Sample records for aart-jriado jri lehtsaar
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Houwink, Annemieke; Geerdink, Yvonne A; Steenbergen, Bert; Geurts, Alexander C H; Aarts, Pauline B M
2013-01-01
To investigate the validity and reliability of the revised Video-Observation Aarts and Aarts module: Determine Developmental Disregard (VOAA-DDD-R). Upper-limb capacity and performance were assessed in children with unilateral spastic cerebral palsy (CP) by measuring overall duration of affected upper-limb use and the frequency of specific behaviours during a task in which bimanual activity was demanded ('stringing beads') and stimulated ('decorating a muffin'). Developmental disregard was defined as the difference in duration of affected upper-limb use between both tasks. Raters were two occupational and one physical therapist who received 3 hours of training. Construct validity was determined by comparing children with CP with typically developing children. Intrarater, interrater, and test-retest reliability were determined using the intraclass correlation coefficient. Standard errors of measurement and smallest detectable differences were also calculated. Twenty-five children with CP (15 females, 10 males; mean age 4 y 9 mo [SD 1 y 7 mo], range 2 y 9 mo-8 y; Manual Ability Classification System levels I-III) scored lower on capacity (p=0.052) and performance (p<0.001), and higher on developmental disregard (p<0.001) than 46 age- and sex-matched typically developing children (23 males; mean age 5 y 3 mo [SD 1 y 5 mo], range 2 y 6 mo-8 y). The intraclass correlation coefficients (0.79-1.00) indicated good reliability. Absolute agreement was high, standard errors of measurement ranged from 4.5 to 6.8%, and smallest detectable differences ranged from 12.5 to 19.0%. The VOAA-DDD-R can be reliably and validly used by occupational and physical therapists to assess upper-limb capacity, performance, and developmental disregard in children (2 y 6 mo-8 y) with CP. © The Authors. Developmental Medicine & Child Neurology © 2012 Mac Keith Press.
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New species of Ipomoea (Convolvulaceae) from South America
Wood, John R.I.; Muñoz-Rodríguez, Pablo; Degen, Rosa; Scotland, Robert W.
2017-01-01
Abstract The importance of discovering, describing and cataloguing poorly known species in herbarium collections is discussed. It is a spur to efforts at rediscovery and consequent conservation efforts. The problems faced in describing species from limited material are discussed and our methods and criteria in making a decision are described. Prospects for future novelties are briefly assessed. Fifteen new species are described and illustrated with line drawings and distribution maps: Ipomoea attenuata J.R.I. Wood & Scotland, I. cuscoensis J.R.I. Wood & P. Muñoz, I. dasycarpa J.R.I. Wood & Scotland, I. dolichopoda J.R.I. Wood & R. Degen, I. ensiformis J.R.I.Wood & Scotland, I. fasciculata J.R.I. Wood & Scotland, I. graminifolia J.R.I. Wood & Scotland, I. kraholandica J.R.I. Wood & Scotland, I. longirostra J.R.I. Wood & Scotland, I. revoluta J.R.I. Wood & Scotland, I. scopulina J.R.I. Wood &. Scotland, I. uninervis J.R.I. Wood & Scotland, I. veadeirosii J.R.I. Wood & Scotland, I. velutinifolia J.R.I. Wood & Scotland, I. walteri J.R.I. Wood & Scotland. All species are narrow endemics except I. velutinifolia which is found in Brazil and Peru; of the others, 12 are found in Brazil and one each in Paraguay and Peru. PMID:29118645
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ERIC Educational Resources Information Center
US Department of Education, 2010
2010-01-01
The Association of Advanced Rabbinical and Talmudic Schools, Accreditation Commission (AARTS) accredits advanced rabbinical and Talmudic institutions that grant postsecondary degrees such as the baccalaureate, master's, doctorate, first rabbinic, and first Talmudic degrees. AARTS-accredited schools offer a program of Talmud and related studies.…
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Demonstration of Laser Plasma X-Ray Source with X-Ray Collimator Final Report CRADA No. TC-1564-99
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lane, S. M.; Forber, R. A.
2017-09-28
This collaborative effort between the University of California, Lawrence Livermore National Laboratory (LLNL) and JMAR Research, Inc. (JRI), was to demonstrate that LLNL x-ray collimators can effectively increase the wafer throughput of JRI's laser based x-ray lithography systems. The technical objectives were expected to be achieved by completion of the following tasks, which are separated into two task lists by funding source. The organization (LLNL or JMAR) having primary responsibility is given parenthetically for each task.
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Refracted Acoustic Communications in Wireless Underwater Sensor Networks with Mobility
2015-07-01
presented in ( Nicolaou et al., 2007). Depth measurement ca- pability is assumed in depth-based routing schemes (Hasannezhad et al., 2014). Awareness of...Ri cosαk )2 = (di j Ri tanαk)2+(Δzi j+Ri)2 R2i cos2αk = d2i j 2di jRi tanαk+R 2 i tan 2αk+ . . . (Δzi j)2+2Δzi jRi+R2i Grouping all R2i terms on the...1754–1757. Lurton, X. (2010). An Introduction to Underwater Acoustics. Springer-Verlag, Berlin, 2nd edition. Nicolaou , N., See, A., Cui, J., and
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NASA Astrophysics Data System (ADS)
Ho, Ching S.; Liou, Juin J.; Georgiopoulos, Michael; Christodoulou, Christos G.
1994-03-01
This paper presents an analog circuit design and implementation for an adaptive resonance theory neural network architecture called the augmented ART1 neural network (AART1-NN). Practical monolithic operational amplifiers (Op-Amps) LM741 and LM318 are selected to implement the circuit, and a simple compensation scheme is developed to adjust the Op-Amp electrical characteristics to meet the design requirement. A 7-node prototype circuit has been designed and verified using the Pspice circuit simulator run on a Sun workstation. Results simulated from the AART1-NN circuit using the LM741, LM318, and ideal Op-Amps are presented and compared.
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High-resolution airborne gravity imaging over James Ross Island (West Antarctica)
Jordan, T.A.; Ferraccioli, F.; Jones, P.C.; Smellie, J.L.; Ghidella, M.; Corr, H. F. J.; Zakrajsek, A.F.
2007-01-01
James Ross Island (JRI) exposes a Miocene-Recent alkaline basaltic volcanic complex that developed in a back-arc, east of the northern Antarctic Peninsula. JRI has been the focus of several geological studies because it provides a window on Neogene magmatic processes and paleoenvironments. However, little is known about its internal structure. New airborne gravity data were collected as part of the first high-resolution aerogeophysical survey flown over the island and reveal a prominent negative Bouguer gravity anomaly over Mt Haddington. This is intriguing as basaltic volcanoes are typically associated with positive Bouguer anomalies, linked to underlying mafic intrusions. The negative Bouguer anomaly may be associated with a hitherto unrecognised low-density sub-surface body, such as a breccia-filled caldera, or a partially molten magma chamber.
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NASA Technical Reports Server (NTRS)
Hollingsworth, Jeffery L.; Bridger, Alison F. C.; Haberle, Robert M.
1999-01-01
This is a Final Report for a Joint Research Interchange (JRI) between NASA Ames Research Center and San Jose State University, Department of Meteorology. We present below a summary of progress made during the duration of this JRI. The focus of this JRI has been to investigate seasonal water vapor transport in the atmosphere of Mars and its effects on the planet's present climate. To this end, the primary task has been to adapt a new dynamical processor for the adiabatic tendencies of the atmospheric circulation into the NASA Ames Mars general circulation model (MGCM). Using identical boundary and initial conditions, several comparative tests between the new and old MGCMs have been performed and the nature of the simulated circulations have been diagnosed. With confidence that the updated version of the Ames MGCM produces quite similar mean and eddy circulation statistics, the new climate model is well poised as a tool to pursue fundamental questions related to the spatial and seasonal variations of atmospheric water vapor on Mars, and to explore exchanges of water with non-atmospheric reservoirs and transport within its atmosphere. In particular, the role of surface sources and sinks can be explored, the range of water-vapor saturation altitudes can be investigated, and plausible precipitation mechanisms can be studied, for a range of atmospheric dust loadings. Such future investigations can contribute to a comprehensive study of surface inventories, exchange mechanisms, and the relative importance of atmospheric transport Mars' water cycle. A listing of presentations made and manuscripts submitted during the course of this project is provided.
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NASA Technical Reports Server (NTRS)
Hollingsworth, Jeffery L.; Bridger, Alison F. C.; Haberle, Robert M.
1999-01-01
This is a Final Report for a Joint Research Interchange (JRI) between NASA Ames Research Center and San Jose State University, Department of Meteorology. We present below a summary of progress made during the duration of this JRI. The focus of this JRI has been to investigate seasonal water vapor transport in the atmosphere of Mars and its effects on the planet's present climate. To this end, the primary task has been to adapt a new dynamical processor for the adiabatic tendencies of the atmospheric circulation into the NASA Ames Mars general circulation model (MGCM). Using identical boundary and initial conditions, several comparative tests between the new and old MGCMs have been performed and the nature of the simulated circulations have been diagnosed. With confidence that the updated version of the Ames MGCM produces quite similar mean and eddy circulation statistics, the new climate model is well poised as a tool to pursue fundamental questions related to the spatial and seasonal variations of atmospheric water vapor on Mars, and to explore exchanges of water with non-atmospheric reservoirs and transport within its atmosphere. In particular, the role of surface sources and sinks can be explored, the range of water-vapor saturation altitudes can be investigated, and plausible precipitation mechanisms can be studied, for a range of atmospheric dust loadings, such future investigations can contribute to a comprehensive study of surface inventories, exchange mechanisms, and the relative importance of atmospheric transport Mars' water cycle. A listing of presentations made and manuscripts submitted during the course of this project is provided.
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Seven big strike-slip earthquakes
NASA Astrophysics Data System (ADS)
Lohman, R. B.; Simons, M.; Pritchard, M. E.
2003-12-01
We examine seven large (Mw > 7) strike-slip earthquakes that occurred since the beginning of ERS 1 and 2 missions. We invert GPS observations and InSAR interferograms and azimuth offsets for coseismic slip distributions. We explore two refinements to the traditional least-squares inversion technique with roughness constraints. First, we diverge from the usual definition of ``roughness'' as the average roughness over the entire fault plane, and allow ``variable smoothing'' constraints. Variable smoothing allows our inversion to select models that are more complex in regions that are well-resolved by the data, while still damping regions that are poorly resolved. Second, we choose our smoothing parameters using the jR_i criterion. The jR_i criterion draws on the theory behind cross-validation and the bootstrap method. We examine the theoretical basis behind such methods and use an analytical approximation technique for linear problems. We provide maps of model variance and spatial averaging scale over the fault plane, to explicitly show which features in our slip models are robust. We examine the 1992 Landers (CA), 1995 Sakhalin (Russia), 1995 Kobe (Japan), 1997 Ardekul (Iran), 1997 Manyi (Tibet), 1999 Hector Mine (CA), and 2001 Kunlun (Tibet) earthquakes. We compare features of the slip distributions such as the depth distribution of slip, the inferred magnitude and the degree of heterogeneity of slip over the fault plane, as resolved by the available InSAR and GPS data. We end with a brief description of the data coverage required for future earthquakes of similar size if we want to infer some of the above quantities to within a given confidence interval. We describe both the number of InSAR scenes and the distribution of GPS points that would be required, based on theoretical treatments of the fault plane/data point geometry using the jR_i method.
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NASA Astrophysics Data System (ADS)
Massam, A.; Mulvaney, R.; McConnell, J.; Abram, N.; Arienzo, M. M.; Whitehouse, P. L.
2016-12-01
The James Ross Island ice core, drilled to 364 m on the northern tip of the Antarctic Peninsula, preserves a climate record that spans beyond the Holocene period to the end of the last glacial maximum (LGM). Reanalysis of the ice core using high-resolution continuous flow analysis (CFA) highlighted errors in the identification of events of known age that had been used to constrain the earlier chronology. The new JRI2 chronology is annual layer counted to 300 years, with the remaining profile reconstructed using a new age-depth model that is tied to age horizons identified in the annual-layer counted WAIS Divide ice core record. An accurate age-depth profile requires reliable known-age horizons along the ice core profile. In addition, these allow us to determine a solution for the accumulation history and rate of compaction due to vertical strain. The accuracy of the known-age constraints used in JRI2 allows only a small uncertainty in the reconstruction of the most recent 2000 years of accumulation variability. Independently, the surface temperature profile has been estimated from the stable water isotope profile and calibrated to borehole temperature observations. We present the accumulation, vertical thinning and temperature history interpreted from the James Ross Island ice core for the most recent 2000 years. JRI2 reconstructions show accumulation variability on a decadal to centennial timescale up to 20% from the present-day mean annual accumulation rate of 0.63 m yr-1. Analysis of the accumulation profile for James Ross Island offers insight into the sensitivity of accumulation to a change in surface temperature, as well as the reliability of the assumed relationship between accumulation and surface temperature in climate reconstructions using stable water isotope proxies.
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An Intercomparison of the Dynamical Cores of Global Atmospheric Circulation Models for Mars
NASA Technical Reports Server (NTRS)
Hollingsworth, Jeffery L.; Bridger, Alison F. C.; Haberle, Robert M.
1998-01-01
This is a Final Report for a Joint Research Interchange (JRI) between NASA Ames Research Center and San Jose State University, Department of Meteorology. The focus of this JRI has been to evaluate the dynamical 'cores' of two global atmospheric circulation models for Mars that are in operation at the NASA Ames Research Center. The two global circulation models in use are fundamentally different: one uses spherical harmonics in its horizontal representation of field variables; the other uses finite differences on a uniform longitude-latitude grid. Several simulations have been conducted to assess how the dynamical processors of each of these circulation models perform using identical 'simple physics' parameterizations. A variety of climate statistics (e.g., time-mean flows and eddy fields) have been compared for realistic solstitial mean basic states. Results of this research have demonstrated that the two Mars circulation models with completely different spatial representations and discretizations produce rather similar circulation statistics for first-order meteorological fields, suggestive of a tendency for convergence of numerical solutions. Second and higher-order fields can, however, vary significantly between the two models.
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An Intercomparison of the Dynamical Cores of Global Atmospheric Circulation Models for Mars
NASA Technical Reports Server (NTRS)
Hollingsworth, Jeffery L.; Bridger, Alison F. C.; Haberle, Robert M.
1998-01-01
This is a Final Report for a Joint Research Interchange (JRI) between NASA Ames Research Cen- ter and San Jose State University, Department of Meteorology. The focus of this JRI has been to evaluate the dynamical "cores" of two global atmospheric circulation models for Mars that are in operation at the NASA Ames Research Center. ne two global circulation models in use are fundamentally different: one uses spherical harmonics in its horizontal representation of field variables; the other uses finite differences on a uniform longitude-latitude grid. Several simulations have been conducted to assess how the dynamical processors of each of these circulation models perform using identical "simple physics" parameterizations. A variety of climate statistics (e.g., time-mean flows and eddy fields) have been compared for realistic solstitial mean basic states. Results of this research have demonstrated that the two Mars circulation models with completely different spatial representations and discretizations produce rather similar circulation statistics for first-order meteorological fields, suggestive of a tendency for convergence of numerical solutions. Second and higher-order fields can, however, vary significantly between the two models.
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An Evaluation of an Ada Implementation of the Rete Algorithm for Embedded Flight Processors
1990-12-01
computers was desired. The VAX VMS operating system has many built-in methods for determining program performance (including VAX PCA), but these methods... overviev , of the target environment-- the MIL-STD-1750A VHSIC Avionic Modular Processor ( VA.IP, running under the Ada Avionics Real-Time Software (AARTS... computers . Mil-STD-1750A, the Air Force’s standard flight computer architecture, however, places severe constraints on applications software processing
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A Propagator Expansion Method for Solving Linearized Plasma Kinetic Equations with Collisions.
1984-06-25
of the collision frequency. For the linearized Balescu -Lenard collision * operator and for the zero-order distribution function Maxwellian, we obtain...Rev. 94:511. 3. Lenard, A. , and Bernstein, 1. 13. (1958) Phys. Rev. 112:1456. 4. Dougherty, J. P. (1964) Phys. Fluids 7:1788. 5. Balescu , R. (1960...long wavelength limit for the linearized Balescu - Lenard collision operator and for f0 Maxwellian. We obLain the total L damping rate 1 jry which is
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1942-01-01
ES) 10. SPONSOR/MONITOR’S ACRONYM(S) 11. SPONSOR/MONITOR’S REPORT NUMBER(S) 12. DISTRIBUTION/AVAILABILITY STATEMENT Approved for public release ...1. Dinglf Drill. ............. 67 2. DiBfhy Equipment. ............ 57 S. Aboard tlie life»Raft. ......... 68 4. Rationing of Food aart Water...fl 4. PUats ................ f4 5. Pood front Pr«»fc V«t«r. ........ 7* 8. Food Alonf Shore ........... 76 f. Skcll Pith .............. fi 8. Birds
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An Evaluation of a Modified Simulated Annealing Algorithm for Various Formulations
1990-08-01
trials of the K"h Markov chain, is sufficiently close to q(c, ), the stationary distribution at ck la (Lk,c,,) - q(c.) < epsilon Requiring the final...Wiley and Sons . Aarts, E. H. L., & Van Laarhoven, P. J. M. (1985). Statistical cooling: A general approach to combinatorial optimization problems...Birkhoff, G. (1946). Tres observaciones sobre el algebra lineal, Rev. Univ. Nac. TucumanSer. A, 5, 147-151. Bohr, Niels (1913). Old quantum theory
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Intraseasonal and Interannual Variability of Mars Present Climate
NASA Astrophysics Data System (ADS)
Hollingsworth, Jeffery L.; Bridger, Alison F. C.; Haberle, Robert M.
1996-01-01
This is a Final Report for a Joint Research Interchange (JRI) between NASA Ames Research Center and San Jose State University, Department of Meteorology. The focus of this JRI has been to investigate the nature of intraseasonal and interannual variability of Mars'present climate. We have applied a three-dimensional climate model based on the full hydrostatic primitive equations to determine the spatial, but primarily, the temporal structures of the planet's large-scale circulation as it evolves during a given seasonal advance, and, over multi-annual cycles. The particular climate model applies simplified physical parameterizations and is computationally efficient. It could thus easily be integrated in a perpetual season or advancing season configuration, as well as over many Mars years. We have assessed both high and low-frequency components of the circulation (i.e., motions having periods of Omicron(2-10 days) or greater than Omicron(10 days), respectively). Results from this investigation have explored the basic issue whether Mars' climate system is naturally 'chaotic' associated with nonlinear interactions of the large-scale circulation-regardless of any allowance for year-to-year variations in external forcing mechanisms. Titles of papers presented at scientific conferences and a manuscript to be submitted to the scientific literature are provided. An overview of a areas for further investigation is also presented.
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Advancing Air Force Scheduling through Modeling Problem Topologies
2006-08-03
Merrill on August 23, 2005 and corresponded with Major David Van Veldhuizen in Fall 2005 about obtaining data. 3.4.3 Transitions Analytical Graphics and...observation satellite orbit. Technical Report CRT-2003-27, Centre de recherche sur les transports, July 2003. [5] Van -Dat Cung. ROADEF 2003: Results of the...collaborateurs/etd/default.htm. January, 2004. [15] P.J.M van Laarhoven, E.H.L. Aarts, and J.K. Lenstra. Job shop scheduling by simulated annealing
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A System Approach to Navy Medical Education and Training. Appendix 20. Ophthalmology Technician.
1974-08-31
PAGE 02 I OF RESDONSE BOOKLET I ISCRFN PATIENT O4 ARRIVAL TO DETERMINE WHICH STAFF MEMBER IPATIENT SHOULD SEE 2 ICHECK PUPIL REACTION TO LIGHT 3 IDILATE...PUPILS 4 IPALPATE EYi FOR INTRAOCULAR TENSION 5 IOBSERVE/RECORD OR DESCRIBE CHARACTERISTICS OF DRAINAGE FROM IEYES/EARS I 6 IOBSERVE FOR REPORT OR...RINGING, HEARI’iG ILOSS 1 38 !OBSERVE/RECORD OR DESCRIBE CHARACTERISTICS OF SI,ITUM, MUCUS 39 1EXAMINE FOR VIRAL INFECTIONS OF THE SKIN, E.G. AARTS 40
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Metallurgical Examination of a Cast Turret Manufactured by the American Steel Foundries
1945-03-28
ferrite and a structure stmlar to tempered bainite tnd fine carb ides. 4. The results of this investigatio l inCicate that the American Steel Foundries...1hirrot No 11Mufac t~redj~ t!Le American~ Steel Poidcries J.J Wil jr;I 4?1 ’JJ No. B171; 11000 Picral Structure simuilar to temnpered bainite Lavsociated wita fine carbides and ferrite patcha.. FIGM I ...examination has been conducted on two samples of the. cast turret to. 3171 for the Hedium Tank II4, maiufactured by the i.meriaan Steel Foundries, which
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Soil thermal properties at two different sites on James Ross Island in the period 2012/13
NASA Astrophysics Data System (ADS)
Hrbáček, Filip; Láska, Kamil
2015-04-01
James Ross Island (JRI) is the largest island in the eastern part of the Antarctic Peninsula. Ulu Peninsula in the northern part of JRI is considered the largest ice free area in the Maritime Antarctica region. However, information about permafrost on JRI, active layer and its soil properties in general are poorly known. In this study, results of soil thermal measurements at two different sites on Ulu Peninsula are presented between 1 April 2012 and 30 April 2013. The study sites are located (1) on an old Holocene marine terrace (10 m a. s. l.) in the closest vicinity of Johann Gregor Mendel (JGM) Station and (2) on top of a volcanic plateau named Johnson Mesa (340 m a. s. l.) about 4 km south of the JGM Station. The soil temperatures were measured at 30 min interval using platinum resistance thermometers Pt100/8 in two profiles up to 200 cm at JGM Station and 75 cm at Johnson Mesa respectively. Decagon 10HS volumetric water content sensors were installed up 30 cm at Johnson Mesa to 50 cm at JGM Station, while Hukseflux HFP01 soil heat flux sensors were used for direct monitoring of soil physical properties at 2.5 cm depth at both sites. The mean soil temperature varied between -5.7°C at 50 cm and -6.3°C at 5 cm at JGM Station, while that for Johnson Mesa varied between -6.9°C at 50 cm and -7.1°C at 10 cm. Maximum active layer thickness estimated from 0 °C isotherm reached 52 cm at JGM Station and 50 cm at Johnson Mesa respectively which corresponded with maximum observed annual temperature at 50 cm at both sites. The warmest part of both profiles detected at 50 cm depth corresponded with maximum thickness of active layer, estimated from 0°C isotherm, reached 52 cm at JGM Station and 50 cm at Johnson Mesa respectively. Volumetric water content at 5 cm varied around 0.25 m3m-3 at both sites. The slight increase to 0.32 m3m-3 was observed at JGM Station at 50 cm and at Johnson Mesa at 30 cm depth. Soil texture analysis showed distinctly higher share of coarser
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Aarts, Pauline B M; Jongerius, Peter H; Geerdink, Yvonne A; Geurts, Alexander C
2009-11-25
In 2003 new computer software, the VOAA (Video Observations Aarts and Aarts), was designed to score and evaluate two important aspects of spontaneous upper limb use, i.e. overall duration and frequency of specific behaviours. The aim of this study was to investigate the test-retest, interrater and intrarater reliability and the construct validity of a new module, the VOAA-DDD, to determine developmental disregard in children with spastic unilateral cerebral palsy (CP). A test-retest design with three raters for reliability and a two-group design for construct validity were used. Subjects were a total of 20 children with spastic unilateral CP equally divided in two age groups (2.5-5 and 5-8 years), and 56 healthy children of the same age groups. Overall duration and frequency of specific behaviours of the affected arm and hand were assessed during a task demanding ('stringing beads') and a task stimulating ('decorating a muffin') the use of both hands. Reliability was estimated by intraclass correlation coefficients (ICCs). Construct validity was assessed by comparing children with CP to healthy children. All ICCs exceeded 0.87. In contrast with healthy children, children with CP used their affected hand less during the 'muffin' task compared to the 'beads' task. Of the children with CP, 90% in the age group of 2.5-5 years and 50% in the age group of 5-8 years showed values exceeding the extreme values of healthy controls, respectively, indicating developmental disregard. The VOAA-DDD is a reliable and valid instrument to assess spontaneous use of the affected arm and hand in order to determine developmental disregard in children with spastic unilateral CP.
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Turbine Engine Control Synthesis. Volume 2. Simulation and Controller Software
1975-03-01
22141 0075 0 0010 129 ST039 DC 16 0076 0 FOAO 130 ST04o nr -3936 N GAIN 1OOtE) 0077 0 0670 131 T51041 C 1648 Wf l- ( 100 ,E) - - "Ŕ--8--1FA4-- 132...Calculation 131 Equilibrium- Temperature Software 131 Initialization 132 Interpolation Interval Determination 132 Interpolation Logic 133 Filtering Logic...eNJC1 131 : * PP3.(t..PSTPbNiR(A)/TV3).U1-• 025: •v53T.KUAL-;w)*(- 4-Pt5 133: * TV*/,V4 Irflw# * S TTcTv*/18.7) 13s: v3 L’s rtVcLL,(4)aArt IaJV44/(3RTh44
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NASA Astrophysics Data System (ADS)
Capron, E.; Landais, A.; Buiron, D.; Cauquoin, A.; Chappellaz, J. A.; Debret, M.; Jouzel, J.; Leuenberger, M.; Martinerie, P.; Masson-Delmotte, V.; Mulvaney, R.; Parrenin, F.; Prié, F.
2013-12-01
Correct estimation of the firn lock-in depth is essential for correctly linking gas and ice chronologies in ice core studies. Here, two approaches to constrain the firn depth evolution in Antarctica are presented over the last deglaciation: outputs of a firn densification model, and measurements of δ15N of N2 in air trapped in ice core, assuming that δ15N is only affected by gravitational fractionation in the firn column. Since the firn densification process is largely governed by surface temperature and accumulation rate, we have investigated four ice cores drilled in coastal (Berkner Island, BI, and James Ross Island, JRI) and semi-coastal (TALDICE and EPICA Dronning Maud Land, EDML) Antarctic regions. Combined with available ice core air- δ15N measurements from the EPICA Dome C (EDC) site, the studied regions encompass a large range of surface accumulation rates and temperature conditions. Our δ15N profiles reveal a heterogeneous response of the firn structure to glacial-interglacial climatic changes. While firn densification simulations correctly predict TALDICE δ15N variations, they systematically fail to capture the large millennial-scale δ15N variations measured at BI and the δ15N glacial levels measured at JRI and EDML - a mismatch previously reported for central East Antarctic ice cores. New constraints of the EDML gas-ice depth offset during the Laschamp event (41 ka) and the last deglaciation do not favour the hypothesis of a large convective zone within the firn as the explanation of the glacial firn model- δ15N data mismatch for this site. While we could not conduct an in-depth study of the influence of impurities in snow for firnification from the existing datasets, our detailed comparison between the δ15N profiles and firn model simulations under different temperature and accumulation rate scenarios suggests that the role of accumulation rate may have been underestimated in the current description of firnification models.
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NASA Astrophysics Data System (ADS)
Capron, E.; Landais, A.; Buiron, D.; Cauquoin, A.; Chappellaz, J.; Debret, M.; Jouzel, J.; Leuenberger, M.; Martinerie, P.; Masson-Delmotte, V.; Mulvaney, R.; Parrenin, F.; Prié, F.
2013-05-01
Correct estimation of the firn lock-in depth is essential for correctly linking gas and ice chronologies in ice core studies. Here, two approaches to constrain the firn depth evolution in Antarctica are presented over the last deglaciation: outputs of a firn densification model, and measurements of δ15N of N2 in air trapped in ice core, assuming that δ15N is only affected by gravitational fractionation in the firn column. Since the firn densification process is largely governed by surface temperature and accumulation rate, we have investigated four ice cores drilled in coastal (Berkner Island, BI, and James Ross Island, JRI) and semi-coastal (TALDICE and EPICA Dronning Maud Land, EDML) Antarctic regions. Combined with available ice core air-δ15N measurements from the EPICA Dome C (EDC) site, the studied regions encompass a large range of surface accumulation rates and temperature conditions. Our δ15N profiles reveal a heterogeneous response of the firn structure to glacial-interglacial climatic changes. While firn densification simulations correctly predict TALDICE δ15N variations, they systematically fail to capture the large millennial-scale δ15N variations measured at BI and the δ15N glacial levels measured at JRI and EDML - a mismatch previously reported for central East Antarctic ice cores. New constraints of the EDML gas-ice depth offset during the Laschamp event (~41 ka) and the last deglaciation do not favour the hypothesis of a large convective zone within the firn as the explanation of the glacial firn model-δ15N data mismatch for this site. While we could not conduct an in-depth study of the influence of impurities in snow for firnification from the existing datasets, our detailed comparison between the δ15N profiles and firn model simulations under different temperature and accumulation rate scenarios suggests that the role of accumulation rate may have been underestimated in the current description of firnification models.
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1981-01-01
E oc vc li.’ r .IIuaJry 1.981 Office of’ Nav;il Rcs,.il vh Q# ,. 4 ,lL1 , 0r4i gT...Ic It, toil ill Who, (-, o) r i n partC ~S lort’Iic L o i f. 111V llll~ of tIc Ul ilLI7 )LA . .. L: 0 I [Ile:; . Sb c ~ T c It A I 1’: 1 w1 -iid ex...UlmA ioctlt.y Vc v jn- Ilic . P’or c v i ) L c1) 1 W I S I I t’,.ItL IV e y 10r- ILI I L v J c o 1) t, )I c rflv or ind ah- - tce isi - W 4i e L
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NASA Astrophysics Data System (ADS)
Guo, Hongbo; He, Xiaowei; Liu, Muhan; Zhang, Zeyu; Hu, Zhenhua; Tian, Jie
2017-03-01
Cerenkov luminescence tomography (CLT), as a promising optical molecular imaging modality, can be applied to cancer diagnostic and therapeutic. Most researches about CLT reconstruction are based on the finite element method (FEM) framework. However, the quality of FEM mesh grid is still a vital factor to restrict the accuracy of the CLT reconstruction result. In this paper, we proposed a multi-grid finite element method framework, which was able to improve the accuracy of reconstruction. Meanwhile, the multilevel scheme adaptive algebraic reconstruction technique (MLS-AART) based on a modified iterative algorithm was applied to improve the reconstruction accuracy. In numerical simulation experiments, the feasibility of our proposed method were evaluated. Results showed that the multi-grid strategy could obtain 3D spatial information of Cerenkov source more accurately compared with the traditional single-grid FEM.
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Engineering of a multi-station shoulder simulator.
Smith, Simon L; Li, Lisa; Joyce, Thomas J
2016-05-01
This work aimed to engineer a multi-station shoulder simulator in order to wear test shoulder prostheses using recognized shoulder activities of daily living. A bespoke simulator was designed, built and subject to commissioning trials before a first wear test was conducted. Five JRI Orthopaedics Reverse Shoulder VAIOS 42 mm prostheses were tested for 2.0 million cycles and a mean wear rate and standard deviation of 14.2 ± 2.1 mm(3)/10(6) cycles measured for the polymeric glenoid components. This result when adjusted for prostheses diameters and test conditions showed excellent agreement with results from hip simulator studies of similar materials in a lubricant of bovine serum. The Newcastle Shoulder Simulator is the first multi-station shoulder simulator capable of applying physiological motion and loading for typical activities of daily living. © IMechE 2016.
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Think tank (2) Its development and the current situation of the key organizations in Japan
NASA Astrophysics Data System (ADS)
Obara, Michio
There were some think tank businesses in Japan before the war. South Manchuria Railway Company established its Research Department for the purpose of getting power to control Manchuria as a colony, and got the good results. Think tank business was flourishing three times after the war. This business attracts much attention when the social and economic paradigm is going to change. Among the key large-scale think tanks in Japan, Nomura Research Institute, Ltd. (NRI) was the first to enhance the system functions by the merger, and posted think tank function up in the SI business. Mitsubishi Research Institute, Inc. (MRI) intends to be an orthodox think tank, and established an advanced research institute and the laboratory for R&D. Daiwa Institute of Research, Ltd. (DIR) focuses on economic forecast by using system. Fuji Research Institute. Corp. (FUJI RIC) focuses on survey and policy proposing in macro-economics, and analyzing technology. The Japan Research Institute, Ltd. (JRI) focuses on regional development, and R&D in advanced technology.
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Think tank (3) - Present activities of other representative organizations
NASA Astrophysics Data System (ADS)
Obara, Michio
There were some think tank businesses in Japan before the war. South Manchuria Railway Company established its Research Department for the purpose of getting power to control Manchuria as a colony, and got the good results. Think tank business was flourishing three times after the war. This business attracts much attention when the social and economic paradigm is going to change. Among the key large-scale think tanks in Japan, Nomura Research Institute, Ltd. (NRI) was the first to enhance the system functions by the merger, and posted think tank function up in the SI business. Mitsubishi Research Institute, Inc. (MRI) intends to be an orthodox think tank, and established an advanced research institute and the laboratory for R&D. Daiwa Institute of Research, Ltd. (DIR) focuses on economic forecast by using system. Fuji Research Institute, Corp. (FUJI RIC) focuses on survey and policy proposing in macro-economics, and analyzing technology. The Japan Research Institute, Ltd. (JRI) focuses on regional development, and R&D in advanced technology.
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Design of an Ada expert system shell for the VHSIC avionic modular flight processor
NASA Technical Reports Server (NTRS)
Fanning, F. Jesse
1992-01-01
The Embedded Computer System Expert System Shell (ES Shell) is an Ada-based expert system shell developed at the Avionics Laboratory for use on the VHSIC Avionic Modular Processor (VAMP) running under the Ada Avionics Real-Time Software (AARTS) Operating System. The ES Shell provides the interface between the expert system and the avionics environment, and controls execution of the expert system. Testing of the ES Shell in the Avionics Laboratory's Integrated Test Bed (ITB) has demonstrated its ability to control a non-deterministic software application executing on the VAMP's which can control the ITB's real-time closed-loop aircraft simulation. The results of these tests and the conclusions reached in the design and development of the ES Shell have played an important role in the formulation of the requirements for a production-quality expert system inference engine, an ingredient necessary for the successful use of expert systems on the VAMP embedded avionic flight processor.
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Analysis of Snow Bidirectional Reflectance from ARCTAS Spring-2008 Campaign
NASA Technical Reports Server (NTRS)
Lyapustin, A.; Gatebe, C. K.; Redemann, J.; Kahn, R.; Brandt, R.; Russell, P.; King, M. D.; Pedersen, C. A.; Gerland, S.; Poudyal, R.;
2010-01-01
The spring 2008 Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) experiment was one of major intensive field campaigns of the International Polar Year aimed at detailed characterization of atmospheric physical and chemical processes in the Arctic region. A part of this campaign was a unique snow bidirectional reflectance experiment on the NASA P-3B aircraft conducted on 7 and 15 April by the Cloud Absorption Radiometer (CAR) jointly with airborne Ames Airborne Tracking Sunphotometer (AATS) and ground-based Aerosol Robotic Network (AERONET) sunphotometers. The CAR data were atmospherically corrected to derive snow bidirectional reflectance at high 1 degree angular resolution in view zenith and azimuthal angles along with surface albedo. The derived albedo was generally in good agreement with ground albedo measurements collected on 15 April. The CAR snow bidirectional reflectance factor (BRF) was used to study the accuracy of analytical Ross-Thick Li-Sparse (RTLS), Modified Rahman-Pinty-Verstraete (MRPV) and Asymptotic Analytical Radiative Transfer (AART) BRF models. Except for the glint region (azimuthal angles phi less than 40 degrees), the best fit MRPV and RTLS models fit snow BRF to within 0.05. The plane-parallel radiative transfer (PPRT) solution was also analyzed with the models of spheres, spheroids, randomly oriented fractal crystals, and with a synthetic phase function. The latter merged the model of spheroids for the forward scattering angles with the fractal model in the backscattering direction. The PPRT solution with synthetic phase function provided the best fit to measured BRF in the full range of angles. Regardless of the snow grain shape, the PPRT model significantly over-/underestimated snow BRF in the glint/backscattering regions, respectively, which agrees with other studies. To improve agreement with experiment, we introduced a model of macroscopic snow surface roughness by averaging the PPRT solution
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NASA Astrophysics Data System (ADS)
Umezu, Yasuyoshi; Watanabe, Yuko; Ma, Ninshu
2005-08-01
Since 1996, Japan Research Institute Limited (JRI) has been providing a sheet metal forming simulation system called JSTAMP-Works packaged the FEM solvers of LS-DYNA and JOH/NIKE, which might be the first multistage system at that time and has been enjoying good reputation among users in Japan. To match the recent needs, "faster, more accurate and easier", of process designers and CAE engineers, a new metal forming simulation system JSTAMP-Works/NV is developed. The JSTAMP-Works/NV packaged the automatic healing function of CAD and had much more new capabilities such as prediction of 3D trimming lines for flanging or hemming, remote control of solver execution for multi-stage forming processes and shape evaluation between FEM and CAD. On the other way, a multi-stage multi-purpose inverse FEM solver HYSTAMP is developed and will be soon put into market, which is approved to be very fast, quite accurate and robust. Lastly, authors will give some application examples of user defined ductile damage subroutine in LS-DYNA for the estimation of material failure and springback in metal forming simulation.
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NASA Astrophysics Data System (ADS)
Glasser, N. F.; Scambos, T. A.
2009-12-01
We use optical satellite imagery (ASTER and Landsat) to document changes in the Prince Gustav Ice Shelf (PGIS) and its tributary glaciers before and after its 1995 collapse. Interpretation of a pre-collapse Landsat 4-5 TM image acquired in February 1988 shows that the ice shelf was fed primarily by Sjogren Glacier from the Antarctic Peninsula and by Rhoss Glacier from James Ross Island (JRI). In 1988, the PGIS contained numerous structural discontinuities (rifts and crevasses), which collectively indicate that ice-shelf break-up had commenced at least seven years before collapse. Meltwater ponds and streams were also common across its surface. After the ice shelf collapsed, Rhoss Glacier became a tidewater glacier and has since experienced rapid and continued recession. Between January 2001 and December 2006 (six to eleven years after the collapse of the PGIS), the front of Rhoss Glacier receded a total of 13.6 km. We conclude that where tributary glaciers become tidewater glaciers they react to ice-shelf removal by rapid and continued recession and that the response time of glaciers on the Antarctic Peninsula to ice-shelf removal is measured on annual to decadal timescales. This rapid recession, coupled with previously documented tributary glacier thinning and acceleration, indicates that Antarctic Peninsula glaciers are extremely sensitive to ice-shelf collapse.
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Quantum Corral Wave-function Engineering
NASA Astrophysics Data System (ADS)
Correa, Alfredo; Reboredo, Fernando; Balseiro, Carlos
2005-03-01
We present a theoretical method for the design and optimization of quantum corrals[1] with specific electronic properties. Taking advantage that spins are subject to a RKKY interaction that is directly controlled by the scattering of the quantum corral, we design corral structures that reproduce spin Hamiltonians with coupling constants determined a priori[2]. We solve exactly the bi-dimensional scattering problem for each corral configuration within the s-wave approximation[3] and subsequently the geometry of the quantum corral is optimized by means of simulated annealing[4] and genetic algorithms[5]. We demonstrate the possibility of automatic design of structures with complicated target electronic properties[6]. This work was performed under the auspices of the US Department of Energy by the University of California at the LLNL under contract no W-7405-Eng-48. [1] M. F. Crommie, C. P. Lutz and D. M. Eigler, Nature 403, 512 (2000) [2] D. P. DiVincenzo et al., Nature 408, 339 (2000) [3] G. A. Fiete and E. J. Heller, Rev. Mod. Phys. 75, 933 (2003) [4] M. R. A. T. N. Metropolis et al., J. Chem. Phys. 1087 (1953) [5] E. Aarts and J. K. Lenstra, eds. Local search in combinatorial problems (Princeton University Press, 1997) [6] A. A. Correa, F. Reboredo and C. Balseiro, Phys. Rev. B (in press).
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Eating behaviour associated with differences in conflict adaptation for food pictures.
Husted, Margaret; Banks, Adrian P; Seiss, Ellen
2016-10-01
The goal conflict model of eating (Stroebe, Mensink, Aarts, Schut, & Kruglanski, 2008) proposes differences in eating behaviour result from peoples' experience of holding conflicting goals of eating enjoyment and weight maintenance. However, little is understood about the relationship between eating behaviour and the cognitive processes involved in conflict. This study aims to investigate associations between eating behaviour traits and cognitive conflict processes, specifically the application of cognitive control when processing distracting food pictures. A flanker task using food and non-food pictures was used to examine individual differences in conflict adaptation. Participants responded to target pictures whilst ignoring distracting flanking pictures. Individual differences in eating behaviour traits, attention towards target pictures, and ability to apply cognitive control through adaptation to conflicting picture trials were analysed. Increased levels of external and emotional eating were related to slower responses to food pictures indicating food target avoidance. All participants showed greater distraction by food compared to non-food pictures. Of particular significance, increased levels of emotional eating were associated with greater conflict adaptation for conflicting food pictures only. Emotional eaters demonstrate greater application of cognitive control for conflicting food pictures as part of a food avoidance strategy. This could represent an attempt to inhibit their eating enjoyment goal in order for their weight maintenance goal to dominate. Copyright © 2016 Elsevier Ltd. All rights reserved.
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Micro-Pressure Sensors for Future Mars Missions
NASA Technical Reports Server (NTRS)
Catling, David C.
1996-01-01
The joint research interchange effort was directed at the following principal areas: u further development of NASA-Ames' Mars Micro-meteorology mission concept as a viable NASA space mission especially with regard to the science and instrument specifications u interaction with the flight team from NASA's New Millennium 'Deep-Space 2' (DS-2) mission with regard to selection and design of micro-pressure sensors for Mars u further development of micro-pressure sensors suitable for Mars The research work undertaken in the course of the Joint Research Interchange should be placed in the context of an ongoing planetary exploration objective to characterize the climate system on Mars. In particular, a network of small probes globally-distributed on the surface of the planet has often been cited as the only way to address this particular science goal. A team from NASA Ames has proposed such a mission called the Micrometeorology mission, or 'Micro-met' for short. Surface pressure data are all that are required, in principle, to calculate the Martian atmospheric circulation, provided that simultaneous orbital measurements of the atmosphere are also obtained. Consequently, in the proposed Micro-met mission a large number of landers would measure barometric pressure at various locations around Mars, each equipped with a micro-pressure sensor. Much of the time on the JRI was therefore spent working with the engineers and scientists concerned with Micro-met to develop this particular mission concept into a more realistic proposition.
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Revision of cemented hip arthroplasty using a hydroxyapatite-ceramic-coated femoral component.
Raman, R; Kamath, R P; Parikh, A; Angus, P D
2005-08-01
We report the clinical and radiological outcome of 86 revisions of cemented hip arthroplasties using JRI-Furlong hydroxyapatite-ceramic-coated acetabular and femoral components. The acetabular component was revised in 62 hips and the femoral component in all hips. The mean follow-up was 12.6 years and no patient was lost to follow-up. The mean age of the patients was 71.2 years. The mean Harris hip and Oxford scores were 82 (59 to 96) and 23.4 (14 to 40), respectively. The mean Charnley modification of the Merle d'Aubigné and Postel score was 5 (3 to 6) for pain, 4.9 (3 to 6) for movement and 4.4 (3 to 6) for mobility. Migration of the acetabular component was seen in two hips and the mean acetabular inclination was 42.6 degrees. The mean linear polyethylene wear was 0.05 mm/year. The mean subsidence of the femoral component was 1.9 mm and stress shielding was seen in 23 (28%) with bony ingrowth in 76 (94%). Heterotopic ossification was seen in 12 hips (15%). There were three re-revisions, two for deep sepsis and one for recurrent dislocation and there were no re-revisions for aseptic loosening. The mean EuroQol EQ-5D description scores and health thermometer scores were 0.69 (0.51 to 0.89) and 79 (54 to 95), respectively. With an end-point of definite or probable loosening, the probability of survival at 12 years was 93.9% and 95.6% for the acetabular and femoral components, respectively. Overall survival at 12 years, with removal or further revision of either component for any reason as the end-point, was 92.3%. Our study supports the continued use of this arthroplasty and documents the durability of hydroxyapatite-ceramic-coated components.
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NASA Technical Reports Server (NTRS)
Hebert, Martial
1999-01-01
This report describes a three-month research program undertook jointly by the Robotics Institute at Carnegie Mellon University and Ames Research Center as part of the Ames' Joint Research Initiative (JRI.) The work was conducted at the Ames Research Center by Mr. Liam Pedersen, a graduate student in the CMU Ph.D. program in Robotics under the supervision Dr. Ted Roush at the Space Science Division of the Ames Research Center from May 15 1999 to August 15, 1999. Dr. Martial Hebert is Mr. Pedersen's research adviser at CMU and is Principal Investigator of this Grant. The goal of this project is to investigate and implement methods suitable for a robotic rover to autonomously identify rocks and minerals in its vicinity, and to statistically characterize the local geological environment. Although primary sensors for these tasks are a reflection spectrometer and color camera, the goal is to create a framework under which data from multiple sensors, and multiple readings on the same object, can be combined in a principled manner. Furthermore, it is envisioned that knowledge of the local area, either a priori or gathered by the robot, will be used to improve classification accuracy. The key results obtained during this project are: The continuation of the development of a rock classifier; development of theoretical statistical methods; development of methods for evaluating and selecting sensors; and experimentation with data mining techniques on the Ames spectral library. The results of this work are being applied at CMU, in particular in the context of the Winter 99 Antarctica expedition in which the classification techniques will be used on the Nomad robot. Conversely, the software developed based on those techniques will continue to be made available to NASA Ames and the data collected from the Nomad experiments will also be made available.
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Aberrant Food Choices after Satiation in Human Orexin-Deficient Narcolepsy Type 1
van Holst, Ruth Janke; van der Cruijsen, Lisa; van Mierlo, Petra; Lammers, Gert Jan; Cools, Roshan; Overeem, Sebastiaan; Aarts, Esther
2016-01-01
Study Objectives: Besides influencing vigilance, orexin neurotransmission serves a variety of functions, including reward, motivation, and appetite regulation. As obesity is an important symptom in orexin-deficient narcolepsy, we explored the effects of satiety on food-related choices and spontaneous snack intake in patients with narcolepsy type 1 (n = 24) compared with healthy matched controls (n = 19). In additional analyses, we also included patients with idiopathic hypersomnia (n = 14) to assess sleepiness-related influences. Methods: Participants were first trained on a choice task to earn salty and sweet snacks. Next, one of the snack outcomes was devalued by having participants consume it until satiation (i.e., sensory-specific satiety). We then measured the selective reduction in choices for the devalued snack outcome. Finally, we assessed the number of calories that participants consumed spontaneously from ad libitum available snacks afterwards. Results: After satiety, all participants reported reduced hunger and less wanting for the devalued snack. However, while controls and idiopathic hypersomnia patients chose the devalued snack less often in the choice task, patients with narcolepsy still chose the devalued snack as often as before satiety. Subsequently, narcolepsy patients spontaneously consumed almost 4 times more calories during ad libitum snack intake. Conclusions: We show that the manipulation of food-specific satiety has reduced effects on food choices and caloric intake in narcolepsy type 1 patients. These mechanisms may contribute to their obesity, and suggest an important functional role for orexin in human eating behavior. Clinical Trials Registration: Study registered at Netherlands Trial Register. URL: www.trialregister.nl. Trial ID: NTR4508. Citation: van Holst RJ, van der Cruijsen L, van Mierlo P, Lammers GJ, Cools R, Overeem S, Aarts E. Aberrant food choices after satiation in human orexindeficient narcolepsy type 1. SLEEP 2016
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NASA Astrophysics Data System (ADS)
Capron, E.; Landais, A.; Buiron, D.; Cauquoin, A.; Chappellaz, J.; Debret, M.; Jouzel, J.; Leuenberger, M.; Martinerie, P.; Masson-Delmotte, V.; Mulvaney, R.; Parrenin, F.; Prié, F.
2012-12-01
Correct estimate of the firn lock-in depth is essential for correctly linking gas and ice chronologies in ice cores studies. Here, two approaches to constrain the firn depth evolution in Antarctica are presented over the last deglaciation: output of a firn densification model and measurements of δ15N of N2 in air trapped in ice core. Since the firn densification process is largely governed by surface temperature and accumulation rate, we have investigated four ice cores drilled in coastal (Berkner Island, BI, and James Ross Island, JRI) and semi coastal (TALDICE and EPICA Dronning Maud Land, EDML) Antarctic regions. Combined with available δ15N measurements performed from the EPICA Dome C (EDC) site, the studied regions encompass a large range of surface accumulation rate and temperature conditions. While firn densification simulations are able to correctly represent most of the δ15N trends over the last deglaciation measured in the EDC, BI, TALDICE and EDML ice cores, they systematically fail to capture BI and EDML δ15N glacial levels, a mismatch previously seen for Central East Antarctic ice cores. Using empirical constraints of the EDML gas-ice depth offset during the Laschamp event (~ 41 ka), we can rule out the existence of a large convective zone as the explanation of the glacial firn model-δ15N data mismatch for this site. The good match between modelled and measured δ15N at TALDICE as well as the lack of any clear correlation between insoluble dust concentration in snow and δ15N records in the different ice cores suggest that past changes in loads of impurities are not the only main driver of glacial-interglacial changes in firn lock-in depth. We conclude that firn densification dynamics may instead be driven mostly by accumulation rate changes. The mismatch between modelled and measured δ15N may be due to inaccurate reconstruction of past accumulation rate or underestimated influence of accumulation rate in firnification models.
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Non-Dipole Features of the Geomagnetic Field May Persist for Millions of Years
NASA Astrophysics Data System (ADS)
Biasi, J.; Kirschvink, J. L.
2017-12-01
Here we present paleointensity results from within the South Atlantic Anomaly (SAA), which is a large non-dipole feature of the geomagnetic field. Within the area of the SAA, anomalous declinations, inclinations, and intensities are observed. Our results suggest that the SAA has been present for at least 5 Ma. This is orders-of-magnitude greater than any previous estimate, and suggests that some non-dipole features do not `average out' over geologic time, which is a fundamental assumption in all paleodirectional studies. The SAA has been steadily growing in size since the first magnetic measurements were made in the South Atlantic, and it is widely believed to have appeared 400 years ago. Recent studies from South Africa (Tarduno et al. (2015)) and Tristan da Cunha (Shah et al. (2016)) have suggested that the SAA has persisted for 1 ka and 96 ka respectively. We conducted paleointensity (PI) experiments on basaltic lavas from James Ross Island, on the Antarctic Peninsula. This large shield volcano has been erupting regularly over the last 6+ Ma (dated via Ar/Ar geochronology), and therefore contains the most complete volcanostratigraphic record in the south Atlantic. Our PI experiments used the Thellier-Thellier method, the IZZI protocol, and the same selection criteria as the Lawrence et al. (2009) study of Ross Island lavas (near McMurdo Station), which is the only comparable PI study on the Antarctic continent. We determined an average paleointensity at JRI of 13.8±5.2 μT, which is far lower than what we would expect from a dipole field (55 μT). In addition, this is far lower than the current value over James Ross Island of 36 μT. These results support the following conclusions: The time-averaged field model of Juarez et al. (1998) and Tauxe et al. (2013) is strongly favored by our PI data. The SAA has persisted over James Ross Island for at least 5 Ma, and has not drifted significantly over that time. The strength of non-dipole features such as the SAA
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NASA Astrophysics Data System (ADS)
Snilstveit Hoem, Frida; Ninnemann, Ulysses S.; Kleiven, Helga (Kikki) F.; Irvali, Nil
2017-04-01
period of generally low IRD, coincides with Little Ice Age at 600 cal yr B.P. The local surface water hydrography appears relatively stable over the past 4000 years with the planktonic δ18O signal indicating centennial-millennial scale changes of typically ≤1˚ C (Δ0.22) and notably smaller in amplitude than the regional warming observed over the past century. The lack of correlation between surface water physical properties and IRD in the downcore records, suggests that IRD is not reflecting iceberg survival but rather changes in the supply (WAIS dynamics) or routing. Consistent with this interpretation, IRD covaries with climate on the Antarctic Peninsula (from JRI ice core) over the past 4 kyr with cooler conditions and lower amounts of IRD over much of the past two millennia than occurred earlier in the neoglaciation. Both records indicate a recovery with warming and increased IRD prior to industrialization. This relationship is consistent with the hypothesis that climate and specifically ocean temperatures were important for modulating WAIS discharge rates over the past few millennia.
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TEM analysis of the initial stages of BaSO4 crystallization
NASA Astrophysics Data System (ADS)
Ruiz Agudo, Cristina; Putnis, Christine V.; Ruiz Agudo, Encarnación; Putnis, Andrew
2014-05-01
observed ex-situ in a Transmission Electron Microscope. We found that barite precipitation involves the initial formation of nanometer-size (5-10 nm) particles that fuse in an oriented way to form larger particles. Two hierarchical levels of aggregation are observed: first, the aggregation of 5-10 nm particles to form larger, but still nanometer-sized (20-60 nm) particles. In a second stage, these latter particles aggregate to produce larger single crystals (200-500 nm). No evidence of an amorphous or crystalline precursor phase previous to crystalline barite was found. These results are of importance for the design of scale prevention methods, particularly in the choice of the most suitable scale inhibitor. Gebauer D., Cölfen H., Verch A. and Antonietti M. (2009) The multiple roles of additives in CaCO3 crystallization: a quantitative case study. Adv. Mater. 21, 435-439. Gebauer D., Völkel A. and Cölfen H. (2008) Stable prenucleation calcium carbonate clusters. Science 332, 1819-1822. Van Driessche A.E.S., Benning L.G., Rodriguez-Blanco J. D., Ossorio M., Bots P. and García-Ruiz J. M. (2012) The role and implications of bassanite as a stable precursor phase to gypsum precipitation. Science 336, 69-71. Baumgartner J., Dey A., Bomans P. H. H., Le Coadou C., Fratzl P., Sommerdijk N. A. J. M. and Faivre D. (2013) Nucleation and growth of magnetite from solution. Nature 12, 310-314. Li D., Nielsen M.H., Lee J.R.I, Frandsen C., Banfield J.F. and De Yoreo J.J.(2012) Direction-Specific Interactions Control Crystal Growth by Oriented Attachment. Science 336, 1014-1018.
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NASA Astrophysics Data System (ADS)
Rowley-Neale, Samuel J.; Brownson, Dale A. C.; Smith, Graham C.; Sawtell, David A. G.; Kelly, Peter J.; Banks, Craig E.
2015-10-01
support materials, namely edge plane pyrolytic graphite (EPPG), glassy carbon (GC), boron-doped diamond (BDD) and screen-printed graphite electrodes (SPE), we critically evaluate the reported electrocatalytic performance of unmodified and MoS2 modified electrodes towards the HER. Surprisingly, current literature focuses almost exclusively on the use of GC as an underlying support electrode upon which HER materials are immobilised. 2D MoS2 nanosheet modified electrodes are found to exhibit a coverage dependant electrocatalytic effect towards the HER. Modification of the supporting electrode surface with an optimal mass of 2D MoS2 nanosheets results in a lowering of the HER onset potential by ca. 0.33, 0.57, 0.29 and 0.31 V at EPPG, GC, SPE and BDD electrodes compared to their unmodified counterparts respectively. The lowering of the HER onset potential is associated with each supporting electrode's individual electron transfer kinetics/properties and is thus distinct. The effect of MoS2 coverage is also explored. We reveal that its ability to catalyse the HER is dependent on the mass deposited until a critical mass of 2D MoS2 nanosheets is achieved, after which its electrocatalytic benefits and/or surface stability curtail. The active surface site density and turn over frequency for the 2D MoS2 nanosheets is determined, characterised and found to be dependent on both the coverage of 2D MoS2 nanosheets and the underlying/supporting substrate. This work is essential for those designing, fabricating and consequently electrochemically testing 2D nanosheet materials for the HER. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr05164a|ART
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Analytical phase diagrams for colloids and non-adsorbing polymer.
Fleer, Gerard J; Tuinier, Remco
2008-11-04
We review the free-volume theory (FVT) of Lekkerkerker et al. [Europhys. Lett. 20 (1992) 559] for the phase behavior of colloids in the presence of non-adsorbing polymer and we extend this theory in several aspects: (i) We take the solvent into account as a separate component and show that the natural thermodynamic parameter for the polymer properties is the insertion work Pi(v), where Pi is the osmotic pressure of the (external) polymer solution and v the volume of a colloid particle. (ii) Curvature effects are included along the lines of Aarts et al. [J. Phys.: Condens. Matt. 14 (2002) 7551] but we find accurate simple power laws which simplify the mathematical procedure considerably. (iii) We find analytical forms for the first, second, and third derivatives of the grand potential, needed for the calculation of the colloid chemical potential, the pressure, gas-liquid critical points and the critical endpoint (cep), where the (stable) critical line ends and then coincides with the triple point. This cep determines the boundary condition for a stable liquid. We first apply these modifications to the so-called colloid limit, where the size ratio q(R)=R/a between the radius of gyration R of the polymer and the particle radius a is small. In this limit the binodal polymer concentrations are below overlap: the depletion thickness delta is nearly equal to R, and Pi can be approximated by the ideal (van't Hoff) law Pi=Pi(0)=phi/N, where phi is the polymer volume fraction and N the number of segments per chain. The results are close to those of the original Lekkerkerker theory. However, our analysis enables very simple analytical expressions for the polymer and colloid concentrations in the critical and triple points and along the binodals as a function of q(R). Also the position of the cep is found analytically. In order to make the model applicable to higher size ratio's q(R) (including the so-called protein limit where q(R)>1) further extensions are needed. We
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Strong and Electroweak Matter 2004
NASA Astrophysics Data System (ADS)
Eskola, Kari J.; Kainulainen, Kimmo; Kajantie, Keijo; Rummukainen, Kari
results confront models / M. D'Elia and M. P. Lombardo -- Singlet free energies of a static quark-antiquark pair / K. Petrov -- Contributions to transport theory from multi-particle interactions and production processes / M. E. Carrington -- Transport coefficients and the 2PI effective action in the large N limit / G. Aarts and J. M. Martinez Resco -- Thermal features far from equilibrium: prethermalization / S. Borsányi -- QCD phase diagram at small Baryon densities from imaginary [symbol]: status report / O. Philipsen and Ph. de Forcrand -- Two loop renormalisation of the magnetic coupling in hot QCD and spatial Wilson loop / P. Giovannangeli -- Thermodynamics of deconfined QCD at small and large chemical potential / A. Ipp -- Evading the infrared problem of thermal QCD / Y. Schroder -- Chiral mesons in hot matter / A. Gómez Nicola, F. J. Llanes-Estrada and J. R. Peláez -- Thermal production of axinos in the early universe / A. Brandenburg and F. D. Steffen -- The 2-PI-1/N approximation applied to tachyonic preheating / A. Tranberg, A. Arrizabalaga and J. Smit -- Nonequilibrium dynamics in scalar hybrid models / J. Baacke and A. Heinen -- Photon mass in inflation and nearly minimal magnetogenesis / T. Prokopec -- Transport equations for chiral fermions to order [symbol] and electroweak Baryogenesis / S. Weinstock, M. G. Schmidt and T. Prokopec -- The gapless 2SC phase / M. Huang and I. A. Shovkovy -- Gapless CFL and its competition with mixed phases / M. Alford, C. Kouvaris and K. Rajagopal -- Transport coefficients in color superconducting quark matter / C. Manuel -- Renormalization and resummation in finite temperature field theories / A. Jakovác and Zs. Szép -- Renormalization and gauge symmetry for 2PI effective actions / U. Reinosa -- Out-of-equilibrium massless Schwinger model / R. F. Alvarez-Estrada -- Selfconsistent calculations of hadrons at finite temperature / C. Beckmann -- Fermion production in classical fields / D. D. Dietrich -- Numerical study of
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PREFACE: The Eighth Liquid Matter Conference The Eighth Liquid Matter Conference
NASA Astrophysics Data System (ADS)
Dellago, Christoph; Kahl, Gerhard; Likos, Christos N.
2012-07-01
interface tension of flat and curved interfaces from Monte Carlo simulationsA Tröster and K Binder Phase diagrams of particles with dissimilar patches: X-junctions and Y-junctionsJ M Tavares and P I C Teixeira The unbearable heaviness of colloids: facts, surprises, and puzzles in sedimentationRoberto Piazza, Stefano Buzzaccaro and Eleonora Secchi Exploring water and other liquids at negative pressureFrédéric Caupin, Arnaud Arvengas, Kristina Davitt, Mouna El Mekki Azouzi, Kirill I Shmulovich, Claire Ramboz, David A Sessoms and Abraham D Stroock The configurational space of colloidal patchy polymers with heterogeneous sequencesIvan Coluzza and Christoph Dellago Repeated sorption of water in SBA-15 investigated by means of in situ small-angle x-ray scatteringM Erko, D Wallacher, G H Findenegg and O Paris Transition of the hydration state of a surfactant accompanying structural transitions of self-assembled aggregatesM Hishida and K Tanaka The effects of topology on the structural, dynamic and mechanical properties of network-forming materialsMark Wilson Surface tension of an electrolyte-air interface: a Monte Carlo studyAlexandre Diehl, Alexandre P dos Santos and Yan Levin Water and other tetrahedral liquids: order, anomalies and solvationB Shadrack Jabes, Divya Nayar, Debdas Dhabal, Valeria Molinero and Charusita Chakravarty Diffusion coefficient and shear viscosity of rigid water modelsSami Tazi, Alexandru Boţan, Mathieu Salanne, Virginie Marry, Pierre Turq and Benjamin Rotenberg Phase behaviour of colloidal assemblies on 2D corrugated substratesSamir El Shawish, Emmanuel Trizac and Jure Dobnikar Structural properties of dendrimer-colloid mixturesDominic A Lenz, Ronald Blaak and Christos N Likos Fluid-fluid demixing of off-critical colloid-polymer systems confined between parallel platesE A G Jamie, R P A Dullens and D G A L Aarts Simulations of nematic homopolymer melts using particle-based models with interactions expressed through collective variablesKostas Ch
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EDITORIAL: Colloidal suspensions Colloidal suspensions
NASA Astrophysics Data System (ADS)
Petukhov, Andrei; Kegel, Willem; van Duijneveldt, Jeroen
2011-05-01
grateful recipients of many such notes ourselves. Visitors to Henk's office would often be treated to a demonstration experiment (for instance, birefringent suspensions) and a range of hand-made models designed to illustrate complex concepts (such as multidimensional phase diagrams). Henk's relationship with his students usually extends well after graduation, and many have benefitted from Henk's advice as a mentor. In spite of his scientific standing, Henk is down to earth; he is a pleasant and warm person, with a deep interest in people. He has many friends all over the world. At the same time, he does not eschew scientific debate. He takes a dim view of pretentious work, especially when it seems that inconvenient data has been neglected. Typically though he will comment in a way that avoids embarrassment and that motivates a redoubled effort. Henk's career will be celebrated at a symposium to be held in Amsterdam in June 2011. This special issue contains invited contributions by speakers at this symposium, as well as by other collaborators, colleagues, former students, and friends. The authors were free to choose their topics. We have grouped their contributions into a number of themes. The wide range of subjects mirrors Henk's interests and the research themes reviewed above are well represented. Henk, this special issue is for you—we hope you will enjoy it! References [1] Lekkerkerker H N W, Poon W C-K, Pusey P N, Stroobants A and Warren P B 1992 Europhys. Lett. 20 559 [2] Aarts D G A L, Schmidt M and Lekkerkerker H N W 2004 Science 304 847 [3] Frenkel D, Lekkerkerker H N W and Stroobants A 1988 Nature 332 822 [4] Vroege G J and Lekkerkerker H N W 1992 Rep. Prog. Phys. 55 1241 [5] Buining P A, Pathmamanoharan C, Jansen J B H and Lekkerkerker H N W 1991 J. Am. Ceram. Soc. 74 1303 [6] van der Kooij F M and Lekkerkerker H N W 1998 J. Phys. Chem. B 102 7829 [7] van der Kooij F M, Kassapidou K and Lekkerkerker H N W 2000 Nature 406 868 [8] Anderson V J and Lekkerkerker H