulations. Then the inner equipment is described briefly. (author) [French] Le present document decrit les cellules alpha, beta, gamma CASTOR et POLLUX edifiees au Centre d'Etudes Nucleaires de Fontenay-aux-Roses. Elles sont destinees aux etudes visant a l'amelioration des procedes de separation par voie aqueuse utilises dans les usines de retraitement des combustibles irradies. Ces deux chaines, implantees dans le meme caisson et reliees par convoyeur pneumatique, sont de conception identique et comprennent: une protection biologique constituee par 10 cm d'epaisseur de plomb; une enceinte interieure etanche alpha, en acier inoxidable et plexiglas, maintenue en depression. Des telemanipulateurs Hobson, modele 7, permettent les manipulations interieures. On decrit ensuite brievement les installations annexes. (auteur)

  14. Investigation of the porosity of rocks

    International Nuclear Information System (INIS)

    Hellmuth, K.H.; Siitari-Kauppi, M.

    1990-06-01

    Methods for characterizing the nature of rock porosity in conjunction with diffusion experiments, are amongst the primary tools used in repository-site selection investigations. At this time no experimental method, alone, is capable of giving an unambiguous picture of the narrow-aperture pore space in crystalline rock. Methods giving information on overall properties must be complemented by those having high spatial resolution; then the lateral distribution of porosity within the matrix and its association with particular mineral phases or features, such as microfissures, fissure fillings, weathered or altered mineral phases etc, and the identification of diffusion pathways in inhomogeneous rock matrices can be determined. Nonsorbing, nonelectrolytic tracers should be used when one wants to determine rock-typical properties of the internal porosity without interference of interactions with surfaces. Preliminary information on a new method fulfilling these criteria is given. Impregnating rock samples with methylmethacrylate labeled with carbon-14 which, after impregnation, was polymerized by gamma radiation, gave specimens that made preparation of sections suitable for quantification by autoradiographic methods easy. Diffusion experiments can be conducted so that labeled MMA diffuses out of rock specimens into inactive free, MMA. Additional information may be gained by leaching PMMA fractions of lower molecular weight from the matrix

  15. Gas migration in argillaceous rock

    International Nuclear Information System (INIS)

    Alonso, E. E.; Olivella, S.

    2007-01-01

    The intrinsic gas permeability of fractured argillaceous rocks depends on the current structure of micro-cracks and fissures of the rock. They are a consequence of the initial state and the subsequent deformations induced by stress and gas pressure changes. Stresses are also coupled with fluid pressures and, therefore, gas flow and mechanical behaviour are intensely coupled. Laboratory experiments, aimed at determining intrinsic permeability, show the relevant effect of volumetric deformations induced by isotropic, as well as deviatoric stress changes. The relevance, in practice, of the flow-mechanical coupling is illustrated by means of some results obtained during the performance of the drift scale test (DST) in fractured tuff in the Yucca Mountain facility. The technique of embedding discontinuities in continuum thermo-hydro-mechanical elements is capable of reproducing observed features of gas flow migration in clayey rocks. An example is described. It is believed that the developed approach provides a powerful computational procedure to handle complex gas phenomena in clayey rocks. (author)

  16. A crystallographic and spectroscopic study of crystal sites in the 'spinel' structure; Etude cristallographique et spectroscopique des sites cristallins dans la structure 'spinelle'

    Energy Technology Data Exchange (ETDEWEB)

    Drifford, M. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1967-06-15

    A crystallographic study on magnesium aluminates led to the determination of crystal site average distortion. A spectroscopic study of transition elements doped spinels gave the position of the doping element in tetrahedral (A) or octahedral (B) sites, and the local distortion of the latter. The comparison of average and local parameters points to differences in the behaviour of doping elements and shows the size of (A) sites are independent of the host crystal composition while the average size of (B) sites varies with the composition. (author) [French] Une etude cristallographique des aluminates de magnesium a permis de determiner la deformation moyenne des sites cristallins. Une etude spectroscopique des aluminates de magnesium dopes avec des elements de transition a permis de localiser les dopants entre les sites tetraedriques (A) et octaedriques (B) et d'etudier la deformation locale de ces sites. La comparaison entre les parametres moyens et locaux a caracterise le comportement du dopant et montre que les dimensions des sites (A) sont independantes de la composition de la matrice, alors que les caracteristiques geometriques moyennes des sites (B) varient continument avec la composition. (auteur)

  17. Rock burst prevention at steep seam mining

    Energy Technology Data Exchange (ETDEWEB)

    Efremov, G D

    1988-09-01

    At steep shield longwalls one method of preventing rock bursts is to avoid sharp angles during working. Stress in coal and rock body that appears when steep seams are worked where rock bursts occur at corners of set-up entries is discussed. The dynamic interaction between gas and rock pressure is assessed. Maintains that in order to avoid rock bursts at these places it is necessary to turn the protruding coal wall by 20-30 degrees towards the coal body to divert the action of shift forces. At the same time the face should also be inclined (by 10-15 degrees) to move the zones of increased stress away from the corner into the coal and rock body. Stress at workings with round cross-sections is 3-4 times lower than at square cross-sections. Recommendations are given that concern shearer loader operation (semi-spherical shape of the face), borehole drilling and water injection. Initial distance of 10-15 m between boreholes is suggested. 3 refs.

  18. Radwaste storage in crystalline rocks: a natural analog

    International Nuclear Information System (INIS)

    Brookins, D.G.; Abashian, M.S.; Cohen, L.H.; Wollenberg, H.A.

    1982-01-01

    The Eldora-Bryan Stock (Colorado) intruded the 1.4-1.6 billion year old metamorphic rocks of the Idaho Springs Formation 55 million years ago. The stock may be considered a giant analog of a radwaste form without canister or engineered backfill barriers. The authors' lanthanide studies show the following: (1) The intrusive rocks remained as a closed system. (2) Lanthanide/chondrite versus ionic radius plots show only local redistribution in the immediate contact zone, and that rocks in this zone have not gained lanthanides from the magma. (3) No whole rock perturbations for the lanthanides are noted at distances greater than 3 m from the contact. Stable oxygen isotopic variations show a narrow 9.0 +- 0.3 per mille range for the intrusive rocks and whole rock values from 7.6 to 10.0 per mille for the intruded rocks. The authors conclude: (1) The Idaho Springs Formation was not penetrated by hydrothermal fluids from the Eldora-Bryan magma except possibly on a local scale within 3 m of the contact. (2) The light lanthanides may be locally redistributed in the immediate contact zone, but without additions from the magma. (3) The oxygen isotopic data imply lack of hydrothermal fluids from the magma penetrating the intruded rocks, even in the highest temperature contact zones. Whole rock data imply closed system conditions for Rb, Sr, Th, U, Pb even where mineral ages have been lowered. Data for Co, Cr, Sc, Fe, Cs also indicate retention in whole rock systems and no exchange with the magma. The combined chemical, isotopic, petrographic and theoretical data and calculations indicate suitability of rocks of the Idaho Springs Formation, and thus of many types of crystalline rocks as well, for possible use for the storage of radioactive waste

  19. Uranium in the rock fragments from Lunar soil

    International Nuclear Information System (INIS)

    Komarov, A.N.; Sergeev, S.A.

    1983-01-01

    Uranium content and distribution in Lunar rock fragments 0.4-0.9 mm in size from ''Lunar-16+ -20, -24'' stations were studied by the method of autoradiography. Uranium is almost absent in rock-forming minerals and is concentrated in some accessory mineral. Uranium content in microgabro fragments from ''Lunar-20 and -24'' equals (0.0n - n.0)16 -6 g/g. Variations are not related to fragment representation. Radiogra-- phies of fragments from Lunar soil showed the uranium distribution from uniform (in glasses) to extremely nonuniform in some holocrystalline rocks. It was pointed out, that uranium micro distributions in Lunar and Earth (effusive and magmatic) rocks have common features. In both cases rock-forming minerals don't contain appreciable uranium amount in the form of isomorphic admixture; uranium is highly concentrated in some accessory minerais. The difference lies in tne absence of hydroxyl -containing secondary minerals, which are enriched with uranium on Earth, in Lunar rocks. ''Film'' uranium micromineralization, which occurs in rocks of the Earth along the boundaries of mineral grains is absent in Lunar rocks as well

  20. Compact rock material gas permeability properties

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Huanling, E-mail: whl_hm@163.com [Key Laboratory of Coastal Disaster and Defence, Ministry of Education, Hohai University, Nanjing 210098 (China); LML, University of Lille, Cite Scientifique, 59655 Villeneuve d’Ascq (France); Xu, Weiya; Zuo, Jing [Institutes of Geotechnical Engineering, Hohai University, Nanjing 210098 (China)

    2014-09-15

    Natural compact rocks, such as sandstone, granite, and rock salt, are the main materials and geological environment for storing underground oil, gas, CO{sub 2,} shale gas, and radioactive waste because they have extremely low permeabilities and high mechanical strengths. Using the inert gas argon as the fluid medium, the stress-dependent permeability and porosity of monzonitic granite and granite gneiss from an underground oil storage depot were measured using a permeability and porosity measurement system. Based on the test results, models for describing the relationships among the permeability, porosity, and confining pressure of rock specimens were analyzed and are discussed. A power law is suggested to describe the relationship between the stress-dependent porosity and permeability; for the monzonitic granite and granite gneiss (for monzonitic granite (A-2), the initial porosity is approximately 4.05%, and the permeability is approximately 10{sup −19} m{sup 2}; for the granite gneiss (B-2), the initial porosity is approximately 7.09%, the permeability is approximately 10{sup −17} m{sup 2}; and the porosity-sensitivity exponents that link porosity and permeability are 0.98 and 3.11, respectively). Compared with moderate-porosity and high-porosity rocks, for which φ > 15%, low-porosity rock permeability has a relatively lower sensitivity to stress, but the porosity is more sensitive to stress, and different types of rocks show similar trends. From the test results, it can be inferred that the test rock specimens’ permeability evolution is related to the relative particle movements and microcrack closure.

  1. Search for magnetic minerals in Martian rocks: Overview of the Rock Abrasion Tool (RAT) magnet investigation on Spirit and Opportunity

    DEFF Research Database (Denmark)

    Goetz, W.; Leer, K.; Gunnlaugsson, H.P.

    2008-01-01

    The Rock Abrasion Tool (RAT) on board the Mars Exploration Rovers (MER) is a grinding tool designed to remove dust coatings and/or weathering rinds from rocks and expose fresh rock material. Four magnets of different strengths that are built into the structure of the RAT have been attracting...... is interpreted as magnetite. The amount of abraded rock material adhering to the magnets varied strongly during the mission and is correlated in a consistent way to the amount of magnetite inferred from Mossbauer spectra for the corresponding rock. The RAT magnet experiment as performed on Opportunity also...

  2. Magnetic study of solid uranium-fluorine complexes; Contribution a l'etude magnetique de composes fluores solides de l'uranium

    Energy Technology Data Exchange (ETDEWEB)

    Dianoux, A.J. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1969-06-01

    A study of the magnetic susceptibility of uranium V fluorine complexes and of the magnetic resonance of fluorine atoms in uranium VI fluorine complexes has made it possible to put forward a structural model for these compounds for which it is impossible, because of the lack of suitable single crystals for X-ray diffraction work, to deduce the exact position of the fluorine atoms. It is shown that it is difficult to interpret the paramagnetism of uranium fluorides, because the uranium ions are in low-symmetry sites. A theoretical study of the magnetism of the U{sup V} ion in complex fluorides of the type M{sub 3}UF{sub 8} (M = NH{sub 4}, Na, Rb, Cs) leads to an interpretation based on a trigonal deformation of the eight fluorine atom structure surrounding the uranium atom. By applying a Hamiltonian spin formalism and making a systematic use of group theory, it is possible to present the susceptibility calculations very concisely. Study of the resonance and of the relaxation of the fluorine atoms in powdered uranium VI complex fluorides suggests a structural model in the case of NaUF{sub 7}. It is shown that the shape of the magnetic resonance absorption lines is strongly affected by the presence of large anisotropic chemical shifts. In the model proposed here, six fluorine atoms are linked to the uranium, atom by strongly covalent bonds in a deformed UF{sub 6} octahedral structure; the seventh fluorine atom remains ionic. The occurrence of a rotational movement of the octahedron is confirmed by a study of the longitudinal relaxation of the fluorine atoms, the activation energy being 0.46 eV. (author) [French] L'etude de la susceptibilite magnetique de complexes fluores d'uranium V et la resonance magnetique des fluors dans des complexes fluores d'uranium VI permettent de proposer un modele structural pour ces composes, ou la diffraction des rayons X, en l'absence de monocristaux convenables, est incapable de preciser la position des atomes de

  3. First Grinding of a Rock on Mars

    Science.gov (United States)

    2004-01-01

    The round, shallow depression in this image resulted from history's first grinding of a rock on Mars. The rock abrasion tool on NASA's Spirit rover ground off the surface of a patch 45.5 millimeters (1.8 inches) in diameter on a rock called Adirondack during Spirit's 34th sol on Mars, Feb. 6, 2004. The hole is 2.65 millimeters (0.1 inch) deep, exposing fresh interior material of the rock for close inspection with the rover's microscopic imager and two spectrometers on the robotic arm. This image was taken by Spirit's panoramic camera, providing a quick visual check of the success of the grinding. The rock abrasion tools on both Mars Exploration Rovers were supplied by Honeybee Robotics, New York, N.Y.

  4. Uranium endowments in phosphate rock

    Energy Technology Data Exchange (ETDEWEB)

    Ulrich, Andrea E., E-mail: andrea.ulrich@env.ethz.ch [Institute for Environmental Decisions (IED), Natural and Social Science Interface, ETH Zurich Universitässtrasse 22, 8092 Zurich (Switzerland); Institute for Agricultural Sciences, Plant Nutrition, ETH Zurich, Eschikon 33, 8315 Lindau (Switzerland); Schnug, Ewald, E-mail: e.schnug@tu-braunschweig.de [Department of Life Sciences, Technical University of Braunschweig, Pockelsstraße 14, D-38106 Braunschweig (Germany); Prasser, Horst-Michael, E-mail: prasser@lke.mavt.ethz.ch [Institute of Energy Technology, Laboratory of Nuclear Energy Systems, ETH Zurich, Sonneggstrasse 3, 8092 Zurich (Switzerland); Frossard, Emmanuel, E-mail: emmanuel.frossard@usys.ethz.ch [Institute for Agricultural Sciences, Plant Nutrition, ETH Zurich, Eschikon 33, 8315 Lindau (Switzerland)

    2014-04-01

    This study seeks to identify and specify the components that make up the prospects of U recovery from phosphate rock. A systems approach is taken. The assessment includes i) reviewing past recovery experience and lessons learned; ii) identifying factors that determine recovery; and iii) establishing a contemporary evaluation of U endowments in phosphate rock reserves, as well as the available and recoverable amounts from phosphate rock and phosphoric acid production. We find that in the past, recovery did not fulfill its potential and that the breakup of the Soviet Union worsened then-favorable recovery market conditions in the 1990s. We find that an estimated 5.7 million tU may be recoverable from phosphate rock reserves. In 2010, the recoverable tU from phosphate rock and phosphoric acid production may have been 15,000 tU and 11,000 tU, respectively. This could have filled the world U supply-demand gap for nuclear energy production. The results suggest that the U.S., Morocco, Tunisia, and Russia would be particularly well-suited to recover U, taking infrastructural considerations into account. We demonstrate future research needs, as well as sustainability orientations. We conclude that in order to promote investment and production, it seems necessary to establish long-term contracts at guaranteed prices, ensuring profitability for phosphoric acid producers. - Highlights: • We identify components that underlie the recovery of uranium from phosphate rock. • We estimate that 11,000 tU may have been recoverable from phosphoric acid in 2010. • Recovery is a resource conservation and environmental pollution control strategy. • To ensure investment in recovery technology, profitability needs to be secured.

  5. Uranium endowments in phosphate rock

    International Nuclear Information System (INIS)

    Ulrich, Andrea E.; Schnug, Ewald; Prasser, Horst-Michael; Frossard, Emmanuel

    2014-01-01

    This study seeks to identify and specify the components that make up the prospects of U recovery from phosphate rock. A systems approach is taken. The assessment includes i) reviewing past recovery experience and lessons learned; ii) identifying factors that determine recovery; and iii) establishing a contemporary evaluation of U endowments in phosphate rock reserves, as well as the available and recoverable amounts from phosphate rock and phosphoric acid production. We find that in the past, recovery did not fulfill its potential and that the breakup of the Soviet Union worsened then-favorable recovery market conditions in the 1990s. We find that an estimated 5.7 million tU may be recoverable from phosphate rock reserves. In 2010, the recoverable tU from phosphate rock and phosphoric acid production may have been 15,000 tU and 11,000 tU, respectively. This could have filled the world U supply-demand gap for nuclear energy production. The results suggest that the U.S., Morocco, Tunisia, and Russia would be particularly well-suited to recover U, taking infrastructural considerations into account. We demonstrate future research needs, as well as sustainability orientations. We conclude that in order to promote investment and production, it seems necessary to establish long-term contracts at guaranteed prices, ensuring profitability for phosphoric acid producers. - Highlights: • We identify components that underlie the recovery of uranium from phosphate rock. • We estimate that 11,000 tU may have been recoverable from phosphoric acid in 2010. • Recovery is a resource conservation and environmental pollution control strategy. • To ensure investment in recovery technology, profitability needs to be secured

  6. Radiation monitoring network of the Czech Republic

    International Nuclear Information System (INIS)

    Kuca, P.; Novak, L.; Rulik, P.; Tecl, J.

    2003-01-01

    The Radiation Monitoring Network (RMN) of the Czech Republic was established after the Chernobyl accident in 1986 and it is developed all the time. It is co-ordinated by the State Office for Nuclear Safety in co-operation with the National Radiation Protection Institute. Czech RMN consists of the several sub-networks, which include selected or all permanent parts of RMN. The sub-networks are following: the Early Warning Network (EWN), the TLD Territorial Network, the Network of the Measuring Sites of Air Contamination, the Network of Laboratories Equipped with Gamma-spectrometric and Radiochemical Analytical Instrumentation, the Ground and Airborne Mobile Groups. The Laboratory of Monitoring of Internal Contamination and the information system (IS) are a significant part of RMN, too. The data of RMN resulting from monitoring are transferred to the central database of CRMN, processed by the information system (IS). They are used in normal and emergency situations for an evaluation of radiation situation and for preparation of recommendations for protection of the public and the environment. In 2002 any extraordinary radioactivity in the environment was not detected and also none of the measuring points recorded any exceeding of established investigation levels. In components of environment and also in human beings a very low activity of 137 Cs was still measurable, that had been released into environment after the Chernobyl accident and by the nuclear weapon tests in sixties of the last century. (authors)

  7. Geological and rock mechanics aspects of the long-term evolution of a crystalline rock site

    International Nuclear Information System (INIS)

    Cosgrove, J.W.; Hudson, J.A.

    2009-01-01

    We consider the stability of a crystalline rock mass and hence the integrity of a radioactive waste repository contained therein by, firstly, identifying the geological evolution of such a site and, secondly, by assessing the likely rock mechanics consequences of the natural perturbations to the repository. In this way, the potency of an integrated geological-rock mechanics approach is demonstrated. The factors considered are the pre-repository geological evolution, the period of repository excavation, emplacement and closure, and the subsequent degradation and natural geological perturbations introduced by glacial loading. It is found that the additional rock stresses associated with glacial advance and retreat have a first order effect on the stress magnitudes and are likely to cause a radical change in the stress regime. There are many factors involved in the related geosphere stability and so the paper concludes with a systems diagram of the total evolutionary considerations before, during and after repository construction. (authors)

  8. A Rock Mechanics and Coupled Hydro mechanical Analysis of Geological Repository of High Level Nuclear Waste in Fractured Rocks

    International Nuclear Information System (INIS)

    Min, Kibok

    2011-01-01

    This paper introduces a few case studies on fractured hard rock based on geological data from Sweden, Korea is one of a few countries where crystalline rock is the most promising rock formation as a candidate site of geological repository of high level nuclear waste. Despite the progress made in the area of rock mechanics and coupled hydro mechanics, extensive site specific study on multiple candidate sites is essential in order to choose the optimal site. For many countries concerned about the safe isolation of nuclear wastes from the biosphere, disposal in a deep geological formation is considered an attractive option. In geological repository, thermal loading continuously disturbs the repository system in addition to disturbances a recent development in rock mechanics and coupled hydro mechanical study using DFN(Discrete Fracture Network) - DEM(Discrete Element Method) approach mainly applied in hard, crystalline rock containing numerous fracture which are main sources of deformation and groundwater flow

  9. Probes and their application to the study of H.F. plasmoids; Les sondes et leur application dans l'etude des plasmoides H.F

    Energy Technology Data Exchange (ETDEWEB)

    Brunet, A; Geller, R [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    In the first part of this paper, we study the single Langmuir probe and the double-probe method. In the second part, we describe the probe-technique in connection with R.F. plasmoids. (author) [French] Dans la premiere partie de cet article, nous rappelons les principes d'utilisation de la sonde simple de Langmuir ainsi que la methode de la sonde double. La seconde partie est consacree a la pratique des sondes dans l'etude des plasmoides H.F. (auteur)

  10. Hydrological and geochemical investigation on the volcanic rock and gneissic rock area

    Energy Technology Data Exchange (ETDEWEB)

    Koh, Yong Kwon; Jeong, Chan Ho; Ryu, Kun Seok; Kim, Byoung Yeop; Park, Hyung Kun; Yu, Sang Woo; Jang, Hyu Kun; Lee, Suk Chi; Choi, Ki Young; Jeon, Hyu Woong; Kim, Do Hyoung [Daejong University, Daejeon (Korea, Republic of)

    2010-01-15

    The purpose of this study is to supply the basic data and optimum study site among volcanic rock area and gneissic rock area for high-level radioactive waste disposal. For this purpose, geological, hydrogeological and geochemical data from previously published literatures were collected and analyzed. In this study, we selected 36 volcanic rock sites and 26 gneissic sites as the candidate sites for high level radwaste disposal. Finally, for four sites(M-1, M-13, V-1 and V-13 sites) were selected as the study sites. The geochemical characteristics of groundwaters of each study site were statistically analyzed. The nitrate contamination and the sea water mixing will be important factors on the assessment of behaviour of radionuclides under groundwater environment. From the deep geothermal study, alkaline and sodium-bicarbonate chemical environment, and sea water mixing should be considered as the key factors for the deep disposal of high-level radioactive waste

  11. Look! It's Rock'n'roll!

    DEFF Research Database (Denmark)

    Lindelof, Anja

    2007-01-01

    , and dates. Consult your library or click here for more information on citing sources. -------------------------------------------------------------------------------- Anja Mølle Lindelof. (2007). Look! it's rock'n'roll! how television participated in shaping the visual genre conventions of popular music...... to personal names, capitalization, and dates. Consult your library or click here for more information on citing sources. -------------------------------------------------------------------------------- Anja Mølle Lindelof. "Look! It's Rock'n'roll! How television participated in shaping the visual genre....... Pay special attention to personal names, capitalization, and dates. Consult your library or click here for more information on citing sources. -------------------------------------------------------------------------------- TY - JOUR T1 - Look! It's Rock'n'roll! How television participated in shaping...

  12. ROCK GLACIERS IN THE KOLYMA HIGHLAND

    Directory of Open Access Journals (Sweden)

    A. A. Galanin

    2012-01-01

    Full Text Available Based on remote mapping and field studies inGrand Rapids, Tumansky,Hasynsky,Del-Urechen Ridges as well as Dukchinsky and Kilgansky Mountain Massifs there were identified about 1160 landforms which morphologically are similar to the rock glaciers or they develop in close association with them. Besides tongue-shaped cirque rock glaciers originated due to ablation, a large number of lobate-shaped slope-associated rock glaciers were recognized. Significant quantity of such forms are developing within the active neotectonic areas, in zones of seismic-tectonic badland and in association with active earthquakes-controlling faults. Multiplication of regional data on volcanic-ash-chronology, lichenometry, Schmidt Hammer Test, pollen spectra and single radiocarbon data, most of the active rock glaciers were preliminary attributed to the Late Holocene.

  13. The source rock characters of U-rich granite

    Energy Technology Data Exchange (ETDEWEB)

    Mingyue, Feng; Debao, He [CNNC Key Laboratory of Uranium Resources Exploration and Evaluation Technology, Beijing Research Institute of Uranium Geology (China)

    2012-03-15

    This paper discusses the stratum composition, lithological association, uranium content of crust and the activation, migration, concentration of uranium at each tectonic cycle in South China. The authors point out that the source rock of U-rich granite is U-rich continental crust which is rich in Si, Al and K. The lithological association is mainly composed of terrestrial clastic rocks formation of mudstone and sandstone, mingled with intermediate-acidic, mafic pyroclastic rocks and carbonate rocks formation. During tectonic movements, the rocks had undergone regional metamorphism, migmatitization, granitization, and formed U-rich granites finally. (authors)

  14. The source rock characters of U-rich granite

    International Nuclear Information System (INIS)

    Feng Mingyue; He Debao

    2012-01-01

    This paper discusses the stratum composition, lithological association, uranium content of crust and the activation, migration, concentration of uranium at each tectonic cycle in South China. The authors point out that the source rock of U-rich granite is U-rich continental crust which is rich in Si, Al and K. The lithological association is mainly composed of terrestrial clastic rocks formation of mudstone and sandstone, mingled with intermediate-acidic, mafic pyroclastic rocks and carbonate rocks formation. During tectonic movements, the rocks had undergone regional metamorphism, migmatitization, granitization, and formed U-rich granites finally. (authors)

  15. Response of rocks to large stresses

    International Nuclear Information System (INIS)

    Schock, R.N.

    1976-01-01

    To predict the dimensions and characteristics of impact- and explosion-induced craters, one must know the equation of state of the rocks in which the crater is formed. Recent experimental data shed light upon inelastic processes that influence the stress/strain behavior of rocks. We examine these data with a view to developing models that could be used in predicting cratering phenomena. New data is presented on the volume behavior of two dissimilar rocks subjected to tensile stresses

  16. Favorability for uranium in tertiary sedimentary rocks, southwestern Montana

    International Nuclear Information System (INIS)

    Wopat, M.A.; Curry, W.E.; Robins, J.W.; Marjaniemi, D.K.

    1977-10-01

    Tertiary sedimentary rocks in the basins of southwestern Montana were studied to determine their favorability for potential uranium resources. Uranium in the Tertiary sedimentary rocks was probably derived from the Boulder batholith and from silicic volcanic material. The batholith contains numerous uranium occurrences and is the most favorable plutonic source for uranium in the study area. Subjective favorability categories of good, moderate, and poor, based on the number and type of favorable criteria present, were used to classify the rock sequences studied. Rocks judged to have good favorability for uranium deposits are (1) Eocene and Oligocene strata and undifferentiated Tertiary rocks in the western Three Forks basin and (2) Oligocene rocks in the Helena basin. Rocks having moderate favorability consist of (1) Eocene and Oligocene strata in the Jefferson River, Beaverhead River, and lower Ruby River basins, (2) Oligocene rocks in the Townsend and Clarkston basins, (3) Miocene and Pliocene rocks in the Upper Ruby River basin, and (4) all Tertiary sedimentary formations in the eastern Three Forks basin, and in the Grasshopper Creek, Horse Prairie, Medicine Lodge Creek, Big Sheep Creek, Deer Lodge, Big Hole River, and Bull Creek basins. The following have poor favorability: (1) the Beaverhead Conglomerate in the Red Rock and Centennial basins, (2) Eocene and Oligocene rocks in the Upper Ruby River basin, (3) Miocene and Pliocene rocks in the Townsend, Clarkston, Smith River, and Divide Creek basins, (4) Miocene through Pleistocene rocks in the Jefferson River, Beaverhead River, and Lower Ruby River basins, and (5) all Tertiary sedimentary rocks in the Boulder River, Sage Creek, Muddy Creek, Madison River, Flint Creek, Gold Creek, and Bitterroot basins

  17. Footwear in rock climbing: Current practice.

    Science.gov (United States)

    McHenry, R D; Arnold, G P; Wang, W; Abboud, R J

    2015-09-01

    Many rock climbers wear ill-fitting and excessively tight footwear during activity. However, there is insufficient evidence of the extent or harms of this practice. To investigate footwear use in rock climbers with a focus on issues surrounding fit. A cross-sectional study with active rock climbers of over one year of experience completing a survey on their activity and footwear. Additionally, the authors quantified foot and shoe lengths and sizes alongside demographic data. Ill-fitting and excessively tight footwear was found in 55 out of 56 rock climbers. Foot pain during activity was also commonplace in 91% of the climbers. A mean size reduction of almost 4 UK shoe sizes was found between the climbers' street shoe size and that of their climbing footwear using a calibrated foot/shoe ruler. There is an unfortunate association of climbers of higher abilities seeking a tighter shoe fit (pfootwear use amongst rock climbers, further investigation may aim to quantify its impact and seek a solution balancing climbing performance while mitigating foot injury. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. The Rock that Hit New York

    Energy Technology Data Exchange (ETDEWEB)

    Meade, Roger Allen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Keksis, August Lawrence [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-10-03

    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 of 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.

  19. Contribution to the study on the flow rate adjustment for gas cooled power reactors (1964); Contributiom a l'etude de reglage du debit pour les reacteurs industriels refroidis par gaz (1964)

    Energy Technology Data Exchange (ETDEWEB)

    Milliot, B. [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1961-06-15

    1. This original study firstly defines the problem of the adjustment of the coolant flow rate in a reactor channel as a function of the corresponding heat transfer equations and of the local and temporal neutron flux. The necessity of such an adjustment is pointed out and the modifying parameters are studied. An adjustment study using the envelope of the possible flux curves is developed. A short study on the technology and the economical advantage of this adjustment is presented. Some measurements, made on G-1 and G-2, show the precision one can obtain from adjustment apparatus itself as well as from the complete reactor adjustment system. 2. Evolution of nuclear properties of fuel in an heterogeneous thermal reactor. In the first port of this paper, the phenomena of fuel evolution have been mainly pointed out. Now a bibliographical study more qualitatively than quantitatively has been done. This survey specifies the present theories and relates to a real effective cross section and also yields to the bases of such a nuclear calculation. (author) [French] 1. Cette etude originale definit d'abord le probleme du reglage du debit de refrigerant dans un canal de reacteur en fonction de la formulation du calcul des performances thermodynamiques de ce canal et des variations du flux neutronique dans l'espace et le temps. La necessite du reglage est ensuite mise en evidence et les parametres le modifiant sont etudies. Une methode de reglage, basee sur l'emploi d 'une courbe enveloppe des courbes de flux possibles, est donnee. Une breve etude de la technologie et des incidences economiques du reglage est presentee. Des mesures effectuees sur les reacteurs G-1 et G-2 montrent la precision que l'on peut attendre des dispositifs de reglage comme du reglage d'ensemble du reacteur lui-meme. 2. Evolution des proprietes nucleaires du combustible dans un reacteur heterogene a neutrons thermiques. Les phenomenes d'evolution du combustible

  20. Failure Mechanisms of Brittle Rocks under Uniaxial Compression

    Science.gov (United States)

    Liu, Taoying; Cao, Ping

    2017-09-01

    The behaviour of a rock mass is determined not only by the properties of the rock matrix, but mostly by the presence and properties of discontinuities or fractures within the mass. The compression test on rock-like specimens with two prefabricated transfixion fissures, made by pulling out the embedded metal inserts in the pre-cured period was carried out on the servo control uniaxial loading tester. The influence of the geometry of pre-existing cracks on the cracking processes was analysed with reference to the experimental observation of crack initiation and propagation from pre-existing flaws. Based on the rock fracture mechanics and the stress-strain curves, the evolution failure mechanism of the fissure body was also analyzed on the basis of exploring the law of the compression-shear crack initiation, wing crack growth and rock bridge connection. Meanwhile, damage fracture mechanical models of a compression-shear rock mass are established when the rock bridge axial transfixion failure, tension-shear combined failure, or wing crack shear connection failure occurs on the specimen under axial compression. This research was of significance in studying the failure mechanism of fractured rock mass.

  1. Permeability Evolution and Rock Brittle Failure

    OpenAIRE

    Sun Qiang; Xue Lei; Zhu Shuyun

    2015-01-01

    This paper reports an experimental study of the evolution of permeability during rock brittle failure and a theoretical analysis of rock critical stress level. It is assumed that the rock is a strain-softening medium whose strength can be described by Weibull’s distribution. Based on the two-dimensional renormalization group theory, it is found that the stress level λ c (the ratio of the stress at the critical point to the peak stress) depends mainly on the homogeneity index or shape paramete...

  2. Developing a Virtual Rock Deformation Laboratory

    Science.gov (United States)

    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. Study on Excitation-triggered Damage Mechanism in Perilous Rock

    Science.gov (United States)

    Chen, Hongkai; Wang, Shengjuan

    2017-12-01

    Chain collapse is easy to happen for perilous rock aggregate locating on steep high slope, and one of the key scientific problems is the damage mechanism of perilous rock under excitation action at perilous rock rupture. This paper studies excitation-triggered damage mechanism in perilous rock by wave mechanics, which gives three conclusions. Firstly, when only the normal incidence attenuation spread of excitation wave is considered, while the energy loss is ignored for excitation wave to spread in perilous rock aggregate, the paper establishes one method to calculate peak velocity when excitation wave passes through boundary between any two perilous rock blocks in perilous rock aggregate. Secondly, following by Sweden and Canmet criteria, the paper provides one wave velocity criterion for excitation-triggered damage in the aggregate. Thirdly, assuming double parameters of volume strain of cracks or fissures in rock meet the Weibull distribution, one method to estimate micro-fissure in excitation-triggered damage zone in perilous rock aggregate is established. The studies solve the mechanical description problem for excitation-triggered damage in perilous rock, which is valuable in studies on profoundly rupture mechanism.

  4. Uranium deposits in granitic rocks

    International Nuclear Information System (INIS)

    Nishimori, R.K.; Ragland, P.C.; Rogers, J.J.W.; Greenberg, J.K.

    1977-01-01

    This report is a review of published data bearing on the geology and origin of uranium deposits in granitic, pegmatitic and migmatitic rocks with the aim of assisting in the development of predictive criteria for the search for similar deposits in the U.S. Efforts were concentrated on the so-called ''porphyry'' uranium deposits. Two types of uranium deposits are primarily considered: deposits in pegmatites and alaskites in gneiss terrains, and disseminations of uranium in high-level granites. In Chapter 1 of this report, the general data on the distribution of uranium in igneous and metamorphic rocks are reviewed. Chapter 2 contains some comments on the classification of uranium deposits associated with igneous rocks and a summary of the main features of the geology of uranium deposits in granites. General concepts of the behavior of uranium in granites during crustal evolution are reviewed in Chapter 3. Also included is a discussion of the relationship of uranium mineralization in granites to the general evolution of mobile belts, plus the influence of magmatic and post-magmatic processes on the distribution of uranium in igneous rocks and related ore deposits. Chapter 4 relates the results of experimental studies on the crystallization of granites to some of the geologic features of uranium deposits in pegmatites and alaskites in high-grade metamorphic terrains. Potential or favorable areas for igneous uranium deposits in the U.S.A. are delineated in Chapter 5. Data on the geology of specific uranium deposits in granitic rocks are contained in Appendix 1. A compilation of igneous rock formations containing greater than 10 ppM uranium is included in Appendix 2. Appendix 3 is a report on the results of a visit to the Roessing area. Appendix 4 is a report on a field excursion to eastern Canada

  5. Rock Art in Kurdistan Iran

    Directory of Open Access Journals (Sweden)

    Jamal Lahafian

    2013-12-01

    Full Text Available Kurdistan, with great potential and prehistoric resources, has numerous petroglyphs in different areas of the province. During the last 14 years of extensive field study, more than 30 sites of rock art have been identified and introduced by the author. In this article, we summarize these rock art areas in Iranian Kurdistan.

  6. Aqueous Alteration of Endeavour Crater Rim Apron Rocks

    Science.gov (United States)

    Ming, D. W.; Mittlefehldt, D. W.; Gellert, R.; Clark, B. C.; Morris, R. V.; Yen, A. S.; Arvidson, R. E.; Crumpler, L. S.; Farrand, W. H.; Grant, J. A., III; Jolliff, B. L.; Parker, T. J.; Peretyazhko, T.

    2014-12-01

    Mars Exploration Rover Opportunity is exploring Noachian age rocks of the rim of 22 km diameter Endeavour crater. Overlying the pre-impact lithologies and rim breccias is a thin apron of fine-grained sediments, the Grasberg fm, forming annuli on the lower slopes of rim segments. Hesperian Burns fm sandstones overly the Grasberg fm. Grasberg rocks have major element compositions that are distinct from Burns fm sandstones, especially when comparing interior compositions exposed by the Rock Abrasion Tool. Grasberg rocks are also different from Endeavour rim breccias, but have general compositional similarities to them. Grasberg sediments are plausibly fine-grained materials derived from the impact breccias. Veins of CaSO4 transect Grasberg fm rocks demonstrating post-formation aqueous alteration. Minor/trace elements show variations consistent with mobilization by aqueous fluids. Grasberg fm rocks have low Mn and high Fe/Mn ratios compared to the other lithologies. Manganese likely was mobilized and removed from the Grasberg host rock by redox reactions. We posit that Fe2+ from acidic solutions associated with formation of the Burns sulfate-rich sandstones acted as an electron donor to reduce more oxidized Mn to Mn2+. The Fe contents of Grasberg rocks are slightly higher than in other rocks suggesting precipitation of Fe phases in Grasberg materials. Pancam spectra show that Grasberg rocks have a higher fraction of ferric oxide minerals than other Endeavour rim rocks. Solutions transported Mn2+ into the Endeavour rim materials and oxidized and/or precipitated it in them. Grasberg has higher contents of the mobile elements K, Zn, Cl, and Br compared to the rim materials. Similar enrichments of mobile elements were measured by the Spirit APXS on West Spur and around Home Plate in Gusev crater. Enhancements in these elements are attributed to interactions of hydrothermal acidic fluids with the host rocks. Interactions of fluids with the Grasberg fm postdate the genesis

  7. Radiation monitoring network of the Czech Republic

    International Nuclear Information System (INIS)

    Drabova, D.; Prouza, Z.; Malatova, I.; Bucina, I.

    1996-01-01

    Radiation Monitoring Network of the Czech Republic (RMN) was established after the Chernobyl accident. It consists of technical centers, laboratories and monitoring groups of State Office for Nuclear Safety, National Radiation Protection Institute, nuclear power plants, hydrometeorological service, army and Civil Defense, research institutes and other institutions. The structure of RMN, its basic components and responsible institutions are described. (author)

  8. An unconventional depiction of viewpoint in rock art.

    Science.gov (United States)

    Pettigrew, Jack; Scott-Virtue, Lee

    2015-01-01

    Rock art in Africa sometimes takes advantage of three-dimensional features of the rock wall, such as fissures or protuberances, that can be incorporated into the artistic composition (Lewis-Williams, 2002). More commonly, rock artists choose uniform walls on which two-dimensional depictions may represent three-dimensional figures or objects. In this report we present such a two-dimensional depiction in rock art that we think reveals an intention by the artist to represent an unusual three-dimensional viewpoint, namely, with the two human figures facing into the rock wall, instead of the accustomed Western viewpoint facing out!

  9. Assessment of abrasiveness for research of rock cutting

    Directory of Open Access Journals (Sweden)

    Milan Labaš

    2012-12-01

    Full Text Available Rock abrasiveness is ability of rock to wear down the working tool during the mutual interaction between the working indentorand the rock in the mechanical rock cutting process. The cutting indentor is worn down during the interaction, which changes itsgeometric dimensions causing the enlargement of a contact area between the tool and the rock surface. The changes in these dimensionsconsequently alter the rate of advance of the drilling machine and the specific cutting energy. We have determined the abrasivenessaccording to the norm ON 44 1121 (1982 on the testing device constructed at the Institute of Geotechnics SAS.

  10. Intellektuaalne rock

    Index Scriptorium Estoniae

    2007-01-01

    Briti laulja-helilooja ja näitleja Toyah Willcox ning Bill Rieflin ansamblist R.E.M. ja Pat Mastelotto King Krimsonist esinevad koos ansamblitega The Humans ja Tuner 25. okt. Tallinnas Rock Cafés ja 27. okt Tartu Jaani kirikus

  11. GRAPHITIZATION OF METASEDIMENTARY ROCKS IN THE WESTERN KONYA

    Directory of Open Access Journals (Sweden)

    Hüseyin KURT

    2000-01-01

    Full Text Available The Paleozoic-Mesozoic metasedimentary rocks in the study area are metacarbonate, metachert, metapelite, metasandstone and metaconglomerate. Graphite layers are 1cm to 2m thick, extend laterally for tens of meters and are intercalated with metasedimentary rocks. Generally, the graphite is black in color, with a well developed cleavage which is concordant with the cleavage of the host rocks. In addition, the crystal and flake graphites formed in metasedimentary rocks are mostly aligned parallel to the cleavage planes. These metamorphic rocks are subjected to shearing and granulation providing structural control for the development of graphite. It was probably this phenomenon that first led to emphasize the relationship between graphite and metasedimentary rocks. Graphite mineralization has been controlled by bedding, microfractures and granulations. Briefly, the metamorphism has converted carbonaceous matter into graphite .

  12. Ramsey numbers and adiabatic quantum computing.

    Science.gov (United States)

    Gaitan, Frank; Clark, Lane

    2012-01-06

    The graph-theoretic Ramsey numbers are notoriously difficult to calculate. In fact, for the two-color Ramsey numbers R(m,n) with m, n≥3, only nine are currently known. We present a quantum algorithm for the computation of the Ramsey numbers R(m,n). We show how the computation of R(m,n) can be mapped to a combinatorial optimization problem whose solution can be found using adiabatic quantum evolution. We numerically simulate this adiabatic quantum algorithm and show that it correctly determines the Ramsey numbers R(3,3) and R(2,s) for 5≤s≤7. We then discuss the algorithm's experimental implementation, and close by showing that Ramsey number computation belongs to the quantum complexity class quantum Merlin Arthur.

  13. Thermal expansion of granite rocks

    International Nuclear Information System (INIS)

    Stephansson, O.

    1978-04-01

    The thermal expansion of rocks is strongly controlled by the thermal expansion of the minerals. The theoretical thermal expansion of the Stripa Granite is gound to be 21 . 10 -6 [deg C] -1 at 25 deg C and 38 . 10 -6 [deg C] -1 at 400 deg C. The difference in expansion for the rock forming minerals causes micro cracking at heating. The expansion due to micro cracks is found to be of the same order as the mineral expansion. Most of the micro cracks will close at pressures of the order of 10 - 20 MPa. The thermal expansion of a rock mass including the effect of joints is determined in the pilot heater test in the Stripa Mine

  14. Hopi and Anasazi Alignments and Rock Art

    Science.gov (United States)

    Bates, Bryan C.

    The interaction of light and shadow on ancestral Puebloan rock art, or rock art demarcating sunrise/set horizon points that align with culturally significant dates, has long been assumed to be evidence of "intentional construct" for marking time or event by the native creator. However, anthropological rock art research requires the scientific control of cultural time, element orientation and placement, structure, and association with other rock art elements. The evaluation of five exemplars challenges the oft-held assumption that "if the interaction occurs, it therefore supports intentional construct" and thereby conveys meaning to the native culture.

  15. Comparison of laboratory, in situ, and rock mass measurements of the hydraulic conductivity of metamorphic rock at the Savannah River Plant near Aiken, South Carolina

    International Nuclear Information System (INIS)

    Marine, I.W.

    1980-01-01

    In situ testing of exploratory wells in metamorphic rock indicates that two types of fracturing occur in the rock mass. Rock containing small openings that permit only extremely slow movement of water is termed virtually impermeable rock. Rock containing openings of sufficient size to permit transmission of water at a significantly faster rate is termed hydraulically transmissive rock. Laboratory methods are unsuitable for measuring hydraulic conductivity in hydraulically transmissive rock; however, for the virtually impermeable rock, values comparable to the in situ tests are obtained. The hydraulic conductivity of the rock mass over a large region is calculated by using the hydraulic gradient, porosity, and regional velocity. This velocity is determined by dividing the inferred travel distance by the age of water which is determined by the helium content of the water. This rock mass hydraulic conductivity value is between the values measured for the two types of fractures, but is closer to the measured value for the virtually impermeable rock. This relationship is attributed to the control of the regional flow rate by the virtually impermeable rock where the discrete fractures do not form a continuous open connection through the entire rock mass. Thus, laboratory methods of measuring permeability in metamorphic rock are of value if they are properly applied

  16. The global rock art database: developing a rock art reference model for the RADB system using the CIDOC CRM and Australian heritage examples

    Science.gov (United States)

    Haubt, R. A.

    2015-08-01

    The Rock Art Database (RADB) is a virtual organisation that aims to build a global rock art community. It brings together rock art enthusiasts and professionals from around the world in one centralized location through the deployed publicly available RADB Management System. This online platform allows users to share, manage and discuss rock art information and offers a new look at rock art data through the use of new technologies in rich media formats. Full access to the growing platform is currently only available for a selected group of users but it already links over 200 rock art projects around the globe. This paper forms a part of the larger Rock Art Database (RADB) project. It discusses the design stage of the RADB System and the development of a conceptual RADB Reference Model (RARM) that is used to inform the design of the Rock Art Database Management System. It examines the success and failure of international and national systems and uses the Australian heritage sector and Australian rock art as a test model to develop a method for the RADB System design. The system aims to help improve rock art management by introducing the CIDOC CRM in conjunction with a rock art specific domain model. It seeks to improve data compatibility and data sharing to help with the integration of a variety of resources to create the global Rock Art Database Management System.

  17. Experimental study of the radio-active contamination of certain cultivated plants by irrigation water; Etude experimentale de la contamination radioactive par l'eau d'irrigation de certaines plantes cultivees

    Energy Technology Data Exchange (ETDEWEB)

    Michon, G. [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires; Barbier, G.; Le Blaye, P.; Brossard, M. [Station Centrale d' Agronomie, 78 - Versailles (France); Fioramonti, S.; Marty, J.R. [Station Agronomique de Toulouse, 31 (France); Benard, P.; Flanzy, M. [Station Centrale de Technologie des Produits Vegetaux, 11 - Narbonne (France); Delas, J.; Delmas, J.; Demias, Ch. [Station d' Agronomie de Bordeaux (Pont de la Maye), 33 (France); Huguet, C. [Station Agronomique d' Avignon, 84 (France)

    1964-07-01

    This report follows on to the CEA reports no 1860 and 2159 and gives the results obtained during the years 1961 and 1962. These results confirm for the most part those obtained previously and deal also with a larger variety of vegetables. Vines and artificial prairies were also dealt with during the course of this work. The large dispersion of the limiting values of the coefficient r (the ratio between the amount of radio-elements in a kilogram of product harvested, to the amount of radio-elements present in a litre of irrigation water) with different types of soil, different plant types, etc... , makes it impossible to draw any general conclusions. Each case of rejection requires a special study of which the outlive is given. At all events it is to be expected that in the majority of cases these studies will lead to a decrease in the norms now in force. (authors) [French] Ce rapport fait suite aux rapports CEA no 1860 et 2159 et rapporte les resultats obtenus pendant les annees 1961 et 1962. Ces resultats confirment dans l'ensemble ceux precedemment obtenus tout en augmentant la variete des legumes etudies. La vigne et les prairies artificielles ont egalement fait l'objet d'etudes. La grande dispersion des valeurs limites du coefficient r (rapport entre la quantite de radioelements dans un kg de produits recoltes a la quantite de radioelements presente dans un litre d'eau d'irrigation) en rapport avec la nature des sols, le type vegetal, etc.., ne permet pas de degager de conclusions generales. Chaque cas de rejet necessite une etude particuliere dont le schema est donne. En tout etat de cause l'on doit s'attendre a ce que dans la plupart des cas ces etudes conduisent a une diminution des normes actuellement utilisees. (auteurs)

  18. Studies of elements used in hertzian interferometry (millimetric waves). Measurement of the permittivity of a liquid dielectric; Etudes d'elements utilises en interferometrie hertzienne (ondes millimetriques). Mesure de la permittivite de dielectrique liquide

    Energy Technology Data Exchange (ETDEWEB)

    Dagai, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-12-01

    Study of some elements used in EHF interferometry (bond of millimeter waves). This study is about design of the following elements: horns, horns associated with lens, power separators: -) Study of assemblies allowing measurements of complex dielectric constants of liquids. These devices are used in free propagation about wave lengths {<=} 2 mm; -) Studied devices: Interferometer for 2 separated waves and Michelson's type interferometer; -) 4 liquids have been used: {epsilon}'{sub r} Octane from -50 to 70 C (-58 to 158 F), {epsilon}'{sub r} and {epsilon}'' [Monochlorobenzene at 22,8 C (73 F), Mixture of octane with 10,8 per cent citral at 22 C (72 F) and Benzene at 21 C (70 F)]. -) Precision obtained about measurements: {delta}{epsilon}'/{epsilon}' de 1 a 2%, {delta}{epsilon}''/{epsilon}'' de 4 a 6%.(author) [French] Etudes d'elements utilises en interferometrie hertzienne fonctionnant en ondes millimetriques. Cette etude porte sur la realisation des elements suivants: cornets, cornets associes aux lentilles, separateurs de puissance. Etudes des montages permettant les mesures de la constante dielectrique complexe des corps liquides. Ces montages fonctionnent en propagation libre, sur des longueurs d'onde inferieures ou egales a 2 millimetres. Les montages etudies sont: interferometre a deux ondes separees et interferometre du type Michelson. De plus 4 liquides ont ete etudies: {epsilon}'{sub r} octane de -50 a 70 C, {epsilon}'{sub r} et {epsilon}'' [monochlorobenzene a 22,8 C et melange octane avec 10,8 pour cent citral a 22 C, Benzene a 21 C]. Les precisions obtenues sur les mesures sont: {delta}{epsilon}'/{epsilon}' de 1 a 2 pour cent, {delta}{epsilon}''/{epsilon}'' de 4 a 6 pour cent.

  19. Prediction of Fracture Behavior in Rock and Rock-like Materials Using Discrete Element Models

    Science.gov (United States)

    Katsaga, T.; Young, P.

    2009-05-01

    The study of fracture initiation and propagation in heterogeneous materials such as rock and rock-like materials are of principal interest in the field of rock mechanics and rock engineering. It is crucial to study and investigate failure prediction and safety measures in civil and mining structures. Our work offers a practical approach to predict fracture behaviour using discrete element models. In this approach, the microstructures of materials are presented through the combination of clusters of bonded particles with different inter-cluster particle and bond properties, and intra-cluster bond properties. The geometry of clusters is transferred from information available from thin sections, computed tomography (CT) images and other visual presentation of the modeled material using customized AutoCAD built-in dialog- based Visual Basic Application. Exact microstructures of the tested sample, including fractures, faults, inclusions and void spaces can be duplicated in the discrete element models. Although the microstructural fabrics of rocks and rock-like structures may have different scale, fracture formation and propagation through these materials are alike and will follow similar mechanics. Synthetic material provides an excellent condition for validating the modelling approaches, as fracture behaviours are known with the well-defined composite's properties. Calibration of the macro-properties of matrix material and inclusions (aggregates), were followed with the overall mechanical material responses calibration by adjusting the interfacial properties. The discrete element model predicted similar fracture propagation features and path as that of the real sample material. The path of the fractures and matrix-inclusion interaction was compared using computed tomography images. Initiation and fracture formation in the model and real material were compared using Acoustic Emission data. Analysing the temporal and spatial evolution of AE events, collected during the

  20. Geotechnical properties of rock

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, R.; Gorski, B.; Gyenge, M.

    1995-12-31

    The manual is a compilation of the geotechnical properties of many types of rock that are typical of Canadian mining environments. Included are values for density, porosity, compressive and shear wave velocity, uniaxial compressive strength, Young`s modulus, and Poisson`s ratio. The data base contains material constants that were determined using the Hoek and Brown failure criteria for both before and after failure conditions. 76 data sheets of rock properties in Canadian mines are included. 7 refs., 85 figs., 3 tabs.

  1. Relating rock avalanche morphology to emplacement processes

    Science.gov (United States)

    Dufresne, Anja; Prager, Christoph; Bösmeier, Annette

    2015-04-01

    The morphology, structure and sedimentological characteristics of rock avalanche deposits reflect both internal emplacement processes and external influences, such as runout path characteristics. The latter is mainly predisposed by topography, substrate types, and hydrogeological conditions. Additionally, the geological setting at the source slope controls, e.g. the spatial distribution of accumulated lithologies and hence material property-related changes in morphology, or the maximum clast size and amount of fines of different lithological units. The Holocene Tschirgant rock avalanche (Tyrol, Austria) resulted from failure of an intensely deformed carbonate rock mass on the southeast face of a 2,370-m-high mountain ridge. The initially sliding rock mass rapidly fragmented as it moved towards the floor of the Inn River valley. Part of the 200-250 x 106 m3 (Patzelt 2012) rock avalanche debris collided with and moved around an opposing bedrock ridge and flowed into the Ötz valley, reaching up to 6.3 km from source. Where the Tschirgant rock avalanche spread freely it formed longitudinal ridges aligned along motion direction as well as smaller hummocks. Encountering high topography, it left runup ridges, fallback patterns (i.e. secondary collapse), and compressional morphology (successively elevated, transverse ridges). Further evidence for the mechanical landslide behaviour is given by large volumes of mobilized valley-fill sediments (polymict gravels and sands). These sediments indicate both shearing and compressional faulting within the rock avalanche mass (forming their own morphological units through, e.g. in situ bulldozing or as distinctly different hummocky terrain), but also indicate extension of the spreading landslide mass (i.e. intercalated/injected gravels encountered mainly in morphological depressions between hummocks). Further influences on its morphology are given by the different lithological units. E.g. the transition from massive dolomite

  2. Research of compression strength of fissured rock mass

    Directory of Open Access Journals (Sweden)

    А. Г. Протосеня

    2017-03-01

    Full Text Available The article examines a method of forecasting strength properties and their scale effect in fissured rock mass using computational modelling with final elements method in ABAQUS software. It shows advantages of this approach for solving tasks of determining mechanical properties of fissured rock mass, main stages of creating computational geomechanic model of rock mass and conducting a numerical experiment. The article presents connections between deformation during loading of numerical model, inclination angle of main fracture system from uniaxial and biaxial compression strength value, size of the sample of fissured rock mass and biaxial compression strength value under conditions of apatite-nepheline rock deposit at Plateau Rasvumchorr OAO «Apatit» in Kirovsky region of Murmanskaya oblast. We have conducted computational modelling of rock mass blocks testing in discontinuities based on real experiment using non-linear shear strength criterion of Barton – Bandis and compared results of computational experiments with data from field studies and laboratory tests. The calculation results have a high-quality match to laboratory results when testing fissured rock mass samples.

  3. Contribution to the study of the {sup 31}P, {sup 1}H spin spin coupling constant N. M. R. in three co-ordinated phosphorus compounds. Influence of the bond orientation and of the nature of the substituent around the phosphorus atom; Contribution a l'etude des constantes de couplage {sup 31}P, {sup 1}H en R.M.N. dans les composes organo-phosphores tricoordines. Influence des facteurs geometriques et de la nature des substituants au niveau du phosphore

    Energy Technology Data Exchange (ETDEWEB)

    Robert, J B [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1969-07-01

    In order to investigate the influence of the configuration at the phosphorus atom and the influence of the substituents attached to the phosphorus atom on the J{sub PH} spin spin coupling constant, we have performed the NMR spectrum analysis of some three coordinated organo-phosphorus compounds. The studied coupling constants are {sup 3}J{sub PH} through P-O-C-H and P-C-C-H fragments and {sup 2}J{sub PH} through P-C-H fragment. The results clearly show that on the NMR time scale, in all the studied compounds (1,3,2-dioxaphospholanes, 1,3,2-dioxaphosphorinanes, 3-phospha-cyclopentene and 4-phosphorinanone) there is no inversion of the bonds around phosphorous. This conclusion held also for secondary phosphines. For a given geometry of the bonds joining the P and H atoms, and a given disposition of the bonds around the phosphorus atom, there is only a little influence of the nature of the substituents on the J{sub PH} spin coupling constants. The geometrical dependence of the {sup 3}J{sub PH} cannot be explained by a 'Karplus law'. There is an influence of the bond disposition around phosphorus. In the case of the {sup 2}J{sub P-C-H}, one can plot a curve {sup 2}J{sub P-C-H} = f({alpha}) (0{<=} {alpha} {<=} 180), {alpha} denote the dihedral angle of the two plane defined the first one by the P, C and H atoms, and the second one by the P-C bond together with the three-fold axis of the bond around phosphorus assuming a regular pyramidal arrangement. The function {sup 2}J{sub P-C-H} = f({alpha}) has two maxima, one for {alpha} = 0 degrees and the other for {alpha} = 180 degrees, and also a minimum for {alpha} = 110 degrees. (author) [French] Ce travail consiste en l'analyse par resonance magnetique nucleaire des constantes de couplage phosphore-proton dans des derives organo-phosphores tricoordines dans un double but: examen de la stabilite des liaisons au niveau du phosphore et etude de l'influence de la disposition des liaisons et de la nature de substituants au

  4. Excange interactions and induced Eu3+ magnetic order in RMnO3 investigated using resonant X-ray diffraction

    International Nuclear Information System (INIS)

    Skaugen, Arvid

    2015-03-01

    The so-called multiferroics, materials that concomitantly exhibit more than one ferroic order, have in recent years attracted much attention owing to their possible applications in high density data storage, high sensitivity ac magnetic field sensors and novel spintronic devices. In particular, multiferroics with strong magnetoelectric coupling are more attractive. Among such multiferroics, an interesting special class is the orthorhombic manganites with perovskite structure. In these compounds, frustration serves to destabilize ordinary ferromagnetic or antiferromagnetic ordering, giving rise to rich phase diagrams due to several competing magnetic interactions. Interactions between strong rare earth magnetic moments and weaker transition metal moments add another level of complexity, as well as interest. The current dissertation presents results obtained investigating the magnetic structure responsible for ferroelectricity in a few selected multiferroic compounds, using x-ray resonant magnetic scattering (XRMS). In particular, single crystals of Eu 1-x Y x MnO 3 have been studied at low temperatures and in high magnetic fields. This series of compounds is similar in structure to the heavily studied RMnO 3 (R=Tb,Gd,Dy), only without rare earth magnetism. The novel technique of full polarization analysis has been used to determine the complicated cycloidal Mn magnetic ordering, and additional components due to the Dzyaloshinskii-Moriya interactions have been identified. In the compound Eu 0.8 Y 0.2 MnO 3 , two coexisting multiferroic phases were observed, and a magnetoelectric coupling between the two was established. Moreover, magnetic order of the formally non-magnetic rare earth ion Eu 3+ was observed in the same compound. It has been concluded to result from a Van Vleck type excitation of the J = 0 ground state due to the symmetry-breaking internal exchange field from the Mn magnetic moments. In addition, this dissertation reports on high field investigations

  5. K-U-Th systematics of terrestrial igneous rocks for planetological comparisons: volcanic rocks of the Earth oceanic island arc and Venus surface material

    International Nuclear Information System (INIS)

    Nikolaeva, O.V.

    1997-01-01

    Principles of the formation o data base for 339 samples of oceanic island arc (OIA) igneous rocks of the Earth available in literature are described as well as of the formation of fresh rock sample, characteristics of this sample, and K-U-Th-systematics of the fresh igneous rocks of Earth OIA. Results of comparison of the Venus measured rocks and Earth OIA rocks by K, U, Th

  6. Digital Rock Studies of Tight Porous Media

    Energy Technology Data Exchange (ETDEWEB)

    Silin, Dmitriy [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2012-08-07

    This technical report summarizes some recently developed approaches to studies of rock properties at a pore scale. Digital rock approach is complementary to laboratory and field studies. It can be especially helpful in situations where experimental data are uncertain, or are difficult or impossible to obtain. Digitized binary images of the pore geometries of natural rocks obtained by different imaging techniques are the input data. Computer-generated models of natural rocks can be used instead of images in a case where microtomography data are unavailable, or the resolution of the tools is insufficient to adequately characterize the features of interest. Simulations of creeping viscous flow in pores produce estimates of Darcy permeability. Maximal Inscribed Spheres calculations estimate two-phase fluid distribution in capillary equilibrium. A combination of both produce relative permeability curves. Computer-generated rock models were employed to study two-phase properties of fractured rocks, or tight sands with slit-like pores, too narrow to be characterized with micro-tomography. Various scenarios can simulate different fluid displacement mechanisms, from piston-like drainage to liquid dropout at the dew point. A finite differences discretization of Stokes equation is developed to simulate flow in the pore space of natural rocks. The numerical schemes are capable to handle both no-slip and slippage flows. An upscaling procedure estimates the permeability by subsampling a large data set. Capillary equilibrium and capillary pressure curves are efficiently estimated with the method of maximal inscribed spheres both an arbitrary contact angle. The algorithms can handle gigobytes of data on a desktop workstation. Customized QuickHull algorithms model natural rocks. Capillary pressure curves evaluated from computer-generated images mimic those obtained for microtomography data.

  7. Lead isotopes in archaean plutonic rocks

    International Nuclear Information System (INIS)

    Oversby, V.M.

    1978-01-01

    Archaean intrusive rocks have initial Pb isotopic compositions which show a varied and complex history for the source regions of the rocks. Even the oldest rocks from Greenland indicate heterogenous U and Pb distribution prior to 3800 m.y. ago. Source regions with μ values less than 7 must have played a significant role in the early history of the earth. By late Archaean time U/Pb ratios of source regions had increased substantially. Data from Australia and North America show distinct regional differences, both within and between continents. (Auth.)

  8. Laboratory measurements of rock thermal properties

    DEFF Research Database (Denmark)

    Bording, Thue Sylvester; Balling, N.; Nielsen, S.B.

    The thermal properties of rocks are key elements in understanding and modelling the temperature field of the subsurface. Thermal conductivity and thermal diffusivity can be measured in the laboratory if rock samples can be provided. We have introduced improvements to the divided bar and needle...... probe methods to be able to measure both thermal conductivity and thermal diffusivity. The improvements we implement include, for both methods, a combination of fast numerical finite element forward modelling and a Markov Chain Monte Carlo inversion scheme for estimating rock thermal parameters...

  9. Advances and Applications of Rock Physics for Hydrocarbon Exploration

    Directory of Open Access Journals (Sweden)

    Valle-Molina C.

    2012-10-01

    Full Text Available Integration of the geological and geophysical information with different scale and features is the key point to establish relationships between petrophysical and elastic characteristics of the rocks in the reservoir. It is very important to present the fundamentals and current methodologies of the rock physics analyses applied to hydrocarbons exploration among engineers and Mexican students. This work represents an effort to capacitate personnel of oil exploration through the revision of the subjects of rock physics. The main aim is to show updated improvements and applications of rock physics into seismology for exploration. Most of the methodologies presented in this document are related to the study the physical and geological mechanisms that impact on the elastic properties of the rock reservoirs based on rock specimens characterization and geophysical borehole information. Predictions of the rock properties (litology, porosity, fluid in the voids can be performed using 3D seismic data that shall be properly calibrated with experimental measurements in rock cores and seismic well log data

  10. Rockin' around the Rock Cycle

    Science.gov (United States)

    Frack, Susan; Blanchard, Scott Alan

    2005-01-01

    In this activity students will simulate how sedimentary rocks can be changed into metamorphic rocks by intense pressure. The materials needed are two small pieces of white bread, one piece of wheat bread, and one piece of a dark bread (such as pumpernickel or dark rye) per student, two pieces of waxed paper, scissors, a ruler, and heavy books.…

  11. Smart Rocking Armour Units

    OpenAIRE

    Hofland, B.; Arefin, Syed Shamsil; van der Lem, Cock; van gent, Marcel

    2018-01-01

    This paper describes a method to measure the rocking motion of lab-scale armour units. Sensors as found in mobile phones are used. These sensors, data-storage and battery are all embedded in the model units, such that they can be applied without wires attached to them. The technique is applied to double-layer units in order to compare the results to the existing knowledge for this type of armour layers. In contrast to previous research, the gyroscope reading is used to determine the (rocking)...

  12. Rock Hellsinki, Marketing Research

    OpenAIRE

    Todd, Roosa; Jalkanen, Katariina

    2013-01-01

    This paper is a qualitative research about rock and heavy metal music tourism in the capital city of Finland, Helsinki. As Helsinki can be considered the city of contrasts, the silent nature city mixed with urban activities, it is important to also use the potential of the loud rock and heavy metal music contrasting the silence. Finland is known abroad for bands such as HIM, Nightwish, Korpiklaani and Children of Bodom so it would make sense to utilize these in the tourism sector as well. The...

  13. Rock Burst Mechanics: Insight from Physical and Mathematical Modelling

    Directory of Open Access Journals (Sweden)

    J. Vacek

    2008-01-01

    Full Text Available Rock burst processes in mines are studied by many groups active in the field of geomechanics. Physical and mathematical modelling can be used to better understand the phenomena and mechanisms involved in the bursts. In the present paper we describe both physical and mathematical models of a rock burst occurring in a gallery of a coal mine.For rock bursts (also called bumps to occur, the rock has to possess certain particular rock burst properties leading to accumulation of energy and the potential to release this energy. Such materials may be brittle, or the rock burst may arise at the interfacial zones of two parts of the rock, which have principally different material properties (e.g. in the Poíbram uranium mines.The solution is based on experimental and mathematical modelling. These two methods have to allow the problem to be studied on the basis of three presumptions:· the solution must be time dependent,· the solution must allow the creation of cracks in the rock mass,· the solution must allow an extrusion of rock into an open space (bump effect. 

  14. Range and intensity vision for rock-scene segmentation

    CSIR Research Space (South Africa)

    Mkwelo, SG

    2007-11-01

    Full Text Available This paper presents another approach to segmenting a scene of rocks on a conveyor belt for the purposes of measuring rock size. Rock size estimation instruments are used to monitor, optimize and control milling and crushing in the mining industry...

  15. Some clastic rocks as parent rocks in beech forests of Brezovica - Južni Kučaj

    Directory of Open Access Journals (Sweden)

    Joksimović Vesna

    2003-01-01

    Full Text Available On the large forest areas, where the measures of soil quality improvement are absent or rarely undertaken, the rocks are the sources of a great number of elements in plant nutrition and one of the factors affecting the contents of some elements in plants. The aim of the study is to determine the differences in the contents of Cu, Zn, Mn, Ni, Fe, Cd, Co, Pb and Cr in the beech leaves developed in the same climate conditions, on morphologically similar terrains, composed of different types of sedimentary rocks. This paper presents the study results of the contents of the above elements in argillites, sandstones (grauwackes and microconglomerates occurring as the parent rocks in high beech forests in the region of GJ Bogovina (Brezovica Južni Kučaj and in the leaves of beech developed on these rocks.

  16. Development of an analogue multiplexed regulation for periodic 1. order delayed processes; Etude et realisation d'une regulation analogique multiplexee pour processus aperiodiques du 1. ordre avec retard pur

    Energy Technology Data Exchange (ETDEWEB)

    Amblard, J C [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1967-07-15

    The present note deals with the study regulations of the sampled type, for 1. order process with simple delay. In order to obtain a good stability in such regulations, together with acceptable performances, it is interesting to use polynomial type correctors acting directly on the sampled error signals. The active elements of these correctors can be shared by all the channels to be controlled. Furthermore, the determination of the correction parameters results from an optimal study of the system. In the second part is described the construction of a multiplexed regulation for diffusion ovens. (author) [French] La presente note concerne l'etude des regulations de type echantillonne, pour processus du 1. ordre avec retard pur. Pour obtenir une bonne stabilite de telles regulations, ainsi que des performances correcte il est interessant d'utiliser des correcteurs de type polynomial, agissant directement sur les signaux d'erreur echantillonnes. Les elements actifs de ces correcteurs peuvent etre pris communs a toutes les voies a controler. D'autre part, la determination des parametres de correction decoula d'une etude optimale du systeme. Dans une seconde partie on decrit la realisation d'une regulation multiplexee de fours a diffusion. (auteur)

  17. The validity of generic trends on multiple scales in rock-physical and rock-mechanical properties of the Whitby Mudstone, United Kingdom

    NARCIS (Netherlands)

    Douma, L.A.N.R.; Primarini, M.I.W.; Houben, M.E.; Barnhoorn, A.

    Finding generic trends in mechanical and physical rock properties will help to make predictions of the rock-mechanical behaviour of shales. Understanding the rock-mechanical behaviour of shales is important for the successful development of unconventional hydrocarbon reservoirs. This paper presents

  18. Loading-unloading pressure-volume curves for rocks

    International Nuclear Information System (INIS)

    Stephens, D.R.; Lilley, E.M.

    1970-01-01

    The stress-strain codes (SOC and TENSOR) used to calculate phenomenology of nuclear explosion for the Plowshare Program require inter alia the pressure-volume relationships of the earth media. In this paper we describe a rapid and accurate method to obtain pressure-volume data to 40 kb at 25 deg. C for rocks. These experimental results may also be related to the in situ elastic properties of the rock and to other laboratory measurement of properties, such as ultrasonic experiments with pressure and Hugoniot determinations. Qualitative features of the pressure-volume curves can be related to the initial porosity of the rock. A porous rock is usually quite compressible at low pressures. If the porosity is in the form of narrow cracks, the cracks are closed at a pressure of about 3 to 6 kb, after which the rock is much less compressible. If the porosity is in the form of spherical pores, it is not necessarily removed even at pressures of 40 kb, depending on the strength of the rock, and the compressibility is higher at all pressures than for a similar rock containing no porosity. Data for water-saturated samples show the phase transformation due to free water at about 10 and 22 kb. However, the presence of 'nonliquid' water, which is loosely contained within the lattice of clay or zeolitic minerals or adsorbed on particle surfaces, is also observed. (author)

  19. Loading-unloading pressure-volume curves for rocks

    Energy Technology Data Exchange (ETDEWEB)

    Stephens, D R; Lilley, E M [Lawrence Radiation Laboratory, University of California, Livermore, CA (United States)

    1970-05-01

    The stress-strain codes (SOC and TENSOR) used to calculate phenomenology of nuclear explosion for the Plowshare Program require inter alia the pressure-volume relationships of the earth media. In this paper we describe a rapid and accurate method to obtain pressure-volume data to 40 kb at 25 deg. C for rocks. These experimental results may also be related to the in situ elastic properties of the rock and to other laboratory measurement of properties, such as ultrasonic experiments with pressure and Hugoniot determinations. Qualitative features of the pressure-volume curves can be related to the initial porosity of the rock. A porous rock is usually quite compressible at low pressures. If the porosity is in the form of narrow cracks, the cracks are closed at a pressure of about 3 to 6 kb, after which the rock is much less compressible. If the porosity is in the form of spherical pores, it is not necessarily removed even at pressures of 40 kb, depending on the strength of the rock, and the compressibility is higher at all pressures than for a similar rock containing no porosity. Data for water-saturated samples show the phase transformation due to free water at about 10 and 22 kb. However, the presence of 'nonliquid' water, which is loosely contained within the lattice of clay or zeolitic minerals or adsorbed on particle surfaces, is also observed. (author)

  20. Transfer of extensor digiti minimi and extensor carpi ulnaris nerve branches to the intrinsic motor nerve branches: A histological study on cadaver.

    Science.gov (United States)

    Namazi, H; Haji Vandi, S

    2017-06-01

    In cases of high ulnar and median nerve palsy, result of nerve repair in term of intrinsic muscle recovery is unsatisfactory. Distal nerve transfer can alleviate the regeneration time and improve the results. Transfer of the extensor digiti minimi (EDM) and extensor carpi ulnaris (ECU) nerve branches to the deep branch of ulnar nerve (DBUN)/recurrent branch of median nerve (RMN) at wrist had been used to restore intrinsic hand function but, incomplete recovery occurred. The axon count at the donor nerve has a strong influence on the final results. This cadaveric study aims to analyses the histology of this nerve transfer to evaluate whether these donor nerves are suitable for this transfer or another donor nerve may be considered. Ten cadaveric upper limbs dissected to identify the location of the EDM, ECU, RMN and DBUN. Surface area, fascicle count, and axon number was determined by histological methods. The mean of axon number in the EDM, ECU, RMN and DBUN branches was 5931, 7355, 30960 and 35426, respectively. In this study, the number of axons in the EDM and ECU branches was 37% (13281/35426) of that in the DBUN. Also, the number of axons in the EDM and ECU branches was 42% (13281/30960) of that in the RMN. The axon count data showed an unfavorable match between the EDM, ECU and DBUN/RMN. Therefore, it is suggested that another donor nerve with higher axon number to be considered. Cadaver study (histological study). Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  1. Rock mechanics and the economics of cut-and-fill mining

    Energy Technology Data Exchange (ETDEWEB)

    Almgren, G.

    1980-05-15

    The application of rock mechanics to mining has great economic potential. Factors such as loss of ore, rock-dilution, possibilities of machanization and rock support are all influenced by the degree of rock mechanics involvement. In particular loss of ore is limited by the correct dimensioning of pillars and remnants. Rock-dilution, depending upon caving, can in the same way be mastered by the right dimensions of stopes and pillars and of rock supporting. Possibilities of mechanization depend upon sizes of drifts and stopes, stope availabilities and access to the stopes, all depending upon a considered rock mechanic investigation. Also shut-downs in the stopes owing to caving can be affected in the same way. Consequences on the mining economy for cut-and-fil mining are illustrated concerning loss of ore, rock-dilution, mechanization levels and rock support. The biggest influence can be made on rock-dilution and mechanization. Under special circumstances loss of ore can be of the same magnitude, namely if the ore production per year is directly influenced by the loss of ore and can not be compensated by other mining activities. Rock support is of less economic importance compared with rock-dilution and mechanization, presupposed no less of ore-production.

  2. Study of the machining of uranium carbide rods obtained by continuous casting under electronic bombardment; Etude de l'usinage de barreaux de carbure d'uranium obtenus par coulee continue sous bombardement electronique

    Energy Technology Data Exchange (ETDEWEB)

    Rousset, P; Accary, A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1965-07-01

    The authors consider the various methods of machining uranium mono-carbide and compare them critically in the case of their application to uranium carbide obtained by fusion under an electronic bombardment and continuous casting. This study leads them to propose two mechanical machining methods: cylindrical rectification and center-less rectification, preceded by a preliminary roughing out of a cylinder, the latter appearing more suitable. A study of the machining yields as a function of the diameter of the rough bars and of the diameter of the finished rods has shown that an optimum value of the rough bar diameter exists for each value of the finished rod diameter. It is found that the yield increases as the diameter itself increases, this yield rising from 45 per cent to around 70 per cent as the diameter of the rough bars increases from 25-26 mm to 37-38 mm. (authors) [French] Les auteurs envisagent les differentes methodes d'usinage du monocarbure d'uranium et se livrent a une etude critique de celles-ci, dans le cas de leur application a l'usinage de barreaux de carbure d'uranium obtenus par fusion sous bombardement electronique et coulee continue. Cette etude les conduit a proposer deux methodes d'usinage mecanique: la rectification cylindrique et la rectification 'centerless', precedee d'un ebauchage par carottage, la seconde paraissant la plus appropriee. L'etude des rendements d'usinage en fonction du diametre des barreaux bruts et du diametre des barreaux finis, a mis en evidence une valeur optimale du diametre des barreaux bruts pour chaque valeur du diametre des barreaux usines. Elle a montre que le rendement croit lorsque le diametre croit lui-meme, ce rendement passant d'environ 45 pour cent a environ 70 pour cent, lorsque le diametre des barreaux bruts passe de 25-26 mm a 37-38 mm.

  3. Rock bed heat accumulators. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Riaz, M.

    1977-12-01

    The principal objectives of the research program on rock bed heat accumulators (or RBHA) are: (1) to investigate the technical and economic feasibility of storing large amounts of thermal energy (in the tens of MWt range) at high temperature (up to 500/sup 0/C) over extended periods of time (up to 6 months) using native earth or rock materials; (2) to conduct studies to establish the performance characteristics of large rock bed heat accumulators at various power and temperature levels compatible with thermal conversion systems; and (3) to assess the materials and environmental problems associated with the operation of such large heat accumulators. Results of the study indicate that rock bed heat accumulators for seasonal storage are both technically and economically feasible, and hence could be exploited in various applications in which storage plays an essential role such as solar power and total energy systems, district and cogeneration heating systems.

  4. Small-scale bentonite injection test on rock

    International Nuclear Information System (INIS)

    Pusch, R.

    1978-03-01

    When radiactive waste is disposed a sealing of the rock is very valuable since it reduces the rate of water percolation and diffusion. In an earlier report injection of bentonite gels by means of over-pressure and subsequent electrophoresis has been suggested. The present report describes a rock test series where bentonite injection was applied. For the test an approximately cubical block of about 1 m 3 was selected. The rock type was diorite with a fairly high frequency of quartz denses. The block was kept in a basin during the test in order to maintain the water saturation. Holes were bored in the block. A bentonite slurry with 1000 percent water content was injected. It was shown that the bentonite had a sealing effect but the depth of extrusion into rock joints was not large because of gelation. Electro-Kinetic injection of montmorillonite was found to be a more promising technique for rock lightening

  5. Agronomic behavior of phosphoric rock from Bahia Inglesa using isotopic techniques. 1. Field trial with concentrated and non concentrated rock

    International Nuclear Information System (INIS)

    Pino N, I.; Casa G, L.

    1989-01-01

    With the aim to assess the agronomic behaviour of the phosphoric rock from Bahia Inglesa, a field trial was carried out with concentrated and non concentrated 100 mesh sieved rock. The method of isotopic dilution was used with TSP labeled P32 (TSP-P32) as standard fertilizer. Total dry matter, total P by colorimetry and P32 by liquid scintillation using the Cerenkov effect were measured. Both agronomic and isotope parameters were analyzed. The concentrated phosphoric rock was 3.7 times better than the same non concentrated rock. These also was a positive effect from non concentrated at 400 kg P205/ha dose. This effect was attributed to a higher saturation in the points of P sorption. The TSP showed a better behaviour than the phosphoric rock under study. (author)

  6. Perfect zircon for rock dating no fairy tale

    International Nuclear Information System (INIS)

    Anon

    2000-01-01

    The scheme used to date rocks is based on the radioactive decay of uranium. Minute traces of uranium locked inside the zircon crystals have been decaying over aeons, producing lead. Scientists know that the decay occurs at a fixed rate and how quickly it happens. By measuring the relative amounts of uranium and lead encased in the crystals, scientists can determine how old the rock is. But sometimes lead is lost from zircon crystals via processes such as weathering (if the rocks were exposed on the surface) or deformation and metamorphism (if the rocks had crystallised deep in the earth and been subjected to high temperatures and pressure). Hence the special nature of the Temora rocks- a 417 million years old zirconium-containing rock which have been partially exposed in recent times in a remote paddock in NSW, Australia. SHRIMP dating was used for initial tests on the Temora rocks. Then, in December last year, the sample was sent to the world-recognised authority, Canada's Royal Ontario Museum, for independent analysis and dating via chemical decomposition. The museum confirmed the near perfect quality of the zircon and its age

  7. ROCK as a therapeutic target for ischemic stroke.

    Science.gov (United States)

    Sladojevic, Nikola; Yu, Brian; Liao, James K

    2017-12-01

    Stroke is a major cause of disability and the fifth leading cause of death. Currently, the only approved acute medical treatment of ischemic stroke is tissue plasminogen activator (tPA), but its effectiveness is greatly predicated upon early administration of the drug. There is, therefore, an urgent need to find new therapeutic options for acute stroke. Areas covered: In this review, we summarize the role of Rho-associated coiled-coil containing kinase (ROCK) and its potential as a therapeutic target in stroke pathophysiology. ROCK is a major regulator of cell contractility, motility, and proliferation. Many of these ROCK-mediated processes in endothelial cells, vascular smooth muscle cells, pericytes, astrocytes, glia, neurons, leukocytes, and platelets are important in stroke pathophysiology, and the inhibition of such processes could improve stroke outcome. Expert commentary: ROCK is a potential therapeutic target for cardiovascular disease and ROCK inhibitors have already been approved for human use in Japan and China for the treatment of acute stroke. Further studies are needed to determine the role of ROCK isoforms in the pathophysiology of cerebral ischemia and whether there are further therapeutic benefits with selective ROCK inhibitors.

  8. Syntheses and study of pyrrolidinic nitroxide free radicals. Preparation of a nitroxide-type stable bi-radical; Synthese et etudes de radicaux libres nitroxydes pyrrolidiniques. Preparation d'un biradical stable du type nitroxyde

    Energy Technology Data Exchange (ETDEWEB)

    Dupeyre, R M [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires, Laboratoire de chimie organique physique

    1967-12-01

    Syntheses and study of pyrrolidinic nitroxide free radicals: These radicals are obtained by oxidation, with hydrogen peroxide, of pyrrolidinic amines prepared from triacetonamine by ring contraction. The U. V,, I. R, and E.P.R. spectral characteristics have been determined. The oxidation of these amines with hydrogen peroxide has led also to rupture of the pentagonal ring; some of the decomposition products have been identified. The high chemical stability of the nitroxide group has made it possible to synthesize and study a stable bi-radical. (author) [French] Syntheses et etudes de radicaux libres nitroxydes pyrrolidiniques: Ces radicaux sont obtenus par oxydation l'eau oxygenee d'amines pyrrolidiniques preparees a partir de la triacetonamine par contraction de cycle. Les caracteristiques spectroscopiques ultra-violettes, infra-rouge et resonance paramagnetique sont determinees. Cependant, 1'oxydation de ces amines a l'eau oxygenee a entraine la coupure du cycle pentagonal et identification de certaines substances de decomposition obtenues. La grande stabilite chimique de groupement nitroxyde a permis la synthese et l'etude d'un biradical stable. (auteur)

  9. Rock engineering applications, 1991

    International Nuclear Information System (INIS)

    Franklin, J.A.; Dusseault, M.B.

    1991-01-01

    This book demonstrates how to apply the theories and principles of rock engineering to actual engineering and construction tasks. It features insights on geology for mining and tunnelling applications. It is practical resource that focuses on the latest technological innovation and examines up-to-date procedures used by engineers for coping with complex rock conditions. The authors also discuss question related to underground space, from design approaches to underground housing and storage. And they cover the monitoring of storage caverns for liquid and gaseous products or toxic and radioactive wastes

  10. Predicting rock bursts in mines

    Science.gov (United States)

    Spall, H.

    1979-01-01

    In terms of lives lost, rock bursts in underground mines can be as hazardous as earthquakes on the surface. So it is not surprising that fo the last 40 years the U.S Bureau of Mines has been using seismic methods for detecting areas in underground mines where there is a high differential stress which could lead to structural instability of the rock mass being excavated.

  11. Cuttability Assessment of Selected Rocks Through Different Brittleness Values

    Science.gov (United States)

    Dursun, Arif Emre; Gokay, M. Kemal

    2016-04-01

    Prediction of cuttability is a critical issue for successful execution of tunnel or mining excavation projects. Rock cuttability is also used to determine specific energy, which is defined as the work done by the cutting force to excavate a unit volume of yield. Specific energy is a meaningful inverse measure of cutting efficiency, since it simply states how much energy must be expended to excavate a unit volume of rock. Brittleness is a fundamental rock property and applied in drilling and rock excavation. Brittleness is one of the most crucial rock features for rock excavation. For this reason, determination of relations between cuttability and brittleness will help rock engineers. This study aims to estimate the specific energy from different brittleness values of rocks by means of simple and multiple regression analyses. In this study, rock cutting, rock property, and brittleness index tests were carried out on 24 different rock samples with different strength values, including marble, travertine, and tuff, collected from sites around Konya Province, Turkey. Four previously used brittleness concepts were evaluated in this study, denoted as B 1 (ratio of compressive to tensile strength), B 2 (ratio of the difference between compressive and tensile strength to the sum of compressive and tensile strength), B 3 (area under the stress-strain line in relation to compressive and tensile strength), and B 9 = S 20, the percentage of fines (point load strengths of rocks using multiple regression analysis). The results suggest that the proposed simple regression-based prediction models including B 3, B 9, and B 9p outperform the other models including B 1 and B 2 and can be used for more accurate and reliable estimation of specific energy.

  12. Marked dietary differences between sympatric feral rock doves and ...

    African Journals Online (AJOL)

    Although feral rock doves Columba livia and rock pigeons C. guineafly daily in mixed flocks between roosting and nesting sites in Cape Town, South Africa, they feed separately in farmlands north of the city during the austral summer. Examination of the crop contents of 32 feral rock doves and 48 rock pigeons revealed that ...

  13. SEPA (Service d'etudes, de Procedes et Analyses)

    International Nuclear Information System (INIS)

    2017-01-01

    The SEPA (Service d'etudes, de Procedes et Analyses), is an engineering department specializing in the analysis and processing of uranium ore. It comes from a long tradition of mining in France that began sixty-five years ago with the French Atomic Energy Commission (CEA) and that has been carried on by COGEMA and then Areva. SEPA brings a combination of experience and excellence to its activities thanks to its multidisciplinary staff (mineralogists, chemists, mechanical engineers, instrumentation specialists...), who come from diverse cultural backgrounds. Today, the SEPA draws on its wealth of know-how and expertise to devise and develop new methods for processing and valorizing ores everywhere in the world. Its mission is to: - Develop and conduct laboratory tests on methods for processing uranium and other valuable elements such as molybdenum, vanadium, rare earths, niobium, tantalum and thorium; - Analyze ores obtained during prospecting at locations all over the world; -Serve as an advisor in the commissioning of Areva industrial units and ore processing plants; -Perform environmental analyses during the full period of mining operations; -Conduct audits and provide advice on processes and analysis methods; -Carry out research and development in all aspects of minerals treatment (including the filing of patents). The SEPA combines experience, skills and a global approach to technologies used in ore processing. Its role is to continually improve the processes for extracting, processing and valorizing ores while protecting the environment

  14. Study of the tributyl phosphate - 30% dodecane solvent; Etude du solvant phosphate tributylique - 30 % dodecane

    Energy Technology Data Exchange (ETDEWEB)

    Leroy, P [Commissariat a l' Energie Atomique, Fontenay-aux-Roses. Centre d' Etudes Nucleaires, 92 (France)

    1967-07-01

    This study, originating mainly from a literature survey, gives the principal chemical and physical features of the tributyl-phosphate (TBP) agent diluted at 30 volumes per cent in dodecane. The mixture is a very commonly used extractant in nuclear fuel processing. In this paper, the main following points are reported: -) the components (TBP and diluents) -) the TBP-diluents systems (non-loaded), -) the TBP-diluents-water systems, -) TBP-diluents-water-nitric acid systems, and -) industrial solvents. (author) [French] Cette etude, d'origine bibliographique, regroupe les caracteristiques physico-chimiques essentielles du phosphate tributylique (TBP) dilue a 30% en volume dans du dodecane. Ce melange constitue un agent d'extraction tres utilise dans le traitement des combustibles nucleaires. Les principaux points traites sont les suivants: -) les constituants (TBP et diluants), -) les systemes TBP-diluants non charges, -) les systemes TBP-diluants-eau, -) les systemes TBP-diluants-eau-acide nitrique, et -) les solvants industriels. (auteur)

  15. Assessment of rock mass decay in artificial slopes

    NARCIS (Netherlands)

    Huisman, M.

    2006-01-01

    This research investigates the decay of rock masses underlying slopes, and seeks to quantify the relations of such decay with time and geotechnical parameters of the slope and rock mass. Decay can greatly affect the geotechnical properties of rocks within engineering timescales, and may induce a

  16. Studies on the radiation absorption characteristics of various rocks

    International Nuclear Information System (INIS)

    Rahman, K.N.; Abdullah, S.A.; Gazzaz, M.A.

    1984-05-01

    Radiation absorption characteristics of nine different rocks, namely, ferrugenous quartz, metabasalt, larvikite, coarse grained diorite, coarse grained granite, coarse grained alkali granite, marble, quartz mica schist, and metamorphosed rock are studied. The rocks were collected from Jeddah, Makkah, Mina and Taif areas. Special attention was given on the availability, compactness, physical formation and uniform composition in selecting the rocks. The rocks were identified by optical method and their elemental composition determined by chemical analysis. The data were used to calculate the effective atomic numbers, half value layers mass and linear attenuation coefficients. The half value layers and the linear attenuation coefficientsof these rocks were determined experimentally using Am-241, Cs-137,and Co-60 sources. The results are compared with those obtained by theoretical calculations and agrre within 10%. Most of the rocks show much higher radiation attenuation characteristics than the standard concrete. Rocks containing higher percentage of Fe, Ca, Ti, and Mn show much higher radiation absorption characteristics than concrete. Only granites are found to be almost equivalent to concrete. 12 Ref

  17. Using Rock Music To Teach History.

    Science.gov (United States)

    Hoffman, Paul Dennis

    1985-01-01

    A secondary history teacher describes how he uses rock and roll music to help students study and interpret modern American history. Besides being a lot of fun to teach, a rock unit makes students realize that even contemporary music has a place in history. (RM)

  18. Mechanical dispersion in fractured crystalline rock systems

    International Nuclear Information System (INIS)

    Lafleur, D.W.; Raven, K.G.

    1986-12-01

    This report compiles and evaluates the hydrogeologic parameters describing the flow of groundwater and transport of solutes in fractured crystalline rocks. This report describes the processes of mechanical dispersion in fractured crystalline rocks, and compiles and evaluates the dispersion parameters determined from both laboratory and field tracer experiments. The compiled data show that extrapolation of the reliable test results performed over intermediate scales (10's of m and 10's to 100's of hours) to larger spatial and temporal scales required for performance assessment of a nuclear waste repository in crystalline rock is not justified. The reliable measures of longitudinal dispersivity of fractured crystalline rock are found to range between 0.4 and 7.8 m

  19. Mechanical properties of rock at high temperatures

    International Nuclear Information System (INIS)

    Kinoshita, Naoto; Abe, Tohru; Wakabayashi, Naruki; Ishida, Tsuyoshi.

    1997-01-01

    The laboratory tests have been performed in order to investigate the effects of temperature up to 300degC and pressure up to 30 MPa on the mechanical properties of three types of rocks, Inada granite, Sanjoume andesite and Oya tuff. The experimental results indicated that the significant differences in temperature dependence of mechanical properties exist between the three rocks, because of the difference of the factors which determine the mechanical properties of the rocks. The effect of temperature on the mechanical properties for the rocks is lower than that of pressure and water content. Temperature dependence of the mechanical properties is reduced by increase in pressure in the range of pressure and temperature investigated in this paper. (author)

  20. Studies of magnetism with inelastic scattering of cold neutrons; Etudes de magnetisme realisees a l'aide de la diffusion inelastique de neutrons froids

    Energy Technology Data Exchange (ETDEWEB)

    Jacrot, B [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    Inelastic scattering of cold neutrons can be used to study some aspects of magnetism: spins waves, exchange integrals, vicinity of Curie point. After description of the experimental set-up, several experiments, in the fields mentioned above, are analysed. (author) [French] La technique de diffusion inelastique des neutrons froids est utilisee pour etudier certains aspects du magnetisme: ondes de spins, integrales d'echange, etude au voisinage du point de Curie, etc. Apres une description de l'appareillage, on analyse diverses experiences effectuees dans les domaines enumeres plus haut. (auteur)

  1. Marked dietary differences between sympatric feral rock doves and ...

    African Journals Online (AJOL)

    1993-06-24

    Jun 24, 1993 ... Although feral rock doves Columba Iivia and rock pigeons C. guinea fly daily in mixed flocks between roosting and nesting sites in Cape Town, South Africa, they feed separately in farmlands north of the city during the austral summer. Examination of the crop contents of 32 feral rock doves and 48 rock ...

  2. Summary of rock mechanics work completed for Posiva before 2005

    International Nuclear Information System (INIS)

    Hudson, J.A.; Johansson, E.

    2006-06-01

    To plan Posiva's rock mechanics work for 2005-2006 and beyond, it was necessary to have a clear understanding of the individual components of work that had been completed for Posiva before 2005 and to assess the cumulative rock mechanics knowledge base. This review summarizes the 80 individual completed documents, which include rock mechanics reports and other reports containing rock mechanics material. They are summarised within a structured framework of rock properties, analyses and the effects of excavation. Following the introductory section, the method of structuring the rock mechanics information is presented. Then the tabulation highlighting the features of all the previous rock mechanics work is explained. This tabulation forms the Appendix; the content of each rock mechanics report that has been produced is summarized via the table headings of document number, subject area, document reference, subject matter, objectives, methodology, highlighted figures, conclusions and comments. In addition to the direct usefulness of the tabulation in summarizing each report, it has been possible to draw overall conclusions: Information has also been obtained worldwide, especially Sweden and Canada; The rock stress state has been measured but further work is required related both to in situ measurements and numerical modelling to study, e.g., the influence of deformation zones on the local stress state; The intact rock has been extensively studied: there is a good knowledge of the parameters and their values, including the anisotropic nature of the site rocks; The geometry of the fractures is included in the geological characterisation but more rock mechanics work is required on the mechanical properties; The mechanical properties of the deformation zones have not been studied in detail; The thermal properties of the site rock are relatively well understood; A new classification has been developed for constructability and long-term safety assessment. This classification

  3. Towards a comprehensive classification of igneous rocks and magmas

    Science.gov (United States)

    Middlemost, Eric A. K.

    1991-08-01

    The IUGS Subcommission on the Systematics of Igneous Rocks has recently published an excellent book on the classification of these rocks. This event has shifted the vexed question of classification towards the top of the agenda in igneous petrology. Over the years the Subcommission has used many different criteria to establish the positions of the boundaries between the various common igneous rocks. It now has to adopt a holistic approach and develop a comprehensive, coherent classification that is purged of all the minor anomalies that arise between the various classifications that it has approved. It is appreciated that the Subcommission's classification was never intended to have any genetic implications; however, it is suggested that an ideal classification should he presented in such a way that it is able to group rocks into an order that directs attention to petrogenetic relationships between individual rocks and larger groups of rocks. Unfortunately, many of the Subcommission's definitions are Earth chauvinistic; for example, igneous rocks are defined as being those rocks that solidified from a molten state either within or on the surface of the Earth. Nowhere in the book is it acknowledged that during the past 20 years, while the Subcommission has been framing its many recommendations, a whole new science of planetary petrology has subsumed classical petrology. In any new edition of the book, the Subcommission should acknowledge that rocks are essentially the solid materials of which planets, natural satellites and other broadly similar cosmic bodies are made. The Subcommission should also explicitly recognise that igneous rocks can be divided into either a main sequence of essentially common rocks or a number of supplementary clans of special rocks that evolved outside the main sequence. It is hoped that in the near future the Subcommission will rescind its recommendation that the TAS classification should be regarded as an adjunct to its more traditional

  4. Whole-rock U-Pb dating of the Shuijingtuo formation sedimentary rocks in the Yangtze Gorge

    International Nuclear Information System (INIS)

    Zheng, Y.F.; Huang, B.

    1990-01-01

    Black shale and enclosed limestone lenticule from Lower Cambrian Shuijingtuo Formation in the Yangtze Gorge is successfully dated by whole-rock U-Pb method. The results yield a concordant age of about 573±14 Ma, in excellent agreement with both stratigraphic and palaeontologic evidence. The whole-rock U-Pb method can provide a reliable approach for age determination of sedimentary stratum. (orig.) [de

  5. Brit Crit: Turning Points in British Rock Criticism 1960-1990

    DEFF Research Database (Denmark)

    Gudmundsson, Gestur; Lindberg, U.; Michelsen, M.

    2002-01-01

    had national specific traits and there have been more profound paradigm shifts than in American rock criticism. This is primarily explained by the fact that American rock criticism is more strongly connected to general cultural history, while the UK rock criticism has been more alienated from dominant......The article examines the development of rock criticism in the United Kingdom from the perspective of a Bourdieuan field-analysis. Early British rock critics, like Nik Cohn, were international pioneers, a few years later there was a strong American influence, but British rock criticism has always...... culture and more linked to youth culture. However, also in the UK rock criticism has been part and parcel of the legitimation of rock culture and has moved closer to dominant fields and positions in the cultural hierarchy....

  6. Magnetic mineralogy and rock magnetic properties of silicate and carbonatite rocks from Oldoinyo Lengai volcano (Tanzania)

    Science.gov (United States)

    Mattsson, H. B.; Balashova, A.; Almqvist, B. S. G.; Bosshard-Stadlin, S. A.; Weidendorfer, D.

    2018-06-01

    Oldoinyo Lengai, a stratovolcano in northern Tanzania, is most famous for being the only currently active carbonatite volcano on Earth. The bulk of the volcanic edifice is dominated by eruptive products produced by silica-undersaturated, peralkaline, silicate magmas (effusive, explosive and/or as cumulates at depth). The recent (2007-2008) explosive eruption produced the first ever recorded pyroclastic flows at this volcano and the accidental lithics incorporated into the pyroclastic flows represent a broad variety of different rock types, comprising both extrusive and intrusive varieties, in addition to various types of cumulates. This mix of different accidental lithics provides a unique insight into the inner workings of the world's only active carbonatite volcano. Here, we focus on the magnetic mineralogy and the rock magnetic properties of a wide selection of samples spanning the spectrum of Oldoinyo Lengai rock types compositionally, as well from a textural point of view. Here we show that the magnetic properties of most extrusive silicate rocks are dominated by magnetite-ulvöspinel solid solutions, and that pyrrhotite plays a larger role in the magnetic properties of the intrusive silicate rocks. The natrocarbonatitic lavas, for which the volcano is best known for, show distinctly different magnetic properties in comparison with the silicate rocks. This discrepancy may be explained by abundant alabandite crystals/blebs in the groundmass of the natrocarbonatitic lavas. A detailed combination of petrological/mineralogical studies with geophysical investigations is an absolute necessity in order to understand, and to better constrain, the overall architecture and inner workings of the subvolcanic plumbing system. The results presented here may also have implications for the quest in order to explain the genesis of the uniquely natrocarbonatitic magmas characteristic of Oldoinyo Lengai.

  7. Experimental study of contamination by inhalation of radioactive iodine aerosols. Biological balance; Etude experimentale de la contamination par inhalation d'aerosols d'iode radioactif bilan biologique

    Energy Technology Data Exchange (ETDEWEB)

    Marble, G [Commissariat a l' Energie Atomique, 92 - Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1968-07-01

    Several articles have been published concerning research into contamination produced by inhalation of radioactive iodine aerosols in monkeys. Results dealing with the biological balance of this contamination are presented and discussed in this report. (author) [French] L'etude experimentale de la contamination par inhalation d'aerosols d'iode radioactif effectuee chez le singe a fait l'objet de plusieurs publications. Les resultats concernant le bilan biologique de cette contamination sont presentes et discutes dans ce rapport. (auteur)

  8. Studies of iron carbon alloys; Contribution a l'etude des alliages dilues de carbone dans le fer {alpha}

    Energy Technology Data Exchange (ETDEWEB)

    Anagnostopoulos, T [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1971-07-01

    Precipitation of carbon in {alpha} iron during a thermal treatment was followed using the magnetic after effect. A study was made of the influence of different parameters such as quenching speed, annealing rate, carbon concentration with or without impurity, irradiation effects. A transient sur-saturation occurs during dissolution of carbon in iron at 500 C. (author) [French] La precipitation du carbone dans le fer au cours d'un traitement thermique a ete suivie au moyen du trainage magnetique. L'etude de differents parametres tels que: vitesse de trempe, mode de recuit, concentration en carbone, presence d'impuretes, effet d'une irradiation, ont ete menes a bien. Un phenomene de sursaturation transitoire au cours de la remise en solution a 500 C a ete mis en evidence. (auteur)

  9. Rock Burst Monitoring by Integrated Microseismic and Electromagnetic Radiation Methods

    Science.gov (United States)

    Li, Xuelong; Wang, Enyuan; Li, Zhonghui; Liu, Zhentang; Song, Dazhao; Qiu, Liming

    2016-11-01

    For this study, microseismic (MS) and electromagnetic radiation (EMR) monitoring systems were installed in a coal mine to monitor rock bursts. The MS system monitors coal or rock mass ruptures in the whole mine, whereas the EMR equipment monitors the coal or rock stress in a small area. By analysing the MS energy, number of MS events, and EMR intensity with respect to rock bursts, it has been shown that the energy and number of MS events present a "quiet period" 1-3 days before the rock burst. The data also show that the EMR intensity reaches a peak before the rock burst and this EMR intensity peak generally corresponds to the MS "quiet period". There is a positive correlation between stress and EMR intensity. Buckling failure of coal or rock depends on the rheological properties and occurs after the peak stress in the high-stress concentration areas in deep mines. The MS "quiet period" before the rock burst is caused by the heterogeneity of the coal and rock structures, the transfer of high stress into internal areas, locked patches, and self-organized criticality near the stress peak. This study increases our understanding of coal and rock instability in deep mines. Combining MS and EMR to monitor rock burst could improve prediction accuracy.

  10. Eclogite facies rocks

    National Research Council Canada - National Science Library

    Carswell, D. A

    1990-01-01

    ... of eclogite evolution and genesis. The authors present a thorough treatment of the stability relations and geochemistry of these rocks, their intimate association with continental plate collision zones and suture zones...

  11. Eclogite facies rocks

    National Research Council Canada - National Science Library

    Carswell, D. A

    1990-01-01

    .... This is the first volume to provide a coherent and comprehensive review of the conditions necessary for the formation of eclogites and eclogite facies rocks and assemblages, and a detailed account...

  12. THM-coupled modeling of selected processes in argillaceous rock relevant to rock mechanics; THM-Gekoppelte Modellierung ausgewaehlter gesteinsmechanisch relevanter Prozesse im Tongestein

    Energy Technology Data Exchange (ETDEWEB)

    Czaikowski, Oliver [Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) mbH, Braunschweig (Germany). Repository Safety Research Div.

    2012-08-15

    Scientific investigations in European countries other than Germany concentrate not only on granite formations (Switzerland, Sweden) but also on argillaceous rock formations (France, Switzerland, Belgium) to assess their suitability as host and barrier rock for the final storage of radioactive waste. In Germany, rock salt has been under thorough study as a host rock over the past few decades. According to a study by the German Federal Institute for Geosciences and Natural Resources, however, not only salt deposits but also argillaceous rock deposits are available at relevant depths and of extensions in space which make final storage of high-level radioactive waste basically possible in Germany. Equally qualified findings about the suitability/unsuitability of non-saline rock formations require fundamental studies to be conducted nationally because of the comparatively low level of knowledge. The article presents basic analyses of coupled mechanical and hydraulic properties of argillaceous rock formations as host rock for a repository. The interaction of various processes is explained on the basis of knowledge derived from laboratory studies, and open problems are deduced. For modeling coupled processes, a simplified analytical computation method is proposed and compared with the results of numerical simulations, and the limits to its application are outlined. (orig.)

  13. APPLICATIONS OF BOREHOLE-ACOUSTIC METHODS IN ROCK MECHANICS.

    Science.gov (United States)

    Paillet, Frederick L.

    1985-01-01

    Acoustic-logging methods using a considerable range of wavelengths and frequencies have proven very useful in the in situ characterization of deeply buried crystalline rocks. Seismic velocities are useful in investigating the moduli of unfractured rock, and in producing a continuous record of rock quality for comparison with discontinuous intervals of core. The considerable range of frequencies makes the investigation of scale effects possible in both fractured and unfractured rock. Several specific methods for the characterization of in situ permeability have been developed and verified in the field.

  14. Characteristics and genesis of porphyroclastic lava rock in Xiangshan

    International Nuclear Information System (INIS)

    Zhou Xiaohua; Wang Zhuning

    2012-01-01

    Due to the transitional characteristics of porphyroclastic lava rock in Xiangshan of Jiangxi province, there are a variety of views on its genesis, petrographic attribution. This is because the marginal facies of the porphyroclastic lava is with ignimbrite and tuff characteristics, its transition phase has the characteristics of lava, and its intermediate phase has the feature of sub-volcanic rocks, further more, different texture of the rocks bears transition relationship. By the study of mineral composition, REE pattern, trace elements, isotopes, we put forward that the porphyroclastic lava is formed by the remelting of basement metamorphic rocks. The rocks was believed to be formed in the environment similar to volcanics and subvolcanics, and quite different to plutonic rocks due to the features of low-structure of potassium feldspar phenocrysts and solution mechanism, because the porphyroclastic lava phenocrysts occurs as fragments and maybe related to cryptoexplosion. Therefore the rocks was believed to belong to the volcano extrusive facies. (authors)

  15. Dating oxalate minerals in rock surface deposits

    International Nuclear Information System (INIS)

    Watchman, A.

    2001-01-01

    Oxalate minerals are found associated with rocks, mineral coatings, micro-organisms, plants and animals. They are important in archaeology because they have been found intimately associated with organic binders in prehistoric paints. Oxalate minerals also accumulate in the coatings on rock shelter walls and fallen ceiling slabs where they form the natural backing supports for painting and opaque laminates covering engravings. Though the relationship between anthropogenic activity in a rock shelter and oxalate formation is often uncertain, the radiocarbon age of the oxalate may provide the only means for determining the antiquity of a rock painting or engraving. This paper examines the history of dating oxalate minerals at archaeological sites and provides insights into achieving reliable age estimates. (author). 37 refs., 1 fig., 2 tabs

  16. 10 CFR 960.5-2-9 - Rock characteristics.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Rock characteristics. 960.5-2-9 Section 960.5-2-9 Energy... Rock characteristics. (a) Qualifying condition. The site shall be located such that (1) the thickness and lateral extent and the characteristics and composition of the host rock will be suitable for...

  17. Musical Structure as Narrative in Rock

    Directory of Open Access Journals (Sweden)

    John Fernando Encarnacao

    2011-09-01

    Full Text Available In an attempt to take a fresh look at the analysis of form in rock music, this paper uses Susan McClary’s (2000 idea of ‘quest narrative’ in Western art music as a starting point. While much pop and rock adheres to the basic structure of the establishment of a home territory, episodes or adventures away, and then a return, my study suggests three categories of rock music form that provide alternatives to common combinations of verses, choruses and bridges through which the quest narrative is delivered. Labyrinth forms present more than the usual number of sections to confound our sense of ‘home’, and consequently of ‘quest’. Single-cell forms use repetition to suggest either a kind of stasis or to disrupt our expectations of beginning, middle and end. Immersive forms blur sectional divisions and invite more sensual and participatory responses to the recorded text. With regard to all of these alternative approaches to structure, Judy Lochhead’s (1992 concept of ‘forming’ is called upon to underline rock music forms that unfold as process, rather than map received formal constructs. Central to the argument are a couple of crucial definitions. Following Theodore Gracyk (1996, it is not songs, as such, but particular recordings that constitute rock music texts. Additionally, narrative is understood not in (direct relation to the lyrics of a song, nor in terms of artists’ biographies or the trajectories of musical styles, but considered in terms of musical structure. It is hoped that this outline of non-narrative musical structures in rock may have applications not only to other types of music, but to other time-based art forms.

  18. Multiparameter Monitoring and Prevention of Fault-Slip Rock Burst

    Directory of Open Access Journals (Sweden)

    Shan-chao Hu

    2017-01-01

    Full Text Available Fault-slip rock burst is one type of the tectonic rock burst during mining. A detailed understanding of the precursory information of fault-slip rock burst and implementation of monitoring and early warning systems, as well as pressure relief measures, are essential to safety production in deep mines. This paper first establishes a mechanical model of stick-slip instability in fault-slip rock bursts and then reveals the failure characteristics of the instability. Then, change rule of mining-induced stress and microseismic signals before the occurrence of fault-slip rock burst are proposed, and multiparameter integrated early warning methods including mining-induced stress and energy are established. Finally, pressure relief methods targeting large-diameter boreholes and coal seam infusion are presented in accordance with the occurrence mechanism of fault-slip rock burst. The research results have been successfully applied in working faces 2310 of the Suncun Coal Mine, and the safety of the mine has been enhanced. These research results improve the theory of fault-slip rock burst mechanisms and provide the basis for prediction and forecasting, as well as pressure relief, of fault-slip rock bursts.

  19. Study of beam-plasma interactions in the presence of a magnetic field; Etude d'interactions faisceau-plasma en la presence d'un champ magnetique

    Energy Technology Data Exchange (ETDEWEB)

    Etievant, C [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1963-12-15

    The instabilities developing in a 'beam-plasma' system and in a 'double-beam' system in the presence of a magnetic field are discussed theoretically starting from the conductivity tensor expression for a multi-beam system. Oblique propagation is taken into account and this leads to the introduction of certain instability mechanisms which would not appear in the case of a propagation which is purely parallel or perpendicular to the magnetic field. Two experiments are described: a) Study of the collision of two counterstreaming electron beams: An instability has been observed experimentally which leads to the generation of a stationary cyclotron wave having a frequency of {omega}{sub ce}/2. A description is given of the measurement of the interaction frequency, of the wavelength and of the build-up time of the wave. b) Study of a 'beam-plasma' system: A description is given of the measurement of the spectra of excited waves and of the perturbation of the beam velocity distribution at the plasma-exit. This perturbation is very pronounced when 'plasma-plasma' interaction appears in the system. A study into cyclotron oscillations produced in the plasma by excitation due to the passage of the beam is also described in this report. (author) [French] Les instabilites se developpant dans un systeme 'faisceau-plasma' et dans un systeme 'faisceau-faisceau' en la presence d'un champ magnetique sont discutees theoriquement a partir de l'expression du tenseur de conductivite d'un systeme multi-faisceaux. La propagation oblique est prise en consideration, ce qui introduit certains mecanismes d'instabilite qui n'apparaitraient pas pour une propagation purement parallele ou perpendiculaire au champ magnetique. Deux experiences sont decrites: a) Etude de la collision de deux faisceaux d'electrons: Une instabilite conduisant a la generation d'une onde cyclotronique stationnaire a la frequence {omega}{sub ce}/2 a ete observee experimentalement. Les mesures de la frequence d

  20. Technological study of organic fluids; Etudes technologiques des fluides caloporteurs organique

    Energy Technology Data Exchange (ETDEWEB)

    Leveque, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    Under contract to EURATOM (MM. VAN der VENNE and HANNAERT), the C.E.A. and the Progil Society have collaborated on a technological study of the terphenyls. The results obtained from the radiolysis and pyrolysis of the product OM2 (70 p. 100 m-terphenyl, 25 p. 100 o-terphenyl, 5 p. 100 p-terphenyl) are reported. Using two pile loops at temperatures up to 450 deg. C, a phenomena of accelerated pyrolysis on the radiolized material has been demonstrated. Some by-products of the petroleum industry have also been studied, with a view to finding substitutes for terphenyl. (author) [French] Le C.E.A. et la Societe PROGIL ont entrepris en commun sous contrat EURATOM (MM. VAN der VENNE et HANNAERT) une etude technologique des terphenyles. Les resultats de radiolyse et de pyrolyse obtenus sur le produit OM2 (70 p. 100 m-terphenyle, 25 p. 100 o-terphenyle. 5 p. 100 de p-terphenyle) sont exposes. L'exploitation de deux boucles en pile jusqu'a des temperatures de 450 deg. C a mis en evidence un phenomene de pyrolyse acceleree sur le produit radiolyse. On a etudie egalement quelques sous-produits de l'industrie petroliere dans le but de trouver des substituts au terphenyle. (auteur)

  1. The abject gaze and the homosexual body: Flandrin's Figure d'Etude.

    Science.gov (United States)

    Camille, M

    1994-01-01

    This article charts the history of the reception, reproduction and appropriation of a single image that has recently become a kind of "gay icon"--the Figure d'Etude in the Louvre, painted by Hippolyte Flandrin in 1835. Initially no more than a neo-classical academic exercise, the formal emptiness of this picture meant that it could be re-invested and reinscribed with new meanings and new titles at every turn. Emblematic of the anxious visibility/invisibility of the newly discovered homosexual body during a period when the gaze still had to be kept a dark secret, Flandrin's image only "came out" in its later photographic reworkings by Frederick Holland Day and Baron von Gloeden. After being reproduced for a specifically homosexual audience early this century, the popular Romantic pose of the young man curled-up in profile became a standard one, reappearing recently in the photographs of Robert Mapplethorpe. The inactive, abject and inward-turned isolation of the figure with its narcissistic self-absorption makes it, in my view, a profoundly negative stereotype of the gay gaze and the homosexual body. Flandrin's figure nonetheless appears today on gay merchandise world-wide as a sign of our separate and secluded subject positions and our community's unwillingness to radically alter older imposed and inherited classical stereotypes.

  2. Effect of excavation method on rock mass displacement

    International Nuclear Information System (INIS)

    Sato, Toshinori; Kikuchi, Tadashi; Sugihara, Kozo

    1998-01-01

    Rock mass displacement measurements have been performed to understand rock mass behavior and its dependence on excavation method during drift excavation at the Tono mine. Rock mass displacements of 1.46 mm and 0.67 mm have been measured at one meter (0.33D: blasting, 0.42D: machine, D: width of drift) from the walls of drifts excavated by the drill and blasting method and machine, respectively. Numerical analysis of rock mass displacements with Finite Element Method has been performed assuming an excavation disturbed zone. Measured and analysed rock mass displacements are consistent with each other for the drift excavation by the drill and blasting method. The excavation disturbed zone was narrower for the drift excavated by machine than for the drift excavated by the drill and blasting method. (author)

  3. Contribution to the study of recoil species produced by potassium ferrocyanide neutron irradiation; Contribution a l'etude de la reactivite des especes de recul dans le ferrocyanure de potassium irradie aux neutrons thermiques

    Energy Technology Data Exchange (ETDEWEB)

    Meriadec Vernier de Byans, B. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1969-04-01

    The chemical species produced by potassium ferrocyanide neutron irradiation were separated and identified. The study of their behaviour upon thermal annealing has allowed to establish a scheme of reaction as well as a kinetic treatment of the data. Activation energies are determined in different conditions and the effects of radiation dose, oxygen and water of crystallisation upon the activation energies were studied. Preliminary E.S.R. data and its relevance to the decomposition process is also discussed. (authors) [French] On a separe et identifie les differentes especes chimiques produites par irradiation neutronique de ferrocyanure de potassium. L'etude de leur comportement au cours du recuit thermique a permis l'application de differentes cinetiques et l'etablissement d'un schema de reaction. On a deterrmine la valeur des energies d'activation dans differentes conditions de recuit ainsi que l'influence de la dose de radiations, de l'oxygene et de l'eau de cristallisation sur ces energies. Une serie de mesures de resonance paramagnetique electronique a complete cette etude. (auteurs)

  4. The study of some thiazinic and indaminic dye syntheses induced by ionising radiation; Etude de quelques syntheses de colorants thianziniques et indaminiques amorcees par les rayonnements ionisants

    Energy Technology Data Exchange (ETDEWEB)

    Balestic, S [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1961-03-15

    With a view to finding some radiochemical reactions applicable on an industrial scale for evaluating the radioactive waste from nuclear reactors, a systematic study was made of the radiochemical synthesis of thiazinic dyes such as methylene blue and Lauths' violet, on which the first tests were carried out in 1954. The first part of the study concerned the identification and the dosage, during radiolysis, of dyes by means of their absorption spectra after separation from the reaction medium by adsorption chromatography or ion-exchange; other radiolysis products such as ammonium chloride and hydrogen peroxide were also identified. During a later stage by systematically varying the physico-chemical parameters it was possible to determine the most favourable conditions for radio-synthesis; the maximum radiochemical yields obtained had the following values: G (Lauths' violet) 1,65; G (Methylene blue) = 1,75. Furthermore, the study of the influence of variously substituted aminated products on the radiochemical yield showed the possibility of synthesising Bindsehedlers green and Wursters blue by radiochemical methods. Finally the discovery of a fundamental intermediate product, Wursters red, together with the kinetic study of the chemical synthesis of methylene blue made it possible to determine the main stages of the reaction mechanism and to decide which of these stages could be attributed to ionising radiations in the case of the radiochemical synthesis. (author) [French] Dans le but de trouver des reactions radiochimiques susceptibles d'une application industrielle pour valoriser les dechets radioactifs provenant des reacteurs nucleaires, il a ete entrepris une etude systematique de la synthese radiochimique des colorants thiazimiques tels que le Bleu de Methylene et le Violet de Lauth dont les premiers essais ont ete effectues par Loiseleur en 1954. La premiere partie de l'etude a porte sur l'identification et le dosage des colorants formes au cours de la radiolyse

  5. Deep fracturation of granitic rock mass

    International Nuclear Information System (INIS)

    Bles, J.L.; Blanchin, R.; Bonijoly, D.; Dutartre, P.; Feybesse, J.L.; Gros, Y.; Landry, J.; Martin, P.

    1986-01-01

    This documentary study realized with the financial support of the European Communities and the CEA aims at the utilization of available data for the understanding of the evolution of natural fractures in granitic rocks from the surface to deep underground, in various feasibility studies dealing with radioactive wastes disposal. The Mont Blanc road tunnel, the EDF Arc-Isere gallerie, the Auriat deep borehole and the Pyrenean rock mass of Bassies are studied. In this study are more particularly analyzed the relationship between small fractures and large faults, evolution with depth of fracture density and direction, consequences of rock decompression and relationship between fracturation and groundwater [fr

  6. F{sup 19} relaxation in non-magnetic hexafluorides; Contribution a l'etude de la relaxation des fluors dans les hexafluorures non magnetiques

    Energy Technology Data Exchange (ETDEWEB)

    Rigny, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1967-12-01

    The interesting properties of the fluorine magnetic resonance in the hexafluorides of molybdenum, tungsten and uranium, are very much due to large anisotropies of the chemical shift tensors. In the solid phases these anisotropies, the values of which are deduced from line shape studies, allow one to show that the molecules undergo hindered rotations about the metal atom. The temperature and frequency dependence of the fluorine longitudinal relaxation times shows that the relaxation is due to the molecular motion. The dynamical parameters of this motion are then deduced from the complete study of the fluorine relaxation in the rotating frame. In the liquid phases, the existence of anisotropies allows an estimation of the different contributions to the relaxation. In particular, the frequency and temperature dependence of the relaxation shows it to be dominated by the spin-rotation interaction. We have shown that the strength of this interaction can be deduced from the chemical shifts, and the angle through which the molecule rotates quasi-freely can be determined. In the hexafluorides, this angle is roughly one radian at 70 C, and with the help of this value, the friction coefficients which describe the intermolecular interactions are discussed. (author) [French] Les proprietes de la resonance magnetique des fluors dans les hexafluorures de molybdene, tungstene et uranium sont influencees par l'existence de deplacements chimiques tres anisotropes. Dans les phases solides, la valeur de cette anisotropie peut etre determinee par l'analyse des formes de raies et son existence permet de montrer que les molecules sont en rotation empechee autour de leur atome central. L'etude du temps de relaxation longitudinal en fonction de la temperature et de la frequence montre que la relaxation est due aux mouvements moleculaires, aux plus hautes temperatures. Les proprietes dynamiques du mouvement sont obtenues par l'etude complete de la relaxation spin-reseau dans le referentiel

  7. Engineering rock mass classification of the Olkiluoto investigation site

    Energy Technology Data Exchange (ETDEWEB)

    Aeikaes, K. [ed.; Hagros, A.; Johansson, E. [Saanio and Riekkola Consulting Engineers, Helsinki (Finland)] [and others

    2000-06-01

    Olkiluoto in Eurajoki is being investigated as a possible site for the final disposal of spent nuclear fuel from the Finnish nuclear power plants. The selection of the depth, placement and layout of the repository is affected by the constructability of the bedrock. The constructability, in turn, is influenced by several properties of the host rock, such as its Ethology, the extent of fracturing, its hydrogeological properties and rock engineering characteristics and also by the magnitude and orientation of the in situ stresses and the chemistry of the groundwater. The constructability can be evaluated by the application of a rock classification system in which the properties of the host rock are assessed against common rock engineering judgements associated with underground construction. These judgements are based partly on measurements of in situ stresses and the properties of the bedrock determined from rock samples, but an important aspect is also the practical experience which has been gained during underground excavation in similar conditions and rock types. The aim of the engineering rock mass classification was to determine suitable bedrock volumes for the construction of the repository and has used data from the site characterisation programme carried out at Olkiluoto, which consisted of both surface studies and borehole investigations. The classification specifies three categories of constructability - normal, demanding and very demanding. In addition, rock mass quality has also been classified according to the empirical Q-system to enable a comparison to be made. The rock mass parameters that determine the constructability of the bedrock at Olkiluoto depend primarily on the depth and the Ethology, as well as on whether construction takes place in intact or in fractured rock. The differences in the characteristics of intact rock within a single rock type have been shown to be small. The major lithological unit at Olkiluoto, the mica gneiss, lies in the

  8. Method of degassifying a massive of rock

    Energy Technology Data Exchange (ETDEWEB)

    Levin, M M; Krivosheev, V O; Preobrazhenskaia, E I; Talapkerov, A Sh; Taushkin, G T

    1979-05-30

    This invention concerns the mining industry, chiefly the coal industry, and can be used for the degasification of coal layers and interfering rock. The method of preliminary extraction of gas with underground development of burning minerals, including the pumping of gas through a collector, carried in the plane of the degasifying layer, discharged from rock pressure by means of extracting the lower lying layer, is known. However, the given method does not make it possible to degasify the interfering rock. Another method, consisting of the fact that from the mining development in the lateral rock, chambers are made, from which a group of wells are bored, and the latter are united with the gas removing system, is well known. This method has the inadequacy that the well of each chamber is connected to the gas removing system of the pipelines, and this leads to an increase in the price of the method. A new system is presented for the degasification of the massive of rock which is presented in an illustration...... The advantage of the suggested method consists of the fact that material outlays are reduced for the unification of each chamber with the gas removing pipeline, and besides this, the wells, connecting the chambers are drains for the surrounding rock, which increases the effectiveness of the degasification.

  9. Characterization of the rock joint surface. A contribution to DECOVALEX II Task 3 'Constitutive relationships of rock joints'

    International Nuclear Information System (INIS)

    Vuopio, J.; Poellae, J.

    1997-12-01

    In order to understand the effects of spent fuel on the hydraulical behaviour of the rock mass it is necessary to have knowledge about the relationship between the stresses and hydraulical properties of the fractures. The roughness of a fracture surface governs the dilatation of the fracture and the displacement of the fracture surface under shear stress. The peak shear strength and hydraulic flow properties of fractures depend very much on the surface roughness. This report describes different methods and techniques used in the characterization of rock joint surfaces and their applications in rock mechanics

  10. Technology of Rock Destruction by Combined Explosion-Mechanical Load

    Directory of Open Access Journals (Sweden)

    Oleg M. Terentiev

    2017-10-01

    Full Text Available Background. Rock drilling is characterized by an energy capacity of more than 120 kWh/m3. This is due to the fact that about 90 % of the energy is expended on the “preparation” of rocks for destruction. This study proposes to combine explosive and mechanical loads to reduce specific energy consumption of rock destruction. Objective. The aim of the paper is energy effective technology development for rock destruction by combined explosive-mechanical loads. Methods. Analytical studies; regression analysis; math modeling; experimental research; technical and economic analysis. Results. Specific energy decreasing for explosive-mechanical rock drilling by 4–16 % was experimentally proved. Conclusions. As a result of the implementation of explosive-mechanical rock drilling on the created full-sized experimental device, the efficiency coefficient increased from 77 to 80 %.

  11. Geohydromechanical Processes in the Excavation Damaged Zone in Crystalline Rock, Rock Salt, and Indurated and Plastic Clays

    International Nuclear Information System (INIS)

    Tsang, Chin-Fu; Bernier, Frederic; Davies, Christophe

    2004-01-01

    The creation of an excavation disturbed zone or excavation damaged zone is expected around all man-made openings in geologic formations. Macro- and micro-fracturing, and in general a redistribution of in situ stresses and rearrangement of rock structures, will occur in this zone, resulting in drastic changes of permeability to flow, mainly through the fractures and cracks induced by excavation. Such an EDZ may have significant implications for the operation and long-term performance of an underground nuclear waste repository. Various issues of concern need to be evaluated, such as processes creating fractures in the excavation damaged zone, the degree of permeability increase, and the potential for sealing or healing (with permeability reduction) in the zone. In recent years, efforts along these lines have been made for a potential repository in four rock types-crystalline rock, salt, indurated clay, and plastic clay-and these efforts have involved field, laboratory, and theoretical studies. The present work involves a synthesis of the ideas and issues that emerged from presentations and discussions on EDZ in these four rock types at a CLUSTER Conference and Workshop held in Luxembourg in November, 2003. First, definitions of excavation disturbed and excavation damaged zones are proposed. Then, an approach is suggested for the synthesis and intercomparison of geohydromechanical processes in the EDZ for the four rock types (crystalline rock, salt, indurated clay, and plastic clay). Comparison tables of relevant processes, associated factors, and modeling and testing techniques are developed. A discussion of the general state-of-the-art and outstanding issues are also presented. A substantial bibliography of relevant papers on the subject is supplied at the end of the paper

  12. Measurement of diffusive properties of intact rock

    Energy Technology Data Exchange (ETDEWEB)

    Harvey, K B

    1996-12-01

    In the Postclosure Assessment of a Reference System for the Disposal of Canada`s Nuclear Fuel Waste (Goodwin et al. 1994) the disposal vault is assumed to be surrounded by a zone of intact rock, referred to as the `exclusion zone.` A sensitivity analysis of the relative effectiveness of the several engineered and natural barriers that contribute to the safety of the reference disposal system has shown that this zone of intact rock is the most effective of these barriers to the movement of radionuclides through the reference system. Peer review of the geosphere model used in the case study for the EIS (Environmental Impact Statement) of the Canadian Nuclear Fuel Waste Management Program has identified the need to quantify the properties of the intact rock surrounding the disposal vault that would control the transport of radionuclides by diffusion. The Postclosure Assessment also identified the need for appropriate values of the free water diffusion coefficient (D{sub o}) for {sup 129}1 and {sup 14}C. The measurement of rock resistivity allows the calculation of the Formation Factor for a rock This review describes the Formation Factor, diffusivity, permeability, and porosity, and how these properties might be measured or inferred for insitu rock under the conditions that apply to the intact rock surrounding a potential disposal vault. The importance of measuring the intrinsic diffusion coefficient (D{sup i}) of diffusing species under solution salinities simulating those of groundwaters is emphasised, and a method of measurement is described that is independent of the diffusing medium, and which would be appropriate for measurements made in chemically complex media such as groundwaters. (author). 95 refs., 4 tabs., 39 figs.

  13. Measurement of diffusive properties of intact rock

    International Nuclear Information System (INIS)

    Harvey, K.B.

    1996-12-01

    In the Postclosure Assessment of a Reference System for the Disposal of Canada's Nuclear Fuel Waste (Goodwin et al. 1994) the disposal vault is assumed to be surrounded by a zone of intact rock, referred to as the 'exclusion zone.' A sensitivity analysis of the relative effectiveness of the several engineered and natural barriers that contribute to the safety of the reference disposal system has shown that this zone of intact rock is the most effective of these barriers to the movement of radionuclides through the reference system. Peer review of the geosphere model used in the case study for the EIS (Environmental Impact Statement) of the Canadian Nuclear Fuel Waste Management Program has identified the need to quantify the properties of the intact rock surrounding the disposal vault that would control the transport of radionuclides by diffusion. The Postclosure Assessment also identified the need for appropriate values of the free water diffusion coefficient (D o ) for 129 1 and 14 C. The measurement of rock resistivity allows the calculation of the Formation Factor for a rock This review describes the Formation Factor, diffusivity, permeability, and porosity, and how these properties might be measured or inferred for insitu rock under the conditions that apply to the intact rock surrounding a potential disposal vault. The importance of measuring the intrinsic diffusion coefficient (D i ) of diffusing species under solution salinities simulating those of groundwaters is emphasised, and a method of measurement is described that is independent of the diffusing medium, and which would be appropriate for measurements made in chemically complex media such as groundwaters. (author). 95 refs., 4 tabs., 39 figs

  14. Diffusivity database (DDB) for major rocks. Database for the second progress report

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Haruo

    1999-10-01

    A database for diffusivity for a data setting of effective diffusion coefficients in rock matrices in the second progress report, was developed. In this database, 3 kinds of diffusion coefficients: effective diffusion coefficient (De), apparent diffusion coefficient (Da) and free water diffusion coefficient (Do) were treated. The database, based on literatures published between 1980 and 1998, was developed considering the following points. (1) Since Japanese geological environment is focused in the second progress report, data for diffusion are collected focused on Japanese major rocks. (2) Although 22 elements are considered to be important in performance assessment for geological disposal, all elements and aquatic tracers are treated in this database development considering general purpose. (3) Since limestone, which belongs to sedimentary rock, can become one of the natural resources and is inappropriate as a host rock, it is omitted in this database development. Rock was categorized into 4 kinds of rocks; acid crystalline rock, alkaline crystalline rock, sedimentary rock (argillaceous/tuffaceous rock) and sedimentary rock (psammitic rock/sandy stone) from the viewpoint of geology and mass transport. In addition, rocks around neutrality among crystalline rock were categorized into the alkaline crystalline rock in this database. The database is composed of sub-databases for 4 kinds of rocks. Furthermore, the sub-databases for 4 kinds of the rocks are composed of databases to individual elements, in which totally, 24 items such as species, rock name, diffusion coefficients (De, Da, Do), obtained conditions (method, porewater, pH, Eh, temperature, atmosphere, etc.), etc. are input. As a result of literature survey, for De values for acid crystalline rock, totally, 207 data for 18 elements and one tracer (hydrocarbon) have been reported and all data were for granitic rocks such as granite, granodiorite and biotitic granite. For alkaline crystalline rock, totally, 32

  15. Search for Magnetic Monopoles in Polar Volcanic Rocks

    DEFF Research Database (Denmark)

    Bendtz, K.; Milstead, D.; Hächler, H. -P.

    2013-01-01

    following the passage of igneous rock samples through a SQUID-based magnetometer. A total of 24.6 kg of rocks from various selected sites, among which 23.4 kg are mantle-derived rocks from the Arctic and Antarctic areas, was analyzed. No monopoles were found, and a 90% confidence level upper limit of 9.8 x...

  16. In situ fragmentation and rock particle sorting on arid hills

    Science.gov (United States)

    McGrath, Gavan S.; Nie, Zhengyao; Dyskin, Arcady; Byrd, Tia; Jenner, Rowan; Holbeche, Georgina; Hinz, Christoph

    2013-03-01

    Transport processes are often proposed to explain the sorting of rock particles on arid hillslopes, where mean rock particle size often decreases in the downslope direction. Here we show that in situ fragmentation of rock particles can also produce similar patterns. A total of 93,414 rock particles were digitized from 880 photographs of the surface of three mesa hills in the Great Sandy Desert, Australia. Rock particles were characterized by the projected Feret's diameter and circularity. Distance from the duricrust cap was found to be a more robust explanatory variable for diameter than the local hillslope gradient. Mean diameter decreased exponentially downslope, while the fractional area covered by rock particles decreased linearly. Rock particle diameters were distributed lognormally, with both the location and scale parameters decreasing approximately linearly downslope. Rock particle circularity distributions showed little change; only a slight shift in the mode to more circular particles was noted to occur downslope. A dynamic fragmentation model was used to assess whether in situ weathering alone could reproduce the observed downslope fining of diameters. Modeled and observed size distributions agreed well and both displayed a preferential loss of relatively large rock particles and an apparent approach to a terminal size distribution of the rocks downslope. We show this is consistent with a size effect in material strength, where large rocks are more susceptible to fatigue failure under stress than smaller rocks. In situ fragmentation therefore produces qualitatively similar patterns to those that would be expected to arise from selective transport.

  17. Rock Cycle. K-6 Science Curriculum.

    Science.gov (United States)

    Blueford, J. R.; And Others

    Rock Cycle is one of the units of a K-6 unified science curriculum program. The unit consists of four organizing sub-themes: (1) chemistry (introducing the topics of matter, elements, compounds, and chemical bonding); (2) characteristics (presenting hands-on activities with rocks and minerals); (3) minerals (emphasizing the aesthetic and economic…

  18. Geomechanical analysis of excavation-induced rock mass behavior of faulted Opalinus clay at the Mont Terri underground rock laboratory (Switzerland)

    International Nuclear Information System (INIS)

    Thoeny, R.

    2014-01-01

    Clay rock formations are potential host rocks for deep geological disposal of nuclear waste. However, they exhibit relatively low strength and brittle failure behaviour. Construction of underground openings in clay rocks may lead to the formation of an excavation damage zone (EDZ) in the near-field area of the tunnel. This has to be taken into account during risk assessment for waste-disposal facilities. To investigate the geomechanical processes associated with the rock mass response of faulted Opalinus Clay during tunnelling, a full-scale ‘mine-by’ experiment was carried out at the Mont Terri Underground Rock Laboratory (URL) in Switzerland. In the ‘mine-by’ experiment, fracture network characteristics within the experimental section were characterized prior to and after excavation by integrating structural data from geological mapping of the excavation surfaces and from four pre- and post-excavation boreholes.The displacements and deformations in the surrounding rock mass were measured using geo-technical instrumentation including borehole inclinometers, extensometers and deflectometers, together with high-resolution geodetic displacement measurements and laser scanning measurements on the excavation surfaces. Complementary data was gathered from structural and geophysical characterization of the surrounding rock mass. Geological and geophysical techniques were used to analyse the structural and kinematic relationships between the natural and excavation-induced fracture network surrounding the ‘mine-by’ experiment. Integrating the results from seismic refraction tomography, borehole logging, and tunnel surface mapping revealed that spatial variations in fault frequency along the tunnel axis alter the rock mass deformability and strength. Failure mechanisms, orientation and frequency of excavation-induced fractures are significantly influenced by tectonic faults. On the side walls, extensional fracturing tangential to the tunnel circumference was the

  19. Geomechanical analysis of excavation-induced rock mass behavior of faulted Opalinus clay at the Mont Terri underground rock laboratory (Switzerland)

    Energy Technology Data Exchange (ETDEWEB)

    Thoeny, R.

    2014-07-01

    Clay rock formations are potential host rocks for deep geological disposal of nuclear waste. However, they exhibit relatively low strength and brittle failure behaviour. Construction of underground openings in clay rocks may lead to the formation of an excavation damage zone (EDZ) in the near-field area of the tunnel. This has to be taken into account during risk assessment for waste-disposal facilities. To investigate the geomechanical processes associated with the rock mass response of faulted Opalinus Clay during tunnelling, a full-scale ‘mine-by’ experiment was carried out at the Mont Terri Underground Rock Laboratory (URL) in Switzerland. In the ‘mine-by’ experiment, fracture network characteristics within the experimental section were characterized prior to and after excavation by integrating structural data from geological mapping of the excavation surfaces and from four pre- and post-excavation boreholes.The displacements and deformations in the surrounding rock mass were measured using geo-technical instrumentation including borehole inclinometers, extensometers and deflectometers, together with high-resolution geodetic displacement measurements and laser scanning measurements on the excavation surfaces. Complementary data was gathered from structural and geophysical characterization of the surrounding rock mass. Geological and geophysical techniques were used to analyse the structural and kinematic relationships between the natural and excavation-induced fracture network surrounding the ‘mine-by’ experiment. Integrating the results from seismic refraction tomography, borehole logging, and tunnel surface mapping revealed that spatial variations in fault frequency along the tunnel axis alter the rock mass deformability and strength. Failure mechanisms, orientation and frequency of excavation-induced fractures are significantly influenced by tectonic faults. On the side walls, extensional fracturing tangential to the tunnel circumference was the

  20. Rock glaciers, Central Andes, Argentina, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — Primary rock glaciers are fed by avalanche chutes. At the El Salto rock glacier, surveys have been undertaken in order to determine the creep rate. Between 1981 and...

  1. Channelling of flow through fractures in rock

    International Nuclear Information System (INIS)

    Bourke, P.J.

    1987-05-01

    A method of mapping the channelling of flow in rock fractures formed by contacts between rock faces and of measuring the effective apertures of channels has been developed. Some typical results are given. (author)

  2. Compressible fluid flow through rocks of variable permeability

    International Nuclear Information System (INIS)

    Lin, W.

    1977-01-01

    The effectiveness of course-grained igneous rocks as shelters for burying radioactive waste can be assessed by determining the rock permeabilities at their in situ pressures and stresses. Analytical and numerical methods were used to solve differential equations of one-dimensional fluid flow through rocks with permeabilities from 10 4 to 1 nD. In these calculations, upstream and downstream reservoir volumes of 5, 50, and 500 cm 3 were used. The optimal size combinations of the two reservoirs were determined for measurements of permeability, stress, strain, acoustic velocity, and electrical conductivity on low-porosity, coarse-grained igneous rocks

  3. Study of gamma radiation between 0.1 and 1.0 MeV in the earth's atmosphere; Etude du rayonnement gamma entre 0,1 et 1 Mev dans l'atmosphere terrestre

    Energy Technology Data Exchange (ETDEWEB)

    Boclet, D [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1967-01-01

    The present work is devoted to some of the particular problems arising in the detection and localisation of sources of gamma radiation situated outside the earth's atmosphere. These weak sources can only be detected and localized if care is taken to eliminate gamma and particle radiations coming from other sources in the earth's atmosphere and in space. In order to separate the various sources of background noise, generally much stronger than the radiation under study, use is made of a directional detector whose characteristics are determined as described in the first part of the following report. The closest diffuse source considered is that constituted by the earth's atmosphere. Its detailed study will make it possible both to eliminate its effect when sources outside the earth are to be measured, and to predict the amount of secondary gamma radiation emitted by the same process in other celestial bodies, the moon in particular. This work considered in the 2. and 3. parts of the report. (author) [French] La presente etude est consacree a certains des problemes particuliers poses par la detection et la localisation des sources de rayonnement gamma situees hors de l'atmosphere terrestre. Ces sources faibles ne peuvent etre detectees et localisees que si l'on se protege des rayonnements gamma et particulaires provenant d'autres sources situees dans l'atmosphere terrestre et dans l'espace. Pour separer ces divers composants parasites, en general beaucoup plus intenses que le rayonnement a etudier, nous emploierons un detecteur directif dont nous determinons les caracteristiques dans la premiere partie de l'expose qui suit. La source diffuse la plus proche que nous considerons comme parasite est constituee par l'atmosphere terrestre. Son etude detaillee nous permettra d'une part de nous en proteger lorsque nous voudrons etudier les sources {gamma} extra-terrestres, d'autre part de prevoir le rayonnement gamma secondaire emis par le meme processus pour les autres corps

  4. Wing rock suppression using forebody vortex control

    Science.gov (United States)

    Ng, T. T.; Ong, L. Y.; Suarez, C. J.; Malcolm, G. N.

    1991-01-01

    Static and free-to-roll tests were conducted in a water tunnel with a configuration that consisted of a highly-slender forebody and 78-deg sweep delta wings. Flow visualization was performed and the roll angle histories were obtained. The fluid mechanisms governing the wing rock of this configuration were identified. Different means of suppressing wing rock by controlling the forebody vortices using small blowing jets were also explored. Steady blowing was found to be capable of suppressing wing rock, but significant vortex asymmetries had to be induced at the same time. On the other hand, alternating pulsed blowing on the left and right sides of the forebody was demonstrated to be potentially an effective means of suppressing wing rock and eliminating large asymmetric moments at high angles of attack.

  5. Dissecting the roles of ROCK isoforms in stress-induced cell detachment.

    Science.gov (United States)

    Shi, Jianjian; Surma, Michelle; Zhang, Lumin; Wei, Lei

    2013-05-15

    The homologous Rho kinases, ROCK1 and ROCK2, are involved in stress fiber assembly and cell adhesion and are assumed to be functionally redundant. Using mouse embryonic fibroblasts (MEFs) derived from ROCK1(-/-) and ROCK2(-/-) mice, we have recently reported that they play different roles in regulating doxorubicin-induced stress fiber disassembly and cell detachment: ROCK1 is involved in destabilizing the actin cytoskeleton and cell detachment, whereas ROCK2 is required for stabilizing the actin cytoskeleton and cell adhesion. Here, we present additional insights into the roles of ROCK1 and ROCK2 in regulating stress-induced impairment of cell-matrix and cell-cell adhesion. In response to doxorubicin, ROCK1(-/-) MEFs showed significant preservation of both focal adhesions and adherens junctions, while ROCK2(-/-) MEFs exhibited impaired focal adhesions but preserved adherens junctions compared with the wild-type MEFs. Additionally, inhibition of focal adhesion or adherens junction formations by chemical inhibitors abolished the anti-detachment effects of ROCK1 deletion. Finally, ROCK1(-/-) MEFs, but not ROCK2(-/-) MEFs, also exhibited preserved central stress fibers and reduced cell detachment in response to serum starvation. These results add new insights into a novel mechanism underlying the anti-detachment effects of ROCK1 deletion mediated by reduced peripheral actomyosin contraction and increased actin stabilization to promote cell-cell and cell-matrix adhesion. Our studies further support the differential roles of ROCK isoforms in regulating stress-induced loss of central stress fibers and focal adhesions as well as cell detachment.

  6. "DEAR ROCK, WHAT'S YOUR DESTINY? Ancient and modern uses of rocks in industry, building and art."

    Science.gov (United States)

    Pennesi, Daniela

    2015-04-01

    The project is for students of first grade of secondary school. The activity is a game, virtual or real of associations between rock and soil samples with their uses in industry, building and art. The students, alone or in a team, have to form pairs having available various samples of rocks, soils and building materials as bags of cement, tiles.. They have images of colonnades, staircases of famous churches, cave paintings and colors. The project is multidisciplinary. During the activity, the teachers of art and technical education are involved with and the teacher of sciences. The game can be used as an introduction for the rocks' classification. The inquiry in team, is a good way to learn the several uses of mineral resources.

  7. LSSVM-Based Rock Failure Criterion and Its Application in Numerical Simulation

    Directory of Open Access Journals (Sweden)

    Changxing Zhu

    2015-01-01

    Full Text Available A rock failure criterion is very important for the prediction of the failure of rocks or rock masses in rock mechanics and engineering. Least squares support vector machines (LSSVM are a powerful tool for addressing complex nonlinear problems. This paper describes a LSSVM-based rock failure criterion for analyzing the deformation of a circular tunnel under different in situ stresses without assuming a function form. First, LSSVM was used to represent the nonlinear relationship between the mechanical properties of rock and the failure behavior of the rock in order to construct a rock failure criterion based on experimental data. Then, this was used in a hypothetical numerical analysis of a circular tunnel to analyze the mechanical behavior of the rock mass surrounding the tunnel. The Mohr-Coulomb and Hoek-Brown failure criteria were also used to analyze the same case, and the results were compared; these clearly indicate that LSSVM can be used to establish a rock failure criterion and to predict the failure of a rock mass during excavation of a circular tunnel.

  8. Study of transfer reactions ({alpha},t), ({alpha},{sup 3}He) in the f-p shell: mechanism and spectroscopic use; Etude des reactions de transfert ({alpha},t), ({alpha},{sup 3}He) dans la couche f-p mecanisme et utilisation spectroscopique

    Energy Technology Data Exchange (ETDEWEB)

    Roussel, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1968-05-01

    We describe an experimental study of ({alpha},t), ({alpha},{sup 3}He) reactions at 44 MeV using a solid-state identifier, on the target-nuclei {sup 54}Fe and {sup 58,60,62,64}Ni. A critical study of optical model and of disturbed wave analysis has been performed. We show the complementarity of different transfer-reactions, the ambiguity of spectroscopic factors, the importance of the problem of the reaction mechanism. (author) [French] On decrit une etude experimentale des reactions ({alpha},t), ({alpha},{sup 3}He) a 44 MeV utilisant un systeme identificateur de particules sur les noyaux-cibles {sup 54}Fe et {sup 58,60,62,64}Ni. Une etude critique de modele optique et d'analyse en ondes deformees (D.W.B.A.) a ete entreprise. On montre la complementarite des differentes reactions de transfert, l'ambiguite des facteurs spectroscopiques, l'importance du probleme du mecanisme. (auteur)

  9. Study on investigation and evaluation methods of deep seated sedimentary rocks. Chemical weathering, pore water squeezing and relationships of physical properties of sedimentary rocks

    International Nuclear Information System (INIS)

    Oyama, Takahiro; Suzuki, Koichi

    2006-01-01

    Chemical weathering, porewater squeezing and physical properties for the sedimentary rocks were examined. Chemical weathering potential of rocks was described by the sulfur as a acceleration factor of weathering and carbonate contents as a neutralization factor of it. The carbonate contents in the rocks were measured accurately by the gas pressure measurement method. Pore water squeezing method was applied for the semi-hard sedimentary rocks (Opalinusclay). The chemical change of extracted pore water under high pressure conditions was estimated. Physical property of sedimentary rocks have relationship among the porosity and permeability and resistivity coefficient in the same rock types. It is possible to estimate the water permeability from the geophysical tests. (author)

  10. Study of cerenkov radiation. Production of {gamma} rays by electron accelerators; Etude du rayonnement de freinage. Production de rayons {gamma} par des accelerateurs d'electrons

    Energy Technology Data Exchange (ETDEWEB)

    Bernard, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1961-07-01

    This study is a critical comparison of the theories of Bremsstrahlung. Experimental results obtained by the production of {gamma} radiation with electron accelerators are compared to the theoretical results in order to estimate the extent to which the various theories are valid. (author) [French] Cette etude est une synthese des theories du rayonnement de freinage. Des resultats experimentaux, obtenus par la production de rayonnements {gamma} avec des accelerateurs d'electrons, sont compares aux resultats theoriques afin d'evaluer les domaines de validite des diverses theories. (auteur)

  11. Rocks and geology in the San Francisco Bay region

    Science.gov (United States)

    Stoffer, Philip W.

    2002-01-01

    The landscape of the San Francisco Bay region is host to a greater variety of rocks than most other regions in the United States. This introductory guide provides illustrated descriptions of 46 common and important varieties of igneous, sedimentary, and metamorphic rock found in the region. Rock types are described in context of their identification qualities, how they form, and where they occur in the region. The guide also provides discussion about of regional geology, plate tectonics, the rock cycle, the significance of the selected rock types in relation to both earth history and the impact of mineral resources on the development in the region. Maps and text also provide information where rocks, fossils, and geologic features can be visited on public lands or in association with public displays in regional museums, park visitor centers, and other public facilities.

  12. Strength and deformation properties of volcanic rocks in Iceland

    DEFF Research Database (Denmark)

    Foged, Niels Nielsen; Andreassen, Katrine Alling

    2016-01-01

    rock from Iceland has been the topic for rock mechanical studies carried out by Ice-landic guest students at the Department of Civil Engineering at the Technical University of Den-mark over a number of years in cooperation with University of Iceland, Vegagerðin (The Icelandic Road Directorate......) and Landsvirkjun (The National Power Company of Iceland). These projects involve engineering geological properties of volcanic rock in Iceland, rock mechanical testing and parameter evaluation. Upscaling to rock mass properties and modelling using Q- or GSI-methods have been studied by the students......Tunnelling work and preinvestigations for road traces require knowledge of the strength and de-formation properties of the rock material involved. This paper presents results related to tunnel-ling for Icelandic water power plants and road tunnels from a number of regions in Iceland. The volcanic...

  13. Thermal characteristics of rocks for high-level waste repository

    International Nuclear Information System (INIS)

    Shimooka, Kenji; Ishizaki, Kanjiro; Okamoto, Masamichi; Kumata, Masahiro; Araki, Kunio; Amano, Hiroshi

    1980-12-01

    Heat released by the radioactive decay of high-level waste in an underground repository causes a long term thermal disturbance in the surrounding rock mass. Several rocks constituting geological formations in Japan were gathered and specific heat, thermal conductivity, thermal expansion coefficient and compressive strength were measured. Thermal analysis and chemical analysis were also carried out. It was found that volcanic rocks, i.e. Andesite and Basalt had the most favorable thermal characteristics up to around 1000 0 C and plutonic rock, i.e. Granite had also favorable characteristics under 573 0 C, transition temperature of quartz. Other igneous rocks, i.e. Rhyolite and Propylite had a problem of decomposition at around 500 0 C. Sedimentary rocks, i.e. Zeolite, Tuff, Sandstone and Diatomite were less favorable because of their decomposition, low thermal conductivity and large thermal expansion coefficient. (author)

  14. The History of Rock Art Research

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. The History of Rock Art Research. Rock art in South India was discovered as early as 1891.The earliest discovery of petroglyphs on the Koppagallu hill in Bellary district was made by Fred Fawcett (1892) who with the assistance of H.T.Knox and Robert Sewell ...

  15. Contribution to the study of samarium-151 excited levels; Contribution a l'etude des niveaux excites du samarium-151

    Energy Technology Data Exchange (ETDEWEB)

    Locard, P [Commissariat a l' Energie Atomique, Centre d' Etudes Nucleaires de Grenoble, 38 (France)

    1967-07-01

    The nucleus of {sup 151}Sm, which has 89 neutrons, happens to be on the lower edge of the deformed nuclei of region II. Therefore, the study of its levels is very interesting for the verification of the goodness of the collective models for deformed nuclei when the deformation is small (we introduce these models in the first chapter). {sup 151}Sm has often been studied, but the direct gamma spectrum measured with a lithium drift-germanium detector (chapter 3) shows many high energy transitions which did not appear in the previous level schemes. In order to settle these transitions, we have undertaken gamma-gamma coincidence spectra (as well as sum-coincidence spectra) experiments with a scintillation spectrometer designed in our laboratory (chapter 2). The investigation of the intensities of these coincidences leads us to modify the last proposed level schemes: we suppress the levels at 405,5 and 650 keV, we add levels at 245,6 - 306,6 - 522 - 952 and 962 keV. We have also verified the multipolarities of the main transitions and measured the half-lives of a few levels (chapter 3) (we find a half-life of 1.1 {+-} 0.5 nanosecond for the level at 167,7 keV). In chapter 4, we compare our results to the predictions of the models described in chapter 1. (author) [French] Le noyau de {sup 151}Sm, qui possede 89 neutrons, se trouve a la limite inferieure des noyaux deformes de la region II. L'etude de ses niveaux excites est donc d'un interet tout particulier pour la verification de la validite des differents modeles collectifs pour les noyaux deformes, lorsque la deformation est petite (nous introduisons ces modeles dans un premier chapitre). Le {sup 151}Sm a deja fait l'objet de nombreuses etudes, mais le spectre gamma direct fait avec une jonction de germanium compense au lithium (chapitre 3), nous a montre l'existence d'un grand nombre de transitions de hautes energies qui ne sont pas placees dans les schemas proposes jusqu'a ce jour. Pour preciser la place de ces

  16. Depositional environment and source rock potential of Cenomanian and Turonian sedimentary rocks of the Tarfaya Basin, Southwest Morocco

    Energy Technology Data Exchange (ETDEWEB)

    Ghassal, B.I.; Littke, R.; Sachse, V.; Sindern, S.; Schwarzbauer, J.

    2016-07-01

    Detailed organic and inorganic geochemical analyses were used to assess the depositional environment and source rock potential of the Cenomanian and Turonian oil shale deposits in the Tarfaya Basin. This study is based on core samples from the Tarfaya Sondage-4 well that penetrated over 300m of Mid Cretaceous organic matter-rich deposits. A total of 242 samples were analyzed for total organic and inorganic carbon and selected samples for total sulfur and major elements as well as for organic petrology, Rock-Eval pyrolysis, Curie-Point-pyrolysis-gaschromatography-Mass-Spectrometry and molecular geochemistry of solvent extracts. Based on major elements the lower Cenomanian differs from the other intervals by higher silicate and lower carbonate contents. Moreover, the molecular geochemistry suggests anoxic bottom marine water conditions during the Cenomanian-Turonian Boundary Event (CTBE; Oceanic Anoxic Event 2: OAE2). As a proxy for the Sorg/Corg ratio, the ratio total thiophenes/total benzenes compounds was calculated from pyrolysate compositions. The results suggest that Sorg/ Corg is low in the lower Cenomanian, moderate in the upper Cenomanian, very high in the CTBE (CenomanianTuronian Boundary Event) and high in the Turonian samples. Rock-Eval data reveal that the lower Cenomanian is a moderately organic carbon-rich source rock with good potential to generate oil and gas upon thermal maturation. On the other hand, the samples from the upper Cenomanian to Turonian exhibit higher organic carbon content and can be classified as oil-prone source rocks. Based on Tmax data, all rocks are thermally immature. The microscopic investigations suggest dominance of submicroscopic organic matter in all samples and different contents of bituminite and alginite. The lower Cenomanian samples have little visible organic matter and no bituminite. The upper Cenomanian and CTBE samples are poor in bituminite and have rare visible organic matter, whereas the Turonian samples change

  17. Cenozoic volcanic rocks of Saudi Arabia

    Science.gov (United States)

    Coleman, R.G.; Gregory, R.T.; Brown, G.F.

    2016-01-01

    The Cenozoic volcanic rocks of Saudi Arabia cover about 90,000 km2, one of the largest areas of alkali olivine basalt in the world. These volcanic rocks are in 13 separate fields near the eastern coast of the Red Sea and in the western Arabian Peninsula highlands from Syria southward to the Yemen Arab Republic.

  18. Rock Moved by Mars Lander Arm, Stereo View

    Science.gov (United States)

    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.

  19. Solidification of residual fission-product solutions; laboratory studies; Solidification de solutions residuaires concentrees de produits de fission: etudes de laboratoire

    Energy Technology Data Exchange (ETDEWEB)

    Boniaud, R; Cohen, P; Sombret, C [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1961-07-01

    This paper describes the results obtained, at laboratory scale, during the study of the incorporation of fission products into glasses and synthetic micas. The rate of leaching of fission products from the glass and their volatility during firing were measured. A hot cell was built to complete these results. (author) [French] Ce rapport resume le resultat des etudes faites en laboratoire (activite de l'ordre du millicurie) sur l'incorporation des produits de fission dans des verres et micas synthetiques. On a mesure le taux de lixiviation des produits de fission et leur volatilisation au cours de la cuisson. Une cellule chaude a ete installee pour completer ces resultats au moyen d'essais realises avec une activite superieure. (auteur)

  20. Dynamic elastic moduli of rocks under pressure

    Energy Technology Data Exchange (ETDEWEB)

    Schock, R N [Lawrence Radiation Laboratory, University of California, Livermore, CA (United States)

    1970-05-01

    Elastic moduli are determined as a function of confining pressure to 10 kb on rocks in which Plowshare shots are to be fired. Numerical simulation codes require accurate information on the mechanical response of the rock medium to various stress levels in order to predict cavity dimensions. The theoretical treatment of small strains in an elastic medium relates the propagation velocity of compressional and shear waves to the elastic moduli. Velocity measurements can provide, as unique code input data, the rigidity modulus, Poisson' ratio and the shear wave velocity, as well as providing checks on independent determinations of the other moduli. Velocities are determined using pulsed electro-mechanical transducers and measuring the time-of-flight in the rock specimen. A resonant frequency of 1 MHz is used to insure that the wavelength exceeds the average grain dimension and is subject to bulk rock properties. Data obtained on a variety of rock types are presented and analyzed. These data are discussed in terms of their relationship to moduli measured by static methods as well as the effect of anisotropy, porosity, and fractures. In general, fractured rocks with incipient cracks show large increases in velocity and moduli in the first 1 to 2 kb of compression as a result of the closing of these voids. After this, the velocities increase much more slowly. Dynamic moduli for these rocks are often 10% higher than corresponding static moduli at low pressure, but this difference decreases as the voids are closed until the moduli agree within experimental error. The discrepancy at low pressure is a result of the elastic energy in the wave pulse being propagated around cracks, with little effect on propagation velocity averaged over the entire specimen. (author)

  1. Dynamic elastic moduli of rocks under pressure

    International Nuclear Information System (INIS)

    Schock, R.N.

    1970-01-01

    Elastic moduli are determined as a function of confining pressure to 10 kb on rocks in which Plowshare shots are to be fired. Numerical simulation codes require accurate information on the mechanical response of the rock medium to various stress levels in order to predict cavity dimensions. The theoretical treatment of small strains in an elastic medium relates the propagation velocity of compressional and shear waves to the elastic moduli. Velocity measurements can provide, as unique code input data, the rigidity modulus, Poisson' ratio and the shear wave velocity, as well as providing checks on independent determinations of the other moduli. Velocities are determined using pulsed electro-mechanical transducers and measuring the time-of-flight in the rock specimen. A resonant frequency of 1 MHz is used to insure that the wavelength exceeds the average grain dimension and is subject to bulk rock properties. Data obtained on a variety of rock types are presented and analyzed. These data are discussed in terms of their relationship to moduli measured by static methods as well as the effect of anisotropy, porosity, and fractures. In general, fractured rocks with incipient cracks show large increases in velocity and moduli in the first 1 to 2 kb of compression as a result of the closing of these voids. After this, the velocities increase much more slowly. Dynamic moduli for these rocks are often 10% higher than corresponding static moduli at low pressure, but this difference decreases as the voids are closed until the moduli agree within experimental error. The discrepancy at low pressure is a result of the elastic energy in the wave pulse being propagated around cracks, with little effect on propagation velocity averaged over the entire specimen. (author)

  2. Rock Slope Design Criteria : Executive Summary Report

    Science.gov (United States)

    2010-06-01

    Based on the stratigraphy and the type of slope stability problems, the flat lying, Paleozoic age, sedimentary rocks of Ohio were divided into three design units: 1) competent rock design unit consisting of sandstones, limestones, and siltstones that...

  3. ROCK: The readout controller for the KLOE experiment

    International Nuclear Information System (INIS)

    Aloisio, A.; Cavaliere, S.; Cevenini, F.; Volpe, D. della; Merola, L.; Fiore, D.J.; Parascandolo, P.

    1996-01-01

    A read-out controller (ROCK) has been developed for the Data Acquisition System of the KLOE High Energy Physics experiment, based in Frascati, Italy. The ROCK performs data acquisition in an event-driven fashion on the AUXbus, a custom high speed parallel bus. The AUXbus's main features are data cycles labeled by event number, sparse data scan operations and an asynchronous protocol optimized to achieve data rates up to 15 MHz. On a standard VMEbus, the ROCK allows for data snooping and real-time performance monitoring, without additional overhead on data acquisition. ROCK boards can be linked together via a custom cable bus (Cbus) to build a complex DAQ subsystem. The ROCK board has been designed around three 4.2 K gate XILINX FPGAs. Dual port FIFO banks are used to decouple the asynchronous buses. A preliminary version of the board is presented and test results are briefly discussed

  4. Multiparameter Monitoring and Prevention of Fault-Slip Rock Burst

    OpenAIRE

    Hu, Shan-chao; Tan, Yun-liang; Ning, Jian-guo; Guo, Wei-Yao; Liu, Xue-sheng

    2017-01-01

    Fault-slip rock burst is one type of the tectonic rock burst during mining. A detailed understanding of the precursory information of fault-slip rock burst and implementation of monitoring and early warning systems, as well as pressure relief measures, are essential to safety production in deep mines. This paper first establishes a mechanical model of stick-slip instability in fault-slip rock bursts and then reveals the failure characteristics of the instability. Then, change rule of mining-i...

  5. Thermo-mechanical ratcheting in jointed rock masses

    KAUST Repository

    Pasten, C.

    2015-09-01

    Thermo-mechanical coupling takes place in jointed rock masses subjected to large thermal oscillations. Examples range from exposed surfaces under daily and seasonal thermal fluctuations to subsurface rock masses affected by engineered systems such as geothermal operations. Experimental, numerical and analytical results show that thermo-mechanical coupling can lead to wedging and ratcheting mechanisms that result in deformation accumulation when the rock mass is subjected to a biased static-force condition. Analytical and numerical models help in identifying the parameter domain where thermo-mechanical ratcheting can take place.

  6. Radon and rock bursts in deep mines

    International Nuclear Information System (INIS)

    Bulashevich, Yu.P.; Utkin, V.I.; Yurkov, A.K.; Nikolaev, V.V.

    1996-01-01

    Variation fields of radon concentration in time to ascertain stress-strain state of the North Ural bauxite mines have been studied. It is shown that dynamic changes in the stress-strain state of the rocks prior to the rock burst bring about variations in radon concentration in the observation wells. Depending on mutual positioning of the observation points and the rock burst epicenter, the above-mentioned variations differ in principle, reduction of radon concentration in the near zone and its increase in the far zone are observed [ru

  7. Thermo-mechanical ratcheting in jointed rock masses

    KAUST Repository

    Pasten, C.; Garcí a, M.; Santamarina, Carlos

    2015-01-01

    Thermo-mechanical coupling takes place in jointed rock masses subjected to large thermal oscillations. Examples range from exposed surfaces under daily and seasonal thermal fluctuations to subsurface rock masses affected by engineered systems such as geothermal operations. Experimental, numerical and analytical results show that thermo-mechanical coupling can lead to wedging and ratcheting mechanisms that result in deformation accumulation when the rock mass is subjected to a biased static-force condition. Analytical and numerical models help in identifying the parameter domain where thermo-mechanical ratcheting can take place.

  8. Acoustics in rock and pop music halls

    DEFF Research Database (Denmark)

    Larsen, Niels Werner; Thompson, Eric Robert; Gade, Anders Christian

    2007-01-01

    The existing body of literature regarding the acoustic design of concert halls has focused almost exclusively on classical music, although there are many more performances of rhythmic music, including rock and pop. Objective measurements were made of the acoustics of twenty rock music venues...... in Denmark and a questionnaire was used in a subjective assessment of those venues with professional rock musicians and sound engineers. Correlations between the objective and subjective results lead, among others, to a recommendation for reverberation time as a function of hall volume. Since the bass...

  9. Heat production / host rock compatibility; Waermeentwicklung / Gesteinsvertraeglichkeit

    Energy Technology Data Exchange (ETDEWEB)

    Meleshyn, A.; Weyand, T.; Bracke, G.; Kull, H.; Wieczorek, K.

    2016-05-15

    For the final high-level radioactive waste repository potential host rock formations are either rock salt or clays (Kristallin). Heat generating waste (decay heat of the radioactive materials) can be absorbed by the host rock. The effect of temperature increase on the thermal conductivity, the thermal expansion and the mechanical properties of salt, Kristallin, clays and argilliferous geotechnical barriers are described. Further issues of the report are the mineralogical behavior, phase transformations, hydrochemistry, microbial processes, gas formation, thermochemical processes and gas ingress. Recommendations for further research are summarized.

  10. Analysis of volcano rocks by Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Sitek, J.; Dekan, J.

    2012-01-01

    In this work we have analysed the basalt rock from Mount Ba tur volcano situated on the Island of Bali in Indonesia.We compared our results with composition of basalt rocks from some other places on the Earth. (authors)

  11. Acute and long term outcomes of catheter ablation using remote magnetic navigation for the treatment of electrical storm in patients with severe ischemic heart failure

    DEFF Research Database (Denmark)

    Jin, Qi; Jacobsen, Peter Karl; Pehrson, Steen

    2015-01-01

    BACKGROUND: Catheter ablation with remote magnetic navigation (RMN) can offer some advantages compared to manual techniques. However, the relevant clinical evidence for how RMN-guided ablation affects electrical storm (ES) due to ventricular tachycardia (VT) in patients with severe ischemic heart......-guided catheter ablation can prevent VT recurrence and significantly reduce ICD shocks, suggesting that this strategy can be used as an alternative therapy for VT storm in SIHF patients with ICDs....

  12. Dissecting the roles of ROCK isoforms in stress-induced cell detachment

    OpenAIRE

    Shi, Jianjian; Surma, Michelle; Zhang, Lumin; Wei, Lei

    2013-01-01

    The homologous Rho kinases, ROCK1 and ROCK2, are involved in stress fiber assembly and cell adhesion and are assumed to be functionally redundant. Using mouse embryonic fibroblasts (MEFs) derived from ROCK1 ?/? and ROCK2?/? mice, we have recently reported that they play different roles in regulating doxorubicin-induced stress fiber disassembly and cell detachment: ROCK1 is involved in destabilizing the actin cytoskeleton and cell detachment, whereas ROCK2 is required for stabilizing the actin...

  13. Application of Confined Blasting in Water-Filled Deep Holes to Control Strong Rock Pressure in Hard Rock Mines

    Directory of Open Access Journals (Sweden)

    Jingxuan Yang

    2017-11-01

    Full Text Available In extra-thick coal seams, mining operations can lead to large-scale disturbances, complex overburden structures, and frequent and strong strata behavior in the stope, which are serious threats to mine safety. This study analyzed the overburden structure and strata behavior and proposed the technique of confined blasting in water-filled deep holes as a measure to prevent strong rock pressure. It found that there are two primary reasons for the high effectiveness of the proposed technique in presplitting hard coal and rock. First, the fracture water enables much more efficient transfer of dynamic load due to its incompressibility. Second, the subsequent expansion of water can further split the rock by compression. A mechanical model was used to reveal how the process of confined blasting in water-filled deep holes presplit roof. Moreover, practical implementation of this technique was found to improve the structure of hard, thick roof and prevent strong rock pressure, demonstrating its effectiveness in roof control.

  14. Experimental investigation of incipient shear failure in foliated rock

    NARCIS (Netherlands)

    Ikari, Matt J.; Niemeijer, André R.; Marone, Chris

    It has long been known that rock fabric plays a key role in dictating rock strength and rheology throughout Earth's crust; however the processes and conditions under which rock fabric impacts brittle failure and frictional strength are still under investigation. Here, we report on laboratory

  15. Engineering assessment of inactive uranium mill tailings: Slick Rock sites, Slick Rock, Colorado

    International Nuclear Information System (INIS)

    1981-09-01

    Ford, Bacon and Davis Utah, Inc., has reevaluated the Slick Rock sites in order to revise the October 1977 engineering radioactive uranium mill tailings at Slick Rock, Colorado. This engineering assessment has included the preparation of topographic maps, the performance of core drillings and radiometric measurements sufficient to determine areas and volumes of tailings and radiation exposures of individuals and nearby populations, the investigations of site hydrology and meteorology, and the evaluation and costing of alternative corrective actions. Radon gas released from the 387,000 tons of tailings at the Slick Rock sites constitutes the most significant environmental impact, although windblown tailings and external gamma radiation also are factors. The five alternative actions presented in this engineering assessment include millsite decontamination with the addition of 3 m of stabilization cover material, consolidation of the piles, and removal of the tailings to remote disposal sites and decontamination of the tailings sites. Cost estimates for the five options range from about $6,800,000 for stabilization in-place, to about $11,000,000 for disposal at a distance of about 6.5 mi. Three principal alternatives for the reprocessing of the Slick Rock tailings were examined: heap leaching; treatment at an existing mill; and reprocessing at a new conventional mill constructed for tailings reprocessing. The cost of the uranium recovered would be over $800/lb of U 3 O 8 whether by conventional or heap leach plant processes. The spot market price for uranium was $25/lb early in 1981. Therefore, reprocessing the tailings for uranium recovery is not economically attractive at present, nor for the foreseeable future

  16. Engineering assessment of inactive uranium mill tailings: Slick Rock sites, Slick Rock, Colorado

    Energy Technology Data Exchange (ETDEWEB)

    None

    1981-09-01

    Ford, Bacon and Davis Utah, Inc., has reevaluated the Slick Rock sites in order to revise the October 1977 engineering radioactive uranium mill tailings at Slick Rock, Colorado. This engineering assessment has included the preparation of topographic maps, the performance of core drillings and radiometric measurements sufficient to determine areas and volumes of tailings and radiation exposures of individuals and nearby populations, the investigations of site hydrology and meteorology, and the evaluation and costing of alternative corrective actions. Radon gas released from the 387,000 tons of tailings at the Slick Rock sites constitutes the most significant environmental impact, although windblown tailings and external gamma radiation also are factors. The five alternative actions presented in this engineering assessment include millsite decontamination with the addition of 3 m of stabilization cover material, consolidation of the piles, and removal of the tailings to remote disposal sites and decontamination of the tailings sites. Cost estimates for the five options range from about $6,800,000 for stabilization in-place, to about $11,000,000 for disposal at a distance of about 6.5 mi. Three principal alternatives for the reprocessing of the Slick Rock tailings were examined: heap leaching; treatment at an existing mill; and reprocessing at a new conventional mill constructed for tailings reprocessing. The cost of the uranium recovered would be over $800/lb of U/sub 3/O/sub 8/ whether by conventional or heap leach plant processes. The spot market price for uranium was $25/lb early in 1981. Therefore, reprocessing the tailings for uranium recovery is not economically attractive at present, nor for the foreseeable future.

  17. Historical rock falls in Yosemite National Park, California (1857-2011)

    Science.gov (United States)

    Stock, Greg M.; Collins, Brian D.; Santaniello, David J.; Zimmer, Valerie L.; Wieczorek, Gerald F.; Snyder, James B.

    2013-01-01

    Inventories of rock falls and other types of landslides are valuable tools for improving understanding of these events. For example, detailed information on rock falls is critical for identifying mechanisms that trigger rock falls, for quantifying the susceptibility of different cliffs to rock falls, and for developing magnitude-frequency relations. Further, inventories can assist in quantifying the relative hazard and risk posed by these events over both short and long time scales. This report describes and presents the accompanying rock fall inventory database for Yosemite National Park, California. The inventory database documents 925 events spanning the period 1857–2011. Rock falls, rock slides, and other forms of slope movement represent a serious natural hazard in Yosemite National Park. Rock-fall hazard and risk are particularly relevant in Yosemite Valley, where glacially steepened granitic cliffs approach 1 km in height and where the majority of the approximately 4 million yearly visitors to the park congregate. In addition to damaging roads, trails, and other facilities, rock falls and other slope movement events have killed 15 people and injured at least 85 people in the park since the first documented rock fall in 1857. The accompanying report describes each of the organizational categories in the database, including event location, type of slope movement, date, volume, relative size, probable trigger, impact to humans, narrative description, references, and environmental conditions. The inventory database itself is contained in a Microsoft Excel spreadsheet (Yosemite_rock_fall_database_1857-2011.xlsx). Narrative descriptions of events are contained in the database, but are also provided in a more readable Adobe portable document format (pdf) file (Yosemite_rock_fall_database_narratives_1857-2011.pdf) available for download separate from the database.

  18. Study of a photomultiplier for the measurement of low light flows by photon counting; Etude d'un photomultiplicateur en vue de la mesure des faibles flux lumineux par comptage de photons

    Energy Technology Data Exchange (ETDEWEB)

    Haye, Kleber

    1964-03-20

    After a recall of the history of the discovery and use of the photoemission effect, a presentation of the main characteristics of photomultipliers, a discussion of performance and weaknesses of electron multiplier-based cells, this research thesis addresses the study of low light flows. The author tried to determine whether it was possible, at ambient temperature, to reduce the influence of the thermoelectric effect. In order to do so, he made a detailed study of the amplitude spectrum of pulses of photoelectric origin. In order to analyse the influence of temperature of photomultiplier characteristics, he studied, with respect to temperature, the variation of the counting rate corresponding to darkness, the variation of pulse amplitude spectrum, and relative variations of the quantum efficiency for various wavelengths. In parallel with the study by counting, a study has been performed by using the well known mean current measurement [French] Si l'on veut etudier de faibles flux lumineux, c'est surtout l'effet thermoelectronique qui limite a temperature ambiante le domaine possible des mesures. Les electrons qui arrivent en effet a quitter la photocathode ou les dynodes donnent naissance a des groupes supplementaires d'electrons venant s'ajouter a ceux causes par effet photoelectrique. En utilisant une methode de mesure par comptage des groupes d'electrons, nous nous sommes attaches a determiner s'il etait possible a temperature ordinaire de reduire 1'influence de l'effet thermoelectronique. Pour cela, nous avons fait une etude detaillee du spectre d'amplitude des impulsions d'origine photoelectrique. Toutefois, la solution la plus efficace pour combattre l'effet thermoelectronique etant le refroidissement, nous avons essaye d'analyser l'influence de la temperature sur les caracteristiques du photomultiplicateur. Nous avons ainsi etudie en fonction de la temperature la variation du taux de comptage correspondant a l'obscurite, la variation du spectre d

  19. Migmatites and migmatite-like rocks of Olkiluoto

    International Nuclear Information System (INIS)

    Kaerki, A.

    2015-02-01

    Bedrock of the Olkiluoto Island in the western end of the Palaeoproterozoic Svecofennian Accretionary Arc Complex, SW Finland is composed of high-grade metamorphic pelites, arenites and intermediate, arc type metavolcanic rocks intruded by granodioritic to tonalitic plutonic rocks. Regional metamorphism culminated with voluminous migmatization in the temperature of 660 - 700 deg C and relatively low pressure of about 3.5 - 4 kbar. The end result of polyphase metamorphism and deformation is a metamorphic rock succession composed of diverse migmatite rocks, metatexites and diatexites. Metatexites are migmatites in which several, discrete components can be detected, and in which the paleosome with some pre-partial-melting textures is identifiable. Diatexites are more advanced migmatites in which the pre-migmatization structures are often totally destroyed and the rock is dominated by different neosome components meaning leucosome, melanosome or mesosome. Based on the migmatite structures the metatexites of Olkiluoto have been classified into six subgroups. Dike-structured metatexites are composed of well preserved paleosome intruded by one single set of narrow, subparallel leucosome dikes which cover ca. 5 - 10 % of the whole rock volume. Net-structure is composed of a network of narrow leucosome dikes which show a reticulated structure in a plane section and cover less than 30 % of the whole rock volume. Breccia-structure is composed of angular or rounded paleosome blocks surrounded by moderate amount of leucosome. Patch-structure is composed of irregular leucosome patches which intruded the well preserved paleosome and compose typically 20 - 70 % of the rock volume. Layer-structure is characterized by more or less regular leucosome dikes sub-parallel to the foliation of the well preserved paleosome. Vein-structured metatexites and also diatexites include a set of pipe-like, longish leucosome veins most probably generated by synchronous melting and deformation

  20. Migmatites and migmatite-like rocks of Olkiluoto

    Energy Technology Data Exchange (ETDEWEB)

    Kaerki, A. [Kivitieto Oy, Oulu (Finland)

    2015-02-15

    Bedrock of the Olkiluoto Island in the western end of the Palaeoproterozoic Svecofennian Accretionary Arc Complex, SW Finland is composed of high-grade metamorphic pelites, arenites and intermediate, arc type metavolcanic rocks intruded by granodioritic to tonalitic plutonic rocks. Regional metamorphism culminated with voluminous migmatization in the temperature of 660 - 700 deg C and relatively low pressure of about 3.5 - 4 kbar. The end result of polyphase metamorphism and deformation is a metamorphic rock succession composed of diverse migmatite rocks, metatexites and diatexites. Metatexites are migmatites in which several, discrete components can be detected, and in which the paleosome with some pre-partial-melting textures is identifiable. Diatexites are more advanced migmatites in which the pre-migmatization structures are often totally destroyed and the rock is dominated by different neosome components meaning leucosome, melanosome or mesosome. Based on the migmatite structures the metatexites of Olkiluoto have been classified into six subgroups. Dike-structured metatexites are composed of well preserved paleosome intruded by one single set of narrow, subparallel leucosome dikes which cover ca. 5 - 10 % of the whole rock volume. Net-structure is composed of a network of narrow leucosome dikes which show a reticulated structure in a plane section and cover less than 30 % of the whole rock volume. Breccia-structure is composed of angular or rounded paleosome blocks surrounded by moderate amount of leucosome. Patch-structure is composed of irregular leucosome patches which intruded the well preserved paleosome and compose typically 20 - 70 % of the rock volume. Layer-structure is characterized by more or less regular leucosome dikes sub-parallel to the foliation of the well preserved paleosome. Vein-structured metatexites and also diatexites include a set of pipe-like, longish leucosome veins most probably generated by synchronous melting and deformation

  1. Rainfall as primary driver of discharge and solute export from rock glaciers: The Col d'Olen Rock Glacier in the NW Italian Alps.

    Science.gov (United States)

    Colombo, Nicola; Gruber, Stephan; Martin, Maria; Malandrino, Mery; Magnani, Andrea; Godone, Danilo; Freppaz, Michele; Fratianni, Simona; Salerno, Franco

    2018-10-15

    Three hypotheses exist to explain how meteorological variables drive the amount and concentration of solute-enriched water from rock glaciers: (1) Warm periods cause increased subsurface ice melt, which releases solutes; (2) rain periods and the melt of long-lasting snow enhance dilution of rock-glacier outflows; and (3) percolation of rain through rock glaciers facilitates the export of solutes, causing an opposite effect as that described in hypothesis (2). This lack of detailed understanding likely exists because suitable studies of meteorological variables, hydrologic processes and chemical characteristics of water bodies downstream from rock glaciers are unavailable. In this study, a rock-glacier pond in the North-Western Italian Alps was studied on a weekly basis for the ice-free seasons 2014 and 2015 by observing the meteorological variables (air temperature, snowmelt, rainfall) assumed to drive the export of solute-enriched waters from the rock glacier and the hydrochemical response of the pond (water temperature as a proxy of rock-glacier discharge, stable water isotopes, major ions and selected trace elements). An intra-seasonal pattern of increasing solute export associated with higher rock-glacier discharge was found. Specifically, rainfall, after the winter snowpack depletion and prolonged periods of atmospheric temperature above 0 °C, was found to be the primary driver of solute export from the rock glacier during the ice-free season. This occurs likely through the flushing of isotopically- and geochemically-enriched icemelt, causing concomitant increases in the rock-glacier discharge and the solute export (SO 4 2- , Mg 2+ , Ca 2+ , Ni, Mn, Co). Moreover, flushing of microbially-active sediments can cause increases in NO 3 - export. Copyright © 2018 Elsevier B.V. All rights reserved.

  2. Basaltic rocks analyzed by the Spirit rover in Gusev crater

    Science.gov (United States)

    McSween, H.Y.; Arvidson, R. E.; Bell, J.F.; Blaney, D.; Cabrol, N.A.; Christensen, P.R.; Clark, B. C.; Crisp, J.A.; Crumpler, L.S.; Des Marias, D.J.; Farmer, J.D.; Gellert, Ralf; Ghosh, A.; Gorevan, S.; Graff, T.; Grant, J.; Haskin, L.A.; Herkenhoff, K. E.; Johnson, J. R.; Jolliff, B.L.; Klingelhoefer, G.; Knudson, A.T.; McLennan, S.; Milam, K.A.; Moersch, J.E.; Morris, R.V.; Rieder, R.; Ruff, S.W.; De Souza, P.A.; Squyres, S. W.; Wanke, H.; Wang, A.; Wyatt, M.B.; Yen, A.; Zipfel, J.

    2004-01-01

    The Spirit landing site in Gusev Crater on Mars contains dark, fine-grained, vesicular rocks interpreted as lavas. Pancam and Mini-Thermal Emission Spectrometer (Mini-TES) spectra suggest that all of these rocks are similar but have variable coatings and dust mantles. Magnified images of brushed and abraded rock surfaces show alteration rinds and veins. Rock interiors contain ???25% megacrysts. Chemical analyses of rocks by the Alpha Particle X-ray Spectrometer are consistent with picritic basalts, containing normative olivine, pyroxenes, plagioclase, and accessory FeTi oxides. Mo??ssbauer, Pancam, and Mini-TES spectra confirm the presence of olivine, magnetite, and probably pyroxene. These basalts extend the known range of rock compositions composing the martian crust.

  3. Contribution to the development of a gamma radiation camera for use in scintigraphy; Contribution a l'etude et a la realisation d'une camera a rayonnement gamma en vue d'une application a la scintigraphie

    Energy Technology Data Exchange (ETDEWEB)

    Felix, J [Commissariat a l' Energie Atomique, Cadarache (France). Centre d' Etudes Nucleaires

    1969-10-01

    This report constitutes an attempt to study systematically the properties of the detection head of a multichannel collimating grid camera. The object has been to show the disadvantages of present equipment, and to propose possible solutions for overcoming them: firstly by improving the methods used for collecting data, and the performances of the equipment doing the collecting; secondly by devising methods for processing the data so as to reduce image distortion and, first of all, the astigmatism due to the collimator. The first part deals with the study of the formation of the image by means of the collimating grid, the second with the examination of many systems which could be used for acquiring data. The last part summarizes the experiments carried out and proposes an experimental programme for the development of a prototype. (author) [French] Ce rapport constitue une tentative d'etude systematique des proprietes de la tete de detection d'une camera a grille collimatrice multicanal. Le but de cette etude est de souligner les inconvenients des dispositifs actuels et d'esquisser des solutions propres a y remedier: premierement, par l'amelioration du mode d'acquisition des donnees et des performances du sous-ensemble charge de cette acquisition; deuxiemement, par la recherche de methodes de traitement des donnees propres a reduire les distorsions de l'image et en premier lieu l'astigmatisme du au collimateur. La premiere partie en est devolue a l'etude de la formation de l'image par l'intermediaire de la grille collimatrice, la seconde a l'examen de nombreux systemes utilisables pour l'acquisition des donnees. La derniere partie resume les experiences effectuees et propose un programme de manipulations utiles a l'elaboration d'un prototype d'appareil. (auteur)

  4. Size Effect on Acoustic Emission Characteristics of Coal-Rock Damage Evolution

    OpenAIRE

    Wen, Zhijie; Wang, Xiao; Chen, Lianjun; Lin, Guan; Zhang, Hualei

    2017-01-01

    Coal-gas outburst, rock burst, and other mine dynamic disasters are closely related to the instability and failure of coal-rock. Coal-rock is the assemblies of mineral particles of varying sizes and shapes bonded together by cementing materials. The damage and rupture process of coal-rock is accompanied by acoustic emission (AE), which can be used as an effective means to monitor and predict the instability of coal-rock body. In this manuscript, considering the size effect of coal-rock, the i...

  5. VIRTUAL HERITAGE ARCHIVES: BUILDING A CENTRALIZED AUSTRALIAN ROCK ART ARCHIVE

    Directory of Open Access Journals (Sweden)

    R. A. Haubt

    2013-07-01

    Full Text Available This paper examines use of multi-media in the curation, presentation and promotion of rock art. It discusses the construction of a centralised Australian rock art database and explores new technologies available for looking at rock art. In 2011, Prof. Taçon Chair in Rock Art Research and Director of PERAHU (Place, Evolution and Rock Art Heritage Unit called for a national rock art database raising awareness of the importance of preserving rock art as part of Australia's valuable Indigenous heritage (Taçon, 2011. Australia has over 100,000 rock art sites, important heritage places for Indigenous and non-Indigenous Australians and a testament to over 10,000 years of human activity, including interactions with other peoples and the environment. Many of these sites have not been documented or recorded and are threatened by natural and cultural agents. It is becoming increasingly important to develop conservation models for the protection and preservation of sites. Indigenous cultural heritage is difficult to manage on a local government level due to complex human / time / environment relationships and the importance of intangible cultural heritage (SoE SEWPAC, 2011. Currently no centralised database system exists in Australia to curate, present and promote rock art.

  6. Continuous distillation of oil-bearing rocks

    Energy Technology Data Exchange (ETDEWEB)

    1923-11-14

    A continuous process of distilling petroleum-bearing, asphaltic, or bituminous rocks to free bitumen is characterized by vaporizing hydrocarbons solid, pasty, or liquid from petroleum-containing asphaltic or bituminous rocks to free bitumen without ever reaching the temperatures at which they can produce decomposition, the necessary heat being furnished by combustion of part of the hydrocarbons of the treated rocks. A furnace for carrying out the process of claim 1 is characterized by consisting of a cavity lined inside with reflector, of variable section and with a throat at the upper part for charging the material to be treated and means for blowing the lower part of the furnace with the air necessary for combustion and inert gas for regulating the combustion and removal of the hydrocarbons.

  7. Longwave thermal infrared spectral variability in individual rocks

    Energy Technology Data Exchange (ETDEWEB)

    Balick, Lee K [Los Alamos National Laboratory; Gillespie, Alan [UN. WASHINGTON; French, Andrew [USDA-ARS; Danilina, Iryna [UN. WASHINGTON

    2008-01-01

    A hyperspectral imaging spectrometer measuring in the longwave thermal infrared (7.6-11.6 {micro}m) with a spatial resolution less than 4 mm was used in the field to observe the variability of emissivity spectra within individual rocks. The rocks were obtained commercially, were on the order of 20 cm in size and were selected to have distinct spectral features: they include alabaster (gypsum), soapstone (steatite with talc), obsidian (volcanic glass), norite (plagioclase and orthopyroxene), and 'jasper' (silica with iron oxides). The advantages of using an imaging spectrometer to spectrally characterize these rocks are apparent. Large spectral variations were observed within individual rocks that may be attributed to roughness, surface geometry, and compositional variation. Non-imaging spectrometers would normally miss these variations as would small samples used in laboratory measurements, spatially averaged spectra can miss the optimum spectra for identification materials and spatially localized components of the rock can be obscured.

  8. Crustal contamination versus an enriched mantle source for intracontinental mafic rocks: Insights from early Paleozoic mafic rocks of the South China Block

    Science.gov (United States)

    Xu, Wenjing; Xu, Xisheng; Zeng, Gang

    2017-08-01

    Several recent studies have documented that the silicic rocks (SiO2 > 65 wt.%) comprising Silicic Large Igneous Provinces are derived from partial melting of the crust facilitated by underplating/intraplating of "hidden" large igneous province-scale basaltic magmas. The early Paleozoic intracontinental magmatic rocks in the South China Block (SCB) are dominantly granitoids, which cover a combined area of 22,000 km2. In contrast, exposures of mafic rocks total only 45 km2. These mafic rocks have extremely heterogeneous isotopic signatures that range from depleted to enriched (whole rock initial 87Sr/86Sr = 0.7041-0.7102; εNd(t) = - 8.4 to + 1.8; weighted mean zircon εHf(t) = - 7.4 to + 5.2), show low Ce/Pb and Nb/U ratios (0.59-13.1 and 3.5-20.9, respectively), and variable Th/La ratios (0.11-0.51). The high-MgO mafic rocks (MgO > 10 wt.%) tend to have lower εNd(t) values (- 4) and Sm/Nd ratios (> 0.255). The differences in geochemistry between the high-MgO and low-MgO mafic rocks indicate greater modification of the compositions of high-MgO mafic magmas by crustal material. In addition, generally good negative correlations between εNd(t) and initial 87Sr/86Sr ratios, MgO, and K2O, along with the presence of inherited zircons in some plutons, indicate that the geochemical and isotopic compositions of the mafic rocks reflect significant crustal contamination, rather than an enriched mantle source. The results show that high-MgO mafic rocks with fertile isotopic compositions may be indicative of crustal contamination in addition to an enriched mantle source, and it is more likely that the lithospheric mantle beneath the SCB during the early Paleozoic was moderately depleted than enriched by ancient subduction processes.

  9. Dynamic stability and failure modes of slopes in discontinuous rock mass

    International Nuclear Information System (INIS)

    Shimizu, Yasuhiro; Aydan, O.; Ichikawa, Yasuaki; Kawamoto, Toshikazu.

    1988-01-01

    The stability of rock slopes during earthquakes are of great concern in rock engineering works such as highway, dam, and nuclear power station constructions. As rock mass in nature is usually discontinuous, the stability of rock slopes will be geverned by the spatial distribution of discontinuities in relation with the geometry of slope and their mechanical properties rather than the rock element. The authors have carried out some model tests on discontinuous rock slopes using three different model tests techniques in order to investigate the dynamic behaviour and failure modes of the slopes in discontinuous rock mass. This paper describes the findings and observations made on model rock slopes with various discontinuity patterns and slope geometry. In addition some stability criterions are developed and the calculated results are compared with those of experiments. (author)

  10. Size Effect on Acoustic Emission Characteristics of Coal-Rock Damage Evolution

    Directory of Open Access Journals (Sweden)

    Zhijie Wen

    2017-01-01

    Full Text Available Coal-gas outburst, rock burst, and other mine dynamic disasters are closely related to the instability and failure of coal-rock. Coal-rock is the assemblies of mineral particles of varying sizes and shapes bonded together by cementing materials. The damage and rupture process of coal-rock is accompanied by acoustic emission (AE, which can be used as an effective means to monitor and predict the instability of coal-rock body. In this manuscript, considering the size effect of coal-rock, the influence of different height to diameter ratio on the acoustic emission characteristics of coal-rock damage evolution was discussed by microparticle flow PFC2D software platform. The results show that coal-rock size influences the uniaxial compressive strength, peak strain, and elastic modulus of itself; the size effect has little effect on the acoustic emission law of coal-rock damage and the effects of the size of coal-rock samples on acoustic emission characteristics are mainly reflected in three aspects: the triggering time of acoustic emission, the strain range of strong acoustic emission, and the intensity of acoustic emission; the damage evolution of coal-rock specimen can be divided into 4 stages: initial damage, stable development, accelerated development, and damage.

  11. The December 2008 Crammont rock avalanche, Mont Blanc massif area, Italy

    Directory of Open Access Journals (Sweden)

    P. Deline

    2011-12-01

    Full Text Available We describe a 0.5 Mm3 rock avalanche that occurred in 2008 in the western Alps and discuss possible roles of controlling factors in the context of current climate change. The source is located between 2410 m and 2653 m a.s.l. on Mont Crammont and is controlled by a densely fractured rock structure. The main part of the collapsed rock mass deposited at the foot of the rock wall. A smaller part travelled much farther, reaching horizontal and vertical travel distances of 3050 m and 1560 m, respectively. The mobility of the rock mass was enhanced by channelization and snow. The rock-avalanche volume was calculated by comparison of pre- and post-event DTMs, and geomechanical characterization of the detachment zone was extracted from LiDAR point cloud processing. Back analysis of the rock-avalanche runout suggests a two stage event.

    There was no previous rock avalanche activity from the Mont Crammont ridge during the Holocene. The 2008 rock avalanche may have resulted from permafrost degradation in the steep rock wall, as suggested by seepage water in the scar after the collapse in spite of negative air temperatures, and modelling of rock temperatures that indicate warm permafrost (T > −2 °C.

  12. Drill-back studies examine fractured, heated rock

    International Nuclear Information System (INIS)

    Wollenberg, H.A.; Flexser, S.; Myer, L.R.

    1990-01-01

    To investigate the effects of heating on the mineralogical, geochemical, and mechanical properties of rock by high-level radioactive waste, cores are being examined from holes penetrating locations where electric heaters simulated the presence of a waste canister, and from holes penetration natural hydrothermal systems. Results to date indicate the localized mobility and deposition of uranium in an open fracture in heated granitic rock, the mobility of U in a breccia zone in an active hydrothermal system in tuff, and the presence of U in relatively high concentration in fracture-lining material in tuff. Mechanical -- property studies indicate that differences in compressional- and shear-wave parameters between heated and less heated rock can be attributed to differences in the density of microcracks. Emphasis has shifted from initial studies of granitic rock at Stripa, Sweden to current investigations of welded tuff at the Nevada Test Site. 7 refs., 8 figs

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

    Science.gov (United States)

    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.

  14. Anisotropy effect on strengths of metamorphic rocks

    Directory of Open Access Journals (Sweden)

    Ahmet Özbek

    2018-02-01

    Full Text Available This paper aims to study the effect of anisotropy on strengths of several metamorphic rocks of southern (Çine submassif of Menderes metamorphic massif in southwest Turkey. Four different metamorphic rocks including foliated phyllite, schist, gneiss and marble (calcschist were selected and examined. Discontinuity surveys were made along lines for each rock and evaluated with DIPS program. L-type Schmidt hammer was applied in the directions parallel and perpendicular to foliation during the field study. Several hand samples and rock blocks were collected during the field study for measurements of dry and saturated densities, dry and saturated unit weights and porosity, and for petrographic analysis and strength determination in laboratory. L- and N-type Schmidt hammers were applied in the directions perpendicular (anisotropy angle of 0° and parallel (anisotropy angle of 90° to the foliation on selected blocks of phyllite, schist, gneiss and marble (calcschist. The phyllite and schist have higher porosity and lower density values than the other rocks. However, coarse crystalline gneiss and marble (calcschist have higher rebound values and strengths, and they are classified as strong–very strong rocks. Generally, the rebound values in the direction perpendicular to the foliation are slightly higher than that in the direction parallel to foliation. Rebound values of N-type Schmidt hammer are higher than the L-type values except for phyllite. Sometimes, the rebound values of laboratory and field applications gave different results. This may result from variable local conditions such as minerals differentiation, discontinuities, water content, weathering degree and thickness of foliated structure.

  15. Theoretical study of rock mass investigation efficiency

    International Nuclear Information System (INIS)

    Holmen, Johan G.; Outters, Nils

    2002-05-01

    The study concerns a mathematical modelling of a fractured rock mass and its investigations by use of theoretical boreholes and rock surfaces, with the purpose of analysing the efficiency (precision) of such investigations and determine the amount of investigations necessary to obtain reliable estimations of the structural-geological parameters of the studied rock mass. The study is not about estimating suitable sample sizes to be used in site investigations.The purpose of the study is to analyse the amount of information necessary for deriving estimates of the geological parameters studied, within defined confidence intervals and confidence level In other words, how the confidence in models of the rock mass (considering a selected number of parameters) will change with amount of information collected form boreholes and surfaces. The study is limited to a selected number of geometrical structural-geological parameters: Fracture orientation: mean direction and dispersion (Fisher Kappa and SRI). Different measures of fracture density (P10, P21 and P32). Fracture trace-length and strike distributions as seen on horizontal windows. A numerical Discrete Fracture Network (DFN) was used for representation of a fractured rock mass. The DFN-model was primarily based on the properties of an actual fracture network investigated at the Aespoe Hard Rock Laboratory. The rock mass studied (DFN-model) contained three different fracture sets with different orientations and fracture densities. The rock unit studied was statistically homogeneous. The study includes a limited sensitivity analysis of the properties of the DFN-model. The study is a theoretical and computer-based comparison between samples of fracture properties of a theoretical rock unit and the known true properties of the same unit. The samples are derived from numerically generated boreholes and surfaces that intersect the DFN-network. Two different boreholes are analysed; a vertical borehole and a borehole that is

  16. Rock melting technology and geothermal drilling

    Science.gov (United States)

    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.

  17. Thermo-hydro-mechanical behavior of fractured rock mass

    International Nuclear Information System (INIS)

    Coste, F.

    1997-12-01

    The purpose of this research is to model Thermo-Hydro-Mechanical behavior of fractured rock mass regarding a nuclear waste re-depository. For this, a methodology of modeling was proposed and was applied to a real underground site (EDF site at Nouvelle Romanche). This methodology consists, in a first step, to determine hydraulic and mechanical REV. Beyond the greatest of these REV, development of a finite element code allows to model all the fractures in an explicit manner. The homogenized mechanical properties are determined in drained and undrained boundary conditions by simulating triaxial tests that represent rock mass subject to loading. These simulations allow to study the evolution of hydraulic and mechanical properties as a function of stress state. Drained and undrained boundary conditions enable to discuss the validity of assimilation of a fractured rock mass to a porous medium. The simulations lead to a better understanding of the behavior of the fractured rock masses and allow to show the dominant role of the shear behavior of the fractures on the hydraulic and mechanical homogenized properties. From a thermal point of view, as long as conduction is dominant, thermal properties of the rock mass are almost the same as those the intact rock. (author)

  18. Geochemical investigation of petroleum source rocks by using Rock- Eval data in the Agha-Jari oilfield

    Directory of Open Access Journals (Sweden)

    Behzad khani

    2015-01-01

    Full Text Available In this study, 40 drilling cutting of the Pabdeh, Gurpi, kazhdumi and Gadvan Formations from the Agha-Jari Oilfield were analyzed by using Rock-Eval pyrolysis. In order to recognizing sedimentary environmental conditions of studied Formations, they are divided to 4 zones which A (Kazhdumi Formation#187 and C (Kazhdumi Formation#140 zones show reduction conditions by presence of sea organic materials and B (Gadvan Formation #140 and D(Gadvan Formation#187 zones show oxidation conditions by presence of continental organic materials to basin. Based on the Rock-Eval pyrolysis data, the Pabeh, Gurpi, Kazhdumi and Gadvan Formations have variable hydrocarbon generative potential. HI vs. OI plot revealed that the kerogen type in this Formations is a mixed of types II & III. The intensity of matrix effect in the Pabdeh, Gurpi, Kazhdumi and Gadvan Formations was compared by using S2 vs. TOC plot and calculating its regression equation. The results show that the significant amount of S2 adsorption by matrix was happened in the Pabdeh (4.98-6.96 mg HC/gr rock in wells 113 and 121 and Gurpi Formations ‌(4.33 mg HC/gr rock in well 113 which is due to their low thermal maturity‌(Tmax

  19. Multiaxial loading of large-diameter, thin-walled tube rock specimens

    International Nuclear Information System (INIS)

    Hecker, S.S.; Petrovic, J.J.

    1981-01-01

    A large-scale mechanical testing facility permits previously impossible thin-walled tube multiaxial loading experiments on rock materials. Constraints are removed regarding tube wall thickness in relation to rock microstructural features and tube diameter as well as test machine load capacity. Thin-walled tube studies clarify the influence of intermediate principal stress sigma 2 on rock fracture and help define a realistic rock fracture criterion for all multiaxial stressing situations. By comparing results of thin-walled and thick-walled tube fracture investigations, effects of stress gradients can be established. Finally, influence of stress path on rock fracture, an area largely ignored in current rock failure criteria, can be examined in detail using controlled loading changes as well as specimen prestrains

  20. Rock mechanics stability at Olkiluoto, Haestholmen, Kivetty and Romuvaara

    International Nuclear Information System (INIS)

    Johansson, E.; Rautakorpi, J.

    2000-02-01

    Posiva Oy is studying the suitability of the Finnish bedrock for the geological disposal of spent nuclear fuel at four sites, Olkiluoto in Eurajoki, Haestholmen in Loviisa, Kivetty in Aeaenekoski and Romuvaara in Kuhmo. To enable the rock properties to be specified in great detail, the site-selection research programme has included rock mechanics investigations such as the measurement of in-situ rock stress and laboratory tests on rock samples. This report presents the results of the rock mechanics analyses performed on the main rock types at the Olkiluoto, Romuvaara, Kivetty and Haestholmen sites. The objective of this study was to assess the near-field stability of the final disposal tunnels and deposition holes at each of the investigation sites. Two empirical methods and a numerical method based on three-dimensional element code (3DEC) were used the analysis tools. A statistical approach was used to select the necessary input data and to specify the cases being analysed. The stability of the KBS-3 and MLH (Medium Long Hole) repository concepts during the pre-closure and post-closure phases was analysed. The repository depths investigated lay between 300 m and 700 m. The empirical methods are based on the study of the ratios between rock strength and the in-situ stress which could result in possible fracturing of the rock mass. Interpretation of the numerical analyses is based on the assumption of an elastic distribution of stress around the disposal tunnel and the deposition hole and the brittle rock strength criterion. The results obtained in this study indicate that in general, the rock mechanics conditions during the pre-closure and post-closure phases at each of the investigated sites remain good and stable between the studied depth levels, especially when the deposition rooms are oriented in a direction parallel to the major in-situ stress. If the disposal tunnels are orientated in a direction perpendicular to the major in-situ stress, the resultant

  1. Survey on the characteristics of rock under low and high temperature

    International Nuclear Information System (INIS)

    Shin, Koich; Kitano, Koichi

    1987-01-01

    Rock caverns for Superconducting Magnetic Energy Storage (SMES), Radioactive Waste Disposal, or Liquified Natural Gas Storage will suffer extraordinary temperature. Therefore, authors have researched the rock characteristics under the low temperature conditions and the rock mass behavior when it is heated, by papers so far reported. As a result, rock characteristics such as strength, linear expansion coefficient, thermal conductivity etc. are found to be ready to change with temperature condition and the kind of rocks. Even an anisotropy of some kind appears under some conditions. So, when sitting those facilities before mentioned, rock characteristics under each temperature condition must be enough clarified for the purpose of the evaluation of rock cavern stability and especially, rock behavior when it is loaded dynamically under low temperature must be cleared from now on, for such studies have been few. (author)

  2. Rock mechanics activities at the Waste Isolation Pilot Plant

    International Nuclear Information System (INIS)

    Francke, C.; Saeb, S.

    1996-01-01

    The application of rock mechanics at nuclear waste repositories is a true multidisciplinary effort. A description and historical summary of the Waste Isolation Pilot Plant (WIPP) is presented. Rock mechanics programs at the WIPP are outlined, and the current rock mechanics modeling philosophy of the Westinghouse Waste Isolation Division is discussed

  3. An Overview of the Soutpansberg Sedimentary and Volcanic Rocks

    Directory of Open Access Journals (Sweden)

    J.W. Bristow

    1986-11-01

    Full Text Available Volcanic and sedimentary rocks occupy a faulted graben within the previously uplifted and eroded high-grade gneiss terrain of the Limpopo Mobile Belt. The rocks comprise the Soutpansberg Group and represent an important sequence of Proterozoic rocks. Their general geology and volcanology is summarised in this paper.

  4. Rock glaciers in the Suntar‑Khayata Range

    Directory of Open Access Journals (Sweden)

    V. M. Lytkin

    2016-01-01

    Full Text Available The remote map‑making technique and results of field investigations made possible for the first time to reveal a great number of rock glaciers within the area of the Suntar‑Khayata Range (North‑East Asia. A total of 540 formations were identified. Among them, 47 rock glaciers were classified as corrie (cirque tongue‑shaped formations and 493 ones – as niche lobe‑shaped (single‑ and multi‑lobe rock glaciers. Occurrence of such formations is 8.4/100 km2, that is the largest in the North‑East Asia. The rock glaciers in this region are found within a range of true altitudes from 1297 up to 2402 m asl. The majority of active features, however, are confined to the interval between 1500 and 1900 m asl. Rock glaciers occur in the altitudinal range of 1297 to 2402 m asl. The majority of active features, however, are confined to the interval between 1500 and 1900 m asl, and the main part of active formations is located within the range of 1500‑2500 m. The frequency analysis of true altitudes of the rock‑glacier occurrence indicates that their formation can be caused by the hypsometry of the region relation to morphoclimatic zonality.

  5. Transient evoked otoacoustic emissions in rock musicians.

    Science.gov (United States)

    Høydal, Erik Harry; Lein Størmer, Carl Christian; Laukli, Einar; Stenklev, Niels Christian

    2017-09-01

    Our focus in this study was the assessment of transient evoked otoacoustic emissions (TEOAEs) in a large group of rock musicians. A further objective was to analyse tinnitus among rock musicians as related to TEOAEs. The study was a cross-sectional survey of rock musicians selected at random. A control group was included at random for comparison. We recruited 111 musicians and a control group of 40 non-musicians. Testing was conducted by using clinical examination, pure tone audiometry, TEOAEs and a questionnaire. TEOAE SNR in the half-octave frequency band centred on 4 kHz was significantly lower bilaterally in musicians than controls. This effect was strongly predicted by age and pure-tone hearing threshold levels in the 3-6 kHz range. Bilateral hearing thresholds were significantly higher at 6 kHz in musicians. Twenty percent of the musicians had permanent tinnitus. There was no association between the TEOAE parameters and permanent tinnitus. Our results suggest an incipient hearing loss at 6 kHz in rock musicians. Loss of TEOAE SNR in the 4 kHz half-octave frequency band was observed, but it was related to higher mean 3-6 kHz hearing thresholds and age. A large proportion of rock musicians have permanent tinnitus.

  6. Inelastic deformations of fault and shear zones in granitic rock

    International Nuclear Information System (INIS)

    Wilder, D.G.

    1986-02-01

    Deformations during heating and cooling of three drifts in granitic rock were influenced by the presence of faults and shear zones. Thermal deformations were significantly larger in sheared and faulted zones than where the rock was jointed, but neither sheared nor faulted. Furthermore, thermal deformations in faulted or sheared rock were not significantly recovered during subsequent cooling, thus a permanent deformation remained. This inelastic response is in contrast with elastic behavior identified in unfaulted and unsheared rock segments. A companion paper indicates that deformations in unsheared or unfaulted rock were effectively modeled as an elastic response. We conclude that permanent deformations occurred in fractures with crushed minerals and fracture filling or gouge materials. Potential mechanisms for this permanent deformation are asperity readjustments during thermal deformations, micro-shearing, asperity crushing and crushing of the secondary fracture filling minerals. Additionally, modulus differences in sheared or faulted rock as compared to more intact rock would result in greater deformations in response to the same thermal loads

  7. Rock excavation by pulsed electron beams

    International Nuclear Information System (INIS)

    Avery, R.T.; Keefe, D.; Brekke, T.L.; Finnie, I.

    1976-03-01

    If an intense short pulse of megavolt electrons is deposited in a brittle solid, dynamic spalling can be made to occur with removal of material. Experiments were made on several types of hard rock; results are reproducible and well-described theoretically. An accelerator with a rapidly-pulsed scanning electron beam was designed that could tunnel in hard rock about ten times faster than conventional drill/blast methods

  8. Study of copper fluorination; Contribution a l'etude de la fluoruration du cuivre

    Energy Technology Data Exchange (ETDEWEB)

    Gillardeau, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1967-02-01

    This report deals with the action of fluorine on copper. Comprehensive descriptions are given of the particular technological methods and of the preparation of the reactants. This fluorination reaction has been studied at medium and low fluorine pressures. A nucleation and growth phenomenon is described. The influence of a pollution of the gas phase on the fluorination process is described. The solid-state reaction between cupric fluoride and cooper has also been studied. A special study has been made of the growth of copper deposits by thermal decomposition of gaseous fluorides. (author) [French] Ce rapport traite de la reaction du fluor sur le cuivre. Les methodes technologiques particulieres ainsi que les preparations des reactifs sont largement developpees. Cette reaction de fluoruration est etudiee sous pressions moyennes et sous basses pressions de fluor. Un phenomene de germination et croissance est decrit. L'influence de la pollution de la phase gazeuse sur le processus de fluoruration est rapportee. La reaction a l'etat solide du fluorure cuivrique sur le cuivre a egalement ete etudiee. La croissance de depots de cuivre par decomposition thermique des fluorures de cuivre gazeux fait l'objet d'une etude speciale. (auteur)

  9. Mineralogical and geochemical investigation of the Oligocene sedimentary series of Saint-Agoulin; Etude mineralogique et geochimique de la serie sedimentaire oligocene de Saint-Agoulin

    Energy Technology Data Exchange (ETDEWEB)

    Mohadjer, K [Commissariat a l' Energie Atomique, 92 - Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires, direction des productions; Faculte des Sciences de l' Universite de Paris, 75 (France)

    1967-07-05

    The mineralogical investigation is based on determination of the amounts of quartz, clays, feldspars and on grain size analysis. A distinction was established between two lithological groups: the lower group with dominant silica the upper with dominant carbonates. Clays of the two groups are comparable with dominant illite, and accessory kaolinite and montmorillonite. The amounts of the elements Si, Al, Fe, Ca, Mg, Na, K, Ti, Mn, P, Ba, Sr, Rb, Pb, Cu, Ni, Co, V, Be, B, Zr, U, were determined by several analytical methods: chemistry, X ray fluorescence, spectrography and fluorimetry. Correlations between the chemical elements and the mineralogical components were computed and plotted. Lastly the conditions of filling up of the basin are defined, taking into account the Oligocene climatic conditions. (author) [French] L'etude mineralogique est basee sur les dosages du quartz, de la calcite, des argiles, des feldspaths et sur les granulometries. On a distingue 2 familles lithologiques: l'une riche en quartz dans la partie inferieure, l'autre riche en carbonate dans la partie superieure. Les argiles des 2 familles sont comparables: illite predominante, kaolinite et montmorillonite accessoires. Les elements: Si, Al, Fe, Ca, Mg, Na, K, Ti, Mn, P, Ba, Sr, Rb, Pb, Cu, Ni, Co, V, Be, B, Zr, U, ont ete doses par differentes methodes d'analyse: analyse chimique, fluorescence X, spectrographie et fluorimetrie. Une etude de correlation entre les elements chimiques et les constituants mineralogiques a ete realisee. Enfin, les conditions de remplissage du Bassin sont definies, en tenant compte du contexte climatique oligocene. (auteur)

  10. Rock mass mechanical property estimations for the Yucca Mountain Site Characterization Project

    International Nuclear Information System (INIS)

    Lin, M.; Hardy, M.P.; Bauer, S.J.

    1993-06-01

    Rock mass mechanical properties are important in the design of drifts and ramps. These properties are used in evaluations of the impacts of thermomechanical loading of potential host rock within the Yucca Mountain Site Characterization Project. Representative intact rock and joint mechanical properties were selected for welded and nonwelded tuffs from the currently available data sources. Rock mass qualities were then estimated using both the Norwegian Geotechnical Institute (Q) and Geomechanics Rating (RMR) systems. Rock mass mechanical properties were developed based on estimates of rock mass quality, the current knowledge of intact properties, and fracture/joint characteristics. Empirical relationships developed to correlate the rock mass quality indices and the rock mass mechanical properties were then used to estimate the range of rock mass mechanical properties

  11. Conducting Rock Mass Rating for tunnel construction on Mars

    Science.gov (United States)

    Beemer, Heidi D.; Worrells, D. Scott

    2017-10-01

    Mars analogue missions provide researchers, scientists, and engineers the opportunity to establish protocols prior to sending human explorers to another planet. This paper investigated the complexity of a team of simulation astronauts conducting a Rock Mass Rating task during Analogue Mars missions. This study was conducted at the Mars Desert Research Station in Hanksville, UT, during field season 2015/2016 and with crews 167,168, and 169. During the experiment, three-person teams completed a Rock Mass Rating task during a three hour Extra Vehicular Activity on day six of their two-week simulation mission. This geological test is used during design and construction of excavations in rock on Earth. On Mars, this test could be conducted by astronauts to determine suitable rock layers for tunnel construction which would provide explorers a permanent habitat and radiation shielding while living for long periods of time on the surface. The Rock Mass Rating system derives quantitative data for engineering designs that can easily be communicated between engineers and geologists. Conclusions from this research demonstrated that it is feasible for astronauts to conduct the Rock Mass Rating task in a Mars simulated environment. However, it was also concluded that Rock Mass Rating task orientation and training will be required to ensure that accurate results are obtained.

  12. The Rock Characterization Facility

    International Nuclear Information System (INIS)

    Holmes, J.

    1994-01-01

    In 1989, UK Nirex began a programme of surface-based characterization of the geology and hydrogeology of a site at Sellafield to evaluate its suitability to host a deep repository for radioactive waste. The next major stage in site characterization will be the construction and operation of a Rock Characterization Facility (RCF). It will be designed to provide rock characterization information and scope for model validation to permit firmer assessment of long-term safety. It will also provide information needed to decide the detailed location, design and orientation of a repository and to inform repository construction methods. A three-phase programme is planned for the RCF. During each phase, testwork will steadily improve our geological, hydrogeological and geotechnical understanding of the site. The first phase will involve sinking two shafts. That will be preceded by the establishment of a network of monitoring boreholes to ensure that the impact of shaft sinking can be measured. This will provide valuable data for model validation. In phase two, initial galleries will be excavated, probably at a depth of 650 m below Ordnance datum, which will host a comprehensive suite of experiments. These galleries will be extended in phase three to permit access to most of the rock volume that would host the repository. (Author)

  13. Development of an analogue multiplexed regulation for periodic 1. order delayed processes; Etude et realisation d'une regulation analogique multiplexee pour processus aperiodiques du 1. ordre avec retard pur

    Energy Technology Data Exchange (ETDEWEB)

    Amblard, J.C. [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1967-07-15

    The present note deals with the study regulations of the sampled type, for 1. order process with simple delay. In order to obtain a good stability in such regulations, together with acceptable performances, it is interesting to use polynomial type correctors acting directly on the sampled error signals. The active elements of these correctors can be shared by all the channels to be controlled. Furthermore, the determination of the correction parameters results from an optimal study of the system. In the second part is described the construction of a multiplexed regulation for diffusion ovens. (author) [French] La presente note concerne l'etude des regulations de type echantillonne, pour processus du 1. ordre avec retard pur. Pour obtenir une bonne stabilite de telles regulations, ainsi que des performances correcte il est interessant d'utiliser des correcteurs de type polynomial, agissant directement sur les signaux d'erreur echantillonnes. Les elements actifs de ces correcteurs peuvent etre pris communs a toutes les voies a controler. D'autre part, la determination des parametres de correction decoula d'une etude optimale du systeme. Dans une seconde partie on decrit la realisation d'une regulation multiplexee de fours a diffusion. (auteur)

  14. Constitutive relationships for elastic deformation of clay rock: Data Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Liu, H.H.; Rutqvist, J.; Birkholzer, J.T.

    2011-04-15

    Geological repositories have been considered a feasible option worldwide for storing high-level nuclear waste. Clay rock is one of the rock types under consideration for such purposes, because of its favorable features to prevent radionuclide transport from the repository. Coupled hydromechanical processes have an important impact on the performance of a clay repository, and establishing constitutive relationships for modeling such processes are essential. In this study, we propose several constitutive relationships for elastic deformation in indurated clay rocks based on three recently developed concepts. First, when applying Hooke's law in clay rocks, true strain (rock volume change divided by the current rock volume), rather than engineering strain (rock volume change divided by unstressed rock volume), should be used, except when the degree of deformation is very small. In the latter case, the two strains will be practically identical. Second, because of its inherent heterogeneity, clay rock can be divided into two parts, a hard part and a soft part, with the hard part subject to a relatively small degree of deformation compared with the soft part. Third, for swelling rock like clay, effective stress needs to be generalized to include an additional term resulting from the swelling process. To evaluate our theoretical development, we analyze uniaxial test data for core samples of Opalinus clay and laboratory measurements of single fractures within macro-cracked Callovo-Oxfordian argillite samples subject to both confinement and water reduced swelling. The results from this evaluation indicate that our constitutive relationships can adequately represent the data and explain the related observations.

  15. Constitutive relationships for elastic deformation of clay rock: Data Analysis

    International Nuclear Information System (INIS)

    Liu, H.H.; Rutqvist, J.; Birkholzer, J.T.

    2011-01-01

    Geological repositories have been considered a feasible option worldwide for storing high-level nuclear waste. Clay rock is one of the rock types under consideration for such purposes, because of its favorable features to prevent radionuclide transport from the repository. Coupled hydromechanical processes have an important impact on the performance of a clay repository, and establishing constitutive relationships for modeling such processes are essential. In this study, we propose several constitutive relationships for elastic deformation in indurated clay rocks based on three recently developed concepts. First, when applying Hooke's law in clay rocks, true strain (rock volume change divided by the current rock volume), rather than engineering strain (rock volume change divided by unstressed rock volume), should be used, except when the degree of deformation is very small. In the latter case, the two strains will be practically identical. Second, because of its inherent heterogeneity, clay rock can be divided into two parts, a hard part and a soft part, with the hard part subject to a relatively small degree of deformation compared with the soft part. Third, for swelling rock like clay, effective stress needs to be generalized to include an additional term resulting from the swelling process. To evaluate our theoretical development, we analyze uniaxial test data for core samples of Opalinus clay and laboratory measurements of single fractures within macro-cracked Callovo-Oxfordian argillite samples subject to both confinement and water reduced swelling. The results from this evaluation indicate that our constitutive relationships can adequately represent the data and explain the related observations.

  16. Mechanical weathering and rock erosion by climate-dependent subcritical cracking

    Science.gov (United States)

    Eppes, Martha-Cary; Keanini, Russell

    2017-06-01

    This work constructs a fracture mechanics framework for conceptualizing mechanical rock breakdown and consequent regolith production and erosion on the surface of Earth and other terrestrial bodies. Here our analysis of fracture mechanics literature explicitly establishes for the first time that all mechanical weathering in most rock types likely progresses by climate-dependent subcritical cracking under virtually all Earth surface and near-surface environmental conditions. We substantiate and quantify this finding through development of physically based subcritical cracking and rock erosion models founded in well-vetted fracture mechanics and mechanical weathering, theory, and observation. The models show that subcritical cracking can culminate in significant rock fracture and erosion under commonly experienced environmental stress magnitudes that are significantly lower than rock critical strength. Our calculations also indicate that climate strongly influences subcritical cracking—and thus rock weathering rates—irrespective of the source of the stress (e.g., freezing, thermal cycling, and unloading). The climate dependence of subcritical cracking rates is due to the chemophysical processes acting to break bonds at crack tips experiencing these low stresses. We find that for any stress or combination of stresses lower than a rock's critical strength, linear increases in humidity lead to exponential acceleration of subcritical cracking and associated rock erosion. Our modeling also shows that these rates are sensitive to numerous other environment, rock, and mineral properties that are currently not well characterized. We propose that confining pressure from overlying soil or rock may serve to suppress subcritical cracking in near-surface environments. These results are applicable to all weathering processes.

  17. Scale dependence of rock friction at high work rate.

    Science.gov (United States)

    Yamashita, Futoshi; Fukuyama, Eiichi; Mizoguchi, Kazuo; Takizawa, Shigeru; Xu, Shiqing; Kawakata, Hironori

    2015-12-10

    Determination of the frictional properties of rocks is crucial for an understanding of earthquake mechanics, because most earthquakes are caused by frictional sliding along faults. Prior studies using rotary shear apparatus revealed a marked decrease in frictional strength, which can cause a large stress drop and strong shaking, with increasing slip rate and increasing work rate. (The mechanical work rate per unit area equals the product of the shear stress and the slip rate.) However, those important findings were obtained in experiments using rock specimens with dimensions of only several centimetres, which are much smaller than the dimensions of a natural fault (of the order of 1,000 metres). Here we use a large-scale biaxial friction apparatus with metre-sized rock specimens to investigate scale-dependent rock friction. The experiments show that rock friction in metre-sized rock specimens starts to decrease at a work rate that is one order of magnitude smaller than that in centimetre-sized rock specimens. Mechanical, visual and material observations suggest that slip-evolved stress heterogeneity on the fault accounts for the difference. On the basis of these observations, we propose that stress-concentrated areas exist in which frictional slip produces more wear materials (gouge) than in areas outside, resulting in further stress concentrations at these areas. Shear stress on the fault is primarily sustained by stress-concentrated areas that undergo a high work rate, so those areas should weaken rapidly and cause the macroscopic frictional strength to decrease abruptly. To verify this idea, we conducted numerical simulations assuming that local friction follows the frictional properties observed on centimetre-sized rock specimens. The simulations reproduced the macroscopic frictional properties observed on the metre-sized rock specimens. Given that localized stress concentrations commonly occur naturally, our results suggest that a natural fault may lose its

  18. Rock stress investigations

    International Nuclear Information System (INIS)

    Pahl, A.; Heusermann, St.; Braeuer, V.; Gloeggler, W.

    1989-04-01

    On the research project 'Rock Stress Mesurements' the BGR has developed and tested several methods for use in boreholes at a depth of 200 m. Indirect stress measurements using overcoring methods with BGR-probes and CSIR-triaxial cells as well as direct stress measurements using the hydraulic-fracturing method were made. To determine in-situ rock deformation behavior borehole deformation tests, using a BGR-dilatometer, were performed. Two types of the BGR-probe were applied: a four-component-probe to determine horizontal stresses and a five-component-probe to determine a quasi three-dimensional stress field. The first time a computer for data processing was installed in the borehole together with the BGR-probe. Laboratory tests on low cylinders were made to study the stress-deformation behavior. To validate and to interprete the measurement results some test methods were modelled using the finite-element method. The dilatometer-tests yielded high values of Young's modulus, whereas laboratory tests showed lower values with a distinct deformation anisotropy. Stress measurements with the BGR-probe yielded horizontal stresses being higher than the theoretical overburden pressure. These results are comparable to the results of the hydraulic fracturing tests, whereas stresses obtained with CSIR-triaxial cells are lower. The detailed geological mapping of the borehole indicated relationships between stress and geology. With regard to borehole depth different zones of rock structure joint frequency, joint orientation, and orientation of microfissures as well as stress magnitude, stress direction, and degree of deformation anisotropy could be distinguished. (author) 4 tabs., 76 figs., 31 refs

  19. Fluid-Evaporation Records Preserved in Meridiani Rocks

    Science.gov (United States)

    Rao, M. N.; Nyquist, Laurence E.; Sutton, S. R.

    2009-01-01

    We have shown earlier that the high SO3/Cl ratios found in secondary mineral assemblages in shergottite GRIM glasses (Gas-Rich Impact-Melt) likely resulted from interactions of regolith materials with sulfate-rich (and Cl-poor) solutions. The low SO3/Cl ratios determined in secondary salts in nakhalite fracture-fillings presumably formed by rock interactions with chloride-rich (and SO4-poor) solutions near Mars surface. The SO3 and Cl abundances determined by APXS in abraded rocks (RAT) from Endurance, Fram and Eagle craters indicate that these salt assemblages likely formed by evaporative concentration of brine fluids at Meridiani. The SO3/Cl ratios in the abraded rocks are examined here, instead of their absolute abundances, because the abundance ratios might provide better guide-lines for tracking the evolution of evaporating fluids at Meridiani. The SO3/Cl ratios in these samples, in turn, might provide clues for the mobile element ratios of the altering fluids that infiltrated into the Meridiani rocks.

  20. Classification and Distribution of Mars Pathfinder Rocks Using Quantitative Morphologic Indices

    Science.gov (United States)

    Yingst, R. A.; Biederman, K. L.; Monhead, A. M.; Haldemann, A. F. C.; Kowalczyk, M. R.

    2004-01-01

    The Mars Pathfinder (MPF) landing site was predicted to contain a broad sampling of rock types varying in mineralogical, physical, mechanical and geochemical characteristics. Although rocks have been divided into several spectral categories based on Imager for Mars Pathfinder visible/near-infrared spectra, it has not been fully determined which of these stem from intrinsic mineralogical differences between rocks or rock surfaces, and which result from factors such as physical or chemical weathering. This has made isolation of unique mineralogy's difficult. Efforts in isolating and classifying spectral units among MPF rocks and soils have met with varying degrees of success, and the current understanding is such that many factors influencing spectral signatures cannot be quantified to a sufficient level so they may be removed. The result is that fundamental questions regarding information needed to reveal the present and past interactions between the rocks and rock surfaces and the Martian environment remain unanswered. But it is possible to approach the issue of identifying distinct rock and rock surface types from a different angle.