A paleointensity technique for multidomain igneous rocks

NASA Astrophysics Data System (ADS)

Wang, Huapei; Kent, Dennis V.

2013-10-01

We developed a paleointensity technique to account for concave-up Arai diagrams due to multidomain (MD) contributions to determine unbiased paleointensities for 24 trial samples from site GA-X in Pleistocene lavas from Floreana Island, Galapagos Archipelago. The main magnetization carrier is fine-grained low-titanium magnetite of variable grain size. We used a comprehensive back-zero-forth (BZF) heating technique by adding an additional zero-field heating between the Thellier two opposite in-field heating steps in order to estimate paleointensities in various standard protocols and provide internal self-consistency checks. After the first BZF experiment, we gave each sample a total thermal remanent magnetization (tTRM) by cooling from the Curie point in the presence of a low (15 µT) laboratory-applied field. Then we repeated the BZF protocol, with the laboratory-applied tTRM as a synthetic natural remanent magnetization (NRM), using the same laboratory-applied field and temperature steps to obtain the synthetic Arai signatures, which should only represent the domain-state dependent properties of the samples. We corrected the original Arai diagrams from the first BZF experiment by using the Arai signatures from the repeated BZF experiment, which neutralizes the typical MD concave-up effect. Eleven samples meet the Arai diagram post-selection criteria and provide qualified paleointensity estimates with a mean value for site GA-X of 4.23 ± 1.29 µT, consistent with an excursional geomagnetic field direction reported for this site.

28. Graffiti in north cells: '20 years old 4315 CD ...

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

28. Graffiti in north cells: '20 years old 4315 C-D Mamoru Yoshimoto 5/24/45 180 days Kumamoto'; '18 ' ' years old 1406-A Haruo Yokoi 6/17/45 270 days Nagoya'; '31 ' ' years old 5604-B Masaki Nishii 5/24/45 180 days Kumamoto'; '19 ' ' years old 1806-B Masaharu Yoshida 5/24/45 180 days Hiroshima'; 135mm lens with electronic flash illumination. - Tule Lake Project Jail, Post Mile 44.85, State Route 139, Newell, Modoc County, CA

JPRS Report, Science & Technology, Japan

DTIC Science & Technology

1988-05-06

Sought ( Nobuaki Teraoka; PUROMETEUSU, Nov 87) 62 IPCR Molecular Laser Uranium Enrichment Method Discussed (GENSHIRYOKU IINKAI GEPPO, Nov 87... Kobayashi ) Investigation of Tokyo University character of winter (Professor Tatsuo thunder on Japan Kawamura, Sea side by new Assistant...PUROMETEUSU in Japanese Nov 87 pp 78-81 [Article by Nobuaki Teraoka, Technology Development Division, Atomic Energy Bureau, Science and Technology Agency

Joint Services Electronics Program.

DTIC Science & Technology

1987-12-31

and annealing, using deep level transient spectroscopy (DLTS), and the effects of co-implantation on 4l the activation of amphoteric dopants and...theriithe study of optical quantum effects with emphasis on nonlinear optical phenomena. For example, a significant accomplishment write-up describes...Millimeter-Wave Array Components Tatsuo Itoh A number of novel solid state devices such as metal semiconductor field effect transistors (MESFET

The Application of Deterministic Spectral Domain Method to the Analysis of Planar Circuit Discontinuities on Open Substrates

DTIC Science & Technology

1990-08-01

the spectral domain is extended to include the effects of two-dimensional, two-component current flow in planar transmission line discontinuities 6n...PROFESSOR: Tatsuo Itoh A deterministic formulation of the method of moments carried out in the spectral domain is extended to include the effects of...two-dimensional, two- component current flow in planar transmission line discontinuities on open substrates. The method includes the effects of space

On the suitability of the Thellier method of palaeointensity determinations on pseudo-single-domain and multidomain grains

NASA Astrophysics Data System (ADS)

Shcherbakov, V. P.; Shcherbakova, V. V.

2001-07-01

We report an experimental and theoretical study of non-linear Arai-Nagata diagrams for samples containing pseudo-single-domain (PSD) and multidomain (MD) magnetite. Our aim is to reveal the physical reasons for the deviation of these plots from ideal straight lines. Contrary to expectations, the concavity of the Arai-Nagata diagrams is not related to the two most noticeable violations of the Thellier laws documented for non-single-domain particles: the tail of partial thermoremanence and the dependence of the magnitude of pTRM on the thermal history of the sample. Indeed, the contributions from these two factors mutually cancel each other. Phenomenologically, the non-linear Arai-Nagata plots occur because samples during low-temperature stages of the Thellier procedure lose too much remanence and recover too little of it. The excessive loss of the previously imparted total TRM is due at least partly to some partial demagnetization of high-temperature TRM components and to progressive stabilization of domain structure during the repetitive heatings to moderate temperatures that form the basis of the Thellier procedure. For natural MD samples a linear fit to the low-temperature data points on the Arai-Nagata plots leads to a palaeointensity overestimated by as much as 60 per cent. The samples containing hydrothermally grown or crushed and sieved MD magnetite provide low-temperature apparent palaeointensities two to three times larger than the correct value. For small PSD samples the overestimate is less than 10-20 per cent and, in general, PSD samples can be used for the palaeointensity determinations.

Reconstructing the Geomagnetic Field in West Africa: First Absolute Intensity Results from Burkina Faso

NASA Astrophysics Data System (ADS)

Kapper, Lisa; Donadini, Fabio; Serneels, Vincent; Tema, Evdokia; Goguitchaichvili, Avto; Julio Morales, Juan

2017-03-01

We present absolute geomagnetic intensities from iron smelting furnaces discovered at the metallurgical site of Korsimoro, Burkina Faso. Up to now, archaeologists recognized four different types of furnaces based on different construction methods, which were related to four subsequent time periods. Additionally, radiocarbon ages obtained from charcoal confine the studied furnaces to ages ranging from 700-1700 AD, in good agreement with the archaeologically determined time periods for each type of furnace. Archaeointensity results reveal three main groups of Arai diagrams. The first two groups contain specimens with either linear Arai diagrams, or slightly curved diagrams or two phases of magnetization. The third group encompasses specimens with strong zigzag or curvature in their Arai diagrams. Specimens of the first two groups were accepted after applying selection criteria to guarantee the high quality of the results. Our data compared to palaeosecular variation curves show a similar decreasing trend between 900-1500 AD. However, they reveal larger amplitudes at around 800 AD and 1650 AD than the reference curves and geomagnetic field models. Furthermore, they agree well with archaeomagnetic data from Mali and Senegal around 800 AD and with volcanic data around 1700 AD.

Reconstructing the Geomagnetic Field in West Africa: First Absolute Intensity Results from Burkina Faso

PubMed Central

Kapper, Lisa; Donadini, Fabio; Serneels, Vincent; Tema, Evdokia; Goguitchaichvili, Avto; Julio Morales, Juan

2017-01-01

We present absolute geomagnetic intensities from iron smelting furnaces discovered at the metallurgical site of Korsimoro, Burkina Faso. Up to now, archaeologists recognized four different types of furnaces based on different construction methods, which were related to four subsequent time periods. Additionally, radiocarbon ages obtained from charcoal confine the studied furnaces to ages ranging from 700–1700 AD, in good agreement with the archaeologically determined time periods for each type of furnace. Archaeointensity results reveal three main groups of Arai diagrams. The first two groups contain specimens with either linear Arai diagrams, or slightly curved diagrams or two phases of magnetization. The third group encompasses specimens with strong zigzag or curvature in their Arai diagrams. Specimens of the first two groups were accepted after applying selection criteria to guarantee the high quality of the results. Our data compared to palaeosecular variation curves show a similar decreasing trend between 900–1500 AD. However, they reveal larger amplitudes at around 800 AD and 1650 AD than the reference curves and geomagnetic field models. Furthermore, they agree well with archaeomagnetic data from Mali and Senegal around 800 AD and with volcanic data around 1700 AD. PMID:28350006

Synthesis of Si Nanowires for an Anode Material of Li Batteries

DTIC Science & Technology

2007-12-04

Zhou, H. Li, H.P. Sun , D.P. Yu, Y.Q. Wang, X.J. Huang, L.Q. Chen, Z. Zhang, Appl. Phys. Lett. 75 (16) (1999) 2447 6. A.M. Wilson, B.M. Way, J.R. Dahn...Y. Liu, Electrochem. Commun. 5 (2003) 165 12. Tatsuo Umeno, Kenji Fukuda, Hongyu Wang, Nikolay Dimov, Takashi Iwao, Masaki Yoshio, Chem. Lett...Hansu Kim, Junghee Choi, Hun-Joon Sohn and Tak Kang, J. Electrochem. Soc. 146 (12) (1999) 4401 18. G.X. Wang, L. Sun , D.H. Bradhurst, S. Zhong, S.X. Dou

Effect of static pressure on absolute paleointensity recording with implications for meteorites

NASA Astrophysics Data System (ADS)

Volk, Michael W. R.; Gilder, Stuart A.

2016-08-01

We investigated the influence of hydrostatic and nonhydrostatic stress on the recording process of magnetic field intensity with particular relevance for meteorites that experienced pressures lower than 5 GPa corresponding to the lowest shock stage classification (S1) in meteorites. Thermal remanent magnetizations were imparted on natural obsidian samples containing pseudo-single domain titanomagnetite, analogous to some achondritic meteorites. Thellier-type paleointensity experiments were carried out at ambient conditions after pressure cycling to 0.6, 1.2, and 1.8 GPa. Each experiment used 10 samples to assess reproducibility, which is better than ±5%. The recorded paleointensity decreased 10%/GPa under hydrostatic stress and 20%/GPa under nonhydrostatic stress, leading to the fundamental conclusion that paleointensity results from meteorites may be appreciably underestimated. Pressure cycling shifts the blocking and unblocking spectra, thereby producing more linear slopes on an Arai diagram with increasing strain. We explain why, for samples with a single magnetization component that does not alter, a two-step paleointensity protocol sufficiently resolves the true paleointensity. Moreover, we propose that pressure cycling of pseudo-single domain bearing samples will remove the inherent curvature of the Arai slope, thereby allowing one to obtain a more accurate estimate of the true paleointensity. This likely also holds true for samples possessing multidomain grains. Conversely, linear trends on Arai plots in meteorites might have their origin in a pressure effect that does not necessarily reflect the ubiquitous presence of single domain particles.

Pressure demagnetization - a potential approach to improve successfulabsolute paleointensity experiments

NASA Astrophysics Data System (ADS)

Volk, M.; Gilder, S.

2016-12-01

Natural rocks rarely consist of ideal single-domain grains but rather contain mixtures of larger, non-ideal magnetic recorders (pseudo single PSD and multidomain grains MD), which often lead to non-linear trends on an Arai diagram. Here we present results using pressure demagnetization as a way to improve the quality of paleointensity determinations using the Coe modified Thellier method. Experiments were conducted on thermally stable obsidian containing titanomagnetite grains within the PSD range. A thermal remanent magnetization (TRM) in a 35 μT magnetic field was imparted on 20 specimens. Thellier-type paleointensity experiments were carried out at ambient conditions and after pressure cycling to 0.6, 1.2 and 1.8 GPa. Unpressurized samples yielded concave up Arai diagrams that underestimated paleointensities by 10-15%. Pressure cycling under hydrostatic conditions lowered the magnetic moment of the samples by 10%/GPa, yet produced more linear Arai plots. Normalizing the data with the initial, pre-compressed NRM value resulted in corrected paleointensity values of 35.7 ± 0.6, 35.3 ± 0.8 and 35.5 ± 0.9 μT after pressure cycling to 0.6, 1.2 and 1.8 GPa. Furthermore, the mean quality factors increased from 27 to 34, 47 and 47 for the pressure runs at 0.6, 1.2 and 1.8 GPa, respectively. These results suggest that pressure cycling preferentially demagnetizes the remanence held by PSD and MD grains, while leaving the remanence held by SD grains largely intact, leading to much greater retention rates and accuracy of paleointensity data.

National Program for Inspection of Non-Federal Dams. Highland Lakes-Lower Lake Dam (MA 00598), Connecticut River Basin, Goshen, Massachusetts. Phase I Inspection Report.

DTIC Science & Technology

1981-08-01

approval. CARNEY M. TERZLAN, KDIBER Design Branch Engineering Division Water\\ontrol Brancr%.J Engineering Division ARAiQAST MANTESI, CHIRA Geotechnical...issued to Hayden, Harding & Buchanan, Inc. on 26 June 1981 by William E. Hodgson Jr., Colonel, Corps of Engineers. Contract No. DACW 33-80-C-0006 has been

Computational Video for Collaborative Applications

DTIC Science & Technology

2003-03-01

Plenoptic Modeling: An Image- Based Rendering System.” SIGGRAPH 95, 39-46. [18] McMillan, L. An Image-Based Approach to Three-Dimensional Computer... Plenoptic modeling and rendering from image sequences taken by hand-held camera. Proc. DAGM 99, pages 94–101. [8] Y. Horry, K. Anjyo, and K. Arai

Highlighting the history of Japanese radio astronomy. 4: early solar research in Osaka

NASA Astrophysics Data System (ADS)

Orchiston, Wayne; Nakamura, Tsuko; Ishiguro, Masato

2016-12-01

For about two years, from late 1949, Minoru Oda and Tatsuo Takakura carried out solar observations from Osaka, initially with a hand-made horn and later with a small parabolic antenna connected to a 3.3 GHz receiver, but they only published one short paper on this work. At about the same time, Ojio and others at Osaka City University presented the concept of a solar grating array at a meeting of the Japan Physical Society, but this was never built. In this paper, we provide brief biographical accounts of Oda and Takakura before examining their radio telescopes and the observations that they made. We also briefly discuss the proposed Japanese solar grating array.

Use of Satellite Imagery to Monitor the Oasis Agriculture in the Turpan Depression, Xinjiang Uygur Autonomous Region, People’s Republic of China--A Case Study.

DTIC Science & Technology

1981-05-01

drops at its lowest point to 154 meters below sea level and presents a varied natural panorama of desert, oasis, gorges and sand dunes. The chief...Febr’iarv each :ear AraiKawa. Ab’ . -. 25 Thermal conditions in the depression are similar to those in North China, but the amount of precipitation is

The Brain Tourniquet: Physiological Isolation of Brain Regions Damaged by Traumatic Head Injury

DTIC Science & Technology

2008-06-19

brain slices were treated after injury with either a nootropic agent ( aniracetam , cyclothiazide, IDRA 21, or 1-BCP) or the antiepileptic drug...tourniquet approach. Four well-known nootropic agents were evaluated: aniracetam , a pyrrolidione analog that slows non-NMDA (AMPA/kainate) receptor...to improve cognition in rats [Stdubli et al., 1994], and has more potent effects than aniracetam in rat brain slices [Arai et al., 1994]. In

Testing paleointensity determinations on recent lava flows and scorias from Miyakejima, Japan

NASA Astrophysics Data System (ADS)

Fukuma, K.

2013-12-01

Still no consensus has been reached on paleointensity method. Even the classical Thellier method has not been fully tested on recent lava flows with known geomagnetic field intensity based on a systematic sampling scheme. In this study, Thellier method was applied for 1983, 1962 and 1940 basaltic lava flows and scorias from Miyakejima, Japan. Several vertical lava sections and quenched scorias, which are quite variable in magnetic mineralogy and grain size, provide an unparalleled opportunity to test paleointensity methods. Thellier experiments were conducted on a completely automated three-component spinner magnetometer with thermal demagnetizer 'tspin'. Specimens were heated in air, applied laboratory field was 45 microT, and pTRM checks were performed at every two heating steps. Curie points and hysteresis properties were obtained on small fragments removed from cylindrical specimens. For lava flows sigmoidal curves were commonly observed on the Arai diagrams. Especially the interior part of lava flows always revealed sigmoidal patterns and sometimes resulted in erroneously blurred behaviors. The directions after zero-field heating were not necessarily stable in the course of the Thellier experiments. It was very difficult, for the interior part, to ascertain linear segments on Arai diagrams corresponding to the geomagnetic field intensity at the eruption. Upper and lower clinker samples also generally revealed sigmoidal or upward concave curves on Arai diagrams. Neither lower nor higher temperature portions of the sigmoids or concaves gave the expected geomagnetic field intensities. However, there were two exceptional cases of lava flows giving correct field intensities: upper clinkers with relatively low unblocking temperatures (< 400 deg.C) and lower clinkers with broad unblocking temperature ranges from room temperature to 600 deg.C. A most promising target for paleointensity experiments within the volcanic rocks is scoria. Scoria samples always carry single

1997 Technical Digest Series. Volume 9: Quantum Optoelectronics

DTIC Science & Technology

1997-03-01

Program Co-Chair Shigehisa Arai, Tokyo Institute of Technology, Japan Yasuhiko Arakawa, University of Tokyo, Japan Israel Bar-Joseph, Weizmann...assembly formed quantum dot active layers, (p. 3) 2:30pm (Invited) QWA3 • Optical probing of mesoscopic and nano-structures, Yasuhiko Arakawa, Univ...80, 3466 (1996). 6/QWA3-1 Optical Probing of Mesoscopic and Nano-Structures Yasuhiko Arakawa University of Tokyo, Japan We investigate the

Weathering Tests on Protective Helmets Approved to Australian Standard AS 1698 (for Vehicle Users).

DTIC Science & Technology

1979-11-01

Expanded Polystyrene HELMETI Colour Production; SAA Size ,Length Width j Mass Circumference Date Serial No. cm imm mm nu qm nun L A White July 󈨒 B535336...HELMET DETAILS Make: ARAI Model: S-75 Shell: Fibreglass Reinforced Polyester Resin Liner: Expanded Polystyrene HELMET Colour Production SAA Size...Reinforced Polyester Resin Liner; Expanded Polystyrene (with thin plastic inner shell) HELMET Colour Production’ SAA Size Length Width Mass

Analysis of Neural Systems Involved in Modulation of Memory Storage

DTIC Science & Technology

1990-01-01

modulating effects of oxotremorine and scopolomine (a cholinergic agonist and antagonist, respec- tively) are blocked by lesions of the ST (Introini-Collison...Introini-Collison, I.B., Arai, Y. and McGaugh, J.L. Stria terminalis lesions attenuate the effects of posttraining oxotremorine and atropine on reten- tion...McGaugh, J.L. and Izquierdo, I. Amnesia induced by short-term treatment with ethanol: Attenuation by pre-test oxotremorine . Pharmacol- ogy

IGARSS 1989: Canadian Symposium on Remote Sensing (12th) (Symposium Canadien sur la Teledetection): Quantitative Remote Sensing: An Economic Tool for the Nineties Held in Vancouver, Canada on 10-14 July 1989. Volume 4. Thursday, July 13

DTIC Science & Technology

1989-07-14

Ahern, Canada Centre for Remote Sensing, Canada Kohel Arai, National Space Development Agency of Japan, Japan F. Bonn, Universitie de Sherbrooke...Catholilque de Louvain, Belgium D.C. Hogg, University of Colorado, USA R. Humphreys, MacDonald Dettwiler Associates, Canada E. Jull, University of...to quantitative 1990 assessment of landslide damage ,4 ( C V ’ ) C.H. Trotter, P.R. Stephens, N.R. Trustrum, M.J. Page, K.S. Carr, R.C. de Rose

Defining the Molecular Actions of Dietary Fatty Acids in Breast Cancer: Selective Modulation of Peroxisome Proliferator-Activated Receptor Gamma. Addendum

DTIC Science & Technology

2008-05-01

0.05 significance threshold. Fol- owing ANOVA, Fisher’s least significant difference, LSD , air-wise comparison was implemented post-hoc. Briefly, the SD...average absolute difference etween any two groups was greater than the LSD critical alue, then the pair-wise comparison for those two groups ere...Xu, Y., Hin- shaw , J.C., Zimmerman, G.A., Hama, K., Aoki, J., Arai, H., Prestwich, G.D., 2003. Identification of an intracellular receptor for

Absolute paleointensity results from the Equator and the Pliocene-Pleistocene dipole field

NASA Astrophysics Data System (ADS)

Wang, H.; Kent, D. V.

2013-12-01

The current geomagnetic field (GMF) of the Earth is mostly geocentric dipolar with intensities in polar regions (~60 μT) about twice as high as in equatorial regions (~30 μT). However, Lawrence et al. [2009] found that the 0-5 Ma average paleointensity from 41 lava flow sites in Antarctica (~78°S) was only 31.5 μT. We present absolute paleointensity results from lava flows of similar age (0-3 Ma) from the Galapagos Islands located within 1°S of the Equator using a recently developed multidomain (MD) correction technique [Wang and Kent, 2013] on fresh subsets of the same samples that were recently analyzed for PSV [Kent, Wang & Rochette, 2010]. After standard Thellier series paleointensity experiments, we gave the samples total thermal remanent magnetizations (tTRM) by cooling from their Curie point in the presence of a laboratory-applied field (15 μT). We then repeated the paleointensity experiment on each sample, with the laboratory-applied tTRM as a synthetic natural remanent magnetization (NRM), using the same laboratory-applied field and temperature steps to obtain a synthetic Arai signature, which should only represent the domain-state dependent properties of the sample. We corrected the Arai diagrams from the original paleointensity experiment by using the Arai signatures from the repeated experiment, which neutralizes the typical MD concave-up Arai effect. We experimented on 3 specimens from each of 51 lava sites, 29 of which gave acceptable paleointensity results from one or more specimen(s). The average paleointensity of the 29 successful lava flow sites is ~29 μT (~23 μT for geometric mean). In these 29 sites, 12 of them are of normal polarity, yielding an average paleointensity of ~32 μT (geometric mean ~24 μT), and 17 of them are of reverse polarity, yielding an average paleointensity of ~27 μT (geometric mean ~23 μT). Mean paleomagnetic directions of the normal and reverse polarity sites are statistically antipodal and within a few degrees

Defining the Molecular Actions of Dietary Fatty Acids in Breast Cancer: Selective Modulation of Peroxisome Proliferator-Activated Receptor Gamma

DTIC Science & Technology

2006-12-01

hypothesis testing (ANOVA) using icrosoft Excel v10.0 atα= 0.05 significance threshold. Fol- owing ANOVA, Fisher’s least significant difference, LSD , air...critical value (α= 0.05) ound in the t distribution. If the average absolute difference etween any two groups was greater than the LSD critical alue...cIntyre, T.M., Pontsler, A.V., Silva, A.R., St Hilaire, A., Xu, Y., Hin- shaw , J.C., Zimmerman, G.A., Hama, K., Aoki, J., Arai, H., Prestwich, G.D

The properties of Q-deformed hyperbolic and trigonometric functions in quantum deformation

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

Deta, U. A., E-mail: utamaalan@yahoo.co.id, E-mail: utamadeta@unesa.ac.id; Suparmi

2015-09-30

Quantum deformation has been studied due to its relation with applications in nuclear physics, conformal field theory, and statistical-quantum theory. The q-deformation of hyperbolic function was introduced by Arai. The application of q-deformed functions has been widely used in quantum mechanics. The properties of this two kinds of system explained in this paper including their derivative. The graph of q-deformed functions presented using Matlab. The special case is given for modified Poschl-Teller plus q-deformed Scarf II trigonometry potentials.

Compositional Evidence for Launch Pairing of the YQ and Elephant Moraine Lunar Meteorites

NASA Technical Reports Server (NTRS)

Korotev, R. L.; Jollitt, B. L.; Zeigler, R. A.; Haskin, L. A.

2003-01-01

Arai and Warren provide convincing evidence that QUE (Queen Alexandra Range) 94281 derives from the same regolith as Y (Yamato) 793274 and, therefore, that the two meteorites were likely ejected from the Moon by the same impact. Recently discovered Y981031 is paired with Y793274. The "YQ" meteorites (Y793274/Y981031 and QUE 94281 are unique among lunar meteorites in being regolith breccias composed of subequal amounts of mare volcanic material (a VLT [very-low-Ti] basalt or gabbro) and feldspathic highland material. EET (Elephant Moraine) 87521 and its pair EET 96008 are fragmental breccias composed mainly of VLT basalt or gabbro. Warren, Arai, and colleagues note that the volcanic components of the YQ and EET meteorites are texturally similar more similar to each other than either is to mare basalts of the Apollo collection. Warren and colleagues address the issue of possible launch pairing of YQ and EET, but note compositional differences between EET and the volcanic component of YQ, as inferred from extrapolations of regressions to high FeO concentration. We show here that: (1) EET 87/96 consists of fragments of a differentiated magma body, (2) subsamples of EET represent a mixing trend between Fe-rich and Mg-rich differentiates, and (3) the inferred volcanic component of YQ is consistent with a point on the EET mixing line. Thus, there is no compositional impediment to the hypothesis that YQ is launch paired with EET.

Conceptural Study of Gyroscopic Damping Systems for Structural Indentification

NASA Astrophysics Data System (ADS)

Furuya, H.; Senba, A.

2002-01-01

the system by using the response amplitude, and for the optimum momentum inertia by using the natural frequency. References [1] Hiroshi FURUYA, Masanori TAKAHASHI, and Tatsuo OHMACHI: Concept of Adaptive Gyroscopic Damper and Vibration Suppression of Flexible Structures, 8th International Conference on Adaptive Structures and Technologies, Wakayama, Oct. 29-31, 1997, eds. Y. Murotsu, C.A. Rogers, P. Santini, and H. Okubo, Technomic Publishing, pp.247-254, 1998. [2] Hiroshi FURUYA, Masanori TAKAHASHI, and Tatsuo OHMACHI: Pseudo Feedback Control of Adaptive Gyroscopic Damper for Vibration Suppression, 39th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Material Conference, AIAA 98-1796, Long Beach, CA, April 20-23, pp.830-834, 1998. [3] Hiroshi FURUYA and Atsuo KOBORI: Suppression of Multiple Modes Vibration of Flexible Structures with Adaptive Gyroscopic Damper System, 10th International Conference on Adaptive Structures and Technologies, Paris, Oct. 13-15, 1999, eds. R. Ohayon, and M. Bernadou, Technomic Publishing, pp. 127-134, 1999.

PREFACE: 26th Symposium on Plasma Science for Materials (SPSM-26)

NASA Astrophysics Data System (ADS)

2014-06-01

papers that are selected via strict peer-review process from full papers submitted for the proceedings of the conference. The topics range from basic physics and chemistry of plasma processing to a broad variety of materials processing and environmental applications. This proceeding offers an overview on the recent advances in thermal and non-equilibrium plasmas as well as the challenges ahead in the field of plasma research and applications among engineers and scientists. It is an honor to present this volume of Journal of Physics: Conference Series and we deeply thank the authors for their enthusiastic and high-grade contribution. The editors hope that this proceeding will be useful and helpful for deepening our understanding of science and technology of plasma materials processing and also for stimulating further development of the plasma technology. Finally, I would like to thank the organizing committee and organizing secretariat of SPSM-26, and the participants of the conference for contribution to a successful and exciting meeting. The conference was chaired by Prof. Masaharu Shiratani, Kyushu University. I would also like to thank the financial support from The 153rd Committee on Plasma Materials Science. Editors of SPMS-26 Prof Takayuki Watanabe, Kyushu University, Japan Prof Makoto Sekine, Nagoya University, Japan Prof Takanori Ichiki, The University of Tokyo, Japan Prof Masaharu Shiratani, Kyushu University, Japan Prof Akimitsu Hatta, Kochi University of Technology, Japan Sponsors and Supporting Organization: The 153rd Committee on Plasma Materials Science, Japan Society for the Promotion of Science

Paleointensity results for 0 and 4 ka from Hawaiian lava flows: a new approach to sampling

NASA Astrophysics Data System (ADS)

Cromwell, G.; Tauxe, L.; Staudigel, H.; Ron, H.; Trusdell, F.

2012-04-01

Paleointensity data are typically generated from core samples drilled out of the massive parts of lava flows. During Thellier-Thellier type experiments, these massive samples suffer from very low success rates (~20%), as shown by failure to meet statistical criteria. Low success generally occurs for two reasons: 1) alteration of the sample during the heating process, and 2) multi-domain behavior of massive material. Moreover, recent studies of historical lava flows show that massive samples may not accurately reflect the intensity of the magnetic field even when they are successful (Valet et al., 2010). Alternatively, submarine basaltic glasses (SBG) produce high success rates (~80%) for Thellier-Thellier type experiments, likely due to near instantaneous cooling rates which produce single-domain magnetic grains. In addition, SBG have been proven to produce accurate records of the magnetic field (e.g., Pick and Tauxe, 1993). In this study we investigate the success of paleointensity experiments on subaerial quenched basalts from Hawaii in the quest for single domain, rapidly cooled subaerial analogs to SBG. We also examine the effects of grain size and cooling rate on the accuracy of paleointensity results. During March 2011, we collected samples from 31 dated lava flows (0-3800 BP), including the historical 1950 C.E. and 2010 C.E. flows. Each lava flow was additionally subsampled when unique cooling structures within the unit could be identified. Single-domain, rapidly quenched glasses from the 1950 and 2010 flows are ideally behaved, i.e. straight Arai plots, and accurately record the expected geomagnetic field strength. However, slower cooled specimens from the same flows produce sagged Arai plots and consistently underestimate expected geomagnetic field intensity. Results from ideally behaved glasses over the last 4 ka indicate periods of rapid field change in Hawaii and a possible high intensity field spike around 2.7 ka. We will present new results from our

Thellier's Betes Noires and how to Recognize Them

NASA Astrophysics Data System (ADS)

Dunlop, D. J.

2007-12-01

When Emile Thellier invented his classic paleointensity determination method, he made it quite clear that it applied only to NRMs which had originated as TRMs carried by non-interacting single-domain grains. Baked clays and bricks satisfied his stringent requirements but volcanic rocks were tested and rejected as unsuitable. While most paleomagnetists would regard Thellier's stance as unduly rigid, it certainly would help improve the usual dismal success rate in paleointensity studies if at the outset one could recognize and discard Thellierś betes noires: (1) NRMs of non-TRM origin, such as CRMs and TCRMs, which are particularly insidious because they may yield linear Arai plots with the wrong slope; (2) interacting grains, which compromise the independence of non-overlapping pTRMs; (3) grains larger than single-domain size with non-reciprocal blocking and unblocking. Pre-screening based on physical mechanisms would also be an improvement compared to relying solely on reliability parameters and checks. These are effective in detecting laboratory alteration of a rock but less so in filtering out samples which behave reversibly, yet are flawed recorders of the paleofield. FORC diagrams combine analysis of coercivity distribution, strength of interactions, and basic domain state. Their effectiveness in weeding out magnetic deviants has been demonstrated by Carvallo et al. (JGR 111, B12103, 2006). However, the CRM/TCRM problem remains severe. Almost all CRMs measured by Draeger et al. (GJI 166, 12-32, 2006) had ideal Arai plots but field intensity values were in error by as much as a factor 2. Unfortunately CRM/TCRM is not easily diagnosed in individual samples, and we are driven to reconsider Thellier's dictum: don't take risks by using rocks whose NRM could be other than TRM. Unfortunately this includes many attractive candidates, volcanic glasses, baked contacts and most metamorphic rocks among them. A crude approach might be to reject those samples in a

Convection, buoyancy or endolymph expansion: what is the actual mechanism responsible for the caloric response of semicircular canals?

PubMed

Valli, Paulo; Buizza, Angelo; Botta, Laura; Zucca, Giampiero; Ghezzi, Luciano; Valli, Stefano

The mechanisms underlying caloric nystagmus are still matter of debate. The original theory proposed by Barany and more recently by Pau and Limberg suggested that convective endolymphatic currents were involved. In contrast Gentine et al. suggested that the main mechanism responsible for caloric nystagmus is buoyancy due to calorization of the endolymph, without the need of continuous convective currents. Finally, other authors (Scherer and Clarke, Arai et al.) proposed that thermal expansion or contraction of the endolymph were involved. In the present study experimental conditions have been considered able to discriminate between these different models. The experiments, were carried out on isolated labyrinth preparations of the frog. Only the predictions of the model based on buoyancy were fully consistent with the experimental results whereas those provided by the other models were not.

Nova Sco 2016 No. 2 = PNV J17225112-3158349 = ASASSN-16kd

NASA Astrophysics Data System (ADS)

Waagen, Elizabeth O.

2016-09-01

AAVSO Alert Notice 550 announces the independent discovery of Nova Sco 2016 No. 2 = ASASSN-16kd = PNV J17225112-3158349 = V1656 Sco by Shigehisa Fujikawa (Kan'onji, Kagawa, Japan) at unfiltered CCD magnitude 11.6 on 2016 September 06.481 UT; and by ASAS-SN (Stanek et al., ATel #9469) at 12.13 V on 2016 September 06.00 UT. Spectroscopy indicating that Nova Sco 2016 No. 2 is a highly reddened classical Fe II-type nova was obtained by Arai and Honda (CBET 4320); by Bohlsen (ATel #9477); by Bersier et al. (ATel #9478); and by Prieto et al. (ATel #9479). Finder charts with sequence may be created using the AAVSO Variable Star Plotter (https://www.aavso.org/vsp). Observations should be submitted to the AAVSO International Database. See full Alert Notice for more details.

A field like today's? The strength of the geomagnetic field 1.1 billion years ago

NASA Astrophysics Data System (ADS)

Sprain, Courtney J.; Swanson-Hysell, Nicholas L.; Fairchild, Luke M.; Gaastra, Kevin

2018-06-01

Palaeomagnetic data from ancient rocks are one of the few types of observational data that can be brought to bear on the long-term evolution of Earth's core. A recent compilation of palaeointensity estimates from throughout Earth history has been interpreted to indicate that Earth's magnetic field strength increased in the Mesoproterozoic (between 1.5 and 1.0 billion years ago), with this increase taken to mark the onset of inner core nucleation. However, much of the data within the Precambrian palaeointensity database are from Thellier-style experiments with non-ideal behaviour that manifests in results such as double-slope Arai plots. Choices made when interpreting these data may significantly change conclusions about long-term trends in the intensity of Earth's geomagnetic field. In this study, we present new palaeointensity results from volcanics of the ˜1.1-billion-year-old North American Midcontinent Rift. While most of the results exhibit non-ideal double-slope or sagging behaviour in Arai plots, some flows have more ideal single-slope behaviour leading to palaeointensity estimates that may be some of the best constraints on the strength of Earth's field for this time. Taken together, new and previously published palaeointensity data from the Midcontinent Rift yield a median field strength estimate of 56.0 ZAm2—very similar to the median for the past 300 Myr. These field strength estimates are distinctly higher than those for the preceding billion years (Ga) after excluding ca. 1.3 Ga data that may be biased by non-ideal behaviour—consistent with an increase in field strength in the late Mesoproterozoic. However, given that ˜90 per cent of palaeointensity estimates from 1.1 to 0.5 Ga come from the Midcontinent Rift, it is difficult to evaluate whether these high values relative to those estimated for the preceding billion years are the result of a stepwise, sustained increase in dipole moment. Regardless, palaeointensity estimates from the Midcontinent

A field like today's? The strength of the geomagnetic field 1.1 billion years ago

NASA Astrophysics Data System (ADS)

Sprain, Courtney J.; Swanson-Hysell, Nicholas L.; Fairchild, Luke M.; Gaastra, Kevin

2018-02-01

Paleomagnetic data from ancient rocks are one of the few types of observational data that can be brought to be bear on the long-term evolution of Earth's core. A recent compilation of paleointensity estimates from throughout Earth history has been interpreted to indicate that Earth's magnetic field strength increased in the Mesoproterozoic (between 1.5 and 1.0 billion years ago), with this increase taken to mark the onset of inner core nucleation. However, much of the data within the Precambrian paleointensity database are from Thellier-style experiments with non-ideal behavior that manifests in results such as double-slope Arai plots. Choices made when interpreting these data may significantly change conclusions about long-term trends in the intensity of Earth's geomagnetic field. In this study, we present new paleointensity results from volcanics of the ˜1.1 billion-year-old North American Midcontinent Rift. While most of the results exhibit non-ideal double-slope or sagging behavior in Arai plots, some flows have more ideal single-slope behavior leading to paleointensity estimates that may be some of the best constraints on the strength of Earth's field for this time. Taken together, new and previously published paleointensity data from the Midcontinent Rift yield a median field strength estimate of 56.0 ZAm2—very similar to the median for the past 300 million years. These field strength estimates are distinctly higher than those for the preceding billion years after excluding ca. 1.3 Ga data that may be biased by non-ideal behavior—consistent with an increase in field strength in the late Mesoproterozoic. However, given that ˜90 per cent of paleointensity estimates from 1.1 to 0.5 Ga come from the Midcontinent Rift, it is difficult to evaluate whether these high values relative to those estimated for the preceding billion years are the result of a stepwise, sustained increase in dipole moment. Regardless, paleointensity estimates from the Midcontinent

Rock Magnetic Studies and Absolute Paleointensity Determination of the Dacite of the Duffer Formation of the Pilbara Craton, Australia

NASA Astrophysics Data System (ADS)

Herrero-Bervera, E.; Mojzsis, S. J.

2009-12-01

We have conducted a rock magnetic and absolute paleointensity determination of the red dacite of the Duffer Formation of the Pilbara craton, Australia. The age of the dated rock unit is 3452 Ma +/-16 Ma. Vector analyses of step-wise alternating field (NRM up to 100 mT) and thermal demagnetization (from NRM up to 650 o C) results yield three components of magnetization. Curie point determinations indicate three characteristic temperatures, one at 280 o C, a second one at 358 o C and a third one at 630 o C. Magnetic grain-size experiments were performed on small specimens with a variable field translation balance (VFTB). The coercivity of remanence (Hcr) suggests that the NRM is carried by high-coercivity grains that is more likely carried from a hematite fraction as is also shown by the high-temperature component with blocking temperatures above 450{o}C and up to at least 640 o C. The ratios of the hysteresis parameters plotted as a Day diagram show that most grain sizes are scattered within the PSD and MD domain ranges. In addition to the rock magnetic experiments we have performed absolute paleointensity experiments on the samples using the modified Thellier-Coe double heating method to determine the paleointensities. pTRM checks were performed systematically to document magnetomineralogical changes during heating. The temperature was incremented by steps of 50 o C between room temperature and 590 o^ C. The paleointensity determinations were obtained from the slope of Arai diagrams. Special care was taken to interpret the Arai diagrams within the same range lower than 300 o C unless a clear and unique slope was present. Our paleointensity results indicate that the paleofield obtained was 6.5 micro-Teslas from a high temperature component ranging from 450 to 590 o^ C that has been interpreted to be the oldest magnetization yet recorded in paleomagnetic studies of the Duffer Formation. This primary high temperature component establishes the existence of the

Structural changes and shallow geological structure of the isolated basins in the forearc slope of the Japan Trench

NASA Astrophysics Data System (ADS)

Misawa, A.; Arai, K.; Fujiwara, T.; Sato, M.; Shin'ichiro, Y.; Hirata, K.; Kanamatsu, T.

2017-12-01

On the forearc slope of the Japan Trench is a typical subsidence region associated with the subduction erosion in the Japan Trench. Arai et al. (2014) reported the existence of the isolated basins with widths of up to several tens of kilometers using the seismic profiles that acquired before the 2011 Tohoku earthquake (Mw 9.0) in the forearc slope. The isolated basin probably formed due to subsidence accompanying the regional activity of normal fault systems in the forearc slope. Arai et al. (2014) suggested that the geological structures of the forearc slope along the Japan Trench are typical of those resulting from subduction erosion and proposed that the episodic subsidence accompanied by normal faulting is the most recent deformation. During the 2011 large earthquake, seafloor on the landward slope of the Japan Trench moved 50 m east-southeast toward trench (Fujiwara et al., 2011). In addition, aftershock activity after the 2011 large earthquake have predominated in the activity of the normal fault system. Therefore, there have a possibility that new isolated basin is formed after the 2011 large earthquake in the forearc slope of the Japan Trench. In order to capture the structural change in the isolated basins, we compared the seismic profiles acquired before (Multi-Channel Seismic (MCS) data acquired with KR07-05 cruise) and after (Single-Channel Seismic (SCS) data acquired with NT15-07 cruise) the 2011 large earthquake. However, the large-scale structural changes are not identified around the isolated basin. In order to capture the small-scale structural change in the shallow part of the isolated basins using high-resolution data, we make an attempt at the marine geological and geophysical survey in the offshore Tohoku region using R/V Shinsei-Maru of JAMSTEC (KS-17-8 cruise) in August 2017. In this cruise, we plan to carry out the following surveys; (1) swath bathymetric survey, (2) high-resolution parametric subbottom profiler (SBP) survey, (3) geomagnetic

Lessons from natural and artificial polyploids in higher plants.

PubMed

Hegarty, M; Coate, J; Sherman-Broyles, S; Abbott, R; Hiscock, S; Doyle, J

2013-01-01

Polyploidy in higher plants is a major source of genetic novelty upon which selection may act to drive evolution, as evidenced by the widespread success of polyploid species in the wild. However, research into the effects of polyploidy can be confounded by the entanglement of several processes: genome duplication, hybridisation (allopolyploidy is frequent in plants) and subsequent evolution. The discovery of the chemical agent colchicine, which can be used to produce artificial polyploids on demand, has enabled scientists to unravel these threads and understand the complex genomic changes involved in each. We present here an overview of lessons learnt from studies of natural and artificial polyploids, and from comparisons between the 2, covering basic cellular and metabolic consequences through to alterations in epigenetic gene regulation, together with 2 in-depth case studies in Senecio and Glycine. See also the sister article focusing on animals by Arai and Fujimoto in this themed issue. Copyright © 2013 S. Karger AG, Basel.

Biaxial Creep Specimen Fabrication

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

JL Bump; RF Luther

This report documents the results of the weld development and abbreviated weld qualification efforts performed by Pacific Northwest National Laboratory (PNNL) for refractory metal and superalloy biaxial creep specimens. Biaxial creep specimens were to be assembled, electron beam welded, laser-seal welded, and pressurized at PNNL for both in-pile (JOYO reactor, O-arai, Japan) and out-of-pile creep testing. The objective of this test campaign was to evaluate the creep behavior of primary cladding and structural alloys under consideration for the Prometheus space reactor. PNNL successfully developed electron beam weld parameters for six of these materials prior to the termination of the Navalmore » Reactors program effort to deliver a space reactor for Project Prometheus. These materials were FS-85, ASTAR-811C, T-111, Alloy 617, Haynes 230, and Nirnonic PE16. Early termination of the NR space program precluded the development of laser welding parameters for post-pressurization seal weldments.« less

High Temperature, Controlled-Atmosphere Aerodynamic Levitation Experiments with Applications in Planetary Science

NASA Astrophysics Data System (ADS)

Macris, C. A.; Badro, J.; Eiler, J. M.; Stolper, E. M.

2016-12-01

The aerodynamic levitation laser apparatus is an instrument in which spherical samples are freely floated on top of a stream of gas while being heated with a CO2laser to temperatures up to about 3500 °C. Laser heated samples, ranging in size from 0.5 to 3.5 mm diameter, can be levitated in a variety of chemically active or inert atmospheres in a gas-mixing chamber (e.g., Hennet et al. 2006; Pack et al. 2010). This allows for containerless, controlled-atmosphere, high temperature experiments with potential for applications in earth and planetary science. A relatively new technique, aerodynamic levitation has been used mostly for studies of the physical properties of liquids at high temperatures (Kohara et al. 2011), crystallization behavior of silicates and oxides (Arai et al. 2004), and to prepare glasses from compositions known to crystallize upon quenching (Tangeman et al. 2001). More recently, however, aerodynamic levitation with laser heating has been used as an experimental technique to simulate planetary processes. Pack et al. (2010) used levitation and melting experiments to simulate chondrule formation by using Ar-H2 as the flow gas, thus imposing a reducing atmosphere, resulting in reduction of FeO, Fe2O3, and NiO to metal alloys. Macris et al. (2015) used laser heating with aerodynamic levitation to reproduce the textures and diffusion profiles of major and minor elements observed in impact ejecta from the Australasian strewn field, by melting a powdered natural tektite mixed with 60-100 μm quartz grains on a flow of pure Ar gas. These experiments resulted in quantitative modeling of Si and Al diffusion, which allowed for interpretations regarding the thermal histories of natural tektites and their interactions with the surrounding impact vapor plume. Future experiments will employ gas mixing (CO, CO2, H2, O, Ar) in a controlled atmosphere levitation chamber to explore the range of fO2applicable to melt-forming impacts on other rocky planetary bodies

Magnetic Properties and Absolute Paleointensity of Upper Oceanic Crust Generated by Superfast Seafloor Spreading, ODP Leg 209.

NASA Astrophysics Data System (ADS)

Herrero-Bervera, E.; Acton, G.

2005-12-01

We investigate the magnetic mineralogy and absolute paleointensity of oceanic basalt samples from Hole 1256D, cored during Ocean Drilling Program (ODP) Leg 206. Hole 1256D is located on the Cocos Plate about 5 km east of the transition zone between marine magnetic anomalies 5Bn.2n and 5Br (~15 Ma). During Leg 206, the hole penetrated 502 m into basalts of the upper oceanic crust that was generated by superfast seafloor spreading (>200 mm/yr) along the East Pacific Rise. Rock magnetic investigations included continuous low field (k-T) thermomagnetic analyses, alternating field (AF) and thermal demagnetization, optical microscopy, saturation isothermal remanent magnetization (SIRM), and magnetic grain size analyses. Following the removal of a drilling overprint, AF and thermal demagnetization paths for most samples decay linearly to the origin on orthogonal vector end point diagrams, suggesting that a stable characteristic remanent magnetization component can be resolved. Optical microscopy and k-T (Curie points) identified titanomagnetites and titanomaghemites as the main magnetic carriers and grain size studies indicate that the carriers are either single domain (SD) and/or pseudosingle domain (PSD) in nature. Using the modified Thellier-Coe double heating method, we determined absolute paleointensity determinations for 51 specimens sampled from different ``stratigraphic'' levels of the core. pTRM checks were performed systematically one temperature step down the last pTRM acquisition in order to document magnetomineralogical changes during heating. The temperature was incremented by steps of 50°C between room temperature and 500°C and every 25-30°C for higher temperatures. The paleointensity determinations were obtained from the slope of the Arai diagrams. Special care was taken to interpret the Arai diagrams within the same range of temperatures lower than 300°C unless a clear and unique slope was present over a higher range of temperatures. Only about 10

Paleointensity of the 1.3 Ga Gardar Basalts, Southern Greenland

NASA Astrophysics Data System (ADS)

Carnes, L. K.; Kodama, K. P.

2017-12-01

Biggin et al. (2015) suggest that inner core nucleation (ICN) may have occurred 1.3 Ga based on Thomas's (1993) high paleointensity result for the Gardar Basalts in the Eriksfjord Formation of southern Greenland (VDMs up to 150 ZAm2). However, this result has been found to contradict the timing of ICN from recent thermal evolution models and modern paleointensity studies from nearly coeval rocks. We sampled the Gardar Basalts to conduct a modern paleointensity study to check the results of the Thomas (1993) study. We report results from a Thellier-Thellier experiment on 106 Gardar basalt samples collected from 39 flows using the IZZI protocol with pTRM and tail checks. Hysteresis measurements and FORC diagrams indicate that pseudo-single domain magnetite (Curie temperature of 580° C based on χ vs T) is the dominant magnetic mineral in the basalts. Low-temperature demagnetization (LTD) did not improve the paleointensity results so standard measurements of heating in a nitrogen controlled atmosphere are reported here. Thomas (1993) only interpreted his paleointensity results up to 450˚C and found a steep slope in the Arai plots indicating a high paleointensity. Heating at temperatures up to the Curie point showed a second component of magnetization and two slope behavior on the Arai plots with the high temperature results showing lower paleointensities. Between temperatures of 520-580 °C, good results were found for 35 samples yielding an average paleointensity of 5.02±4.32 μT. Thermal demagnetization yielded a mean direction for these flows of D=276.5˚, I=18.9˚, K=11.0, N=33. Based on the paleolatitude from the NRM measurements, an average virtual dipole moment (VDM) of 13.2 ± 11.3 ZAm2 was obtained for 19 of the Gardar flows based on 35 sample measurements. The best results came from the lower flow sequence far from the Illímaussaq intrusion. These VDMs are significantly lower than the previously published Gardar Basalt paleointensity results, suggesting

V5588 SGR = Nova Sagittarii 2011 No. 2 = Pnv J18102135-2305306

NASA Astrophysics Data System (ADS)

Waagen, Elizabeth O.

2011-04-01

Announces the discovery of Nova Sgr 2011 No. 2 = V5588 SGR = PNV J18102135-2305306 by Koichi Nishiyama (Kurume, Japan) and Fujio Kabashima (Miyaki, Japan) on ~ 2011 March 27.832 UT at unfiltered CCD magnitude mag 11.7. Spectra obtained by A. Arai, M. Nagashima, T. Kajikawa, and C. Naka (Koyama Astronomical Observatory, Kyoto Sangyo University) on Mar. 28.725 UT suggest that the object is a classical nova reddened by interstellar matter. The object was designated PNV J18102135-2305306 when posted on the Central Bureau's Transient Objects Confirmation Page (TOCP) webpage. E. Kazarovets, on behalf of the GCVS team, reports that the name V5588 Sgr has been assigned to this nova. It was nitially announced in CBET 2679 (Daniel W. E. Green, ed.) and AAVSO Special Notice #237 (Waagen). Additional information published in IAU Circular 9203 (Green, ed.). Finder charts with sequence may be created using the AAVSO Variable Star Plotter (http://www.aavso.org/vsp). Observations should be submitted to the AAVSO International Database. See full Alert Notice for more details and observations.

Nova Scorpii 2011 = PNV J16551100-3838120

NASA Astrophysics Data System (ADS)

Waagen, Elizabeth O.

2011-06-01

Announces the discovery of Nova Scorpii 2011 = PNV J16551100-3838120 by John Seach (Chatsworth Island, NSW, Australia) on 2011 June 1.40 UT at magnitude 9.5 (DSLR + orange filter). Spectra by Bernard Heathcote (South Yarra, Vic, Australia) on Jun 2.4896 UT, A. Arai, T. Kajikawa, and M. Nagashima (Kyoto Sangyo University, Japan) on 2011 June 2.68 UT, and Masayuki Yamanaka and Ryosuke Itoh (Hiroshima University, Japan) on Jun 2 UT indicate a highly-reddened classical nova. Initially reported to the AAVSO by Seach and announced in AAVSO Special Notice #240 (Arne Henden) and IAU CBET 2735 (Daniel W. E. Green, ed.). The object was designated PNV J18102135-2305306 when posted on the Central Bureau's Transient Objects Confirmation Page (TOCP) webpage. Finder charts with sequence may be created using the AAVSO Variable Star Plotter (http://www.aavso.org/vsp). Observations should be submitted to the AAVSO International Database. See full Alert Notice for more details, observations, and links to images. [Nova Sco 2011 subsequently assigned the name V1312 Sco

New archaeomagnetic data recovered from the study of celtiberic remains from central Spain (Numantia and Ciadueña, 3rd-1st centuries BC). Implications on the fidelity of the Iberian paleointensity database

NASA Astrophysics Data System (ADS)

Osete, M. L.; Chauvin, A.; Catanzariti, G.; Jimeno, A.; Campuzano, S. A.; Benito-Batanero, J. P.; Tabernero-Galán, C.; Roperch, P.

2016-11-01

Variations of geomagnetic field in the Iberian Peninsula prior to roman times are poorly constrained. Here we report new archaeomagnetic results from four ceramic collections and two combustion structures recovered in two pre-roman (celtiberic) archaeological sites in central Spain. The studied materials have been dated by archaeological evidences and supported by five radiocarbon dates. Rock magnetic experiments indicate that the characteristic remanent manetization (ChRM) is carried by a low coercivity magnetic phase with Curie temperatures of 530-575 °C, most likely Ti-poor titanomagnetite/titanomaghemite. Archaeointensity determinations were carried out by using the classical Thellier-Thellier protocol including tests and corrections for magnetic anisotropy and cooling rate dependency. Two magnetic behaviours were depicted during the laboratory treatment. Black potsherds and poor heated samples from the kilns, presented two magnetization components, alterations or curved Arai plots and were therefore rejected. In contrast, well heated specimens (red ceramic fragments and well heated samples from the kilns) show one single well defined component of magnetization going through the origin and linear Arai plots providing successful archaeointensity determinations. The effect of anisotropy of the thermoremanent magnetization (ATRM) on paleointensity analysis was systematically investigated obtaining very high ATRM corrections on fine pottery specimens. In some cases, differences between the uncorrected and ATRM corrected paleointensity values reached up to 86 %. The mean intensity values obtained from three selected set of samples were 64.3 ± 5.8 μT; 56.8 ± 3.8 and 56.7 ± 4.6 μT (NUS2, CI2 and CIA, respectively), which contribute to better understand the evolution of the palaeofield intensity in central Iberia during the 3rd-1st centuries BC. The direction of the field at first century BC has also been determined from oriented samples from CIA kilns (D = 357

Experimental and numerical simulation of the acquisition of chemical remanent magnetization and the Thellier procedure

NASA Astrophysics Data System (ADS)

Shcherbakov, V. P.; Sycheva, N. K.; Gribov, S. K.

2017-09-01

The results of the Thellier-Coe experiments on paleointensity determination on the samples which contain chemical remanent magnetization (CRM) created by thermal annealing of titanomagnetites are reported. The results of the experiments are compared with the theoretical notions. For this purpose, Monte Carlo simulation of the process of CRM acquisition in the system of single-domain interacting particles was carried out; the paleointensity determination method based on the Thellier-Coe procedure was modeled; and the degree of paleointensity underestimation was quantitatively estimated based on the experimental data and on the numerical results. Both the experimental investigations and computer modeling suggest the following main conclusion: all the Arai-Nagata diagrams for CRM in the high-temperature area (in some cases up to the Curie temperature T c) contain a relatively long quasi-linear interval on which it is possible to estimate the slope coefficient k and, therefore, the paleointensity. Hence, if chemical magnetization (or remagnetization) took place in the course of the magnetomineralogical transformations of titanomagnetite- bearing igneous rocks during long-lasting cooling or during repeated heatings, it can lead to incorrect results in determining the intensity of the geomagnetic field in the geological past.

Growth of cyanobacteria on Martian Regolith Simulant after exposure to vacuum

NASA Astrophysics Data System (ADS)

Arai, Mayumi; Sato, Seigo; Ohmori, Masayuki; Tomita-Yokotani, Kaori; Hashimoto, Hirofumi; Yamashita, Masamichi

Habitation on Mars is one of our challenges in this century. The growth of cyanobacteria on Martian Regolith Simulant (MRS) was studied with two species of terrestrial cyanobacteria, Nostoc, and one species of other cyanobacterium, Synechosystis. Their vacuum tolerances was examined in order to judge feasibility of the use of cyanobacteria to creat habitable environment on a distant planet. The viability of cyanobacteria tested was evaluated by the microscopic observation after staining by FDA (fluorescein diacetate). A part of them were also re-incubated again in a liquid culture medium, and viability and the chlorophyll production were examined in detail. Nostoc was found to grow for over 140 days with their having normal function of chlorophyll synthesis on the MRS. After the exposure to high vacuum environment (10-5 Pa) for a year, Nostoc sp. started growth. Chlorophyll was produced after this vacuum exposure as well. The A'MED (Arai's Mars Ecosystem Dome, A'MED) is designed to install on Mars for conducting agricultural production in it. We performed the fundamental experiment with MRS. These results show a possibility that cyanobacteria could adapt to MRS, and grow under the low pressure environment expected on Mars.

Nova Sagittarii 2014 = PNV J18250860-2236024 AND Erratum

NASA Astrophysics Data System (ADS)

Waagen, Elizabeth O.

2014-02-01

Details of discovery of Nova Sagittarii 2014 (PNV J18250860-2236024) and procedures for observing and reporting observations are announced. Discovered by Sigeru Furuyama (Tone-machi, Ibaraki-ken, Japan) andreported by S. Nakano (Sumoto, Japan) at unfiltered CCD magnitude 8.7 on 2014 Jan. 26.857 UT. Coordinates: R.A. 18 25 08.60 Decl. = -22 36 02.4 (2000.0). Nova Sgr 2014 is Fe II-type classical nova past maximum, per low-resolution spectra obtained by A. Arai on 2014 Jan. 30.87 UT. Announced in IAU CBAT CBET 3802 (D. W. E. Green, ed.). Finder charts with sequence may be created using the AAVSO Variable Star Plotter (http://www.aavso.org/vsp). Observations should be submitted to the AAVSO International Database. See full Alert Notice for more details and observations. Also, an Erratum is reported. In AAVSO Alert Notice 496, Mati Morel (MMAT, Thornton, NSW, Australia) was credited with the discovery of the 1989 outburst of V745 Sco. The discoverer was William Liller (LIW, Vina del Mar, Chile), who observed V745 Sco on 1989 July 30.08 UT at magnitude 9.7 (PROBLICOM discovery using 2415 film with orange filter).

Nova Sco 2011 No. 2 = PNV J16364440-4132340 = PNV J16364300-4132460

NASA Astrophysics Data System (ADS)

Waagen, Elizabeth O.

2011-09-01

Announcement of discovery of Nova Sco 2011 No. 2 = PNV J16364440-4132340 = PNV J16364300-4132460. Discovered independently by John Seach (Chatsworth Island, NSW, Australia, on 2011 Sep. 06.37 UT at mag=9.8 (DSLR)) and by Yuji Nakamura (Kameyama, Mie, Japan, on 2011 Sep. 06.4313 UT at mag=9.7 C (CCD)). Posted on the IAU Central Bureau for Astronomical Telegrams Transient Object Confirmation Page (TOCP) as PNV J16364440-4132340 (Nakamura) and PNV J16364300-4132460 (Seach); identifications consolidated in VSX under PNV J16364440-4132340. Spectra obtained by A. Arai et al. on 2011 Sep. 7.42 UT suggest a highly reddened Fe II-type classical nova. Spectra by F. Walter and J. Seron obtained Sep. 2011 8.091 UT confirm a young galactic nova; they report spectra are reminiscent of an early recurrent nova. Initially announced in AAVSO Special Notice #251 (Matthew Templeton) and IAU Central Bureau Electronic Telegram 2813 (Daniel W. E. Green, ed.). Finder charts with sequence may be created using the AAVSO Variable Star Plotter (http://www.aavso.org/vsp). Observations should be submitted to the AAVSO International Database. See full Alert Notice for more details and observations.

Absolute Paleointensity Study of Halawa Excursion (ca. 2.514+/- 0.039 Ma) Recorded on Koolau Volcano at Halawa, Oahu, Hawaii.

NASA Astrophysics Data System (ADS)

Lau, J. K.; Herrero-Bervera, E.

2006-12-01

of the Arai diagrams. Special care was taken to interpret the Arai diagrams within the same range of temperatures lower than 300°C unless a clear and unique slope would be present. Our paleointensity results indicate a near-zero reduced strength of the field during the excursional period ranging from 5 to 9 micro-Tesla but high absolute paleointensity values prior to the excursional lavas The corresponding VGPs are located off the southeast part of Africa, close to Madagascar. The 40Ar/39Ar incremental heating experiments on groundmass from nine flow-sites located at different stratigraphic levels yielded an isochron age of 2.514+/-0.039 Ma indicating that the excursion may correlate with the C2r.2r-l Cryptochron of Cande and Kent [1995].

Spot Reading of the Absolute Paleointensity of the Geomagnetic Field During the Kiaman Superchron: The Exeter Lavas Case

NASA Astrophysics Data System (ADS)

Herrero-Bervera, E.; Fuller, M. D.

2004-12-01

It is well known that Superchrons provide an opportunity to study the geomagnetic field in an extreme state, i.e. when reversals are at their lowest frequency or totally absent. Such Superchrons represent features that may provide constraints for theoretical calculations and numerical models of the geodynamo. Thus, one way to contribute to the understanding of the generation of the paleofield particularly during Superchrons is to determine the absolute paleointensity of rocks formed during those periods of time. We have sampled a member of the Exeter lavas (ca 290.8+/-0.8 Ma, Ar/Ar date) from the large, abandoned quarry in the northeastern slope of the southernmost hill of Killerton Park, 10 km northeast of Exeter where we collected three samples from three different stratigraphic levels. We stepwise demagnetized the samples collected from the three different levels by both alternating field (5mT to 100mT) and thermal (from 28oC to 575-650o C) methods, and the mean directions obtained by principal component analysis (D=198o and I=-25o). All samples yielded a strong and stable ChRM trending towards the origin based on no less than seven to nine steps, with thermal and AF results agreeing to a very high degree. Low field susceptibility versus temperature (k-T) analyses were conducted for individual samples and the majority of them show reversible curves. Curie point determinations revealed a temperature close to or equal to 580o C, indicative of almost pure magnetite for most of the samples. Magnetic grain sizes analysis indicated SD-PSD sizes. We used the modified Thellier-Coe double heating method to determine paleointensities. pTRM checks were performed systematically one temperature step down the last pTRM acquisition in order to document magnetomineralogical changes during heating. The temperature was incremented by steps of 50o C between room temperature and 500oC and every 25-30o C. The paleointensity determinations were obtained from the slope of the Arai

Restricted T cell receptor repertoire in CLL-like monoclonal B cell lymphocytosis and early stage CLL.

PubMed

Blanco, Gonzalo; Vardi, Anna; Puiggros, Anna; Gómez-Llonín, Andrea; Muro, Manuel; Rodríguez-Rivera, María; Stalika, Evangelia; Abella, Eugenia; Gimeno, Eva; López-Sánchez, Manuela; Senín, Alicia; Calvo, Xavier; Abrisqueta, Pau; Bosch, Francesc; Ferrer, Ana; Stamatopoulos, Kostas; Espinet, Blanca

2018-01-01

Analysis of the T cell receptor (TR) repertoire of chronic lymphocytic leukemia-like monoclonal B cell lymphocytosis (CLL-like MBL) and early stage CLL is relevant for understanding the dynamic interaction of expanded B cell clones with bystander T cells. Here we profiled the T cell receptor β chain (TRB) repertoire of the CD4 + and CD8 + T cell fractions from 16 CLL-like MBL and 13 untreated, Binet stage A/Rai stage 0 CLL patients using subcloning analysis followed by Sanger sequencing. The T cell subpopulations of both MBL and early stage CLL harbored restricted TRB gene repertoire, with CD4 + T cell clonal expansions whose frequency followed the numerical increase of clonal B cells. Longitudinal analysis in MBL cases revealed clonal persistence, alluding to persistent antigen stimulation. In addition, the identification of shared clonotypes among different MBL/early stage CLL cases pointed towards selection of the T cell clones by common antigenic elements. T cell clonotypes previously described in viral infections and immune disorders were also detected. Altogether, our findings evidence that antigen-mediated TR restriction occurs early in clonal evolution leading to CLL and may further increase together with B cell clonal expansion, possibly suggesting that the T cell selecting antigens are tumor-related.

A New Interface for the Magnetics Information Consortium (MagIC) Paleo and Rock Magnetic Database

NASA Astrophysics Data System (ADS)

Jarboe, N.; Minnett, R.; Koppers, A. A. P.; Tauxe, L.; Constable, C.; Shaar, R.; Jonestrask, L.

2014-12-01

The Magnetic Information Consortium (MagIC) database (http://earthref.org/MagIC/) continues to improve the ease of uploading data, the creation of complex searches, data visualization, and data downloads for the paleomagnetic, geomagnetic, and rock magnetic communities. Data uploading has been simplified and no longer requires the use of the Excel SmartBook interface. Instead, properly formatted MagIC text files can be dragged-and-dropped onto an HTML 5 web interface. Data can be uploaded one table at a time to facilitate ease of uploading and data error checking is done online on the whole dataset at once instead of incrementally in an Excel Console. Searching the database has improved with the addition of more sophisticated search parameters and with the ability to use them in complex combinations. Searches may also be saved as permanent URLs for easy reference or for use as a citation in a publication. Data visualization plots (ARAI, equal area, demagnetization, Zijderveld, etc.) are presented with the data when appropriate to aid the user in understanding the dataset. Data from the MagIC database may be downloaded from individual contributions or from online searches for offline use and analysis in the tab delimited MagIC text file format. With input from the paleomagnetic, geomagnetic, and rock magnetic communities, the MagIC database will continue to improve as a data warehouse and resource.

Vehicular pollution modeling using the operational street pollution model (OSPM) for Chembur, Mumbai (India).

PubMed

Kumar, Awkash; Ketzel, Matthias; Patil, Rashmi S; Dikshit, Anil Kumar; Hertel, Ole

2016-06-01

Megacities in India such as Mumbai and Delhi are among the most polluted places in the world. In the present study, the widely used operational street pollution model (OSPM) is applied for assessing pollutant loads in the street canyons of Chembur, a suburban area just outside Mumbai city. Chembur is both industrialized and highly congested with vehicles. There are six major street canyons in this area, for which modeling has been carried out for NOx and particulate matter (PM). The vehicle emission factors for Indian cities have been developed by Automotive Research Association of India (ARAI) for PM, not specifically for PM10 or PM2.5. The model has been applied for 4 days of winter season and for the whole year to see the difference of effect of meteorology. The urban background concentrations have been obtained from an air quality monitoring station. Results have been compared with measured concentrations from the routine monitoring performed in Mumbai. NOx emissions originate mainly from vehicles which are ground-level sources and are emitting close to where people live. Therefore, those emissions are highly relevant. The modeled NOx concentration compared satisfactorily with observed data. However, this was not the case for PM, most likely because the emission inventory did not contain emission terms due to resuspended particulate matter.

Glassy and Metastable Crystalline BaTi2O5 by Containerless Processing

NASA Astrophysics Data System (ADS)

Yoda, Shinichi; Kentei Yu, Yu; Kumar, Vijaya; Kameko, Masashi

metastable a-and b-BaTi2 O5 are constructed with non-centrosymmetric geometry TiO5 polyhedra, which provides higher potential for yielding high dielectric constants, pyroelectric and nonlinear op-tical properties than that of normal 4-or 6-coordinate Ti-O polyhedra. In addition, all lanthanide elements can be doped into the unusual glassy BaTi2 O5 structure to open up new possibilities for creating new bulk glasses, metastable phases and nano-crystalline ceramics with peculiar electronic and optical properties, such as giant permittivity and strong upconversion luminescence. References [1] Y. Akishige, K. Fukano, and H. Shigematsu, Jpn. J. Appl. Phys. p2, 42, L946 (2003). [2] J. Yu, Y. Arai, T. Masaki, T. Ishikawa, S. Yoda, S. Kohara, H. Taniguchi, M. Itoh, and Y. Kuroiwa, Chem. Matter. 18 p.2169 (2006) [3] J. Yu, S. Kohara, S. Nozawa, K. Itoh, S. Miyoshi, Y. Arai, A. Masuno, H. Taniguchi, M. Itoh, M. Takata, T. Fukunaga, S. Koshihara, Y. Kuroiwa, and S. Yoda, Chem. Matter. 21, p259 (2009).

An autosomal recessive mutation in SCL24A4 causing enamel hypoplasia in Samoyed and its relationship to breed-wide genetic diversity.

PubMed

Pedersen, Niels C; Shope, Bonnie; Liu, Hongwei

2017-01-01

Pure breeding of dogs has led to over 700 heritable disorders, of which almost 300 are Mendelian in nature. Seventy percent of the characterized mutations have an autosomal recessive mode of inheritance, indicative of positive selection during bouts of inbreeding primarily for new desired conformational traits. Samoyed suffer from several common complex genetic disorders, but up to this time only two X-linked and one autosomal dominant disorder have been identified. Previous studies based on pedigrees and SNP arrays have concluded that Samoyed breeders have done a good job in maintaining genetic diversity and avoiding excessive inbreeding. This may explain why autosomal recessive disorders have not occurred to the extent observed in many other breeds. However, an enamel hypoplasia analogous to a form of autosomal recessive amelogenesis imperfecta (ARAI) in humans has been recently characterized in Samoyed, although the causative mutation appears to have existed for three or more decades. The rise of such a mutation indicates that bouts of inbreeding for desired conformational traits are still occurring despite an old and well-defined breed standard. Therefore, the present study has two objectives: 1) measure genetic diversity in the breed using DNA and short tandem repeats (STR), and 2) identify the exact mutation responsible for enamel hypoplasia in the breed, possible explanations for its recent spread, and the effect of eliminating the mutation on existing genetic diversity. The recent discovery of an autosomal recessive amelogenesis imperfecta (ARAI) in Samoyed provides an opportunity to study the mutation as well as genetic factors that favored its occurrence and subsequent spread. The first step in the study was to use 33 short tandem repeat (STR) loci on 25/38 autosomes and seven STRs across the dog leukocyte antigen (DLA) class I and II regions on CFA12 to determine the DNA-based genetic profile of 182 individuals from North America, Europe and Australia

NASA Rocket Experiment Finds the Universe Brighter Than We Thought

NASA Image and Video Library

2017-12-08

A NASA sounding rocket experiment has detected a surprising surplus of infrared light in the dark space between galaxies, a diffuse cosmic glow as bright as all known galaxies combined. The glow is thought to be from orphaned stars flung out of galaxies. The findings redefine what scientists think of as galaxies. Galaxies may not have a set boundary of stars, but instead stretch out to great distances, forming a vast, interconnected sea of stars. Observations from the Cosmic Infrared Background Experiment, or CIBER, are helping settle a debate on whether this background infrared light in the universe, previously detected by NASA’s Spitzer Space Telescope, comes from these streams of stripped stars too distant to be seen individually, or alternatively from the first galaxies to form in the universe. This is a time-lapse photograph of the Cosmic Infrared Background Experiment (CIBER) rocket launch, taken from NASA's Wallops Flight Facility in Virginia in 2013. The image is from the last of four launches. Read more: www.nasa.gov/press/2014/november/nasa-rocket-experiment-f... Image Credit: T. Arai/University of Tokyo NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Improvements to the Magnetics Information Consortium (MagIC) Paleo and Rock Magnetic Database

NASA Astrophysics Data System (ADS)

Jarboe, N.; Minnett, R.; Tauxe, L.; Koppers, A. A. P.; Constable, C.; Jonestrask, L.

2015-12-01

The Magnetic Information Consortium (MagIC) database (http://earthref.org/MagIC/) continues to improve the ease of data uploading and editing, the creation of complex searches, data visualization, and data downloads for the paleomagnetic, geomagnetic, and rock magnetic communities. Online data editing is now available and the need for proprietary spreadsheet software is therefore entirely negated. The data owner can change values in the database or delete entries through an HTML 5 web interface that resembles typical spreadsheets in behavior and uses. Additive uploading now allows for additions to data sets to be uploaded with a simple drag and drop interface. Searching the database has improved with the addition of more sophisticated search parameters and with the facility to use them in complex combinations. A comprehensive summary view of a search result has been added for increased quick data comprehension while a raw data view is available if one desires to see all data columns as stored in the database. Data visualization plots (ARAI, equal area, demagnetization, Zijderveld, etc.) are presented with the data when appropriate to aid the user in understanding the dataset. MagIC data associated with individual contributions or from online searches may be downloaded in the tab delimited MagIC text file format for susbsequent offline use and analysis. With input from the paleomagnetic, geomagnetic, and rock magnetic communities, the MagIC database will continue to improve as a data warehouse and resource.

Development of a Self-Consistent Model of Plutonium Sorption: Quantification of Sorption Enthalpy and Ligand-Promoted Dissolution

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

Powell, Brian; Kaplan, Daniel I; Arai, Yuji

2016-12-29

This university lead SBR project is a collaboration lead by Dr. Brian Powell (Clemson University) with co-principal investigators Dan Kaplan (Savannah River National Laboratory), Yuji Arai (presently at the University of Illinois), Udo Becker (U of Michigan) and Rod Ewing (presently at Stanford University). Hypothesis: The underlying hypothesis of this work is that strong interactions of plutonium with mineral surfaces are due to formation of inner sphere complexes with a limited number of high-energy surface sites, which results in sorption hysteresis where Pu(IV) is the predominant sorbed oxidation state. The energetic favorability of the Pu(IV) surface complex is strongly influencedmore » by positive sorption entropies, which are mechanistically driven by displacement of solvating water molecules from the actinide and mineral surface during sorption. Objectives: The overarching objective of this work is to examine Pu(IV) and Pu(V) sorption to pure metal (oxyhydr)oxide minerals and sediments using variable temperature batch sorption, X-ray absorption spectroscopy, electron microscopy, and quantum-mechanical and empirical-potential calculations. The data will be compiled into a self-consistent surface complexation model. The novelty of this effort lies largely in the manner the information from these measurements and calculations will be combined into a model that will be used to evaluate the thermodynamics of plutonium sorption reactions as well as predict sorption of plutonium to sediments from DOE sites using a component additivity approach.« less

On-road assessment of light duty vehicles in Delhi city: Emission factors of CO, CO2 and NOX

NASA Astrophysics Data System (ADS)

Jaiprakash; Habib, Gazala

2018-02-01

This study presents the technology based emission factors of gaseous pollutants (CO, CO2, and NOX) measured during on-road operation of nine passenger cars of diesel, gasoline, and compressed natural gas (CNG). The emissions from two 3-wheelers, and three 2-wheelers were measured by putting the vehicles on jacks and operating them according to Modified Indian Driving Cycle (MIDC) at no load condition. The emission factors observed in the present work were significantly higher than values reported from dynamometer study by Automotive Research Association of India (ARAI). Low CO (0.34 ± 0.08 g km-1) and high NOX (1.0 ± 0.4 g km-1) emission factors were observed for diesel passenger cars, oppositely high CO (2.2 ± 2.6 g km-1) and low NOX (1.0 ± 1.6 g km-1) emission factors were seen for gasoline powered cars. The after-treatment technology in diesel vehicles was effective in CO reduction. While the use of turbocharger in diesel vehicles to generate high combustion temperature and pressure produces more NOx, probably which may not be effectively controlled by after-treatment device. The after-treatment devices in gasoline powered Post-2010, Post-2005 vehicles can be acclaimed for reduced CO emissions compared to Post-2000 vehicles. This work presents a limited data set of emission factors from on-road operations of light duty vehicles, this limitation can be improved by further measurements of emissions from similar vehicles.

Comparison between two methods for forward calculation of ambient noise H/V spectral ratios

NASA Astrophysics Data System (ADS)

Garcia-Jerez, A.; Luzón, F.; Sanchez-Sesma, F. J.; Santoyo, M. A.; Albarello, D.; Lunedei, E.; Campillo, M.; Iturrarán-Viveros, U.

2011-12-01

The analysis of horizontal-to-vertical spectral ratios of ambient noise (NHVSR) is a valuable tool for seismic prospecting, particularly if both a dense spatial sampling and a low-cost procedure are required. Unfortunately, the computation method still lacks of a unanimously accepted theoretical basis and different approaches are currently being used for inversion of the ground structure from the measured H/V curves. Two major approaches for forward calculation of NHVSRs in a layered medium are compared in this work. The first one was developed by Arai and Tokimatsu (2004) and recently improved by Albarello and Lunedei (2011). It consists of a description of the wavefield as generated by Far Surface point Forces (FSF method). The second one is based on the work of Sánchez-Sesma et al. (2011) who consider ambient noise as a Diffuse WaveField (DWF method), taking advantage of the proportionality between its Fourier-transformed autocorrelation (power spectrum) and the imaginary part of the Green function when source and receiver are the same. In both methods, the NHVSR is written as (PH/PV)1/2, where PH and PV are the horizontal and vertical power spectra. In the FSF method these quantities are given by PV∝⊙m(1+1/2χm2α2)(ARm/kRm)2 PH∝⊙m{(1+1/2χm2α2)(ARm/kRm)2χm2+1/2α2(ALm/kLm)2} where kRm, χm and ARm are wavenumber, ellipticity and medium response of the m-th Rayleigh wave mode; kLm and ALm correspond to the m-th Love wave mode and α is the horizontal-to-vertical load ratio of the ambient noise sources. Some common factors are omitted in the expressions of PV and PH. On the other hand, the DWF method deals with the full wavefield including both surface and body waves. In order to make the comparison easier, and taking into account that surface waves are often the dominant components in wide spectral ranges, body wave contributions are neglected here. In this case, the PH and PV power spectra for the DWF method are reduced to the simple expressions: PV

Volcanic Record of the Halawa Excursion (ca 2.514+/-0.039 Ma), Koolau Volcano, Oahu Hawaii, USA: Full Vector Analyses

NASA Astrophysics Data System (ADS)

Lau, J.; Herrero-Bervera, E.

2007-05-01

sampled. We used the modified Thellier-Coe double heating method to determine paleointensities. pTRM checks were performed systematically one temperature step down the last pTRM acquisition in order to document magnetomineralogical changes during heating. The temperature was incremented by steps of 50°C between room temperature and 500°C and every 25-30°C. The paleointensity determinations were obtained from the slope of the Arai diagrams. Special care was taken to interpret the Arai diagrams within the same range of temperatures lower than 300°C unless a clear and unique slope would be present. Our paleointensity results indicate a near-zero reduced strength of the field during the excursional period ranging from 5 to 9 micro-Tesla. The corresponding VGPs are located off the southeast part of Africa, close to Madagascar. 40Ar/39Ar incremental heating experiments on groundmass from nine flow-sites located at different stratigraphic levels yielded isochron ages ranging from 2.64+/-0.25 to 2.40+/-0.46 Ma indicating that the excursion may correlate with the C2r.2r-l Cryptochron of Cande and Kent [1995]. This is potentially the first terrestrial record of the ca. 2.514 +/- 0.039 Ma Cryptochron, a finding that will place important constraints on evolution of the entire Koolau shield edifice also.

Full Vector Analyses of Cryptochron C2r.2r-l (ca. 2.42-2.44 Ma) Recorded on Koolau Volcano at Halawa, Oahu, Hawaii: Evidence From Directions, Absolute Paleointensity Determinations and 40Ar/39Ar Studies.

NASA Astrophysics Data System (ADS)

Browne, E. J.; Herrero-Bervera, E.; Singer, B.

2005-12-01

sampled. We used the modified Thellier-Coe double heating method to determine paleointensities. pTRM checks were performed systematically one temperature step down the last pTRM acquisition in order to document magnetomineralogical changes during heating. The temperature was incremented by steps of 50o C between room temperature and 500oC and every 25-30o C. The paleointensity determinations were obtained from the slope of the Arai diagrams. Special care was taken to interpret the Arai diagrams within the same range of temperatures lower than 300oC unless a clear and unique slope would be present. Our paleointensity results indicate a near-zero reduced strength of the field during the excursional period ranging from 5 to 9 micro-Tesla. The corresponding VGPs are located off the southeast part of Africa, close to Madagascar. Initial 40Ar/39Ar incremental heating experiments on groundmass from nine flow-sites located at different stratigraphic levels yielded isochron ages ranging from 2.64+/-0.25 to 2.40+/-0.46 Ma indicating that the excursion may correlate with the C2r.2r-l Cryptochron of Cande and Kent [1995]. this is potentially the first terrestrial record of the ca. 2.4 Ma Cryptochron, a finding that will place important constraints on evolution of the entire Koolau shield edifice also.

Impact of the Great East Japan Earthquake on Regional Obstetrical Care in Miyagi Prefecture.

PubMed

Sugawara, Junichi; Hoshiai, Tetsuro; Sato, Kazuyo; Tokunaga, Hideki; Nishigori, Hidekazu; Arai, Takanari; Okamura, Kunihiro; Yaegashi, Nobuo

2016-06-01

The authors report the results of surveys on the emergency transport or evacuation status of obstetric patients conducted in Miyagi prefecture, one of the major disaster areas of the Great East Japan Earthquake and tsunami. The surveys examined the damages to maternity institutions, evacuation status and transport of pregnant women, and prehospital childbirths and were conducted in 50 maternity institutions and 12 fire departments in Miyagi. Two coastal institutions were destroyed completely, and four institutions were destroyed partially by the tsunami, forcing them to stop medical services. In the two-month period after the disaster, 217 pregnant women received hospital transport or gave birth after evacuation. Satisfactory perinatal outcomes were maintained. Emergency obstetric transport increased to approximately 1.4 fold the number before the disaster. Twenty-three women had prehospital childbirths, indicating a marked increase to approximately three times the number of the previous year. In the acute phase of the tsunami disaster, maternity institutions were damaged severely and perinatal transport was not possible; as a result, pregnant women inevitably gave birth in unplanned institutions, and the number of prehospital births was increased extremely. To obtain satisfactory obstetric outcomes, it is necessary to construct a future disaster management system and to re-recognize pregnant women as people with special needs in disaster situations. Sugawara J , Hoshiai T , Sato K , Tokunaga H , Nishigori H , Arai T , Okamura K , Yaegashi N . Impact of the Great East Japan Earthquake on regional obstetrical care in Miyagi Prefecture. Prehosp Disaster Med. 2016;31(3):255- 258.

Paleomagnetism and petrophysics of the Jänisjärvi impact structure, Russian Karelia

NASA Astrophysics Data System (ADS)

Salminen, J.; Donadini, F.; Pesonen, L. J.; Masaitis, V. L.; Naumov, M. V.

Paleomagnetic, rock magnetic, and petrophysical results are presented for impactites and target rocks from the Lake Jänisjärvi impact structure, Russian Karelia. The impactites (tagamites, suevites, and lithic breccias) are characterized by increased porosity and magnetization, which is in agreement with observations performed at other impact structures. Thermomagnetic, hysteresis, and scanning electron microscope (SEM) analysis document the presence of primary multidomain titanomagnetite with additional secondary titanomaghemite and ilmenohematite. The characteristic impact-related remanent magnetization (ChRM) direction (D = 101.5°, I = 73.1°, α95 = 6.2°) yields a pole (Lat. = 45.0°N, Long. = 76.9°E, dp = 9.9°, dm = 11.0°). Additionally, the same component is observed as an overprint on some rocks located in the vicinity of the structure, which provides proofs of its primary origin.An attempt was made to determine the ancient geomagnetic field intensity. Seven reliable results were obtained, yielding an ancient intensity of 68.7 ± 7.6 μT (corresponding to VDM of 10.3 ± 1.1 × 1022 Am2). The intensity, however, appears to be biased toward high values mainly because of the concave shape of the Arai diagrams.The new paleomagnetic data and published isotopic ages for the structure are in disagreement. According to well-defined paleomagnetic data, two possible ages for magnetization of Jänisjärvi rocks exist: 1) Late Sveconorwegian age (900-850 Myr) or 2) Late Cambrian age (˜500 Myr). However, published isotopic ages are 718 ± 5 Myr (K-Ar) and 698 ± 22 Myr (39Ar-40Ar), but such isotopic dating methods are often ambiguous for the impactites.

Priming of Early Closure: Evidence for the Lexical Boost during Sentence Comprehension

PubMed Central

Traxler, Matthew J.

2014-01-01

Two self-paced reading experiments investigated priming in sentences containing “early” vs. “late closure” ambiguities. Early closure sentences impose relatively large processing costs at the point of syntactic disambiguation (Frazier & Rayner, 1982). The current study investigated a possible way to reduce processing costs. Target sentences were temporarily ambiguous and were disambiguated towards either the preferred “late” closure analysis or the dispreferred “early” closure analysis. Each target sentence was preceded by a prime that was either structurally identical or that required a different syntactic analysis. In Experiment 1, all of the prime sentences shared the same critical verb as the target (Arai et al., 2007; Carminati et al., 2008; Tooley et al., 2009, in press; Traxler et al., in press; Weber & Indefrey, 2009). In Experiment 2, verb repetition was eliminated by reorganizing the stimuli from Experiment 1. In Experiment 1, processing of the disambiguating verb was facilitated when an “early” closure target sentence followed an “early” closure prime. In Experiment 2, there were no significant priming effects, although an overall difference in processing time favored “late closure” targets. Combined analyses verified that the pattern of results in Experiment 1 differed significantly from Experiment 2. These experiments provide the first indication that “early” closure analyses can be primed and that such priming is more robust when a critical verb appears in both the prime and the target sentence. The results add to the body of data indicating a “lexical boost” for syntactic priming effects during comprehension. They have implications for theories of syntactic representation and processing (e.g., Boland & Blodgett, 2006; Vosse & Kempen, 2009; Sag et al., 2003). PMID:25750915

New archaeomagnetic data recovered from the study of celtiberic remains from central Spain (Numancia and Ciadueña, III-I BC).

NASA Astrophysics Data System (ADS)

Osete, María Luisa; Chauvin, Annick; Catanzariti, Gianluca; Jimeno, Alfredo; Campuzano, Saioa A.; Benito-Batanero, Juan Pedro; Roperch, Pierrick

2016-04-01

Variation of geomagnetic field changes in the Iberian Peninsula between prior to roman times remain very poorly constrained. Here we report results from the archeomagnetic study carried out on four set of ceramics and one combustion structure recovered in two pre-roman (celtiberic) archeological sites in central Spain. Rock magnetic experiments indicate the ChRM is carried by magnetite. Archaeointensity determinations were carried out by using the classical Thellier-Thellier experiment including tests and corrections for magnetic anisotropy and magnetic cooling rate dependency. Well heated specimens (red ceramic fragments and well heated samples from the kiln) show one single well defined component of magnetisation going through the origin and a linear arai plot providing successful archaeointensity determinations. The effect of anisotropy of the termoremanent magnetization (ATRM) on paleointensity analysis was specially investigated obtaining very high ATRM corrections on fine pottery specimens. With differences between the uncorrected and ATRM corrected paleointensity values that reached up to 80-100%. Mean intensity values obtained from three selected groups were 61.1 ±5.9μT; 57.6±3.3 and 56.4± 4.7μT which allows delineate the evolution of the paleofield intensity in central Iberia during the III-I centuries BC. The new archaeointensity data disagrees with previous results from Iberian ceramics which were not corrected by the ATRM effect. But they are in agreement with the most recent French paleointensity curve and latest European intensity model. Both based on a selection of high quality paleointensity data. This result reinforces the idea that the puzzling scatter often observed in the global paleointensity database is likely due to differences in the laboratory protocol. Further data from well contrasted laboratory protocols are still necessary to delineate confidently the evolution of the geomagnetic paleofield during the first millennium BC.

Introducing a New Interface for the Online MagIC Database by Integrating Data Uploading, Searching, and Visualization

NASA Astrophysics Data System (ADS)

Jarboe, N.; Minnett, R.; Constable, C.; Koppers, A. A.; Tauxe, L.

2013-12-01

The Magnetics Information Consortium (MagIC) is dedicated to supporting the paleomagnetic, geomagnetic, and rock magnetic communities through the development and maintenance of an online database (http://earthref.org/MAGIC/), data upload and quality control, searches, data downloads, and visualization tools. While MagIC has completed importing some of the IAGA paleomagnetic databases (TRANS, PINT, PSVRL, GPMDB) and continues to import others (ARCHEO, MAGST and SECVR), further individual data uploading from the community contributes a wealth of easily-accessible rich datasets. Previously uploading of data to the MagIC database required the use of an Excel spreadsheet using either a Mac or PC. The new method of uploading data utilizes an HTML 5 web interface where the only computer requirement is a modern browser. This web interface will highlight all errors discovered in the dataset at once instead of the iterative error checking process found in the previous Excel spreadsheet data checker. As a web service, the community will always have easy access to the most up-to-date and bug free version of the data upload software. The filtering search mechanism of the MagIC database has been changed to a more intuitive system where the data from each contribution is displayed in tables similar to how the data is uploaded (http://earthref.org/MAGIC/search/). Searches themselves can be saved as a permanent URL, if desired. The saved search URL could then be used as a citation in a publication. When appropriate, plots (equal area, Zijderveld, ARAI, demagnetization, etc.) are associated with the data to give the user a quicker understanding of the underlying dataset. The MagIC database will continue to evolve to meet the needs of the paleomagnetic, geomagnetic, and rock magnetic communities.

Thellier GUI: An integrated tool for analyzing paleointensity data from Thellier-type experiments

NASA Astrophysics Data System (ADS)

Shaar, Ron; Tauxe, Lisa

2013-03-01

Thellier-type experiments are a method used to estimate the intensity of the ancient geomagnetic field from samples carrying thermoremanent magnetization. The analysis of Thellier-type experimental data is conventionally done by manually interpreting data from each specimen individually. The main limitations of this approach are: (1) manual interpretation is highly subjective and can be biased by misleading concepts, (2) the procedure is time consuming, and (3) unless the measurement data are published, the final results cannot be reproduced by readers. These issues compound when trying to combine together paleointensity data from a collection of studies. Here, we address these problems by introducing the Thellier GUI: a comprehensive tool for interpreting Thellier-type experimental data. The tool presents a graphical user interface, which allows manual interpretation of the data, but also includes two new interpretation tools: (1) Thellier Auto Interpreter: an automatic interpretation procedure based on a given set of experimental requirements, and 2) Consistency Test: a self-test for the consistency of the results assuming groups of samples that should have the same paleointensity values. We apply the new tools to data from two case studies. These demonstrate that interpretation of non-ideal Arai plots is nonunique and different selection criteria can lead to significantly different conclusions. Hence, we recommend adopting the automatic interpretation approach, as it allows a more objective interpretation, which can be easily repeated or revised by others. When the analysis is combined with a Consistency Test, the credibility of the interpretations is enhanced. We also make the case that published paleointensity studies should include the measurement data (as supplementary files or as a contributions to the MagIC database) so that results based on a particular data set can be reproduced and assessed by others.

Tabulation of comet observations.

NASA Astrophysics Data System (ADS)

1993-01-01

Concerning comets: 1973 XII Kohoutek, 1975 IX Kobayashi-Berger-Milon, 1976 VI West, 1976 XI P/d'Arrest, 1977 XIV Kohler, 1979 X Bradfield, 1980 X P/Stephan-Oterma, 1980 XV Bradfield, 1981 II Panther, 1982 VI Austin, 1983 V Sugano-Saigusa-Fujikawa, 1983 VII IRAS-Araki-Alcock, 1983 XIII P/Kopff, 1984 XIII Austin, 1984 XXIII Levy-Rudenko, 1985 XIII P/Giacobini-Zinner, 1985 XVII Hartley-Good, 1985 XIX Thiele, 1986 I P/Boethin, 1986 III P/Halley, 1986 XVIII Terasako, 1987 II Sorrells, 1987 III Nishikawa-Takamizawa-Tago, 1987 X P/Grigg-Skjellerup, 1987 XXIII Rudenko, 1987 XXIX Bradfield, 1987 XXXII McNaught, 1987 XXXIII P/Borrelly, 1988 IV Furuyama, 1988 V Liller, 1988 XIV P/Tempel 2, 1988 XV Machholz, 1988 XX Yanaka, 1988 XXIV Yanaka, 1989 X P/Brorsen-Metcalf, 1989 XV P/Schwassmann-Wachmann 1, 1989 XIX Okazaki-Levy-Rudenko, 1989 XXI Helin-Roman-Alu, 1989 XXII Aarseth-Brewington, 1990 III Černis-Kiuchi-Nakamura, 1990 VI Skorichenko-George, 1990 VIII P/Schwassmann-Wachmann 3, 1990 IX P/Peters-Hartley, 1990 X P/Wild 4, 1990 XIV P/Honda Mrkos-Pajdušáková, 1990 XVII Tsuchiya-Kiuchi, 1990 XXI P/Encke, 1990 XXVI Arai, 1991 XI P/Levy, 1991 XV P/Hartley 2, 1991 XVI P/Wirtanen, 1991 XVII P/Arend-Rigaux, 1991 XXI P/Faye, 1991 XXIII P/Shoemaker 1, 1991 XXIV Shoemaker-Levy, 1991l Helin-Lawrence, 1991ο P/Chernykh, 1991r Helin-Alu, 1991a1 Shoemaker-Levy, 1991g1 Zanotta-Brewington, 1991h1 Mueller, 1912d Tanaka-Machholz, 1992f P/Shoemaker-Levy 8, 1992k Machholz, 1992l P/Giclas, 1992p P/Brewington, 1992q Helin-Lawrence, 1992s P/Ciffréo, 1992t P/Swift-Tuttle, 1992u P/Väisälä, 1992x P/Schaumasse, 1992y Shoemaker, 1992a1 Ohshita, 1993a Mueller, P/Smirnova-Chernykh.

Repeating Deep Very Low Frequency Earthquakes: An Evidence of Transition Zone between Brittle and Ductile Zone along Plate Boundary

NASA Astrophysics Data System (ADS)

Ishihara, Y.; Yamamoto, Y.; Arai, R.

2017-12-01

Recently slow or low frequency seismic and geodetic events are focused under recognition of important role in tectonic process. The most western region of Ryukyu trench, Yaeyama Islands, is very active area of these type events. It has semiannual-like slow slip (Heki et.al., 2008; Nishimura et.al.,2014) and very frequent shallow very low frequency earthquakes near trench zone (Ando et.al.,2012; Nakamura et.al.,2014). Arai et.al.(2016) identified clear reverse phase discontinuity along plate boundary by air-gun survey, suggesting existence of low velocity layer including fluid. The subducting fluid layer is considered to control slip characteristics. On the other hand, deep low frequency earthquake and tremor observed at south-western Honshu and Shikoku of Japan are not identified well due to lack of high-quality seismic network. A broadband seismic station(ISG/PS) of Pacific21 network is operating in last 20 years that locates on occurrence potential area of low frequency earthquake. We tried to review continuous broadband record, searching low frequency earthquakes. In pilot survey, we found three very low frequency seismic events which are dominant in less than 0.1Hz component and are not listed in earthquake catalogue. Source locates about 50km depth and at transition area between slow slip event and active area of general earthquake along plate boundary. To detect small and/or hidden very low frequency earthquake, we applied matched filter analysis to continuous three components waveform data using pre-reviewed seismogram as template signal. 12 events with high correlation are picked up in last 10 years. Most events have very similar waveform, which means characteristics of repeating deep very low frequency earthquake. The event history of very low frequency earthquake is not related with one of slow slip event in this region. In Yaeyama region, low frequency earthquake, general earthquake and slow slip event occur dividing in space and have apparent

The influence of changes in soil moisture in association with geomorphic change on the formation of a subalpine coniferous forest on Mt. Akita-Komagatake, northern Japan

NASA Astrophysics Data System (ADS)

Konno, A.

2015-12-01

The coniferous forest (largely composed of Abies mariesii) is presently the typical vegetation of the subalpine zone in Japan. Pollen analysis revealed that few A. mariesii were present during the last glacial period, and the species began to expand to the subalpine zone during the Holocene (Morita, 1992). However, on Mt. Akita-Komagatake in northern Japan, the expected predominance of A. mariesii is not extensively observed, and the predominant vegetation is instead the dwarf bamboo (Sasa kurilensis). It is unknown why the area under coniferous forest is small in this region. Therefore, I examined this issue from the perspectives of (1) distribution of vegetation, (2) geomorphology, (3) soil moisture, and (4) vegetation history. (1) Precise digital elevation model data and photographic interpretation showed that this coniferous forest was densely distributed in a flat segment considered to be formed by a landslide; (2) this landslide is thought to have occurred up to 3,699 ± 26 yr BP because a boring-core specimen from the landslide included the AK-3 tephra layer (2,300-2,800 yr BP: Wachi et al, 1997) and the radiocarbon date of the lowermost humic soil layer was 3,699 ± 26 yr BP; (3) the soil in the forest area had higher volumetric water content than that in the non-forest area; and (4) phytolith analysis revealed that the main species in the study site was initially dwarf bamboo, but coniferous forest replaced it after the Towada-a tephra (1035 cal. BP, Machida and Arai, 1992) layer fell. These results suggest that soil water conditions changed because of the formation of the flat segment by the landslide, and the coniferous forest was consequently established. However, the landslide only indirectly affected the formation of the coniferous forest, because the forest developed over several thousand years after the landslide occurred. In other words, more direct reasons for the establishment of the coniferous forest may involve changes in soil moisture. This

Do plumes exist beneath Northwest Kyushu southwest Japan?

NASA Astrophysics Data System (ADS)

Mashima, H.

2014-12-01

A thermal plume model was proposed for the Hot-spot type volcanism at Northwest Kyushu, southwest Japan in the post period of opening of the Sea of Japan. The model regards the Northwest Kyushu Basalts (NWKBs) were magmas fractionated from parental magmas with MgO = 12.8 - 18.8 wt. %, indicating that partial melting occurred at temperatures from 1330 to 1500 °C and at pressures from 1.5 to 3.0 GPa (Sakuyama et al., 2009; 2014). Previous petrological and observations, however, indicate that the NWKBs separated from the source mantle at pressures shallower than those inferred from the plume model. The Mg-Fe-Ni compositions of some NWKBs suggest that they could have been in equilibrium with mantle olivines with Fo = 81 - 87, meaning that they would have been not fractionated but primitive magmas. The NWKBs are associated with primitive high magnesium andesites, indicating that partial melting continued at low pressure such as 0.5 GPa (Mashima, 2009a, b). NWKBs include not garnet lherzolite xenoliths but spinel lherzolite, showing that primitive melt separation occurred at pressure lower than 2GPa (Arai et al., 2001). These lines of evidence indicate that the separation of primitive NWKBs occurred at temperature up to 1250　°C and pressures from 0.5 to 1.5 GPa, significantly lower than those assumed by the plume model. Instead of the plume model, geology of NW Kyushu infers that the volcanism was a consequence of the tectonic evolution of NW Kyushu. The volcanism was leaks of asthenosphere thickened extensional tectonics from the Paleogene to the early Miocene. Orientations of NWKB dikes indicate their eruption was induced by the reactivation of preexisting faults under horizontal compressive stress field oriented to a NW-SE direction. This　horizontally compressive stress field would have been caused by mechanical interactions between the subducting Philippine Sea pate and the Eurasian Plate. The NW Kyushu volcanism could be explained in the context of plate

Tabulation of comet observations.

NASA Astrophysics Data System (ADS)

1991-07-01

Concerning comets: 1957 III Arend-Roland, 1957 V Mrkos, 1958 III Burnham, 1959 III Bester-Hoffmeister, 1959 VI Alcock, 1959 VIII P/Giacobini-Zinner, 1960 I P/Wild 1, 1960 II Burnham, 1960 III P/Schaumasse, 1960 VIII P/Finlay, 1961 V Wilson-Hubbard, 1961 VIII Seki, 1962 III Seki-Lines, 1962 VIII Humason, 1963 I Ikeya, 1963 III Alcock, 1963 V Pereyra, 1964 VI Tomita-Gerber-Honda, 1964 VIII Ikeya, 1964 IX Everhart, 1979 X Bradfield, 1980 X P/Stephan-Oterma, 1980 XII Meier, 1980 XIII P/Tuttle, 1981 II Panther, 1982 I Bowell, 1982 IV P/Grigg-Skjellerup, 1982 VII P/d'Arrest, 1986 III P/Halley, 1987 IV Shoemaker, 1987 XII P/Hartley 3, 1987 XIX P/Schwassmann-Wachmann 2, 1987 XXIX Bradfield, 1987 XXX Levy, 1987 XXXII McNaught, 1987 XXXIII P/Borrelly, 1987 XXXVI P/Parker-Hartley, 1987 XXXVII P/Helin- Roman-Alu 1, 1988 III Shoemaker-Holt, 1988 V Liller, 1988 VIII P/Ge-Wang, 1988 XI P/Shoemaker-Holt 2, 1988 XIV P/Tempel 2, 1988 XV Machholz, 1988 XX Yanaka, 1988 XXI Shoemaker, 1988 XXIV Yanaka, 1989 III Shoemaker, 1989 V Shoemaker-Holt-Rodriquez, 1989 VIII P/Pons-Winnecke, 1989 X P/Brorsen-Metcalf, 1989 XI P/Gunn, 1989 XIII P/Lovas 1, 1989 XVIII McKenzie-Russell, 1989 XIX Okazaki-Levy-Rudenko, 1989 XX P/Clark, 1989 XXI Helin-Ronan-Alu, 1989 XXII Aarseth-Brewington, 1989h P/Van Biesbroeck, 1989t P/Wild 2, 1989u P/Kearns-Kwee, 1989c1 Austin, 1989e1 Skorichenko-George, 1990a P/Wild 4, 1990b Černis-Kiuchi-Nakamura, 1990c Levy, 1990e P/Wolf-Harrington, 1990f P/Honda-Mrkos-Pajdušáková, 1990g McNaught-Hughes, 1990i Tsuchiya-Kiuchi, 1990n P/Taylor, 1990ο P/Shoemaker-Levy 1, 1991a P/Metcalf-Brewington, 1991b Arai, 1991c P/Swift-Gehrels, 1991d Shoemaker-Levy, 1991e P/Shoemaker-Levy 3, 1991h P/Takamizawa, 1991j P/Hartley 1, 1991k P/Mrkos, 1991l Helin-Lawrence, 1991n P/Faye, 1991q P/Levy, 1991t P/Hartley 2, P/Encke, P/Schwassmann-Wachmann 1.

Subsurface structure around Omi basin using borehole database

NASA Astrophysics Data System (ADS)

Kitada, N.; Ito, H.; Takemura, K.; Mitamura, M.

2015-12-01

Kansai Geo-informatics Network (KG-NET) is organized as a new system of management of GI-base in 2005. This organization collects the geotechnical and geological information of borehole data more than 60,000 data. GI-base is the database system of the KG-NET and platform to use these borehole data. Kansai Geo-informatics Research Committee (KG-R) is tried to explain the geotechnical properties and geological environment using borehole database in Kansai area. In 2014, KG-R established the 'Shin-Kansai Jiban Omi plain', and explain the subsurface geology and characteristics of geotechnical properties. In this study we introduce this result and consider the sedimental environment and characteristics in this area. Omi Basin is located in the central part of Shiga Prefecture which includes the largest lake in Japan called Lake Biwa. About 15,000 borehole data are corrected to consider the subsurface properties. The outline of topographical and geological characteristics of the basin is divided into west side and east side. The west side area is typical reverse fault called Biwako-Seigan fault zone along the lakefront. From Biwako-Seigan fault, the Omi basin is tilting down from east to west. Otherwise, the east areas distribute lowland and hilly area comparatively. The sedimentary facies are also complicate and difficult to be generally evaluated. So the discussion has been focused about mainly the eastern and western part of Lake Biwa. The widely dispersed volcanic ash named Aira-Tn (AT) deposited before 26,000-29,000 years ago (Machida and Arai, 2003), is sometimes interbedded the humic layers in the low level ground area. However, because most of the sediments are comprised by thick sand and gravels whose deposit age could not be investigated, it is difficult to widely identify the boundary of strata. Three types of basement rocks are distributed mainly (granite, sediment rock, rhyolite), and characteristics of deposit are difference of each backland basement rock

A mutation of RNA polymerase β' subunit (RpoC) converts heterogeneously vancomycin-intermediate Staphylococcus aureus (hVISA) into "slow VISA".

PubMed

Matsuo, Miki; Hishinuma, Tomomi; Katayama, Yuki; Hiramatsu, Keiichi

2015-07-01

Various mutations in the rpoB gene, which encodes the RNA polymerase β subunit, are associated with increased vancomycin (VAN) resistance in vancomycin-intermediate Staphylococcus aureus (VISA) and heterogeneously VISA (hVISA) strains. We reported that rpoB mutations are also linked to the expression of the recently found "slow VISA" (sVISA) phenotype (M. Saito, Y. Katayama, T. Hishinuma, A. Iwamoto, Y. Aiba, K Kuwahara-Arai, L. Cui, M. Matsuo, N. Aritaka, and K. Hiramatsu, Antimicrob Agents Chemother 58:5024-5035, 2014, http://dx.doi.org/10.1128/AAC.02470-13). Because RpoC and RpoB are components of RNA polymerase, we examined the effect of the rpoC(P440L) mutation on the expression of the sVISA phenotype in the Mu3fdh2*V6-5 strain (V6-5), which was derived from a previously reported hVISA strain with the VISA phenotype. V6-5 had an extremely prolonged doubling time (DT) (72 min) and high vancomycin MIC (16 mg/liter). However, the phenotype of V6-5 was unstable, and the strain frequently reverted to hVISA with concomitant loss of low growth rate, cell wall thickness, and reduced autolysis. Whole-genome sequencing of phenotypic revertant strain V6-5-L1 and comparison with V6-5 revealed a second mutation, F562L, in rpoC. Introduction of the wild-type (WT) rpoC gene using a multicopy plasmid resolved the sVISA phenotype of V6-5, indicating that the rpoC(P440L) mutant expressed the sVISA phenotype in hVISA. To investigate the mechanisms of resistance in the sVISA strain, we independently isolated an additional 10 revertants to hVISA and VISA. In subsequent whole-genome analysis, we identified compensatory mutations in the genes of three distinct functional categories: the rpoC gene itself as regulatory mutations, peptidoglycan biosynthesis genes, and relQ, which is involved in the stringent response. It appears that the rpoC(P440L) mutation causes the sVISA phenotype by augmenting cell wall peptidoglycan synthesis and through the control of the stringent response

A whole rock absolute paleointensity determination of dacites from the Duffer Formation (ca. 3.467 Ga) of the Pilbara Craton, Australia: An impossible task?

NASA Astrophysics Data System (ADS)

Herrero-Bervera, Emilio; Krasa, David; Van Kranendonk, Martin J.

2016-09-01

We have conducted a whole-rock type magnetic and absolute paleointensity determination of the red dacite of the Duffer Formation from the Pilbara Craton, Australia. The age of the dated rock unit is 3467 ± 5 Ma (95% confidence). Vector analyses results of the step-wise alternating field demagnetization (NRM up to 100 mT) and thermal demagnetization (from NRM up to 650 °C) yield three components of magnetization. Curie point determinations indicate three characteristic temperatures, one at 150-200 °C, a second one at ∼450 °C and a third one at ∼580 °C. Magnetic grain-size experiments were performed on small specimens with a variable field translation balance (VFTB). The coercivity of remanence (Hcr) suggests that the NRM is carried by low-coercivity grains that are associated with a magnetite fraction as is shown by the high-temperature component with blocking temperatures above 450 °C and up to at least 580 °C. The ratios of the hysteresis parameters plotted as a modified Day diagram show that most grain sizes are scattered within the Single Domain (SD) and the Superparamagnetic and Single Domain SP-SD domain ranges. In addition to the rock magnetic experiments we have performed absolute paleointensity experiments on the samples using the modified Thellier-Coe double heating method to determine the paleointensities. Partial-TRM (p-TRM) checks were performed systematically to document magnetomineralogical changes during heating. The temperature was incremented by steps of 50 °C between room temperature and 590 °C. The paleointensity determinations were obtained from the slope of Arai diagrams. Our paleointensity results indicate that the paleofield obtained was ∼6.4 ± 0.68 (N = 11) micro-Teslas with a Virtual Dipole Moment (VDM) of 1.51 ± 0.81 × 1022 Am2, from a medium-to high-temperature component ranging from 300 to 590 °C that has been interpreted to be the oldest magnetization yet recorded in paleomagnetic studies of the Duffer Formation. The

The Kinetic Behavior of Benzaldehyde under Hydrothermal Conditions

NASA Astrophysics Data System (ADS)

Fecteau, K.; Gould, I.; Hartnett, H. E.; Williams, L. B.; Shock, E.

2013-12-01

, metamorphism, and other hydrothermal processes of interest occur in natural systems. References Ikushima, Y., K. Hatakeda, O. Sato, T. Yokoyama, and M. Arai. 2001. Structure and base catalysis of supercritical water in the noncatalytic benzaldehyde disproportionation using water at high temperatures and pressures. Angewandte Chemie, 40, 210-213. Tsao, C.C., Y. Zhou, X. Liu, and T.J. Houser. 1992. Reactions of supercritical water with benzaldehyde, benzylidenebenzylamine, benzyl alcohol, and benzoic acid. The Journal of Supercritical Fluids, 5, 107-113.

Mantle water contents beneath the Rio Grande Rift (NM, USA): FTIR analysis of Rio Puerco and Kilbourne Hole peridotite xenoliths

NASA Astrophysics Data System (ADS)

Schaffer, L. A.; Peslier, A. H.; Brandon, A. D.; Selverstone, J.

2015-12-01

Peridotite xenoliths from the Rio Grande Rift (RGR) are being analyzed for H2O contents by FTIR as well as for major and trace element compositions. Nine samples are from the Rio Puerco Volcanic Field (RP) which overlaps the central RGR and southeastern Colorado Plateau; seventeen samples are from Kilbourne Hole (KH) in the southern RGR. Spinel Cr# (Cr/(Cr+Al) = 0.08-0.46) and olivine Mg# (Mg/(Mg+Fe) = 0.883-0.911) of samples fall within the olivine-spinel mantle array from [1], an indicator that these are residues of partial melting. Pyroxene H2O contents in KH correlate with bulk rock and pyroxene Al2O3 contents. The KH clinopyroxene rare earth element (REE) variations fit models of 0-13% fractional melting of a primitive upper mantle. Most KH peridotites have bulk-rock light REE depleted patterns, but five are enriched in light REEs consistent with metasomatism. Variation in H2O content seems unrelated to REE enrichment. Metasomatism is seen in RP pyroxenite xenoliths [2] and will be examined in the peridotites studied here. Olivine H2O contents are low (≤20 ppm), and decrease from core to rim within grains. This is likely due to H loss during xenolith transport by the host magma [3]. Diffusion models of H suggest that mantle H2O contents are still preserved in cores of KH olivine, but not those of RP olivine. The average H2O content of Colorado Plateau clinopyroxene (670 ppm) [4] is ~300 ppm higher than RGR clinopyroxene (350 ppm). This upholds the hypothesis that hydration-induced lithospheric melting occurred during flat-slab subduction of the Farallon plate [5]. Numerical models indicate hydration via slab fluids is possible beneath the plateau, ~600 km from the paleo-trench, but less likely ~850 km away beneath the rift [6]. [1]Arai, 1994 CG 113, 191-204.[2]Porreca et al., 2006 Geosp 2, 333-351.[3]Peslier and Luhr, 2006 EPSL 242, 302-319.[4]Li et al., 2008 JGR 113, 1978-2012.[5]Humphreys et al., 2003 Int Geol Rev 45, 575-595.[6]English et al., 2003 EPSL

EDITORIAL: MST Best Paper Award for 2004

NASA Astrophysics Data System (ADS)

Gill, Patrick

2005-12-01

For the last 13 years, Measurement Science and Technology has awarded a Best Paper prize. The Editorial Board of the journal believes that such a prize is an opportunity to thank authors for submitting their work, and serves as an integral part of the on-going quality review of the journal. An Editorial Board working party, comprising Patrick Gill (Chairman), David Birch and Ralph Tatam undertook the task of selecting as Best Paper 2004 a single contributed paper describing new and significant work, well aligned with the measurement scope of the journal, and presented in clear and rigorous form. They received a number of recommendations from the Editorial and International Advisory Board Members, and they would like to record their thanks to the Members for these recommendations, as they form an all-important first stage in the assessment process. There were responses from some five Board Members. In total, there were 16 papers nominated, plus another six from the working party. All these papers had quality ratings of 2 or higher from the referees, and note was also taken of the total electronic accesses for those papers subsequently short-listed. Review Articles, and papers that included a Board Member as an author, were automatically excluded. From the submitted nominations and working party deliberations, a short list of two papers was drawn up. The winning paper was then selected on the totality of criteria. Thus the paper recommended by the working party for the MST Best Paper Award for 2004 is: 'Adsorptive pressure-sensitive coatings on porous anodised aluminium' by Masaharu Kameda, Norikazu Tezuka, Tomohiro Hangai, Keisuke Asai, Kazuyuki Nakakita and Yutaka Amao, 15 489-500 (2004) This paper describes a novel pressure sensor based on a luminescent coating applied to a porous anodized aluminium layer, with application to the measurement of fluctuating pressures on short timescales with high spatial resolution. The research has particular application to

Uranium in surface soils: an easy-and-quick assay combining X-ray diffraction and fluorescence qualitative data

NASA Astrophysics Data System (ADS)

Figueiredo, M. O.; Silva, T. P.; Batista, M. J.; Leote, J.; Ferreira, M. L.; Limpo, V.

2009-04-01

discovery and valorisation (in Portuguese). Internal Rept., JEN, 20 pp. [3] http://www.naturtejo.com [4] J.A. Davis et al. (2006) Processes affecting transport of uranium in a suboxic aquifer. Phys. Chem. of the Earth 31, 548-555. [5] Y. Arai et al. (2007) Spectroscopic evidence for uranium bearing precipitates in Vadose zone sediments at the Hanford 300-Area site. Environ. Sci. Technol. 41, 4633-4639. [6] A. Kremleva, S. Krüger & N. Rösch (2008) Density functional model studies of uranyl adsorption on (001) surfaces of kaolinite. Langmuir 24, 9515-9524.

Palaeogeographic evolution of the central segment of the South Atlantic during Early Cretaceous times: palaeotopographic and geodynamic implications

NASA Astrophysics Data System (ADS)

Chaboureau, A. C.; Guillocheau, F.; Robin, C.; Rohais, S.; Moulin, M.; Aslanian, D.

2012-04-01

influences were clearly occurring since the Early Aptian in the Northern domain and the Campos Basin. They seem sharp, brief flooding coming from the North, i.e. from the Tethys-Central Atlantic, trough a seaway crossing South America from Sao Luis, Parnaiba, Araripe and Almada basins (Arai, 1989). In the absence of data, the importance of those marine flooding during the Middle Aptian in the Santos Basin is still discussed. Keywords: South Atlantic Ocean, Early Cretaceous, Rift, Palaeogeography, Geodynamic

Tabulation of comet observations.

NASA Astrophysics Data System (ADS)

1993-10-01

Concerning comets: 1955 III Mrkos, 1955 IV Bakharev-Macfarlane-Krienke, 1955 V Honda, 1956 III Mrkos, 1956 IV P/Olbers, 1957 III Arend-Roland, 1957 V Mrkos, 1958 III Burnham, 1959 VIII P/Giacobini-Zinner, 1960 II Burnham, 1973 XII Kohoutek, 1974 III Bradfield, 1975 IX Kobayashi-Berger-Milon, 1975 X Suzuki-Saigusa-Mori, 1975 XI Bradfield, 1975 XII Mori-Sato-Fujikawa, 1976 IV Bradfield, 1976 VI West, 1979 VII Bradfield, 1980 X P/Stephan-Oerma, 1980 XII Meier, 1980 XIII P/Tuttle, 1981 II Panther, 1981 IV P/Borrelly, 1981 XIX P/Swift-Gehrels, 1982 I Bowell, 1982 IV P/Grigg-Skjellerup, 1982 VI Austin, 1982 VII P/d'Arrest, 1982 VIII P/Churyumov-Gerasimenko, 1983 V Sugano-Saigusa-Fujikawa, 1983 VII IRAS-Araki-Alcock, 1983 X P/Tempel 2, 1983 XI P/Tempel 1, 1983 XIII P/Kopff, 1983 XIV P/IRAS, 1983 XV Shoemaker, 1984 III P/Hartley-IRAS, 1984 IV P/Crommelin, 1984 XI P/Faye, 1984 XIII Austin, 1984 XIV P/Wild 2, 1984 XVI P/Shoemaker 1, 1984 XXIII Levy-Rudenko, 1985 I P/Tsuchinshan 1, 1985 XIII P/Giacobini-Zinner, 1985 XV P/Giclas, 1985 XVI P/Ciffréo, 1985 XVII Hartley-Good, 1985 XVIII P/Shoemaker 3, 1985 XIX Thiele, 1986 I P/Boethin, 1986 III P/Halley, 1986 VIII P/Machholz, 1986 XVII Levy, 1986 XVIII Terasako, 1987 II Sorrells, 1987 VII Wilson, 1987 XIX P/Schwassmann-Wachmann 2, 1987 XXI Levy, 1987 XXIII Rudenko, 1987 XXIV P/Brooks 2, 1987 XXVII P/Kohoutek, 1987 XXIX Bradfield, 1988 IV Furuyama, 1988 XIV P/Tempel 2, 1989 III Shoemaker, 1989 XV P/Schwassmann-Wachmann 1, 1989 XIX Okazaki-Levy-Rudenko, 1990 V Austin, 1990 XVII Tsuchiya-Kiuchi, 1990 XX Levy, 1990 XXI P/Encke, 1990 XXVI Arai, 1991 I P/Metcalf-Brewington, 1991 XV P/Hartley 2, 1991 XVII P/Arend-Rigaux, 1991a1 Shoemaker-Levy, 1991g1 Zanotta-Brewington, 1992c P/Howell, 1992d Tanaka-Machholz, 1992e P/Singer Brewster, 1992f P/Shoemaker-Levy 8, 1992h Spacewatch, 1992j P/Ashbrook-Jackson, 1992t P/Swift-Tuttle, 1992u P/Väisälä 1, 1992w P/Slaughter-Burnham, 1992x P/Schaumasse, 1992y Shoemaker, 1993a Mueller, 1993d Mueller

Selective Absorption Mechanism for the Maintenance of Blocking

NASA Astrophysics Data System (ADS)

Yamazaki, Akira; Itoh, Hisanori

2010-05-01

Atmospheric blocking is one of the most influential phenomena in global atmospheric environments. The understanding of its dynamical processes is important to clarify weather extremes and the stratosphere-troposphere coupling and to extend forecast periods. In the dynamics of blocking, especially, its maintenance mechanism has been a stimulating topic for many meteorologists. About the maintenance mechanism of blocking, Shutts (1983) evaluated the effect of synoptic eddies in his numerical model and proposed the Eddy Straining Mechanism (hereafter, referred to as ESM). Using simple numerical models, he demonstrated that synoptic eddies strained in the north-south direction by blocking provide negative/positive vorticity to a blocking high/low and this vorticity forcing, i.e., the second-order flow maintains the blocking dipole structure against dissipation. Some pieces of evidence, however have shown that the ESM does not work well in several real cases of the block maintenance. For example, Arai and Mukougawa (2002) performed a similar experiment to Shutts (1983) and indicated the strong sensitivity of the ESM against a small meridional shift of the stormtrack (strictly speaking, wavemaker), or a small change of the size of high-frequency eddies. This is a very adverse constraint in the real atmosphere because the relative positions of blocking to the stormtrack tend to fluctuate from case to case so that they do not necessarily exist in the same latitude band. Thus, we propose a more realistic mechanism of the block maintenance named as the Selective Absorption Mechanism (hereafter referred to as SAM), in which a blocking anticyclone selectively and exclusively absorbs synoptic anticyclones. This mechanism is essentially the same mechanism as the Fujiwhara effect, which qualitatively explains that binary eddies with the same polarity merge and eddies with the opposite polarity separate. In this study, we verify the effectiveness of the SAM by observational

First report on Cretaceous paleoweathering rates in western Panthalassa: Evidence of global enhancement of continental weathering during OAE 2

NASA Astrophysics Data System (ADS)

Ohta, T.

2013-12-01

Mid-Cretaceous is characterized by intensified oceanic anoxia (Oceanic Anoxic Events: OAEs) that raised global deposition of organic black shales. Several models have been proposed to explain the cause of the OAEs in conjunction with Cretaceous global warmth, active volcanism, sea-level changes and others. For example, Weissert et al. (1998) proposed a mechanism called 'weathering hypothesis'. In this model, the cause of the OAEs is explained in a following chain reaction, (1) global warmth and increase in atmospheric CO2 enhanced weathering of continental crust, (2) enhanced land weathering led excessive influx of nutrients from continents to oceans, (3) eutrophication enhanced primary productivity, (4) the excessive primary producers consumed dissolved oceanic oxygen that finally led to the OAEs. Several studies, in fact, revealed a causal relation between enhanced weathering and OAEs in northern Tethys region. However, it is necessary to collect worldwide information to unravel the global response of weathering hypothesis as a cause of OAEs. For such reason, the present contribution conducted measurements of the degree of hinterland paleoweathering during OAEs in northern Japan, for the purpose to provide a first report on the relation between continental weathering and OAEs in open ocean, the western Panthalassa Ocean. Aptian to Campanian forearc basin mudstones (Yezo Group) were analyzed by XRF and the degree of hinterland weathering was evaluated by geochemical weathering index (W index; Ohta and Arai, 2007). The W values obtained for the Yezo Group are 30~50, which is equivalent to the W values of recent soils developed in temperate mid-latitude climate. The W values show a fluctuation pattern that is concordant with the Cretaceous paleotemperature changes. This match indicates that the change in paleotemperature governed the weathering rates of East Asian continental crust. In addition, hinterland weathering rates show instantaneous increase during the OAE

Cognitive and Behavioral Skills Exercises Completed by Patients with Major Depression During Smartphone Cognitive Behavioral Therapy: Secondary Analysis of a Randomized Controlled Trial.

PubMed

Furukawa, Toshi A; Horikoshi, Masaru; Fujita, Hirokazu; Tsujino, Naohisa; Jinnin, Ran; Kako, Yuki; Ogawa, Sei; Sato, Hirotoshi; Kitagawa, Nobuki; Shinagawa, Yoshihiro; Ikeda, Yoshio; Imai, Hissei; Tajika, Aran; Ogawa, Yusuke; Akechi, Tatsuo; Yamada, Mitsuhiko; Shimodera, Shinji; Watanabe, Norio; Inagaki, Masatoshi; Hasegawa, Akio

2018-01-11

tasks, engaged in different types of activities, and also filled in more cognitive restructuring worksheets than the latter. Activities such as "test-drive a new car," "go to a coffee shop after lunch," or "call up an old friend" were found to be particularly rewarding. All cognitive restructuring strategies were found to significantly decrease the distress level, with "What would be your advice to a friend who has a similar problem?" found more helpful than some other strategies. The CBT program offered via smartphone and connected to the remote server is not only effective in alleviating depression but also opens a new avenue in gathering information of what and how each participant may utilize the program. The activities and strategies found useful in this analysis will provide valuable information in brush-ups of the program itself and of mobile health (mHealth) in general. Japanese Clinical Trials Registry UMIN CTR 000013693; https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ ctr_view.cgi?recptno=R000015984 (Archived by WebCite at http://www.webcitation.org/6u6pxVwik). ©Toshi A Furukawa, Masaru Horikoshi, Hirokazu Fujita, Naohisa Tsujino, Ran Jinnin, Yuki Kako, Sei Ogawa, Hirotoshi Sato, Nobuki Kitagawa, Yoshihiro Shinagawa, Yoshio Ikeda, Hissei Imai, Aran Tajika, Yusuke Ogawa, Tatsuo Akechi, Mitsuhiko Yamada, Shinji Shimodera, Norio Watanabe, Masatoshi Inagaki, Akio Hasegawa. Originally published in JMIR Mental Health (http://mental.jmir.org), 11.01.2018.

The peculiar case of Marosticano xenoliths: a cratonic mantle fragment affected by carbonatite metasomatism in the Veneto Volcanic Province (Northern Italy)

NASA Astrophysics Data System (ADS)

Brombin, Valentina; Bonadiman, Costanza; Coltorti, Massimo; Florencia Fahnestock, M.; Bryce, Julia G.; Marzoli, Andrea

2017-04-01

high chromium contents (cr#=(Cr/(Cr+Al)X100); lh: 30-53; hz: 38-67) in coexisting spinel, out of the typical OSMA array (Arai, 1994b) is observed in typical on-craton mantle rocks (Downes et al., 2004). To corroborate the cratonic "flavour" of these peridotites, in-situ trace element analyses show that Marosticano clinopyroxene have modified their residual characteristics by interaction with deep metasomatic melt, which was able to strong enrich in U, Th, LILE (Rb-Ba) and LREE with respect to the restitic preserved HREE and HFSE (e.g. Nb, Ta, Zr and Hf) contents. The general clinopyroxene trace element distribution and elemental ratios ((La/Yb)N and Ti/Eu; Coltorti et al., 1999) are consistent with enrichment provided by a carbonatitic rather than a silicate metasomatizing agent. To characterize the chemical-physical frame of the MA mantle segment, peridotites equilibration temperatures and oxygen fugacities were also estimated and compared with those of the other VVP xenoliths. The latter comparison leads to i) Marosticano samples record relatively high oxidation conditions (as Mts. Lessini peridotites) in agreement with the range assigned to continental lithosphere (Foley et al., 2011) and ii) these T-fO2 values account for CO2 mole fractions dissolved in a potential metasomatic melt close to 1, further supporting the carbonatitic nature of the infiltrating melt. In this case it can be speculated that the usually low oxidizing conditions of the cratonic mantle have been augmented by the interaction with a carbonatitic melt or with a CO2-rich fluid released by the reaction with a peridotitic matrix. References Arai, S., 1994b. Compositional variation of olivine chromian spinel in Mg-rich magmas as a guide to their residual spinel peridotites. Journal of Volcanology and Geothermal Research 59, 279-293. Beccaluva L., Bianchini G., Bonadiman C., Coltorti M., Milani L., Salvini L., Siena F., Tassinari R. (2007). Intraplate lithospheric and sublithospheric components in

Mechanisms of formation of mantle section pyroxenites of Voykar Ophiolite, Polar Urals, Russia

NASA Astrophysics Data System (ADS)

Belousov, Ivan; Batanova, Valentina; Sobolev, Alexander; Savelieva, Galina

2010-05-01

Ural Mountains mark a major mid Paleozoic collision event, which resulted in the closure of an ocean basin separating the Siberian and European plates. Voykar Ophiolite is located in the Northern part of Uralian Ophiolite Belt. Ophiolitic sequence rocks of Polar Urals are usually considered as giant fragments of mantle and MORB-type crust formed in back-arc settings (e.g. Savelieva et al., 1987). Mantle section of Voykar Ophiolite comprises most of the ophiolitic sequence. It is up to 8 km thick and consists mostly of spinel harzburgites with multiple dunitic bodies and pyroxenitic veins representing pathways for different melts/fluids. While it is generally accepted that dunites in mantle sections are formed by melt-rock reaction and mark melt pathways (e.g. Kelemen et al., 1995), formation of pyroxenites is a subject of debate. Often pyroxenites from mantle sections of ophiolites (Varfalvy et al., 1997), as well as pyroxenites from mantle wedge xenoliths (Arai et al., 2006, Bali et al., 2007, Gregoire et al., 2008) are interpreted as interaction products between high-SiO2 melts and mantle peridotites. Such melts are believed to be widespread in SSZ mantle: boninites, high-MgO andesites and adakites. However, some researchers (e.g. Berly et al., 2006, Halama et al., 2009) propose pyroxenite formation in metasomatic reaction with fluid from subducting plate. Moreover, some pyroxenites could be formed by the melt crystallization in hydrous conditions (Muntener et al., 2001). We present comprehensive study of mineral major and trace element compositions from the mantle section rocks of Voykar Ophiolite in order to determine mechanism of formation of pyroxenites in ophiolitic mantle sections. Compositions of clinopyroxene and olivine from pyroxenites were compared to their compositions in harzburgites and dunites. Furthermore, compositions of clinopyroxene and magmatic amphibole from mantle section pyroxenites were used to calculate equilibrium melts. Geochemical data

Geochemistry of sapphirine-apatite-calcite-bearing gabbroic dykes from the Finero Phlogopite Peridotite (Ivrea-Verbano Zone): evidence for multistage interaction with the ambient peridotite

NASA Astrophysics Data System (ADS)

Tommaso, Giovanardi; Alberto, Zanetti; Maurizio, Mazzucchelli; Tomoaki, Morishita; Antonio, Langone

2016-04-01

sapphirine (Giovanardi et al., 2013). The mineral assemblage of the veins is dominated by titanian pargasite towards the host peridotite and by plagioclase at the vein centre. The veins also present phlogopite and spinel. Field and petrographic evidence, major and trace element data and the O isotopic composition of such gabbroic veins indicate that they formed at shallow mantle conditions by multistage fractional crystallisation of a migrating melt unrelated to those forming phlogopite harzburgites. Besides, local strong enrichments in LILE, LREE and 18O in vein minerals confirm that such melt was deeply modified by interaction with the host phlogopite peridotite. The genetic relationships with other intrusive events recorded by the FPP and the associated crustal sequence will be addressed with the aim of placing new constraints on the petrologic and geodynamic evolution of the IVZ. Giovanardi, T., Morishita, T., Zanetti, A., Mazzucchelli, M., Vannucci, R. (2013). Igneous sapphirine as a product of melt-peridotite interactions in the Finero Phlogopite-Peridotite Massif, Western Italian Alps. European Journal of Mineralogy 25, 17-31. Morishita, T., Hattori, K.H., Terada, K., Matsumoto, T., Yamamoto, K., Takebe, M., Ishida, Y., Tamura, A., Arai, S. (2008). Geochemistry of apatite-rich layers in the Finero phlogopite-peridotite massif (Italian Western Alps) and ion microprobe dating of apatite. Chemical Geology 251, 99-111. Zanetti, A., Mazzucchelli, M., Rivalenti, G., Vannucci, R. (1999). The Finero phlogopite-peridotite massif: an example of subduction-related metasomatism. Contributions to Mineralogy and Petrology 134, 107-122.

Distribution and PGE mineralization in the formation of chromitite in ophiolite complexes (Ospina-Kitoi Kharanur and ultrabasic massifs of Eastern Sayan, Sousern Siberia)

NASA Astrophysics Data System (ADS)

Kiseleva, Olga; Zhmodik, Sergei

2015-04-01

New study of PGE in restitic ultrabasic (Kharanur and Ospin-Kitoi) massifs from North and South branches (Dobretsov et al., 1985) of the ophiolite complexes in south-eastern part of the Eastern Sayan show their presence in chromitites of both branches belonging to the different geodynamic settings. Modern concepts model includes several mechanisms of podiform chromitite origin reflected in the chemistry of Cr-spinels (Arai, Yurimoto, 1994; Ballhaus, 1998; Uysal et al., 2009 et al.): 1) partial melting of upper mantle rocks, 2) mixing of primitive melts with melts enriched in SiO2, 3) melt-rock interaction. We estimated the types of interaction of mafic melts with mantle peridotites, with the formation of chromite bodies. For ore chrome spinelides from northern branch (Al2O3) melt = 8 - 14 wt%, (TiO2) melt = 0 - 0,4 wt%, (Fe/Mg) melt = 0,5 - 2,4; Southern branch (Al2O3) melt = 10 - 13 wt%, (TiO2) melt = 0,1 wt%, (Fe/Mg) melt = 0,3 - 1 (Kiseleva, 2014). There are two types of PGE distribution Os-Ir-Ru (I) and Pt-Pd (II). Type I chromitites (mid-Al#Cr-spinels) revealed only Os-Ir-Ru distributions; type II (low-Al#Cr spinelides) show both Os-Ir-Ru and (Pt-Pd) distributions (Kiseleva et al., 2012, 2014). PGE distribution in ultramafic peridotites and chromitites reflects PGE fractionation during partial melting (Barnes et al., 1985; Rehkämper et al., 1997). Processes bringing to extreme fractionation of PGE, may be associated with fluid-saturated supra subduction environment where melting degree near 20% and above is sufficient for the release of PGE from the mantle source (Dick, Bullen, 1984; Naldrett, 2010). Enrichment in PPGE together with a high content of IPGE in same chromite bodies is attributed to the second step of melting, and formation of S-enriched and saturated in PGE melts (Hamlyn, Keays, 1986; Prichard et al., 1996). For type I chromitites platinum group minerals (PGM) are presented by Os-Ir-Ru system. In type II chromitites PGM are represented by Os

Tabulation of comet observations.

NASA Astrophysics Data System (ADS)

1995-07-01

Concerning comets: C/1958 D1 (Burnham), C/1959 Q1 (Alcock), C/1959 Q2 (Alcock), C/1959 Y1 (Burnham), C/1960 Y1 (Candy), C/1961 O1 (Wilson-Hubbard), C/1961 R1 (Humason), C/1961 T1 (Seki), C/1962 H1 (Honda), C/1963 A1 (Ikeya), C/1963 F1 (Alcock), C/1963 R1 (Pereyra), C/1964 N1 (Ikeya), C/1964 P1 (Everhart), C/1966 P1 (Kilston), C/1966 P2 (Barbon), C/1966 R1 (Ikeya-Everhart), C/1966 T1 (Rudnicki), C/1967 Y1 (Ikeya-Seki), C/1968 H1 (Tago-Honda-Yamamoto), C/1968 L1 (Whitaker-Thomas), C/1968 N1 (Honda), C/1968 Q1 (Bally-Clayton), C/1968 Q2 (Honda), C/1968 U1 (Wild), C/1968 Y1 (Thomas), C/1969 O1 (Kohoutek), C/1969 P1 (Fujikawa), C/1969 Y1 (Bennett), C/1970 B1 (Daido-Fujikawa), C/1970 N1 (Abe), C/1970 U1 (Suzuki-Sato-Seki), C/1971 E1 (Toba), C/1972 E1 (Bradfield), C/1972 L1 (Sandage), C/1972 U1 (Kojima), C/1973 A1 (Heck-Sause), C/1973 E1 (Kohoutek), C/1975 T1 (Mori-Sato-Fujikawa), C/1975 T2 (Suzuki-Saigusa-Mori), C/1975 V1 (West), C/1975 V2 (Bradfield), C/1975 X1 (Sato), C/1976 D1 (Bradfield), C/1977 V1 (Tsuchinshan), C/1984 N1 (Austin), C/1987 P1 (Bradfield), C/1988 A1 (Liller), C/1989 Q1 (Okazaki-Levy-Rudenko), C/1989 X1 (Austin), C/1990 E1 (Černis-Kiuchi-Nakamura), C/1990 K1 (Levy), C/1990 N1 (Tsuchiya-Kiuchi), C/1991 A2 (Arai), C/1991 F2 (Helin-Lawrence), C/1991 T2 (Shoemaker-Levy), C/1991 X2 (Mueller), C/1991 Y1 (Zanotta-Brewington), C/1992 F1 (Tanaka-Machholz), C/1992 U1 (Shoemaker), C/1992 W1 (Ohshita), C/1994 J2 (Takamizawa), C/1994 N1 (Nakamura-Nishimura-Machholz), C/1994 T1 (Machholz), 1P/Halley, 2P/Encke, 4P/Faye, 6P/d'Arrest, 8P/Tuttle, 9P/Tempel 1, 10P/Tempel 2, 15P/Finlay, 16P/Brooks 2, 19P/Borrelly, 23P/Brorsen-Metcalf, 24P/Schaumasse, 29P/Schwassmann-Wachmann 1, 31P/Schwassmann-Wachmann 2, 40P/Väisälä 1, 41P/Tuttle-Giacobini-Kresák, 45P/Honda-Mrkos-Pajdušáková, 51P/Harrington, 59P/Kearns-Kwee, 64P/Swift-Gehrels, 65P/Gunn, 71P/Clark, 73P/Schwassmann-Wachmann 3, 75P/Kohoutek, 76P/West-Kohoutek-Ikemura, 77P/Longmore, 78P/Gehrels 2, 85P/Boethin, 95P

Collision and subduction structure of the Izu-Bonin arc, central Japan: Recent studies from refraction/wide-angle reflection analysis and seismic tomography

NASA Astrophysics Data System (ADS)

Arai, R.; Iwasaki, T.; Sato, H.; Abe, S.; Hirata, N.

2009-12-01

Since the middle Miocene, the Izu-Bonin arc has been colliding from south with the Honshu arc in central Japan associated with subduction of the Philippine Sea plate. This process is responsible for forming a complex crustal structure called the Izu collision zone. Geological studies indicate the several geological blocks derived from the Izu-Bonin arc, such as the Misaka Mountains (MM), the Tanzawa Mountains (TM) and the Izu Peninsula (IP), were accreted onto the Honshu crust in the course of the collision, forming several tectonic boundaries in and around this collision zone (e.g. Amano, 1991). Recent seismic experiments succeeded in revealing the deep crustal structure in the eastern part of the Izu collision zone by reflection analysis (Sato et al., 2005) and refraction/wide-angle reflection analysis (Arai et al., 2009). Although these studies delineate the collision boundary between the Honshu crust and TM, and the upper surface of the subducting Philippine Sea plate, the southern part of the profile including the Kozu-Matsuda Fault (KMF, the tectonic boundary between TM and IP) is not well constrained due to the poor ray coverage. Moreover, clear images of tectonic boundaries are not obtained for the central or western part of the collision zone. In order to construct the structure model dominated by collision and subduction for the whole part of the collision zone, we carried out the following two analyses: (1) refraction tomography of active source data including another profile line in the western part of the collision zone (Sato et al., 2006), and (2) seismic tomography combining active and passive source data. In the analysis (1), we applied first arrival seismic tomography (Zelt and Barton, 1998) to the refraction data .We inverted over 39,000 travel times to construct a P wave velocity model for the 75-km-long transect, and a fine-scale structure with strong lateral heterogeneity was recovered. We conducted checkerboard resolution test to evaluate a

Quantum Bio-Informatics IV

NASA Astrophysics Data System (ADS)

Accardi, Luigi; Freudenberg, Wolfgang; Ohya, Masanori

2011-01-01

The QP-DYN algorithms / L. Accardi, M. Regoli and M. Ohya -- Study of transcriptional regulatory network based on Cis module database / S. Akasaka ... [et al.] -- On Lie group-Lie algebra correspondences of unitary groups in finite von Neumann algebras / H. Ando, I. Ojima and Y. Matsuzawa -- On a general form of time operators of a Hamiltonian with purely discrete spectrum / A. Arai -- Quantum uncertainty and decision-making in game theory / M. Asano ... [et al.] -- New types of quantum entropies and additive information capacities / V. P. Belavkin -- Non-Markovian dynamics of quantum systems / D. Chruscinski and A. Kossakowski -- Self-collapses of quantum systems and brain activities / K.-H. Fichtner ... [et al.] -- Statistical analysis of random number generators / L. Accardi and M. Gabler -- Entangled effects of two consecutive pairs in residues and its use in alignment / T. Ham, K. Sato and M. Ohya -- The passage from digital to analogue in white noise analysis and applications / T. Hida -- Remarks on the degree of entanglement / D. Chruscinski ... [et al.] -- A completely discrete particle model derived from a stochastic partial differential equation by point systems / K.-H. Fichtner, K. Inoue and M. Ohya -- On quantum algorithm for exptime problem / S. Iriyama and M. Ohya -- On sufficient algebraic conditions for identification of quantum states / A. Jamiolkowski -- Concurrence and its estimations by entanglement witnesses / J. Jurkowski -- Classical wave model of quantum-like processing in brain / A. Khrennikov -- Entanglement mapping vs. quantum conditional probability operator / D. Chruscinski ... [et al.] -- Constructing multipartite entanglement witnesses / M. Michalski -- On Kadison-Schwarz property of quantum quadratic operators on M[symbol](C) / F. Mukhamedov and A. Abduganiev -- On phase transitions in quantum Markov chains on Cayley Tree / L. Accardi, F. Mukhamedov and M. Saburov -- Space(-time) emergence as symmetry breaking effect / I. Ojima

Textural evolution of a dunitic matrix during formation of hybrid troctolites: insights from the Monte Maggiore peridotitic body (Corsica, France).

NASA Astrophysics Data System (ADS)

Basch, Valentin; Rampone, Elisabetta; Crispini, Laura; Ildefonse, Benoit; Godard, Marguerite

2017-04-01

decrease of modal olivine coupled to increase of modal interstitial phases. We observed a correlated evolution of textural parameters in olivine at increasing amount of melt impregnation, namely a progressive increase of the number of grains, decreasing grain size and a decrease in the shape factor and aspect ratio of the grains. Overall, this textural evolution is indicative of a dismembering of corroded mantle olivine grains into several small rounded grains (low shape factor and aspect ratio), caused by reactive melt percolation and crystallization. These observations confirm the possible hybrid origin of troctolites after impregnation of an olivine matrix, and quantify the evolution of the texture and dismembering of olivines after melt-related corrosion. Boudier, F., Nicolas, A. (1995) Nature of the Moho Transition Zone in the Oman Ophiolite, Journal of Petrology,36:777-796. Drouin, M., Ildefonse, B., Godard, M. (2010) A microstructural imprint of melt impregnation in slow spreading lithosphere: Olivine-rich troctolites from the Atlantis Massif, Mid-Atlantic Ridge, 30°N, IODP Hole U1309D, Geochem. Geophys. Geosyst., 11, Q06003, doi:10.1029/2009GC002995. Rampone, E., Piccardo, G.B., Hofmann, A.W. (2008) Multi-stage melt-rock interaction in the Mt. Maggiore (Corsica, France) ophiolitic peridotites: microstructural and geochemical evidence, Contributions to Mineralogy and Petrology, 156:453-475, doi: 10.1007/s00410-008-0296-y Sanfilippo, A., Morishita, T., Kumagai, H., Nakamura, K., Okino, K., Hara, K., Tamura, A., Arai, S. (2015) Hybrid troctolites from Mid-Ocean Ridges: Inherited mantle in the lower crust, Lithos, doi: 10.1016/j.lithos.2015.06.025

Paleointensities of the Auckland Excursion from Volcanic Rocks in New Zealand

NASA Astrophysics Data System (ADS)

Mochizuki, N.; Tsunakawa, H.; Shibuya, H.; Cassidy, J.; Smith, I. E.

2001-12-01

Shibuya et al. (1992) reported the Auckland excursion from several basaltic lava flows of monogenetic volcanic centers (<50 ka) in the Auckland Volcanic Field, New Zealand. The Auckland excursion was recorded in five centers in three intermediate direction groups of north-down, west and south. We carried out paleointensity and rock-magnetic studies in order to obtain the absolute paleointensities associated with three intermediate geomagnetic fields. Thermomagnetic analyses indicated typical Curie temperatures of 150-200, 450-500 and/or 550-580 oC. The Day plot (Day et al., 1977) showed a linear trend in the pseudo-single-domain range of magnetic carriers. Those results, combined with the reflection microscope observations, identified the magnetic carriers as titanomagnetites with wide variation in titanium content and grain size. First, the Coe's version of the Thellier method (Coe, 1967) was applied to the samples. Several samples seemed to give paleointensities ranging from 3.2 to 6.4 μ T (Shibuya and Cassidy, 1995 AGU fall meeting), but they were often affected by thermal alteration in the furnace even from fairly low temperature steps like 200oC. We were forced to introduce correction for thermal alterations in laboratory heating, using low temperature part of the Arai plot. We, therefore, applied the double heating technique (DHT) of Shaw method (Tsunakawa and Shaw, 1994), which was capable of detecting inappropriate results by the ARM correction, to the samples. The low temperature demagnetization (LTD) was combined with DHT (Yamamoto et al., submitted) before AF demagnetization and samples were heated in a vacuum of 10-100 Pa. Sixty-one samples from the five lava flows were subjected to the LTD-DHT Shaw method. Twenty-three of these samples yielded successful results passing the selection criteria. Five out of six paleointensities from the Crater Hill lava were consistent with each other. A mean paleointensity was given to be 10.9+/- 1.9 μ T (N=5) for the

PREFACE: The 15th International Conference on X-ray Absorption Fine Structure (XAFS15)

NASA Astrophysics Data System (ADS)

Wu, Z. Y.

2013-04-01

Committees and Staff Chair of the Conference Ziyu Wu International Advisory Committee Adam Hitchcock, Canada Adriano Filipponi, Italy Alain Manceau, France Alexander Soldatov, Russia Andrea Di Cicco, Italy Britt Hedman, USA Bruce Bunker, USA Calogero R. Natoli, Italy Christopher T. Chantler, Australia Frank M. F. De Groot, Netherlands Hiroyuki Oyanagi, Japan Ingolf Lindau, USA J. Mustre de Leon, México James E Penner-Hahn, USA Joaquin Garcia Ruiz, Spain John Evans, UK John J. Rehr, USA Kiyotaka Asakura, Japan Majed Chergui, Switzerland Mark Newton, UK Shiqiang Wei, P. R. China Tsun-Kong Sham, Canada Ziyu Wu, P. R. China International Program Committee Antonio Bianconi, Italy Augusto Marcelli, Italy Emad Flear Aziz, Germany Jinghua Guo, USA Joly Yves, France Masaharu Nomura, Japan Maurizio Benfatto, Italy Pieter Glatzel, France Shiqiang Wei, China Tiandou Hu, China Toshihiko Yokoyama, Japan Way-Faung Pong, Taiwan Xinyi Zhang, China Yi Xie, China Yuying Huang, China Zhonghua Wu, China Ziyu Wu, China Local Organizing Committee Bo He Fengchun Hu Haifeng Zhao Jing Zhang Meijuan Yu Qin Yu Shuo Zhang Wangsheng Chu Wei He Wei Xu Wensheng Yan Xiaomei Gong Xing Chen Yang Zou Yi Xia Zheng Jiang Zhi Xie Zhihu Sun Zhiyun Pan Additional Staff Chengxun Liu

PREFACE: Ultrathin layers of graphene, h-BN and other honeycomb structures Ultrathin layers of graphene, h-BN and other honeycomb structures

NASA Astrophysics Data System (ADS)

Geber, Thomas; Oshima, Chuhei

2012-08-01

nanometer scale. This special section contains interesting papers on graphene, h-BN and related 'honeycomb' compounds on solid surfaces, which are currently in development. Interfacial interaction strongly modifies the electronic and atomic structures of these overlayer systems and substrate surfaces. In addition, one can recognize a variety of growth phenomena by changing the surface and growth conditions, which are promising as regards fabricating those noble nanosystems. We have great pleasure in acknowledging the enthusiastic response and participation of our invited authors and their diligent preparation of the manuscripts. Ultrathin layers of graphene, h-BN and other honeycomb structures contents Ultrathin layers of graphene, h-BN and other honeycomb structuresThomas Geber and Chuhei Oshima Templating of arrays of Ru nanoclusters by monolayer graphene/Ru Moirés with different periodicitiesEli Sutter, Bin Wang, Peter Albrecht, Jayeeta Lahiri, Marie-Laure Bocquet and Peter Sutter Controllable p-doping of graphene on Ir(111) by chlorination with FeCl3N A Vinogradov, K A Simonov, A V Generalov, A S Vinogradov, D V Vyalikh, C Laubschat, N Mårtensson and A B Preobrajenski Optimizing long-range order, band gap, and group velocities for graphene on close-packed metal surfacesF D Natterer, S Rusponi, M Papagno, C Carbone and H Brune Epitaxial growth of graphene on transition metal surfaces: chemical vapor deposition versus liquid phase depositionSamuel Grandthyll, Stefan Gsell, Michael Weinl, Matthias Schreck, Stefan Hüfner and Frank Müller High-yield boron nitride nanosheets from 'chemical blowing': towards practical applications in polymer compositesXuebin Wang, Amir Pakdel, Chunyi Zhi, Kentaro Watanabe, Takashi Sekiguchi, Dmitri Golberg and Yoshio Bando BCx layers with honeycomb lattices on an NbB2(0001) surfaceChuhei Oshima Epitaxial growth of boron-doped graphene by thermal decomposition of B4CWataru Norimatsu, Koichiro Hirata, Yuta Yamamoto, Shigeo Arai and Michiko

EDITORIAL: On display with transparent conducting films On display with transparent conducting films

NASA Astrophysics Data System (ADS)

Demming, Anna

2012-03-01

the sheet resistance of HNO3 treated carbon-nanotube films than the removal of residual N-methylpyrrolidone. Unsurprisingly graphene, the latest carbon wonder material, has also shown remarkable potential as a transparent conducting film. Chemical vapour deposition (CVD) synthesis of graphene has the advantage that it allows fabrication of the sheets to be scaled up. A collaboration of researchers in the USA, Singapore and Korea demonstrated that the conductivity of CVD graphene sheets can be improved by p-doping with AuCl3 [9]. The potential of graphene in a range of applications is also being demonstrated, as researchers in Australia and China show in a report on graphene in transparent conducting electrodes for GaN LED devices [10]. The review in this issue [4] provides a comprehensive overview of graphene as an electrode, including the synthesis, chemical doping and work function engineering of the material, as well as applications in transistors, memories, molecular junctions, touch screens, LCDs, LEDs and solar cells. Back in the early 1950s Gillham and Preston saw the possibility of using their gold sputtered bismuth oxide films for windows that could be electrically heated and took out a patent on their discovery [11]. While they saw potential applications for conducting transparent films, it could be argued that even Gillham and Preston would have been surprised at the extent to which transparent conducting films have infiltrated everyday technology over the 60 years since. It is tempting to wonder what wide reaching ramifications the current fruitful activity in graphene device research may have in the decades to come. References [1] Ayrton W E and Mather T 1894 J. Int. Elec. Eng. 23 376-80 [2] Gillham E J and Preston J S 1952 Proc. Phys. Soc. B 65 649 [3] Ishiguro K, Sasaki T, Arai T and Imai I 1958 J. Phys. Soc. Jpn. 13 296-304 [4] Jo G, Choe M, Lee S, Park W, Kahng Y H and Lee T 2012 Nanotechnology 23 112001 [5] Guo P and Aegerter M A 1999 Thin Solid

Abass Alavi: A giant in Nuclear Medicine turns 80 and is still going strong!

PubMed

Høilund-Carlsen, Poul F

2018-01-01

him one of the most cited researchers at the University of Pennsylvania with a production of more than 1,200 articles, a similar number of published abstracts and close to 58,000 citations according to Google Scholar, of which about 20,000 since 2012 when he was 74. This is just part of an amazing story. Having turned to nuclear medicine in 1971, Alavi entered into one of the World's most ingenious and productive medical research en-vironments comprising collaboration of experts in nuclear medicine (David Kuhl) and neurology (Martin Reivich) at Penn, and in physiology and pharmacology (Louis Sokoloff) at the NIH, all of whom contributed significantly to the development of PET. Focus was on cerebral research with beta-emitting 14 C-labeled deoxyglucose for mapping regional cerebral glucose metabolism by means of autoradiography. Alavi became a junior member of this collaboration in which the idea of labeling deoxyglucose with a gamma-emitting isotope arose to allow in vivo examination of the normal and diseased human brain. They contacted Alfred Wolf at Brookhaven National Laboratory who had an interest in synthesizing positron-emitting compounds. He suggested labeling instead with 18 F-FDG and in 1975 Wolf's group including Tatsuo Ido and Joanna Fowler succeeded in synthesizing 18 F-FDG. In the meantime, investigators at Penn had developed high energy collimators for the Mark IV scanner to allow imaging with 18 F-FDG, so in August 1976, two normal volunteers were the first to receive a dose of 18 F-FDG for tomographic brain imaging showing concentration of 18 F-FDG in the gray matter while in one volunteer a "whole-body" scan from the top of the scull to mid-thigh was also obtained. A year before, investigators at Washington University, i.e., Michel Ter-Pogossian in collaboration with Michael Phelps, Edward Hoffmann, and Nizar Mullani had developed what they termed a positron-emission transaxial tomograph for nuclear imaging, i.e. a machine which was the starting